[Chorea: general aspect and classification].
Chorea is a hyperkinetic involuntary movement disorder characterized by a random pattern of irregular muscle jerks. This movement may involve any parts of the body. Emotional stress or voluntary movements may exacervate chorea and sleep abolish it. Luys body and striatum are the most important anatomical sites to evoke chorea. The lesion of inner segment of pallidum or ventrolateral thalamus may abolish chorea. Measurements of neurotransmitter changes of Huntington's disease show diminution of striatal GABA neurons and preserving nigrostriatal dopamine neurons. Dopamine antagonists can reduce chorea because doperminergic hyperactivity contribute to exacervate chorea. Precise pathophysiological mechanism of chorea is controversial, therefore its classification is not established. On the clinical point of view, classification according to heredity is useful to make diagnosis because hereditary diseases are easily confirmed by family history or specific biochemical markers. There are two groups of underlying diseases of non hereditary chorea. One is unilateral chorea usually due to contralateral hemispheric lesions to chorea. Another is bilateral chorea usually due to degenerative, metabolic or toxic brain diseases. Recent identification of abnormal DNA structure (trinucleotide repeat) in Huntington's disease may greatly contribute to classify underlying diseases of chorea.
Nagura
H
H
Department of Neurology, Tokyo Metropolitan Geriatric Hospital.
D000328:Adult; D002819:Chorea / Q000145:classification / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged