Magnetic
Therapy and Nerve Regeneration; a research bibliography.
Pulsed
magnetic field therapy found effective at regenerating nerve tissue in studies
performed since the 1970's. Dispite being found to be effective and safe,
these techniques have never been applied to medical practice due to their simplicity
and effectiveness. Where pulse repetition rate (frequency measured
in Hertz) and magnetic flux density (amplitude measured in Gauss or Tesla) are
both within certain parameters, pulsed magnetic field research has proven that
PEMF's are capable of equal or better results than conventional therapies and
invasive procedures without side effects or risk of infection. Pulsed electromagnetic
field research has proven routinely that PEMF therapy is capable of inducing substantial
healing even where conventional medicine has failed.
Beside promoting various healing mechanisms, pulsed electromagnetic field therapy
has been found to have substantially beneficial neuroendocrine, neurological and
psychological effects; as well as having ability to promote bone, tissue and nerve
regeneration.
BBC NEWS: Tuesday, 11 May, 2004, 09:13 GMT 10:13 UK
Doctors at Imperial College London administered magnetic stimulation to the
brains of people with partial damage to their spinal cord. The therapy led to
improved muscle and limb movement, and increased ability to feel sensations.
Details of the technique - known as repetitive transcranial magnetic
stimulation (rTMS) - are published in the journal Spinal Cord. It works by using
an electromagnet placed on the scalp to generate brief magnetic pulses, about
the strength of an MRI scan. These pulses stimulate the part of the brain called
the cerebral cortex.
The technique was tested on four patients with what are known as
incomplete spinal cord injuries. This is where the spinal cord has not been entirely
severed, but the patient has still lost the ability to move or feel properly below
the injury point.
Researcher Dr Nick Davey said: "Through rTMS we may be able to help
people who have suffered partial injuries to the spinal cord recover some of their
movement and feeling. "We think it works by strengthening the information
leaving the brain through the undamaged neurons in the spinal cord. It may work
like physiotherapy but instead of repeating a physical task, the machine activates
the surviving nerves to strengthen their connections."
The patients had all sustained their injuries at least 18 months
previously and had already received conventional rehabilitation including physiotherapy.
They were all considered stable in that they were no longer undergoing natural
improvement. The patients received both real and sham rTMS treatment over
a three-week period. The rTMS treatment involved five consecutive days of magnetic
stimulation for one hour per day.
The researchers focused on a phenomenon called intracortical inhibition
which makes it easier for message from the brain to pass down the spinal cord
to the rest of the body. They found rTMS treatment resulted in a 37.5% drop
in intracortical inhibition, compared with normal physiotherapy.
This reduction in intracortical inhibition was accompanied by
improvement in both motor and sensory function, which lasted for at least three
weeks after the treatment. Dr Davey said: "Despite this, we still need
to be extremely careful in interpreting these results as we only sampled a small
number of patients.
"Further studies on larger groups of patients will need to be carried
out before we will know if this treatment is fully effective. "Similarly we have
no idea how long the treatment benefits will last over a longer period."
The treatment was originally designed to treat psychiatric disorders,
and has been used in treating some of the symptoms of schizophrenia.
Several hundred
pulsed electromagnetic field therapy citations contained in our
research bibliographies are linked directly to PubMed a service of the U.S. National Library of Medicine and the U.S. National Institutes of Health.
These studies are offered for your education only and are not intended as promotional
material for EarthPulse™ Technologies, LLC.
See
also; Sandyk R, Anninos
PA , Jacobson
JI; three pioneers of electromagnetic field therapy to treat Parkinson's, Alzheimer's and epilepsy.
PEMF
Background:
Research
Bibliographies:
EarthPulse
research:
Altern Ther Health Med. 2006 Sep-Oct;12(5):42-9.Links
Regenerative effects of pulsed magnetic field on injured peripheral nerves.
Mert T, Gunay I, Gocmen C, Kaya M, Polat S.
Department of Biophysics, University of Cukurova School of Medicine, Adana, Turkey.
Previous studies confirm that pulsed magnetic field (PMF) accelerates
functional recovery after a nerve crush lesion. The contention that PMF
enhances the regeneration is still controversial, however. The
influence of a new PMF application protocol (trained PMF) on nerve
regeneration was studied in a model of crush injury of the sciatic
nerve of rats. To determine if exposure to PMF influences regeneration,
we used electrophysiological recordings and ultrastructural
examinations. After the measurements of conduction velocity, the
sucrose-gap method was used to record compound action potentials (CAPs)
from sciatic nerves. PMF treatment during the 38 days following the
crush injury enhanced the regeneration. Although the axonal
ultrastructures were generally normal, slight to moderate myelin sheath
degeneration was noted at the lesion site. PMF application for 38 days
accelerated nerve conduction velocity, increased CAP amplitude and
decreased the time to peak of the CAP. Furthermore, corrective effects
of PMF on. the abnormal characteristics of sensory nerve fibers were
determined. Consequently, long-periodic trained-PMF may promote both
morphological and electrophysiological properties of the injured
nerves. In addition, corrective effects of PMF on sensory fibers may be
considered an important finding for neuropathic pain therapy.
Bioelectromagnetics. 2005 Jan;26(1):20-7. Links
Pulsed electromagnetic fields induce peripheral nerve regeneration and endplate enzymatic changes.
De Pedro JA, Pérez-Caballer AJ, Dominguez J, Collía F, Blanco J, Salvado M.
Department of Orthopaedics, University Hospital of Salamanca, Salamanca, Spain. jpedrom@usal.es
An experimental study was carried out in rats with the purpose of
demonstrating the capacity of pulsed electromagnetic fields (PEMFs) to
stimulate regeneration of the peripheral nervous system (PNS). Wistar
and Brown Norway (BN) rats were used. Direct sciatic nerve anastomoses
were performed after section or allograft interposition. Treatment
groups then received 4 weeks of PEMFs. Control groups received no
stimulation. The evaluation of the results was carried out by
quantitative morphometric analysis, demonstrating a statistically
significant increase in regeneration indices (P < 0.05) in the
stimulated groups (9000 +/- 5000 and 4000 +/- 6000) compared to the
non-stimulated groups (2000 +/- 4000 and 700 +/- 200). An increase of
NAD specific isocitrate dehydrogenase (IDH) activity was found along
with an increase in the activity of acetyl cholinesterase at the motor
plate. The present study might lead to the search for new alternatives
in the stimulation of axonal regenerative processes in the PNS and
other possible clinical applications. 2004 Wiley-Liss, Inc.
Spine. 2003 Dec 15;28(24):2660-6. Links
Exposure to pulsed magnetic fields enhances motor recovery in cats after spinal cord injury.
Crowe MJ, Sun ZP, Battocletti JH, Macias MY, Pintar FA, Maiman DJ.
Neuroscience Research Laboratories, The Clement J. Zablocki VA Medical Center, Milwaukee, WI 53295, USA. mcrowe@mcw.edu
STUDY DESIGN: Animal model study of eight healthy commercial cats was
conducted. OBJECTIVE: To determine whether pulsed electromagnetic field
(PMF) stimulation results in improvement of function after contusive
spinal cord injury in cats. SUMMARY OF BACKGROUND DATA: PMF stimulation
has been shown to enhance nerve growth, regeneration, and functional
recovery of peripheral nerves. Little research has been performed
examining the effects of PMF stimulation on the central nervous system
and no studies of PMF effects on in vivo spinal cord injury (SCI)
models have been reported. MATERIALS AND METHODS: PMF stimulation was
noninvasively applied for up to 12 weeks to the midthoracic spine of
cats with acute contusive spinal cord injury. The injury was produced
using a weight-drop apparatus. Motor functions were evaluated with the
modified Tarlov assessment scale. Morphologic analyses of the injury
sites and somatosensory-evoked potential measurements were conducted to
compare results between PMF-stimulated and control groups. RESULTS:
There was a significant difference in locomotor recovery between the
PMF-stimulated and control groups. Although not statistically
significant, PMF-stimulated spinal cords demonstrated greater sparing
of peripheral white matter and smaller lesion volumes compared to
controls. Somatosensory-evoked potential measurements indicated that
the PMF-stimulated group had better recovery of preinjury waveforms
than the control group; however, this observation also was not
statistically significant because of the small sample size.
CONCLUSIONS: This preliminary study indicates that pulsed magnetic
fields may have beneficial effects on motor function recovery and
lesion volume size after acute spinal cord injury.
J Reconstr Microsurg. 1999 Aug;15(6):427-31.Links
Using a direct current electrical field to promote spinal-cord regeneration.
Shen NJ, Wang SC.
Department of Orthopedics, People's Hospital of Hainan Province, Haikou, China.
The authors used a direct current electrical field to promote
spinal-cord regeneration in a canine model. Thirty-two dogs were
randomly divided into four groups. Complete spinal-cord injury was
induced, and electrical stimulators were then placed in the animals.
Group 1 served as controls; Groups 2 to 4 were experimental groups,
with varying stimulator voltages: 0V in Group 1, 12V in Groups 2 and 4,
and 6V in Group 3, with the stimulator implanted 6 hr after spinal-cord
injury in Group 4. Functional, electrophysiologic and morphometric
assessments were carried out 1 to 3 months postoperatively. Results
showed that spinal-cord function, cortical somatosensory evoked
potentials, number of neurons, sectional area of neurons, and Nissl
body density in the experimental groups were much better than those in
the control group. In addition, all the indices in Group 2 were better
than those in Groups 3 and 4. This indicated that direct current
electrical stimulation could effectively promote spinal-cord
regeneration and functional recovery in this model. The 12V voltage was
safe for the animals. The stimulator was not rejected by the host for a
relatively long period of time.
Plast Reconstr Surg. 1984 Feb;73(2):173-83.
Pulsing electromagnetic field therapy in nerve regeneration: an experimental
study in the cat. Orgel MG, O'Brien WJ, Murray HM.
A multidisciplinary approach to the study of peripheral nerve regeneration in
the cat has been presented. The purpose of this work has been to determine if
pulsing electromagnetic field (PEMF) therapy can enhance peripheral nerve
regeneration after injury. In equal groups of animals, two types of pulsing
electromagnetic field treatment were compared with untreated controls. All
animals underwent quantitative electrophysiologic and morphologic assessment at
the area of injury. In addition, muscle fiber sizing in the periphery and
retrograde labeling of anterior horn motoneurons with horseradish peroxidase
were studied. Results have shown no statistical differences between the groups
in electrophysiologic or morphologic parameters. However, in animals treated
with a pulse-burst electromagnetic field there was a statistically significant
improvement in the labeling and localization of anterior horn cells in the
central nervous system. These results indicate that pulse-burst electromagnetic
radiation can increase the numbers of motor neurons that reestablish appropriate
connections to the periphery after nerve injury. It remains to be seen if this
improved spinal cord organization can translate to improved peripheral
functional return.
PMID: 6695016 [PubMed - indexed for MEDLINE]
2: Clin Orthop. 1983 Dec;(181):283-90.
Effect of weak, pulsing electromagnetic fields on neural regeneration in the
rat.
Ito H, Bassett CA.
The short- and long-term effects of pulsed electromagnetic fields (PEMFs) on the
rate and quality of peripheral nerve regeneration were studied. High bilateral
transections of rat sciatic nerves were surgically approximated (a 1-mm gap was
left) and shielded with a Silastic sleeve. Animals were exposed to PEMFs for two
to 14 weeks after operation. Three groups of 20 rats each (control rats and rats
undergoing 12- and 24-hour/day PEMF exposure) were killed at two weeks.
Histologically, regenerating axons had penetrated the distal stump nearly twice
as far in the PEMF-exposed animals as in the control animals. Return of motor
function was judged two to 14 weeks after operation by the load cell-measured,
plantar-flexion force produced by neural stimulation proximal to the transection
site. Motor function returned earlier in experimental rats and to significantly
higher load levels than in control rats. Nerves from animals functioning 12-14
weeks after operation had less interaxonal collagen, more fiber-containing axis
cylinders, and larger fiber diameters in the PEMF-exposed group than in the
control rats. Histologic and functional data indicate that PEMFs improve the
rate and quality of peripheral nerve regeneration in the severed rat sciatic
nerve by a factor of approximately two.
PMID: 6641063 [PubMed - indexed for MEDLINE]
3: J Hand Surg [Br]. 1984 Jun;9(2):105-12.
An experimental study of the effects of pulsed electromagnetic field (Diapulse)
on nerve repair.
Raji AM.
This study investigates the effects of a pulsed electromagnetic field (PEMF)
(Diapulse) on experimentally divided and sutured common peroneal nerves in rats.
Evidence is presented to show that PEMF accelerates recovery of use of the
injured limb and enhances regeneration of damaged nerves.
PMID: 6747406 [PubMed - indexed for MEDLINE]
4: J Bone Joint Surg Br. 1983 Aug;65(4):478-92.
Effects of high-peak pulsed electromagnetic field on the degeneration and
regeneration of the common peroneal nerve in rats.
Raji AR, Bowden RE.
Apart from preliminary notices of present work, previous reports of experimental
and clinical trials of the effects of a high-peak pulsed electromagnetic field
(PEMF) on degeneration and regeneration of peripheral nerves lacked statistical
analysis. Therefore, we designed experiments with standardised operative,
histological, cytological and morphometric techniques to assess the effect of
PEMF on lesions of the common peroneal nerves in paired male rats matched for
age, environmental conditions and level and type of lesion. One of two types of
lesion was induced in the left common peroneal nerve: in 12 pairs of rats the
nerve was crushed just above the knee and in the remaining 12 pairs the nerve
was cut and immediately sutured at the same level. The right common peroneal
nerve of each rat served as a control. Animals received 15 minutes of PEMF
produced by a Diapulse machine or sham treatment daily for periods ranging from
three and a half days to eight weeks after injury. Healthy nerves were
unaffected, but after damage there were statistically significant differences
between PEMF treated and sham treated rats. PEMF accelerated the recovery of
injured limbs and the degeneration, regeneration and maturation of myelinated
axons; epineural, perineural and intraneural fibrosis was reduced; and the
luminal cross-sectional area of intraneural vessels increased after both types
of lesion. Findings are discussed and the need for clinical trials is stressed.
PMID: 6603461 [PubMed - indexed for MEDLINE]
5: Nippon Ika Daigaku Zasshi. 1986 Aug;53(4):321-31.
[Nerve regeneration with pulsing electromagnetic field stimulation, with special
reference to nerve conduction velocity]
[Article in Japanese]
Narita T.
PMID: 3760123 [PubMed - indexed for MEDLINE]
6: Paraplegia. 1976 May;14(1):12-20.
Experimental regeneration in peripheral nerves and the spinal cord in laboratory
animals exposed to a pulsed electromagnetic field.
Wilson DH, Jagadeesh P.
Peripheral nerve section and suture was performed in 132 rats. Postoperatively
half the animals were exposed to a pulsed electromagnetic field each day and
half were kept as controls. Nerve conduction studies, histology and nerve fibre
counts all indicated an increased rate of regeneration in the treated animals.
A
similar controlled study of spinal cord regeneration following hemicordotomy in
cats has been started, and preliminary results indicate that when the animals
are sacrificed three months after the hemicordotomy, the pulsed electromagnetic
therapy has induced nerve fibre regeneration across the region of the scar.
PMID: 180476 [PubMed - indexed for MEDLINE]
7: Plast Reconstr Surg. 1989 Feb;83(2):301-8.
Effect of a high-intensity static magnetic field on sciatic nerve regeneration
in the rat.
Cordeiro PG, Seckel BR, Miller CD, Gross PT, Wise RE.
Department of Plastic and Reconstructive Surgery, Lahey Clinic Medical Center,
Burlington, Mass.
The effect of a high-intensity static magnetic field on peripheral nerve
regeneration is evaluated in rat sciatic nerve. Forty-four rats underwent
sciatic nerve repair using polyethylene nerve guides. Postoperatively, the
animals were exposed to a 1-tesla magnetic field for 12 hours per day for 4
weeks with appropriate controls. Our results demonstrate that a 1-tesla static
magnetic field has no statistically significant effect on nerve regeneration as
determined by myelinated axon counts and electrophysiologic studies. Also, the
specific orientation of the sciatic nerve with respect to the magnetic field has
no influence on axonal growth or nerve conduction. Periods of restraint of 12
hours per day for 4 weeks significantly inhibit weight gain but have no effect
on peripheral nerve regeneration.
PMID: 2911629 [PubMed - indexed for MEDLINE]
8: Plast Reconstr Surg. 1991 Jan;87(1):122-9.
A multivariate approach to the treatment of peripheral nerve transection injury:
the role of electromagnetic field therapy.
Zienowicz RJ, Thomas BA, Kurtz WH, Orgel MG.
University of Massachusetts Medical School, Berkshire Medical Center,
Pittsfield.
A multivariate approach to the treatment of peripheral nerve transection injury
has been used in a rat model. A pilot study (48 animals, 8 groups) examined
variables associated with the method and timing of surgical repair, the arrest
of wallerian degeneration, and the role of pulsing electromagnetic field therapy
(PEMF) in functional recovery. A second phase (90 animals, 6 groups) then
studied the timing and duration of pulsing electromagnetic field therapy as the
only variable in larger groups of animals. The pilot study revealed that a
vein-graft conduit did not improve functional recovery compared with standard
epineurial repair. Additionally, delayed repair compared favorably with
immediate repair. The use of chlorpromazine to inhibit the toxic effects of
calcium influx appeared to enhance early functional recovery, and the
combination of delayed nerve repair and pulsing electromagnetic field therapy
seemed to consistently improve function. The second phase of the study has
demonstrated (for the first time) statistical improvement in ambulation in
animals treated with delayed surgical repair and prolonged pulsing
electromagnetic field therapy. We postulate that future treatment of nerve
transection injuries will involve a combined treatment regimen consisting of the
immediate arrest of wallerian degeneration, delayed surgery, and pulsing
electromagnetic field therapy.
PMID: 1984256 [PubMed - indexed for MEDLINE]
9: Lancet. 1982 Aug 21;2(8295):444-5.
Effects of high peak pulsed electromagnetic fields on degeneration and
regeneration of the common peroneal nerve in rate.
Raji AR, Bowden RE.
Publication Types:
Letter
PMID: 6124837 [PubMed - indexed for MEDLINE]
10: Equine Vet J. 1983 Oct;15(4):354-60.
Review of pulsing electromagnetic field therapy and its possible application to
horses.
Auer JA, Burch GE, Hall P.
The relevant literature on electrostimulation in general, and pulsing
electromagnetic fields in particular, is reviewed. DC current influences cell
behaviour by affecting transmembrane ion transport, which is often under
enzymatic control. Pulsing electromagnetic fields influence cell functions
through adsorption of ions or dipole formation at the cell membrane. Invasive
and non-invasive DC current stimulation is compared to pulsing electromagnetic
fields. The mode of application of pulsing electromagnetic fields to the equine
limb and suggested treatment times are briefly discussed. Two case reports are
used to illustrate the effect of pulsing electromagnetic fields in equine
fracture treatment.
Publication Types:
Case Reports
PMID: 6641683 [PubMed - indexed for MEDLINE]
11: Bioelectromagnetics. 1993;14(4):353-9.
Pretreatment of rats with pulsed electromagnetic fields enhances regeneration
of
the sciatic nerve.
Kanje M, Rusovan A, Sisken B, Lundborg G.
Department of Animal Physiology, University of Lund, Sweden.
Regeneration of the sciatic nerve was studied in rats pretreated in a pulsed
electromagnetic field (PEMF). The rats were exposed between a pair of Helmholtz
coils at a pulse repetition rate of 2 pps at a field density of 60 or 300
microT. The PEMF treatment was then discontinued. After an interval of recovery,
regeneration of the sciatic nerve was initiated by a crush lesion. Regeneration
of sensory fibers was measured by the "pinch test" after an additional 3-6 days.
A variety of PEMF pretreatments including 4 h/day for 1-4 days or exposure for
15 min/day during 2 days resulted in an increased regeneration distance,
measured 3 days after the crush lesion. This effect could be demonstrated even
after a 14-day recovery period. In contrast, pretreatment for 4 h/day for 2 days
at 60 microT did not affect the regeneration distance. The results showed that
PEMF pretreatment conditioned the rat sciatic nerve in a manner similar to that
which occurs after a crush lesion, which indicates that PEMF affects the
neuronal cell body. However, the mechanism of this effect remains obscure.
PMID: 8216387 [PubMed - indexed for MEDLINE]
12: Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 1999 Mar;13(2):114-8.
[Morphological changes and electrophysiological study of motor neuron of spinal
cord following delayed repair of peripheral nerve injury]
[Article in Chinese]
Zhu JY, Huang YT, Lu R.
Institute of Orthopaedics, Xijing Hospital, Fourth Military Medical University,
Xi'an Shanxi, P. R. China 710032.
OBJECTIVE: Following the delayed repair of peripheral nerve injury, the cell
number of anterior horn of the spinal cord and its ultrastructural changes,
motorneuron and its electrophysiological changes were investigated. METHODS: In
16 rabbits the common peroneal nerves of both sides being transected one year
later were divided into four groups randomly: the degeneration group and
regeneration of 1, 3 and 5 months groups. Another 4 rabbits were used for
control. All transected common peroneal nerves underwent epineural suture except
for the degeneration group the electrophysiological examination was carried out
at 1, 3 and 5 months postoperatively. Retrograde labelling of the anterior horn
cells was demonstrated and the cells were observed under light and
electronmicroscope. RESULTS: 1. The number of labelled anterior horn cell in the
spinal cord was 45% of the normal population after denervation for one year (P
<
0.01). The number of labelled cells increased steadily from 48% to 57% and 68%
of normal values at 1, 3 and 5 months following delayed nerve repair (P < 0.01).
2. The ultrastructure of the anterior horn cells of the recover gradually after
repair. 3. With the progress of regeneration the latency become shortened, the
conduction velocity was increased, the amplitude of action potential was
increased. CONCLUSION: Following delayed repair of injury of peripheral nerve,
the morphology of anterior horn cells of spinal cord and electrophysiological
display all revealed evidence of regeneration, thus the late repair of injury
of
peripheral nerve was valid.
PMID: 12080765 [PubMed - indexed for MEDLINE]
13: ASAIO Trans. 1988 Oct-Dec;34(4):947-51.
The use of DC electric fields to promote regeneration in the mammalian nervous
system.
Zanakis MF.
American Biointerface Corporation, New York, New York.
Publication Types:
Review
Review, Tutorial
PMID: 3064792 [PubMed - indexed for MEDLINE]
14: J UOEH. 1988 Mar 1;10(1):31-45.
The effect of long-term pulsing electromagnetic field stimulation on
experimental osteoporosis of rats.
Mishima S.
Department of Orthopedic Surgery, School of Medicine, University of Occupational
and Environmental Health, Kitakyushu, Japan.
The author performed experiments in order to investigate what biological effect
on the bone would be produced by long-term pulsing electromagnetic field (PEMF)
systemic stimulation. In some of the mature female rats used as experimental
animals, bilateral ovariectomy and right sciatic neurectomy were performed in
order to make a model osteoporosis. PEMF stimulation was produced by repetitive
pulse burst (RPB) waves at a positive amplitude of 25 mV, negative amplitude of
62.5 mV, burst width of 4.2 ms, pulse width of 230 microseconds and 12 Hz, with
the magnetic field strength within a cage being set at 3-10 Gauss. PEMF
stimulation over 6 months did not produce any effects on the physiologically
aged bones. PEMF stimulation also did not produce any effects on losed cortical
bone in osteoporotic hindlegs. On the other hand, an increase of bone volume and
bone formation activity was observed in the cancellous bone of osteoporotic
hindlegs. These findings suggested that PEMF stimulation exerted a preventive
effect against bone loss of osteoporotic hindlegs. Furthermore, an observed
increase in bone marrow blood flow seemed to be related with this increase of
bone volume and bone formation activity.
Publication Types:
Review
Review, Tutorial
PMID: 3285429 [PubMed - indexed for MEDLINE]
15: Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 1997 Jan;11(1):14-8.
[Influence of low energy He-Ne laser on regeneration of peripheral nerve]
[Article in Chinese]
Shi K, Lu R, Xu X.
Institute of Orthopedics of PLA, Fourth Military Medical University, Xi'an.
The purpose of this experiment was to elucidate the influence of the low-energy
He-Ne laser on the function of regeneration of peripheral nerve. Forty-four
rabbits about 2.5 kg body weight were used in the experiment. The animals were
divided into 4, 8, 12, 16 weeks groups according to the observation period. Six
animals were used in each irradiated group and in the control group 5 rabbits
were used in each observation period. Regeneration of the axon and myelinc
sheath, the latent rate of the common peroneal nerve, the conditions of the
anterior tibital muscle and the toe expansion test were all observed
systematically in both groups. The experimental results was: A few thin
regenerated axon was seen at 4 weeks in the irradiated group, while in the
control group it might be seen at 8 weeks, the P value was < 0.01. A low
amplitude latent rate of the common peroneal nerve is determined at the peroneal
side of the anterior tibial muscle in a few animal at 4 weeks of the irradiated
group, and it is not observed in the control group, from 12 to 16 weeks. THe
latent rate of the common peroneal nerve was the irradiated group than in the
controlled, the P value was < 0.01. The regeneration of the myeline sheath
was
evident in the irradiated group, and also the slstion of the musdle fibers
anterior tibial muscle was clearly visible than the controlled. 16 weeks
postoperatively, the toe expansion test was normal in the irradiated group,
while in the control group it was the same as seen at 12 weeks after operation
in the irradiated group. Now it was certain that the low-energy He-Ne laser
could promole the function of the spinal motor nerve cells and accelerate the
axonal regeneration.
