Such contractile movements include dystonia, chorea, athetosis, and ballism.

In one case, before ITB the patient had an average of 10-12 ballism episodes of the right lower limb per hour.

Involuntary movements can take many forms such as ballism, chorea or dystonia and usually only affect one side of the body or one limb in particular.

When chorea is serious, slight movements will become thrashing motions; this form of severe chorea is referred to as ballism or ballismus.

Unlike ataxia, which affects the quality of voluntary movements, or Parkinsonism, which is a hindrance of voluntary movements, the movements of chorea and ballism occur on their own, without conscious effort.

Hemiballismus, sometimes called ballism, is a very rare movement disorder, classified by a decrease in activity of the subthalamic nucleus of the basal ganglia, resulting in decreased suppression of undesired movements.

This is characterized by attacks of involuntary movements (dystonia, chorea, or ballism), which are typically triggered by sudden voluntary movements, but can also be triggered by involuntary movements as well (for example, hyperventilating).

Symptoms experienced during attacks can vary and include dystonia, chorea, athetosis, ballismus, or a combination.

When chorea is serious, slight movements will become thrashing motions; this form of severe chorea is referred to as ballism or ballismus.