Curr Opin Neurol. 2003 Jun;16(3):327-31. Review.
PMID: 12858069 [PubMed - indexed for MEDLINE]
Extensive research throughout the published literature (see pulsed magnetic therapy/migraine study bibliography below) suggests there are electrophysiological abnormalities that coexist with many different types of neurological disease states which can be positively affected by magnetic therapy including;
Alzheimer's, epilepsy, Parkinson's, cluster and other headache syndromes, severe PMS and other exaggerated menstrual related symptoms, insomnia and other sleeping disorders, attention deficit disorder ADD, attention deficit hyperactivity disorder ADHD, depression, schizophrenia and other psychological disorders.Pulsed magnetic field research suggests that pulsed electromagnetic field therapy can reduce migraine as well as induce sleep and relaxation in insomniacs. Transcranial magnetic stimulation (TMS/rTMS) research has proven for decades that pulsed electromagnetic fields safely reduce anxiety and depression using magnetic fields that are hundreds, even thousands of times the magnetic field density used to produce deep, restful sleep and improved sense of wellbeing induced through EarthPulse magnetic field supplementation.
92% of EarthPulse™ clients report better sleep and recovery (due in part to their better sleep) simply by sleeping within our very subtle, proprietary pulsed magnetic field which is matched to Planet Earth's geomagnetic field density and frequencies. Curious side effects are enhanced wellbeing, substantially enhanced recovery, strength, stamina, hand-eye, balance and motor synchronization.
Published research suggests that human disorders of many types are related by electromagnetic anomalies in the brain and body. The application of pulsed electromagnetic fields of particular frequency and field density seem to be able to safely address the problem, at least in significant part.
J Headache Pain. 2006 Oct;7(5):341-6. Epub 2006 Oct 25. Links
Transcranial magnetic stimulation for migraine: clinical effects.
Clarke BM, Upton AR, Kamath MV, Al-Harbi T, Castellanos CM.
Division of Neurology, McMaster University, Hamilton, Ontario, Canada.
Acta Neurol Belg. 2003 Sep;103(3):144-54.Links
Transcranial magnetic stimulation in migraine: a review of facts and controversies.
Fumal A, Bohotin V, Vandenheede M, Schoenen J.
Departments of Neurology and Neuroanatomy, University of Liège, B-4000 Liège, Belgium.
Med
Hypotheses. 2002 Dec;59(6):703-5.
Cellular
telephones and effects on the brain: the head as an antenna and brain tissue
as a radio receiver.
Weinberger Z, Richter ED.
Jerusalem College of Technology, Jerusalem, Israel.
Headache and other neuropsychological symptoms occur in users of cellular telephones,
and controversy exists concerning risks for brain cancer. We hypothesize these
effects result from the head serving as an antenna and brain tissue as a radio
receiver.
Adv
Ther. 2001 May-Jun;18(3):101-9.
Impulse
magnetic-field therapy for migraine and other headaches: a double-blind, placebo-controlled
study.
Pelka RB, Jaenicke C, Gruenwald J.
Universitat der Bundeswehr Munchen Munich, Germany.
Headache.
1999 Sep;39(8):567-75.
Treatment
of migraine with pulsing electromagnetic fields: a double-blind, placebo-controlled
study.
Sherman RA, Acosta NM, Robson L.
Orthopedic Surgery Service, Madigan Army Medical Center, Tacoma, WA 98431,
USA.
Headache.
1998 Mar;38(3):208-13.
Initial
exploration of pulsing electromagnetic fields for treatment of migraine.
Sherman RA, Robson L, Marden LA.
Service of Orthopedic Surgery, Madigan Army Medical Center, Tacoma, Wash.
98431, USA.
| 1: | Ambrosini A, Schoenen J. | Related Articles, Links |
|
The
electrophysiology of migraine. Curr Opin Neurol. 2003 Jun;16(3):327-31. Review. PMID: 12858069 [PubMed - indexed for MEDLINE] |
|
| 2: | Schoenen J, Ambrosini A, Sandor PS, Maertens de Noordhout A. | Related Articles, Links |
|
Evoked
potentials and transcranial magnetic stimulation in migraine: published
data and viewpoint on their pathophysiologic significance. Clin Neurophysiol. 2003 Jun;114(6):955-72. Review. PMID: 12804664 [PubMed - indexed for MEDLINE] |
|
| 3: | Bohotin V, Fumal A, Vandenheede M, Bohotin C, Schoenen J. | Related Articles, Links |
|
Excitability
of visual V1-V2 and motor cortices to single transcranial magnetic stimuli
in migraine: a reappraisal using a figure-of-eight coil. Cephalalgia. 2003 May;23(4):264-70. PMID: 12716343 [PubMed - indexed for MEDLINE] |
|
| 4: | Aurora SK, Welch KM, Al-Sayed F. | Related Articles, Links |
|
The
threshold for phosphenes is lower in migraine. Cephalalgia. 2003 May;23(4):258-63. PMID: 12716342 [PubMed - indexed for MEDLINE] |
|
| 5: | Ambrosini A, de Noordhout AM, Sandor PS, Schoenen J. | Related Articles, Links |
|
Electrophysiological
studies in migraine: a comprehensive review of their interest and limitations.
Cephalalgia. 2003;23 Suppl 1:13-31. Review. PMID: 12699456 [PubMed - indexed for MEDLINE] |
|
| 6: | Mulleners W, Chronicle E, Vredeveld J, Koehler P. | Related Articles, Links |
|
Visual
cortex excitability in migraine before and after valproate prophylaxis:
a pilot study using TMS. Headache. 2003 Mar;43(3):304. PMID: 12603670 [PubMed - as supplied by publisher] |
|
| 7: | Ozturk V, Cakmur R, Donmez B, Yener GG, Kursad F, Idiman F. | Related Articles, Links |
|
Comparison
of cortical excitability in chronic migraine (transformed migraine) and
migraine without aura. A transcranial magnetic stimulation study.