PMID: 9867943 [PubMed - indexed for MEDLINE]
16: Clin Orthop. 1983 Dec;(181):277-82.
Effects of pulsing electromagnetic fields on bone growth and articular
cartilage.
Smith RL, Nagel DA.
Observations made during treatment of juvenile pseudarthrosis by pulsing
electromagnetic fields (PEMF) suggested that bone growth might be altered. PEMF
applied to immature rabbits under conditions of continuous stimulation (24
hours/day for 8 weeks) produced no major changes in bone growth. Continuous
stimulation by PEMF induced a statistically significant increase (22%) in
femoral articular cartilage glycosaminoglycan. Intermittent PEMF stimulation (12
hours with stimulation/12 hours without stimulation) for 18 weeks produced no
significant change in bone growth or time of epiphyseal plate closure. No
significant changes in the physical characteristics of growing bone were
observed with any treatment.
PMID: 6641061 [PubMed - indexed for MEDLINE]
17: J Reconstr Microsurg. 1999 Aug;15(6):427-31.
Using a direct current electrical field to promote spinal-cord regeneration.
Shen NJ, Wang SC.
Department of Orthopedics, People's Hospital of Hainan Province, Haikou, China.
The authors used a direct current electrical field to promote spinal-cord
regeneration in a canine model. Thirty-two dogs were randomly divided into four
groups. Complete spinal-cord injury was induced, and electrical stimulators were
then placed in the animals. Group 1 served as controls; Groups 2 to 4 were
experimental groups, with varying stimulator voltages: 0V in Group 1, 12V in
Groups 2 and 4, and 6V in Group 3, with the stimulator implanted 6 hr after
spinal-cord injury in Group 4. Functional, electrophysiologic and morphometric
assessments were carried out 1 to 3 months postoperatively. Results showed that
spinal-cord function, cortical somatosensory evoked potentials, number of
neurons, sectional area of neurons, and Nissl body density in the experimental
groups were much better than those in the control group. In addition, all the
indices in Group 2 were better than those in Groups 3 and 4. This indicated that
direct current electrical stimulation could effectively promote spinal-cord
regeneration and functional recovery in this model. The 12V voltage was safe for
the animals. The stimulator was not rejected by the host for a relatively long
period of time.
PMID: 10480562 [PubMed - indexed for MEDLINE]
18: Brain Res. 1985 Nov 25;348(1):159-62.
Regeneration of gamma-fusimotor axons after nerve-freeze injury in the cat.
Scott JJ.
Nerve injury was produced by application of dry ice to the common peroneal
nerve. After 20 weeks, muscle-spindle primary endings responded normally to
stretch and the spindles were found to have a fully functional fusimotor
innervation.
PMID: 4063820 [PubMed - indexed for MEDLINE]
19: Muscle Nerve. 2001 May;24(5):662-6.
Partial peripheral motor nerve lesions induce changes in the conduction
properties of remaining intact motoneurons.
Havton LA, Hotson JR, Kellerth JO.
Department of Neurology, University of California, Los Angeles, and Reed
Neurological Research Center, 710 Westwood Plaza, Los Angeles, California
90095-1769, USA. LHavton@mednet.ucla.edu
A partial injury or loss of peripheral motor axons is followed by compensatory
sprouting of remaining intact motor axons in order to reinnervate muscle. Little
is known, however, about the electrophysiologic properties proximally of these
intact motoneurons and their axons following injury of neighboring motor axons.
We studied the conduction properties of intact cat motor axons and motoneurons
proximal to the site of a partial peripheral nerve section. Twelve weeks after
the partial transection of the cat medial gastrocnemius motor nerve, there was
a
significant (7%) reduction in conduction velocity and a 13% prolongation in
afterhyperpolarization half-decay time in the remaining intact motoneurons,
compared with controls. Partial injury to motor nerves thus induces reactive
electrophysiologic changes in the remaining intact motoneurons and their axons,
perhaps associated with compensatory sprouting within partially denervated
muscle. Copyright 2001 John Wiley & Sons, Inc.
PMID: 11317276 [PubMed - indexed for MEDLINE]
20: J Hand Surg [Am]. 1983 May;8(3):248-53.
Specificity of muscle reinnervation after epineurial and individual fascicular
suture of the rat sciatic nerve.
Brushart TM, Tarlov EC, Mesulam MM.
We experimentally analyzed the specificity of muscle reinnervation after suture
and regeneration of rat sciatic nerve. We used a horseradish peroxidase (HRP)
technique of axon tracing to compare the number and location of motoneurons that
innervate muscle via the peroneal nerve after epineurial and individual
fascicular suture of the parent sciatic nerve. These motoneurons are
significantly reduced in number from control levels and are often in spinal cord
locations that indicate previous innervation of antagonistic muscle via the
tibial nerve. This inappropriate reinnervation of peroneal muscle by tibial
motoneurons is minimized by individual fascicular suture without compromise of
overall reinnervation. Our findings thus support the hypothesis that individual
fascicular suture may avoid distortion of the central connections of peripheral
units.
PMID: 6348148 [PubMed - indexed for MEDLINE]
21: Science. 1980 May 9;208(4444):603-5.
Alteration in connections between muscle and anterior horn motoneurons after
peripheral nerve repair.
Brushart TM, Mesulam MM.
The connections between the spinal cord and lower leg muscles of the rat are
significantly altered by repair of the intervening sciatric nerve. Muscles
supplied by the peroneal branch of the sciatic are innervated by fewer
motoneurons after sciatic repair. Many of these neurons originally innervated
the peroneal muscles, and others formerly served the antagonistic tibial
muscles. Perikarya in the size range of alpha motoneurons regained peripheral
connections with greater frequency than those in the gamma range. There are thus
postoperative defects in the extent and specificity of alpha reinnervation as
well as in the degree of gamma control.
PMID: 7367884 [PubMed - indexed for MEDLINE]
22: Spine. 1984 Apr;9(3):273-9.
The effect of postoperative electromagnetic pulsing on canine posterior spinal
fusions.
Kahanovitz N, Arnoczky SP, Hulse D, Shires PK.
An experimental canine study was devised to evaluate the efficacy of a
noninvasive adjunct to improve the rate and quality of the posterior fusion mass
over the standard surgical technique. Ten large adult mongrel dogs underwent a
three-level lumbar spinal fusion. Bone excised from the spinous processes was
packed in removed facet joints and over the decorticated laminae. To insure
rigid internal fixation, custom-made distraction instrumentation was placed
bilaterally under the laminae of the vertebrae above and below the three fused
vertebrae. Five dogs underwent electromagnetic pulsing, and five dogs acted as
controls. Two dogs were sacrificed at 4, 6, 9, 12, and 15 weeks to assess the
radiographic and histologic status of the fusion mass. Preoperative and
preautopsy hematologic studies as well as gross and histologic autopsy specimens
revealed no abnormalities attributable to the electromagnetic pulsing.
High-resolution radiography and histologic studies showed earlier incorporation
of the graft, improved new bone formation, and better organization of the fusion
mass in the 4-, 6-, and 9-week stimulated specimens. However, by 12 and 15 weeks
there did not appear to be any histologic or radiographic differences between
the stimulated and control dogs. Although electromagnetic pulsing appears to
produce an early accelerated osteogenic response, it does not appear to improve
the overall results of primary canine spinal fusions.
PMID: 6729593 [PubMed - indexed for MEDLINE]
23: Exp Neurol. 1983 May;80(2):418-26.
Reinnervation of the gastrocnemius muscle by the contralateral S1 nerve root.
Shonnard N, Wakefield C.
Functional regeneration after transposition of a ventral nerve root was
established in the adult cat. Reconstruction of the ventral root, using
microsurgical methods, directed the right S1 ventral nerve root to innervate the
left gastrocnemius muscle. Stimulus-induced unit responses were recorded from
the left gastrocnemius muscle 5 to 8 months after the root cross, demonstrating
the reestablishment of neuromuscular connections. The innervation of the left
gastrocnemius muscle by neurons in the right ventral horn of the spinal cord was
verified by injecting horseradish peroxidase into the muscle. Horseradish
peroxidase reaction product was located in alpha and gamma motor neurons in the
right S1 segment of the spinal cord. Computer-assisted determination of the soma
area of the labeled neurons was compared with a normal S1 innervation of the
gastrocnemius muscle. Analysis of the percentage of cells of a given soma area
demonstrated an overall decrease in soma area in the operated animals. Because
ventral root reconstruction can result in innervation of a foreign muscle,
studies such as this may encourage repair or reconstruction of nerve roots to
gain some functional recovery after spinal cord or nerve root injuries.
PMID: 6840247 [PubMed - indexed for MEDLINE]
24: Bioelectromagnetics. 1996;17(1):44-7.
Effect of low-intensity millimeter wave electromagnetic radiation on
regeneration of the sciatic nerve in rats.
Kolosova LI, Akoev GN, Avelev VD, Riabchikova OV, Babu KS.
Pavlov Institute of Physiology, Russian Academy of Sciences, St. Petersburg.
The effect of low-intensity millimeter wave electromagnetic radiation (MWR) on
regeneration of the rat sciatic nerve after transection and microsurgical
reapproximation was examined. Rats were exposed to 54 GHz MWR at a power density
of 4 mW/cm2. It was found that MWR treatment of the femoral skin in the area of
suture accelerated the regeneration of nerve fibers. At the twentieth
postoperative day, the MWR-treated animals had a 32% increase in the
regeneration distance compared to the control animals. The conduction velocity
showed a 26% increase in the MWR-treated animals.
PMID: 8742755 [PubMed - indexed for MEDLINE]
25: J Neurosci Res. 1995 Dec;42(5):692-9.
Acute treatment with pulsed electromagnetic fields and its effect on fast axonal
transport in normal and regenerating nerve.
Sisken BF, Jacob JM, Walker JL.
Department of Anatomy and Neurobiology, University of Kentucky, Lexington 40506,
USA.
The mechanism whereby low-frequency electromagnetic fields accelerate axonal
regrowth and regeneration of peripheral nerve after crush lesion is not known.
One candidate is an alteration in axonal transport. In this study we exposed
unoperated rats for 15 min/day, and rats that had undergone a crush lesion of
the sciatic nerve, for 1 hr/day for 2 days, to 2-Hz pulsed electromagnetic
fields. To label fast transported proteins, [3H]-proline was microinjected into
the spinal cord, and the sciatic nerves were removed 2, 3.5, and 5 hr later. The
rates of fast axonal transport were obtained for animals in all groups by
counting sequential 2-mm segments of nerves. The following transport rates were
found: in unoperated normal sciatic nerve not exposed to PEMF, 373 +/- 14
mm/day; in unoperated normal nerve exposed to PEMF, 383 +/- 14 mm/day; in sham
crush nerves not exposed to PEMF, 379 +/- 19 mm/day; in sham crush nerve exposed
to PEMF, 385 +/- 17 mm/day; in crushed nerves not exposed to PEMF, 393 +/- 16
mm/day. and in crushed nerves exposed to PEMF, 392 +/- 15 mm/day. The results
of
these experiments indicate that 1) a crush injury to the sciatic nerve does not
alter the rate of fast axonal transport, and 2) low-frequency pulsed
electromagnetic fields do not alter fast axonal transport rates in operated
(crush) or unoperated sciatic nerves.
PMID: 8600302 [PubMed - indexed for MEDLINE]
26: Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 1997 Jan;11(1):10-3.
[Influence of low energy He-Ne laser on spinal motor nerve cell]
[Article in Chinese]
Shi K, Lu R, Xu X.
Institute of Orthopedics of PLA, Fourth Military Medical University, Xi'an.
The object of this experimental study was to investigate the influence of
low-energy He-Ne laser on the motor nerve cells of the spinal cord. The
experimental study included as follws: (1) Four rabbits were used in this
experiment. The L5-6 spinal cord segment was irradiated by He-Ne laser
percutaneously, the nerve velocity of the comon peroneal nerve was measured in
order to determine the function of the spinal motor nerve cells when the
peripheral nerve was intact. (2) The common peroneal nerve was transected on one
side wothout repair, two weeks after laser irradiation, the grey mater of the
spinal cord of L5-6 segment was procured for electronic microscopic examination.
(3) The common peroneal nerve on the contralateral side was transected and
followed by end-to-end anastomosis, and laser irradiation was done on the same
spinal cord segment. Two weeks after irradiation, the nerve velocity of the
common peroneal nerve and the toe expanding test were investigated. The results
were: (1) the He-Ne laser can influence the spinal motor nerve cells function
as
expressed by latent rate when the peripherial nerve is intact. i.e. the nerve
velocity is slower than mormal, and the amplitude is markedly decreared. (2) the
change of the microstructure of the spinal motor nerve cells is comparatively
slight in the 10 and 15 minutes groups. (3) the recovery of the nerve velocity
and the toe expansion are more earlier in the 15 min. group. In short, the
low-energy He-Ne laser can influence the function of the spinal motor nerve
cells.
PMID: 9867942 [PubMed - indexed for MEDLINE]
27: J Bone Joint Surg Am. 1982 Jul;64(6):888-95.
Modification of fracture repair with selected pulsing electromagnetic fields.
Bassett CA, Valdes MG, Hernandez E.
We assayed different pulsing electromagnetic fields for their effects on the
mechanical and histological repair properties of an osteotomy of the radius of
the rat fourteen days postoperatively. Highly significant differences were found
in the control and experimental initial load values and their decay as a
function of time. These results correlate well with the histological pattern in
the bridging callus. A pulse that produces an increase (above the control level)
in initial load by a factor of 2.4 and a slower decay was characterized by more
extensive calcification of fibrocartilage and its replacement by fibrous bone
at
this early, but important, stage in fracture-healing.
PMID: 7085716 [PubMed - indexed for MEDLINE]
28: J Neurosurg. 1995 Apr;82(4):623-9.
The fate of motoneurons in the spinal cord after peripheral nerve repair: a
quantitative study using the neural tracer horseradish peroxidase.
Gilmour JA, Myles LM, Glasby MA.
Department of Anatomy, University of Edinburgh, Medical School, Scotland.
This study assessed the changes that occurred in the spinal motoneuron pool
after the repair of a specific peripheral nerve by means of several clinically
appropriate surgical techniques: nerve graft, muscle graft, and epineurial
suture. The motoneuron pool relating to a single muscle was assessed at 50, 100,
200, and 300 days after repair via retrograde axonal transport of the neural
tracer horseradish peroxidase. The results indicate that although a small
portion of the motoneuron population dies following peripheral nerve surgery,
this is not a significant number. The majority of the anterior horn cells appear
to have the ability to both survive nerve transection and form new functional
connections with the regenerated nerve after repair. The degree of cell loss is
influenced by the nature of the injury and the method of repair implemented.
Injuries involving neurotmesis result in the loss of a greater proportion of the
cell population than less severe injuries involving axonotmesis. A greater
proportion of the motoneuron population is preserved when the severed nerve has
been repaired using a direct epineurial suture than when repair is achieved by
means of a graft. The two methods of grafting produced comparable results,
although the muscle graft tended to result in the preservation of a greater
number of cells than the nerve graft, making it an acceptable alternative method
for the surgical repair of short gaps in peripheral nerves.
PMID: 7897525 [PubMed - indexed for MEDLINE]
29: Exp Mol Med. 2002 Mar 31;34(1):53-9.
Enhanced expression of neuronal nitric oxide synthase and phospholipase C-gamma1
in regenerating murine neuronal cells by pulsed electromagnetic field.
Kim SS, Shin HJ, Eom DW, Huh JR, Woo Y, Kim H, Ryu SH, Suh PG, Kim MJ, Kim JY,
Koo TW, Cho YH, Chung SM.
Department of Pathology, Ulsan University College of Medicine, Korea.
Pulsed electromagnetic field (PEMF) has been shown to improve the rate of
peripheral nerve regeneration. In the present study we investigated the
expression of neuronal nitric oxide synthase (nNOS) and phospholipase C-gamma1
(PLC-gamma1) in regenerating rat laryngeal nerves during the exposure to PEMF
after surgical transection and reanastomosis. Axons were found to regenerate
into the distal stump nearly twice faster in PEMF-exposed animals than in the
control. Consistently, motor function was better recovered in PEMF-treated rats.
The expression of nNOS and PLC-gamma1 was highly enhanced in the regenerated
nerves.
PMID: 11989979 [PubMed - indexed for MEDLINE]
30: Spine. 2003 Dec 15;28(24):2660-6.
Exposure to pulsed magnetic fields enhances motor recovery in cats after spinal
cord injury.
Crowe MJ, Sun ZP, Battocletti JH, Macias MY, Pintar FA, Maiman DJ.
Neuroscience Research Laboratories, The Clement J. Zablocki VA Medical Center,
Milwaukee, WI 53295, USA. mcrowe@mcw.edu
STUDY DESIGN: Animal model study of eight healthy commercial cats was conducted.
OBJECTIVE: To determine whether pulsed electromagnetic field (PMF) stimulation
results in improvement of function after contusive spinal cord injury in cats.
SUMMARY OF BACKGROUND DATA: PMF stimulation has been shown to enhance nerve
growth, regeneration, and functional recovery of peripheral nerves. Little
research has been performed examining the effects of PMF stimulation on the
central nervous system and no studies of PMF effects on in vivo spinal cord
injury (SCI) models have been reported. MATERIALS AND METHODS: PMF stimulation
was noninvasively applied for up to 12 weeks to the midthoracic spine of cats
with acute contusive spinal cord injury. The injury was produced using a
weight-drop apparatus. Motor functions were evaluated with the modified Tarlov
assessment scale. Morphologic analyses of the injury sites and
somatosensory-evoked potential measurements were conducted to compare results
between PMF-stimulated and control groups. RESULTS: There was a significant
difference in locomotor recovery between the PMF-stimulated and control groups.
Although not statistically significant, PMF-stimulated spinal cords demonstrated
greater sparing of peripheral white matter and smaller lesion volumes compared
to controls. Somatosensory-evoked potential measurements indicated that the
PMF-stimulated group had better recovery of preinjury waveforms than the control
group; however, this observation also was not statistically significant because
of the small sample size. CONCLUSIONS: This preliminary study indicates that
pulsed magnetic fields may have beneficial effects on motor function recovery
and lesion volume size after acute spinal cord injury.
PMID: 14673366 [PubMed - in process]
31: Exp Neurol. 1994 Feb;125(2):302-5.
Enhancement of functional recovery following a crush lesion to the rat sciatic
nerve by exposure to pulsed electromagnetic fields.
Walker JL, Evans JM, Resig P, Guarnieri S, Meade P, Sisken BS.
Division of Orthopaedic Surgery, University of Kentucky College of Medicine,
Shriners Hospitals for Crippled Children, Lexington.
Previous studies showed that exposure to pulsed electromagnetic fields (PEMF)
produced a 22% increase in the axonal regeneration rate during the first 6 days
after crush injury in the rat sciatic nerve. We used the same injury model to
assess the effect on functional recovery. The animals were treated with whole
body exposure to PEMF (0.3 mT, repetition rate 2 Hz) for 4 h/day during Days 1-5
while held in plastic restrainers. Functional recovery was serially assessed up
to Postinjury Day 43 using recently described video imaging of the 1-5 toe
spread and the gait-stance duration. Footprint analysis was also used with
calculation of a sciatic function index. Those animals treated with PEMF had
improved functional recovery, as compared to sham controls, using the tests for
video 1-5 toe spread and gait-stance duration (P = 0.001 and P = 0.081,
respectively). This effect was found throughout the 43-day recovery period. No
effect was found using the sciatic function index. This study confirms that
functional recovery after nerve crush lesion is accelerated by PEMF and has
broad implications for the clinical use of these fields in the management of
nerve injuries.
PMID: 8313945 [PubMed - indexed for MEDLINE]
32: J Neurosurg. 1996 Feb;84(2):234-43.
Reinnervation of avulsed and reimplanted ventral rootlets in the cervical spinal
cord of the cat.
Hoffmann CF, Marani E, van Dijk JG, vd Kamp W, Thomeer RT.
Department of Neurosurgery, University of Leiden, The Netherlands.
Spinal nerve root avulsions frequently occur in brachial plexus injuries caused
by traction. Such lesions are considered to afflict the central nervous system
(CNS) and are, therefore, believed to be beyond surgical repair. The present
experimental study was initiated to challenge this hypothesis. The ventral
rootlets of C-7 were avulsed from the spinal cord in 28 cats via an anterior
approach and subsequently reimplanted into the cord at the site of origin. In
nonoperated control cats and cats undergoing reimplantation,
electrophysiological experiments were performed and horseradish peroxidase was
administered to the spinal nerve on the reimplanted side after survival times
ranging from 6 to 293 days. Spinal cord sections in all cats were stained for
neurofilament, acetylcholinesterase (AChE), Nissl, and glial fibrillary acidic
protein. Horseradish peroxidase-labeled ventral horn motoneurons were found as
early as 14 days after reimplantation and their number increased with time. On
Days 209 and 293, the number of labeled neurons equaled the number of labeled
ventral horn neurons in the two control cats that did not undergo surgery.
Starting on Day 6 after reimplantation, the appearance of the ventral horn and
the white matter in the neurofilament, AChE, and Nissl-stained sections changed
as a result of the CNS response to the injury. A return to their normal
appearance could be observed in these stainings from Day 209 onward. Glial
fibrillary acidic protein-positive astrocytic tissue was consistently found in
the ventral horn and in the white matter reimplantation area. From Day 69
onward, electrophysiological stimulation of the spinal nerve C-7 on the
reimplanted side elicited an electromyogram response in the spinodeltoid muscle.
The latency and threshold intensity of the C-7 responses were initially
increased but equalized to match the nonoperated controls between 98 and 122
days after reimplantation. The results of this study show that functional
regeneration of ventral horn neurons after root avulsion and subsequent
reimplantation in the cat is possible.
PMID: 8592226 [PubMed - indexed for MEDLINE]
33: Lancet. 1984 Mar 31;1(8379):695-8.
Pulsed electromagnetic field therapy of persistent rotator cuff tendinitis. A
double-blind controlled assessment.
Binder A, Parr G, Hazleman B, Fitton-Jackson S.
The value of pulsed electromagnetic fields (PEMF) for the treatment of
persistent rotator cuff tendinitis was tested in a double-blind controlled study
in 29 patients whose symptoms were refractory to steroid injection and other
conventional conservative measures. The treated group (15 patients) had a
significant benefit compared with the control group (14 patients) during the
first 4 weeks of the study, when the control group received a placebo. In the
second 4 weeks, when all patients were on active coils, no significant
differences were noted between the groups. This lack of difference persisted
over the third phase, when neither group received any treatment for 8 weeks. At
the end of the study 19 (65%) of the 29 patients were symptomless and 5 others
much improved. PEMF therapy may thus be useful in the treatment of severe and
persistent rotator cuff and possibly other chronic tendon lesions.
Publication Types:
Clinical Trial
Randomized Controlled Trial
PMID: 6143039 [PubMed - indexed for MEDLINE]
34: J Bone Joint Surg Am. 1982 Oct;64(8):1214-20.
Treatment of therapeutically resistant non-unions with bone grafts and pulsing
electromagnetic fields.
Bassett CA, Mitchell SN, Schink MM.
This study reviews the cases of eighty-three adults with ununited fractures who
were treated concomitantly with bone-grafting and pulsed electromagnetic fields.
An average of 1.5 years had elapsed since fracture and the use of this combined
approach. Nearly one-third of the patients had a history of infection, and an
average of 2.4 prior operations had failed to produce bone union. Thirty-eight
patients who were initially treated with grafts and pulsed electromagnetic
fields for ununited fractures with wide gaps, synovial pseudarthrosis, and
malalignment achieved a rate of successful healing of 87 per cent. Forty-five
patients who had initially been treated unsuccessfully with pulsing
electromagnetic fields alone had bone-grafting and were re-treated with pulsing
electromagnetic fields. Ninety-three per cent of these fractures healed. The
residual failure rate after two therapeutic attempts, one of which was
operative, was 1.5 per cent. The median time to union for both groups of
patients was four months.
PMID: 6752151 [PubMed - indexed for MEDLINE]
35: Prog Clin Biol Res. 1986;210:251-60.
Effects of applied DC fields on sensory nerve sprouting and motor-nerve
regeneration in adult rats.
Pomeranz B.
PMID: 3960914 [PubMed - indexed for MEDLINE]
36: JAMA. 1982 Aug 27;248(8):921.
Pulsing electromagnetic field treatment.
Irvine RD.
Publication Types:
Letter
PMID: 7097952 [PubMed - indexed for MEDLINE]
37: Clin Exp Rheumatol. 1985 Oct-Dec;3(4):333-6.
Chronic lateral humeral epicondylitis--a double-blind controlled assessment of
pulsed electromagnetic field therapy.
Devereaux MD, Hazleman BL, Thomas PP.
Pulsed electromagnetic fields (PEMF) have been shown to be beneficial in the
treatment of rotator cuff tendinitis. As lateral humeral epicondylitis (tennis
elbow) is a similar chronic tendon lesion, 30 patients with both clinical and
thermographic evidence of tennis elbow were randomly allocated to receive either
active or inactive PEMF therapy. Treatment was continued for a minimum period
of
eight weeks. At this time there was no statistical difference between the two
groups.
