We've followed Professor Anninos' research since summer 2000 and recently, happened to meet 4 person's who had been to see Professor Anninos in Greece. We've talked at length and seen video tape of the electromagnetic field therapy process used upon dozens of his patients. If you've got Parkinson's disease, MS, Epilepsy, migraine headache, cluster headache, ADD, ADHD, or suffer with depression and can afford the time and expense of travel, we HIGHLY recommend you see them for picoTesla electromagnetic field therapy.We can assist your participation in the next electromagnetic field therapy 'excursion' to Greece; just email us; the IABC contact we've got will be glad to send you out information which will probably convince you that a trip to Greece for electromagnetic field therapy is worth the time and expense. See IABC press release on Professor Anninos.
EarthPulse™ has discovered that our patent pending magnetic field supplementation device and methods substantially enhance human (and animal) performance.
Usefulness of magnetic motor evoked potentials
in the surgical treatment of hemiplegic patients with intractable epilepsy.
KAMIDA T, BABA H, ONO K, YONEKURA M, FUJIKI M, KOBAYASHI H.
Department of Neurosurgery, Oita Medical University, 1-1 Idaigaoka, Hasama-machi,
879-55, Oita, Japan
Five hemiplegic patients with intractable epilepsy were studied with transcranial
magnetic stimulation (TMS) before and after various surgical treatments. These
patients had unilateral widespread cerebral lesions acquired at various times,
including congenital, infantile and childhood injury. Motor evoked potentials
(MEPs) of the abductor pollicis brevis (APB) muscles were simultaneously recorded
on both sides following TMS of the motor cortex in the respective hemisphere
using a figure-8 or circular coil. In all patients with congenital disease,
the abolition of motor function in the affected hemisphere was estimated by
magnetic MEPs, and the hemiplegia did not deteriorate after functional hemispherectomy
(HS) was performed in two of them. In two patients with acquired disease, HS
was not performed because it was shown by magnetic maps that the motor function
in the affected hemisphere remained. Furthermore, it was shown by electric MEPs
using subdural electrodes that a patient who had had encephalitis in early childhood
had a reorganised motor area in the parietal cortex of the affected hemisphere.
The present findings indicate that magnetic MEPs are a very useful non-invasive
method of assessing whether the motor area in the affected hemisphere can be
resected in hemiplegic patients with intractable epilepsy.
PMID: 12915083 [PubMed - as supplied by publisher]
------------------------------------------------------------------------
2: Nervenarzt. 2003 Aug;74(8):664-76. Related Articles, Links
[In Process Citation]
[Article in German]
Kellinghaus C, Loddenkemper T, Moddel G, Tergau F, Luders J, Ludemann P, Nair
DR, Luders HO.
Dept. of Neurology, The Cleveland Clinic Foundation, Cleveland, Ohio, USA,
Attempts to control epileptic seizures by electrical brain stimulation have
been performed for 50 years. Many different stimulation targets and methods
have been investigated. Vagal nerve stimulation (VNS) is now approved for the
treatment of refractory epilepsies by several governmental authorities in Europe
and North America. However, it is mainly used as a palliative method when patients
do not respond to medical treatment and epilepsy surgery is not possible. Numerous
studies of the effect of deep brain stimulation (DBS) on epileptic seizures
have been performed and almost invariably report remarkable success. However,
a limited number of controlled studies failed to show a significant effect.
Repetitive transcranial magnetic stimulation (rTMS) also was effective in open
studies, and controlled studies are now being carried out. In addition, several
uncontrolled reports describe successful treatment of refractory status epilepticus
with electroconvulsive therapy (ECT). In summary, with the targets and stimulation
parameters investigated so far, the effects of electrical brain stimulation
on seizure frequency have been moderate at best. In the animal laboratory, we
are now testing high-intensity, low-frequency stimulation of white matter tracts
directly connected to the epileptogenic zone (e.g., fornix, corpus callosum)
as a new methodology to increase the efficacy of DBS ("overdrive method").
PMID: 12904868 [PubMed - in process]
------------------------------------------------------------------------
3: Epilepsy Behav. 2003 Aug;4(4):375-85. Related Articles, Links
Neurophysiologic correlates of psychiatric disorders
and potential applications in epilepsy.
Halford JJ.
Department of Medicine, Neurology Division, Box 3678, Duke University Medical
Center, Durham, NC 27710, USA.
There is increasing interest in psychiatric assessment using neurophysiologic
tools such as electroencephalography (EEG), magnetoencephalography (MEG), and
transcranial magnetic stimulation (TMS). This is because these technologies
have good temporal resolution, are relatively noninvasive, and (with the exception
of MEG) are economical. Many different experimental paradigms and analysis techniques
for the assessment of psychiatric patients involving these technologies are
reviewed including conventional quantitative electroencephalography (QEEG),
EEG cordance, low-resolution electromagnetic tomography (LORETA), frontal midline
theta, midlatency auditory evoked potentials (P50, N100, P300), loudness dependency
of the auditory evoked potential (LDAEP), mismatch negativity (MMN), contingent
negative variation (CNV), and transcranial magnetic stimulation (TMS). Many
of these neurophysiologic stimulus paradigms hold the promise of improving psychiatric
patient care by improving diagnostic precision, predicting treatment response,
and providing new phenotypes for genetic studies. Large cooperative multisite
studies need to be designed to test and validate a few of these paradigms so
that they might find use in routine clinical practice.
PMID: 12899857 [PubMed - in process]
------------------------------------------------------------------------
4: J Neurol. 2003 Jun;250(6):761-2. Related Articles, Links
Low-frequency transcranial magnetic stimulation
in patients with cortical dysplasia - a preliminary study.
Daniele O, Brighina F, Piazza A, Giglia G, Scalia S, Fierro B.
Publication Types:
* Letter
PMID: 12862035 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
5: Ann N Y Acad Sci. 2003 May;993:1-13; discussion 48-53. Related Articles, Links
Neuroprotection trek--the next generation: neuromodulation
I. Techniques--deep brain stimulation, vagus nerve stimulation, and transcranial
magnetic stimulation.
Andrews RJ.
NASA Ames Research Center, Moffett Field, California, USA. rja@russelljandrews.org
Neuromodulation denotes controlled electrical stimulation of the central or
peripheral nervous system. The three forms of neuromodulation described in this
paper-deep brain stimulation, vagus nerve stimulation, and transcranial magnetic
stimulation-were chosen primarily for their demonstrated or potential clinical
usefulness. Deep brain stimulation is a completely implanted technique for improving
movement disorders, such as Parkinson's disease, by very focal electrical stimulation
of the brain-a technique that employs well-established hardware (electrode and
pulse generator/battery). Vagus nerve stimulation is similar to deep brain stimulation
in being well-established (for the treatment of refractory epilepsy), completely
implanted, and having hardware that can be considered standard at the present
time. Vagus nerve stimulation differs from deep brain stimulation, however,
in that afferent stimulation of the vagus nerve results in diffuse effects on
many regions throughout the brain. Although use of deep brain stimulation for
applications beyond movement disorders will no doubt involve placing the stimulating
electrode(s) in regions other than the thalamus, subthalamus, or globus pallidus,
the use of vagus nerve stimulation for applications beyond epilepsy-for example,
depression and eating disorders-is unlikely to require altering the hardware
significantly (although stimulation protocols may differ). Transcranial magnetic
stimulation is an example of an external or non-implanted, intermittent (at
least given the current state of the hardware) stimulation technique, the clinical
value of which for neuromodulation and neuroprotection remains to be determined.
Publication Types:
* Review
* Review, Tutorial
PMID: 12853290 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
6: Clin Neurophysiol. 2003 May;114(5):777-98. Related Articles, Links
Transcranial magnetic stimulation and epilepsy.
Tassinari CA, Cincotta M, Zaccara G, Michelucci R.
Department of Neurosciences, Division of Neurology, Bellaria Hospital, Via Altura
3, 40139 Bologna, Italy. carloalberto.tassinari@ausl.bo.it
Epileptic conditions are characterized by an altered balance between excitatory
and inhibitory influences at the cortical level. Transcranial magnetic stimulation
(TMS) provides a noninvasive evaluation of separate excitatory and inhibitory
functions of the cerebral cortex. In addition, repetitive TMS (rTMS) can modulate
the excitability of cortical networks. We review the different ways that TMS
has been used to investigate pathophysiological mechanisms and effects of antiepileptic
drugs in patients with epilepsy and epileptic myoclonus. The safety of different
TMS techniques is discussed too. Finally, we discuss the therapeutic prospects
of rTMS in this field.
Publication Types:
* Review
* Review, Tutorial
PMID: 12738425 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
7: Arq Neuropsiquiatr. 2003 Mar;61(1):146-52. Epub 2003 Apr 16. Related Articles, Links
[Transcranial magnetic stimulation]
[Article in Portuguese]
Conforto AB, Marie SK, Cohen LG, Scaff M.
Divisao de Clinica Neurologica, Hospital das Clinicas, Faculdade de Medicina,
Universidade de Sao Paulo, Sao Paulo, SP, Brasil.
Transcranial magnetic stimulation (TMS) allows non-invasive study and modulation
of cortical excitability in humans. Changes in cortical excitability in physiological
and pathological conditions can be tracked by measurements such as motor threshold,
motor evoked potentials, recruitment curves, intracortical facilitation and
inhibition. The central motor conduction time can estimate neural transmission
in central motor pathways. Changes in areas of representation in sensorimotor
cortex can be studied with cortical mapping. Modulation of cortical processing
can be used to evaluate different brain functions. Therapeutic use in depression,
Parkinson's disease and epilepsy has raised great interest over the past decade.
Non-invasive cortical mapping may be achieved by combining TMS to other neurophysiological/
neuroimaging techniques. TMS has great potential both as an investigational
and as a therapeutical tool in Neurology and Psychiatry.
