Abstracts

Band heterotopia (BH) is a severe form of migrational abnormality that presents with mental retardation and epilepsy. This condition may have a genetic basis. The associated epileptic syndrome, neuroimaging and interictal EEG findings have been described, but there are few reports about ictal EEG patterns.
The aim of this study is to describe the clinical, neuroradiological and EEG (interictal/ictal) features of patients with BH. CCF MRI database (1999-2004) was searched to identify patients with diffuse bilateral BH who underwent Video-EEG evaluation. MRI findings were confirmed. Details about their clinical presentation, seizure semiology and interictal/ictal EEG findings were reviewed from the charts. Four patients were identified with diffuse bilateral BH. All of them had mental retardation and medically refractory seizures with multiple seizure types. One patient had positive history for epilepsy.
The most common seizure type was Generalized Tonic-Clonic Seizures (in all patients), followed by dialeptic seizures in 3 patients. 2 Patients had atonic, one each had myoclonic or complex motor seizures. Interictal epileptiform discharges were generalized or multiregional involving both hemispheres in three patients and one did not show interictal epileptiform activity. Ictal recording showed generalized EEG seizure pattern in two of the cases, while two patients showed either regional (1) or lateralized (1) EEG seizure patterns. Band heterotopias with diffuse bilateral MRI abnormality may present with regional ictal patterns on EEG. Epilepsy surgery may be an option for this subgroup of patients with medically refractory seizures, however better tools (imaging, stereotactic EEG) would be needed to map the ictal onset zone. Genetic testing and counseling should be considered as part of the clinical management. (Supported by Department of Neurology. The Cleveland Clinic Foundation.)