Publication Types:
Clinical Trial
Randomized Controlled Trial
PMID: 4085165 [PubMed - indexed for MEDLINE]
38: Electromyogr Clin Neurophysiol. 1994 Jul-Aug;34(5):259-64.
Electrophysiological study of regenerated rabbit tibial and peroneal nerves:
autologous versus non-neural grafts.
Wessel K, Muller H, Deseniss V, Dombert T.
Department of Neurology, Medical University of Lubeck, Germany.
In recent years, successful experimental nerve regeneration using extracellular
matrix as implants has been reported. In the present study, we compared
peripheral nerve regeneration through implants of amnion membrane matrix (AMM)
and umbilical cord membrane matrix (UCMM) versus autologous nerve
transplantation, bridging gaps 8-12 mm in length in rabbit tibial and peroneal
nerves. The data are based on direct nerve stimulation and recording of
somatosensory evoked potentials (SEPs) and muscle action potentials (MAPs) to
measure functional recovery after these different types of neuroplastic
bridging. Incomplete regeneration was demonstrable as missing SEPs (15-22%),
missing MAPs (17-42%), a mean delay of SEPs and distal motor latencies of
approximately 40-50% compared with a normal control group, and slowed motor
conduction velocities by approximately 50%. There were no significant
differences between the three different types of neuroplastic bridging. Most of
the AMM and UCMM implants (80-100%), but none of the autologous nerve
transplants, caused inadequate connections with peripheral targets. We conclude
that extracellular matrix implantation represents a useful experimental model
for studying the biological basis of nerve regeneration, but does not yet serve
as a tool for therapeutic applications.
PMID: 7956874 [PubMed - indexed for MEDLINE]
39: J Neurosurg. 2001 Jan;94(1 Suppl):82-90.
Innervation of the caudal denervated ventral roots and their target muscles by
the rostral spinal motoneurons after implanting a nerve autograft in spinal
cord-injured adult marmosets.
Liu S, Aghakhani N, Boisset N, Said G, Tadie M.
Laboratory of Experimental Neurosurgery, Faculte de M ecine Paris-Sud,
University of Paris XI, France.
OBJECT: The authors conducted a study to determine the effects of using a nerve
autograft (NAG) to promote and guide axonal regrowth from the rostral spinal
cord to the caudal lumbar ventral nerve roots to restore hindlimb motor function
in adult marmosets after lower thoracic cord injury. METHODS: Nine animals
underwent a left-sided hemisection of the spinal cord at T-12 via left-sided
T9-L3 hemilaminectomy, with section of all ipsilateral lumbrosacral ventral
nerve roots. In the experimental group (five animals), an NAG obtained from the
right peroneal nerve was anastomosed with the sectioned and
electrophysiologically selected lumbar ventral roots (left L-3 and L-4)
controlling the left quadriceps muscle and then implanted into the left
ventrolateral T-10 cord. In the control group (four animals), the
sectioned/selected lumbar ventral roots were only ligated. After surgery, all
marmosets immediately suffered from complete paralysis of their left hindlimb.
Five months later, some clinical signs of reinnervation such as tension and
resistance began to appear in the paralyzed quadriceps of all experimental
animals that received autografts. Nine months postoperatively, three of the five
experimental marmosets could maintain their lesioned hindlimb in hip flexion.
Muscle action potentials and motor evoked potentials were recorded from the
target quadriceps in all experimental marmosets, but these potentials were
absent in the control animals. Horseradish peroxidase retrograde labeling from
the distal sectioned/reconnected lumbar ventral roots traced 234+/-178 labeled
neurons in the ipsilateral T8-10 ventral horn, mainly close to the NAG tip.
Histological analysis showed numerous regenerating axons in this
denervated/reconnected nerve root pathway, as well as newly formed motor
endplates in the denervated/reinnervated quadriceps. No axonal regeneration was
detected in the control animals. CONCLUSIONS: These data indicate that the
rostral spinal neurons can regrow into the caudal ventral roots through an NAG,
thereby innervating the target muscle in adult marmosets after spinal cord
injury.
PMID: 11147873 [PubMed - indexed for MEDLINE]
40: Exp Neurol. 1998 Jul;152(1):95-100.
Motoneuron survival after neonatal peroneal nerve injury in the rat-evidence for
the sparing effect of reciprocal inhibition.
Waters HJ, Barnett G, O'Hanlon GM, Lowrie MB.
Division of Biomedical Sciences, Imperial College School of Medicine, Norfolk
Place, London, W2 1PG, United Kingdom.
Sciatic nerve crush at birth results in the death of most of the motoneurons in
the sciatic motor pool. It has been proposed that these cells die through
excessive activation which can be explained partly by an increased
susceptibility to NMDA. However, it is also possible that decreased inhibitory
mechanisms resulting from nerve injury may contribute to overactivation of the
motoneurons. In this study we compared the survival of motoneurons innervating
two muscles in the peroneal motor pool, tibialis anterior and extensor digitorum
longus, after either sciatic or common peroneal nerve crush. These two
procedures both axotomize the motoneurons but differ in their effects on
afferent input. Sciatic nerve crush severely reduces the afferent input from the
antagonist muscles innervated via the tibial nerve, whereas common peroneal
nerve crush preserves them. Using retrograde labeling with horseradish
peroxidase, we found that almost twice as many motoneurons survived common
peroneal nerve crush than sciatic nerve crush and that muscle weight showed a
corresponding significant improvement. A control experiment excluded the
possible involvement of increased stretch of the muscles as a result of common
peroneal nerve crush alone as an explanation for the improvement. We therefore
suggest that the increased survival of motoneurons after peroneal nerve crush
was due to the preservation of their reciprocal inhibitory input. However, since
even with this improvement the majority of motoneurons still died, loss of
reciprocal inhibition probably does not play a major role in the death of
motoneurons induced by overactivation. Copyright 1998 Academic Press.
PMID: 9682016 [PubMed - indexed for MEDLINE]
41: Zh Nevropatol Psikhiatr Im S S Korsakova. 1989;89(5):41-4.
[Characteristics of the effect of a constant electromagnetic field on reparative
processes in spinal cord injuries]
[Article in Russian]
Tkach EV, Abilova AN, Gazalieva ShM.
In 171 white rats the spinal cord was completely sectioned in the upper thoracic
region. In 46 control rats an early crude spinal cord scar was identified which
precluded the growth of nervous fibers. On the contrary, in animals exposed to
constant magnetic field a smooth spinal cord scar was found with collaterals of
anterior spinal arteria, recrease of the destruction zone and nervous fiber
growth across the scar, This resulted in restored hind paw motility by 56 +/-
4.8% as related to control rats in which motility did not restore. Magnet
therapy applied as a part in combined restitutional therapy in 104 patients in
early restitution period yielded a 46.15 +/- 4.89% to 76.32 +/- 4.87% increase
in the rate of restoration of motor and sensory functions. With the therapy
applied in late periods, the restitution was 48.1 +/- 5.6% and 78.1 +/- 3.9%,
respectively. The magnetic field is considered as a reparation booster in spinal
cord trauma applicable in any stage of the disease.
PMID: 2781918 [PubMed - indexed for MEDLINE]
42: Am J Otolaryngol. 1993 Jan-Feb;14(1):43-8.
Misdirected regeneration of injured recurrent laryngeal nerve in the cat.
Nahm I, Shin T, Watanabe H, Maeyama T.
Department of Otolaryngology, Saga Medical School, Japan.
INTRODUCTION: Misdirected regeneration (MR) frequently occurs following injury
to the recurrent laryngeal nerve (RLN) resulting in neurotmesis or axonotmesis.
Physiological and anatomic parameters involved in the functional recovery of the
larynx following freezing injury or neurorrhaphy of the RLN were studied. A
multi-facilitated approach is undertaken to clarify the functional abnormalities
caused by the MR after recurrent laryngeal nerve injury. MATERIALS AND METHODS:
Three groups of adult cats were studied. These included controls, cats with
recurrent laryngeal neurorrhaphy, and cats with recurrent laryngeal nerve freeze
injuries. From 2 weeks to 9 months after the nerve injury, the animals were
studied endoscopically and with electromyography (EMG). Using the same animal,
the number and location of motoneurons supplying the ipsilateral posterior
cricoarytenoid (PCA) muscle were examined with horseradish peroxidase (HRP).
Animals were subsequently sacrificed to study the pattern of reinnervation.
RESULTS: Following neurorrhaphy all cats had vocal cord paralysis. After
neurorrhaphy, effective motion function did not return in the affected vocal
cord and it remained fixed in the paramedian position. Although EMG of the
laryngeal muscles of the affected side showed interference voltage, the pattern
of activities was markedly different from that of the unaffected side, and
reciprocity among the laryngeal muscles was not restored. The number of PCA
motoneurons recovered to the normal range, but a considerable number of neuronal
bodies were dispersed outside the normal PCA area. This indicates misdirected
reinnervation to the PCA muscle by motoneurons that originally served other
laryngeal muscles. In the freezing injury, effective vocal cord movement finally
recovered after 6 months. At this time, EMG showed a normal pattern, although
a
relatively small amount of misdirected neurons was observed. DISCUSSION:
Functional recovery of vocal cord motion does not occur following neurorrhaphy.
Prominently disorganized arrangement of laryngeal motor neurons was observed in
the horseradish peroxidase study. This suggests that inappropriate reinnervation
develops in spite of reapproximation and suturing. Altered central organization
of the motor nucleus is a significant pathogenic factor in the loss of laryngeal
muscular coordination following recurrent laryngeal nerve lesions. The degree
of
recovery is related to the mechanism of injury.
PMID: 8434719 [PubMed - indexed for MEDLINE]
43: Arch Otolaryngol Head Neck Surg. 1998 Apr;124(4):383-9.
Effect of pulsed electromagnetic stimulation on facial nerve regeneration.
Byers JM, Clark KF, Thompson GC.
Department of Otorhinolaryngology, University of Oklahoma Health Sciences
Center, Oklahoma City, USA.
OBJECTIVE: To determine if exposure to electromagnetic fields influences
regeneration of the transected facial nerve in the rat. DESIGN AND METHODS: The
left facial nerve was transected in the tympanic section of the fallopian canal
in 24 rats randomly assigned to 2 groups. The cut ends of the facial nerve were
reapproximated without sutures within the fallopian canal to maximize the
potential for regeneration. Rats in the experimental group (n= 12) were then
exposed to pulsed electromagnetic stimulation (0.4 millitesla at 120 Hz) for 4
hours per day, 5 days per week, for 8 weeks. Rats in the control group (n=12)
were handled in an identical manner without pulsed electromagnetic stimulation.
Four other rats were given sham operations in which all surgical procedures were
carried out except for the actual nerve transection. Two of these rats were
placed in each group. Nerve regeneration was evaluated using electroneurography
(compound action potentials), force of whisker and eyelid movements, and
voluntary facial movements before and at 2-week intervals after transection.
Histological evaluation was performed at 10 weeks after transection. Each
dependent variable was analyzed using a 2-way analysis of variance with 1
between variable (groups) and 1 within repeated measures variable (days after
transection). RESULTS: Statistical analysis indicated that N1 (the negative
deflection of depolarization phase of the muscle and/or nerve fibers) area, N1
amplitude, and N1 duration, as well as absolute amplitude of the compound action
potentials, were all significantly greater 2 weeks after transection in the
experimental than in the control group of rats. The force of eye and whisker
movements after electrical stimulation was statistically greater in the
experimental group of rats 4 weeks after transection. Voluntary eye movements
in
the experimental group were significantly better at 5 and 10 weeks, while
whisker movements were better at 3 and 10 weeks. There was no statistical
difference between the 2 groups for any histological variable. CONCLUSION:
Results of this study indicate that pulsed electromagnetic stimulation enhances
early regeneration of the transected facial nerve in rats.
PMID: 9559684 [PubMed - indexed for MEDLINE]
44: Tierarztl Prax. 1983;11(4):483-6.
[Treatment of a navicular bone fracture in a horse with pulsing electromagnetic
field (MF therapy)]
[Article in German]
Boening KJ.
Publication Types:
Case Reports
PMID: 6658771 [PubMed - indexed for MEDLINE]
45: Brain Res. 1983 Jan 17;259(1):31-9.
Changes in the somatotopic organization of the cat lumbar spinal cord following
peripheral nerve transection and regeneration.
Lisney SJ.
Glass microelectrodes were used to record the activity of neurones in the left
dorsal horn of the L6 segment of the spinal cord of normal cats and cats in
which the left sciatic and saphenous nerves had been cut 1 or 9 months
previously. In the normal animals the receptive fields of L6 dorsal horn neurons
excited by tactile stimulation of the leg were somatotopically organized, with
neurones in the medial and central dorsal horn having receptive fields on the
distal parts of the leg, particularly the toes, and neurones in the lateral
dorsal horn having receptive fields on the proximal parts of the leg, buttock
and lower back. This somatotopy has been shown before. One month after nerve
section no cells responded to tactile stimulation of the distal leg and cells
in
the medial and central parts of the dorsal horn now had receptive fields on the
proximal leg, buttock and back. There did not appear to be any somatotopic
organization of these new receptive fields. Lateral dorsal horn neurones had
normal receptive fields. Nine months after nerve section neurones in the medial
and central parts of the lumbar dorsal horn had receptive fields on the distal
leg but they showed several abnormal features and there was no evidence of a
return of the somatotopic organization seen in normal animals. Lateral dorsal
horn cells still had normal receptive fields.
PMID: 6824934 [PubMed - indexed for MEDLINE]
46: Ann N Y Acad Sci. 1974;238:575-85.
The effects of pulsed electromagnetic energy on peripheral nerve regeneration.
Wilson DH, Jagadeesh P, Newman PP, Harriman DG.
PMID: 4548339 [PubMed - indexed for MEDLINE]
47: Otolaryngol Head Neck Surg. 1996 Mar;114(3):424-34.
Hyperbaric oxygen treatment after rat peroneal nerve transection and
entubulation.
Santos PM, Zamboni WA, Williams SL, Covey JF, Kienstra MA.
Division of Otolaryngology, Southern Illinois University, Springfield, IL 62794,
USA.
Rat peroneal nerves were transected and entubulated with a Silastic channel. The
experimental group was treated with hyperbaric oxygen to evaluate changes in
acute edema, functional recovery, and histology. Hyperbaric oxygen was
administered with 100% O2 at 2.5 atmospheres absolute for 90 minutes twice a day
for 1 week and then four times a day for 1 week. Acute edema changes based on
nerve water weight and transfascicular area measurements were greater in injured
than in uninjured nerves but demonstrated no differences between hyperbaric
oxygen-treated and -untreated groups 2, 8 and 16 days after surgery. Functional
evaluation with gait analysis demonstrated significant changes between injured
and uninjured group 1, 3, 7, and 13 weeks after injury but no differences
between hyperbaric oxygen-treated and -untreated groups. Thirteen weeks after
the initial injury, elicited muscle force measurements demonstrated no
significant improvement from hyperbaric oxygen treatment of injured nerves.
Histologic evaluation of nerve area, myelinated axon number, myelinated axon
area, myelin thickness, and blood vessel number and area revealed no significant
differences between hyperbaric oxygen-treated and -untreated groups. Hyperbaric
oxygen was not associated with improvement of nerve regeneration with any of the
outcome variables in this model.
PMID: 8649877 [PubMed - indexed for MEDLINE]
48: J Neurosci Res. 1998 Mar 15;51(6):723-34.
Axonal regrowth through a collagen guidance channel bridging spinal cord to the
avulsed C6 roots: functional recovery in primates with brachial plexus injury.
Liu S, Bodjarian N, Langlois O, Bonnard AS, Boisset N, Peulve P, Said G, Tadie
M.
Department of Neurosurgery, Hospital of Bicetre, Le Kremlin-Bicetre, France.
Intraspinal implantation of a collagen guidance channel (CGC) to promote axon
regeneration was investigated in marmosets with brachial plexus injury. After
avulsion of the right C5, C6 and C7 spinal roots, a CGC containing (group B) or
not (group A) a nerve segment, or a nerve graft (group C), was ventro-laterally
implanted into the cord to bridge the ventral horn and the avulsed C6 roots. No
spinal cord dysfunction was observed following surgery. Two months later, the
postoperative flaccid paralysis of the lesioned arm improved. In five months,
a
normal electromyogram of the affected biceps muscle was recorded in all repaired
animals. Motor evoked potentials were obtained with a mean amplitude of 13.37
+/- 13.66 microV in group A, 13.21 +/- 5.16 microV in group B and 37.14 +/-
35.16 microV in group C. The force of biceps muscle contraction was 27.33 +/-
20.03 g (group A), 24.33 +/- 17.03 g (group B) and 37.38 +/- 21.70 g (group C).
Retrograde tracing by horseradish peroxidase showed labelled motoneurons
ipsilaterally located in the C5 and C6 ventral horn, nearby the implantation
site. The mean labelled neurons was 32.33 +/- 21.13, 219.33 +/- 176.29 and 64.33
+/- 23.54 in group A, B and C respectively. Histological analysis presented
numerous myelinated and unmyelinated regenerating axons in the implant of these
animals. Statistical analysis did not show significant difference among the
three repaired groups. Our results indicate that spinal neurons can regenerate
through a CGC to avulsed nerve roots and induce motor recovery in primates.
PMID: 9545086 [PubMed - indexed for MEDLINE]
49: Plast Reconstr Surg. 1998 Nov;102(6):2072-81; discussion 2082-4.
Long-term observation of the effect of peripheral nerve injury in neonatal and
young rats.
Watanabe O, Mackinnon SE, Tarasidis G, Hunter DA, Ball DJ.
Department of Surgery, Washington University School of Medicine, St. Louis, MO,
USA.
The purpose of this study was to observe functional recovery and motoneuron
death after nerve transection-and-repair in neonatal versus young animals. One
hundred nine Lewis rats underwent posterior tibial nerve transection-and-repair
at 6 or 22 days of age. Fifty-two and fifty-seven nerves at the 6- and 22-day
times were used for endpoint analysis at 1, 3, 10, and 14 months. These
assessments included serial functional walking track analysis,
electrophysiologic studies, muscle mass evaluation, motoneuron counts with
retrograde horseradish peroxidase tracing, and histologic and morphometric nerve
analysis. Walking track analysis and nerve conduction velocity indicated
significantly poorer functional regeneration in the 6-day-old group than in the
22-day-old group. Muscle mass in the 6-day-old group did not recover as well as
in the 22-day-old group. Motoneuron numbers stained with horseradish peroxidase
were less in the 6-day-old group than in the 22-day-old group. In contrast,
morphometric analysis did not reach significance. This study suggests that the
same nerve injury sustained in a neonatal rat is less likely to demonstrate
functional recovery than one sustained in a young rat.
PMID: 9811005 [PubMed - indexed for MEDLINE]
50: J Reconstr Microsurg. 1997 Jan;13(1):31-7.
Nerve regeneration after terminolateral neurorrhaphy: experimental study in
rats.
Zhao JZ, Chen ZW, Chen TY.
Zhong Shan Hospital, Shanghai Medical University, People's Republic of China.
Four methods of nerve terminolateral neurorrhaphy (TLN) were studied in rat
experimental model. In Group A, the distal end of a severed peroneal nerve was
sutured end-to-side with an intact tibial nerve trunk, without removal of the
tibial epineurium at the suture site. In Group B, the distal end of a severed
peroneal nerve was sutured end-to-side with the intact tibial nerve trunk, with
removal of the tibial epineurium at the suture site. In Group C, a nerve segment
was bridged between the distal part of the severed peroneal nerve and the intact
tibial nerve with two end-to-side sutures. In Group D, the proximal end of a
severed tibial nerve was sutured end-to-side with the peroneal nerve trunk.
Through electrophysiologic, histologic, and ultrastructural examinations, the
following conclusions were drawn: 1. Nerve regeneration is possible after TLN.
2. The regenerating fibers after TLN have the ability to penetrate the
endoneurium, perineurium, and epineurium. 3. After different methods of TLN, the
regenerating fibers grow in both a flowing-out and a filling-in fashion.
PMID: 9120840 [PubMed - indexed for MEDLINE]
51: J Peripher Nerv Syst. 2003 Mar;8(1):17-22.
Repair of ventral root avulsion using autologous nerve grafts in cats.
Holtzer CA, Marani E, van Dijk GJ, Thomeer RT.
Neuroregulation Group, Department of Neurosurgery, Leiden University Medical
Center, Leiden, The Netherlands.
This study focuses on the capacity of motor axons to elongate from the spinal
cord through an autologous nerve graft into a spinal nerve. Applying a ventral
surgical approach, C7 ventral roots were avulsed from the cord in 12 cats.
Autologous saphenous nerve grafts were implanted into the cord at the ventral
root outlet site and coaptated to the spinal nerve. Outgrowth of axons was
studied at survival times 7, 14, 30, 60 and 120 days, respectively. The results
showed horseradish peroxidase positive motoneurons in the C7 ventral horn after
retrograde labeling, as well as neurofilament and acetylcholinesterase positive
axons in the entire trajectory from spinal cord to spinal nerve. Neurotization
of the C7 spinal nerve started between 14 and 30 days after graft implantation.
In addition electrophysiology provided evidence that outgrowing axons had
re-established functional contact with the spinodeltoid muscle at 120 days after
implantation.
PMID: 12678550 [PubMed - indexed for MEDLINE]
52: J Anat. 1997 Jan;190 ( Pt 1):51-6.
Nerve fibre regeneration across the peripheral-central transitional zone.
Carlstedt T.
Department of Orthopaedics, Karolinska Hospital, Stockholm, Sweden.
Neurons cannot negotiate an elongation across the peripheral (PNS)-central
nervous system (CNS) transitional zone and grow into or out of the spinal cord
in the mature mammal. The astrocytic rich CNS part of the spinal nerve root is
most effective in preventing regeneration even of nerve fibres from transplanted
embryonic ganglion cells. Regeneration of severed nerve fibres into the spinal
cord occurs when the transition zone is absent as in the immature animal. Before
the establishment of a transition zone there is also new growth of neuronal
processes from dorsal horn neurons distally to the injured dorsal root. Thus the
experimental strategy to reestablish spinal cord to peripheral nerve
connectivity has been to delete the transitional region and implant severed
ventral or dorsal roots into the spinal cord. Dorsal root implantation resulted
in reestablished afferent connectivity by new neuronal processes from secondary
sensory neurons in the dorsal horn of the spinal cord extending into the PNS.
The ability for plasticity in these cells allowed for a concurrent retention of
their original rostral projection. Ventral root implantation into the spinal
cord corrected deficit motor function. In a long series of experiments performed
in different species, the functional restitution was demonstrated to depend on
an initial regrowth of motor neuron axons through spinal cord tissue (CNS).
These findings have led to the design of a new surgical strategy in cases of
traumatic spinal nerve root injuries.
Publication Types:
Review
Review, Tutorial
PMID: 9034881 [PubMed - indexed for MEDLINE]
53: J Reconstr Microsurg. 2001 Nov;17(8):631-6.
Direct neurotization of muscles by presynaptic motoneurons.
Brunelli GA.
Department of Orthopaedics, University of Brescia, Italy.
The spinal cord cannot heal after severance because the central nervous system
is "non-permissive" to the advancement of axons that regrow from presynaptic
motoneurons. With the aim of overcoming paraplegia, the author has carried out
extensive experimental research since 1980, first in rats and subsequently in
monkeys, severing the cord and connecting its cephalad stump with the muscular
nerve branches by means of peripheral-nerve grafts, and using various surgical
protocols. Functional connections were established, ascertained by physical,
electrophysiologic, and histologic examinations. In this reported study, it is
demonstrated that presynaptic motoneurons are also able to reconstruct the
cytoskeleton of peripheral neurons, as well as motor end-plates. The possibility
of elongation of the axons of presynaptic motoneurons into the peripheral nerve
up to the muscle had not previously even been hypotheized. This possibility,
which has now been validated, can open the door to new surgical techniques for
spinal-cord lesions. In addition, the author presents preliminary results from
a
single human case, utilizing the surgical procedures of the preceding animal
experiments.
PMID: 11740660 [PubMed - indexed for MEDLINE]
54: Spine. 1994 Mar 15;19(6):705-9.
The effect of electromagnetic pulsing on posterior lumbar spinal fusions in
dogs.
Kahanovitz N, Arnoczky SP, Nemzek J, Shores A.
Anderson Clinic, Arlington, Virginia.
This study evaluated the effect of pulsed electromagnetic fields (PEMF) on the
healing of lumbar spinal fusions. Bilateral posterior facet fusions were
performed at L1-2 and L4-5 in 24 adult mongrel dogs. After surgery, eight
animals were stimulated with a pulse burst type signal (PEMF) for 30 minutes a
day, and eight animals were stimulated with the same PEMF for 60 minutes a day.
The remaining eight animals received no active PEMF stimulation and served as
controls. Four animals from each group were euthanatized at 6 and 12 weeks, and
the facet fusions were evaluated using high resolution radiographs and routine
histology. No statistical difference in the radiographic or histologic
appearance of the fusion mass could be detected between the stimulated and
control groups at either 6 or 12 weeks. The results of this study suggest that
PEMF stimulation had no effect on the healing of the primary posterior spinal
fusions in this controlled experimental canine model.
PMID: 8009336 [PubMed - indexed for MEDLINE]
55: Fysiatr Revmatol Vestn. 1980 Jun;58(3):137-42.
[The effect of an electromagnetic field on the neuromuscular apparatus]
[Article in Czech]
Rehacek J, Benova H, Straub J.
