Hemiballism is an uncommon movement disorder that presents with unilateral flinging movements of the limbs. It varies considerably in intensity and severity—often in its acute phase it can be of sufficient severity to present as a true emergency. It is most classically associated with ischemic lesions to the subthalamic nucleus (STN), although the majority of cases involve basal ganglia structures outside the STN. An important recently described association is with diabetes, during crises of severe non-ketotic hyperosmolar hyperglycemia. Pathophysiology is related to abnormal firing patterns in the globus pallidus interna, with intermittent firing bursts followed by pauses during which movements occur. The key treatment is anti-dopaminergic therapy, either with dopamine blockers such as neuroleptics or with dopamine depleters such as tetrabenazine. In extreme cases, functional neurosurgery can be performed; either lesioning or deep brain stimulation of the globus pallidus can be considered the treatments of choice. Most patients respond well to medical treatment and spontaneous resolution is common.
KeywordsBasal Ganglion Deep Brain Stimulation Globus Pallidus Subthalamic Nucleus Sodium Valproate
Movement_Disorders_Emergencies_C12.mov (77,617 KB)
- 27.Ranawaya R, Lang AE. Neurological emergencies in movement disorders. In: Weiner W, editor. Emergent and urgent neurology. 1st ed. Philadelphia: J.B. Lippincott; 1992. p. 277–319.Google Scholar