Results of a retrospective study in 30 patients indicate that, contrary to the findings of some earlier studies,
valproate monotherapy is highly effective in the treatment of
partial seizures, especially those that become secondarily generalized. In 22 of these 30 patients (73 percent),
valproate monotherapy either abolished
seizures (12 patients) or reduced their frequency by at least 51 percent (10 patients), whereas eight patients experienced minimal or no reduction in seizure frequency. All these patients had previously experienced treatment failure with
carbamazepine,
phenytoin, or
phenobarbital--either alone or combined--because of lack of efficacy or unacceptable side effects. In these patients, failure to have a response to
valproate therapy appeared to be related to the type of seizure (
simple partial seizures alone/
complex partial seizures alone, without secondarily
generalized tonic-clonic seizures) and longer duration of uncontrolled
seizures. Although these results cannot be generalized to all patients with
partial seizures, they do indicate that a double-blind randomized trial of
valproate in patients with all types of
partial seizures is warranted.