Hemiballism is often a challenging movement disorder to manage, especially in severe cases. Outlined herein are some of the salient points that may help the clinician understand better the history, clinical spectrum, causes, pathophysiology, differential diagnoses, diagnostic workup, prognosis, and latest medical and surgical treatment options for hemiballism. A clinical vignette is also provided to illustrate a classic case of hemiballism.
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• Hemiballism refers to flinging movements of the upper and lower limbs on 1 side of the body.
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• Onset of hemiballism is usually acute, and is most commonly due to ischemic stroke, hemorrhage, autoimmune disorders, medications, metabolic abnormalities (most commonly hyperglycemia), neoplasms, or infections.
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• Treatment is usually symptomatic, unless a reversible cause can be identified and corrected (eg, hyperglycemia, infections, drugs, or metabolic abnormalities).
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• Drug therapy usually involves use of neuroleptics or antiepileptic agents.
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• Medically refractory hemiballismus may be amenable to deep brain stimulation surgery.
Historical note and terminology
"Ballism,” (meaning "to throw" in Greek) refers to violent, irregular flinging limb movements. It constitutes part of the spectrum of chorea (meaning “to dance”) and is a result of proximal muscle contraction. There are several types of ballism, depending on the distribution of movements. The most common form is “hemiballism,” which involves flinging movements of the upper and lower extremities on 1 side of the body. Ballism confined to 1 extremity is referred to as “monoballism.” The term “paraballism” describes ballistic movements in both lower limbs, whereas “biballism” or “bilateral ballism” refers to movements in both sides of the body.
Clinicopathologic and experimental studies in Rhesus monkeys linked lesions of the subthalamic nucleus with contralateral hemiballism. However, hemiballism can also result from lesions of the thalamus, neostriatum, or cerebral cortex. Hemiballism/hemichorea has also been observed in Parkinson disease patients who have undergone subthalamotomy or subthalamic deep brain stimulation (61). However, the ballism or chorea in these patients is usually short-lived and improves with reduction of levodopa dosage. Thus, it is believed that normal individuals (those with a physiologically normal subthalamic nucleus) are prone to ballism with subthalamic nucleus lesioning, whereas Parkinson disease patients (with an abnormal hyperactive subthalamic nucleus) are not.