J Neurol. 2002 Sep;249(9):1268-71. PMID: 12242552 [PubMed - indexed for MEDLINE] |
|
| 8: | Brighina F, Piazza A, Daniele O, Fierro B. | Related Articles, Links |
|
Modulation
of visual cortical excitability in migraine with aura: effects of 1 Hz repetitive
transcranial magnetic stimulation. Exp Brain Res. 2002 Jul;145(2):177-81. Epub 2002 May 09. PMID: 12110957 [PubMed - indexed for MEDLINE] |
|
| 9: | Battelli L, Black KR, Wray SH. | Related Articles, Links |
|
Transcranial
magnetic stimulation of visual area V5 in migraine. Neurology. 2002 Apr 9;58(7):1066-9. PMID: 11940694 [PubMed - indexed for MEDLINE] |
|
| 10: | Bohotin V, Fumal A, Vandenheede M, Gerard P, Bohotin C, Maertens de Noordhout A, Schoenen J. | Related Articles, Links |
|
Effects
of repetitive transcranial magnetic stimulation on visual evoked potentials
in migraine. Brain. 2002 Apr;125(Pt 4):912-22. PMID: 11912123 [PubMed - indexed for MEDLINE] |
|
| 11: | Mulleners WM, Chronicle EP, Vredeveld JW, Koehler PJ. | Related Articles, Links |
|
Visual
cortex excitability in migraine before and after valproate prophylaxis:
a pilot study using TMS. Eur J Neurol. 2002 Jan;9(1):35-40. PMID: 11784374 [PubMed - indexed for MEDLINE] |
|
| 12: | Mulleners WM, Chronicle EP, Palmer JE, Koehler PJ, Vredeveld JW. | Related Articles, Links |
|
Visual
cortex excitability in migraine with and without aura. Headache. 2001 Jun;41(6):565-72. PMID: 11437892 [PubMed - indexed for MEDLINE] |
|
| 13: | Aurora SK, Cao Y, Bowyer SM, Welch KM. | Related Articles, Links |
|
The
occipital cortex is hyperexcitable in migraine: experimental evidence.
Headache. 1999 Jul-Aug;39(7):469-76. PMID: 11279929 [PubMed - indexed for MEDLINE] |
|
| 14: | Mulleners WM, Chronicle EP, Palmer JE, Koehler PJ, Vredeveld JW. | Related Articles, Links |
|
Suppression
of perception in migraine: evidence for reduced inhibition in the visual
cortex. Neurology. 2001 Jan 23;56(2):178-83. PMID: 11160952 [PubMed - indexed for MEDLINE] |
|
| 15: | Cutrer FM, O'Donnell A, Sanchez del Rio M. | Related Articles, Links |
|
Functional
neuroimaging: enhanced understanding of migraine pathophysiology.
Neurology. 2000;55(9 Suppl 2):S36-45. Review. PMID: 11089518 [PubMed - indexed for MEDLINE] |
|
| 16: | Werhahn KJ, Wiseman K, Herzog J, Forderreuther S, Dichgans M, Straube A. | Related Articles, Links |
|
Motor
cortex excitability in patients with migraine with aura and hemiplegic migraine.
Cephalalgia. 2000 Feb;20(1):45-50. PMID: 10817446 [PubMed - indexed for MEDLINE] |
|
| 17: | Afra J, Ambrosini A, Genicot R, Albert A, Schoenen J. | Related Articles, Links |
|
Influence
of colors on habituation of visual evoked potentials in patients with migraine
with aura and in healthy volunteers. Headache. 2000 Jan;40(1):36-40. PMID: 10759901 [PubMed - indexed for MEDLINE] |
|
| 18: | Maertens de Noordhout A, Schoenen J. | Related Articles, Links |
 |
Transcranial
magnetic stimulation in migraine. Electroencephalogr Clin Neurophysiol Suppl. 1999;51:260-4. Review. No abstract available. PMID: 10590958 [PubMed - indexed for MEDLINE] |
|
| 19: | Aurora SK, al-Sayeed F, Welch KM. | Related Articles, Links |
|
The
cortical silent period is shortened in migraine with aura. Cephalalgia. 1999 Oct;19(8):708-12. PMID: 10570724 [PubMed - indexed for MEDLINE] |
|
| 20: | Cutrer FM, O'Donnell A. | Related Articles, Links |
|
Recent
advances in functional neuroimaging. Curr Opin Neurol. 1999 Jun;12(3):255-9. Review. PMID: 10499170 [PubMed - indexed for MEDLINE] |
|
Curr
Opin Neurol. 2003 Jun;16(3):327-31.
The electrophysiology of migraine.
Ambrosini A, Schoenen J.
Headache Clinic, INM Neuromed, IRCCS, Pozzilli, Isernia, Italy.
PURPOSE OF REVIEW: The pathophysiology of migraine is far from being understood.
Electrophysiological methods are useful to investigate peripheral and central
mechanisms underlying this disorder. The purpose of this review is to highlight
the results of electrophysiological studies published during the last year and
to examine their added value to our previous knowledge. RECENT FINDINGS: Studies
by visual and auditory evoked potentials and event-related responses suggested
that lack of habituation is the principal interictal abnormality of sensory
processing in migraineurs. Recently confirmed for somatosensory and laser-evoked
cortical potentials and for brainstem responses, it is also responsible for
the increased intensity dependence of auditory evoked potentials. This abnormality
is possibly caused by a reduced cortical preactivation level due to hypofunctioning
subcortico-cortical aminergic pathways. Although studies of cortical excitability
by transcranial magnetic stimulation have yielded conflicting results, results
obtained using habituation of pattern-reversal visual evoked potentials to explore
cortical excitability changes induced by repetitive transcranial magnetic stimulation
strongly favour the hypothesis that migraine is characterized by a decreased
level of preactivation excitability. With regard to pain mechanisms in migraine,
electrophysiological studies of trigeminal pathways using nociceptive blink
and corneal reflexes have confirmed that sensitization of central trigeminal
nociceptors occurs during the attack, and may even persist interictally. SUMMARY:
Scientific publications over the last year confirmed that electrophysiological
methods are particularly suited to unravelling some of the pathophysiological
mechanisms of migraine. To improve their future contribution, they need to be
better standardized and to be correlated with behavioural, metabolic and genetic
studies.
PMID: 12858069 [PubMed - in process]
------------------------------------------------------------------------
2: Cephalalgia. 2003;23 Suppl 1:13-31. Related Articles, Links
Electrophysiological
studies in migraine: a comprehensive review of their interest and limitations.
Ambrosini A, de Noordhout AM, Sandor PS, Schoenen J.
Headache Clinic, INM Neuromed, IRCCS, Pozzilli (Isernia),Italy.
