[Sodium valproate and cognitive function]

In patients with epilepsy, cognitive functions can be affected by several factors individually or in combination. These complex interactions between various factors have been responsible for considerable methodological problems in the assessment of the effect of individual antiepileptic drugs on cognitive functions. A discussion on the effect of sodium valproate on cognitive functions should consider three aspects: whether valproate affects cognitive functions, how possible cognitive effects of valproate compare with those of other antiepileptic drugs, and finally whether valproate has a positive psychotropic effect. A suspected specific psychotropic effect of valproate could not be confirmed. The majorities of the studies in which the cognitive effects of valproate were assessed are comparative studies with other antiepileptic drugs in treated patients; however, some studies were based on the introduction or the discontinuation of valproate monotherapy or on a comparison between a high dose and a low dose. Like other antiepileptic drugs, sodium valproate can affect cognitive functions and behavior. When valproate has been compared with other antiepileptic drugs, the results have been either equal or in favor of valproate; however, overall these cognitive and behavioral effects are rather mild also for the other antiepileptic drugs and have been slightly overrated in the past.