PMID: 7190118 [PubMed - indexed for MEDLINE]
56: Brain Res. 1997 Oct 10;771(1):31-6.
Reinnervation of denervated muscle by transplantation of fetal spinal cord to
transected sciatic nerve in the rat.
Katsuki M, Atsuta Y, Hirayama T.
Department of Orthopaedic Surgery, Asahikawa Medical College, Nishikagura,
Japan.
When motor neurons in the spinal cord are destroyed, regeneration of motor axons
and muscle reinnervation cannot be expected. We attempted reinnervation of the
denervated muscle, i.e. motor unit reconstruction, using transplantation of the
fetal spinal cord to the peripheral nerve. The sciatic nerve of an adult rat was
resected for 20 mm, and a cavity was prepared using an autologous femoral vein
at the distal stump of the nerve. The fetal spinal cord was then transplanted
into the venous cavity. After 3-6 months, no voluntary muscle contraction was
observed due to the absence of communication with the central nervous system.
However, reinnervation of the muscles via the sciatic nerve by the transplanted
spinal neurons was demonstrated electrophysiologically and histochemically. This
suggested that a motor unit can be reconstructed by fetal spinal cord
transplantation even if the original motor neurons in the spinal cord are not
available.
PMID: 9383005 [PubMed - indexed for MEDLINE]
57: Eur J Oral Sci. 1995 Oct;103(5):299-305.
The effects of low level laser treatment on recovery of nerve conduction and
motor function after compression injury in the rat sciatic nerve.
Khullar SM, Brodin P, Messelt EB, Haanaes HR.
Dept. of Oral Surgery and Oral Medicine, University of Oslo, Norway.
An animal study is presented examining the effect of low level laser (LLL)
treatment on nerve regeneration following axonotmesis. Twenty animals received
a
standardised injury to the right sciatic nerve using a time, load and length
sequence (10 min, 150 N, 5 mm) known to cause extensive axonal degeneration of
the rat sciatic nerve. The LLL treatment was administered using a hand-held
laser probe in light contact with the skin on the dorsal aspect of the hind leg
overlying the site of the axonotmesis injury to the sciatic nerve. A group of
10
animals were treated with 6J of LLL (GaAlAs 830 nm) daily for a period of 28 d.
Ten more animals were treated daily with a sham exposure setting and served as
controls. Nerve function was assessed by a recognised method of walking tract
print analysis; the "Sciatic Functional Index" (SFI), and nerve regeneration was
assessed by recording the evoked compound action potentials (cAP) in the common
peroneal nerve. At 21 d post-injury, the laser-treated group had a significantly
lower median SFI than the sham laser-treated group, indicating that the real
laser treatment had improved functional recovery in the nerve. However, no
differences were found between the evoked cAP parameters that were measured in
the laser-treated and sham laser-treated groups. Histological examination
reiterated the lack of difference between the two groups. Consequently, the
effects of LLL on recovery must have occurred more peripherally to the point
measured.
PMID: 8521121 [PubMed - indexed for MEDLINE]
58: J Bone Joint Surg Am. 1981 Apr;63(4):511-23.
Treatment of ununited tibial diaphyseal fractures with pulsing electromagnetic
fields.
Bassett CA, Mitchell SN, Gaston SR.
One hundred and twenty-five patients with one hundred and twenty-seven ununited
fractures of the tibial diaphysis were treated exclusively with pulsing
electromagnetic fields. The over-all success rate in healing of the fracture
with this surgically non-invasive out-patient method was 87 per cent. The
success rate was not materially affected by the age or sex of the patient, the
length of prior disability, the number of previous failed operations, or the
presence of infection or metal fixation.
PMID: 7217117 [PubMed - indexed for MEDLINE]
59: Izv Akad Nauk SSSR Biol. 1981 Sep-Oct;(5):774-80.
[Acute experimental emotional stress in rabbits in a modulated electromagnetic
field]
[Article in Russian]
Gorbunova AV, Petrova NV, Portugalov VV, Sudakov SK.
PMID: 7197697 [PubMed - indexed for MEDLINE]
60: Clin Orthop. 1981 Jan-Feb;(154):136-48.
Congenital "pseudarthroses" of the tibia: treatment with pulsing electromagnetic
fields.
Bassett CA, Caulo N, Kort J.
During the past seven years, 34 patients with infantile nonunions associated
with congenital "pseudarthroses" completed treatment with pulsing
electromagnetic fields (PEMFs). An analysis of results reveals that 17/34 (50%)
have achieved complete healing with biomechanically sound union and radiographic
demonstration of remedullarization. Union with function, i.e., healing with
continued need for protection, was achieved in 7/34 (21%). Failure was the
outcome in 10/34 patients (29%). Most of these occurred in males with a history
of early fracture (less than 1 year) and with spindled, hypermobile lesions
(Type III). During the early period of the study, PEMFs were the sole means of
treatment. After a "coil effect" had been demonstrated, surgical realignment,
immobilization and grafting were combined with PEMF treatment. Fundamentals of
orthopedic management developed by the larger experience with adult nonunions
were found to apply equally to infantile nonunions treated with PEMFs. These
include effective immobilization of the fracture site and controlled "stress
working" during recovery to facilitate gradual remodeling. PEMFs have been
demonstrated to be a potentially useful adjunct in the orthopedic surgeon's
armamentarium for treating infantile nonunions (congenital "pseudarthroses").
PMID: 6781806 [PubMed - indexed for MEDLINE]
61: Equine Vet J. 1989 May;21(3):201-5.
A preliminary investigation of the effect of selected electromagnetic field
devices on healing of cannon bone osteotomies in horses.
Sanders-Shamis M, Bramlage LR, Weisbrode SE, Gabel AA.
Department of Clinical Sciences, Ohio State University, College of Veterinary
Medicine, Columbus 43210.
The effect of electrical stimulation by means of selected electromagnetic field
devices on healing of cannon bone osteotomies in horses was examined. The
defects were created as 3 cm x 1 mm longitudinal osteotomies through the dorsal
cortices of the mid-metacarpi/metatarsi of adult horses. This type of defect
would asses bone healing in a situation similar to an acute, stable fracture of
the cortex. Three electromagnetic devices of different design were tested in
three different groups of horses. Healing was evaluated radiographically and
histologically. Results showed that osteotomies treated with the electromagnetic
devices healed similarly to untreated controls. Our conclusion is that the
electromagnetic devices studied did not have a local effect on the repair
process of an acute, stable, osseous defect.
PMID: 2731509 [PubMed - indexed for MEDLINE]
62: Zh Ushn Nos Gorl Bolezn. 1980 May-Jun;(3):51-3.
[Use of a low-frequency pulsing electromagnetic field in treating inflammatory
diseases of the ENT organs]
[Article in Russian]
Ozinkovskii VV.
Publication Types:
Case Reports
PMID: 7385978 [PubMed - indexed for MEDLINE]
63: J Physiol. 2001 May 1;532(Pt 3):835-49.
Size of myelinated nerve fibres is not increased by expansion of the peripheral
field in cats.
Gordon T, Rafuse VF.
Department of Pharmacology, Division of Neuroscience, University of Alberta,
Edmonton, Alberta, Canada T6G 2H7. tessa.gordon@ualberta.ca
This study tests the hypothesis that target size regulates the size of
myelinated sensory and motor fibres in peripheral nerves. Cat medial
gastrocnemius (MG) muscles were partially denervated and the size of the
remaining nerve fibres that sprouted was examined 6.4 +/- 0.9 months later to
determine whether nerve fibre size increased with target size.
Electrophysiological and morphometric analyses were used to quantify myelinated
nerve fibre size. Charge measurements from dorsal and ventral roots were used
to
electrophysiologically quantify the relative number of cut nerve fibres and the
average size of the remaining intact sensory and motor nerve fibres. Medial
gastrocnemius muscle and motor unit forces provided indirect measurements of the
increase in target size. Conduction velocities and amplitude of unitary action
potentials of motor nerve fibres innervating single motor units were also
measured after partial denervation. Electrophysiological measurements of nerve
fibre size and morphometric measurements of outer fibre perimeters and fibre
areas concurred and demonstrated that myelinated nerve fibres supplying
partially denervated MG muscles did not increase in size in parallel with the
increase in the target size. Thus, unlike non-myelinated nerve fibres, the size
of myelinated nerve fibres does not increase as target size increases.
Retrograde control of size in non-myelinated but not in myelinated nerve fibres
demonstrates differences in plasticity of neurons in the somatic and autonomic
nervous systems.
PMID: 11313450 [PubMed - indexed for MEDLINE]
64: Ann Otol Rhinol Laryngol. 1997 Jun;106(6):506-12.
End-to-side neurorrhaphy resulting in limited sensory axonal regeneration in a
rat model.
Tarasidis G, Watanabe O, Mackinnon SE, Strasberg SR, Haughey BH, Hunter DA.
Department of Otolaryngology-Head and Neck Surgery, Washington University School
of Medicine, St Louis, Missouri 63110, USA.
This study evaluated reinnervation of an end-to-side neurorrhaphy and the
resultant functional recovery in a rat model. The cut distal posterior tibial
nerve was repaired to the side of an intact peroneal nerve. In one group, the
epineurium of the peroneal nerve was left intact; in another group, the
epineurium was stripped; in the third experimental group, a perineurial slit was
created. Evaluations included walking track analysis, nerve conduction studies,
muscle mass measurements, retrograde nerve tracing, and histologic evaluation.
Walking tracks indicated poor functional recovery. No significant difference in
nerve conduction between the experimental and control groups was seen.
Gastrocnemius muscle mass measurements revealed no functional recovery in the
end-to-side groups. Retrograde nerve tracing revealed minimal staining of motor
neurons. However, sensory neuronal staining of the dorsal root ganglia occurred
in all groups. Histology revealed minimal myelinated axonal regeneration. These
results suggest that predominantly sensory neural regeneration occurs in an
end-to-side neurorrhaphy at an end point of 16 weeks.
PMID: 9199612 [PubMed - indexed for MEDLINE]
65: Plast Reconstr Surg. 1998 Aug;102(2):430-6; discussion 437-8.
Motor versus sensory neuron regeneration through collagen tubules.
Madorsky SJ, Swett JE, Crumley RL.
Department of Otolaryngology-Head and Neck Surgery, University of California
Irvine, Orange 92868, USA.
Differences in regeneration of sensory and motor nerves were studied in rats to
determine the effects of entubulation with collagen conduits. The rat sciatic
nerve was repaired either with a 10-mm saline-filled gap or with a no-gap
end-to-end repair cuffed within collagen tubules. These repairs were compared
with the standard epineurial repairs. The populations of regenerated motor and
sensory neurons in the peroneal nerves of all repairs were compared against the
populations of normal peroneal neurons using horseradish peroxidase retrograde
labeling. The epineurial repair resulted in regeneration of 65 percent (409 +/-
150) of motor neurons and 79 percent (2127 +/- 516) of sensory neurons (n = 6).
The no-gap end-to-end repair in a collagen tubule resulted in regeneration of
53
percent (338 +/- 203) of motor and 70 percent (1893 +/- 794) of sensory neurons
(n = 7). In the 10-mm gap repair, only 6.2 percent (39 +/- 18) of motor neurons
but 63 percent (1710 +/- 557) of sensory neurons regenerated (n = 5). These
results show that collagen entubulation supports nerve regeneration in
end-to-end nerve repairs comparably to standard epineurial suture repairs. With
the 10-mm gap repairs in collagen tubules, sensory neurons regenerated
consistently better than motor neurons in the same environment. Therefore,
intrinsic differences exist between motor and sensory neuron regeneration in the
same nerve.
PMID: 9703080 [PubMed - indexed for MEDLINE]
66: J Neurophysiol. 1995 Feb;73(2):651-61.
Rescue of motoneuron and muscle afferent function in cats by regeneration into
skin. I. Properties of afferents.
Johnson RD, Taylor JS, Mendell LM, Munson JB.
Department of Neuroscience, University of Florida, Gainesville 32610-0244, USA.
1. In this study we investigate the peripheral receptive field properties and
spinal cord connections of low-threshold muscle afferent fibers
cross-regenerated into the skin to determine whether a cutaneous target can
rescue physiological functions lost after chronic axotomy. 2. In adult cats the
medial gastrocnemius (MG) muscle nerve was coated with the distal cut end of
either the caudal or lateral cutaneous sural nerves and allowed to regenerate
into the hairy skin (postoperative period 6-30 mo). During terminal acute
experiments we made recordings of single MG afferent fibers in dorsal root
filaments and peripheral nerve. Conduction velocity and receptive field
characteristics were determined for each fiber. In addition, the MG nerve was
stimulated to elicit cord dorsum potentials and monosynaptic excitatory
postsynaptic potentials (EPSPs) in heteronymous motoneurons. As controls,
studies were carried out after MG nerve axotomy (postoperative period 2.5-12
mo). 3. After innervation of the skin, MG muscle afferent fibers exhibited
firing characteristics and proximal segment conduction velocities like those of
normal MG afferents. Responses to skin and hair stimulation consisted primarily
of slowly adapting, stretch-sensitive, and steady discharge patterns, all common
in normal muscle afferents but not in cutaneous afferents. These properties were
observed despite the innervation of touch domes and single hairs, suggesting
that the peripheral physiology of muscle afferents is a function of the axonal
membrane and is not respecified by a cutaneous target and/or receptors. 4. Cord
dorsum potentials were characteristic of those elicited by intact muscle
afferents rather than skin afferents and showed recovery of configurations lost
after chronic axotomy. 5. The monosynaptic EPSPs elicited in lateral
gastrocnemius-soleus motoneurons also recovered from the reduction in amplitude
observed after chronic axotomy. The configurations of these EPSPs were
characteristic of muscle afferents rather than skin afferents. 6. These
experiments demonstrate that the peripheral and central physiological properties
of muscle afferents are rescued from the axotomy state if the afferents are
allowed to reinnervate skin. We found no evidence that respecification had
occurred to bring the function of muscle afferents into accord with the new
cutaneous target.
PMID: 7760124 [PubMed - indexed for MEDLINE]
67: JAMA. 1982 Feb 5;247(5):623-8.
Pulsing electromagnetic field treatment in ununited fractures and failed
arthrodeses.
Bassett CA, Mitchell SN, Gaston SR.
Pulsing electromagnetic fields (PEMFs) induce weak electric currents in bone by
external coils on casts or skin. This surgically noninvasive, outpatient method,
approved by the Food and Drug Administration in November 1979, produced
confirmed end results in 1,007 ununited fractures and 71 failed arthrodeses,
worldwide. Overall success at Columbia-Presbyterian Medical Center was 81%;
internationally, 79%; and in other patients in the United States, 76%. Treatment
with PEMFs was effective in 75% of 332 patients (a subset) with an average
4.7-year disability duration, an average of 3.4 previous operative failures to
produce union, and a 35% rate of infection. Eighty-four percent of carpal
naviculars and 82% of femoral neck-trochanteric nonunions were united. After
attempted arthrodeses could not salvage a failed total-knee prosthesis, PEMFs
promoted healing in 85% of patients. When coils were unsuccessful alone,
combining them with surgical repair was effective.
PMID: 7054564 [PubMed - indexed for MEDLINE]
68: J Neurosci Res. 1999 Jan 15;55(2):230-7.
Electromagnetic fields influence NGF activity and levels following sciatic nerve
transection.
Longo FM, Yang T, Hamilton S, Hyde JF, Walker J, Jennes L, Stach R, Sisken BF.
Department of Neurology, UCSF/VAMC, San Francisco, California, USA.
LFM@itsa.UCSF.edu
Pulsed electromagnetic fields (PEMF) have been shown to increase the rate of
nerve regeneration. Transient post-transection loss of target-derived nerve
growth factor (NGF) is one mechanism proposed to signal induction of early nerve
regenerative events. We tested the hypothesis that PEMF alter levels of NGF
activity and protein in injured nerve and/or dorsal root ganglia (DRG) during
the first stages of regeneration (6-72 hr). Rats with a transection injury to
the midthigh portion of the sciatic nerve on one side were exposed to PEMF or
sham control PEMF for 4 hr/day for different time periods. NGF-like activity was
determined in DRG, in 5-mm nerve segments proximal and distal to the transection
site and in a corresponding 5-mm segment of the contralateral nonoperated nerve.
NGF-like activity of coded tissue samples was measured in a blinded fashion
using the chick DRG sensory neuron bioassay. Overall, PEMF caused a significant
decrease in NGF-like activity in nerve tissue (P < 0.02, repeated measures
analysis of variance, ANOVA) with decreases evident in proximal, distal, and
contralateral nonoperated nerve. Unexpectedly, transection was also found to
cause a significant (P=0.001) 2-fold increase in DRG NGF-like activity between
6
and 24 hr postinjury in contralateral but not ipsilateral DRG. PEMF also reduced
NGF-like activity in DRG, although this decrease did not reach statistical
significance. Assessment of the same nerve and DRG samples using ELISA and
NGF-specific antibodies confirmed an overall significant (P < 0.001) decrease
in
NGF levels in PEMF-treated nerve tissue, while no decrease was detected in DRG
or in nerve samples harvested from PEMF-treated uninjured rats. These findings
demonstrate that PEMF can affect growth factor activity and levels, and raise
the possibility that PEMF might promote nerve regeneration by amplifying the
early postinjury decline in NGF activity.
PMID: 9972825 [PubMed - indexed for MEDLINE]
69: Exp Brain Res. 1999 Mar;125(1):19-27.
Recovery of synapses in axotomized adult cat spinal motoneurons after
reinnervation into muscle.
Brannstrom T, Kellerth JO.
Department of Anatomy, Umea University, Sweden. thomas.brannstrom.us@vll.se
Peripheral axotomy of adult cat spinal motoneurons induces a marked loss of
synaptic boutons from the cell bodies and dendritic trees. The aim of the
present study was to analyze the recovery of synaptic contacts in axotomized
motoneurons following reinnervation into muscle. Adult cat spinal motoneurons
were first deprived of their muscular contacts for 12 weeks and, then, allowed
to reinnervate their target muscle. Two years later, regenerated motoneurons
were labeled with horseradish peroxidase to allow quantitative ultrastructural
analyses of the synaptic covering of the cell bodies and dendrites. Presynaptic
boutons were classified according to their size and the shape of their synaptic
vesicles. Results show that a recovery of synaptic covering occurs in the
axotomized neurons after muscle reinnervation, but it affects various bouton
types to different degrees. The number of S-type boutons synapsing with the soma
was 70% higher after reinnervation than at 12 weeks after axotomy, while the
number of F-type boutons had increased by only 13%. Compared with the normal
situation, the number of S-type boutons synapsing with the proximal dendrites
increased from 82% at 12 weeks after axotomy to 180% in the reinnervated state.
In conclusion, in adult cat spinal motoneurons, the reestablishment of muscular
contact is followed by a normalization of some of the synaptological changes
induced by a prolonged state of axotomy. In certain respects restitution is
incomplete, but in others it results in overcompensation.
PMID: 10100972 [PubMed - indexed for MEDLINE]
70: J Neurocytol. 2001 Nov;30(11):917-26.
Neurofilamentous hypertrophy of intramedullary axonal arbors in intact spinal
motoneurons undergoing peripheral sprouting.
Havton LA, Kellerth JO.
Department of Neurology and Brain Research Institute, Neurologic Rehabilitation
and Neural Repair Programs, University of California, Los Angeles, CA.
90095-1769, USA. LHavton@mednet.ucla.edu
An incomplete motor nerve injury or a partial loss of motoneurons leads to a
partial denervation of skeletal muscle. As part of a compensatory response, the
remaining intact motoneurons undergo peripheral sprouting and increase their
motor unit size. Our knowledge about the responses in the more proximal parts
of
these sprouting motoneurons is sparse, however. We investigated the effects of
an incomplete transection of the medial gastrocnemius (MG) nerve in the adult
cat on the morphology of the intramedullary axon and axon collateral systems of
the remaining intact MG motoneurons. At twelve weeks following the partial
transection of the MG nerve, intracellular recording and labeling techniques
were used to deposit horseradish peroxidase into single intact MG motoneurons
for detailed morphological studies. The light microscopic appearance and caliber
of the intramedullary stem motor axons of the intact MG motoneurons were
indistinguishable from controls. The number and size of the intramedullary
motoraxon collateral systems were also unchanged. However, frequent and marked
hypertrophy of the distal portions of the motoraxon collaterals was encountered.
Electron microscopic studies of the hypertrophied collaterals demonstrated
abnormal accumulations of disorganized neurofilaments arranged in bundles or
whorls. The morphological changes were indistinguishable from the
neurofilamentous hypertrophy that has previously been reported in Wallerian
degeneration, in experimental and human motor neuron disease and in some
regenerating axonal processes of spinal motoneurons. We conclude that,
neurofilamentous hypertrophy of the intramedullary arbors of motor axons may
also be part of a reactive and non-degenerative response in intact motoneurons
undergoing compensatory peripheral sprouting.
PMID: 12373099 [PubMed - indexed for MEDLINE]
71: Neurosci Lett. 1980 Aug;19(1):33-7.
Non-selective distribution of hypoglossal nerve fibers after section and
resuture: a horseradish peroxidase study in the cat.
Mizuno N, Uemura-Sumi M, Matsuda K, Takeuchi Y, Kume M, Matsushima R.
The retrograde tracing method of horseradish peroxidase (HRP) was applied to
examine the process of regeneration of severed hypoglossal nerve in the cat.
After section and resuture of the hypoglossal nerve, the cats were allowed to
survive for 4-6 months. In these cats, distribution of neurons labeled with HRP
injected into the genioglossus muscle was examined and compared with that in the
normal cat. In the operated cats, labeled genioglossus motoneurons were
scattered within all subdivisions of the hypoglossal nucleus, indicating
non-selective distribution of regenerating hypoglossal nerve fibers to the
lingual muscles.
PMID: 7052512 [PubMed - indexed for MEDLINE]
72: Otolaryngol Head Neck Surg. 1998 Oct;119(4):337-41.
End-to-side neurorraphy: a long-term study of neural regeneration in a rat
model.
Tarasidis G, Watanabe O, Mackinnon SE, Strasberg SR, Haughey BH, Hunter DA.
Department of Otolaryngology-Head and Neck Surgery, Washington University School
of Medicine, St. Louis, Missouri, USA.
This study evaluated long-term reinnervation of an end-to-side neurorraphy and
the resultant functional recovery in a rat model. The divided distal posterior
tibial nerve was repaired to the side of an intact peroneal nerve. Control
groups included a cut-and-repair of the posterior tibial nerve and an end-to-end
repair of the peroneal nerve to the posterior tibial nerve. Evaluations included
walking-track analysis, nerve conduction studies, muscle mass measurements,
retrograde nerve tracing, and histologic evaluation. Walking tracks indicated
poor recovery of posterior tibial nerve function in the experimental group. No
significant difference in nerve conduction velocities was seen between the
experimental and control groups. Gastrocnemius muscle mass measurements revealed
no functional recovery in the experimental group. Similarly, retrograde nerve
tracing revealed minimal motor neuron staining in the experimental group.
However, some sensory staining was seen within the dorsal root ganglia of the
end-to-side group. Histologic study revealed minimal myelinated axonal
regeneration in the experimental group as compared with findings in the other
groups. These results suggest that predominantly sensory regeneration occurs in
an end-to-side neurorraphy at an end point of 6 months.
PMID: 9781986 [PubMed - indexed for MEDLINE]
73: J Peripher Nerv Syst. 1996;1(2):111-8.
Experimental surgery in spinal cord lesions by connecting upper motoneurons
directly to peripheral targets.
Brunelli GA, Brunelli GR.
Department of Orthopedics, University of Brescia Medical School, Italy.
This research was aimed at assessing the possibility to connect central
motoneurons with skeletal muscles through PNS segments bypassing a lesion of the
spinal cord. The investigation was performed in 20 non-human primates (Macaca
fascicularis). The surgical paradigm consisted of anastomosing the lateral
bundle of the spinal cord directly with the sciatic nerve of the right hindlimb,
using the peroneal nerve as a graft. The animals were followed-up clinically for
18 months; at the end of this observation period, they underwent
electrophysiological examinations before being killed. Specimens were taken from
the spinal cord, graft, sciatic nerve and potentially reinnervated muscles, and
processed for routine light microscopy and immunohistochemistry. Postoperative
mortality was fairly high (six monkeys), yet the overall outcome was regarded
as
very good because the animals were neither restrained nor intensively cared for.
Five of the surviving monkeys showed clinical, electrophysiological and
histological evidence of successful reinnervation. This research demonstrated
that upper CNS motoneurons are potentially capable of elongating neuritic
processes into the endoneural tubes of a connecting graft, up to reaching a
peripheral nerve (sciatic), and restoring functional connections with the
relevant skeletal muscles.
PMID: 10975719 [PubMed - indexed for MEDLINE]
74: J Bone Joint Surg Am. 1984 Jun;66(5):693-8.
Electromagnetic stimulation of canine bone grafts.
Miller GJ, Burchardt H, Enneking WF, Tylkowski CM.
