Ictal blindness and status epilepticus amauroticus.

Five cases of ictal blindness are presented. All are documented to be ictal by simultaneous EEG monitoring during the period of blindness. In three cases, the blindness was complete; in two, it manifested as a homonymous hemianopia. Three cases (including the two with hemianopia) were secondary to vascular lesions; one case was due to a metastatic lesion; and there was one case of idiopathic epilepsy. Age ranged from 13 to 74 years. In all cases, the blindness was reversible with anticonvulsant therapy. All cases but one lasted from hours to days, meeting a criterion of "status epilepticus amauroticus." In the literature, ictal blindness is seldom reported and even less often documented. Unexplained cortical blindness might represent unrecognized seizure activity more often than is appreciated.