Publication Types:
* Review
* Review, Tutorial
PMID: 12715042 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
8: Zh Nevrol Psikhiatr Im S S Korsakova. 2003;103(1):61-6. Related Articles, Links
[Transcranial magnetic stimulation in the study
of epilepsy]
[Article in Russian]
Nikitina SS.
Publication Types:
* Review
* Review, Academic
PMID: 12616743 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
9: Epilepsy Behav. 2001 Aug;2(4):367-369. Related Articles, Links
Transcranial Magnetic Stimulation Evidence of
a Potential Role for Progesterone in the Modulation of Premenstrual Corticocortical
Inhibition in a Woman with Catamenial Seizure Exacerbation.
Herzog AG, Friedman MN, Freund S, Pascual-Leone A.
A transcranial magnetic stimulation paired-pulse paradigm was used to determine
that cortical excitability was less during the late luteal phase than in the
early follicular phase in a woman with epilepsy who had premenstrual seizure
exacerbation. The data are consistent with the possibility that a reduction
in GABA-mediated cortical inhibitory activity may be responsible. The administration
of progesterone, a reproductive steroid with potent GABAergic metabolites, during
the luteal phase restored cortical excitability to normal range.
PMID: 12609215 [PubMed - as supplied by publisher]
------------------------------------------------------------------------
10: Hum Brain Mapp. 2003 Mar;18(3):239-47. Related Articles, Links
Towards understanding language organisation
in the brain using fMRI.
Matthews PM, Adcock J, Chen Y, Fu S, Devlin JT, Rushworth MF, Smith S, Beckmann
C, Iversen S.
Centre for Functional Magnetic Resonance Imaging of the Brain, Department of
Clinical Neurology, John Radcliffe Hospital, Oxford, United Kingdom.
Functional magnetic resonance imaging (fMRI), which allows non-invasive mapping
of human cognitive functions, has become an important tool for understanding
language function. An understanding of component processes and sources of noise
in the images is contributing to increased confidence in the reproductability
of studies. This allows clinical applications, e.g., for pre-surgical lateralisation
of language functions in patients with temporal lobe epilepsy. fMRI is a sensitive
method for mapping regions involved in language functions. We recently have
applied it to study the effect of word surface form on reading with a comparison
of responses to Chinese characters or alphabetical Pinyin. Interpretation of
fMRI activations must be made with caution; fMRI suggests task-associated activation,
but does not independently confirm that such activity is necessary. However,
complementary studies can be performed using transcranial magnetic stimulation
(TMS), which can be used to interfere with brain activity in a specific region
transiently for characterisation of the behavioural effects. We describe how
TMS combined with fMRI has confirmed a role for the left inferior frontal cortex
in semantic processing. Copyright 2003 Wiley-Liss, Inc.
Publication Types:
* Review
* Review, Tutorial
PMID: 12599283 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
11: Neurology. 2002 Dec 24;59(12):1851-9. Related Articles, Links
Transcranial magnetic stimulation techniques
in clinical investigation.
Curra A, Modugno N, Inghilleri M, Manfredi M, Hallett M, Berardelli A.
Dipartimento di Scienze Neurologiche, Universita degli Studi di Roma La Sapienza,
Viale dell Universita 30, 00185 Rome, Italy.
Transcranial magnetic stimulation (TMS) is a technique that can activate cortical
motor areas and the corticospinal tract without causing the subject discomfort.
Since TMS was introduced, numerous applications of the technique have been developed
for the evaluation of neurologic diseases. Standard TMS applications (central
motor conduction time, threshold and amplitude of motor evoked potentials) allow
the evaluation of motor conduction in the CNS. Conduction studies provide specific
information in neurologic conditions characterized by clinical and subclinical
upper motor neuron involvement. In addition, they have proved useful in monitoring
motor abnormalities and the recovery of motor function. TMS also gives information
on the pathophysiology of the processes underlying the various clinical conditions.
More complex TMS applications (paired-pulse stimulation, silent period, ipsilateral
silent period, input-output curve, and evaluation of central fatigue) allow
investigation into the mechanisms of diseases causing changes in the excitability
of cortical motor areas. These techniques are also useful in monitoring the
effects of neurotrophic drugs on cortical activity. TMS applications have an
important place among the investigative tools to study patients with motor disorders.
Publication Types:
* Review
* Review, Tutorial
PMID: 12503582 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
12: Brain Cogn. 2002 Dec;50(3):366-86. Related Articles, Links
Transcranial magnetic stimulation: neurophysiological
applications and safety.
Anand S, Hotson J.
Department of Biological Sciences, San Jose State University, One Washington
Square, San Jose, CA 95192-0100, USA.
TMS is a non-invasive tool for measuring neural conduction and processing time,
activation thresholds, facilitation and inhibition in brain cortex, and neural
connections in humans. It is used to study motor, visual, somatosensory, and
cognitive functions. TMS does not appear to cause long-term adverse neurological,
cardiovascular, hormonal, motor, sensory, or cognitive effects in healthy subjects.
Single-pulse (<1Hz) TMS is safe in normal subjects. High frequency, high-intensity
repetitive TMS (rTMS) can elicit seizures even in normal subjects. Safety guidelines
for using rTMS have been published.
Publication Types:
* Review
* Review, Academic
PMID: 12480484 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
13: J Clin Neurophysiol. 2002 Aug;19(4):294-306. Related Articles, Links
Transcranial magnetic stimulation and epilepsy.
Macdonell RA, Curatolo JM, Berkovic SF.
Department of Neurology, Austin & Repatriation Medical Centre, Heidelberg,
Victoria, Australia.
Transcranial magnetic stimulation has been used to study generalized and focal
epilepsies for more than a decade. The technique appears safe and has yielded
important information about the mechanisms underlying epilepsy. Transcranial
magnetic stimulation findings differ depending on the epilepsy syndrome, lending
support to the concept that there are distinct pathophysiologies underlying
each condition. In most studies of generalized epilepsies, transcranial magnetic
stimulation has indicated a state of relative hyperexcitability of excitatory
cortical interneurons and possibly inhibitory interneurons as well, which can
be reversed through the actions of anticonvulsant medications. Transcranial
magnetic stimulation studies in patients with a seizure focus in the motor cortex
indicate increased cortical excitability and reduced inhibition, but in patients
with seizure foci located elsewhere the findings are similar to those in generalized
epilepsies. Transcranial magnetic stimulation has also been used to study the
mode of action of anticonvulsants and may prove to be a useful means of testing
the potential for new drugs to act as anticonvulsants. Repetitive transcranial
magnetic stimulation may prove to have a therapeutic role by producing long-lasting
cortical inhibition after a train of impulses.
Publication Types:
* Review
* Review, Tutorial
PMID: 12436086 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
14: Neurology. 2002 Oct 8;59(7):1028-33. Related Articles, Links
Comment in:
* Neurology. 2003 Feb 11;60(3):527-8; author reply 527-8.
Reduced inhibition within primary motor cortex
in patients with poststroke focal motor seizures.
Kessler KR, Schnitzler A, Classen J, Benecke R.
Department of Neurology, University of Frankfurt, Frankfurt/Main, Germany. k.kessler@em.uni-frankfurt.de
BACKGROUND: Following an ischemic brain lesion, the affected cortex undergoes
structural and functional changes that may lead to increased cortical excitability
or decreased inhibitory neuronal activity, resulting in the occurrence of poststroke
epileptic seizures in 6 to 10% of patients with stroke. METHODS: To assess motor
cortical excitability, transcranial magnetic stimulation (TMS) was used to determine
the silent period (SP) duration in 84 consecutive patients with ischemic stroke.
RESULTS: In a subpopulation of six patients (38 to 72 years old) a significant
decrease of the SP duration (mean 116 +/- 14 msec) was detected in either the
arm or the leg on the affected side as compared to the corresponding unaffected
limb (mean 231 +/- 32 msec). This electrophysiologic abnormality was clinically
associated with focal motor seizures in five of the six patients, whereas none
of the other 76 patients with normal or prolonged SP durations developed seizures
or epilepsy. CONCLUSIONS: Silent period shortening in this group reflects decreased
inhibitory activity that may partly be related to functional or structural impairment
of GABAergic interneurons. TMS may be of value for determining patients with
stroke at risk for developing poststroke seizures.
PMID: 12370457 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
15: Epilepsia. 2002 Oct;43(10):1149-56.
Topiramate selectively decreases intracortical
excitability in human motor cortex.
Reis J, Tergau F, Hamer HM, Muller HH, Knake S, Fritsch B, Oertel WH, Rosenow
F.
Interdisciplinary Epilepsy Center, Department of Neurology, Philipps-University,
Marburg, Germany.
PURPOSE: Topiramate (TPM) is a novel drug with broad antiepileptic effect in
children and adults. In vitro studies suggest activity as sodium-channel blocker,
as gamma-aminobutyric acid type A (GABAA)-receptor agonist and as non-N-methyl-D-aspartate
(NMDA)-glutamate receptor antagonist. METHODS: With transcranial magnetic stimulation
(TMS), we evaluated which of the mechanisms of action of TPM detected in vitro
are relevant for the modulation of human motor cortex excitability. In a double-blind,
placebo-controlled, crossover study design, we investigated the effect of single
oral doses of 50 mg and 200 mg TPM on motor thresholds, cortical silent period
(CSP), and on intracortical inhibition (ICI) and intracortical facilitation
(ICF) in 20 healthy subjects. RESULTS: A significant dose-dependent increase
of ICI was noticed after 200 mg TPM as compared with placebo at short interstimulus
intervals of 2 to 4 ms. TPM had no effect on motor thresholds or the CSP. CONCLUSIONS:
We conclude that a single dose of TPM selectively increases ICI by GABAAergic
and/or glutamatergic mechanisms without a relevant influence on measures, depending
on ion-channel blockade or GABAB-receptor activity. The decrease of intracortical
excitability (as measured by ICI and ICF) caused by TPM may correlate with its
lack of proconvulsive potential in idiopathic generalized epilepsy, because
drugs without this action or with less pronounced action may exacerbate seizures
in this condition.
