Photosensitive occipital lobe epilepsy: A report on three cases

The photosensitive idiopathic occipital lobe epilepsy (PIOLE) was recently recognized by the ILAE Task Force (Engel, 2001) as a new syndrome belonging to the group of reflex epilepsies. It occurs between four and eighteen years, in normal subjects, often with family antecedents, as occipital seizures, sometimes followed by autonomic signs and generalization. The Interictal EEC abnormalities are scarce but the reaction to intermittent photic stimulation (IPS) is constant. The triggering factors can be TV, video-games, and IPS. The authors report three children with photo-induced occipital seizures, characterized by simple visual hallucinations. Two of them presented with a typical PIOLE and simple focal occipital seizures were recorded during IPS. The third one was atypical, because of the co-existence of an absence epilepsy in the first childhood and of the presence of slight signs of perinatal hypoxia-ischemia in the MRI. The presentation of the two cases classified as PIOLE allows us to confirm this epilepsy type of which the frequency is probably under-estimated. In the third case, even if the symptomatic nature of the epilepsy cannot be completely exclude, it is interesting to underline the association between an idiopathic generalized epilepsy and a reflex occipital lobe epilepsy, which could suggest a genetic combination already discussed in the literature.