We evaluated the use of pulsed electromagnetic-field stimulation to affect the
rate of healing or incorporation of segmental autogenous cortical bone grafts
in
the dog in vivo. This non-invasive method of electrical stimulation has been
implicated in increasing bone osteogenesis or augmentation of the repair process
in the canine fibular osteotomy. We utilized two-month and six-month stimulation
protocols. At six months, all of the animals were evaluated biomechanically
using rapid-loading torsional testing. Histological evaluation using
tetracycline labeling was used to evaluate cumulative new-bone formation and
porosity, while graft-host time to union was evaluated roentgenographically
every two weeks. Recent reports have implied that particular pulse
configurations might be effective in improving graft revascularization and
incorporation. The results of our investigation indicated that there was no
significant effect on the biomechanical strength, histological presentation, or
time to union with either two months or six months of pulsed
electromagnetic-field stimulation using the particular waveform described.
PMID: 6373772 [PubMed - indexed for MEDLINE]
75: Arch Orthop Trauma Surg. 1981;99(2):97-103.
Experimental study of interfascicular grafts in the peroneal nerve of the
rabbit.
Yamano Y.
To elucidate the nerve, especially motor nerve, regeneration after
interfascicular grafting, the method most often used clinically, the nerve
grafting was performed on 40 adult rabbits. By resecting 2.0 cm of the right
peroneal nerve, the sural nerve was made into 4 interfascicular grafts under a
operating microscope. The cross section area of the grafts was about the same
as
that of peroneal nerve. Histological and evoked electromyographic observations
were conducted on the maturation of regenerating nerves of up to 24
post-operative months, when the maturation would have been completed. The
present histological and evoked electromyographic observations revealed that
about 70% of nerve, especially motor nerve, recovery was attained after
interfascicular grafts as compared with normal nerve. In the nerve regeneration
after interfascicular grafts, several factors differing from the case of suture
are involved, and these factors were considered from the experimental findings.
PMID: 7316709 [PubMed - indexed for MEDLINE]
76: Muscle Nerve. 1998 Jun;21(6):750-5.
A magnetic evaluation of peripheral nerve regeneration: II. The signal amplitude
in the distal segment in relation to functional recovery.
Kuypers PD, van Egeraat JM, van Briemen LJ, Godschalk M, Hovius SE.
Department of Plastic and Reconstructive Surgery, Erasmus University Rotterdam,
Faculty of Medicine, The Netherlands.
Motor and sensory function in a healthy nerve is strongly related to the number
of neuronal units connecting to the distal target organs. In the regenerating
nerve the amplitudes of magnetically recorded nerve compound action currents
(NCACs) seem to relate to the number of functional neuronal units with larger
diameters regenerating across the lesion. The goal of this experiment was to
compare the signal amplitudes recorded from the distal segment of a
reconstructed nerve to functional recovery. To this end, the peroneal nerves of
30 rabbits were unilaterally transected and reconstructed. After 6, 8, 12, 20,
and 36 weeks of regeneration time the functional recovery was studied based on
the toe-spread test, and the nerve regeneration based on the magnetically
recorded NCACs. The results demonstrate that the signal amplitudes recorded
magnetically from the reconstructed nerves increase in the first 12 weeks from
0% to 21% of the amplitudes recorded from the control nerves and from 21% to 25%
in the following 23 weeks. The functional recovery increases from absent to good
between the 8th and the 20th week after the reconstruction. A statistically
significant relation was demonstrated between the signal amplitude and the
functional recovery (P < 0.001). It is concluded that the magnetic recording
technique can be used to evaluate the quality of a peripheral nerve
reconstruction and seems to be able to predict, shortly after the
reconstruction, the eventual functional recovery.
PMID: 9585328 [PubMed - indexed for MEDLINE]
77: Am J Vet Res. 1985 Oct;46(10):2097-103.
Healing of surgically created defects in the equine superficial digital flexor
tendon: effects of pulsing electromagnetic field therapy on collagen-type
transformation and tissue morphologic reorganization.
Watkins JP, Auer JA, Morgan SJ, Gay S.
The effect of pulsing electromagnetic field (PEMF) therapy on the healing of
surgically created defects in equine superficial digital flexor tendons was
evaluated. Defects were created in both front superficial digital flexor tendons
of 20 horses. The defect in 1 limb was exposed to a PEMF for 2 hours daily. The
other limb served as a control. Histologic and immunofluorescent evaluations
were done in horse killed at postsurgical weeks 2, 4, 8, 12, and 24. Therapy
with the PEMF significantly (P less than 0.05) delayed the maturation of the
tissue formed within the defect at postsurgical weeks 8 and 12, as determined
by
histologic examination. The collagen-type transformation was also delayed by the
PEMF therapy, but to a degree that was not significant.
PMID: 4062013 [PubMed - indexed for MEDLINE]
78: J Orthop Res. 1988;6(2):239-47.
Pulsing electromagnetic field stimulation of the in vitro growth plate.
Iannacone WM, Pienkowski D, Pollack SR, Brighton CT.
Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia.
Specific pulsing electromagnetic fields (PEMFs) have been used to stimulate
growth and repair of osteogenic tissues; however, the basis for this specificity
is unknown. Previously, we determined the relevant electromagnetic field
parameters of the clinically used PEMF and independently verified the beneficial
effects of PEMFs on the rabbit fibula fracture healing model. The goal of the
present study was to develop an in vitro model that would permit the
effectiveness of various electric and magnetic field components of the PEMF to
be determined. The costochondral junction (CCJ) of the 21-day-old rat was
exposed in vitro to PEMFs with various electric and magnetic field component
amplitudes. Response of this model to PEMFs was determined by nondestructive
macrophotographic measurement of CCJ growth. Preliminary data indicated that
temperature effects were present in this in vitro system. Subsequent experiments
designed to separate the effects of temperature and PEMFs on the growth of CCJs
in tissue culture were performed. Results indicate that accurate and frequent
temperature measurements must be made for in vitro models being used to study
effects of PEMFs. Small temperature differences induced by the coils used to
produce PEMFs in the CCJ experimental system can have significant stimulatory
effects, and the combined effects of temperature and PEMFs are not linearly
additive in this model. Furthermore, our results suggest that thermal and PEMF
stimuli could affect macrophotographically measured growth of the CCJ by
separate mechanisms or could have a synergistic effect. Therefore, PEMF
stimulation experiments should be performed under strictly "athermal"
conditions.
PMID: 3343630 [PubMed - indexed for MEDLINE]
79: Exp Physiol. 1991 Jul;76(4):473-94.
Electrical fields, nerve growth and nerve regeneration.
McCaig CD, Rajnicek AM.
School of Biomedical Sciences, Division of Physiology, Marischal College,
University of Aberdeen.
The presence of voltage gradients within developing and damaged tissues led to
the notion that the resultant electrical fields provide instructional cues to
cells. Field effects on avian and amphibian neurones in vitro include increased
differentiation, turning of neurites towards the cathode, increased rate of
growth towards the cathode, resorption of anodefacing neurites, increased
branching and increased filopodial activity. Electric fields enhance
regeneration of damaged PNS and CNS neurones in animals as diverse as lampreys,
frogs, rats and guinea-pigs, but the mechanisms by which fields produce their
effects are not understood. Further examination of the interaction of fields
with intracellular elements, such as the cytoskeleton and second messenger
systems, may offer some insight.
Publication Types:
Review
Review, Academic
PMID: 1910756 [PubMed - indexed for MEDLINE]
80: J R Coll Surg Edinb. 1982 Mar;27(2):102-7.
Pulsing electromagnetic fields in the treatment of non-union of fractures.
Caullay JM, Mann TS.
Publication Types:
Case Reports
PMID: 7086715 [PubMed - indexed for MEDLINE]
81: Physiol Res. 1999;48(6):483-9.
Permanent alterations of spinal cord reflexes following nerve lesion in newborn
rats.
Vejsada R, Palecek J, Hnik P.
Institute of Physiology, Academy of Sciences of the Czech Republic, Prague.
Sciatic nerve lesion in newborn rats is known to cause degeneration of a large
number of axotomized motoneurones and spinal ganglion cells. Some of the
surviving motoneurones exhibit abnormal firing properties and the projection
pattern of central terminals of sensory neurones is altered. We report here on
long-term changes in spinal cord reflexes in adult rats following neonatal nerve
crush. In acutely spinalized and anaesthetized adult rats 4-6 months old in
which the sciatic nerve had been crushed on one side at birth, the tibial nerve,
common peroneal nerve or sural nerve were stimulated on the reinnervated and
control side and reflex responses were recorded from the L5 ventral spinal
roots. Ventral root responses (VRRs) to tibial and peroneal nerve stimulation
on
the side of the nerve lesion were significantly smaller in amplitude
representing only about 15% of the mean amplitude of VRRs on the control side.
The calculated central delay of the first, presumably monosynaptic component of
the VRR potential was 1.6 ms on the control side while the earliest VRR wave on
the side of the nerve lesion appeared after a mean central latency of 4.0 ms
that seems too long to be of monosynaptic origin. These results suggest that
neonatal sciatic nerve injury markedly alters the physiological properties and
synaptic connectivity in spinal cord neurones and causes a marked depression of
spinal cord responses to peripheral nerve stimulation.
PMID: 10783914 [PubMed - indexed for MEDLINE]
82: J Neurosci Res. 1997 Aug 15;49(4):425-32.
Axonal regrowth through collagen tubes bridging the spinal cord to nerve roots.
Liu S, Peulve P, Jin O, Boisset N, Tiollier J, Said G, Tadie M.
Department of Neurosurgery, Hospital of Bicetre, Le Kremlin Bicetre, France.
The capacity of central nervous system (CNS) axons to elongate from the spinal
cord to the periphery throughout a tubular implant joining the ventral horn of
the spinal cord to an avulsed root was investigated in a model of brachial
plexus injury. The C5-C7 roots were avulsed by controlled traction and the C6
root was bridged to the spinal cord over a 3 mm gap by the use of a collagen
cylinder containing or not containing an autologous nerve segment, or an
autologous nerve graft. Nine months later, the functionality and the quality of
the axonal regrowth was evaluated by electrophysiology, retrograde labelling of
neurons, and histological examination of the gap area. A normal electromyogram
of the biceps was observed in all animals where the C6 root was bridged to the
spinal cord. The mean average amplitude of the motor evoked potentials was
comprised between 17.51 +/- 12.03 microV in animals repaired with a collagen
cylinder, and 27.83 +/- 22.62 microV when a nerve segment was introduced in the
tube. In nonrepaired animals spontaneous potentials reflecting a muscle
denervation were observed at electromyography. Retrograde labelling indicated
that a mean number of 58.88 +/- 37.89 spinal cord neurons have reinnervated the
biceps in animals repaired with a tube versus 78.38 +/- 62.11 when a nerve
segment was introduced in the channel, and 97.25 +/- 56.23 in nerve grafting
experiments. Analyses of the repair site showed the presence of numerous
myelinated regenerating axons. In conclusion, our results indicate that spinal
cord neurons can regenerate through tubular implants over a 3 mm gap, and that
this axonal regrowth appeared as effective as in nerve grafting experiments. The
combination of an implant and a nerve segment did not significantly increase the
regeneration rate.
PMID: 9285519 [PubMed - indexed for MEDLINE]
83: Am J Orthod Dentofacial Orthop. 1987 Feb;91(2):91-104.
Effect of pulsed electromagnetic fields on orthodontic tooth movement.
Stark TM, Sinclair PM.
The purpose of this study was to determine whether the application of a simple
surgically noninvasive, pulsed electromagnetic field could increase both the
rate and amount of orthodontic tooth movement observed in guinea pigs. In
addition, the objective was to evaluate the electromagnetic field's effects on
bony physiology and metabolism and to search for possible systemic side effects.
Laterally directed orthodontic force was applied to the maxillary central
incisors of a sample of 40 young male, Hartley guinea pigs (20 experimental, 20
control) by means of a standardized intraoral coil spring inserted under
constricting pressure into holes drilled in the guinea pigs' two maxillary
central incisors. During the experimental period, the guinea pigs were placed
in
specially constructed, plastic animal holders with their heads positioned in an
area of uniform electromagnetic field. Control animals were placed in similar
plastic holders that did not carry the electrical apparatus. The application of
a pulsed electromagnetic field to the experimental animals significantly
increased both the rate and final amount of orthodontic tooth movement observed
over the 10-day experimental period. The experimental animals also demonstrated
histologic evidence of significantly greater amounts of bone and matrix
deposited in the area of tension between the orthodontically moved maxillary
incisors. This increase in cellular activity was also reflected by the presence
of significantly greater numbers of osteoclasts in the alveolar bone surrounding
the maxillary incisors of the experimental animals. After a 10-day exposure to
pulsed electromagnetic field, minor changes in serologic parameters relating to
protein metabolism and muscle activity were noted. The results of this study
suggest that it is possible to increase the rate of orthodontic tooth movement
and bone deposition through the application of a noninvasive, pulsed
electromagnetic field.
PMID: 3468800 [PubMed - indexed for MEDLINE]
84: Nippon Ika Daigaku Zasshi. 1997 Feb;64(1):69-70.
An electron microscopic study of peripheral nerve regeneration with pulsing
electromagnetic fields.
Ito H, Shirai Y, Narita T.
Department of Orthopaedic Surgery, Nippon Medical School, Tokyo, Japan.
PMID: 9119957 [PubMed - indexed for MEDLINE]
85: J Cell Biochem. 1993 Apr;51(4):404-9.
Prospects on clinical applications of electrical stimulation for nerve
regeneration.
Sisken BF, Walker J, Orgel M.
Center for Biomedical Engineering, University of Kentucky, Lexington 40506.
Regenerative capability is limited in higher vertebrates but present in organ
systems such as skin, liver, bone, and to some extent, the nervous system.
Peripheral nerves in particular have a relatively high potential for
regeneration following injury. However, delay in regrowth or growth, blockage,
or misdirection at the injury site, and growth to inappropriate end organs may
compromise successful regeneration, leading to poor clinical results. Recent
studies indicate that low-intensity electrical stimulation is equivalent to
various growth factors, offering avenues to improve these outcomes. We present
a
review of studies using electric and electromagnetic fields that provide
evidence for the enhancement of regeneration following nerve injury. Electric
and electromagnetic fields (EMFs) have been used to heal fracture non-unions.
This technology emerged as a consequence of basic studies [Yasuda, 1953; Fukada
and Yasuda, 1957] demonstrating the piezoelectric properties of (dry) bone. The
principle for using electrical stimulation for bone healing originated from the
work of Bassett and Becker [1962], who described asymmetric voltage waveforms
from mechanically deformed live bone. These changes were presumed to occur in
bone during normal physical activity as a result of mechanical forces, and it
was postulated that these forces were linked to modifications in bone structure.
Endogenous currents present in normal tissue and those that occur after injury
were proposed to modify bone structure [Bassett, 1989]. These investigators
proposed that tissue integrity and function could be restored by applying
electrical and/or mechanical energy to the area of injury. They successfully
applied electrical currents to nonhealing fractures (using surgically implanted
electrodes or pulsed currents using surface electrodes) to aid endogenous
currents in the healing process.(ABSTRACT TRUNCATED AT 250 WORDS)
Publication Types:
Review
Review, Tutorial
PMID: 8496243 [PubMed - indexed for MEDLINE]
86: Microsurgery. 1996;17(11):589-96.
The value of continuous electrical muscle stimulation using a completely
implantable system in the preservation of muscle function following motor nerve
injury and repair: an experimental study.
Williams HB.
Department of Plastic and Reconstructive Surgery, McGill University, Montreal
Children's Hospital, Quebec, Canada.
Functional recovery following motor nerve injury and repair is directly related
to the degree of muscle atrophy that takes place during the period of nerve
regeneration. The extent of this muscle atrophy is related to a number of
factors including the accuracy of nerve repair; the distance through which the
nerve must regenerate; the age of the patient; and the type of nerve injury and
other associated tendon and soft tissue and bony damage. Atrophy of muscle that
is always associated with nerve injury is a combination of disuse and
degeneration. Our hypothesis proposed the following question: "Would continuous
electrical stimulation of the denervated muscle during the period of nerve
regeneration maintain the integrity of the muscle fibers and hence their
potential functional capacity?" We have completed a series of animal studies
(rabbit and canine models) in our laboratory using a completely implantable
system to provide continuous muscle stimulation following nerve injury and
microsurgical repair. In several different experiments, the nerves under study
were cut and repaired at 4 and 12 cm from the muscles to study the effects of
short- and long-term recovery. In all experiments, a beneficial effect was
demonstrated with improved morphology and functional capacity of the
reinnervated stimulated muscles when compared with nonstimulated controls. In
addition, electrical stimulation using this implantable system could be applied
for extended periods without evidence of discomfort in the experimental animals.
PMID: 9514517 [PubMed - indexed for MEDLINE]
87: Muscle Nerve. 1980 Nov-Dec;3(6):509-18.
Muscle reorganization after partial denervation and reinnervation.
Peyronnard JM, Charron L.
The normal rat tibialis anterior (TA) muscle was found to be innervated by
approximately 154 spinal motor cells of which 95 are alpha motoneurons. Most of
these axons ran in the L4 root and connected with glycolytic type 2B muscle
fibers. The L5 root supplied 8.4% to 14.7% of the motor axons of TA muscle and
innervated type 1 and 2A muscle fibers rich in oxidative enzymes. Two months
after section of the peroneal nerve, there was marked fiber-type grouping and
compact rearrangement of the L4 and L5 motor units. After section of the L4
radicular nerve, the TA muscle remained atrophic with no evidence of fiber-type
grouping until 3 months when the L4 regenerating axons reached the muscle.
Similar results were obtained after ligation of the divided ends of the L4
radicular nerve, which delayed but did not prevent reinnervation. These data
suggest that, after partial denervation, muscle reinnervation by collateral
sprouting is a slowly developing process.
PMID: 7453716 [PubMed - indexed for MEDLINE]
88: Electromyogr Clin Neurophysiol. 1998 Jul-Aug;38(5):301-4.
An experimental study about the incorrect electrophysiological evaluation
following peripheral nerve injury and repair.
Hou Z, Zhu J.
Department of Orthopaedics, Liu Hua Qiao Hospital, Guang Zhou, China.
OBJECTIVE: This experiment was designed to explore the reasons of incorrect
electrophysiological evaluation following peripheral nerve repair. METHODS:
Twenty-four New Zealand white rabbits were used and divided into 2 groups. The
first group of animals underwent severance of gastrocnemius muscle nerve and
only the medial branch of the nerve was anastomosed. The second group of rabbits
underwent severance of the muscle nerve as well as sural nerve, then the
proximal end of the sural nerve was anastomosed to the distal end of the muscle
nerve. Electrophysiological and morphological methods were used to study these
models 3 months after the operations. RESULTS: Electrophysiologic comparison of
muscle action potential for group A and B showed a significant difference in the
values (p < 0.05). Morphologic studies showed that the muscle weights of group
B
were significantly lower than those of group A, but the myelin thickness failed
to show any statistical difference between the two groups. CONCLUSION: Results
suggested that one of the sources causing incorrect electrophysiological
evaluation could be misdirected regeneration, resulting from a sensory fascicle
anastomosing to a motor one or vice versa. The unfunctional regeneration showed
low values of muscle action potentials (p < 0.05) as well as excessive
fibrillation potentials, and marked atrophy of the muscles (p < 0.05).
PMID: 9741008 [PubMed - indexed for MEDLINE]
89: Aviat Space Environ Med. 1975 Nov;46(11):1414-7.
Electromagnetic field effects in nerve tissue.
Sandler SS, Smith GS, Albert EN.
In the present work, an attempt has been made to produce structural alterations
in tissue from the nervous system of bullfrogs by means of a high-intensity
electric field. The electric field used to expose the tissue was compased of a
train of high-intensity, short-duration pulses. Theses pulses provide a high
electric-field intensity in the tissue, yet a low enough absorbed-energy density
to cause negligible thermal heating. Exposed and control tissue prepared for
light microscope investigation was stained with thionin and hematoxylin and
eosin stains. No gross histological alterations of the large motor neurons of
the exposed tissue were found when compared with the control tissue.
PMID: 1212150 [PubMed - indexed for MEDLINE]
90: Handchirurgie. 1979;11(1):31-5.
[Nerve regeneration by means of the effect of an intermittent electromagnetic
field. Experimental study on a rabbit]
[Article in German]
Meissl G.
An experiment on healing of transected nerves of rabbits was carried out. Under
microsurgical techniques continuity of the nerve was reestablished by end-to-end
coaptation without creating a defect, so only the elasticity of the nerve tissue
had to be overcome, and by nerve grafting. In both cases treatment with
intermittent high frequency magnetic field was applied continuously. Histologic
studies revealed that the scar at the suture site matured more quickly than
usually and that distal to the site of transection the normal calibre of
regenerated axons was reached within a shorter time than previously.
PMID: 393577 [PubMed - indexed for MEDLINE]
91: Biull Eksp Biol Med. 1986 Nov;102(11):600-2.
[Structural changes in the central nervous system induced by a constant magnetic
field]
[Article in Russian]
Abdullakhozhdaeva MS, Razykov SR.
The effect of the permanent magnetic field (PMF) on the brain cortex of rats has
been assessed. The study was performed on neurons, astrocytes and synapses of
post- and precentral brain cortical zones. CNS sensitivity to PMF was
determined. When the animals were exposed to PMF once or 15 times the changes
in
microstructures were of compensatory-adaptive character, indicative of the
enhancement in their functional activity. When the animals were exposed to PMF
30 times, dystrophic changes underlying the impairment of CNS functional
activity developed, 10 days after the exposure to PMF was discontinued
regenerative intracellular processes were revealed.
PMID: 3779092 [PubMed - indexed for MEDLINE]
92: Eur J Neurosci. 1998 Aug;10(8):2500-10.
Re-establishment of direct synaptic connections between sensory axons and
motoneurons after lesions of neonatal opossum CNS (Monodelphis domestica) in
culture.
Lepre M, Fernandez J, Nicholls JG.
Department of Pharmacology, Biozentrum, University of Basel, 4056 Basel,
Switzerland. Lepre@ubaclu.unibas.ch
For functional recovery after spinal cord injury, regenerating fibres need to
grow and to reform appropriate connections with their targets. The isolated
central nervous system of neonatal opossums aged 1-9 days has been used to
analyse the precision with which neurons become reconnected during regeneration.
In culture these preparations maintain their electrical activity and show rapid
outgrowth through spinal cord crushes or cuts. By recording electrically and by
staining with horseradish peroxidase, we first demonstrated that direct reflex
connections were already present at birth between sensory fibres in one segment
and motoneurons in the same segment and in adjacent segments. As in previous
experiments, 5 days after the spinal cord had been crushed, labelled sensory
fibres grew across the lesion to reach the next segment (Woodward et al. (1993)
J. Exp. Biol., 176, 77-88; Varga et al. (1995a) Eur. J. Neurosci., 7, 2119-2129,
Varga et al. (1995b) Proc. Natl. Acad. Sci. USA, 92, 10959-10963). Beyond the
lesion the labelled axons abruptly changed direction, traversed the spinal cord
and terminated on labelled motoneurons in the ventral horn. In preparations that
had regenerated dorsal root stimulation once again initiated ventral root
reflexes. Electron micrographs revealed synapses made by labelled sensory axons
on motoneurons. Double staining of growing sensory axons and radial glial fibres
showed close association, suggesting guidance. These results indicate that the
original pathway is re-established during repair and that appropriate
connections are reformed after injury.
PMID: 9767381 [PubMed - indexed for MEDLINE]
93: Exp Brain Res. 2001 Aug;139(3):297-302.
Transformation of synaptic vesicle phenotype in the intramedullary axonal arbors
of cat spinal motoneurons following peripheral nerve injury.
Havton LA, Kellerth JO.
Department of Neurology and Brain Research Institute, University of California,
Los Angeles, Reed Neurological Research Center, 90095-1769, USA.
LHavton@mednet.ucla.edu
Permanent transection of a peripheral motor nerve induces a gradual elimination
of whole axon collateral systems in the axotomized spinal motoneurons. There is
also an initial concurrent decrease in the amount of recurrent inhibition
exerted by these arbors in the spinal cord for up to 6 weeks after the injury,
whereas the same reflex action returns to normal by the 12-week postoperative
state. The aim of the present investigation was to study the fine structure of
the intramedullary axonal arbors of axotomized alpha-motoneurons in the adult
cat spinal cord following a permanent peripheral motor nerve lesion. For this
purpose, single axotomized alpha-motoneurons were labeled intracellularly with
horseradish peroxidase at 12 weeks after permanent transection of their
peripheral motor nerve. The intramedullary portions of their motor axon and axon
collateral arbors were first reconstructed at the light microscopic level and
subsequently studied ultrastructurally. This study shows that the synaptic
contacts made by the intramedullary axon collateral arbors of axotomized
motoneurons have undergone a change in synaptic vesicle ultrastructure from
spherical and clear vesicles to spherical and dense-cored vesicles at 12 weeks
after the transection of their peripheral axons. We suggest that the present
transformation in synaptic vesicle fine structure may also correspond to a
change in the contents of these boutons. This may, in turn, be responsible for
the strengthening and recovery of the recurrent inhibitory reflex action exerted
by the axotomized spinal motoneurons following a prolonged permanent motor nerve
injury.
PMID: 11545468 [PubMed - indexed for MEDLINE]
94: J Neurol Sci. 1985 Jan;67(1):1-14.
Effect of ionising radiation on the axon reaction of mouse anterior horn motor
neurons. A histological and immunocytochemical study using a monoclonal antibody
to neurofilament protein.
Moss TH, Lewkowicz SJ.
