Causes Of Chorea: Different Types Of Chorea And Their Treatment

The term “chorea” is derived from Greek word “dance”, is used to describe irregular, unpredictable, brief, jerky movements that flit from one part of the body to another in a random sequence.

In early stages, chorea is often mistaken for normal fidgetiness.

Most common causes of chorea are:

  • Hereditary
    • Huntington’s disease
    • Benign hereditary chorea
    • Wilson’s disease
    • Leigh’s disease
    • Neuroacanthocytosis
  • Drugs– (neuroleptics, anti-parkinsonian drugs)
  • Metabolic
    • Hyperthyroidism
    • Hypothyroidism
    • Pregnancy (chorea gravidarum)
  • Infectious- Sydenham’s (rheumatic) chorea.
  • Immunological- systemic lupus erythematosus.
  • Perinatal- hypoxia and kernicterus.
  • Toxins- carbon monoxide, mercury.
  • Others- tumor, trauma, cerebrovascular disease.

Various Types Of Chorea And Their Treatment

Huntington’s disease

  • It is a progressive disorder characterized by chorea, behavioral disturbances and dementia. It is inherited in autosomal dominant pattern.
    Onset is seen in 4th or 5th decade.
  • There is no definitive treatment. Chorea may respond to haloperidol. Genetic counseling is important.

Rheumatic (Sydenham’s chorea)

  • There is manifestation of rheumatic fever. It occurs 1 to 6 months after the acute streptococcal infection and affects patients between 5 to 15 years. Girls are more affected. Distribution is most often generalized, but hemi-chorea (one-sided) may occur. Chorea progresses in intensity and gradually resolves.

Hemiballism

  • “Ballism” in Greek means “to throw”. These movements are wide in amplitude, violent and flinging in nature. When confined to one side of body it is called hemi-ballism.
    It usually follows a stroke involving contra-lateral sub-thalamic nuclei. Haloperidol and chlorpromazine is used to control the movements.

Tremors

  • It is an involuntary, regular and repetitive shaking of a body part around a fixed point.
  • Tremors are of 3 types- Resting tremors, action or postural tremors and intentional tremors.
  • Not all patients with tremors require treatment. For those whose symptoms are disabling propranolol may be recommended.

Myoclonus

  • It refers to sudden brief, shock like involuntary movement that may be caused by active muscle contraction or inhibition of ongoing muscle activity.
  • These could be single, occasional jerks or could be repetitive contractions.
  • The amplitude may range from a small contraction to a very large jerk.
  • They may occur spontaneously or in response to sudden noise, light, pin prick or touch.

Causes Of Myoclonus Chorea

  • Hereditary
  • Epileptic myoclonus
  • Symptomatic myoclonus as in Wilson’s disease, metabolic encephalopathy, Creutzfelt-Jacob disease and toxins like bismuth, drugs e.g. levedopa and tricyclic antidepressants.
  • Drugs like clonazepam and carbamazepine have been tried with limited success.

Tics

These are abrupt, transient, stereotyped, coordinated movements which are repeated at regular intervals, two characteristic features distinguish this disorder.

  • Patients usually experience an inner urge to make movement which is temporarily relieved by its performance.
  • Tics are voluntary suppressible for variable time periods.
  • Mild cases are best left alone. If tics are distressing dopamine antagonists like haloperidol may be prescribed by the doctor.