Electrophysiological methods may help to unravel some of the pathophysiological
mechanisms of migraine. Lack of habituation is the principal and most reproducible
interictal abnormality in sensory processing in migraineurs. It is found in
evoked potential (EP) studies for every stimulation modality including nociceptive
stimuli, and it is likely to be responsible for the increased intensity dependence
of EP. We have hypothesized that deficient EP habituation in migraine could
be due to a reduced preactivation level of sensory cortices because of hypofunctioning
subcortico-cortical aminergic pathways. This is not in keeping with simple hyperexcitability
of the cortex, which has been suggested by some, but not all, studies of transcranial
magnetic stimulation (TMS). A recent study of the effects of repetitive TMS
on visual EP strongly supports the hypothesis that migraine is characterized
by interictal cortical hypoexcitability. With regard to pain mechanisms in migraine,
electrophysiological studies of trigeminal pathways using nociceptive blink
and corneal reflexes have confirmed that sensitization of central trigeminal
nociceptors occurs during migraine attacks.
Publication Types:
* Review
* Review, Tutorial
PMID: 12699456 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
3: Clin Neurophysiol. 2003 Jun;114(6):955-72. Related Articles, Links
Evoked
potentials and transcranial magnetic stimulation in migraine: published data
and viewpoint on their pathophysiologic significance.
Schoenen J, Ambrosini A, Sandor PS, Maertens de Noordhout A.
University Department of Neurology, CHR Citadelle, Blvd du XIIemede Ligne, 1-B-4000,
Liege, Belgium. jean.schoenen@chrcitadelle.be
Migraine is a disorder in which central nervous sytem dysfunction might play
a pivotal role. Electroneurophysiology seems thus particularly suited to study
its pathophysiology. We have extensively reviewed evoked potential and transcranial
magnetic stimulation studies performed in migraineurs in order to identify their
pathophysiologic significance. Publications available to us were completed by
a Medline search. Retrieved and personal data were compared with respect to
methodology and interpreted according to present knowledge on cortical information
processing. Results are in part contradictory which appears to be method-, patient-
and disease- related. Nonetheless, both evoked potential and transcranial magnetic
stimulation studies demonstrate that the cerebral cortex, and possibly subcortical
structures, are dysfunctioning interictally in both migraine with and without
aura. These electrophysiologic abnormalities tend to normalise just before and
during an attack and some of them seem to have a clear familial and predisposing
character. Besides the studies of magnetophosphenes which have yielded contrasting
results, chiefly because the method is not sufficiently reliable, most recent
electrophysiologic investigations of cortical activities in migraine favour
deficient habituation and decreased preactivation cortical excitability as the
predominant interictal dysfunctions. We propose that the former is a consequence
of the latter and that it could favour both interictal cognitive disturbances
as well as a cerebral metabolic disequilibrium that may play a role in migraine
pathogenesis. To summarize, electrophysiologic studies demonstrate in migraine
between attacks a cortical, and possibly subcortical, dysfunction of which the
hallmark is deficient habituation.
PMID: 12804664 [PubMed - in process]
------------------------------------------------------------------------
4: Curr Opin Neurol. 2002 Jun;15(3):303-9. Related Articles, Links
The
electrophysiology of migraine.
Giffin NJ, Kaube H.
Headache Group, Institute of Neurology, Queen Square, London WC1N 3BG, UK.
Migraine is currently regarded as a neurovascular disorder of trigeminal sensory
processing, generated centrally, probably at the level of the brainstem. In
the past, electrophysiological techniques have drawn no definite conclusions
on either interictal or ictal changes in migraineurs compared with controls,
largely because of methodological differences. Recently, two findings have been
shown consistently: an interictal increasing lack of habituation of evoked potentials
with a normalization at the start of the attack and strong intensity dependence
of auditory evoked potentials. These findings substantiate migraine sufferers
as having an abnormal trait interictally, with the attack characterized by a
change in the state of central processing. Exploitation of these differences
may be a useful tool to study the mechanism of action of drugs used for the
treatment of migraine.
Publication Types:
* Review
* Review, Tutorial
PMID: 12045729 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
5: Cephalalgia. 2000 Oct;20(8):714-9. Related Articles, Links
Habituation
of visual and intensity dependence of auditory evoked cortical potentials tends
to normalize just before and during the migraine attack.
Judit A, Sandor PS, Schoenen J.
Department of Neurology, Semmelweis University of Medicine, Budapest, Hungary.
Between attacks, migraine with (MO) or without aura (MA) patients show deficient
habituation of pattern-reversal visual evoked potentials (PR-VEP) and a strong
intensity dependence of auditory evoked cortical potentials (IDAP). Clinical
observations of migraine prodromes and previously published electrophysiological
studies suggest that cortical information processing may vary in close temporal
relationship to the attack. We studied PR-VEP and IDAP just before (11 MO pts),
during (23 MO, 3 MA), 1 day following (27 MO, 1 MA) and 2 days following (14
MO) a migraine attack. The results were compared with a large group of MO patients
recorded at a distance of at least 3 days from an attack (n = 66 for IDAP; n
= 39 for VEP). Patients recorded the day before the attack had on average an
habituation of -13.6+/-20.5% (mean +/- SD) between the 5th and 1st block of
100 averaged VEP responses and a flat (0.38+/-1.06 microV/10 dB) amplitude-stimulus
intensity function (ASF) slope of the auditory evoked cortical potential. Both
values were significantly different from those obtained in the attack interval
(P=0.003; P=0.020). During the attack, VEP habituation was less pronounced (-0.17+/-26.2%)
and ASF slopes remained flat (0.32+/-1.44 microV/10 dB; P=0.002 compared to
interval). During the 2 days following the attack, VEP habituation was replaced
by potentiation (+0.09+/-29.1% the 1st day; 19.5+/-45.7% the 2nd day) and ASF
slopes increased markedly (0.87+/-1.39 and 1.14+/-1.12 microV/10 dB). The normalization
of evoked cortical responses just before and during the attack, might reflect
an increase in the cortical preactivation level due to enhanced activity in
raphe-cortical serotonergic pathways.
PMID: 11167900 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
6: Clin Neurosci. 1998;5(1):10-7. Related Articles, Links
Cortical
electrophysiology in migraine and possible pathogenetic implications.
Schoenen J.
Department of Neurology, University of Liege, CHR Citadelle, Liege, Belgium.
