We report on an 18-month-old girl with a seizure frequency of five/day, rec
eiving an antiepileptic polytherapy consisting of primidone, clonazepam and
phenytoin. Following discontinuation of clonazepam and primidone, the pati
ent has been seizure-free under monotherapy for 2 years and shows marked de
velopmental progress. Possible mechanisms of this paradoxical effect of ant
iepileptic drugs and the implications for antiepileptic therapy are discuss
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