Dopamine transporter imaging under high-dose transdermal nicotine therapy in Parkinson's disease: an observational study.
OBJECTIVE
Nicotine therapy might improve the course of Parkinson's disease. This observational study evaluated the performance of dopamine transporter imaging in follow-up patients under nicotine therapy.


METHODS
Six Hoehn and Yahr stage III patients underwent 123I-FP-CIT imaging prior to, 3 months, and 1 year after the onset of nicotine therapy. Nicotine was administered transdermally with increasing daily doses during 3 months (up to 105 mg/day) and decreased progressively. On co-registered magnetic resonance imaging, striatal regions of interest were drawn and binding potentials of 123I-FP-CIT were calculated.Changes in Unified Parkinson's Disease Rating Scale-III over time were compared with binding potentials using regression analysis.


RESULTS
All patients improved motor scores at 3 months (-65 +/- 22% 'off', -89 +/- 12% 'on') and most received fewer dopaminergic drugs (-30% dosage in average). Motor improvement persisted to a lesser extent at 1 year(-39 +/- 31% 'off', -13 +/- 43% 'on'), partly because one patient stopped the treatment. Interestingly, the decrease in binding potentials (-4.0 +/- 10.5%) was slower than that expected in Parkinsonian patients (usually -10% per year) and was inversely correlated with Unified Parkinson's Disease Rating Scale-III improvement, r= 0.83 'off' and 0.91 'on'.


CONCLUSIONS
This observational study emphasizes a potential effect of nicotine therapy on striatal dopamine transporter density, which may be interpreted as direct pharmacological effect or deceleration of neuronal loss.
Itti
Emmanuel
E
Department of Nuclear Medicine, H. Mondor Hospital, AP-HP, Paris 12 University, Créteil, France. emmanuel.itti@hmn.aphp.fr
Villafane
Gabriel
G
Malek
Zoulikha
Z
Brugières
Pierre
P
Capacchione
Daniela
D
Itti
Laurent
L
Maison
Patrick
P
Cesaro
Pierre
P
Meignan
Michel
M
D000279:Administration, Cutaneous; D050483:Dopamine Plasma Membrane Transport Proteins / Q000032:analysis / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D017072:Neostriatum / Q000187:drug effects / Q000503:physiopathology; D009538:Nicotine / Q000008:administration & dosage* / Q000627:therapeutic use*; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000378:metabolism*; D012044:Regression Analysis; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon; D014326:Tropanes
D050483:Dopamine Plasma Membrane Transport Proteins; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane; D009538:Nicotine