[An autopsy case of late-onset chorea].

Senile chorea has been an ill-defined clinical entity because of the difficulty of differentiating it from Huntington's disease (HD) of late-onset type. The gene specific for HD has recently been found to contain an abnormal (CAG)n trinucleotide repeat which allows it to be differentiated from the other conditions. Our case of late-onset chorea was differentiated from HD by PCR. An 80-year-old man had experienced gradually increasing chorea of his tongue, arms and legs for 4 years, but had not exhibited character changes, mental symptoms or dementia. He died of pneumonia at 84 years. The pathological findings in this case were different from those of HD. The brain weighted 1220 g, and did not show striatal atrophy or neuronal loss. The most remarkable findings were numerous foamy spheroids scattered in the caudate and putamen and proliferation of fibrous astrocytes within the thin myelinated fiber bundles and in the neuropil. Similar findings were reported by Freidman et al. (1990). Although it is debatable whether this finding was responsible for the development of the chorea, this case should contribute to our understanding of senile chorea as a clinicopathological entity.