SODIUM VALPROATE IN SEVERE MIGRAINE AND TENSION-TYPE HEADACHE - AN OPEN STUDY OF LONG-TERM EFFICACY AND CORRELATION WITH BLOOD-LEVELS

We performed an open prospective study of the prophylactic efficacy of sodium valproate in 56 patients among which 35 migraineurs, 7 chronic tension-type headache patients and 14 patients with combined headache s. We compared the mean number of headache days per month during a one -month-baseline period without prophylactic treatment and during the l ast month of a 6-month-treatment course. Among secondary parameters, w e assessed headache intensity adverse experiences and we measured valp roate blood levels after one and after six months of treatment. Sixty percent of migraineurs had a 75% or more improvement in the number of headache days under sodium valproate, most of the remaining attacks be ing less severe. There was no significant improvement in chronic tensi on-type headache patients and only a mild effect in patients with comb ined headaches, almost exclusively on the migraine component. Thirty p ercent of patients reported adverse effects of which none was serious: there were 3 drop-outs. We found a moderate, but statistically signif icant, correlation between efficacy and blood levels of sodium valproa te.