The changes taking place in irradiated central nervous tissue prior to the onset
of delayed radionecrosis are poorly understood, but functional abnormalities
occurring during the latent interval after irradiation are likely to be of
importance. In order to investigate functional disturbances in neurones during
this period, unilateral sciatic nerve crush was performed in mice following
sub-lethal X-irradiation of the lumbar spinal cord. Alterations in the axon
reaction of anterior horn cells were studied using a monoclonal antibody to
neurofilament protein. With irradiation immediately prior to crush, the normal,
well-defined increase in perikaryal neurofilament protein was significantly
diminished, although there was no concurrent radiation necrosis and no
alterations were seen in contralateral neurones with intact distal axon
processes. The effect was more marked in neurones irradiated one month prior to
nerve crush, and in the non-irradiated nerve crush region regeneration was
delayed, with diminished neurofilament protein in the regenerating axons. These
observations indicate that ionising radiation can progressively impair the
ability of neurones to synthesise neurofilament protein during distal axon
regeneration. This may result from inadequate repair of radiation induced DNA
strand-breaks, but may also follow more generalised damage to protein
transcription enzymes and RNA metabolism.
PMID: 2580059 [PubMed - indexed for MEDLINE]
95: J Neurotrauma. 1994 Oct;11(5):563-72.
Electric field distribution within normal cat spinal cord.
Khan T, Myklebust J, Swiontek T, Sayers S.
Rehabilitation R&D Center, Hines VA Hospital, Illinois.
Electric currents of small magnitude have been used successfully to induce
regrowth of injured spinal cord fibers. The purpose of this study was to
determine the potentials and current density distributions on the surface, as
well as within the spinal cord, after the application of exogenous electric
fields. A 10 microA DC current was applied epidurally to the spinal cord using
two different electrode configurations. The two electrode configurations studied
were: anode and cathode dorsal (D-D) and anode ventral and cathode dorsal (V-D).
Two types of recording electrodes were used to map the potentials on the surface
and within the spinal cord. The recording system consisted of glass
microelectrodes connected to differential amplifiers. The output was recorded
on
a polygraph. The current density was more localized on the dorsal surface of the
spinal cord for the D-D configuration. In contrast, in the V-D configuration,
the current density was greater near the anode on the ventral surface and near
the cathode on the dorsal surface of the spinal cord. As a result of the anode
being located ventrally, there was a more uniform current density distribution
within the spinal cord.
PMID: 7861448 [PubMed - indexed for MEDLINE]
96: Scand J Plast Reconstr Surg Hand Surg. 1999 Sep;33(3):267-72.
The time-dependent difference of GAP-43 expression between sensory neurons and
motoneurons after peripheral nerve transection.
Matsuura Y, Ochi M, Uchio Y, Suzuki G, Iwata A.
Department of Orthopaedics, Shimane Medical University, Shimane-ken, Japan.
The L5 dorsal root ganglion (DRG) cells and L5 anterior horn (AH) cells of rats
were studied and examined immunocytochemically after transection of the sciatic
nerve to find out whether there would be time-dependent differences in the
increase of growth-associated protein (GAP-43) expression between sensory
neurons and motoneurons. On the seventh day after transection at mid-thigh
level, the levels of GAP-43 in the DRG cells significantly increased, while
those in the AH cells began to increase gradually from the 14th day onward.
Transection at the piriform muscle level induced a significant increase in
immunoreactivity of GAP-43 on the third day in the DRG cells, and on the seventh
day in the AH cells. These results showed that sensory neurons expressed GAP-43
immunoreactivity earlier than motoneurons after peripheral nerve transection
regardless of the site, suggesting that sensory neurons might start to produce
cytoskeletons for axonal elongation earlier than motoneurons after nerve
transection.
PMID: 10505438 [PubMed - indexed for MEDLINE]
97: Laryngoscope. 2000 May;110(5 Pt 1):845-53.
A functional model system of an hypoxic nerve injury and its evaluation.
Santos PM.
Otologic Medical Clinic, Inc., Head and Neck Division, Oklahoma City, Oklahoma
73112, USA.
OBJECTIVES/HYPOTHESIS: Develop an hypoxic peripheral nerve injury model with a
controlled injury type and two types of clinically relevant physiological
measurements of function during and after recovery. The model, controlling for
injury and measurement variables, would have predictable outcomes in function.
The functional model could test potential therapeutic interventions with greater
sensitivity. STUDY DESIGN: Twenty-one rats were used in preliminary studies
evaluating peroneal nerve injury types and functional model evaluation.
Forty-eight rats were used in a controlled and blinded evaluation of the injury
model followed by treatment with hyperbaric oxygen (HBO) as a potential
therapeutic intervention and evaluated with functional models. METHODS:
Preliminary studies compared nerve injuries: epineurectomy, epineurectomy with
crush and transection with autograft for rate of return of function and final
extent of return of function. The gait analysis model was also evaluated and
modified to decrease variability. The final study evaluated peroneal
epineurectomy and nerve crush injury with serial gait analysis during recovery,
final elicited maximum force measurements, and histological analysis. Half of
the animals were treated with HBO during recovery (ANOVA or regression
statistical analysis were used to determine group differences.). RESULTS:
Preliminary studies suggested that the peroneal nerve injury model of an
epineurectomy with crush of specified length and a modification of the gait
analysis model would yield a useful and predictable injury outcome. The final
study resulted in predicted and consistent injury outcomes. In the HBO treatment
group, a 12% improvement in function 5 days after HBO treatment was demonstrated
(P < .03), but no long-term or histological benefit was seen. CONCLUSION: A
reliable hypoxic nerve injury model has been developed and tested utilizing two
functional methods as the primary outcome variables.
PMID: 10807363 [PubMed - indexed for MEDLINE]
98: J Bone Joint Surg Am. 1989 Mar;71(3):411-7.
Prevention of osteoporosis by pulsed electromagnetic fields.
Rubin CT, McLeod KJ, Lanyon LE.
Musculo-Skeletal Research Laboratory, Department of Orthopaedics, State
University of New York, Stony Brook 11794.
Using an animal model, we examined the use of pulsed electromagnetic fields,
induced at a physiological frequency and intensity, to prevent the osteoporosis
that is concomitant with disuse. By protecting the left ulnae of turkeys from
functional loading, we noted a loss of bone of 13.0 per cent compared with the
intact contralateral control ulnae over an eight-week experimental period. Using
a treatment regimen of one hour per day of pulsed electromagnetic fields, we
observed an osteogenic dose-response to induced electrical power, with a maximum
osteogenic effect between 0.01 and 0.04 tesla per second. Pulse power levels of
more or less than these levels were less effective. The maximum osteogenic
response was obtained by a decrease in the level of intracortical remodeling,
inhibition of endosteal resorption, and stimulation of both periosteal and
endosteal new-bone formation. These data suggest that short daily periods of
exposure to appropriate electromagnetic fields can beneficially influence the
behavior of the cell populations that are responsible for bone-remodeling, and
that there is an effective window of induced electrical power in which bone mass
can be controlled in the absence of mechanical loading.
PMID: 2925715 [PubMed - indexed for MEDLINE]
99: J Neurosci Res. 1999 Jun 1;56(5):506-17.
Reinnervation of denervated lumbar ventral roots and their target muscle by
thoracic spinal motoneurons via an implanted nerve autograft in adult rats after
spinal cord injury.
Liu S, Kadi K, Boisset N, Lacroix C, Said G, Tadie M.
Department of Neurosurgery, Hospital of Bicetre, Le Kremlin Bicetre, France.
Intraspinally implanting a nerve autograft (NAG) to promote axonal regeneration
toward periphery was investigated as a surgical treatment for spinal cord injury
in adult rats. Fifteen animals underwent a left hemisection of the spinal cord
at T12 level and an intradural section of all ipsilateral lumbar ventral roots.
In repaired animals (n = 9), the electrophysiologically selected left L3 and L4
lumbar ventral roots supplying the quadriceps muscle were anastomosed to a NAG.
The NAG was taken from the right peroneal nerve and then ventrolaterally
implanted into the cord at a level 7 mm rostral to the hemisection. In the
control group (n = 6), sectioned lumbar ventral roots were left unrepaired. Nine
months later, the animals were assessed with clinical, electrophysiological, and
histological examinations. Muscle action potential and motor evoked potential
were obtained from the denervated/reinnervated quadriceps in all repaired
animals, with a mean amplitude of 918.3+/-328.9 microV and 215.8+/-39.7 microV,
respectively. Horseradish peroxidase retrograde labeling from the
denervated/repaired lumbar ventral roots, performed in five repaired animals,
showed that the mean of labeled neurons, ipsilaterally located in the thoracic
ventral horn near the implantation site, was 145.8+/-111.7. Histological
analysis showed numerous myelinated axons in the NAG and denervated/repaired
lumbar ventral roots of all repaired animals. The study of neuromuscular
junctions furthermore confirmed numerous newly formed endplates appearing in the
denervated/reinnervated quadriceps. These changes were absent in the control
animals. These data indicate that the rostral thoracic spinal motoneurons can
innervate the caudal denervated/repaired lumbar ventral roots and the target
quadriceps via an implanted NAG, thereby inducing some functional recovery in
adult rats after lower thoracic spinal cord injury.
PMID: 10369217 [PubMed - indexed for MEDLINE]
100: J Reconstr Microsurg. 1997 Apr;13(3):177-83.
Functional assessment of tibial-nerve recovery in the cat using gait analysis:
preliminary study.
Lin FM, Pan YC, Dinh TA, Sabbahi M, Shenaq S.
Division of Plastic Surgery, Baylor College of Medicine, Houston, Texas, USA.
The purpose of this study was to investigate gait-pattern changes after complete
tibial nerve lesion in the cat, and to observe whether nerve repair could
reverse some of the changes. In six cats, a 5-cm segment of the tibial nerve was
transected. The nerve gap was then repaired with nerve autograft in three
animals and was unrepaired in three as controls. The walking patterns of the
cats were videotaped, and the hip, knee, ankle, and metatarsophalangeal joint
angles were measured at the beginnings of the F, E1, E2, and E3 phases of the
step cycle. Two weeks after surgery, abnormal gait patterns were observed, and
four gait parameters (E3.Hip, E3.Ankle, E3.M-P, and F.Ankle) were found to be
statistically significantly different from normal. Six months after surgery, the
nerve-graft group had gait-parameter values approaching normal, while the
control group showed no measurable improvement. Correspondingly,
electrophysiologic testing revealed considerable nerve regeneration in the
nerve-graft group but not in the control group. It was concluded that these gait
parameters can be used as valid functional indices to evaluate the degree of
tibial nerve recovery in the cat model.
PMID: 9101447 [PubMed - indexed for MEDLINE]
101: Srp Arh Celok Lek. 1993 Aug-Dec;121(8-12):124-6.
[Use of pulsating high-frequency electromagnetic fields in patients with
diabetic neuropathies and angiopathies]
[Article in Serbian]
Vesovic-Potic V, Conic S.
Belgrade Institute of Rehabilitation.
High-frequency pulsating electromagnetic field therapy was carried out in 22
patients with diabetic polyneuropathy and angiopathy manifested on lower
extremities (18 men, 4 women, aged 48.2 +/- 6.3 years; 10 insulin-dependent
persons, and 12 on oral antidiabetic treatment). The aim of the study was to
verify the effect of this therapy on symptoms, neurophysiological findings and
peripheral circulation. The diagnose of diabetic polyneuropathy was based on the
electromyographic examination of foot and calf muscles, measurement of motor
nerve conduction velocity of peroneal and tibial nerve, and sensory nerve
conduction velocity of sural nerve. Diagnosis of diabetic polyneuropathy was
based on electromyographic examination of the foot and calf muscles, measurement
of the motor nerve conduction velocity of peroneal and tibial nerves, and the
sensory nerve conduction velocity of the sural nerve. Diagnosis of diabetic
angiopathy was established by oscillometric examination, measurement of skin
temperature and claudication distance. The same methods were used for the
evaluation of the therapeutical effect of electromagnetic field. Significant
improvement of symptoms, and of all registered parameters of peripheral
circulation was established after the therapy, but there were no significant
changes of neurophysiological parameters. Therefore, high-frequency pulsating
electromagnetic field is recommended for the treatment of diabetic angiopathy.
In patients with neuropathic changes it can be used as an introduction
procedure, or as an additional procedure to physical agents which are commonly
used in the treatment of peripheral nerve lesion.
PMID: 7725151 [PubMed - indexed for MEDLINE]
102: Neurosurg Clin N Am. 2001 Apr;12(2):353-7.
Acceleration of recovery after injury to the peripheral nervous system using
ultrasound and other therapeutic modalities.
Lazar DA, Curra FP, Mohr B, McNutt LD, Kliot M, Mourad PD.
Department of Neurological Surgery, University of Washington, Seattle 98105,
USA.
Taken together, these studies show the promise of various therapeutic modalities
for the noninvasive treatment of peripheral nerve injury. Further progress on
these promising methods requires determining the biologic mechanisms responsible
for the ability of these modalities to enhance peripheral nerve recovery.
Necessary investigations include validation or refutation of the hypothesis that
these therapies act on various aspects of the natural healing process. Examples
include cellular and molecular processes involved in promoting Wallerian
degeneration and the rate and specificity of axonal regeneration and
remyelination and muscle reinnervation, processes that are distributed between
the regenerating nerve itself, the pathway of the regenerating axon, and the
target of the regenerating nerve. An increased understanding of the biologic
mechanisms underlying the enhancement of peripheral nerve recovery after injury
would lend greater insight into the cellular and molecular mechanisms involved
in successful nerve regeneration and muscle reinnervation. This increased
understanding may also result in clinically beneficial treatments for peripheral
nerve disorders.
PMID: 11525213 [PubMed - indexed for MEDLINE]
103: J Reconstr Microsurg. 1995 May;11(3):189-93.
Experimental study using a direct current electrical field to promote peripheral
nerve regeneration.
Shen N, Zhu J.
Department of Orthopedics, People's Hospital of Hainan Province, Haikou,
People's Republic of China.
A direct current (DC) electrical field was used to stimulate transected and
sutured rat sciatic nerve. Electrophysiologic, morphometric, and functional
assessments were carried out on days 10, 20, 30, and 60 postoperatively. The
results showed that the electrophysiologic index, the diameter and myelin-sheath
thickness of regenerating nerve fibers, the sciatic functional index (SFI), and
the strength of the triceps surae muscle in the experimental group were much
better than those in the control group. This indicated that DC electrical
stimulation could effectively promote peripheral nerve regeneration and produce
positive effects after 3 weeks, and that the stimulator was not rejected by the
host for a relatively long period of time.
PMID: 7650644 [PubMed - indexed for MEDLINE]
104: Neuroscience. 1999;91(1):251-64.
Electrically mediated regeneration and guidance of adult mammalian spinal axons
into polymeric channels.
Borgens RB.
Center for Paralysis Research, Department of Basic Medical Sciences, School of
Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA.
An extracellular electric field has been shown to influence the regeneration of
nerve fibers within the adult mammalian spinal cord. However, in these studies,
few axons were labeled by local application of intracellular markers relative
to
the number of axons transected. This has limited an evaluation of the robustness
of the response, and the direction of growth of regenerating axons that might
be
influenced by the orientation of the applied voltage gradient. In this study,
a
hollow silicone rubber tube (c. 6 mm x 1 mm outside diameter) containing a
cathodal (negative) electrode was inserted longitudinally into the dorsal half
of the adult guinea-pig spinal cord. The electric field ( approximately 100
microV/mm) was imposed within the damaged spinal cord with an implanted d.c.
stimulator for about three weeks. Based on previous studies, this orientation
of
the electric field would be expected to both initiate axonal regeneration and
guide growing axons to, and into, the silicone guidance channel. In experimental
animals (n = 20), a robust regeneration of axons into the tube was observed in
more than half the cases. These axons were traced from surrounding white and
gray matter by anterograde and retrograde labeling using a
tetramethylrhodamine-conjugated dextran as an intracellular marker. Control
animals (n = 16) received tubes with inactive electrodes. It was rare to find
any axons within control guidance channels, since adult mammalian central
nervous system axons do not regenerate. This report provides evidence for not
only the facilitated regeneration of adult mammalian central axons, but also
their guidance, by an imposed electric field.
PMID: 10336075 [PubMed - indexed for MEDLINE]
105: Exp Neurol. 2001 Sep;171(1):170-5.
Repeated injury to the sciatic nerve in immature rats causes motoneuron death
and impairs muscle recovery.
Lowrie MB, Vrbova G.
Division of Biomedical Sciences, Imperial College School of Medicine, London,
SW7 2AZ, United Kingdom.
Injury to the sciatic nerve of newborn rats causes motoneuron death, while the
same insult inflicted 5 days later does not. In this study the effects of
prolonging the period of target deprivation and axonal regeneration were
investigated by inflicting a second nerve crush 6 days after the first, just
before reinnervation of the muscle occurred. Two to 4 months later the number
of
motoneurons supplying soleus, tibialis anterior, and extensor digitorum longus
muscles was established by retrograde labeling with horseradish peroxidase
injected into the muscle. After nerve injury at 5 days there was no significant
loss of motoneurons to any muscle. However, when the injury was repeated, the
number of labeled motoneurons was reduced, suggesting that a significant
proportion had died. Motoneurons to soleus were affected more than those to the
fast muscles, reflecting their lesser maturity. Moreover, motoneurons to soleus
that survived both injuries to their axon failed to grow to their full size. The
relative impairment of recovery of the muscles, indicated by weight and maximal
tetanic tension, mirrored the loss of motoneurons in each case. Previous studies
have suggested that repeated nerve injuries in adult animals can enhance
reinnervation. However, the present results along with those of other recent
studies suggest that immature motoneurons that are repeatedly induced to support
growth of their axons are at greater risk of death and can result in poorer
reinnervation of the muscles. Copyright 2001 Academic Press.
PMID: 11520131 [PubMed - indexed for MEDLINE]
106: IEEE Trans Biomed Eng. 1980 Dec;27(12):722-3.
An estimate of the steady magnetic field strength required to influence nerve
conduction.
Wikswo JP, Barach JP.
PMID: 7461647 [PubMed - indexed for MEDLINE]
107: Rev Chir Orthop Reparatrice Appar Mot. 1981;67(1):11-23.
[Acceleration of repair of non-unions by electromagnetic fields (author's
transl)]
[Article in French]
Sedel L, Christel P, Duriez J, Duriez R, Evrard J, Ficat C, Cauchoix J, Witvoet
J.
This work deals with the results obtained by four French orthopaedic departments
using the electromagnetic field stimulation for non union treatment. This is the
method established by A. Bassett. 37 cases are studied, the results are known
for 35 of them with 6 failures and 29 successes. The failures can be explained
for four of them by a bad application of the device. Concerning the 29
successful cases, the role of the stimulation is discussed. Discarding those who
have been treated a short time after a surgical procedure, those who have been
immobilized more than 6 months and those where the non union could have been a
delayed union, it remains 14 successful cases apparently undisputable. For them
the role of the electromagnetic field stimulation seems real.
Publication Types:
Case Reports
PMID: 6453392 [PubMed - indexed for MEDLINE]
108: Appl Neurophysiol. 1986;49(5):278-84.
Effects of growth, degeneration and regeneration on the sensory motor system.
Mackel R.
Rockefeller University, New York, N.Y.
Evidence was presented for regeneration and growth in the central nervous system
of experimental animals and in the peripheral nervous system of man.
Neurophysiological, neurohistological and neurochemical findings from the
cerebellothalamocortical and the nigrostriatal projection systems as well as the
motoneurons of the anterior horn and facial nucleus were presented and their
possible functional implications discussed. Single unit recordings from
regenerated primary afferents in human peripheral nerves were also shown and
discussed in the light of their clinical relevance. The conclusions were reached
that the findings of positive growth in the CNS following traumatic injury or
in
response to brain implants left little doubt that the CNS possesses the
intrinsic capability of regeneration. The functional and clinical implications
of this inherent capacity awaits further research. Recording the response
behavior of regenerated primary afferents in man, on the other hand, provided
more direct insight into functional deficits and their clinical correlates.
PMID: 3662499 [PubMed - indexed for MEDLINE]
109: Dev Neurosci. 1994;16(1-2):17-24.
Dendritic development in normal lumbar motoneurons and following neonatal nerve
crush in the rat.
O'Hanlon GM, Lowrie MB.
Department of Anatomy and Cell Biology, St. Mary's Hospital Medical School,
Imperial College, London, UK.
Motoneurons from the rat were retrogradely labelled with cholera
toxin-horseradish peroxidase at intervals during normal postnatal development
and following nerve crush at birth. Normal cells displayed a relatively steady
increase in total visible dendritic density which was largely confined to the
dorsomedial direction. After nerve crush at birth, dorsomedially orientated
dendrites failed to achieve normal density, resulting in a significantly smaller
dendritic tree by adulthood. There was also a transient, abnormal extension of
dendrites in the medioventral direction which had regressed to normal levels by
maturity. The predominance of changes in the dorsally directed region of the
dendritic tree suggests that dendritic development of motoneurons is influenced
by synaptic inputs in the dorsal horn.
PMID: 7532567 [PubMed - indexed for MEDLINE]
110: Clin Orthop. 1982 Jun;(166):45-57.
The treatment of congenital pseudarthrosis of the tibia with pulsing
electromagnetic fields. A survey of 52 cases.
Sutcliffe ML, Goldberg AA.
PMID: 7083684 [PubMed - indexed for MEDLINE]
111: Chirurgie. 1997;122(4):252-9.
[Motor reconnection between the damaged cervical cord and the denervated biceps
muscle using an autologous peripheral nerve segment in the adult marmoset]
[Article in French]
Emery E, Horvat JC, Tadie M.
Service de Neurochirurgie du Pr. A. Rey, Hopital Beaujon, clichy.
Our research group is studying, in the primate (marmoset), the conditions of an
anatomical and functional reconstruction of the spinal cord and of its motor
connections, following a focal spinal lesion. In this attempt to repair the
damaged neuronal circuitry, we used long segments of autologous peripheral
nerves joining the injured cervical spinal cord to an aneural region of the
denervated biceps brachialis muscle (7 marmosets) or to the musculocutaneous
nerve (6 marmosets). After retrograde tracing (HRP) and histochemical studies
of
the muscle, we found that a great number of neurons, located mostly in the
ventral part of the grey matter extended axons into the peripheral nerve graft.
Some of these labelled neurons were motoneurons, which could established
functionnal neuromuscular junctions. The muscle regeneration was effective but
slower than already known in rat studies.
PMID: 9501551 [PubMed - indexed for MEDLINE]
112: Exp Neurol. 1996 Jan;137(1):1-14.
Regeneration of respiratory pathways within spinal peripheral nerve grafts.
Decherchi P, Lammari-Barreault N, Gauthier P.
Departement de Physiologie et de Neurophysiologie, URA CNRS 1832, Faculte des
Sciences et des Techniques, Saint-Jerome (Aix-Marseille III), Marseille, France.
Central respiratory neurons exhibit normal activity after axonal regeneration
within blind-ended peripheral nerve grafts (PNGs) inserted near the
corresponding cell bodies in the medullary respiratory centers. Part of these
medullary respiratory neurons project toward the spinal cord and contribute to
descending respiratory pathways that control respiratory motoneurons. The
present work investigates to what extent cervical respiratory pathways could be
directed out of the central nervous system within PNGs inserted distant to the
medullary respiratory nuclei. In adult rats (n = 13), autologous segments of the
peroneal nerve were implanted into the ventrolateral part of the C2 spinal cord
at the level of the descending respiratory pathways. Two to four months after
grafting, electrophysiological recording of teased graft filaments (n = 562)
revealed the presence of regenerated nerve fibers with unitary impulse traffic
(n = 164) in all tested PNGs (n = 6). Respiratory discharges (n = 52)
corresponded to efferent and afferent activity. Efferent respiratory discharges
(n = 32) originated from central respiratory neurons which remained functional
and preserved afferent connections. Retrograde horseradish peroxidase labeling
applied to the distal cut end of PNGs (n = 7) revealed stained (42/1997) neurons
in areas where respiratory cells have been described. Afferent respiratory
discharges (n = 20) were synchronized with lung inflation but their origin
(stretch pulmonary receptors and/or respiratory muscle receptors) was not
determined. On the basis of additional data from light and electron microscopy
of PNGs, comparison was made between anatomical, retrograde labeling, and
electrophysiological data. The main conclusion is that spinal PNGs appear to be
able to promote axonal regeneration of functional respiratory efferent and
afferent pathways.
PMID: 8566201 [PubMed - indexed for MEDLINE]
113: J Neurosci Res. 2000 Dec 15;62(6):821-9.
Motoneurons of the adult marmoset can grow axons and reform motor endplates
through a peripheral nerve bridge joining the locally injured cervical spinal
cord to the denervated biceps brachii muscle.
Emery E, Rhrich-Haddout F, Kassar-Duchossoy L, Lyoussi B, Tadie M, Horvat JC.
Laboratory of Neurobiology, Rene Descartes University, Paris, France.
Reconnection of the injured spinal cord (SC) of the marmoset with the denervated
biceps brachii muscle (BB) was obtained by using a peripheral nerve (PN) bridge.
