A. Antonini et al., COMPLEMENTARY PET STUDIES OF STRIATAL NEURONAL FUNCTION IN THE DIFFERENTIAL-DIAGNOSIS BETWEEN MULTIPLE SYSTEM ATROPHY AND PARKINSONS-DISEASE, Brain, 120, 1997, pp. 2187-2195
We used PET with the tracers [F-18]fluorodeoxyglucose (FDG), [F-18]flu
orodopa (FDOPA) and [C-11]raclopride (RACLO) to study striatal glucose
and dopa metabolism, and dopamine D-2 receptor binding, respectively,
in nine patients with multiple system atrophy. Ten patients with clas
sical Parkinson's disease were investigated with the same three PET tr
acers' and three separate groups, each of 10 healthy subjects, sewed a
s control populations. We found that striatal FDOPA values separated a
ll healthy subjects from patients with parkinsonism but they were not
useful in distinguishing multiple system atrophy from Parkinson's dise
ase. Conversely, striatal RACLO as well as FDG values discriminated al
l multiple system atrophy from Parkinson's disease patients as well as
from healthy control subjects. Metabolic and receptor binding decreme
nts in the putamen of multiple system atrophy patients were significan
tly correlated Stepwise regression analysis revealed that a linear com
bination of putamen RACLO and FDOPA values accurately predicted clinic
al measures of disease severity in the multiple system atrophy group.
Our findings suggest that striatal FDG and particularly RACLO are sens
itive and effective measures of striatal function and may help charact
erizing patients with multiple system atrophy. In contrast FDOPA measu
rements are accurate in detecting abnormalities of the nigrostriatal d
opaminergic system but may not distinguish among different forms of pa
rkinsonism.