[Recurrent acute dyskinesia as the sole manifestation of phenytoin poisoning].

A 20 year-old epileptic female patient was admitted because of recurrent dyskinesias of 3 months duration. She was receiving phenobarbital, phenytoin (PHT) and clonazepam. PHT dosage had been increased 4 months earlier. Clinical examination and CT scan gave normal results. PHT plasmatic levels were 42 micrograms/ml on admission and there were no other symptoms of PHT toxicity. PHT-induced dyskinesias usually occur together with severe encephalopathy and/or clinical or paraclinical evidence of basal ganglia damage and/or other evidence of PHT toxicity, none of which were present here.