Dopamine transporter imaging and the effects of deep brain stimulation in patients with Parkinson's disease.
OBJECTIVE
Single-photon emission computed tomography (SPECT) with [123I]FP-CIT is a marker for loss of presynaptic dopamine transporters in the striatum in Parkinson's disease (PD). We used [123I]FP-CIT SPECT in order to evaluate binding to the dopamine transporter before and after neurosurgical treatment with bilateral stimulation in the subthalamic nucleus (STN).


METHODS
Thirty-five patients with levodopa-responsive PD were examined with [123I]FP-CIT SPECT pre-operatively (baseline scan: mean 3 months before surgery), and 3 and 12 months after surgery.


RESULTS
Pre-operatively, all patients already had substantial signs of severe nigrostriatal neuronal loss as determined from the [123I]FP-CIT SPECT scans. One year after surgery the specific [123I]FP-CIT binding to the striatum was significantly reduced by 10.3% compared with the pre-operative baseline scan. The mean time span from the baseline scan before surgery to the follow-up scan 1 year after surgery was 16.2 months. Hence, the rate of reduction equals a mean annual reduction of 7.7%. A comparable control group of patients with PD who did not undergo surgery was also examined longitudinally. In this group the specific binding of [123I]FP-CIT was reduced by 6.7% per year.


CONCLUSIONS
The specific binding of [123I]FP-CIT was reduced equally in the STN-stimulated patients and a group of non-operated PD patients with advanced disease. Our study does not support the notion that electrode implantation and STN stimulation exert a neuroprotective effect by themselves.
Lokkegaard
A
A
Department of Clinical Physiology and Nuclear Medicine, Bispebjerg University Hospital, Copenhagen, Denmark. alokkegaard@dadlnet.dk
Werdelin
L M
LM
Regeur
L
L
Karlsborg
M
M
Jensen
S R
SR
Brødsgaard
E
E
Madsen
F F
FF
Lonsdale
M N
MN
Friberg
L
L
D000328:Adult; D000368:Aged; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism*; D046690:Deep Brain Stimulation; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000628:therapy*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D016896:Treatment Outcome; D014326:Tropanes / Q000493:pharmacokinetics*
D050483:Dopamine Plasma Membrane Transport Proteins; D019275:Radiopharmaceuticals; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane