Startle epilepsy: a clinical study.

Twelve patients with perinatal anoxic encephalopathy, 1 with encephalitis, and 1 with Down's syndrome had startle epilepsy. Hemiparesis, startle-induced seizures involving the hemiparetic side, focal electroencephalographic abnormalities, and unilateral lesions evident on computed tomographic scan were found in 6 patients, all of whom responded favorably to carbamazepine. The remaining 8 patients had severe intellectual impairment, bilateral motor deficits, generalized startle-induced seizures, diffuse and lasting electroencephalographic abnormalities, and widespread cerebral lesions evident on computed tomographic scan. Of these, 2 patients with Lennox-Gastaut syndrome responded to clonazepam, 4 others responded to valproic acid, and 2 others, with predominantly focal hemispheric lesions, improved on a regimen of carbamazepine.