Local cerebral glucose utilization in symptomatic and presymptomatic Huntington's disease.

Patterns of local cerebral glucose utilization were measured with positron emission CT using the 18F-fluorodeoxyglucose method in 13 patients with HD, 15 subjects at risk for HD, and control subjects. These data were compared with CT measures of cerebral atrophy, age, and duration and severity of symptoms. The results indicate that in HD there is a characteristic decrease in glucose utilization in the caudate and putamen and that this local hypometabolism appears early and precedes bulk tissue loss. In contrast to demented patients with Alzheimer's disease or Parkinson's disease, in these HD patients glucose utilization typically was normal throughout the rest of the brain, regardless of the severity of symptoms and despite apparent shrinkage of brain tissue. Our results indicate that the caudate is hypometabolic in some asymptomatic persons who are carriers of the autosomal-dominant gene for HD.