Chronic subthalamic nucleus stimulation and striatal D2 dopamine receptors in Parkinson's disease--A [(11)C]-raclopride PET study.
BACKGROUND
Subthalamic nucleus (STN) stimulation mechanism of action remains a matter for debate. In animals, an increased striatal dopamine (DA) release due to STN stimulation has been reported.


OBJECTIVE
To determine in Parkinson's disease (PD) patients using positron emission tomography (PET) and [11C]-Raclopride, whether STN stimulation induces a striatal DA release.


METHODS
Nine PD patients with bilateral STN stimulation were enrolled and underwent two [11C]-Raclopride PET scans. The scans were randomly performed in off and on stimulation conditions. Striatal [11C]-Raclopride binding potential (BP) was calculated using regions of interest and statistical parametric mapping.


RESULTS
For PD patients, the mean [(11C]-Raclopride BP (+/- SD) were, in Off stimulation condition: 1.7 +/- 0.3 for the right caudate nucleus, 1.8 +/- 0.4 for the left caudate nucleus, 2.6 +/- 0.5 for the right putamenand 2.6 +/- 0.5 for the left putamen. In On stimulation condition: 1.7 +/- 0.4 for the right caudate nucleus, 1.9 +/- 0.5 for the left caudate nucleus, 2.8 +/- 0.7 for the right putamen and 2.7 +/- 0.8 for the left putamen. No significant difference of BP related to the stimulation was noted.


CONCLUSIONS
STN stimulation does not produce significant variations of striatal DA release as assessed by PET and [11C]-Raclopride.
Dept. of Neurology D (Pr. G. Chazot) and INSERM U 534, Hôpital Neurologique Pierre Wertheimer, 59 Bd Pinel, 69003 Lyon, France. stephane.thobois@chu-lyon.fr
S
S
Thobois
V
V
Fraix
M
M
Savasta
N
N
Costes
P
P
Pollak
P
P
Mertens
A
A
Koudsie
D
D
Le Bars
A L
AL
Benabid
E
E
Broussolle
D000328:Adult; D000368:Aged; D002250:Carbon Radioisotopes; D004298:Dopamine / Q000378:metabolism*; D018492:Dopamine Antagonists; D004599:Electric Stimulation Therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000628:therapy*; D020891:Raclopride; D017448:Receptors, Dopamine D2 / Q000502:physiology*; D020531:Subthalamic Nucleus / Q000502:physiology*; D014055:Tomography, Emission-Computed
D002250:Carbon Radioisotopes; D018492:Dopamine Antagonists; D017448:Receptors, Dopamine D2; D020891:Raclopride; D004298:Dopamine