Electroclinical characteristics of hemimegalencephaly

Presented here are two long-term follow-up patients with hemimegalencephaly . Patient 1 had Ohtahara's syndrome, which evolved into West's syndrome. Pa tient 2 had localization-related epilepsy, which demonstrated epilepsia par tialis continua throughout the clinical course. The patients' interictal el ectroencephalograms revealed asymmetric suppression-burst patterns sometime during the clinical course: only during early infancy in patient 1 and unt il the last follow-up (at 30 years of age) in patient 2, Both patients had moderate mental and motor disturbances with persistence of seizures. Hemipl egia was progressive during early childhood. Aggravation of hemiplegia migh t be related to frequent seizures and persistent electroencephalographic ab normalities during early childhood. Although asymmetric suppression-burst p atterns are considered characteristic electroencephalographic findings In t hese cases, the duration of their appearance did not have definite prognost ic significance. (C) 1999 by Elsevier Science Inc. All rights reserved.