There three disorders are very similar and they belong to a group of disorders called the hyperkinectic disorders that also include dyskinesia and dystonia. They describe abnormal involuntary non-stereotypical movement disorders. As they are pretty similar it is very important to differentiate them and for a better understanding of these conditions you might need the specialist assistance of a neurologist.
From the very beginning it’s important to understand that all three disorders involve abnormal involuntary non-stereotypical movement. The difference consists in the muscles affected, speed and style.
Chorea involves rapid, non-stereotypical,jerky, involuntary, repetitive, dance-like movements. The moves involve the distal muscle group more than the proximal.
Unlike chorea, athetosis is a slow non-stereotypical, repetitive, involuntary, writing movement that usually affects the upper limbs.
Ballismus is also a rapid non-stereotypical, involuntary, repetitive and relatively more violent move that affects the proximal muscle group more than the distal.
Many times athetosis and chorea occur together and that is called choreoathetosis.
The involuntary movements might merge into semipurposeful or purposeful acts that could mask them.
Chorea is a progressive neurological disorder that is caused most often by Huntington’s disease. Rheumatic fever can also cause what is called the Sydenham’s chorea. Rarely, it might appear during pregnancy. The type of chorea that appears during pregnancy is called chorea gravidarum. Other causes might involve Wilson’s disease, neuroacanthocytosis and Transmissible spongiform encephalopathies.
As there is no cure for the disease there is no standard course of treatment and is symptomatic. The treatment depends on the type of chorea and there are a few medicines that can control it.
In the case of Huntington’s-related chorea the supportive treatment uses Tetrabenazine. In the case of Sydenham’s chorea the treatment involves valproic acid, Haloperidol and carbamazepine. If Wilson’s disease is causing chorea the treatment will involve chlorpromazine, haloperidol and pimozide.
The athetosis is usually caused by Huntington’s disease or marbling. In rare cases it is caused by trauma or stroke. Sometimes it might be caused by complications at birth especially neonatal jaundice and intranatal asphyxia. There are meny treatments used to help people with athetosis and most often drugs are used but sometimes surgery might be required.
The most common drugs used to treat athetosis are haloperidol, tetrabenazine, congentin, thiopropazate, artane and diazepam. The surgery might involve cutting a part of the posterior spinal roots or the removal of a part of the cerebral motor cortex. Surgery can produce immediate effects and is very beneficial on short term but they are not lasting too long. Retraining movements for the affected person is also a part of the treatment of athetosis.
Hemiballismus is a very rare disorder which can result from many various causes such as amyotrophic lateral sclerosis, stroke, vascular malformations, tuberculomas, traumatic brain injury, nonketotic hyperglycemia, neoplasms, demyelinating plaques and complications from HIV infections.
The treatment focuses on anything that causes the manifestations and symptoms of the disorder and it might include dopamine blockers, ITB therapy, botulinum injections, anticonvulsants, antipsychotics, tetrabenazine or functional neurosurgery.
Because the disorder is very rare the researchers and specialists know very little about it and there many unanswered questions. For an instance they try to explain the differences between this disorder in animals and humans. Also they try to understand why certain treatments help people with hemiballismus when they are very likely to do more harm.