PMID: 12366728 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
16: Neurology. 2002 Sep 24;59(6 Suppl 4):S56-61. Related Articles, Links
Vagus nerve stimulation therapy: a research
update.
George MS, Nahas Z, Bohning DE, Kozel FA, Anderson B, Chae JH, Lomarev M, Denslow
S, Li X, Mu C.
502 North, IOP, Department of Psychiatry, Medical University of South Carolina,
67 President Street, Charleston, SC 29425, USA.
Over the past 5 years, and especially within the last year, there has been a
rapid expansion of vagus nerve stimulation (VNS)-related preclinical research,
as well as clinical studies in indications other than epilepsy. The research
advances in understanding VNS are occurring in the midst of a blossoming of
other forms of therapeutic brain stimulation, such as electroconvulsive therapy
(ECT), transcranial magnetic stimulation (TMS), and deep brain stimulation (DBS).
In general, improved understanding of the neurobiological effects of VNS therapy
as a function of the different use parameters (frequency, intensity, pulse width,
duration, dose) is beginning to guide clinical use and help determine which
diseases, in addition to epilepsy, VNS might treat.
Publication Types:
* Review
* Review Literature
PMID: 12270970 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
17: Rinsho Shinkeigaku. 2001 Dec;41(12):1097-9. Related Articles, Links
[Treatment of status epilepticus]
[Article in Japanese]
Tsuji S, Akamatsu N.
Status epilepticus (SE) is a condition requiring emergency care. There are convulsive
SE, non-convulsive SE including complex partial status and absence status, non-convulsive
electric SE and pseudostatus epilepticus, although convulsive SE is the most
common. Diagnosis of status epilepticus of complex partial seizures (CPS) and
absence seizures was significantly delayed because delays in seeking medical
attention were common. The seizures were generalized convulsive SE in 84% and
CPS status in 16%, and the overall mortality rate was 15% in 41 SE patients
of our study. EEG monitoring is important to make or exclude the diagnosis of
SE. Diazepam is the first choice medication and effective in the management
of SE, and lately, lorazepam, midazolam, propofol and pentobarbital etc as emergency
therapy. Phenytoin is also considered first-line agent in the emergency management
of SE. Repetitive transcranial magnetic stimulation (rTMS) led to a prolonged
latency for seizure induction after an intraperitoneal injection of pentylenetetrazol
(PTZ) and effectively prevented the development of status epilepticus of PTZ-induced
convulsions in the rats. Our data suggest that rTMS has suppressive effects
on the neuronal excitability in rats. These effects are anticonvulsive and suggest
the possibility of therapeutic use of rTMS in the patients with refractory seizures.
Publication Types:
* Review
* Review, Tutorial
PMID: 12235807 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
18: Neurology. 2002 Aug 27;59(4):560-2. Related Articles, Links
Transcranial magnetic stimulation for the treatment
of seizures: a controlled study.
Theodore WH, Hunter K, Chen R, Vega-Bermudez F, Boroojerdi B, Reeves-Tyer P,
Werhahn K, Kelley KR, Cohen L.
Clinical Epilepsy, National Institute of Neurological Disorders and Stroke,
National Institutes of Health, Bethesda, MD 20892, USA.
OBJECTIVE: To perform a controlled trial of transcranial magnetic stimulation
(TMS). METHODS: Twenty-four patients with localization-related epilepsy were
randomized to blinded active or placebo stimulation. Weekly seizure frequency
was compared for 8 weeks before and after 1 week of 1-Hz TMS for 15 minutes
twice daily. RESULTS: When the 8-week baseline and post-stimulation periods
were compared, active patients had a mean seizure frequency reduction of 0.045
+/- 0.13 and sham-stimulated control subjects -0.004 +/- 0.20. Over 2 weeks,
actively treated patients had a mean reduction in weekly seizure frequency of
0.16 +/- 0.18 and sham-stimulated control subjects 0.01 +/- 0.24. Neither difference
was significant. CONCLUSION: The effect of TMS on seizure frequency was mild
and short lived.
Publication Types:
* Clinical Trial
* Randomized Controlled Trial
PMID: 12196649 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
19: J Psychosom Res. 2002 Aug;53(2):709-19. Related Articles, Links
Novel physical treatments for the management
of neuropsychiatric disorders.
Malhi GS, Sachdev P.
School of Psychiatry, University of New South Wales, Sydney, Australia.
OBJECTIVE: To briefly describe the novel non-drug physical interventions currently
in use in the investigation and treatment of neuropsychiatric disorders regarding
their efficacy and potential future applications. METHODS: A systematic review
of the literature concerning transcranial magnetic stimulation (TMS), deep brain
stimulation (DBS), vagus nerve stimulation (VNS) and neurosurgery for mental
disorders (NMD) was conducted using Medline and literature known to the authors.
RESULTS: A summary of each procedure is provided giving a succinct overview
of efficacy, current applications and possible future indications. CONCLUSION:
Novel and innovative physical interventions are currently being used to study
brain function in health and disease. In particular, TMS has quickly established
itself as a useful investigational tool and is emerging as a possible antidepressant
therapy. Similarly, VNS has been applied successfully in the management of intractable
epilepsy and is undergoing evaluation in the management of patients with treatment-resistant
depression. DBS has shown significant promise in the treatment of Parkinson's
disease and may have use in the management of obsessive-compulsive disorder.
Finally, neurosurgical procedures for the treatment of mental disorders have
been sufficiently refined to stage a comeback, although rigorous scientific
study of their efficacy and indications is still necessary.
Publication Types:
* Review
* Review, Tutorial
PMID: 12169345 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
20: Ann Neurol. 2002 Jul;52(1):119-22. Related Articles, Links
In vivo study indicating loss of intracortical
inhibition in tumor-associated epilepsy.
Irlbacher K, Brandt SA, Meyer BU.
Department of Neurology, Charite, Humboldt-University, Berlin, Germany.
Transcranial magnetic stimulation was performed in 2 patients with focal motor
seizures in the right hand caused by a circumscribed tumor process affecting
the left precentral gyrus. In both cases, paired-pulse transcranial magnetic
stimulation showed a loss of intracortical inhibition for interstimulus intervals
of 2 to 4msec that was replaced by an enormous facilitation in the lesioned
hand motor cortex. The uniform impairment of inhibitory mechanisms in epileptogenic
tumors with different histologies suggests a common, nonspecific cause of tumor-related
epileptogenesis.
PMID: 12112060 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
21: Am J Psychiatry. 2002 Jul;159(7):1093-102. Related Articles, Links
Slow transcranial magnetic stimulation, long-term
depotentiation, and brain hyperexcitability disorders.
Hoffman RE, Cavus I.
Yale-New Haven Psychiatric Hospital, Yale University School of Medicine, LV
108, 20 York Street, New Haven, CT 06504, USA.
OBJECTIVE: Many clinical syndromes in neuropsychiatry suggest focal brain activation.
Repetitive transcranial magnetic stimulation (rTMS) has been proposed as a method
for selectively altering neural activity. METHOD: Studies assessing effects
of "slow" rTMS, administered up to once per second, in normal people and in
those with pathological conditions are reviewed. The findings are compared with
those of animal studies examining long-term depression and long-term depotentiation
through direct electrical stimulation of cortical tissue. RESULTS: Data suggest
that slow rTMS reduces cortical excitability, both locally and in functionally
linked cortical regions. Preliminary studies of patients with focal dystonia,
epileptic seizures, and auditory hallucinations indicate symptom reductions
following slow rTMS. Long-term depotentiation exhibits many features congruent
with those of slow rTMS, including frequency dependence, spread to functionally
linked cortical regions, additive efficacy, and extended duration of effects.
CONCLUSIONS: Slow rTMS offers a new method for probing and possibly treating
brain hyperexcitability syndromes. Further studies linking slow rTMS to animal
models of neuroplasticity are indicated.
Publication Types:
* Review
* Review, Tutorial
PMID: 12091184 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
22: J Child Neurol. 2002 Apr;17(4):292-7. Related Articles, Links
Interhemispheric reorganization of motor hand
function to the primary motor cortex predicted with functional magnetic resonance
imaging and transcranial magnetic stimulation.
Rutten GJ, Ramsey NF, van Rijen PC, Franssen H, van Veelen CW.
Department of Neurosurgery, University Medical Center Utrecht, The Netherlands.
g.rutten@neuro.azu.nl
The objective of this study was presurgical assessment of reorganization of
motor hand function in an 11-year-old girl with intractable epilepsy and a right-sided
hemiplegia resulting from an extensive perinatal left hemispheric stroke. Prior
to a left functional hemispherectomy, functional magnetic resonance imaging
(MRI) showed that both nonparetic and paretic motor hand function predominantly
activated the right primary motor cortex, whereas no activation was found in
the left hemisphere. Transcranial magnetic stimulation of the right central
area yielded responses in both the nonparetic and the paretic hand, whereas
no responses were obtained after stimulation of the affected hemisphere. Both
techniques indicated that motor function was mediated by corticospinal fibers
originating from the undamaged (primary) motor cortex and predicted no further
loss of motor hand function after surgery. Indeed, subsequent functional hemispherectomy
induced no new sensorimotor deficits. Functional MRI was repeated 22 months
after surgery and matched preoperative sensorimotor functional MRI findings,
confirming reorganization of the primary motor cortex. No additional reorganization
was introduced by surgery.
PMID: 12088086 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
23: Curr Neurol Neurosci Rep. 2002 Jul;2(4):357-64. Related Articles, Links
Neurostimulation therapy for epilepsy.
Labar D, Dean A.
Comprehensive Epilepsy Center, New York Presbyterian Hospital-Weill Cornell
Medical Center, 525 East 68th Street, K-615, New York, NY 10021, USA.