Schoenen.J@innet.be
According to recent evoked potential studies a fundamental, probably protective,
feature of cortical information processing, i.e., response habituation during
stimulus repetition, is abnormal in migraine between attacks. The deficient
habituation is found for different sensory modalities and experimental paradigms:
pattern-reversal visual evoked potentials (same stimulus at a constant intensity),
cortical auditory evoked potentials (same stimulus at increasing intensities),
and auditory event-related potential obtained in a passive "oddball" paradigm
(novel stimulus). The abnormal information processing is an interictal cortical
dysfunction most likely due to inadequate control by the so-called "state-setting,
chemically-addressed pathways" originating in the brain stem, in particular
by the serotonergic pathway, leading to a low preactivation level of sensory
cortices. We propose that it may play a pivotal role in migraine pathogenesis
in conjunction with the reported decrease of brain mitochondrial energy reserve,
by favouring a rupture of metabolic homeostasis and biochemical shifts capable
of activating the trigeminovascular system and, thus, of producing a migraine
attack. We postulate that both the deficient habituation in information processing
and the deranged oxygen metabolism may have behavioral correlates. Which of
these abnormalities are inherited, acquired, or both remains to be determined.
Publication Types:
* Review
* Review, Academic
PMID: 9523052 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
7: Biomed Pharmacother. 1996;50(2):71-8. Related Articles, Links
Deficient
habituation of evoked cortical potentials in migraine: a link between brain
biology, behavior and trigeminovascular activation?
Schoenen J.
Department of Neurology, University of Liege, Belgium.
According to recent evoked potential studies, a fundamental, probably protective,
feature of cortical information processing, ie, response habituation during
stimulus repetition, is abnormal in migraine between attacks. The deficient
habituation is found for different sensory modalities and experimental paradigms:
pattern-reversal visual evoked potentials (same stimulus at a constant intensity),
cortical auditory evoked potentials (same stimulus at increasing intensities)
and auditory event-related potentials obtained in a passive "oddball" paradigm
(novel stimulus). The abnormal information processing is an interictal cortical
dysfunction most likely due to inadequate control by the so-called "state-setting,
chemically-addressed pathways" originating in the brain stem, in particular
by the serotonergic pathway, leading to a low preactivation level of sensory
cortices. We suggest that it may play a pivotal role in migraine pathogenesis
in conjunction with the reported decrease of brain mitochondrial energy reserve,
by favouring a rupture of metabolic homeostasis and biochemical shifts capable
of activating the trigeminovascular system and thus capable of producing a migraine
attack. We postulate that both the deficient habituation in information processing
and the deranged oxygen metabolism may have behavioral correlates. Which of
these abnormalities are inherited, acquired or both remains to be determined.
Publication Types:
* Review
* Review, Tutorial
PMID: 8761712 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
8: Clin Neurophysiol. 2000 Jun;111(6):1124-9. Related Articles, Links
Comparison
of visual and auditory evoked cortical potentials in migraine patients between
attacks.
Afra J, Proietti Cecchini A, Sandor PS, Schoenen J.
Department of Neurology Semmelweis University of Medicine, Budapest, Hungary.
OBJECTIVE: As both habituation of pattern reversal visual evoked potentials
(PR-VEP) (Schoenen J, Wang W, Albert A, Delwaide PJ. Potentiation instead of
habituation characterizes visual evoked potentials in migraine patients between
attacks. Eur J Neurol 1995;2:115-122) and intensity dependence of auditory evoked
cortical potentials (IDAP) (Wang W, Timsit-Berthier M, Schoenen J. Intensity
dependence of auditory evoked potentials in migraine: an indication of cortical
potentiation and low serotonergic neurotransmission? Neurology 1996;46:1404-1409)
were found abnormal in migraine between attacks, we have searched for intraindividual
correlations between both tests in 59 migraine patients (22 with aura [MA],
37 without aura [MO]) and in 23 healthy volunteers (HV). METHODS: Amplitude
change of the PR-VEP N1-P1 was measured between the 1st and 5th block of 50
sequential averagings during continuous stimulation at 3.1 Hz. IDAP was computed
from N1-P2 amplitudes of 100 averagings during stimulations at 40, 50, 60 and
70 dB SL. Amplitude-stimulus intensity function (ASF) slopes and amplitude changes
between 40 and 70 dB were calculated. MO and MA differed from HV in PR-VEP amplitude
change (P=0.007) and IDAP slope (P = 0.0004). RESULTS: There was no significant
correlation between VEP amplitude changes and IDAP slopes, nor between the latter
two and attack frequency or disease duration. A negative correlation was found
between the amplitude of the first block of averaged responses and potentiation
of VEP in all subject groups (P = 0.03) as well as between the amplitude of
the auditory evoked potential, at 40 dB, and the percentage of amplitude increase
between 40 and 70 dB in MO (P = 0.004) and MA (P = 0.007). ASF slopes and 40
dB amplitudes were significantly correlated only in the MA group (P = 0.002).
These results confirm the interictal deficit of habituation in cortical processing
of repetitive visual and auditory information in migraine. Since there is no
intraindividual correlation between the cortical responses to these sensory
modalities they are complementary tools for the study of migraine and may help
to identify subgroups of patients with distinct pathophysiological mechanisms.
CONCLUSIONS: The strong negative correlation between the initial amplitude of
evoked potentials and their amplitude increase during subsequent averaging confirms
that the response potentiation in migraine is likely to be due to a reduced
preactivation level of sensory cortices.
PMID: 10825720 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
9: Brain. 2002 Apr;125(Pt 4):912-22. Related Articles, Links
Effects
of repetitive transcranial magnetic stimulation on visual evoked potentials
in migraine.
Bohotin V, Fumal A, Vandenheede M, Gerard P, Bohotin C, Maertens de Noordhout
A, Schoenen J.
Department of Neurology, University of Liege, Liege, Belgium.
Between attacks, migraine patients are characterized by potentiation instead
of habituation of stimulation-evoked cortical responses. It is debated whether
this is due to increased or decreased cortical excitability. We have studied
the changes in visual cortex excitability by recording pattern-reversal visual
evoked potentials (PR-VEP) after low- and high-frequency repetitive transcranial
magnetic stimulation (rTMS), known respectively for their inhibitory and excitatory
effect on the cortex. In 30 patients (20 migraine without, 10 with aura) and
24 healthy volunteers, rTMS of the occipital cortex was performed with a focal
figure-of-eight magnetic coil (Magstim). Nine hundred pulses were delivered
randomly at 1 or 10 Hz in two separate sessions. Stimulus intensity was set
to the phosphene threshold or to 110% of the motor threshold if no phosphenes
were elicited. Before and after rTMS, PR-VEP were averaged sequentially in six
blocks of 100zztieresponses during uninterrupted 3.1 Hz stimulation. In healthy
volunteers, PR-VEP amplitude was significantly decreased in the first block
after 1 Hz rTMS and the habituation normally found in successive blocks after
sustained stimulation was significantly attenuated. In migraine patients, 10
Hz rTMS was followed by a significant increase of first block PR-VEP amplitude
and by a reversal to normal habituation of the potentiation (or dishabituation)
characteristic of the disorder. This effect was similar in both forms of migraine
and lasted for at least 9 min. There were no significant changes of PR-VEP amplitudes
after 1 Hz rTMS in migraineurs and after 10 Hz rTMS in healthy volunteers, nor
after sham stimulation. The recovery of a normal PR-VEP habituation pattern
after high-frequency rTMS is probably due to activation of the visual cortex
and the dishabituation in healthy volunteers to cortical inhibition. We conclude,
therefore, that the deficient interictal PR-VEP habituation in migraine is due
to a reduced, and not to an increased, pre-activation excitability level of
the visual cortex.
