Inconsistent response to divalproex sodium in hemichorea/hemiballism. We report 6 patients with hemichorea/hemiballism of vascular origin who were treated with divalproex sodium (Depakote). Four of 6 responded initially. Marked improvement was seen in 2 patients only and in 1 of these hemiballism recurred despite continuing therapy. Divalproex sodium is not uniformly effective in the treatment of hemichorea/hemiballism. 