Neurostimulation therapy for epilepsy is growing in popularity. By appropriate
targeting of applied electrical activation at selected nervous system sites,
antiseizure effects may be achieved without the common sedative side effects
of antiepileptic medications. Risks of neurostimulation therapy are those associated
with the device implantation surgical procedures. Vagus nerve stimulation (VNS)
reduces seizures by 45% and has been employed in over 13,000 patients worldwide.
New reports suggest VNS is particularly beneficial for patients with Lennox-Gastuat
syndome. VNS also reduces sudden unexpected death in epilepsy. New publications
describing small, uncontrolled case series also suggest deep brain stimulation
and transcranial magnetic stimulation may develop into effective antiepileptic
therapies in the future.
Publication Types:
* Review
* Review, Tutorial
PMID: 12044255 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
24: Nervenarzt. 2002 Apr;73(4):332-5. Related Articles, Links
[Modulation of cortical excitability by transcranial
direct current stimulation]
[Article in German]
Nitsche MA, Liebetanz D, Tergau F, Paulus W.
Abteilung Klinische Neurophysiolgie, Georg-August-Universitat Gottingen.
Modulation of cerebral excitability is thought to be one mechanism underlying
the pharmacological treatment of neuropsychiatric diseases such as epilepsy,
depression, and dystonia. Repetitive transcranial magnetic stimulation (rTMS)
has been tested for several years as a nonpharmacological, noninvasive method
of directly influencing patients' cortical functions. We present an overview
of the more easily performed transcranial direct current stimulation (tDCS)
with weak current, which produces distinctly more pronounced changes in excitability
than rTMS. The basic underlying mechanism is a shift in the resting membrane
potential towards either hyper- or depolarisation, depending on stimulation
polarity. This in turn leads to changes in the excitability of cortical neurons.
Anodic stimulation increases cortical excitability, while cathodic stimulation
decreases it. These changes persist after the end of stimulation if the stimulation
lasts long enough, i.e., at least several minutes. The duration of this aftereffect
can be controlled through the duration and intensity of the stimulation. Transcranial
direct current stimulation essentially allows a focal, selective, reversible,
pain-free, and noninvasive induction of changes in cortical excitability, the
therapeutic potential of which must be evaluated in clinical studies, once possible
risk factors have been assessed.
Publication Types:
* Review
* Review, Tutorial
PMID: 12040980 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
25: Clin Neurophysiol. 2002 Apr;113(4):597-603. Related Articles, Links
Cortical silent period in two patients with
meningioma and preoperative seizures: a pre- and postsurgical follow-up study.
Cincotta M, Borgheresi A, Benvenuti F, Liotta P, Marin E, Zaccara G.
Unita Operativa di Neurologia, Azienda Sanitaria di Firenze, Ospedale S. Maria
Nuova, Piazza S. Maria Nuova 1, 50122, Florence, Italy.
OBJECTIVES: Prolongation of the cortical silent period (CSP) following transcranial
magnetic stimulation has been reported in patients with partial epilepsy involving
the primary motor cortex (M1). This study aimed to investigate the relationship
between the expected intraindividual variations in risk factors for seizures
and CSP duration. METHODS: We studied a 59-year-old woman with a rolandic meningioma
and simple motor partial seizures and a 71-year-old woman with a parietal/occipital
meningioma and complex partial seizures. Both patients had seizure as their
initial symptom with complete postsurgical remission. Repeated pre- and postoperative
CSP recordings were made from both first dorsal interosseous muscles. We compared
the results to those obtained in 13 normals. RESULTS: In the patient with simple
motor partial seizures, the CSP was significantly prolonged in preoperative
recordings and 3 weeks after surgery. This CSP lengthening partly subsided 3
months after surgery. Finally, the CSP was normal 6, 8, and 18 months after
surgery. In the patient with complex partial seizures, no CSP change was observed.
CONCLUSIONS: In our patient with a rolandic meningioma, CSP prolongation was
observed when the risk of seizure relapse was supposed to be higher (preoperative
and early postoperative periods). This supports the view that CSP changes reflect
compensatory mechanisms in M1 epilepsy.
PMID: 11956005 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
26: Acta Psychiatr Scand. 2002 May;105(5):324-40. Related Articles, Links
The application of transcranial magnetic stimulation
in psychiatry and neurosciences research.
Fitzgerald PB, Brown TL, Daskalakis ZJ.
Dandenong Psychiatry Research Centre, Department of Psychological Medicine,
Monash University, PO Box 956, Dandenong, Victoria 3175, Australia.
OBJECTIVE: Over recent years transcranial magnetic stimulation (TMS) has become
widely applied in the study of neuropsychiatric disorders. The aim of this article
is to review the application of TMS as an investigative tool and as a potential
therapeutic modality in psychiatric disorders. METHOD: A comprehensive literature
review. RESULTS: When applied as an investigative tool, TMS provides innovative
ways to directly study the excitability of the cortex, cortical regional connectivity,
the plasticity of brain responses and cognitive functioning in illness and disease
states. A number of studies suggest the potential of treatment with TMS in disease
states, especially in patients with depression, although difficulties exist
with the interpretation of the published literature. CONCLUSION: TMS has a considerable
role in neuropsychiatric research. It appears to have considerable potential
as a therapeutic tool in depression, and perhaps a role in several other disorders,
although widespread application requires larger trials and establishment of
sustained response.
Publication Types:
* Review
* Review, Tutorial
PMID: 11942939 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
27: Neurology. 2002 Apr 9;58(7):1135; author reply 1135. Related Articles, Links
Comment on:
* Neurology. 1992 Oct;42(10):1951-9.
* Neurology. 2001 Aug 28;57(4):706-8.
Prolonged cortical silent period after transcranial
magnetic stimulation in generalized epilepsy.
Cantello R.
Publication Types:
* Comment
* Letter
PMID: 11940718 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
28: Neurology. 2001 Nov 27;57(10):1793-9. Related Articles, Links
Hyperexcitable cortical responses in progressive
myoclonic epilepsy: a TMS study.
Manganotti P, Tamburin S, Zanette G, Fiaschi A.
Department of Neurological Sciences and Vision, Section of Neurological Rehabilitation,
University of Verona, Italy.
OBJECTIVE: Transcranial magnetic stimulation (TMS) has allowed investigators
to study intracortical inhibition and facilitation and sensorimotor integration
in motor disorders and epilepsy. The authors used TMS to elucidate the pathophysiology
of reflex myoclonus with giant somatosensory evoked potentials (SEP). METHODS:
The authors studied four patients with progressive myoclonic epilepsy. All patients
had giant SEP elicited by mixed and digital nerve stimulation. They studied
the response to paired-pulse TMS at interstimulus intervals (ISI) ranging from
1 to 15 ms and the conditioning effect of digital electrical stimulation at
ISI ranging from 10 to 100 ms on the motor evoked potential amplitude to TMS.
RESULTS: Digital stimulation markedly facilitated conditioned motor evoked potentials
at ISI ranging from 25 to 40 ms in all patients. This pattern was significantly
different from the inhibition observed in controls (n = 12) at the same ISI.
In the patients, paired-pulse TMS showed a decrease in intracortical inhibition
in the motor cortex in comparison with controls. CONCLUSIONS: These findings
suggest cortical and subcortical components of abnormal sensorimotor integration
in addition to hyperexcitability of the sensory and motor cortex in our myoclonic
patients.
PMID: 11723265 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
29: J Neurol Neurosurg Psychiatry. 2001 Dec;71(6):809-12. Related Articles, Links
Cortical excitability and sleep deprivation:
a transcranial magnetic stimulation study.
Civardi C, Boccagni C, Vicentini R, Bolamperti L, Tarletti R, Varrasi C, Monaco
F, Cantello R.
Clinica Neurologica, Ospedale Maggiore, Corso Mazzini 18, 28100 Novara, Italy.
The objective was to assess the changes in cortical excitability after sleep
deprivation in normal subjects. Sleep deprivation activates EEG epileptiform
activity in an unknown way. Transcranial magnetic stimulation (TMS) can inform
on the excitability of the primary motor cortex. Eight healthy subjects (four
men and four women) were studied. Transcranial magnetic stimulation (single
and paired) was performed by a focal coil over the primary motor cortex, at
the "hot spot" for the right first dorsal interosseous muscle. The following
motor evoked potential features were measured: (a) active and resting threshold
to stimulation; (b) duration of the silent period; (c) amount of intracortical
inhibition on paired TMS at the interstimulus intervals of 2 and 3 ms and amount
of facilitation at interstimulus intervals of 14 and 16 ms. The whole TMS session
was repeated after a sleep deprivation of at least 24 hours. After the sleep
deprivation, the threshold to stimulation (in the active and resting muscle),
as well as the silent period, did not change significantly. By contrast, the
paired stimulus study showed a significant (p<0.05) reduction in both intracortical
inhibition and facilitation. Thus, TMS showed that sleep deprivation is associated
with changes in inhibition-facilitation balance in the primary motor cortex
of normal subjects. These changes might have a link with the background factors
of the "activating" effects of sleep deprivation.
Publication Types:
* Validation Studies
PMID: 11723210 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
30: J Neurol Neurosurg Psychiatry. 2001 Dec;71(6):772-6. Related Articles, Links
Reduced excitability of the motor cortex in
untreated patients with de novo idiopathic "grand mal" seizures.
Delvaux V, Alagona G, Gerard P, De Pasqua V, Delwaide PJ, Maertens de Noordhout
A.
University Department of Neurology, Hopital de la Citadelle, B-4000 Liege, Belgium.
OBJECTIVES: Transcranial magnetic stimulation (TMS) was used to investigate
motor cortex excitability, intracortical excitatory, and inhibitory pathways
in 18 patients having experienced a first "grand mal" seizure within 48 hours
of the electrophysiological test. All had normal brain MRI, and were free of
any treatment, drug, or alcohol misuse. Results were compared with those of
35 age matched normal volunteers. METHODS: The following parameters of responses
to TMS were measured: motor thresholds at rest and with voluntary contraction,
amplitudes of responses, cortical silent periods, and responses to paired pulse
stimulation with interstimulus intervals of 1 to 20 ms. RESULTS: In patients,
there were significantly increased motor thresholds with normal amplitudes of
motor evoked potentials (MEPs), suggesting decreased cortical excitability.
