[Acute polyneuropathy caused by diphenylhydantoin intoxication (author's transl)]

In a 34-year-old epileptic male who had been treated for more than ten years with an average of 300 mg diphenylhydantoin and 200-300 mg phenobarbitone daily severe status epilepticus occurred which could only be controlled with high doses of diphenylhydantoin and phenobarbitone intravenously. During this treatment a severe mainly motor polyneuropathy occurred acutely which was more pronounced in the distal parts of the legs, and cerebellar symptoms were noted at the same time. The neuropathy largely regressed during the following year whereas the cerebellar symptoms persisted. There is evidence for direct toxic damage of peripheral nerves due to diphenylhydantoin. Phenobarbitone in high doses inhibits degradation of diphenylhydantoin competively. In this patient it very likely contributed towards the development of sever intoxication leading to neurological defects.