OCCIPITAL LOBE DEVELOPMENTAL MALFORMATIONS AND EPILEPSY - CLINICAL SPECTRUM, TREATMENT, AND OUTCOME

Purpose: Cortical developmental malformations (CDM) are increasingly r ecognized in association with epilepsy. We describe 10 patients (age r ange 14-35 years) with symptomatic occipital lobe epilepsy and CDM. Me thods: Neurologic, neuroophthalmologic and electrophysiologic studies were performed. Patients had MRI, SPECT, and in some cases intracrania l EEG investigators. Results: Mean age of seizure onset was 8 years, W e noted strong correlations between the presence of visual auras, the scalp EEG pattern, and the subtype of underlying pathology. Magnetic r esonance imaging (MRI) showed CDM in all patients, with polymicrogyria and focal dysplasia being the most frequent malformations. Despite th e presence of occipital lobe structural malformations in all patients, visual field deficits were present in only 2. Those who underwent cor tical resections were seizure-free or showed major improvement at a me an follow-up of 3.5 years. Conclusions: Intracranial stimulation studi es and the low frequency of pre- and postoperative deficits suggest th at some degree of cortical visual reorganization may occur in patients with occipital lobe malformations. Occipital lobe CDM should be sough t as a cause of symptomatic occipital lobe epilepsy even though they m ay become symptomatic after childhood.