Cortical silent periods were not significantly different from those of normal
subjects. Paired TMS with short interstimulus intervals (1-5 ms) induced normal
inhibition of test MEPs, suggesting preserved function of GABAergic intracortical
inhibitory interneurons. On the contrary, the subsequent period of MEP facilitation
found in normal subjects (ISIs of 6-20 ms) was markedly reduced in patients.
This suggests the existence of abnormally prolonged intracortical inhibition
or deficient intracortical excitation. In nine patients retested 2 to 4 weeks
after the initial seizure, these abnormalities persisted, although to a lesser
extent. CONCLUSION: The present findings together with abnormally high motor
thresholds could represent protective mechanisms against the spread or recurrence
of seizures.
PMID: 11723199 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
31: Brain. 2001 Dec;124(Pt 12):2459-75. Related Articles, Links
Autosomal dominant cortical myoclonus and epilepsy
(ADCME) with complex partial and generalized seizures: A newly recognized epilepsy
syndrome with linkage to chromosome 2p11.1-q12.2.
Guerrini R, Bonanni P, Patrignani A, Brown P, Parmeggiani L, Grosse P, Brovedani
P, Moro F, Aridon P, Carrozzo R, Casari G.
Neurosciences Unit, Institute of Child Health and Great Ormond Street Hospital
for Children, London, UK.
We describe a pedigree in which eight individuals presented with a non-progressive
disorder with onset between the ages of 12 and 50 years. It was characterized
by predominantly distal, semi-continuous rhythmic myoclonus (all patients),
generalized tonic-clonic seizures (all patients) and complex partial seizures
(three patients). Most individuals had rarely suffered seizures and had a normal
cognitive level, but three individuals with intractable seizures had mild mental
retardation. The pattern of inheritance was autosomal dominant with high penetrance.
We defined this disorder as autosomal dominant cortical myoclonus and epilepsy
(ADCME). All patients had frontotemporal as well as generalized interictal EEG
abnormalities. A neurophysiological study of the myoclonus suggested a cortical
origin. Back-averaging of the data generated a series of waves with a frequency
that mirrored the frequency of EMG bursts. Frequency analysis identified significant
peaks with coherence between EMG and EEG, which were recorded over the contralateral
rolandic area in five patients. The frequency of coherence was 8-25 Hz and phase
spectra confirmed that EEG activity preceded EMG activity by 8-15 ms. In two
individuals there was also significant coherence between the ipsilateral EEG
and EMG, consistent with the transcallosal spread of myoclonic activity. The
C-reflex at rest was enhanced and somatosensory and visual evoked potentials
were of high amplitude. The resting motor threshold intensity to transcranial
magnetic stimulation was significantly reduced (38%; SD +/- 7; P = 0.01) and
the post-motor evoked potential silent period (101 ms; SEM +/- 10) was significantly
shortened compared with the controls (137 ms; SEM +/- 18). These clinical and
neuro- physiological characteristics suggest diffuse cortical hyperexcitability
and high propensity for intra-hemispheric and inter-hemispheric cortical spread,
as well as rhythmic myoclonic activity. Genome-wide linkage analysis identified
a critical region spanning 12.4 cM between markers D2S2161 and D2S1897 in 2p11.1-q12.2,
with a maximum two-point LOD score of 3.46 at Theta 0.0 for marker D2S2175.
Multipoint LOD score values, reaching 3.74 around D2S2175, localize the ADCME
gene to the centromeric region of chromosome 2. The exclusion of the locus for
familial adult myoclonic epilepsy on chromosome 8q23.3-q24 from linkage to our
family and the new localization of the responsible gene to chromosome 2cen,
together with the different phenotype, define a new epilepsy syndrome. We hypothesize
that the responsible gene causes cortical hyperexcitability that is widespread
but particularly involves the frontotemporal circuits.
PMID: 11701600 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
32: Can J Psychiatry. 2001 Oct;46(8):720-7. Related Articles, Links
Transcranial magnetic stimulation in the treatment
of mood disorder: a review and comparison with electroconvulsive therapy.
Hasey G.
Regional Mood Disorders Program, Department of Psychiatry, McMaster University,
Hamilton, Ontario, Canada.
OBJECTIVE: To review repetitive transcranial magnetic stimulation (rTMS) as
a mode of therapy for depression. METHOD: The following aspects of rTMS were
reviewed and compared with electroconvulsive therapy (ECT): history, basic principles,
technical considerations, possible mode of action, safety, adverse effects,
and effects on mood in both healthy individuals and those suffering from bipolar
disorder (BD) or depression. RESULTS: rTMS may selectively increase or decrease
neuronal activity over discrete brain regions. As a result of this focused intervention
with TMS, the potential for unwanted side effects is substantially reduced,
compared with ECT. In open trials, rTMS and ECT are reported to be equally efficacious
for patients having depression without psychosis, but the therapeutic benefits
reported in double-blind sham-rTMS controlled trials are more modest. CONCLUSION:
The antidepressant and antimanic effects of rTMS depend on technical considerations
such as stimulus frequency, intensity, and magnetic coil placement, which may
not yet be optimized. Biological heterogeneity among the patients treated with
rTMS may also contribute to differing efficacy across clinical trials. rTMS
may possess tremendous potential as a treatment for mood disorder, but this
has not yet been realized. rTMS must still be regarded as an experimental intervention
requiring further refinement.
Publication Types:
* Review
* Review, Tutorial
PMID: 11692974 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
33: Neurosci Lett. 2001 Sep 14;310(2-3):153-6. Related Articles, Links
Decreased susceptibility to pentylenetetrazol-induced
seizures after low-frequency transcranial magnetic stimulation in rats.
Akamatsu N, Fueta Y, Endo Y, Matsunaga K, Uozumi T, Tsuji S.
Department of Neurology, University of Occupational and Environmental Health,
School of Medicine, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan.
We studied the effects of low-frequency repetitive transcranial magnetic stimulation
(rTMS) on seizure susceptibility in rats. rTMS of 1000 pulses at 0.5 Hz led
to a prolonged latency for seizure development after an intraperitoneal injection
of pentylenetetrazol. The rTMS effectively prevented the development of status
epilepticus of pentylenetetrazol-induced convulsions. These findings indicate
that low-frequency rTMS affects the neural excitability, in the direction of
anticonvulsive, and therefore, suggest the possibility of therapeutic use of
rTMS in epilepsy.
PMID: 11585590 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
34: Expert Opin Pharmacother. 2001 Jul;2(7):1061-3. Related Articles, Links
Vagus nerve stimulation in depression.
Goodnick PJ, Rush AJ, George MS, Marangell LB, Sackeim HA.
University of Miami School of Medicine, FL 33136, USA.
Ever since the introduction of chemical and electrical convulsive treatment
for psychiatric disorders in the 1930s and 1940s, biological techniques have
been used extensively in the amelioration of a variety of psychiatric disorders.
Techniques of recent vintage have included transcranial magnetic stimulation,
deep brain stimulation and vagus nerve stimulation (VNS). Since VNS attenuates
seizures in animal models, the treatment was initially developed and approved
by the FDA for treatment of drug-resistant partial-onset epilepsy. Additional
data, including the known neuroanatomy of the vagus nerve, effects of VNS on
monoamines and mood improvement in patients with epilepsy who were treated with
VNS, provided a rationale for further investigation in patients with primary
mood disorders. VNS has been administered acutely for 10 weeks to 60 patients
with treatment-resistant depression. Longer-term follow-up data has been analysed
for the first 30 patients. Response rates have been at least 30% in the acute
study. Similar to findings in epilepsy and in contrast to the usual results
of long-term medication trials, longer term data regarding symptomatic and functional
outcomes of depressed patients receiving VNS continue to look promising. As
opposed to electroconvulsive therapy, VNS is not associated with cognitive impairment.
These results have led to approval of VNS for the treatment of resistant depression
(unipolar or bipolar) in both Europe and Canada. Currently, a pivotal double-blind
acute study is underway in the US.
Publication Types:
* Review
* Review, Tutorial
PMID: 11583056 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
35: J ECT. 2001 Sep;17(3):195-7. Related Articles, Links
Magnetic and seizure thresholds before and after
six electroconvulsive treatments.
Amiaz R, Stein O, Schreiber S, Danon PN, Dolberg OT, Grunhaus L.
Psychiatry Department C, The Chaim Sheba Medical Center, Tel-Hashomer, Israel.
OBJECTIVES: Electroconvulsive therapy (ECT) is a well-established treatment
in psychiatry. It has been reported that in patients with nondelusional major
depression, transcranial magnetic stimulation (TMS) may substitute for ECT.
To explore whether ECT and TMS share mechanisms of action, we studied the effects
of ECT on both seizure threshold (ST) and magnetic motor threshold (MT). METHODS:
We measured ST and MT in 10 patients referred for ECT. MT was defined as the
minimal power of the TMS equipment at which a motor evoked potential (MEP) response
could be detected 50% of the time. ST was defined as the minimal intensity of
electrical stimulation needed to elicit an adequate seizure. ECT was performed
following the methods recommended by the American Psychiatric Association. All
subjects signed an informed consent for participation in the research. RESULTS:
We measured MT and ST in 10 patients before and after 6 ECT treatments. No changes
in MT were detected from the treatment (paired t-test: t = 1.05, SD = 4.78,
p = 0.25). ST, on the other hand, increased significantly with treatment (paired
t-test: t = 2.99, SD = 190.20, p < 0.001). CONCLUSIONS: ECT and TMS do not
share a common mechanism at least with regard to MT and ST.