PMID: 11912123 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
10: Brain. 2003 Jun 23 [Epub ahead of print]. Related Articles, Links
Lack
of habituation causes high intensity dependence of auditory evoked cortical
potentials in migraine.
Ambrosini A, Rossi P, De Pasqua V, Pierelli F, Schoenen J.
Headache Clinic, INM Neuromed, Pozzilli (Isernia), Italy.
Migraineurs are characterized interictally by lack of habituation, or even potentiation,
of cortical evoked potentials during repetitive stimulation and by a strong
intensity dependence of auditory evoked potentials (IDAP). To determine whether
these two features of sensory processing are interrelated, we have studied them
simultaneously on the same recordings of auditory evoked potentials (AEPs).
AEPs were obtained at four different stimulation intensities in 14 patients
suffering from migraine without aura (MO) and 14 healthy volunteers (HV). For
each intensity, 120 trials were averaged off-line globally and over four sequential
blocks of 30 trials. IDAP was expressed by the amplitude/stimulus intensity
function (ASF slope) for global and block averages. Habituation was calculated
as the percentage amplitude variation between the first and fourth blocks for
each stimulus intensity. The IDAP slope for global averages was higher in MO
(1.05 +/- 0.27 micro V/10 dB) than in HV (0.64 +/- 0.45 micro V/10 dB) (P =
0.008), but IDAP slopes for block averages were greater in MO only at the fourth
block (P = 0.048). First block amplitudes tended to be lower in MO, except at
80 dB. There was a potentiation of AEP amplitudes at every stimulus intensity
in MO, contrasting with habituation in HV. IDAP slopes were negatively correlated
with mean habituation percentages in pooled data from patients and controls
(r = -0.610; P = 0.0006). This study confirms that IDAP is higher in migraineurs
than in healthy controls. It also shows that the AEP habituation is replaced
by potentiation at all stimulus intensities. The negative correlation found
between IDAP and habituation suggests that the latter is able to have a strong
influence on the former and perhaps even lead to it. In migraine, the habituation
deficit amplifies the IDAP and may thus be the causal functional abnormality.
We propose that it is due to a decreased pre-activation level of sensory cortices,
a hypothesis also supported in this study by the lower amplitude of first AEP
blocks in patients.
PMID: 12821515 [PubMed - as supplied by publisher]
------------------------------------------------------------------------
11: Neurosci Lett. 2001 Jun 22;306(1-2):132-4. Related Articles, Links
Reduced
gating of middle-latency auditory evoked potentials (P50) in migraine patients:
another indication of abnormal sensory processing?
Ambrosini A, De Pasqua V, Afra J, Sandor PS, Schoenen J.
Headache Clinics - IRCCS Neuromed via Atinense, 18, I-86077 , Pozzilli (Isernia),
Italy.
Habituation of cortical evoked responses to repetitive stimuli is reduced in
migraine between attacks. To explore another aspect of information processing,
we measured auditory sensory gating. The amplitude of the P50 response to the
second of two homologous stimuli was significantly less reduced in migraineurs
than in healthy volunteers. This lack of auditory sensory gating may be due
to a hypofunction of monoaminergic subcortico-cortical pathways, which is also
supposed to cause the interictal deficit of cortical habituation to repetitive
stimuli.
PMID: 11403975 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
12: Neurology. 1996 May;46(5):1404-9. Related Articles, Links
Intensity
dependence of auditory evoked potentials is pronounced in migraine: an indication
of cortical potentiation and low serotonergic neurotransmission?
Wang W, Timsit-Berthier M, Schoenen J.
Department of Neurology, University of Liege, Belgium.
Migraine is associated with stimulus hypersensitivity, increased evoked cortical
responses, and abnormal 5-HT levels in peripheral blood. We studied cortical
auditory evoked potentials (AEPs) between attacks in 35 patients suffering from
migraine without aura (MO, n = 25) or with aura (MA, n = 10) and in 25 healthy
volunteers. Binaural tones were delivered at 40, 50, 60, and 70 dB sensation
level (SL) in a pseudorandomized order. The intensity dependence of the auditory
N1-P2 component was significantly greater in MO (p = 0.003) and MA (p = 0.02)
patients than in healthy controls, resulting in a much steeper amplitude/stimulus
intensity function slope. When three sequential blocks of 40 averaged responses
were analyzed at the 40- and 70-dB SL intensities, N1-P2 amplitude decreased
in second and third blocks at both intensities in controls, but increased in
migraineurs, a difference that was significant in both blocks for the 70-dB
SL stimulus. The strong interictal dependence of AEPs on stimulus intensity
may thus be due to potentiation (instead of habituation) of the response during
repetition of the high-intensity stimulation. In concordance with previous studies
of visual evoked potentials, these results confirm that migraine is characterized
between attacks by an abnormality of cortical information processing, which
might be a consequence of low 5-HT transmission and favor cortical energy demands.
PMID: 8628490 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
13: Cephalalgia. 2000 Nov;20(9):804-20. Related Articles, Links
Visual,
long-latency auditory and brainstem auditory evoked potentials in migraine:
relation to pattern size, stimulus intensity, sound and light discomfort thresholds
and pre-attack state.
Sand T, Vingen JV.
