[Myoclonic type of Huntington's chorea (author's transl)].

The authors report the case of an 8 year-old boy who, when he was 2 1/2 years old, suffered from spasmodic mouth twitches. At the age of four, various other symptoms appeared: psychomotor backwardness, frequent fails and a photomyoclonic response on electroencephalogram. At the age of 5 1/2, noticeable difficulties appeared in walking with a broad-based gait, hypotonia, and intentional trembling associated with hypokinesia and dysarthria. When he was six, the first convulsive seizure appeared, then myoclonies which became continuous. The child gradually became bedridden. The family history tends to show these disorders can be linked with a Huntington chorea affecting six generations. This case is very similar to that previously described by the authors, in an 8 year-old girl where an anatomic examination revealed the existence of lesions characteristic of Huntington's disease associated with lesions of the cerebellum. The authors, on the basis of the data provided by the literature, discuss the myoclonic and cerebellous aspect of this infantile form. Lacking anatomic evidence, they stress the interest of the biochemical disturbances affecting the cerebral monoamines noted in this observation.