Publication Types:
* Clinical Trial
PMID: 11528311 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
36: Neurology. 2001 Aug 28;57(4):706-8. Related Articles, Links
Comment in:
* Neurology. 2002 Apr 9;58(7):1135; discussion 1135.
Prolonged cortical silent period after transcranial
magnetic stimulation in generalized epilepsy.
Macdonell RA, King MA, Newton MR, Curatolo JM, Reutens DC, Berkovic SF.
Department of Neurology, Austin and Repatriation Medical Centre, Heidelberg,
Victoria, Australia.
Transcranial magnetic stimulation (TMS) produces a cortical silent period (CSP)
during a voluntary contraction. The duration of the CSP was used to assess the
level of intracortical inhibition in patients with untreated idiopathic generalized
epilepsy (IGE). Mean CSP duration was assessed at three TMS stimuli in 21 patients
with IGE compared with 19 normal control subjects. Mean CSP duration was increased
at all stimulus intensities, indicating that intracortical inhibition is increased
in patients with IGE.
PMID: 11524485 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
37: Ann N Y Acad Sci. 2001 Jun;930:179-92. Related Articles, Links
Cerebral substrates of musical imagery.
Halpern AR.
Psychology Department, Bucknell University, Lewisburg, PA 17837, USA. ahalpern@bucknell.edu
Musical imagery refers to the experience of "replaying" music by imagining it
inside the head. Whereas visual imagery has been extensively studied, few people
have investigated imagery in the auditory domain. This article reviews a program
of research that has tried to characterize auditory imagery for music using
both behavioral and cognitive neuroscientific tools. I begin by describing some
of my behavioral studies of the mental analogues of musical tempo, pitch, and
temporal extent. I then describe four studies using three techniques that examine
the correspondence of brain involvement in actually perceiving vs. imagining
familiar music. These involve one lesion study with epilepsy surgery patients,
two positron emission tomography (PET) studies, and one study using transcranial
magnetic stimulation (TMS). The studies converge on the importance of the right
temporal neocortex and other right-hemisphere structures in the processing of
both perceived and imagined nonverbal music. Perceiving and imagining songs
that have words also involve structures in the left hemisphere. The supplementary
motor area (SMA) is activated during musical imagery; it may mediate rehearsal
that involves motor programs, such as imagined humming. Future studies are suggested
that would involve imagery of sounds that cannot be produced by the vocal tract
to clarify the role of the SMA in auditory imagery.
Publication Types:
* Review
* Review, Tutorial
PMID: 11458829 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
38: Brain. 2001 Jul;124(Pt 7):1336-49. Related Articles, Links
Effect of multiple subpial transection on motor
cortical excitability in cortical dysgenesis.
Shimizu T, Maehara T, Hino T, Komori T, Shimizu H, Yagishita A, Yokota T, Hirai
S, Rossini PM.
Departments of Neurology, Neurosurgery, and Neuroradiology, Tokyo Metropolitan
Neurological Hospital, Japan.
We report here a 12-year-old patient with unilateral cortical dysgenesis and
intractable simple partial seizure in his left arm, who underwent multiple subpial
transection (MST) in the right cerebral cortex including the primary motor cortex.
We investigated motor cortical excitability using multimodal transcranial magnetic
stimulation (TMS) before and 1 month after MST, in which surgical cortical incisions
were made with strokes 5 mm apart and 4 mm deep. Preoperative TMS studies showed
hyperexcitability in the affected motor cortex as abnormally prolonged muscle
responses to TMS with a wide cortical motor map, which were markedly reduced
following the operation. The preoperative motor evoked potentials were large
and polyphasic, and consisted of early and late components. The late component
was completely abolished after MST, suggesting that this component might be
due to activation of the corticospinal tract neurones by long recurrent axon
branches of dysplastic excitatory pyramidal neurones, which were cut by MST,
or by delayed, polysynaptic intracortical conduction with marked temporal dispersion.
Intracortical inhibition in the affected motor cortex was also disrupted preoperatively
and improved after MST. Postoperative recruitment order of muscle responses
to TMS was bilaterally symmetrical, indicating that MST did not interfere with
the function of the corticospinal tract neurones. The patient showed fair motor
recovery and good seizure control after the operation. These results of TMS
studies demonstrated the remarkable effectiveness of MST not only on intractable
seizure but also on abnormal motor cortical organization and hyperexcitability
in cortical dysgenesis.
PMID: 11408329 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
39: J Neurol. 2001 Jan;248(1):69-70. Related Articles, Links
Magnetic stimulation during a somatosensory-precipitated
epileptic seizure.
Meierkord H, Masuhr F, Meyer BU.
Publication Types:
* Letter
PMID: 11266026 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
40: Curr Opin Neurol. 2001 Apr;14(2):193-7. Related Articles, Links
Current trends in electroencephalography.
Blume WT.
London Health Sciences Centre-University Campus, The University of Western Ontario,
339 Windermere Road, London, Ontario, Canada N6A 5A5.
Several recent articles re-emphasize the value of clinical electrophysiology:
in localizing epileptogenesis, predicting effectiveness of epilepsy surgery,
and disclosing a mechanism of benign Rolandic epilepsy of childhood. A review
of the role of EEG in the diagnosis of epilepsy indicated that epileptiform
activity will appear in 50% of initial awake recordings of adults with epilepsy
and in 85% of subjects undergoing two recordings. This contrasts with the appearance
of spikes in only 4 of 1000 normal persons. Several studies focused on the value
of electroencephalography in extratemporal epilepsy: 62% of patients with neocortical
epilepsy had at least one localizing ictal EEG; occipital and temporal neocortical
seizures were localized in a greater proportion than frontal or parietal attacks.
Interictal spikes, if unifocal, always arose from the epileptogenic region in
a study of their seizure localizing value. Such congruence augured for better
seizure control by focal resection in two studies reviewed herein.Studies indicating
the value of interictal temporal lobe spikes and scalp-recorded seizures in
lateralising a temporal seizure focus are reviewed. One study found EEG to be
slightly more reliable for lateralization of temporal epileptogenesis than MRI.In
patients with benign Rolandic seizures, enhanced motor evoked potentials (MEPs)
were obtained from transcranial magnetic stimulation when this was applied 50-80
msec after electrical stimulation of the thumb whereas this interval inhibited
the MEP in normal subjects. This suggests that afferent cutaneous input abnormally
and synchronously activates a large population of sensory neurons; such activation
is subsequently transmitted to the motor cortex to produce the focal spikes
in this condition.Finally, advances in non-invasive technology have redefined
and limited the need for invasive monitoring in children with intractable seizure
disorders.
Publication Types:
* Review
* Review, Tutorial
PMID: 11262735 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
41: Arch Gen Psychiatry. 2001 Feb;58(2):199-200. Related Articles, Links
Erratum in:
* Arch Gen Psychiatry 2001 May;58(5):515.
Deliberate seizure induction with repetitive
transcranial magnetic stimulation in nonhuman primates.
Lisanby SH, Luber B, Finck AD, Schroeder C, Sackeim HA.
Publication Types:
* Letter
PMID: 11177122 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
42: Prog Neuropsychopharmacol Biol Psychiatry. 2000 Nov;24(8):1251-73. Related Articles, Links
Seizure models: anticonvulsant effects of ECT
and rTMS.
Post RM, Speer AM, Weiss SR, Li H.
Biological Psychiatry Branch, National Institute of Mental Health, NIH, Bethesda,
MD 20892-1272, USA.
1. A variety of enzymes, peptides, neurotrophic factors and their receptors
show complex cascades of alterations with amygdala-kindled seizure progression;
some represent compensatory adaptations that could become new targets of therapeutics.
2. Non-convulsant brain stimulation with repetitive transcranial magnetic stimulation
(rTMS) may be able to engage some of the neuro-adaptive effects of ECT without
the necessity of inducing a seizure. 3. Data from preclinical and clinical studies
raise the possibility that non-convulsant stimulation achieved by high or low
frequency rTMS may be able to alter neurotransmitters, neuropeptides, and neurotrophic
factors, leading to frequency- and region-dependent changes in neural excitability.
4. Individual depressed patients show differential responses to two weeks high
vs. low frequency rTMS, as revealed by the inverse correlation of degree of
improvement in depression achieved by these two frequencies. 5. Preliminary
data from rTMS and positron emission tomography (PET) studies reveal moderately
sustained differential effects of rTMS frequency on regional cerebral neural
activity in depressed patients. 6. These data suggest the possibility that an
individual's level of baseline rCBF or rCMRglu on PET would help predict which
rTMS frequency might be the most appropriate treatment for their depression.
Publication Types:
* Review
* Review, Tutorial
PMID: 11125852 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
43: J Child Neurol. 2000 Nov;15(11):723-8. Related Articles, Links
Central conduction time of magnetic brain stimulation
in attention-deficit hyperactivity disorder.
Ucles P, Serrano JL, Rosa F.
Clinical Neurophysiology, Miguel Servet Hospital, Zaragoza, Spain.
Twenty-seven children and adolescents aged 4 to 18 years, fulfilling the Diagnostic
and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) criteria for
attention-deficit hyperactivity disorder, were included in this study. The diagnosis
was determined by a pediatric neurologist and a psychologist examined all 27
subjects with tests that included the Wechsler Intelligence Scale for Children-Revised
(WISC-R) and reading, writing, handedness, personality, and anxiety scores.
Subjects with histories of epilepsy, head injury, drug abuse, or psychotic disorders
were excluded. Culturally based causes or emotional disorders were also excluded.
Transcranial magnetic stimulation was performed on all subjects, with recording
of the motor evoked potential at the biceps brachii. Central motor conduction
time was calculated by cervical root stimulation. Due to shape variability,
the amplitude of the motor responses was not measured in the study. The mean
value of central conduction time in the subjects was very significantly increased
(P < .001) compared to that in a group of normal controls, case-matched for
IQ, age, and sex. A central motor conduction time greater than 12 ms indicates
abnormality. A second finding in the subjects was the significant difference
of central conduction time on the side-to-side stimulation (P = .03). These
findings are correlated with delay in the maturation of the corticomotoneuronal
system and might provide neurophysiologic data for diagnosis.
