A case of a 19-year-old mentally-retarded female with an unusual form of seizures induced by eye closure is reported from the Universities of Toronto and Calgary, Canada. She developed drop attacks at age 2 years and eye fluttering seizures with altered consciousness soon afterwards. Generalized tonic-clonic seizures coincided with the introduction of valproic acid therapy at age 13 years. Clobazam controlled the grand mal, but multiple absence seizures and status persisted, despite trials with numerous antiepileptic drugs. The voluntary act of eye closure was a trigger for seizure activity, but visual input was an inhibitor. Unless visual input was prevented by allowing the eyes to close, seizures did not occur. Darkness alone was insufficient to elicit a seizure. The EEG seizure pattern consisted of generalized high-amplitude beta activity alternating with delta, and typical spike-and-wave activity was absent. [1]
COMMENT. Seizures induced by eye closure are of two types: 1) those related to movement of the eyelids and occurring in photosensitive patients; and 2) a non-photosensitive type with scotosensitive epilepsy triggered by darkness alone or by obstruction of central visual fixation. The above patient required a combination of these two mechanisms for seizure induction.