Department of Clinical Neurosciences, Trondheim University Hospital, Norwegian
University of Science and Technology. trond.sand@medisin.ntnu.no
We aimed to estimate primary sensory evoked potential (EP) amplitude, amplitude-intensity
functions and habituation in migraine patients compared with healthy control
subjects and to investigate the possible relation to check size, sound and light
discomfort thresholds, and the time to the next attack. Amplitudes of cortical
visual evoked potentials (VEP, check size 8' and 33'), cortical long latency
auditory evoked potential (AEP NIP1; 40, 55 and 70 dB SL tones) and brainstem
auditory evoked potential (BAEP wave IV-V; 40, 55 and 65 dB SL clicks) were
recorded and analysed in a blind and balanced design. The difference between
the response to the first and the second half of the stimulus sequence was used
as a measure of habituation. Twenty-one migraine patients (16 women and five
men, mean age 39.3 years, six with aura, 15 without aura) and 22 sex- and age-matched
healthy control subjects were studied (18 women and four men, mean age 39.5
years). Low sound discomfort threshold correlated significantly with low levels
of BAEP wave IV-V amplitude habituation (r = -0.30, P = 0.05). VEP an AEP amplitudes,
habituation, and amplitude-intensity function (ASF) slopes did not differ between
groups when ANOVA main factors were considered. Control group VEP habituation
was found for small check stimuli (P = 0.04), while potentiation was observed
for medium sized checks (P = 0.02). The eight migraine patients who experienced
headache within 24 h after the test tended to have increased BAEP wave IV-V
ASF slopes (P = 0.08). This subgroup did also have a significant VEP habituation
to small checks (P = 0.04). No correlation was found between different modalities.
These results suggest that: (i) VEP habituation/potentiation state and brainstem
activatio state may depend on the attack-interval cycle in migraine; (ii) VEP
habituation/ potentiation may depend on spatial stimulus frequency; (iii) phonophobia
(and possibly photophobia) may depend more on subcortical (brainstem) function
than on cortical mechanisms; (iv) low cortical preactivation in migraine could
not be confirmed; (v) EP habituation and ASF analysis may reflect sensory modality-specific,
not generalized, central nervous system states in migraine and healthy control
subjects.
PMID: 11167910 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
14: Headache. 2000 Jan;40(1):30-5. Related Articles, Links
Prophylactic
treatment of migraine with beta-blockers and riboflavin: differential effects
on the intensity dependence of auditory evoked cortical potentials.
Sandor PS, Afra J, Ambrosini A, Schoenen J.
Neurology Department, CHR Citadelle, University of Liege, Belgium.
OBJECTIVE: To investigate the influence of different pharmacological treatments
on the intensity dependence of auditory evoked cortical potentials in migraineurs.
BACKGROUND: Between attacks, patients with migraine show abnormalities in cortical
information processing and decreased brain mitochondrial energy reserve. Both
are most probably relevant for migraine pathogenesis, and they could be differentially
modified by prophylactic drug therapy. Design.-The intensity dependence of the
auditory evoked cortical potentials is, on average, increased in migraine. We
have studied this intensity dependence in 26 patients before and after a 4-month
period of prophylaxis with beta-blockers (n = 11, all migraine without aura;
metoprolol or bisoprolol) or riboflavin (n = 15, migraine without aura: 13,
migraine with aura: 2). Recordings were performed at least 3 days before or
after an attack. RESULTS: After the treatment with beta-blockers, the intensity
dependence of the auditory evoked cortical potentials was significantly decreased
(before: 1.66+/-1.02 microV/10 dB; after: 0.79+/-1.06 microV/10 dB, P=.02).
The decrease in intensity dependence was correlated significantly with clinical
improvement (r = .69, P = .02). There was no change in intensity dependence
after riboflavin treatment (before: 1.80+/-0.81 microV/10 dB; after: 1.56+/-0.83
microV/10 dB, P = .39), although the majority of patients showed improvement.
CONCLUSIONS: These results confirm that beta-blockers and riboflavin act on
two distinct pathophysiological mechanisms. Combining both treatments might
enhance their efficacy without increasing central nervous system side effects.
PMID: 10759900 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
15: Eur J Neurol. 2002 May;9(3):227-32. Related Articles, Links
Median
nerve somatosensory evoked potentials in migraine.
Ozkul Y, Uckardes A.
Department of Neurology, Faculty of Medicine, University of Harran, Sanliurfa,
Turkey. yasarozkul@yahoo.com
In visual evoked potential studies, habituation during stimulus repetition with
the same stimulus at a constant intensity has been found to be abnormal in migraineurs
between attacks. The purpose of this study was to investigate habituation of
somatosensory evoked potentials (SEPs) and the effects of migraine on them.
Eighty-five subjects were included in the study: 30 healthy volunteers (HVs)
and 55 migraineurs [30 with migraine without aura (MO), 25 with migraine with
aura (MA)]. During continuous stimulation at 3 Hz, four blocks of 100 responses
were sequentially averaged of Erb's point (N9), cervical (N13), and cortical
(N20) median nerve SEPs. Mean amplitude changes in the second, third and fourth
blocks are expressed as percentages of the first block. There was habituation
to N13 and N20 in the second, third and fourth blocks in HVs. In the migraine
groups, there was no habituation; on the contrary, potentiation was found. This
potentiation was statistically significant only in the second blocks for N13
(MO P=0.007, MA P=0.01 versus HVs). However, in both migraineur groups, the
rate of N20 potentiations was statistically significant versus that in HVs for
all blocks (all P < 0.05). It is concluded that whilst physiological habituation
occurs in HVs for cervical and cortical SEPs, in migraine patients there is
an interictal deficit of habituation of this sensory modality.
PMID: 11985630 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
16: Neuroreport. 1999 Apr 26;10(6):1235-8. Related Articles, Links
Familial
influences on cortical evoked potentials in migraine.
Sandor PS, Afra J, Proietti-Cecchini A, Albert A, Schoenen J.
Neurology Department, University of Zurich, Switzerland.
Cortical information processing in migraine patients is impaired between attacks,
showing deficient habituation of pattern-reversal visual evoked potentials (VEP),
and strong intensity dependence of auditory cortical evoked potentials (IDAP).
This could be a genetic trait as certain genetic patterns are known for evoked
potentials in healthy subjects. We investigated VEP habituation and IDAP in
20 pairs of migraineurs made up of parents and their children. Using a Monte-Carlo
statistical method, we selectively assessed vertical familial influences. VEP
habituation and IDAP were abnormal in both parents and children. However, similarity
was far more pronounced between related pairs than between unrelated pairs.
Familial influences are highly significant in determinants of cortical information
processing in migraineurs, hence supporting the important role of genetic factors.
PMID: 10363931 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
17: Headache. 2000 Jan;40(1):36-40. Related Articles, Links
Influence
of colors on habituation of visual evoked potentials in patients with migraine
with aura and in healthy volunteers.
Afra J, Ambrosini A, Genicot R, Albert A, Schoenen J.
Department of Neurology, Semmelweis University of Medicine, Budapest, Hungary.
