Epilepsy and photosensitivity.

In a series of 2053 cases of epilepsy studied 3.9% were found to have some form of photosensitive epilepsy. The mean age of onset was 14.9 years for males, 11.8 years for females. In the age group of 6-10 years there was a definite male preponderance. In 48.2% cases the seizures were caused by watching television and in 7.4% they were precipitated by sunlight or electric lights. Primary generalized tonic clonic seizures were seen in 44.4% cases and 34.6% had secondary generalized seizures. E.E.G. was normal in 60% cases, while 18.8% had nonspecific dysrhythmias, 2.1% hypersynchronization during the interictal period with spike and sharp wave complexes. A family history of photosensitive epilepsy was present in 14.1% cases.