Chorea is an abnormal voluntary movement disorder, one of a group of neurological disorders called dyskinesias, which are caused by overactivity of the neurotransmitter dopamine in the areas of the brain that control movement. Chorea is characterized by brief, irregular contractions that are not repetitive or rhythmic, but appear to flow from one muscle to the next. Chorea often occurs with athetosis, which adds twisting and writhing movements. Chorea is a primary feature of Huntington's disease, a progressive, hereditary movement disorder that appears in adults, but it may also occur in a variety of other conditions.

The differential diagnosis of chorea includes a growing number of rare diseases. This article gives hints on clinical differences and possible laboratory investigations which may help to identify the underlying disease. The majority of hereditary chorea cases are caused by Huntington's disease. Different courses of disease can be distinguished depending on age at disease onset.

Chorea is an irregular, rapid, uncontrolled, involuntary, excessive movement that seems to move randomly from one part of the body to another. The word "chorea" comes from the Greek word for dance. The jerky movements of the feet or hands are often similar to dancing or piano playing. When chorea is severe, the movements may cause motion of the arms or legs that results in throwing whatever is in the hand or falling to the ground. Walking may become bizarre, with inserted excessive postures and leg movements.

Causes of Chorea

Sydenham chorea is one of the major signs of acute rheumatic fever. It is discussed here as a separate entity because it may be the only sign of rheumatic fever in some patients.

Huntington's chorea (HC), an incurable hereditary disorder caused by a mutation in a gene on the short arm of human chromosome 4. It is characterized by dementia and psychiatric disturbances as well as chorea.

Senile chorea, which is gradual in onset, is not associated with other causes of chorea, does not cause personality changes, and develops in people over the age of 60. At one time, senile chorea was thought to be a late-onset form of HC, but is presently considered to be the result of a different genetic mutation

Chorea may also be caused by drugs (levodopa, anti-convulsants, anti-psychotics), metabolic disorders, endocrine disorders, and vascular incidents.

Symptoms of Chorea

Swelling and inflammation (arthritis) of one or more joints that may be characterized by redness, warmth, tenderness, and pain (arthralgia) of affected joint regions. Arthritis and fever are the most common symptoms initially recognized in association with ARF.

Chorea is a neurological disorder characterized by involuntary spasmodic movements of the body. Movements are jerky and arrhythmic, and may involve the whole body. Other symptoms include muscle weakness, clumsiness, and gait disturbances.

Crocus is also a remedy in chorea with hysterical symptoms, twitching of single muscles. It corresponds well to symptoms of hysteria.

Symptoms of muscular twitchings, among which are twitchings and spasms of the eyeballs and eyelids; it has angular choreic movements and spasmodic motions of the extremities, which are not confined to one side of the body, but affect the upper half on one side of the body and the lower half on the other.

Symptoms may appear gradually or suddenly, and may include muscle weakness, hypotonia (decreased muscle tone), and clumsiness. The symptoms vary in severity--from mild cases in which there is restlessness, facial grimacing, and a slight degree of incoordination of movements, to severe cases involving involuntary movements that incapacitate the child.