Electrophysiological
Findings in Migraine
Szanyi J., Kuba M., Kremláček J., Chlubnová J., Waberžinek G.
Ústav patologické fyziologie, UK, Praha, Lékařská fakulta Hradec Králové, Neurologická klinika FN, Hradec Králové |
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Summary:
Our objective was to contribute to the elucidation of changes in cerebral function of patients suffering
from migraine. Twenty-six patients were examined where migraine was diagnosed (5 with aura and 21
without aura), and as a control group 27 healthy volunteers. The patients were examined during the
intervals between attacks, at least 72 hours after an attack. In addition to standard pattern-reversal
VEPs the authors used also two variants of motionnset VEPs and cognitive stimulation. Visually
evoked cognitive potentials were tested either by using the „oddball“ paradigm – differentiation of
coherent and non-coherent motion signalized by pressing a button or by so-called emotional passive
event-related potentials were involved (passive follow up of alternate projection of pictures of the
normal and electronically destroyed face in a pseudorandom order). The investigation revealed a normal reaction of the patients during stimulation of primary (striate) and associati ve extrastriate areas
of the visual cerebral cortex (pattern reversal and motion-onset VEPs resp.). On examination of
cognitive potentials significant changes were found only when so-called passive cognitive potentials
were used, i.e. the reactions of the migraine patients did not have a smaller amplitude of the reaction
to frequent (non-target) stimuli as compared with rare (target) stimuli, as it is usually the case in
cognitive evoked potentials. The authors evaluated also the frequency spectrum of the EEG at rest, the
parameters of which were normal in patients with migraine. The same reaction to a rare and frequent
stimulus in the patients can be interpreted as defective inhibition of attention (habituation) during
stimulation by an insignificant stimulus in a migrainous brain which supports some already existing
data of this type recorded in the literature.
Key words:
migraine, visual evoked potentials (VEP), cognitive evoked potentials (ERP)
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