Chorea: Involuntary Dance-Like Movements

What chorea looks like

The word chorea comes from the Greek for "dance". The movements are:

• brief and irregular: each one lasts a fraction of a second
• random: they do not repeat in a set pattern, unlike a tic or tremor
• flowing: they move from the face to the hand to the shoulder without warning

Mild chorea can look like restlessness or fidgeting. People often blend a movement into a deliberate action, such as touching their hair, to disguise it (this is called parakinesia). More severe chorea interferes with walking, speech, swallowing and holding objects. Many people cannot keep their tongue out for a few seconds ("darting tongue") or keep a steady grip, which feels like milking ("milkmaid's grip"). The movements usually stop during sleep and worsen with stress.

Related terms you may see:

What causes chorea

Chorea comes from dysfunction of the basal ganglia, deep brain structures that filter unwanted movement. Causes fall into a few groups.

Inherited causes

• Huntington's disease: the best-known cause in adults. It is autosomal dominant, so each child of an affected parent has a 50% chance of inheriting it. Chorea usually starts between 30 and 50 and comes with changes in mood, behavior and thinking.
• Other genetic conditions: Huntington's disease-like syndromes, benign hereditary chorea (starts in childhood and does not progress much), neuroacanthocytosis and some spinocerebellar ataxias.
• Wilson disease: copper builds up in the liver and brain, causing tremor, chorea and dystonia in teenagers and young adults. It is treatable, so it should not be missed.

Medicines and drugs

Drug-induced chorea is one of the commonest types. Culprits include levodopa and other Parkinson's drugs, long-term antipsychotics (tardive dyskinesia), some anti-seizure drugs (phenytoin, valproate), stimulants such as amphetamines and cocaine, and estrogen in the contraceptive pill.

Autoimmune and infection-related causes

• Sydenham's chorea: a complication of rheumatic fever after a group A strep throat infection. It mainly affects children aged 5 to 15 and usually clears within months.
• Lupus and antiphospholipid syndrome: can cause chorea at any age, particularly in young women.
• Chorea gravidarum: chorea in pregnancy, often in women who had Sydenham's chorea as a child.
• Rarely, autoimmune encephalitis, HIV or other infections of the brain.

Metabolic and vascular causes

• Stroke: a small stroke in the basal ganglia can cause sudden chorea or hemiballismus on one side.
• High blood sugar: nonketotic hyperglycemia, typically in older people with poorly controlled diabetes, can cause one-sided chorea that settles once glucose is controlled.
• Other: an overactive thyroid, low or high sodium or calcium, liver failure and polycythemia vera.

Age and cause at a glance

How chorea is diagnosed

A neurologist diagnoses chorea by watching the movements. Finding the cause involves:

1. History: speed of onset, recent sore throat, pregnancy, all medicines and recreational drugs, and family history of movement disorders, early dementia or psychiatric illness.
2. Examination: looking for one-sided signs, weakness, eye movement problems, heart murmurs (rheumatic fever) and signs of liver disease.
3. Blood tests: glucose, sodium, calcium, thyroid and liver function, a full blood count, autoimmune tests (ANA, antiphospholipid antibodies), strep antibody titers in children, and copper and ceruloplasmin for Wilson disease.
4. Brain MRI: shows stroke, shrinkage of the caudate nucleus in Huntington's disease, or the bright basal ganglia seen with high blood sugar.
5. Genetic testing: a blood test can confirm Huntington's disease. Testing someone without symptoms is done only after genetic counseling.

Treatment

Treating the cause

Stopping or reducing the responsible medicine, controlling blood sugar, treating an overactive thyroid, managing lupus, or giving antibiotics to prevent further rheumatic fever can reduce or end the chorea. Chorea in pregnancy often settles after delivery.

Medicines that calm the movements

Treatment is only needed when the movements cause distress, falls, injury or problems with eating and daily tasks.

• VMAT2 inhibitors (tetrabenazine, deutetrabenazine, valbenazine): reduce dopamine release and are the main option for Huntington's chorea. They can worsen depression, so mood is monitored.
• Antipsychotics such as haloperidol, risperidone or olanzapine: also reduce chorea, and may help agitation or psychosis.
• Other options: amantadine, and for Sydenham's chorea, valproate or carbamazepine; steroids are sometimes used in severe cases.

Support and safety

Physical and occupational therapy help with balance and daily tasks. Speech and language therapists assess swallowing. Weighted cutlery, padded furniture and a high-calorie diet help people with severe chorea, who can burn a lot of energy through constant movement.

Outlook

The outlook depends entirely on the cause. Sydenham's chorea, drug-induced chorea, chorea from high blood sugar and chorea in pregnancy usually improve or resolve. Chorea after a stroke often fades over weeks to months. Huntington's disease is progressive, but treatment can keep chorea under control for years, and the main long-term challenges become thinking, mood and swallowing.

Frequently asked questions

What is chorea in simple terms?

Chorea is a pattern of involuntary movements that are quick, irregular and unpredictable, moving from one body part to another. It can look like fidgeting, restlessness or dancing. It is a sign of a problem in the basal ganglia of the brain, not a disease by itself.

Is chorea always Huntington's disease?

No. Huntington's disease is a well-known cause, but medicines, stroke, high blood sugar, lupus, pregnancy and Sydenham's chorea after a strep infection are all common causes. Many of these are treatable or temporary, which is why a full workup is needed before genetic testing.

What is the difference between chorea and a tic?

A tic is a repeated movement, often preceded by an urge, that a person can suppress for a short time. Chorea is random, does not repeat in a fixed pattern and cannot be held back. Tics usually start in childhood; chorea can begin at any age.

Can chorea go away?

Yes, often. Chorea caused by a medicine, high blood sugar, pregnancy or Sydenham's chorea usually improves once the cause is treated or passes. Chorea after a stroke frequently fades over months. Chorea from Huntington's disease does not go away but can be controlled with medicine.

Does chorea happen during sleep?

Usually not. Chorea typically disappears during sleep and gets worse with stress, excitement or concentration. Movements that continue during deep sleep suggest a different problem, such as seizures, and should be mentioned to a doctor.