A comment on the efficacy of valproate in the treatment of partial seizures

Discrepancies in the findings of studies sponsored by the Department of Veterans Affairs (VA) in the United States and the Medical Research Council (MRC) in the United Kingdom concerning the efficacy of valproate (VPA) in controlling simple or complex partial seizures, particularly those without secondarily generalized seizures, were reviewed. It was noted that the two studies differed with respect to their subjects' pretreatment seizure frequency. The frequency of complex partial seizures before treatment was obviously greater in the VA study, where carbamazepine (CBZ) provided better seizure control than VPA. Based on other comparative and non-comparative studies as well as the author's over 20 years of experience in the use of VPA in a tertiary epilepsy clinic, it is suggested that although VPA may be effective in controlling both the secondarily generalized seizures of symptomatic localization-related epilepsies and the generalized tonic-clonic seizures of idiopathic and, if not always, symptomatic generalized epilepsies, the efficacy of VPA in controlling simple or complex partial seizures is likely limited to patients with infrequent seizures.