In 13 adult males, a 45 mm segment of the peroneal nerve was removed: one end
was implanted unilaterally into the cervical SC of the same animal (autograft),
determining a local injury, although the other end was either directly inserted
into the BB (Group A) or, alternatively, sutured to its transected motor nerve,
the musculocutaneous nerve (Group B). From 2-4 months post-surgery, eight out
of
the 10 surviving animals responded by a contraction of the BB to electrical
stimulations of the PN bridge. All ten were then processed for a morphological
study. As documented by retrograde axonal tracing studies using horse radish
peroxidase or Fast Blue (FB), a mean number of 314 (Group A) or 45 (Group B)
spinal neurons, mainly located close to the site of injury and grafting,
re-expressed a capacity to grow and extend axons into the PN bridge. Most of
these regenerated axons were able to grow up to the BB and form or reform
functional motor endplates. Many of the spinal neurons that were retrogradely
labeled with FB simultaneously displayed immunoreactivity for choline
acetyl-transferase and consequently were assumed to be motoneurons.
Reinnervation and regeneration of the BB were documented by methods revealing
axon terminals, endplates and myofibrillary ATPase activity. Our results
indicate that motoneurons of the focally injured SC of a small-sized primate
can, following the example of the adult rat, re-establish a lost motor function
by extending new axons all the way through a PN bridge connected to a denervated
skeletal muscle. Copyright 2000 Wiley-Liss, Inc.
PMID: 11107167 [PubMed - indexed for MEDLINE]
114: J Comp Neurol. 1981 Jun 20;199(2):277-91.
Effect of peripheral nerve injury on receptive fields of cells in the cat spinal
cord.
Devor M, Wall PD.
When the sciatic and saphenous nerves are cut and ligated in adult cats, the
immediate effect is the production of a completely anesthetic foot and a region
in medial lumbar dorsal horn where almost all cells have lost their natural
receptive fields (RFs). Beginning at about 1 week and maturing by 4 weeks, some
40% of cells in the medial dorsal horn gain a novel RF on proximal skin, that
is, upper and lower leg, thigh, lower back, or perineum. This new RF is supplied
by intact proximal nerves and not by sciatic and saphenous nerve fibers that
sprouted in the periphery. During the period of switching of RFs from distal to
proximal skin there was no gross atrophy of dorsal horn grey matter and no
Fink-Heimer stainable degeneration of central arbors and terminals of
peripherally axotomized afferents. In intact animals medial dorsal horn cells
showed no sign of response to mechanical stimulation of proximal skin. RFs of
some of the cells had spontaneous variations in size and sensitivity, but these
were not nearly sufficient to explain the large shifts observed after chronic
nerve section. Tetanic electrical stimulation of skin or peripheral nerves often
caused RFs to shrink, but never to expand. Although natural stimuli of proximal
skin would not excite medial dorsal horn cells in intact or acutely deafferented
animals, it was found that electrical stimulation of proximal nerves did excite
many of these cells, often at short latencies. In the discussion we justify our
working hypothesis that the appearance of novel RFs is due to the strengthening
or unmasking of normally present but ineffective afferent terminals, rather than
to long-distance sprouting of new afferent arbors within the spinal cord.
PMID: 7251942 [PubMed - indexed for MEDLINE]
115: Muscle Nerve. 1993 Jun;16(6):634-41.
A comparison of electric and magnetic compound action signals as quantitative
assays of peripheral nerve regeneration.
Kuypers PD, Gielen FL, Wai RT, Hovius SE, Godschalk M, van Egeraat JM.
Erasmus University Rotterdam, Faculty of Medicine, Department of Plastic
Surgery, The Netherlands.
The evaluation of peripheral nerve regeneration is of great interest in clinical
as well as in experimental situations. However, there are few techniques that
give early and quantitative information on the status of the regeneration
process. If quantitative assays would be available, different surgical
techniques and medications could be evaluated more accurately in relation to
axonal ingrowth and functional recovery. The purpose of this study was to
investigate the merits of nerve compound action signals (NCASs) recorded
electrically and signals recorded with a novel magnetic recording technique. We
compared the two techniques in the rabbit peroneal nerve, 2, 4, 6, and 8 weeks
after a nerve reconstruction. Our conclusions are that the signals recorded with
the magnetic sensor are far more reproducible and less prone to stimulus
artifact than the electrically recorded signals. Furthermore, the magnetic
recording shows that the number of axons that have regenerated increases with
time. Previously, this could only be determined with histological studies. Other
ingrowth parameters that can be quantified are the average ingrowth distance,
and the variation between axons in ingrowth velocity.
PMID: 8502261 [PubMed - indexed for MEDLINE]
116: Clin Orthop. 1984 Jul-Aug;(187):272-6.
Treatment of nonuniting osteotomies with pulsating electromagnetic fields. A
controlled animal experiment.
Enzler MA, Sumner-Smith G, Waelchli-Suter C, Perren SM.
To evaluate treatment of nonunions or pseudarthrosis in humans by pulsating
electromagnetic fields (PEMF), the authors tested the method in four- to
six-year-old beagle dogs with midshaft osteotomies of both ulnae. This type of
osteotomy in dogs leads to nonunion. After surgery one foreleg of each dog was
stimulated for an average of 25 days; the second foreleg served as a control.
Subsequently all ulnae were harvested, radiographs were obtained, and the
stiffness of the callus was mechanically tested. Thus, the reputed efficiency
is
not confirmed by controlled experiments on dogs. The stimulated bones were
neither radiologically nor mechanically superior to the controls.
PMID: 6744729 [PubMed - indexed for MEDLINE]
117: Eur J Neurosci. 1997 Dec;9(12):2774-7.
Effects of neurotransplants and BDNF on the survival and regeneration of injured
adult spinal motoneurons.
Novikova L, Novikov L, Kellerth JO.
Department of Anatomy, Umea University, Sweden.
We compared the effects of peripheral nerve grafts, embryonic spinal cord
transplants and brain-derived neurotrophic factor (BDNF) on the survival and
axon regeneration of adult rat spinal motor neurons undergoing retrograde
degeneration after ventral root avulsion. Following implantation into the
dorsolateral funiculus of the injured spinal cord segment, neither a peripheral
nerve graft nor a combination of peripheral nerve graft with embryonic spinal
cord transplant could prevent the retrograde motor neuron degeneration induced
by ventral root avulsion. However, intrathecal infusion of BDNF promoted
long-term survival of the lesioned motor neurons and induced abundant motor axon
regeneration from the avulsion zone along the spinal cord surface towards the
BDNF source. A combination of ventral root reconstitution and BDNF treatment
might therefore be a promising means for the support of both motor neuron
survival and guided motor axon regeneration after ventral root lesions.
PMID: 9517482 [PubMed - indexed for MEDLINE]
118: Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi. 2000 Mar;14(2):87-9.
[A functional evaluation on peripheral nerve regeneration enhanced by targeted
muscular injection of ciliary neurotrophic factor]
[Article in Chinese]
Han J, Zhang J, Zhang Y.
Department of Hand Surgery, Third Hospital of Hebei Medical University,
Shijiazhuang Hebei, P. R. China 050051.
OBJECTIVE: To investigate the effects of targeted muscular injection of ciliary
neurotrophic factor (CNTF) on the regeneration of injured peripheral nerves.
METHODS: The left sciatic nerves of 80 Sprague-Dawley rats were excised to form
6 mm defect and the two ends were bridged by silicone tubes, they were randomly
divided into two groups, CNTF group and normal saline (NS) group. The CNTF group
was given recombinant human CNTF, 1 mg/kg every other day for 30 days, and the
NS group was given equal quantity of normal saline as NS group. The sciatic
nerve functional index (SFI), electrophysiological assessment, morphometric
analysis of axons, and choleratoxin horseradish peroxidase (CB-HRP)
retrograde-labelling were measured postoperatively. RESULTS: The SFI,
electrophysiological parameters (nerve conduction velocity, latency and
amplitude of compound muscle action potentials), myelinated axons counts, mean
axons diameters and myelin sheath thickness, number of CB-HRP labelled ventral
horn motor neurons of spinal cord were significantly higher in CNTF group than
that of NS group. CONCLUSION: Targeted muscular injection of CNTF can promote
the regeneration of peripheral nerve and improve the nerve functional recovery.
PMID: 11778199 [PubMed - indexed for MEDLINE]
119: Plast Reconstr Surg. 1996 Dec;98(7):1264-71, discussion 1272-4.
Sciatic function index, nerve conduction tests, muscle contraction, and axon
morphometry as indicators of regeneration.
Kanaya F, Firrell JC, Breidenbach WC.
Christine M. Kleinert Institute for Hand and Micro Surgery, Louisville,Ky., USA.
The purpose of this study was to determine which parameters were the best
measure of nerve regeneration, assuming that the sciatic functional index (SFI)
represented the "gold standard." Three different sciatic functional indexes and
11 commonly used electrophysiologic and morphologic indicators of regeneration
were all determined in 24 rats 12 weeks after one of three lesions was created
in the sciatic nerve. With linear regression analysis, only fiber/axon diameter
ratio (D/d) and myelin thickness/axon diameter ratio showed statistically
significant correlations with sciatic functional index (r = 0.55 and 0.53,
respectively). The other 11 parameters had poorer correlation. Therefore, if
sciatic functional index is the best measure of comprehensive nerve function,
then other parameters are not. It is probable that each parameter measures some
different component of the regeneration process. A stepwise multiple linear
regression analysis produced a model that included D/d, nerve conduction
velocity, and nerve action potential amplitude that gave a slightly better
correlation (r = 0.67). The relatively poor correlation between sciatic
functional index and the other parameters of nerve function indicates that all
nerve regeneration studies must be interpreted carefully before comparisons are
made. Furthermore, the best measure of nerve function remains unproved or
undiscovered in the experimental animal.
PMID: 8942915 [PubMed - indexed for MEDLINE]
120: Neurosci Lett. 1980 Nov;20(2):131-4.
Differential labeling by horseradish peroxidase of small and large spinal
neurons of rats.
Neuhuber W, Niederle B.
Solid horseradish peroxidase (HRP) was applied to the crushed peroneal nerves
of
rats and its retrograde transport to spinal ganglion cells and spinal
motoneurons was examined after varying survival times. Following short (22-39
h)
survival times predominantly small sensory and motoneuronal cell bodies
contained HRP. Following long intervals (72-96 h), the percentage of labeled
large cells increased in both groups of neurons. The differences were more
pronounced in sensory than in motoneurons.
PMID: 7443063 [PubMed - indexed for MEDLINE]
121: Restor Neurol Neurosci. 2000;17(1):39-44.
Acceleration of peripheral nerve regeneration following FK506 administration.
Jost SC, Doolabh VB, Mackinnon SE, Lee M, Hunter D.
Division of Plastic and Reconstructive Surgery, Washington University School of
Medicine.
Purpose: The severe functional and sensory deficits seen following injury to
peripheral nerves makes facilitation of nerve regeneration a primary goal of the
reconstructive surgeon. This study examines whether daily administration of
FK506 or Cyclosporin A expedites peripheral nerve regeneration following
neurotmetic injury in a rat model Methods: Inbred Buffalo rats were randomized
to three experimental groups. Group I rats served as untreated controls. Rats
in
groups II and III received daily subcutaneous CsA (5 mg/kg), and FK506 (1
mg/kg), respectively. Each animal underwent unilateral posterior tibial nerve
transection with immediate epineurial reapproximation. Functional recovery of
the injured limb was assessed by serial walking track analysis. Nerve
regeneration was assessed histomorphometrically via light microscopy. Results:
Return of hindlimb function in control animals occurred at 32 days post injury.
CsA and FK506-treated transection animals recovered at 26 and 18 days post
injury, respectively. Statistically significant greater fiber density and
percent neural tissue were seen in FK506- treated animals compared to control
animals four weeks post transection. Conclusions: This data suggest that the
daily systemic administration of both CsA and FK506 accelerate the rate of
functional regeneration, following neurotmetic injuries in tbc rat model.
FK506's effect on nerve growth is significantly greater than that of CsA.
PMID: 11490076 [PubMed - as supplied by publisher]
122: J Anat. 1999 Jan;194 ( Pt 1):1-14.
Peripheral nerve regeneration and neurotrophic factors.
Terenghi G.
Blond McIndoe Centre, Queen Victoria Hospital, East Grinstead, Sussex, UK.
terenghi@mcindoe.ucl.demon.co.uk
The role of neurotrophic factors in the maintenance and survival of peripheral
neuronal cells has been the subject of numerous studies. Administration of
exogenous neurotrophic factors after nerve injury has been shown to mimic the
effect of target organ-derived trophic factors on neuronal cells. After axotomy
and during peripheral nerve regeneration, the neurotrophins NGF, NT-3 and BDNF
show a well defined and selective beneficial effect on the survival and
phenotypic expression of primary sensory neurons in dorsal root ganglia and of
motoneurons in spinal cord. Other neurotrophic factors such as CNTF, GDNF and
LIF also exert a variety of actions on neuronal cells, which appear to overlap
and complement those of the neurotrophins. In addition, there is an indirect
contribution of GGF to nerve regeneration. GGF is produced by neurons and
stimulates proliferation of Schwann cells, underlining the close interaction
between neuronal and glial cells during peripheral nerve regeneration. Different
possibilities have been investigated for the delivery of growth factors to the
injured neurons, in search of a suitable system for clinical applications. The
studies reviewed in this article show the therapeutic potential of neurotrophic
factors for the treatment of peripheral nerve injury and for neuropathies.
Publication Types:
Review
Review, Academic
PMID: 10227662 [PubMed - indexed for MEDLINE]
123: Muscle Nerve. 1993 Dec;16(12):1302-9.
Comment in:
Muscle Nerve. 1994 Oct;17(10):1226-8.
F tacheodispersion: quantitative analysis of motor fiber conduction velocities
in patients with polyneuropathy.
Chroni E, Panayiotopoulos CP.
Department of Clinical Neurophysiology and Epilepsy, St. Thomas' Hospital,
London, United Kingdom.
The distribution of motor fiber conduction velocities (FCVs) of the ulnar and
peroneal nerves in patients with polyneuropathy was estimated using F
tacheodispersion, a technique based on F wave latencies. Twenty-three ulnar and
23 peroneal nerves were studied. Three groups of nerves were identified
according to conventional, M response, and F wave measurements: those with all
parameters normal (group 1), those with abnormal F wave parameters only (group
2), and those with all parameters abnormal (group 3). Application of F
tacheodispersion to nerves in group 1 revealed a shift of the distribution of
FCVs toward the lower normal values in 6 of 7 nerves. In group 2, a significant
proportion of FCVs were below the lower normal limits despite normal maximum
conduction velocity estimated by the M response. In group 3, all nerve fibers
were abnormally slow. The results indicate that application of F
tacheodispersion in clinical practice will increase sensitivity of nerve
conduction studies and enable quantitative estimation of conduction in a motor
nerve fiber population.
PMID: 8232385 [PubMed - indexed for MEDLINE]
124: Science. 1983 Jun 17;220(4603):1283-5.
Pulsing electromagnetic fields induce cellular transcription.
Goodman R, Bassett CA, Henderson AS.
Weak, pulsing electromagnetic fields can modify biological processes. The
hypothesis that responses to such induced currents depend on pulse
characteristics was evaluated by using transcription as the target process. Two
pulses in clinical use, the repetitive single pulse and the repetitive pulse
train, were tested. These pulses produced different results from each other and
from controls when transcription in dipteran salivary gland cells was monitored
with tritiated uridine in transcription autoradiography, cytological nick
translation, and analysis of isolated RNA fractions. The single pulse increased
the specific activity of messenger RNA after 15 and 45 minutes of exposure. The
pulse train increased specific activity only after 45 minutes of exposure.
PMID: 6857248 [PubMed - indexed for MEDLINE]
125: J Hand Surg [Br]. 1998 Oct;23(5):588-93.
Biodegradable controlled release glass in the repair of peripheral nerve
injuries.
Lenihan DV, Carter AJ, Gilchrist T, Healy DM, Miller IA, Myles LM, Glasby MA.
Department of Clinical Neuroscience, University of Edinburgh, Ayr, UK.
The experiments in this paper were concerned with the recovery of function and
ease of application of an entubulation technique using a biodegradable,
controlled release glass tube (CRG) for the repair of a transected peripheral
nerve. The peroneal nerves of 15 New Zealand White rabbits were repaired with
either a CRG tube filled with freeze-thawed muscle, or a conventional freeze
thawed muscle graft (FTMG). These were compared with controls in which a CRG was
used to enclose the cut ends of a nerve separated by a 1 cm gap.
Electrophysiological and morphometric assessment was carried out 6 months after
repair. No statistical difference was found in any test between the FTMG and the
CRG tube filled with freeze thawed muscle. The CRG tube and 1 cm gap produced
inferior levels of recovery of function when compared with the other two repair
groups.
PMID: 9821599 [PubMed - indexed for MEDLINE]
126: Rev Esp Fisiol. 1982 Sep;38(3):295-301.
[Effects of distal axotomy on field potentials of the external oculomotor
nucleus in the waking cat]
[Article in Spanish]
Serra R, Ribas J, Delgado-Garcia JM.
The electrophysiology of abducens nucleus antidromic field potentials from onset
of peripheral axotomy up to reinnervation has been studied in the alert cat.
Nerve section induced a reduction of 80% in the amplitude of the antidromic
field potential. This reduction began from 2 to 5 days after axotomy and
returned to control values from 20 to 30 days later, in parallel with recovery
of oculomotor function. During the critical chromatolytic period, the latency
of
the antidromic potentials increased, while the amplitude of the antidromic field
potential could be easily modified by adequate visual and/or vestibular
stimulation. In contrast to control motoneurons, axotomized cells showed a
noticeable variability in their activation latency, as well as a higher
threshold for the antidromic invasion of the IS-SD compartments.
PMID: 6984199 [PubMed - indexed for MEDLINE]
127: J Hand Surg [Am]. 1996 Mar;21(2):259-65.
Nerve coaptation studies with and without a gap in rabbits.
Hasegawa J, Shibata M, Takahashi H.
Department of Orthopaedic Surgery, Niigata University School of Medicine, Japan.
Appropriate matching of proximal and distal fibers is a major objective when
suturing a lacerated nerve. Recent studies suggest that neurotropic factors may
influence motor/sensory specificity and affect the functional outcome. This was
studied in animal models by direct coaptation of cut nerve ends inside a 5-mm
collagen tube with and without appropriate sensory/motor alignment, as well as
in models where the cut nerve ends were placed in a 10-mm collagen tube with a
5-mm gap, with and without appropriate sensory/motor alignment. The radial nerve
of 49 New Zealand white rabbits was chosen because it has distinct motor and
sensory divisions. The animals were killed at 24 weeks and electrophysiologic,
histologic, and muscle contraction studies were performed. Axon counts and
diameters were measured from the distal motor and sensory stumps. Nerve
conduction velocity, dry muscle weight, and motor axon counts were not
statistically different between the groups. The malaligned group without a gap
had better regeneration in sensory nerves than other groups. The muscle
contraction force of the malaligned group without a gap was significantly less
than the other groups. The malaligned group with a 5-mm gap had the same muscle
contraction force as the aligned group without a gap. In this study, a short
nerve gap lessened the misdirection of motor fibers after nerve-end coaptation.
PMID: 8683059 [PubMed - indexed for MEDLINE]
128: J Comp Neurol. 2002 Oct 21;452(3):255-63.
Differential effects of neurotrophins on neuronal survival and axonal
regeneration after spinal cord injury in adult rats.
Novikova LN, Novikov LN, Kellerth JO.
Department of Integrative Medical Biology, Section of Anatomy, Umea University,
SE-901 87 Umea, Sweden.
Spinal cord injury (SCI) induces retrograde cell death in descending pathways,
which can be prevented by long-term intrathecal infusion of neurotrophins
(Novikova et al. [2000] Eur J Neurosci 12:776-780). The present study
investigates whether the same treatment also leads to improved regeneration of
the injured tracts. After cervical SCI in adult rats, a peripheral nerve graft
was attached to the rostral wall of the lesion cavity. The animals were treated
by local application into the cavity of Gelfoam soaked in (1) phosphate buffered
saline (untreated controls) or (2) a mixture of the neurotrophins brain-derived
neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) (local treatment), or by
intrathecal infusion of BDNF + NT-3 for (3) 2 weeks (short-term treatment) or
(4) 5-8 weeks (long-term treatment). Despite a very strong survival effect,
long-term treatment failed to stimulate ingrowth of descending tracts into the
nerve graft. In comparison with untreated controls, the latter treatment also
caused 35% reduction in axonal sprouting of descending pathways rostral to the
lesion site and 72% reduction in the number of spinal cord neurons extending
axons into the nerve graft. Local and short-term treatments neither prevented
retrograde cell death nor enhanced regeneration of descending tracts, but
induced robust regeneration of spinal cord neurons into the nerve graft. These
results indicate that the signal pathways promoting neuronal survival and axonal
regeneration, respectively, in descending tracts after SCI respond differently
to neurotrophic stimuli and that efficient rescue of axotomized tract neurons
is
not a sufficient prerequisite for regeneration. Copyright 2002 Wiley-Liss, Inc.
PMID: 12353221 [PubMed - indexed for MEDLINE]
129: Electromyogr Clin Neurophysiol. 2001 Jul-Aug;41(5):269-71.
The changes in the transmission functioning of the ulnar nerve in a high power
magnetic field.
Mansouri B, Pakdaman H, Yassami S, Karimzadeh A.
Shaheed Beheshti University of Medical Sciences, Thran, Islamic Republic of
Iran. bmansouri@in-box.net
INTRODUCTION: The present study aims at exploring the changes in the functioning
of the ulnar nerve in a high power magnetic field. METHODS: 12 volunteers with
a
healthy peripheral nervous system participated in the study. The ulnar nerve was
selected from the upper organs as the site for study. The functioning of both
the sensory and motor parts of the ulnar nerve in normal conditions was
electromyographically tested. Then, using the same setting, the functioning of
the nerve was electromyographically tested within a high power magnetic field
(0.2 Tesla). With regard to the sensory function, the distal latency and the
amplitude were examined. With regard to the motor section, the duration,
amplitude of the evoked potentials, and latency from two sites--distal and
proximal--were examined. These results of the two readings, taken in normal
condition and in a high power magnetic field, as well as the motor neural
conduction velocity, were compared. RESULTS: The statistical analyses indicated
that the changes in both the distal latency and amplitude of the sensory part
of
the ulnar nerve were significant. However, the changes in the motor function of
the nerve were not significant.
PMID: 11572187 [PubMed - indexed for MEDLINE]
130: Laryngoscope. 1996 May;106(5 Pt 1):629-32.
Brain-derived neurotrophic factor and peripheral nerve regeneration: a
functional evaluation.
Shirley DM, Williams SA, Santos PM.
Division of Otolaryngology, Southern Illinois University, Springfield, 62794,
USA.
The potential benefit of brain-derived neurotrophic factor (BDNF) on motor-nerve
regeneration after transection injury in 24 adult rats was evaluated after
entubulation repair. Gait analysis for ankle angle and tension transduction
device (TTD) strain-gauge measurements yielded functional evaluation of
regeneration. The BDNF (15 mg/mL) or phosphate buffered saline (control) was
injected into the silicone elastomer (Silastic) channel. Gait analysis performed
0, 2, 4, 6, 10, and 12 weeks after injury demonstrated a significant difference
between uninjured and injured legs of 23 and 43 degrees, respectively (P<.001,
analysis of variance). The TTD evaluation 13 weeks after injury demonstrated a
significant decrease in force development of injured compared to uninjured legs,
148 and 58 g, respectively (P<.001). No functional benefits were demonstrated
between BDNF-treated versus control-treated animals in either model for a single
exposure to BDNF.
PMID: 8628094 [PubMed - indexed for MEDLINE]
131: Arch Neurol. 2002 Sep;59(9):1430-6.
Impairment of the peripheral nervous system in Creutzfeldt-Jakob disease.
Niewiadomska M, Kulczycki J, Wochnik-Dyjas D, Szpak GM, Rakowicz M, Lojkowska
W,
Niedzielska K, Inglot E, Wieclawska M, Glazowski C, Tarnowska-Dziduszko E.
Department of Clinical Neurophysiology, Institute of Psychiatry and Neurology,
9
Sobieskiego, 02-957 Warsaw, Poland. niewiad@ipin-edu.pl
BACKGROUND: The clinical manifestations of Creutzfeldt-Jakob disease (CJD)
primarily reflect involvement of the central nervous system. The coexistence of
CJD with peripheral nervous system involvement has also been reported.
OBJECTIVE: To analyze peripheral neuron electrophysiologic changes and to
compare these data with neuropathologic features of spinal motor neurons in
patients with definite CJD. DESIGN AND PATIENTS: Electrophysiologic examinations
were performed on 16 patients with sporadic CJD. The diagnosis was confirmed by
neuropathologic examinations (15 patients) or by intravital detection of the
14-3-3 protein in the cerebrospinal fluid (1 patient). The spinal cord was
neuropathologically examined in 8 patients. SETTING: Department of Clinical
Neurophysiology, I Neurological Department, Institute of Psychiatry and
Neurology, Warsaw, Poland. MAIN OUTCOME MEASURES: Electromyography, compound
muscle and sensory nerve action potentials, distal latencies, F waves,
peripheral motor and sensory conduction velocity, and spinal motor neuron
numbers and morphologic characteristics. RESULTS: All patients had signs of
central nervous system damage typical of sporadic CJD. Only 3 patients had
clinical signs of peripheral nervous system involvement. Electrophysiologic
examinations confirmed peripheral nervous system damage in these patients and
revealed preclinical peripheral nervous system impairment in 11 more patients.
In 1 patient, electrophysiologic examination revealed features of motor neuron
disease; in 9, axonal disease; and in 4, axonal-demyelinating neuropathy.
