Parkinson's disease subtypes show a specific link between dopaminergic and glucose metabolism in the striatum.
BACKGROUND
Previous studies have shown different clinical and imaging pattern in tremordominant and akinetic-rigid Parkinson's disease (PD) subtypes. The association between dopaminergic and glucose metabolism has in contrast not been investigated yet. Therefore, this study compared PD subtypes with respect to clinical and imaging findings with the aim of establishing a relationship between clinical subtypes, dopamine and glucose metabolism.


METHODS
Two groups of a total of 64 idiopathic PD patients (42 male, 22 female, mean age 56 ± 10.9 years) were analysed: akinetic-rigid (AR, n = 32) and tremor-dominant (TD, n = 32) patients. Both were compared with respect to differential involvement of local striatal dopamine and glucose metabolism using [18F]-fluoro-L-dopa (F-dopa) and [18F]-fluorodeoxyglucose (FDG)-PET.


RESULTS
The analysis of PD subgroups showed significant differences in the F-dopa uptake in the anterior putamen. Using the results of the local striatal dopamine difference as a volume of interest for the FDG-analysis, analysis of AR patients revealed a significantly lower normalised cerebral metabolic rate of glucose (nCMRGlc) within the ventral striatum.


CONCLUSIONS
The dual tracer study illlustrates clear differences between TD and AR subtypes in the ventral striatum. In accordance with previous FP-CIT-SPECT studies, it discloses congruent results for the presynaptic dopaminergic system and extends the knowledge about an additional involvement of local metabolic activity in the caudate and anterior putamen. The findings corroborate the specific role of distinct PD subtypes within the cerebello-thalamo-cortical-circuits. Multitracer PET imaging may thus enhance the knowledge about the clinical segregation into subtypes.
Department of Neurology, University Hospital of Cologne, Cologne, Germany.
Carsten
C
Eggers
Department of Neurology, University Hospital of Cologne, Cologne, Germany.
Frank
F
Schwartz
Department of Neurology, University Hospital of Cologne, Cologne, Germany.
David J
DJ
Pedrosa
Max-Planck-Institute for Neurological Research, Cologne, Germany.
Lutz
L
Kracht
Department of Neurology, University Hospital of Cologne, Cologne, Germany.
Lars
L
Timmermann
D000368:Aged; D004295:Dihydroxyphenylalanine / Q000031:analogs & derivatives / Q000493:pharmacokinetics; D004298:Dopamine / Q000378:metabolism*; D059290:Dopaminergic Neurons / Q000378:metabolism; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012189:Retrospective Studies; D066328:Ventral Striatum / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; C043437:fluorodopa F 18; D004295:Dihydroxyphenylalanine; D005947:Glucose; D004298:Dopamine