Chorea, Choreoathetosis

Chorea, Choreoathetosis

Chorea is an involuntary movement disorder characterized by jerky, restless, purposeless movements (literally dance-like) that tend to flit from one part of the body to another in a rather unpredictable way, giving rise to a fidgety appearance. There may also be athetoid movements (slow, sinuous, writhing), jointly referred to as choreoathetosis. Severe proximal choreiform movements of large amplitude ("flinging") are referred to as ballism or ballismus. When, as is often the case, such movements are confined to one side of the body they are referred to as hemichorea-hemiballismus. There may be concurrent abnormal muscle tone, either hypotonia or rigidity. Hyperpronation of the upper extremity may be seen when attempting to maintain an extended posture.

The pathophysiology of chorea (as for ballismus) is unknown; movements may be associated with lesions of the contralateral subthalamic nucleus, caudate nucleus, putamen, and thalamus. One model of basal ganglia function suggests that reduced basal ganglia output to the thalamus disinhibits thalamic relay nuclei leading to increased excitability in thalamocortical pathways which passes to descending motor pathways resulting in involuntary movements.

Recognized causes of chorea and choreoathetosis are many, including:

• Hereditary:
  • Huntington’s disease (HD)
  • Dentatorubropallidoluysian atrophy (DRPLA)
  • Neuroacanthocytosis
  • Benign hereditary chorea

Paroxysmal dyskinesias: paroxysmal kinesigenic choreoathetosis (PKC) and paroxysmal dystonic choreoathetosis (PDC)

• Sporadic:
  • Drugs: levodopa therapy in later stages of idiopathic Parkinson’s disease
  • Pregnancy: chorea gravidarum
  • Hyperthyroidism
  • Systemic lupus erythematosus (SLE)
    Sydenham’s chorea (post-infectious, rheumatic chorea, St. Vitus dance, PANDAS)
  • Polycythemia rubra vera (hyperviscosity)
  • AIDS
  • Hyperosmolality (hyperglycemia, hypernatremia) CNS tumor
  • Multiple sclerosis (rare)
  • Variant Creutzfeldt-Jakob disease
  • "Senile chorea" (diagnosis of exclusion, especially of HD)

Where treatment is necessary, antidopaminergic agents, such as dopamine receptor antagonists (e.g., neuroleptics, sulpiride, risperidone) and dopamine depleting agents (e.g., tetrabenazine, reserpine) may help, although they may cause parkinsonism, akathisia, neuroleptic malignant syndrome, and sedation. Chronic neuroleptic use may also cause chorea, but these movements are repetitive and predictable, unlike "classic" chorea.

 

References

Barker R. Chorea: diagnosis and management. Advances in Clinical Neuroscience & Rehabilitation 2003; 3(4): 19-20
Sawle G. Chorea. In: Sawle G (ed.). Movement disorders in clinicalpractice. Oxford: Isis Medical Media, 1999: 119-133
Schrag A, Quinn N. Huntington’s disease and other choreas. Journal ofNeurology 1998; 245: 709-716

 

Cross References

Athetosis; Ballism, Ballismus; Dyskinesia; Hypotonia, Hypotonus; Milkmaid’s grip; Pseudochoreoathetosis; Rigidity; Trombone tongue