Neuropathologic examination results confirmed severe loss of spinal motor
neurons in 1 patient with motor neuron disease and revealed the features of
motor neuron chronic disease in 4. In 2 of them, electrophysiologic data were
normal. CONCLUSION: In sporadic cases of CJD, peripheral nervous system
impairment should be considered to be an integral component of disease.
Publication Types:
Clinical Trial
PMID: 12223030 [PubMed - indexed for MEDLINE]
132: Acta Acad Med Wuhan. 1984;4(4):220-8.
Preliminary report on experimental observation of the effects of magnetic field
and "Natural Copper" on fracture healing.
Liu HQ, Zhu X, Zhao SL, Yu M, Meng XM.
PMID: 6527846 [PubMed - indexed for MEDLINE]
133: J Spinal Cord Med. 1999 Winter;22(4):287-96.
FK506 increases the regeneration of spinal cord axons in a predegenerated
peripheral nerve autograft.
Wang MS, Gold BG.
Center for Research on Occupational and Environmental Toxicology, Oregon Health
Sciences University, Portland 97201-3098, USA.
The authors examined the ability of FK506 to accelerate axonal regeneration of
rat spinal cord axons in a peripheral nerve (PN) graft. Predegenerated
autografts were produced by transecting the left tibial nerve 1 week prior to
spinal cord implantation into the lumbar (L-3-L-4) spinal cord. Rats were given
daily injections of either FK506 (5 mg/kg, subcutaneous) or vehicle for 21 days.
The PN grafts from FK506-treated rats contained larger sized regenerating axons
compared with vehicle-treated controls, and mean axonal areas increased by 25%
at 7.5 mm along the PN graft. Fluoro-Gold retrograde labeling confirmed that the
regenerating axons originated from the central nervous system. Unexpectedly, the
majority (>50%) of neurons in the red nucleus were retrogradely labeled in
the
FK506-treated animals only. The results indicate that FK506 not only accelerates
the elongation of spinal cord axons but also promotes regeneration of
rubrospinal neurons.
PMID: 10751133 [PubMed - indexed for MEDLINE]
134: J Orthop Res. 1990 Sep;8(5):685-93.
Electromagnetic effects on bone formation at implants in the medullary canal in
rabbits.
Spadaro JA, Albanese SA, Chase SE.
Department of Orthopedic Surgery, S.U.N.Y.-HSC, Syracuse 13210.
This experiment was aimed at illuminating the relationship between
electromagnetic and mechanical stimuli of bone formation when present
simultaneously. Movable and stationary intramedullary wire implants were studied
in rabbits treated with a pulsing electromagnetic field (PEMF) 4 h/day for 3
weeks, and were compared with identical control animals without PEMF. Trabecular
bone formed routinely at spontaneously movable implants, but not at stationary
ones. On average, PEMF-treated movable implants in the femur induced 44% more
bone than untreated movable implants. Also, in the PEMF-treated femora, a 22%
enlargement of the area of the medullary canal was observed compared with
no-field controls. In the tibia, these effects were weak or nonexistent. The
PEMF used did not induce bone at stationary implants, suggesting that under
these conditions it is not a primary trigger in vivo.
PMID: 2388108 [PubMed - indexed for MEDLINE]
135: Clin Orthop. 1977 May;(124):128-43.
A non-operative salvage of surgically-resistant pseudarthroses and non-unions
by
pulsing electromagnetic fields. A preliminary report.
Bassett CA, Pilla AA, Pawluk RJ.
This report documents, for the first time, to the authors' knowledge, the
therapeutic use in humans of low energy, electromagnetic fields pulsing in the
extremely low frequency (E.L.F.) range. These fields, established outside the
body, were used to treat congenital and acquired pseudarthroses and non-unions.
Energy of this type appears to affect biological processes, not through heat
production, but through electrically-induced changes in the environment of cells
within the organism. Of the 29 patients included in the study, 17 had
experienced at least one failure of surgical repair and, in each of these,
amputation had been recommended. The overall success rate, including those
patients treated with inadequate pulse characteristics and those who failed to
follow the protocol, was in excess of 70 per cent. Improvements in the
specificity of pulse characteristics hold promise for increasing the rate of
success. The simple, clinical methodology, which is conducted on an out-patient
basis, appears to be both safe and effective. It can be applied with or without
surgery. This approach requires additional controlled investigations before it
is ready for general use in the orthopaedic community. The indications for
amputation of surgically-resistant pseudarthroses, however, should be
reassessed. The principles and technology, which have been established during
this endeavor, may have physiologic and practical significance for processes
other than pseudarthrosis and non-union.
PMID: 598067 [PubMed - indexed for MEDLINE]
136: Prog Clin Biol Res. 1986;210:239-50.
The role of natural and applied electric fields in neuronal regeneration and
development.
Borgens RB.
PMID: 3960913 [PubMed - indexed for MEDLINE]
137: Fiziol Zh. 2003;49(2):85-90.
[Use of low-power electromagnetic therapy in diabetic polyneuropathy]
[Article in Ukrainian]
Chebotar'ova LL, Chebotar'ov HIe.
The clinical-electroneuromyography investigations were performed for objective
evaluation of low-power electromagnetic therapy effectiveness in 12 patients
with diabetic polyneuropaties. It is established that combination of low-power
electromagnetic therapy using "ANET-UHF", "ANET-SHF" apparatus (Ukraine) and
low-power variable magnetic field using AMT apparatus (Ukraine) give the stable
positive effects. The positive changes were confirmed by following: the decrease
of neurological deficit and required insulin daily dose, nerve conduction
velocity increase, increase of the muscle compound action potentials (muscle
power) and peripheral outflow in some patients.
Publication Types:
Evaluation Studies
PMID: 12945120 [PubMed - indexed for MEDLINE]
138: J Orthop Res. 1991 Nov;9(6):908-17.
Electromagnetic stimulation of bone repair: a histomorphometric study.
Cane V, Botti P, Farneti D, Soana S.
Institutes of Human Anatomy, University of Modena, Italy.
The effect of pulsing electromagnetic fields (PEMFs) on bone repair was studied
in principal metacarpal bones of eight adult male horses: Six horses were
treated with PEMFs, and two horses were untreated. In treated horses, Helmholtz
coils were applied during a 60-day period to the left metacarpal bones, bored
with eight holes of equal diameter and depth, from the middiaphysis toward the
distal metaphysis. Eight equal holes bored in the right metacarpal, surrounded
by unactivated Helmholtz coils, were taken as controls. The two untreated horses
were taken as additional control. The results of computer-assisted
histomorphometric analysis indicate that (a) in diaphyseal levels, the amount
of
bone formed during 60 days is significantly greater (p less than 0.01) in
PEMF-treated holes than in contralateral ones and those in control horses; (b)
in metaphyseal levels, PEMF-treated holes are sometimes more closed, sometimes
less, as compared with contralateral holes and those in control horses; in any
case the statistical analysis indicates that the symmetry in the rate of hole
repair, found between the two antimeres of control horses, is not appreciable
at
metaphyseal levels also; (c) there was no statistically significant difference
between untreated holes in PEMF-treated horses and holes in control horses,
neither at diaphyseal nor at metaphyseal levels. These preliminary findings
indicate that PEMFs at low frequency influence the process of bone repair on
both diaphysis and metaphysis, and seem to improve the process of bone repair
in
skeletal regions normally having a lower osteogenetic activity, i.e., in
diaphyses as against metaphyses.
PMID: 1919855 [PubMed - indexed for MEDLINE]
139: Exp Brain Res. 1988;71(1):223-6.
Treatment of the damaged rat hippocampus with a locally applied electric field.
Politis MJ, Zanakis MF.
Department of Anatomy, University of Saskatchewan, Saskatoon, Canada.
Previous studies have indicated that axons may be directed to regenerate toward
the cathodal source of a locally applied D.C. electric field. In the present
studies, similar galvanotropic effects were tested after partial denervation of
the rat hippocampus. Following unilateral fimbrial lesions, 1.5 microA of direct
current was applied locally to the tissue for 4 weeks. In the experimental
group, the distal (temporal) portion of the hippocampus was located near the
cathodal electrode, while the proximal (nasal) portion was located near the
anode. In two control groups, either the current was reversed, or there was not
current delivered to the tissue. Spontaneous alternation behavior 4 weeks
post-operatively in the "cathode distal" rats provided results comparable to
those in unoperated (normal) animals, whereas the control animals exhibited
statistically significantly greater deficits in memory. The ability to learn the
location of a submerged platform in a water tank was evident in unoperated and
"cathode distal" animals, but not in either of the control groups. Hippocampal
acetylcholinesterase activity in "cathode distal" animals was lower than in
unoperated animals, but statistically significantly greater than in the other
control animals. Results are consistent with the contention that locally applied
weak direct current can modulate long term sequellae of hippocampal injury.
PMID: 3416955 [PubMed - indexed for MEDLINE]
140: Vopr Kurortol Fizioter Lech Fiz Kult. 1984 May-Jun;(3):19-23.
[Effect of interference current and low-frequency magnetic field on tissue
regeneration]
[Article in Russian]
Nikolova L, Popov A, Klouchek E.
PMID: 6332416 [PubMed - indexed for MEDLINE]
141: Equine Vet J. 1987 Mar;19(2):120-4.
Preliminary study of quantitative aspects and the effect of pulsed
electromagnetic field treatment on the incorporation of equine cancellous bone
grafts.
Kold SE, Hickman J, Meisen F.
The quantitative aspects of equine cancellous bone graft incorporation and the
possibility of influencing graft incorporation by daily exposure to a pulsed
electromagnetic field (PEMF) was studied in eight yearling ponies. In order to
be able to quantify formative aspects of graft remodelling, a double and treble
tetracycline intravital labelling technique was used. Intravital radiographs
were obtained at regular intervals throughout the trial, but were found to be
of
little assistance in assessing any differences between stimulated and
non-stimulated grafts. The ponies were humanely destroyed at regular intervals
between nine and 241 days after installation of the graft. Light microscopy and
fluorescent light microscopy were used to evaluate quantitative aspects of graft
incorporation and to compare PEMF-stimulated grafts with control grafts. There
was a small but statistically significant effect of PEMF-stimulation on
cancellous bone graft incorporation. In view of this, these observations can
only be considered as indicative of a possible trend, but should encourage
further studies using different signal modalities.
PMID: 3552658 [PubMed - indexed for MEDLINE]
142: Vestn Dermatol Venerol. 1987;(3):56-8.
[Use of an electromagnetic field and iodine-bromine baths in the complex
treatment of patients with circumscribed scleroderma]
[Article in Russian]
Aleksaniants GD.
PMID: 3604436 [PubMed - indexed for MEDLINE]
143: Chir Narzadow Ruchu Ortop Pol. 1987;52(6):463-8.
[Morphological and morphometric studies of the healing of an experimental
musculo-cutaneous wound after its exposure to a constant electromagnetic field]
[Article in Polish]
Szram S, Bielnik K, Sondej J.
PMID: 3452501 [PubMed - indexed for MEDLINE]
144: Vestn Otorinolaringol. 1988 May-Jun;(3):42-7.
[Use of a low-frequency alternating magnetic field in the complex treatment of
patients with functional diseases of the larynx]
[Article in Russian]
Demchenko EV.
PMID: 3212866 [PubMed - indexed for MEDLINE]
145: Revmatologiia (Mosk). 1987 Jul-Sep;(3):40-4.
[Reflexotherapy of osteoarthritis patients using the action of a UHF
electromagnetic field]
[Article in Russian]
Galkina MG, Shargorodskaia DV, Roshchina NA.
Publication Types:
Case Reports
PMID: 3317712 [PubMed - indexed for MEDLINE]
146: Sov Med. 1983;(5):35-8.
[Use of the electromagnetic field in patients after disturbance of cerebral
circulation]
[Article in Russian]
Strelkova NI, Maslovskaia SG, Gavrilkov AG, Strel'tsova EN.
PMID: 6612459 [PubMed - indexed for MEDLINE]
147: Lancet. 1984 Jul 21;2(8395):171-2.
Pulsed magnetic field therapy for tibial non-union.
O'Connor BT.
Publication Types:
Letter
PMID: 6146073 [PubMed - indexed for MEDLINE]
148: Patol Fiziol Eksp Ter. 1986 Sep-Oct;(5):74-7.
[Characteristics of the course of experimental arthritis after bitemporal
exposure to an ultrahigh-frequency electric field]
[Article in Russian]
Ponomarev VD, Bogoliubov VM, Frenkel' ID, Pershin SB, Ponomarev IuT.
PMID: 3797098 [PubMed - indexed for MEDLINE]
149: Experientia. 1975 Dec 15;31(12):1411-2.
Effects of magnetic field on inflammation.
Mizushima Y, Akaoka I, Nishida Y.
The effects of a 50 Hz magnetic field on experimentally-induced inflammation in
rats were studied. Carrageenan edema was inhibited significantly by exposure to
magnetic field for 3 h. Adjuvant-induced arthritis in rats was also suppressed
by the magnetic field.
PMID: 1213056 [PubMed - indexed for MEDLINE]
150: Med Radiol (Mosk). 1979 Sep;24(9):9-12.
[Prospects for using local UHF-hyperthermia combined with radiation therapy for
malignant tumors]
[Article in Russian]
Lopatin VF, Dedenkov AN.
PMID: 502796 [PubMed - indexed for MEDLINE]
151: Vestn Khir Im I I Grek. 1986 Sep;137(9):87-8.
[Effect of a constant magnetic field on blood circulation after experimental
operations on arteries of the extremities]
[Article in Russian]
Lud GV.
PMID: 3538626 [PubMed - indexed for MEDLINE]
152: Ugeskr Laeger. 1987 Dec 21;149(52):3523-5.
[Dynamic electromagnetic fields--possible clinical use]
[Article in Danish]
Gregersen H.
PMID: 3433567 [PubMed - indexed for MEDLINE]
153: Vopr Kurortol Fizioter Lech Fiz Kult. 1984 May-Jun;(3):31-4.
[Treatment of patients with chronic nonspecific respiratory diseases with
decimeter-range electromagnetic field and pyrogenal]
[Article in Russian]
Sheina AN, Grigor'eva VD, Mitrofanova GF, Shishlo MA.
PMID: 6474921 [PubMed - indexed for MEDLINE]
154: Vopr Kurortol Fizioter Lech Fiz Kult. 1985 Jan-Feb;(1):40-3.
[Effectiveness of pulsating magnetic fields in patients with disorders of spinal
cord circulation based on data of global and stimulating electromyography]
[Article in Russian]
Musaev AV.
PMID: 3984252 [PubMed - indexed for MEDLINE]
155: Vopr Kurortol Fizioter Lech Fiz Kult. 1984 Sep-Oct;(5):54-5.
[Effect of a low-frequency alternating magnetic field on the course of
pyrogenal-induced fever]
[Article in Russian]
Shishlo MA, Nikulina LA, Kirichenko NB.
PMID: 6506567 [PubMed - indexed for MEDLINE]
156: Iyodenshi To Seitai Kogaku. 1974 Dec;12(6):341-9.
[Electromagnetic field and biological systems]
[Article in Japanese]
Saito M, Yamaura I.
Publication Types:
Review
PMID: 4619635 [PubMed - indexed for MEDLINE]
157: Z Exp Angew Psychol. 1977;24(3):397-412.
[Effect of an artificial electro-climate on physiological and psychological
parameters]
[Article in German]
Fischer G, Strampfer H, Riedl H.
PMID: 906579 [PubMed - indexed for MEDLINE]
158: Fortschr Med. 1988 Apr 20;106(12):76-7.
[Magnetic field therapy: legal tricks instead of effectiveness. Controversial
tactics of the federal health society--current availability blocks
decision--financial stress for health insurance]
[Article in German]
Schwing C.
PMID: 3135257 [PubMed - indexed for MEDLINE]
159: Biofizika. 1985 Nov-Dec;30(6):1046-9.
[Effect of weak alternating ultra-low frequency magnetic fields on the
development of the hypercoagulation syndrome in immobilized rats]
[Article in Russian]
Temur'iants NA, Mikhailov AV.
The experimental results are given concerning the effect of variable magnetic
field (VMF) with the frequency of 8 Hz and intensity 4 A/m on some parameters
of
rat haemocoagulation system under standard mobile regime as well as under
prolonged hypokinesia. It is stated that repeated daily exposition of VMF causes
hypocoagulational blood shift in intact animals. Under the effect of
simultaneous VMF and hypokinesia the correction of hypercoagulational shift
induced by animal hypokinesia was detected. The highest VMF effect was observed
in prolonged experiments. A conclusion is drawn concerning the ability of VMF
with the given parameters to limit the development of rat blood hypercoagulation
under hypokinesia.
PMID: 4074760 [PubMed - indexed for MEDLINE]
160: Biull Eksp Biol Med. 1983 May;95(5):62-4.
[Effect of an electromagnetic field on conditioned reflex maintenance and the
nucleic acid content of brain tissues during carotid artery constriction]
[Article in Russian]
Rutsai SV, Surkova IS.
It has been discovered in chronic experiments on 54 rats that during ligation
of
the carotid artery, the action of the decimetric electromagnetic field
(DMB-irradiation) produces in some cases the deterioration of the rats' status
that manifests in paroxysms eventuating in lethal outcomes, whereas in other
ones, makes the conditioned reflexes return to normal, accompanied by an
increase in RNA content in the cortex of the large hemispheres. The mechanisms
of an inconclusive action of DMB-irradiation is discussed as is the importance
of changes in RNA content in the cortex for the mechanisms of a favourable
action of irradiation on the recovery of brain function in circulatory
disorders. The possibilities of using DMB-irradiation under the clinical
conditions are also discussed.
PMID: 6189533 [PubMed - indexed for MEDLINE]
161: Akush Ginekol (Mosk). 1983 Sep;(9):55-7.
[Use of a weak acoustic-frequency magnetic field in the complex treatment of
diseases of the internal genital organs of women]
[Article in Russian]
Mel'nikova MM, Kunitsyna GA, Toroptsev ND.
Publication Types:
Review
PMID: 6359931 [PubMed - indexed for MEDLINE]
162: Vopr Kurortol Fizioter Lech Fiz Kult. 1985 Jan-Feb;(1):23-7.
[Hemodynamic and humoral mechanisms of the therapeutic effect of the
"travelling" impulse magnetic field in hypertension]
[Article in Russian]
Orlov LL, Alekseeva NP, Galuza GI, Slutskii II, Drozdov IuF.
PMID: 3984249 [PubMed - indexed for MEDLINE]
163: Recenti Prog Med. 1983 Sep;74(9):1090-2.
[Magnetotherapy]
[Article in Italian]
Ferrari M, Piro MT.
PMID: 6658172 [PubMed - indexed for MEDLINE]
164: Ann Med Psychol (Paris). 1985 Mar;143(3):235-54.
[Th importance of spectral analysis in the evaluation of the effects of magnetic
pulsed fields on alpha rhythm]
[Article in French]
Levillain D, Picat J.
By means of spectral analysis, this research of alpha rhythm's modifications
upon effects of electromagnetic fields makes conspicuous an increasing frequency
and amplitude of this rhythm, proportionally to the time passage, and proposes
questions and interpretations.
PMID: 4051371 [PubMed - indexed for MEDLINE]
165: Cas Lek Cesk. 1987 Mar 27;126(13):405-9.
[Modern views on the evaluation of the therapeutic use of magnetic fields]
[Article in Czech]
Grunner O.
PMID: 3581134 [PubMed - indexed for MEDLINE]
166: J Biomed Eng. 1983 Oct;5(4):336-9.
A variable pulse-burst electromagnetic generator for electrical stimulation of
biological systems.
Reddy GN, Saha S.
A variable frequency-burst type, electromagnetic pulse generator has been
developed to optimize the effect of electrical stimulation on bone growth. Using
a pair of coils, with 100 turns and 18-gauge wire, the instrument can generate
a
maximum magnetic field of 300 Gauss. Its pulse repetition frequency can be
varied from 10 Hz to 2 KHz and the duty cycle, consisting of several short
carrier frequency pulses, can be varied up to 95%. This design also permits the
period of the carrier pulse to be changed.
PMID: 6632846 [PubMed - indexed for MEDLINE]
167: Arkh Anat Gistol Embriol. 1985 Jul;89(7):5-10.
[Ultrastructure of cells of the lateral field of the hypothalamus of the cat
after exposure to electromagnetic radiation]
[Article in Russian]
Medvedeva MV, Kucherenko RP, Usova IP, Suvorov NB, Ur'iash VV.
Under the effect of electromagnetic radiation not any specific changes are
revealed in the neural system unequivocally characterizing disturbances in its
structure as a result of an excess absorption of electromagnetic energy. The
ultrastructural changes revealed in the lateral fields of the cat hypothalamus
are suitable for a well known scheme demonstrating the course of the
pathological process, where three phases are distinguished: reactive,
destructive and restorative. The pathological process develops gradually. The
reactive changes in neurons and synapses, observed immediately after withdrawal
of the electromagnetic action. increase during the following three months and
result in coarse destructive disorders and in death of some neurons and
synapses. In 6 months certain signs of restoration of the structures are
observed. Under the effect of electromagnetic radiation water redistribution
between the structures takes place, the sympathetic terminals loosing their
fluid. Thus, certain conditions are produced for sticking together the synaptic
vesicles. Possibly that deficiency of Ca++ ions contributes to it.
PMID: 4051778 [PubMed - indexed for MEDLINE]
168: Vopr Kurortol Fizioter Lech Fiz Kult. 1977 Nov-Dec;(6):71-7.
[Structure of the electromagnetic fields of the radiation emitters for the
decimeter wave therapy]
[Article in Russian]
Balakireva VN, Malyshev VL, Skurikhina LA.
PMID: 605524 [PubMed - indexed for MEDLINE]
169: Biofizika. 1988 Sep-Oct;33(5):841-4.
[Effect of electromagnetic fields on movement of microorganisms]
[Article in Russian]
Zel'nichenko AT, Koval'chuk VS, Posudin IuI.
Relationships between the motor activity and orientation of microorganisms and
parameters of the electromagnetic field and of the microorganisms themselves
were investigated. It has been shown that the type of microorganism and field
amplitude produces the strongest influence on the behaviour of microorganisms
in
the fields. Theoretical relationships of the value of rotating moment and the
field parameters, microorganism and environment were obtained. The results of
the experiments well agree with the theory.
PMID: 3224110 [PubMed - indexed for MEDLINE]
170: J Biomed Eng. 1984 Oct;6(4):293-6.
A device for generation of electromagnetic fields of extremely low frequency.
Wahlstrom O, Knutsson H.
A new device for generation of electromagnetic fields at extra low frequencies,
to be used in fracture treatment, is described. The device involves a coil and
a
battery powered noise-generator. An alternating magnetic field of 4 X 10(-4) T
(4 Gauss) (RMS value) with a frequency range 1-1000 Hz is generated. Results
from a controlled randomized study of fresh fractures have shown significant
differences (p less than 0.01) between the treated group and the control group.
The results are encouraging and motivate further investigations with this
method.
Publication Types:
Clinical Trial
Randomized Controlled Trial
PMID: 6503256 [PubMed - indexed for MEDLINE]
171: Acta Orthop Belg. 1978 Sep-Oct;44(5):636-50.
Cell behaviour and DNA modification in pulsing electromagnetic fields.
Hinsenkamp M, Chiabrera A, Ryaby J, Pilla AA, Bassett CA.
PMID: 753067 [PubMed - indexed for MEDLINE]
172: Arch Surg. 1974 Sep;109(3):420-5.
Regeneration of the vascular system in experimental peripheral nerve grafting.
Hirasawa Y, Morotomi T, Fujii T, Oda R, Nakatani K.
PMID: 4854062 [PubMed - indexed for MEDLINE]
173: Cas Lek Cesk. 1979 Oct 12;118(40-41):1221-6.
[Electromagnetic field and psychobiological information (author's transl)]
[Article in Czech]
Grunner O.
PMID: 526997 [PubMed - indexed for MEDLINE]
174: Panminerva Med. 1989 Oct-Dec;31(4):151-65.
On the electro-magnetic nature of life.
Jacobson JI.
Man has wondered since the dawning of thought about the origin and the meaning
of the spark of life. How does life work and what is the difference between life
and non-life? This paper wonders about the part that electromagnetism plays in
the life process. It proposes a new insight into the relation of in vivo
electromagnetic fields and gravitational fields and discusses such
manifestations as solitons, the quantum hall effect, gravity waves, biological
strings, biologically closed electric circuits, phonos and the piezoelectric
nature of living tissue. It proposes a new and fundamental form of resonance,
called Jacobson resonance. The system unifies quantum genetic characters and
associated structures with electromagnetic field interaction energies. The
result is the reorientation of atomic crystal lattice structures of organic
molecules critical to the sustenance of life. A new treatment methodology is
proposed for genomic, viral and trophic factor disorders essentially in terms
of
the potential efficacy of the magnetic force to reorient the spin angular
momenta of electrons and protons; to therein rearrange atomic and molecular
magnetic domains regulating homeostasis on microscopic, mesosopic and
macroscopic levels through biological amplification of quantum interactions.
Finally it proposes that the equation, mc2 = Bvl coulomb, may indeed represent
the achievement of fourfold physical unification, the unification of physics and
medicine, and resultant production of a thorough understanding of what may be
the most fundamental natural law of the universe representing the ultimate goal
of Einsteinian equivalence and relativistic field theory.