Ictal EEG patterns in band heterotopia.

Abstract

Band heterotopia (BH) or "double cortex" syndrome is a neuronal migration disorder resulting in a diffuse band of subcortical grey matter and variable abnormality of the overlying cortex. Patients with BH have a spectrum of psychomotor delay and seizures. Associated epileptic syndromes and interictal EEG findings have been described, but ictal EEG patterns are lacking. We describe the clinical, interictal, and ictal EEG findings in two girls with BH and intractable seizures. Ictal EEG patterns correlated well with clinical seizure types, and did not have features unique to BH. Similarly, seizure behaviors and interictal EEG findings were typical of those seen in symptomatic generalized epilepsies. Despite evidence implicating the ectopic grey matter in seizure discharges, we conclude that seizure semiology and associated ictal EEG patterns in BH are no different from those seen in other causes of symptomatic generalized epilepsies.