The word chorea is derived from the Latin word ‘choreus’, which means dancing. Chorea is a neurological disorder which causes abnormal involuntary movements. The abnormal involuntary movements are caused due to the over activity of a neurotransmitter called dopamine in the areas of the brain which control movement. Neurotransmitters are chemical messengers which help in the transmission of nerve impulses through the nerves, in the brain.
The characteristic feature of chorea is brief, irregular contractions that are not repetitive or rhythmic, but seem to move from one muscle to the next. Chorea can be defined as "a state of excessive, spontaneous movements, irregularly timed, non-repetitive, randomly distributed and abrupt in character.” The severity of the involuntary movements can appear in the form of restlessness with mild erratic increase of gesture and expression. In severe cases, it can turn into a continuous flow of disabling, violent movements. In the initial stages, chorea can be mistaken for normal fidgetiness.
Patients with chorea are unable to maintain a sustained posture. For example, when asked to grip an object, they alternately squeeze and release it ("milkmaid's grip") or when they protrude the tongue, it often pops in and out of the mouth. When chorea occurs with athetosis, it has twisting and writhing movements as well.
Chorea is a major presenting symptom of Huntington's disease which is a progressive, and hereditary movement disorder of adults. Some other causes of chorea include Sydenham's chorea (a complication of rheumatic fever), drugs (levodopa, anti-convulsants and anti-psychotics), metabolic and endocrine disorders, and vascular incidents.
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