Effectiveness of clonazepan in startle-induced seizures

Five cerebral-palsied children and adolescents with severe startle epilepsy became seizure-free after clonazepan was introduced into their existing anticonvulsant drug regimens. The drug was withdrawn in one case because of side effects. Two hemiparetic patients who had startle epilepsy as the only epileptic manifestation remained permanently controlled after a mean of 34 months of continuous therapy. Reappearance of startle-induced seizures occurred after 1 and 4 years in two other patients with the Lennox-Gastaut syndrome. A possible explanation for the effectiveness of clonazepan in this form of reflex epilepsy may involve inhibition of brainstem mechanisms mediating pathologically enhanced reactions in these patients, thus avoiding secondary activation of a discharging focus in the vicinity of the motor supplementary area.