STRIATAL DOPAMINE D-2 RECEPTORS IN PATIENTS WITH NARCOLEPSY MEASURED WITH PET AND C-11 RACLOPRIDE

We investigated in vivo D-2 receptor binding using C-11-raclopride and PET in the striatum of 17 subjects with the narcoleptic syndrome. Putamen and caudate nucleus C-11-raclopride uptake was comparable in the total patient group and controls, and the tracer uptake was similar in the HLA-DR2-positive (n = 12) and HLA-DR2-negative (n = 5) narcoleptic subjects. There was a significant increase in C-11-raclopride uptake in the putamen of narcoleptic subjects older than 31 years (n = 11) when compared with age-matched controls (n = 15). There was no evidence of involvement of the striatal D-2 dopaminergic neurotransmitter system in the basic pathophysiology of the narcoleptic syndrome despite an age-related increase in putaminal C-11-raclopride uptake.