Transitory and permanent visual field defects induced by occipital lobe seizures.

Visual field defects are rarely associated with epilepsy. We report two patients with a long history of cryptogenetic occipital epilepsy. Both patients suffer complex partial crises accompanied by concentric reduction of the visual field followed, in the first one, by a prolonged left homonymous hemianopsia, and in the second one, by a permanent right inferior quadrantopsia. Occipital and occipito-temporal epileptic activity has been registered between seizures in both patients, and in one patient also during the seizure itself. Differential diagnosis has been considered, especially with migraine.