On the problem of diphenylhydantoin-induced seizures. An experimental approach.

Abstract

For the past ten years, the clinical literature has indicated that certain patients with epilepsy may develop increasing seizures accompanied by electroencephalographic changes in a setting of diphenylhydantoin toxicity. In addition, several patients seriously intoxicated by accidental or suicidal overdoses of diphenylhydantoin have displayed convulsive movements and opisthotonic posturing. The experimental literature indicates that toxic doses of diphenylhydantoin cause seizures in laboratory animals. In the present study electroencephalographic monitoring has been employed during acute and chronic diphenylhydantoin intoxication; seizure-like episodes, observed clinically by previous investigators, have not been accompanied by any electroencephalographic evidence of seizure activity. The electroconvulsive threshold rises during the development of acute diphenylhydantoin intoxication and is maintained at high levels during chronic intoxication. In addition, diphenylhydantoin does not worsen pentylenetetrazol-induced seizures but tends to protect against them.