Striatal dopamine transporter imaging correlates with anxiety and depression symptoms in Parkinson's disease.
We studied the correlation of striatal dopamine transporter (DAT) imaging with anxiety and depression symptoms in Parkinson's disease (PD).


METHODS
Patients with idiopathic PD (n = 76) and age-matched healthy volunteers (n = 46) underwent SPECT brain scans with (99m)Tc-TRODAT-1, a radiolabeled tropane that selectively binds to the DAT. TRODAT-1 distribution volume ratios, a reflection of DAT availability, were calculated from the SPECT scan data for 6 regions of interest (ROIs) in the caudate and putamen. The association between neuropsychiatric symptoms (anxiety, depression, and fatigue) and DAT availability was explored for both subject groups, and the impact of disease severity on this association was examined in the PD group.


RESULTS
PD patients showed lower DAT availability than did healthy volunteers in all examined regions (for all ROIs, P < 0.001). In PD patients, higher individual affective measures (for anxiety, r = -0.30 and P = 0.01; and for depression, r = -0.24 and P = 0.05) and total affect scores (r = -0.31; P = 0.01) were associated with diminished left anterior putamen DAT availability. The association between total affect scores and DAT availability was present only in the subset of patients with less severe PD (r = -0.35; P = 0.04), but subjects with the highest DAT availability did not show high total affect scores. No association between neuropsychiatric measures and DAT availability was found in the controls.


CONCLUSIONS
These preliminary findings suggest that decreased DAT availability may be necessary for but not invariably associated with the development of affective symptoms in PD. This suggestion is consistent with previous research showing a link between depression and basal ganglia impairment, particularly involving the left hemisphere, and extends this finding to include anxiety.
Weintraub
Daniel
D
Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA. weintrau@mail.med.upenn.edu
Newberg
Andrew B
AB
Cary
Mark S
MS
Siderowf
Andrew D
AD
Moberg
Paul J
PJ
Kleiner-Fisman
Galit
G
Duda
John E
JE
Stern
Matthew B
MB
Mozley
David
D
Katz
Ira R
IR
D001007:Anxiety / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000209:etiology / Q000378:metabolism*; D015415:Biomarkers; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism*; D003863:Depression / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000209:etiology / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins; D005260:Female; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000378:metabolism*; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics*; D010300:Parkinson Disease / Q000150:complications / Q000000981:diagnostic imaging / Q000378:metabolism*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013223:Statistics as Topic; D014018:Tissue Distribution; D014326:Tropanes / Q000493:pharmacokinetics*
D015415:Biomarkers; D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C493214:SLC6A3 protein, human; D014326:Tropanes; C104196:technetium Tc 99m TRODAT-1