Clinical and electroencephalographic abnormalities during the full duration of a sporadic hemiplegic migraine attack

Summary Electroencephalographic (EEG) abnormalities have been reported during migraine attacks but their spatial and temporal distributions are not well known. We report the temporospatial dynamics of EEG during the full duration of a migraine attack with aura in a 19-year-old woman. She experienced episodes of hemiplegic migraine since the age of 2.5 years, with right hemibody paralysis preceded by visual symptoms. She reported severe pain of the right hemibody just before hemiplegia that was enventually suggestive of possible epileptic seizure, justifying diagnostic video-EEG monitoring. Sporadic hemiplegic migraine was diagnosed in the absence of family history. EEG was normal at the beginning of visual aura. After 15 minutes, posterior slow waves appeared over the migrainous hemisphere, spreading progressively towards anterior regions: first the central region (5 minutes after onset of contralateral hemiplegia), then the frontal region and over both hemispheres. A new de novo mutation was identified in the SCN1A gene.