A childhood form of Huntington's disease associated with marked pyramidal signs.

The case of a childhood form of Huntington's disease in a 9-year-old boy is reported. The patient had complaints of generalized convulsions from the age of 4, and progressive motor disabilities and mental deterioration from the age of 6. His father had suffered from Huntington's disease for 10 years, and his paternal uncle and aunt, who died at the age of 52, were diagnosed as having this disease. Neurological examination revealed severe mental retardation and marked pyramidal signs. He has no signs or symptoms of involuntary movement, muscular rigidity or ataxia. Axial computed tomography showed marked dilatation of the frontal horns and suggested caudate atrophy. This case is atypical of a childhood form of Huntington's disease because of the lack of muscular rigidity and choreiform movement. But computed tomographic findings correspond to that typically seen in cases of adult Huntington's disease.