REGIONAL CHANGES IN [F-18] DOPA METABOLISM IN THE STRIATUM IN PARKINSONS-DISEASE

We have investigated regional changes in dopamine metabolism within th e basal ganglia with clinical progression of idiopathic Parkinson's di sease, using coregistration of [F-18]dopa-PET and MRI images and compa ring six normal subjects with 15 Parkinson's disease patients in a cro ss-sectional study. We have demonstrated that [F-18]dopa metabolism in the dorsal putamen is reduced to almost 50% of normal both caudally a nd rostrally early in the disease whilst the ventral putamen is not si gnificantly affected. With progression of symptoms there is loss of do pa metabolism from the ventral putamen, the ventrocaudal putamen in ad vance of the ventrorostral putamen. Throughout the disease the ventror ostral putamen is relatively presented; even in the most advanced grou p [F-18]dopa uptake is reduced here by only 30%. We conclude that the progression of Parkinson's disease is associated with a focal process affecting only the dorsal putamen in its early (and preclinical) phase then affecting the ventral putamen with increasing disease severity.