Apart from animal work, disorders of the basal ganglia in humans have revealed much about their structure-function relationships. Such disorders can be classified as hyperkinetic or hypokinetic (and hyperkinetic). Hyperkinetic disorders include ballismus (uncontrolled contractions of the proximal muscles leading to violent movements of the limbs and arising from damage to the sub-thalamic nuclei) and Huntington’s chorea. The best-known hypokinetic disorder is Parkinson’s disease, and another is athetosis. Functional disturbances in the basal ganglia have also been shown to play a role in Tourette’s syndrome.
See Acetylcholine (AcH), Athetoid (or athetotiform) movements, Brain damage studies, Cerebellum (disorders), Huntington’s disease (or chorea), Parkinson’s disease, Tourette’s syndrome