Transient hemichorea/hemiballismus associated with new onset hyperglycemia

Objective:To describe three patients suffering from transient hemichorea/he miballismus associated with hyperglycemia, review previous reports and prop ose a possible pathophysiological explanation for this phenomenon. Results: Our original cases and previously reported ones reveal a uniform syndrome: mostly female patients (F/M ratio of 11/2), 50-80 years old, usually with no previous history of diabetes mellitus (9/13), develop choreic or ballist ic movements on one side of the body over a period of hours. Serum glucose levels are elevated. In most of the patients, a lowering of the blood sugar level reverses the movement disorder within 24-48 hours. Conclusions: We b elieve that the combination of a recent or old striatal lesion (causing inc reased inhibition of the subthalamic nucleus) and hyperglycemia (causing de creased GABAergic inhibition of the thalamus) may be responsible for the ap pearance of this unilateral hyperkinetic movement disorder. Undiagnosed dia betes mellitus should always be suspected in patients who develop hemiballi stic or hemichoreic movements. When hyperglycemia is detected and corrected , the movement disorder usually resolves within two days and may not requir e symptomatic therapy with dopamine receptor antagonists.