Chorea

Not to be confused with Korea.

For the ancient Greek dance, see Choreia. For other uses, see Chorea (disambiguation).

Chorea
Classification and external resources
Specialty
ICD-10	G25.5
ICD-9-CM	333.5
DiseasesDB	16662
eMedicine	neuro/62
Patient UK	Chorea
MeSH	D002819

Chorea (or choreia, occasionally) is an abnormal involuntary movement disorder, one of a group of neurological disorders called dyskinesias. The term chorea is derived from the Greek word χορεία (=dance; see choreia), as the quick movements of the feet or hands are comparable to dancing.

The term hemichorea refers to chorea of one side of the body, such as chorea of one arm but not both (analogous to hemiballismus).

Presentation

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

Chorea can occur in a variety of conditions and disorders.

• Chorea is a primary feature of Huntington's disease, a progressive neurological disorder.
• Twenty percent (20%) of children and adolescents with rheumatic fever develop Sydenham's chorea as a complication.
• Chorea gravidarum is rare type of chorea which is a complication of pregnancy.
• Chorea may also be caused by drugs (levodopa, anti-convulsants, anti-psychotics), metabolic disorders, endocrine disorders, and stroke. The relationship between chorea and L dopa administration seems to be dependent on blood concentrations of the drug in the body
• Wilson's disease, a genetic disorder that leads to toxic levels of copper in the body
• Transmissible spongiform encephalopathies: A group of neurodegenerative diseases such as Creutzfeldt-Jakob disease and Kuru, caused by prions.
• Neuroacanthocytosis, a genetic disorder that may affect the blood, brain, peripheral nerves, muscle and heart. Common features include peripheral neuropathy, cardiomyopathy and hemolytic anemia. Other features include limb chorea, facial tics, other oral movements (lip and tongue biting), seizures, a late-onset dementia and behavioral changes.
• Gluten sensitivity more recently has been attributed to a possible underlying cause of Chorea.
• Rett syndrome, which is a genetic disorder in young girls, also causes movements of chorea in the hand or facial muscles.

Types

Huntington’s disease

This is a type of chorea that is inherited, meaning the phenotype is displayed in generation after generation. Generally, the choreic movements accompanied by the mental disorder do not skip a generation, making it a dominant trait. Huntington's disease includes the generic traits of chorea such as the progressive tremors which affect the head and limbs, and increasing mental deterioration. However, this disease can also consist of just some of these traits and to varying degrees. It has also been observed that chorea differs in families depending on their specific backgrounds, which can be expected based on its heritability. Huntington’s chorea usually accompanies other diseases depending on the family line. Other diagnoses such as epilepsy, infantile convulsions, meningeal inflammations, hydrocephaly, mental handicap, and tics occurring mostly in small families are joined with chorea. This information leads doctors and scientists to believe that the families that are susceptible to inheriting chorea are also more likely to have nervous or mental troubles.

Sydenham's chorea

Sydenham’s chorea is an acquired version of chorea. This type is increasingly rare and it may be partially due to penicillin, improved social conditions, and/or a natural reduction in the bacteria ( Streptococcus ) it has stemmed from. While chorea is known for its cause of involuntary movements, the psychological symptoms precede this acquired chorea and may be relapsing and remitting. They include: emotional lability, obsessive-compulsive behavior, cognitive defects, personality change, or attention deficit and hyperactivity. However, the hereditary and acquired types of chorea are generally have the same effects on their victims.

Chorea gravidarum

This type of chorea simply refers to choreic symptoms that occur during a women’s pregnancy. In 1900, an average 1 in 300 cases were recorded. Most cases are a reappearance of Sydenham's chorea in the primary hormonal period of the pregnancy but it can also be caused by the use of oral contraceptives. A history of acute rheumatic fever is also a very likely cause of gravidarum chorea. Some women experience chorea during their following pregnancies and several cases have been described in which attacks occurred in three, four and even five pregnancies. If left untreated, the disease resolves in 30% of patients before delivery but, in the other 70%, it persists. The symptoms then progressively disappear in the next few days following the delivery.

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.

Form	Treatment
Huntington's-related	A common treatment is dopaminergic antagonists, although treatment is largely supportive. Tetrabenazine is the only FDA approved drug for the treatment of Huntington's Disease related chorea.
Sydenham's chorea	Haloperidol, carbamazepine and valproic acid. Usually involves antibiotic drugs to treat the infection, followed by drug therapy to prevent recurrence.
Chorea gravidarum	haloperidol, chlorpromazine alone or in combination with diazepam, also pimozide can also be used.
Wilson's disease	Reducing levels of copper in the body using D-penicillinamine, trientine hydrochloride, tetrathiomolybdate, and other chelating agents
Drug-induced chorea	Adjusting medication dosages.
Metabolic and endocrine-related choreas	Treated according to their causes.

See also

• Choreoathetosis
• Dancing mania

External links

• Chorea Gravidarum~clinical at eMedicine