Occipitotemporal seizures with ictus emeticus induced by intermittent photic stimulation

We recorded occipitotemporal seizures induced by intermittent photic stimulation in three children with brain injuries, aged 10 to 13 years. All had a history of seizures and showed occipital spikes on EEG, but were seizure free and were not being treated at the time of investigation. In all, photic stimulation induced seizures in the right occipital lobe. They were followed by clinical and EEG signs suggesting infrasylvian spreading to ipsilateral mesiotemporal limbic structures and by vomiting, appearing at late stages of the attacks. Seizure spread was very slow in two patients in whom attacks lasted 16 and 25 minutes. Patients with occipital epileptiform abnormalities presenting with ictal vomiting are often diagnosed as having vague migraine-epilepsy syndromes. We conclude that vomiting can be a late ictal phenomenon resulting from temporal lobe spread of seizures originating in the occipital lobe.