Interictal and postictal contingent negative variation migraine without aura

Cortical hyperexcitability is thought to explain the more enhanced continge nt negative variation (CNV) amplitudes and impaired CNV habituation that ha ve been found during the interictal period in migraine without aura. These CNV characteristics have been shown to normalize to the level of healthy co ntrols during an attack. This study aimed to replicate the interictal findi ngs, and additionally examine whether migraineurs show reduced CNV amplitud es during the postattack period. Of 12 patients with migraine without aura and their sex- and age-matched healthy controls, CNV characteristics were r ecorded once in an interictal period, once during the postattack period wit hin 30 hours after an attack that was treated with sumatriptan, and once af ter an attack that was treated with habitual nonvasoactive medication (coun terbalanced), The present results did not confirm the enhanced CNV early an d late wave amplitudes or impaired habituation, and cortical hyperexcitabil ity that have previously been reported in the interictal period in patients with migraine without aura. During the postattack period, a decrease in CN V early and late amplitudes was found but only after sumatriptan use. This reduction in CNV amplitudes was most prominent over the frontal cortex and could reflect cortical hypoexcitability, possibly related to a suppression of central catecholaminergic activity by sumatriptan.