IDIOPATHIC PHOTOSENSITIVE OCCIPITAL LOBE EPILEPSY

We studied 10 neurologically normal patients (8 females, 2 males) aged 8-30 years (mean 17 years) who had recurrent episodes of visually ind uced occipital seizures, Television and computer screens were the main triggers. Seizure onset occurred between the ages of 5 and 17 years ( mean 11 years). All seizures were stimulus related and began with elem entary visual symptoms, followed in most patients by a slow clustering of cephalic pain, epigastric discomfort, and vomiting, with either no rmal or only mildly impaired responsiveness. EEG features included nor mal background activity, occipital spikes and waves, and a photoparoxy smal response which could be occipital, generalized, or both. Four pat ients also showed spontaneous generalized epileptiform abnormalities, and 3 had rolandic spikes. An Oz electrode was critical in identifying epileptiform activity in some patients. Complete seizure control was achieved in most patients with monotherapy, although occasional stimul us-related seizures occurred in 3 patients who showed a wider range of photosensitivity. These patients have an idiopathic localization-rela ted epilepsy with age-related onset and specific mode of precipitation . Although this type of epilepsy has been reported previously, it has remained underrecognized, probably because it is difficult to differen tiate clinically from migraine or from nonreflex childhood idiopathic occipital epilepsy.