Chorea

Chorea is characterized by brief, semi-directed, irregular movements that are not repetitive or rhythmic, but appear to flow from one muscle to the next. These 'dance-like' movements of chorea often occur with athetosis, which adds twisting and writhing movements. Walking may become difficult and include odd postures and leg movements. 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. Thus, chorea is said to be a hyperkinetic movement disorder. When chorea is serious, slight movements will become thrashing motions; this form of severe chorea is referred to as ballism, or ballismus. ==Causes==

Huntington's disease Huntington's disease is a neurodegenerative disease and most common inherited cause of chorea. The condition was formerly called Huntington's chorea but was renamed because of the important non-choreic features including cognitive decline and behavioural change. Other genetic causes Other genetic causes of chorea are rare. They include the classical Huntington's disease 'mimic' or phenocopy syndromes, called Huntington's disease-like syndrome types 1, 2 and 3; inherited prion disease, the spinocerebellar ataxias type 1, 3 and 17, neuroacanthocytosis, dentatorubral-pallidoluysian atrophy (DRPLA), brain iron accumulation disorders, Wilson's disease, benign hereditary chorea, Friedreich's ataxia, mitochondrial disease and Rett syndrome. Acquired causes The most common acquired causes of chorea are cerebrovascular disease and, in the developing world, HIV infection—usually through its association with cryptococcal disease. systemic lupus erythematosus, antiphospholipid syndrome, thyrotoxicosis, polycythaemia rubra vera, and gluten ataxia. ==Treatment==

There is no standard course of treatment for chorea. Treatment depends on the type of chorea and the associated disease. Although there are many drugs that can control it, no cure has yet been identified. == History ==

Historically, choreas like Huntington disease and Sydenham's chorea were called Saint Vitus' dance, related to a series of social phenomena of the same name. ==See also==