Hemiballism Definition, Symptoms, Causes, Treatment | Hemiballismus vs Chorea

Hemibalism is a form of chorea characterized by rigorous and frequent movements of the limbs on one side of the body. Less often, both sides (biballismus) and legs (paraballismus) can be affected. Unlike chorea, the movements are intermittent during waking and the overwhelming involvement of the proximal muscles in their  their flailing nature.

However, the difference is not obvious because proximal ballismic movements may exist along with distal chorea, symptoms may be intermittent in more severe cases, and in many patients a change of ballismus to chorea can be seen readily or in response to treatment.

Hemibalism is a one sided ballism, a disorder of a frequent hyperkinetic movement that has a large amplitude with vigorous irregular movements. Hemibalism overlaps with clinical hemichorea ("violent chorea"). The hemiballismus-hemichorea is sometimes used to reflect this overlap. Hemiballismic states may cause loss of normal muscle tone.

Neuroanatomically, hemobalism is most commonly associated with lesions of the contralateral subthalamic nucleus of Luys or efferent pathways, although there are separate reports of its outward appearance with diseases of the caudal nucleus, globus pallidus, thalamus, and even with ipsilateral lesions. Neuropathologically, vascular events like ischemia and haemorrhage are common underlying causes of hemibalism.

Hemiballism Symptoms

Ballism is characterized by rigorous, high amplitude, waving like movements primarily by the activity of the proximal appendicular muscles of the shoulder and pelvis. Movements cease during sleep. There is a reduction in muscle tone. These symptoms are exposed unilaterally with a lesion in the subthalamic nucleus in contralateral position.

Since clinical ballism is almost always happening on the one side only and is usually due to a vascular accident, it is also known as hemiballism. Symptoms associated with dysfunction of the basal ganglia are usually observed bilaterally. However, as hemiballism, lesions on one side appear on other side, as the basal ganglia output is directed to the ipsilateral cerebral cortex, whose descending pathways predominantly innervate lower motoneurons on the contralateral side.

Hemiballism Causes

Some causative factors include occupational lesions, inflammation due to encephalitis, systemic lupus erythematosus,  demyelination, metabolic causes like hyperosmolal non ketogenic hyperglycemia, infection like toxoplasmosis , medicines especially oral contraceptives and head trauma.

Pathophysiological, hemibalism is believed to be the result of reduced conduction of the short path within the basal ganglia thalamocortical motor chain (as well as other involuntary movements such as hyperkinetic choreoathetosis). Hemiballismus associated with vascular system improves spontaneously, but drug therapy with neuroleptics may be beneficial. Other drugs that are sometimes useful include anti-psychotic drugs and anticonvulsant drugs.

Hemiballism Treatment

In an acute period when movements are most destructive and potentially harmful, some cases need treatment. Neuroleptics have long been identified as effective and remain the first choice among most clinicians, but no specific drug has been identified as superior to others. Clozapine has been reported to be useful, when other neuroleptics have failed.

Presynaptic dopamine-depleting medications  have also been reported to be beneficial. Others have been reported that are useful for the management of Hemiballism include valproic acid, gabapentin, topiramate, sertraline, and combinations of neuroleptics. Those patients who are not responding to psychotic drugs or other medications functional surgery might be the next option.