This scale gives scientists and clinicians a way to compare patients and determine the range of the disorder.The name hemiballismus literally means "half ballistic", referring to the violent, flailing movements observed on one side of the body. Causes
In examining the causes of hemiballismus, it is important to remember that this disorder is extremely rare. While hemiballismus can result from the following list, just because a patient has one of these disorders does not mean they will also experience hemiballismus. Stroke
Hemisballismus as a result of stroke occurs in only about 0.45 cases per hundred thousand stroke patients. Even at such a small rate, stroke is by far the most common cause of hemiballismus. A stroke causes tissue to die due to a lack of oxygen resulting from an impaired blood supply. In the basal ganglia, this can result in the death of tissue that helps to control movement. As a result, the brain is left with damaged tissue that sends damaged signals to the skeletal muscles in the body. The result is occasionally a patient with hemiballismus. Traumatic brain injury
Hemiballismus can also occur as a result of a traumatic brain injury. There are cases in which survivors of assault or other forms of violence have developed hemiballismus. Through these acts of violence, the survivors brain has been damaged and the hemiballistic movements have developed. Amyotrophic lateral sclerosis
This disease causes neuronal loss and gliosis, which can include the subthalamic nucleus and other areas of the brain.
In about half of the monkeys, the hemiballismus continued until the monkey died.Other scientists have also worked on this perplexing disorder and have found that the symptoms can be induced by injecting kainic acid or ibotenic acid into the subthalamic nucleus. I. Hamada and M.R. DeLong found that by using these chemicals, they could destroy only four percent of the subthalamic nucleus and still see hemiballistic movements. However, the abnormal movements would usually disappear within four to five hours even though it did not appear as though the damaged tissue had healed. This suggests that the subthalamic nucleus is plastic enough to adapt to small amounts of damage in order to resume normal function. See also
Movement disorders

References


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