Valproic acid use in pediatric partial epilepsy after initial medication failure

We retrospectively identified 46 children and adolescents with partial epilepsy, who failed prior treatment with phenytoin, carbamazepine, phenobarbital and/or primidone. All patients were subsequently treated with valproate (VPA). Outcome measurements were stratified into seizure type, simple partial seizures (SPS), complex partial seizures (CPS) or secondarily generalized seizures (SGS), or lesions detected by magnetic resonance images (MRI). The majority of the patients had a ≥ 75% reduction of seizure frequency. Complete seizure freedom was achieved in 7 (15%) patients. "Worthwhile" seizure reduction, defined as ≥ 75% decrease (but < 100%) in seizure activity, was found in 30 (65%) patients. VPA was efficacious in SPS (2/2), CPS (9/12) and SGS (26/32) patients. Patients with MRI lesions of vascular insult (6/6), mesial temporal lobe sclerosis (8/10), or malformation of cortical development (6/7) had a higher response percentage than those patients with normal MRI findings (11/15) and tumors (5/7). Although the numbers of patients used in this study were too small for statistical significance, our results suggest that VPA is a useful medication for previous medication failures in childhood partial seizures across seizure types as well as MRI lesions. There is some suggestion that a higher percentage of patients with MRI lesions may respond favorably to VPA than patients with non-lesional partial seizures and tumors. (J Pediatr Neurol 2004; 2(4): 199-203)