Genetic variation supports a causal role for valproate in prevention of ischemic stroke.

Among valproate users, genetically predicted favorable seizure response to valproate was associated with higher serum valproate levels and reduced ischemic stroke risk, providing causal support for valproate utility in ischemic stroke prevention. The strongest effect was found for recurrent ischemic stroke, suggesting potential dual-use benefits of valproate for post-stroke epilepsy. Clinical trials are warranted to identify populations that may benefit most from valproate for stroke prevention.