Phenytoin toxicity: A cause of reversible monoplegia1

Abstract

Phenytoin sodium (Dilantin), a frequently used anticonvulsant, has many well-recognized side effects. Of these, neurological ones are prominent and, when present, usually consist of ataxia, nystagmus, or dysarthria. Phenytoin toxicity in patients with previous strokes may present as a “re-stroke” syndrome. This paper reports a rare but recognizable complication in a patient in whom reversible monoplegia, a focal neurological deficit, developed during long-term phenytoin therapy for grand mal seizures.