Abstract:
OBJECTIVE--To determine the rate of change of glucose metabolism
and caudate size in persons at risk for Huntington's disease. DESIGN--
Eighteen persons at risk for Huntington's disease had two positron
emission tomographic glucose metabolic studies and two magnetic
resonance imaging scans separated by 42 (+/- 9) months. SETTING--
Ambulatory research subjects at a teaching hospital with magnetic
resonance imaging and positron emission tomographic technology.
SUBJECTS--Seven of the individuals were Huntington' disease gene
negative by testing at the polymorphic DNA loci D4S10, D4S43, and
D4S125; the remainder were gene positive by genetic testing or onset of
chorea after study entry. INTERVENTIONS--None. OUTCOME MEASURES--Onset
of chorea and imaging results. RESULTS--The gene-positive group
demonstrated a significant 3.1% loss of glucose metabolic rate per year
in the caudate nucleus (95% confidence interval [CI], -4.64, -1.48)
compared with the gene-negative group. There was a 3.6% per year
increase in the magnetic resonance imaging bicaudate ratio (95% CI,
1.81, 5.37), a linear measure of caudate atrophy. The rate of change in
caudate size did not correlate with the rate of change in caudate
metabolism, suggesting that metabolic loss and atrophy may develop
independently. CONCLUSIONS--The results suggest that a reduction in
caudate glucose metabolism and atrophy develop rapidly in Huntington's
disease. The findings establish a strategy for using serial positron
emission tomographic imaging to monitor experimental pharmacologic
interventions in presymptomatic individuals who have developed caudate
hypometabolism