Migraine in childhood - are periodically occurring migraine attacks related to dynamic changes of cortical information processing?

Amplitudes and habituation of contingent negative variation (CNV) were anal yzed in relation to spontaneously occurring migraine attacks in ten childre n suffering from migraine without aura. Recording took place during feedbac k training and instrumental conditioning of slow brain potentials. Both the amplitude of the early CNV component and its habituation deficit increase during the 5 days prior to a migraine attack, with maximum abnormalities th e day before the ictal episode. Abrupt reduction of the amplitude and norma lization of the CNV habituation were observed during the attack. This study provides evidence for neurophysiological periodicity in young migraineurs and emphasizes that the time relative to the migraine attacks must be consi dered in studies of juvenile migraine during the headache-free period. (C) 2000 Published by Elsevier Science Ireland Ltd. All rights reserved.