PMID: 11108505 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
44: Neurology. 2000 Oct 10;55(7):1025-7. Related Articles, Links
Repetitive transcranial magnetic stimulation
does not replicate the Wada test.
Epstein CM, Woodard JL, Stringer AY, Bakay RA, Henry TR, Pennell PB, Litt B.
Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA.
The authors compared inferior frontal speech arrest from repetitive transcranial
magnetic stimulation (rTMS) with bilateral Wada tests in 17 epilepsy surgery
candidates. Although rTMS lateralization correlated with the Wada test in most
subjects, rTMS also favored the right hemisphere at a rate significantly greater
than the Wada test. Postoperative language deficits were more consistent with
Wada results. Available methods for inducing speech arrest with rTMS do not
replicate the results of Wada tests.
PMID: 11061262 [PubMed - indexed for MEDLINE]
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45: Neuroreport. 2000 Sep 28;11(14):3077-84. Related Articles, Links
Enhanced motor cortical excitability in the
unaffected hemisphere after hemispherectomy.
Shimizu T, Nariai T, Maehara T, Hino T, Komori T, Shimizu H, Hirai S, Senda
M.
Department of Neurology, Tokyo Metropolitan Neurological Hospital, Fuchu, Japan.
We evaluated motor cortical excitability of the unaffected hemisphere in three
patients with intractable epilepsy who underwent hemispherectomy, using transcranial
magnetic stimulation (TMS) and PET. TMS of the unaffected hemisphere evoked
motor responses not only in the contralateral muscles but also in the ipsilateral
ones in all the patients. A PET study in one patient showed activation of the
unaffected motor cortex by movement of either arm. All of these responses were
enhanced after the hemispherectomy, probably due to motor cortical disinhibition
by transection of the corpus callosum. The PET study also showed postoperative
activation of the premotor area of the unaffected hemisphere. These phenomena
indicate posthemispherectomy neuroplastic reorganization leading to preservation
of the motor function after the operation.
PMID: 11043527 [PubMed - indexed for MEDLINE]
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46: Epileptic Disord. 2000 Sep;2(3):137-40. Related Articles, Links
Cortical silent period following transcranial
magnetic stimulation in epileptic patients.
Ertas NK, Gul G, Altunhalka A, Kirbas D.
Bakirkoy State Hospital for Psychiatric and Neurological Diseases, Neurology
Department, Bakirkoy, Istanbul, Turkey
Cortical silent period (SP) following transcranial magnetic stimulation is mainly
due to cortical inhibitory mechanisms. SP may have a value for detecting inhibitory
mechanisms in epileptic patients with or without treatment. The aim of this
study was to evaluate the effect of both the epilepsy and the antiepileptic
medication on these inhibitory mechanisms. The subgroups studied consisted of
(a) normal subjects, (b) unmedicated epileptic patients, (c) epileptic patients
with uncontrolled seizures under medication, (d) epileptic patients with controlled
seizures under medication. SP following transcranial magnetic stimulation was
measured in all subjects. The SP values from shortest to the longest were in
the following order: 1) normal subjects; 2) epileptic patients with controlled
seizures under medication; 3) unmedicated epileptic patients; 4) epileptic patients
with uncontrolled seizures under medication. Our findings probably indicate
the enhanced interictal inhibitory mechanisms in epilepsy which is resistant
to antiepileptic medication.
PMID: 11022138 [PubMed - indexed for MEDLINE]
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47: Epilepsia. 2000 Sep;41(9):1129-38. Related Articles, Links
Early and late intracortical inhibition in juvenile
myoclonic epilepsy.
Manganotti P, Bongiovanni LG, Zanette G, Fiaschi A.
Dipartimento di Scienze Neurologiche e della Visione, University of Verona,
Italy.
PURPOSE: We investigated 15 patients with juvenile myoclonic epilepsy (JME)
by subjecting them to single and paired transcranial magnetic stimulation to
test the hypothesis that motor cortical inhibition may be abnormal in this form
of benign epilepsy. METHODS: Different conditioning paradigms of paired transcranial
magnetic stimulation were used with interstimulus intervals (ISIs) of varying
lengths (1 to 400 milliseconds) to investigate changes in balance between excitatory
and inhibitory intracortical circuits. RESULTS: Motor evoked potential (MEP)
inhibition at ISIs of 1 to 4 milliseconds was significantly lower in JME patients
than in age-matched healthy controls (p < 0.001), whereas no significant
differences in MEP inhibition were noted at long ISIs (100 to 150 milliseconds).
This pattern was observed in both hemispheres in seven of seven patients studied
bilaterally and was present in both treated and untreated patients. There were
no group differences between JME patients and controls in intracortical facilitation,
motor threshold, MEP amplitude, and cortical silent period. CONCLUSIONS: We
documented a different pattern of MEP inhibition in JME patients, suggesting
impaired functioning of inhibitory interneuronal circuits, which may account
for the hyperexcitability of the motor system in this form of epilepsy.
PMID: 10999552 [PubMed - indexed for MEDLINE]
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48: Epilepsy Res. 2000 Sep;41(2):179-89. Related Articles, Links
Motor cortex excitability in patients with focal
epilepsy.
Werhahn KJ, Lieber J, Classen J, Noachtar S.
Department of Neurology, University of Munich, Germany. werhahnk@ninds.nih.gov
We studied the excitability of the motor cortex using, transcranial magnetic
stimulation (TMS) in patients with temporal and extratemporal epilepsy. We applied
single and paired-pulse TMS to 15 patients with temporal (n = 7), extratemporal
(n = 6) and focal epilepsy lateralised to one hemisphere (n = 2). Patients had
no antiepileptic drugs in the last 48 h and were seizure free for 4 h prior
to testing. We determined the threshold for EMG responses at rest (RMT), the
cortically evoked silent period (CSSP) and intracortical inhibition (ICI, intervals
of 2-4 ms) and facilitation (ICF, 7-15 ms) and compared the results to those
obtained in 17 normal controls. ICI and ICF was reduced in both hemispheres
(P < 0.01. ANOVA) compared to the controls. In the hemisphere of seizure
origin ('abnormal') there was a reduction of ICF (P < 0.01) and normal ICI,
in the 'normal' hemisphere there was a reduced ICI (P < 0.01) and a slight
reduction of ICF (P < 0.05). ICF on the 'abnormal' side was reduced (P <
0.05) compared to the 'normal' hemisphere. RMT was increased in two patients,
but group comparison of RMT and CSSP showed no significant differences between
patients and controls. The results suggest a remote effect of epileptic activity
onto the motor cortex leading to an alteration of activity in local inhibitory
circuits.
PMID: 10940619 [PubMed - indexed for MEDLINE]
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49: Clin Neurophysiol. 2000 Aug;111(8):1346-52. Related Articles, Links
Cortical motor reorganization following early
brain damage and hemispherectomy demonstrated by transcranial magnetic stimulation.
Kastrup O, Leonhardt G, Kurthen M, Hufnagel A.
Department of Neurology, University of Essen, Essen, Germany.
BACKGROUND: Transcranial magnetic stimulation (TMS) was utilized to study 7
patients who had undergone hemispherectomy for control of longstanding intractable
epilepsy to assess cortical motor reorganization and MEP (motor evoked potentials)
ipsilateral to the remaining hemisphere. Five patients were seizure-free post-operatively.
All patients displayed a spastic hemiparesis, were able to walk, raise and bend
the paretic arm and use the paretic hand to different degrees. METHODS: We examined
MEP threshold, site of maximal response to TMS, and latency to the biceps brachii,
abductor pollicis brevis and the anterior tibial muscles using a 7 and 12 cm
diameter round coil. RESULTS: The following results were obtained: (1) No MEP
could be induced to either side by use of the small coil. (2) When using the
large coil MEP-threshold was elevated also when stimulating the non-affected
hemisphere in comparison to normal controls. (3) Ipsilateral MEP were found
to: be non-inducible in two patients, demonstrate largely increased latencies
in 3 and be identical to contralateral MEP in two patients. (4) Ipsilateral
MEP could be evoked more often in distal than proximal muscles. (5) The site
of maximal ipsilateral MEP response was found approximately 2 cm anteriorly
to that of the contralateral MEP to the non-affected side of the body (6) No
correlation was found between the degree of hemiparesis and inducability of
MEP. CONCLUSIONS: The pattern of reorganization of ipsilateral motor control
following early brain damage and hemispherectomy appears to be extremely diverse
and does not correlate with the degree of neurological impairment.
PMID: 10904214 [PubMed - indexed for MEDLINE]
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50: Clin Neurophysiol. 2000 Aug;111(8):1340-5. Related Articles, Links
Remote effects of cortical dysgenesis on the
primary motor cortex: evidence from the silent period following transcranial
magnetic stimulation.
Cincotta M, Borgheresi A, Guidi L, Macucci M, Cosottini M, Lambruschini P, Benvenuti
F, Zaccara G.
Unita' Operativa di Neurologia, Azienda Sanitaria N.10 - Firenze, Ospedale S.
Maria Nuova, Piazza S. Maria Nuova, 1, 50122, Firenze, Italy.
OBJECTIVE: In cortical dysgenesis (CD), animal studies suggested abnormal cortico-cortical
connections. Cerebral areas projecting to the primary motor cortex (M1) modulate
the cortical silent period (CSP) following transcranial magnetic stimulation
(TMS). Therefore, we used the CSP to investigate remote effects of CD on the
M1. METHODS: A detailed investigation, including single-pulse TMS and electrical
nerve stimulation, was performed in 3 consecutive adults with focal CD located
outside the M1 and in 18 controls. Two patients with unilateral CD were epileptic
and treated with anti-epileptic drugs. One patient with focal CD on both sides
had no history of seizures. Neurological examination was normal in all patients.