OBJECTIVE: To investigate whether colored glasses influence the habituation
of visual evoked potentials. BACKGROUND: We have previously shown that during
pattern-reversal stimulations lasting 2 minutes the amplitude of the visual
evoked potential increases in migraine with and without aura between attacks,
whereas it decreases in healthy volunteers. Red light was found to increase
visually evoked EEG fast activity only in children with migraine with aura.
Wearing rose-tinted glasses for 4 months decreased attack frequency in parallel
with a reduction of the visually evoked EEG fast activity. METHODS: We compared
the change in amplitude of the visual evoked potential using five different
tinted glasses in 12 patients with migraine with aura and in 10 healthy volunteers.
During continuous stimulation at 3.1 Hz, five blocks of 50 responses were sequentially
averaged using red, yellow, green, blue, and grey glasses and without glasses
in a random order and analyzed in terms of latencies and N1-P1 amplitudes. Amplitude
changes were calculated for each block by comparison with the first block in
every condition and analyzed statistically using Zerbe's method. RESULTS: In
healthy volunteers, the visual evoked potential amplitude increased with red
glasses compared to without glasses (P = .05) or with green glasses (P = .03).
In patients with migraine with aura, no significant difference was detected
using colored glasses. Our findings in healthy volunteers are in line with earlier
reports of increased excitability of the human visual cortex when exposed to
red light. The lack of such a pattern in patients with migraine with aura suggests
that the visual cortex is interictally hypoexcitable rather than hyperexcitable,
which is consistent with studies of transcranial magnetic stimulation.
PMID: 10759901 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
18: Headache. 2002 Jul-Aug;42(7):582-7. Related Articles, Links
Effects
of fluoxetine on habituation of pattern reversal visually evoked potentials
in migraine prophylaxis.
Ozkul Y, Bozlar S.
University of Harran, Faculty of Medicine, Department of Neurology, Sanliurfa,
Turkey.
OBJECTIVE: To investigate the effects of fluoxetine in migraine prophylaxis
on habituation of visually evoked potentials. BACKGROUND: Habituation of pattern
reversal visually evoked potentials was found to be abnormal in migraine between
attack, and this abnormality was most likely due to serotonergic pathway dysfunction
in the brain stem. METHODS: One hundred nineteen subjects were included in the
study: 40 healthy volunteers and 79 migraineurs not taking any prophylactic
migraine medication (44 without aura and 35 with aura). Visually evoked potentials
in migraineurs were recorded in the headache-free interval. Amplitude change
of the visually evoked potentials (N1-P1) was measured between the first and
fifth block of 50 sequential averagings during continuous stimulation at 3.1
Hz. All migraineurs were placed on fluoxetine 20 mg/day for prophylaxis of migraine.
One month later, visually evoked potentials were recorded again. RESULTS: Mean
amplitude changes in the fifth block expressed as percentages of the first block
were -13.4% +/- 19.2% in healthy volunteers, 9.8% +/- 23.3% in migraine without
aura, and 4.4% +/- 8.7% in migraine with aura during the baseline period. The
difference was significant between migraineurs and healthy volunteers (both
P= 0.0001), but not between migraineur groups. After treatment, amplitude changes
were -9.3% +/- 14.5% in migraine without aura and -10.1% +/- 11.5% in migraine
with aura. Habituation pattern tended to normalize with prophylactic treatment,
and mean amplitude changes were not significant between migraineurs and healthy
volunteers (both P = 0.4). CONCLUSIONS: We concluded that the fluoxetine prophylaxis
corrects the interictal deficit of habituation in migraineurs.
Publication Types:
* Clinical Trial
* Controlled Clinical Trial
PMID: 12482209 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
19: Brain. 1998 Feb;121 ( Pt 2):233-41. Related Articles, Links
Visual
evoked potentials during long periods of pattern-reversal stimulation in migraine.
Afra J, Cecchini AP, De Pasqua V, Albert A, Schoenen J.
Department of Neurology, University of Liege, Belgium.
We have previously shown that during repetitive pattern-reversal stimulation,
lasting 2 min, the amplitude of the visual evoked potential (PR-VEP) increases
in migraineurs when tested interictally whereas it decreases in healthy control
subjects. According to Sappey-Marinier et al. (J Cereb Blood Flow Metab 1992;
12: 584-92) habituation of the PR-VEP in normal subjects is maxima after 12
min, at a time when there is a decrease of stimulation-enhanced lactate levels
in the occipital cortex. We have therefore compared PR-VEP during long periods
of repetitive stimulation in healthy control subjects (n = 25) and in patients
suffering from migraine without (n = 25) and with aura (n = 15) between attacks.
During uninterrupted stimulation at 3.1 Hz VEPs were sequentially averaged in
blocks of 100 responses for a total duration of 15 min and analysed in terms
of latencies and peak-to-peak amplitudes of N1-P1 and P1-N2 peaks. Amplitude
changes from the baseline were calculated for each block, by comparison with
the first block, and analysed statistically using Zerbe's method. The N1-P1
and P1-N2 amplitudes in the first block tended to be lower in migraineurs than
in healthy control subjects. During the 15 min of stimulation, amplitudes of
both components progressively decreased in control subjects, but remained stable
in both groups of patients. The difference between patients and control subjects
proved to be significant (P < 0.05). The neurophysiological data were not
correlated with clinical features such as attack frequency or duration of illness.
These results are yet another demonstration in migraine of an interictal habituation
deficit in cortical information processing, which might favour lactate accumulation
in sensory cortices during sustained activation.
PMID: 9549502 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
20: Cephalalgia. 2002 Feb;22(1):48-53. Related Articles, Links
A
neural network model of sensitization of evoked cortical responses in migraine.
Thomas E, Sandor PS, Ambrosini A, Schoenen J.
Research Center for Cellular and Molecular Neurobiology, University of Liege,
Belgium. ethomas@ulg.ac.be
Migraine patients show abnormalities of cerebral electrophysiology that manifest
themselves mainly during the attack interval. Cortical-evoked potentials of
migraineurs fail to habituate to repetitive presentations of visual stimuli,
and the amplitude of components of their auditory cortical-evoked potentials
have a higher dependence on the stimulus intensities than in healthy subjects.
A computer model of a neural hetwork has been developed that is able to reproduce
both these neurophysiological dysfunctions. It predicts a positive correlation
between the magnitudes of both these dysfunctions. The model also offers an
explanation of why mutations in the same ion channel gene with opposite consequences
on channel function, e.g. P/Q Ca2+ channels in migraine, may lead to similar
electrophysiological abnormalities.
PMID: 11993613 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
21: Funct Neurol. 2000;15 Suppl 3:68-72. Related Articles, Links
From
neurophysiology to genetics: cortical information processing in migraine underlies
familial influences--a novel approach.
