A fuzzy feeeling in the head

35 yo epileptic pt came to dr office c/o a fuzzy feeeling in the head .P/E show bidirectional horozontal nystegmus. the most likely cause
is?

1 poorly controled epilepsy
2 vit. b12 def.
3 alcoholism
4 phenytoin excess
5 subdural hematoma

At therapeutic doses, phenytoin produces horizontal gaze nystagmus, which is harmless but occasionally tested for by police as a marker for alcohol intoxication (which can also produce nystagmus). At toxic doses, patients experience sedation, cerebellar ataxia, and ophthalmoparesis, as well as paradoxical seizures. Idiosyncratic side effects of phenytoin, as with other anticonvulsants, include rash and severe allergic reactions.