Recordings were made from both first dorsal interosseous muscles. RESULTS: In
CD patients, the CSP was significantly lengthened contralaterally to the affected
hemispheres. In treated patients with unilateral CD, the interside difference
of the CSP duration was also significantly increased. In contrast, excitability
threshold, peripheral and corticospinal motor conduction studies, and peripheral
as well as ipsilateral silent periods were not significantly modified. CONCLUSIONS:
Our findings indicate that focal CD outside the M1 may produce CSP modifications,
which are likely due to changes of afferent control.
PMID: 10904213 [PubMed - indexed for MEDLINE]
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51: J Neurol Sci. 2000 May 1;176(1):28-36. Related Articles, Links
Afferent and efferent excitabilities of the
transcortical loop in patients with dentatorubral-pallidoluysian atrophy.
Touge T, Ichihara N, Ishibashi T, Ikeguchi M, Sasaki I, Takeuchi H.
Third Department of Internal Medicine, Kagawa Medical University, 1750-1, Ikenobe,
Miki-cho, Kita-gun, Kagawa, Japan.
To evaluate the excitabilities of the transcortical loop in patients with dentatorubral-pallidoluysian
atrophy (DRPLA), we studied somatosensory evoked potentials (SEPs) and evoked
EMG responses (V1 and V2) in 10 patients and age-matched controls. In addition,
the facilitatory effects of somatosensory inputs on motor evoked potentials
(MEPs) were studied in four patients and controls. We observed attenuated or
prolonged cervical and subcortical potentials and prolonged middle latency components
of SEPs. The amplitudes of V2 in patients were significantly lowered compared
to those in the controls, while the amplitudes and latencies of V1 were similar
between the two groups. Since V2 was considered as a transcortical reflex, our
results suggest reduced excitabilities of the afferent pathway of the transcortical
loop in patients with DRPLA. Median nerve stimulation (MNS) 25 to 30 ms preceding
transcranial magnetic stimulation (TMS) facilitated MEPs in the thenar muscle
in two of the four patients and in the controls. The facilitation of MEPs by
MNS tended to be independent of the reduction in V2. Such a result suggests
that different neural mechanisms elicit V2 and facilitate MEPs following peripheral
nerve stimulation, although further studies are needed. The combination of SEPs,
evoked EMG responses and MEPs may be a useful technique to detect abnormalities
of input and output coordinations of the transcortical loop.
PMID: 10865089 [PubMed - indexed for MEDLINE]
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52: Brain Res. 2000 Jun 23;868(2):386-91. Related Articles, Links
Analysis of EEG data from weak-field magnetic
stimulation of mesial temporal lobe epilepsy patients.
Dobson J, St Pierre TG, Schultheiss-Grassi PP, Wieser HG, Kuster N.
Centre for Science and Technology in Medicine, Keele University, Thornburrow
Drive, Hartshill, ST4 7QB, Stoke-on-Trent, UK.
Ten patients suffering from mesial temporal lobe epilepsy were exposed to weak,
DC magnetic field stimulation following computer-controlled protocols established
in previous studies. Poisson statistical analysis of the ten patients undergoing
semi-invasive (foramen ovale) electrode monitoring reveals that for at least
one experimental protocol, application of DC magnetic fields alters interictal
epileptiform spike activity in five of ten patients. Similar results also have
been observed in the analysis of both human and rat brains by employing weak,
alternating magnetic field stimulation. Further study is necessary in order
to optimize the magnetic field exposure protocol.
PMID: 10854595 [PubMed - indexed for MEDLINE]
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53: Epilepsia. 2000 Jun;41(6):694-704. Related Articles, Links
Cortical excitability in cryptogenic localization-related
epilepsy: interictal transcranial magnetic stimulation studies.
Cantello R, Civardi C, Cavalli A, Varrasi C, Tarletti R, Monaco F, Migliaretti
G.
Neurology and *Statistics Units, Department of Medical Sciences, School of Medicine,
"Amedeo Avogadro" University, Novara, Italy.
PURPOSE: To assess whether single-and paired-pulse transcranial magnetic stimulation
(TMS) can measure the interictal brain excitability of medicated patients with
cryptogenic localization related epilepsy (CLE). Changes in the balance between
excitation and inhibition are the core phenomena in focal epileptogenesis. TMS
can assess this balance in the primary motor cortex. METHODS: We selected 18
patients with CLE and similar clinical features in whom we located the epileptogenic
area reliably, with 11 age-and sex-matched healthy controls. For both motor
cortices, we determined the threshold to TMS, the duration of the cortical silent
period, and the corticocortical inhibition and facilitation curve. RESULTS:
TMS was safe. The more antiepileptic drugs (AEDs) taken by the patients, the
higher their threshold to TMS. The silent period duration failed to show significant
changes. On paired TMS, a cluster analysis identified a homogeneous subgroup
of patients (n = 7) who showed a significantly defective corticocortical inhibition
and excess facilitation. With respect to the epileptogenic area, the phenomenon
was bilateral in four of these patients, ipsilateral in two, and contralateral
in one. The phenomenon was independent of AEDs and many other clinical variables.
However, this patient group had a higher seizure frequency and a higher proportion
of electroencephalograms (EEGs) showing interictal generalized epileptic discharges
than the rest of the patients. CONCLUSION: Paired TMS provided a valuable pathophysiologic
insight into the interictal excitatory state of the cortex in CLE. This method
can potentially supply useful prognostic clinical information.
PMID: 10840401 [PubMed - indexed for MEDLINE]
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54: Clin Neurophysiol. 2000 Jun;111(6):964-74. Related Articles, Links
Contribution of motor cortex in generation of
evoked spikes in patients with benign rolandic epilepsy.
Manganotti P, Zanette G.
Department of Neurological Sciences and Vision, Neurology Section, University
of Verona, Verona, Italy.
OBJECTIVES: Among the different kinds of rolandic epilepsy there is a form of
benign epilepsy with centrotemporal spikes (BECT) presenting the peculiar characteristic
of evoking rolandic paroxysmal activity, characterized by a spike followed by
a slow wave, using electrical stimulation of the fingers. METHODS: We evaluated
7 patients suffering from BECT presenting evoked scalp activity by electrical
stimulation of the fingers of the hand. Electrical stimulation was performed
using a pair of ring electrodes applied to the thumb. The motor evoked potentials
(MEPs) were elicited in hand muscles by transcranial magnetic stimulation (TMS)
and were conditioned by the same electrical digital stimulation producing the
evoked spikes at interstimulus intervals ranging from 10 to 200 ms. RESULTS:
Digital stimulation in epileptic patients produced an increase in MEP amplitude
substantially above the normal ranges. MEP facilitation showed a time course
overlapping the ascending phase and peak of the evoked spike, whereas no significant
MEP changes were found during the early positive peak and the descending phase
of the spike, or during the following slow wave. CONCLUSIONS: Several considerations
support the hypothesis that the short-lasting M1 facilitation is related to
the spread of an abnormal hypersynchronous discharge of the S1 neurones to functionally
related motor areas via cortico-cortical connections.
PMID: 10825702 [PubMed - indexed for MEDLINE]
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55: Neuroreport. 2000 Mar 20;11(4):701-7. Related Articles, Links
Transcranial magnetic stimulation reveals an
interhemispheric asymmetry of cortical inhibition in focal epilepsy.
Cicinelli P, Mattia D, Spanedda F, Traversa R, Marciani MG, Pasqualetti P, Rossini
PM, Bernardi G.
Fondazione Santa Lucia IRCCS, Ospedale di Riabilitazione S. Lucia, Rome, Italy.
Transcranial magnetic stimulation (TCS) was applied to both hemispheres of 16
patients affected by criptogenic focal epilepsy to evaluate the interhemispheric
symmetry of the motor cortex excitability. The amplitude of the motor evoked
potentials (MEPs) and the duration of the post-MEP silent period (SP) were measured
at threshold (THR) and at increasing TCS stimulation intensities. The THR was
significantly higher in patients than in 16 age-matched control subjects (p
< 0.01). No interhemispheric differences were found in MEP amplitude. In
controls, the correlation between SP duration and increasing TCS stimulus intensity
was linear with a symmetrical progression of the SP duration over the two hemispheres.
In patients this linear SP progression was lacking on the 'epileptic' hemisphere:
the SP duration did not increase following TCS > 40% above THR, indicating abnormal
interhemispheric asymmetry. This finding suggests a selective dysfunction of
inhibition in the epileptic hemisphere as signaled by an abnormal SP duration
in response to progressively higher TCS intensities.
PMID: 10757504 [PubMed - indexed for MEDLINE]
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56: Acta Psychiatr Scand. 2000 Mar;101(3):246-8; discussion 248-9. Related Articles, Links
Transcranial magnetic stimulation induces 'pseudoabsence
seizure'.
Conca A, Konig P, Hausmann A.
Department of Psychiatry I, Regional Hospital Rankweil, Austria.
OBJECTIVE: Several studies support the hypothesis of an antidepressive or mood-enhancing
effect of repetitive transcranial magnetic stimulation (rTMS) on depressive
patients. The most acute concern regarding rTMS is possible seizure induction;
therefore, reports on seizure during rTMS are of special significance. METHOD:
We describe a case in which high frequency rTMS over the left dorsolatero-prefrontal
cortex (DLPC) applied as an add-on antidepressive strategy may have induced
a frontal lobe complex partial seizure in a female patient affected by drug-resistant
depression. RESULTS: The epileptic seizure was self-limited, and the patient
did not report any physical sequelae. The psychopathological improvement, observed
immediately after the incident in question, did not last. CONCLUSION: In this
case train duration in rTMS, combined with drugs modulating the norepinephrine
turnover, may have contributed to the occurrence of this complex partial seizure,
which neuroanatomically seems to be localized in the DLPC.
PMID: 10721875 [PubMed - indexed for MEDLINE]