Sandor PS, Afra J, Proietti Cecchini AP, Albert A, Schoenen J.
Department of Neurology, CHR Citadelle, University of Liege, Belgium.
Migraine patients show impaired cortical information processing between attacks
with deficient habituation of pattern-reversal visual evoked potentials (VEP),
and strong intensity dependence of auditory cortical evoked potentials (IDAP).
This could be a genetic trait as certain genetic patterns are known for evoked
potentials in healthy subjects. VEP-habituation and IDAP were studied in 40
migraine patients, i.e. pairs of 20 parents and their children. We developed
a novel approach based on Monte Carlo statistics to selectively assess vertical
familial influences. Both groups, parents and children, were characterized by
abnormal VEP-habituation and IDAP. However, similarity between related pairs
was far more pronounced than similarity between unrelated pairs. Assessed with
a novel statistical approach, familial influences proved to be highly significant
in determining cortical information processing in migraineurs, thus supporting
the important role of genetic factors.
Publication Types:
* Clinical Trial
* Randomized Controlled Trial
PMID: 11200803 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
22: Cephalalgia. 1998 Jun;18(5):261-5; discussion 241. Related Articles, Links
Interictal
potentiation of passive "oddball" auditory event-related potentials in migraine.
Wang W, Schoenen J.
Department of Neurology, University of Liege, Belgium.
We have studied habituation of the P3a component of the passive "oddball" auditory
event-related potential which reflects automatic processing of a "novel" stimulus
in 24 patients suffering from migraine without aura and in 21 healthy volunteers.
Three blocks of responses to 160 standard and to 40 novel tones were sequentially
averaged at Cz and analyzed for latencies and peak-to-peak amplitudes. Latencies
of components N1 and P2 elicited by standard tones and of components N1, P2,
N2, and P3a elicited by novel tones were not significantly different between
sequential blocks or between subject groups, nor were mean N1-P2 amplitudes.
The N2-P3a amplitude tended to be lower in migraine, but not significantly so.
The most striking result in migraineurs was a significant potentiation of N2-P3a
in successive blocks, contrasting with an habituation in controls. Our previous
evoked- and event-related potential studies and the present one suggest that
deficient habituation, or even potentiation, represents interictally a fundamental
dysfunction of cortical information processing in migraine, which might increase
energy demands and play a role in etiopathogenesis.
PMID: 9673805 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
23: Rev Neurol (Paris). 2001 Apr;157(4):365-75. Related Articles, Links
[Clinical
and pathophysiological contribution of event-related potentials used to study
migraine headache]
[Article in French]
Legrain V, Janne P, Laloux P, Ossemann M, Dupuis M, Reynaert C.
Departement de psychologie clinique, Faculte de Psychologie et des Sciences
de l'Education, Universite Catholique de Louvain, Louvain-la-Neuve. legrain@clap.ucl.ac.be
Event-related potentials are electric brain manifestations evoked by mental
activities. This neurophysiological technique is able to describe temporal succession
of cognitive processing and allows to measure the neurobiological correlates
of each cognitive activity. The evoked potentials of the oddball paradigm and
the Contingent Negative Variation (CNV) are also concerned by clinical applications
in neuropsychiatry, in neurology and in psychopharmacology. In the case of migraine,
the studies with CNV recorded between migraine attacks are characterized by
two major phenomena, cerebral hyperreactivity and lack of habituation to repetitive
stimuli. From cognitive point of view, this can be interpreted as a difficulty
from migraine sufferers to adapt their information-processing to environmental
constraints. From neurological point of view, this trouble is related with dysregulation
of norepinephrin and serotonin ascending pathways. Studies with the oddball
paradigm potentials remain non consistent. The mismatch between different methodologies
could explain such a lack of consistency. The neurophysiological studies have
contributed to new physiopathological hypothesis of migraine. Those hypothesis
reveal that a shift in the brain metabolic homeostasis could be the common factor
of migraine attacks. The clinical contribution of event-related potentials is
of little use in the diagnosis of migraine. But two purposes have been suggested:
the differential diagnosis between common migraine and tension-type headaches
and the monitoring of beta-blocking agents prophylaxis.
Publication Types:
* Review
* Review, Academic
PMID: 11398007 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
24: Cephalalgia. 2000 Sep;20(7):621-31. Related Articles, Links
Olfactory
and trigeminal event-related potentials in migraine.
Grosser K, Oelkers R, Hummel T, Geisslinger G, Brune K, Kobal G, Lotsch J.
Department of Experimental and Clinical Pharmacology and Toxicology, University
of Erlangen Nurnberg, Erlangen, Germany.
BACKGROUND: Trigeminal/neuronal hyperexcitability and spreading depression activating
the trigemino-vascular system are discussed in migraine-pathophysiology. This
study investigated trigeminal and olfactory event-related potentials in migraineurs.
METHODS: Nasal chemosensitivity was assessed in 19 female migraineurs with or
without aura > 72 h before or after an attack and in 19 healthy females employing
event-related cortical potentials (ERPs) after specific trigeminal stimulation
of nasal nociceptors with short pulses of CO2, and specific olfactory stimulation
with H2S. Odour thresholds and odour identification performance were also tested.
RESULTS: Migraineurs exhibited greater responses to trigeminal stimulation,
indicated by significantly larger ERP amplitudes N1. In contrast, olfactory
ERP amplitudes P1N1 were significantly smaller in migraineurs. A leave-one-out
classification procedure on the basis of these two parameters assigned 76.3%
cases correctly. The olfactory ERP amplitude discriminated better between groups
than trigeminal ERPs (71.1 vs. 68.4% correct classification). CONCLUSIONS: Our
data suggest trigeminal hyperexcitability in migraineurs. A general increase
of nasal chemosensitivity is not supported because of smaller olfactory ERP
amplitudes in migraineurs. Olfactory ERPs discriminate better than trigeminal
ERPs between migraineurs and controls, emphasizing the significance of the olfactory
system in migraine.
PMID: 11128819 [PubMed - indexed for MEDLINE]
------------------------------------------------------------------------
25: Brain. 1999 Jun;122 ( Pt 6):1147-55. Related Articles, Links
Visual
evoked potentials in migraine patients: alterations depend on pattern spatial
frequency.
Oelkers R, Grosser K, Lang E, Geisslinger G, Kobal G, Brune K, Lotsch J.
Department of Experimental and Clinical Pharmacology, University of Erlangen-Nurnberg,
Germany. rieke_oelkers@med.uni