Photosensitivity and epilepsy: a follow-up study.

To understand the evolution of photosensitivity and to evaluate if its disappearance is related to the response to anticonvulsant therapy, we performed a long-term study of 42 patients (17 males, 25 females; age at onset 6 years 9 months, SD 5 years 2 months, range 5 years to 12 years 1 month) who had electroencephalography (EEG) evidence of photosensitive epilepsy. Of the patients, 36 were treated with valproate (VPA) monotherapy and four received VPA in combination with other antiepileptic drugs (AEDs), which were carbamazepine and lamotrigine. Two patients were given no drugs, but treated with stimuli avoidance. All patients were investigated with EEG by using intermittent photic stimulation. The photoparoxysmal response indicated the presence of photosensitivity. At the end of follow-up, the photoparoxysmal response had disappeared in 25 patients. Thirty-three patients became seizure-free. Our study confirms that photosensitive epilepsy has a good prognosis for seizure control that is independent of the persistence or disappearance of photosensitivity.