Degenerative parkinsonism in patients with psychogenic parkinsonism: A dopamine transporter imaging study.

Objectives: To evaluate patients with "clinically established" psychogenic parkinsonism (PsyP) using single-photon emission computer tomography (SPECT) with the technetium-99m labeled tracer TRODAT-1, a dopamine transporter (DAT) ligand, and investigate whether these patients have an underlying degenerative parkinsonism.
Patients and Methods: Five patients with PsyP were assessed using demographic data, standard clinical scales for Parkinson's Disease (PD), and a neuropsychiatric interview. DAT imaging using SPECT with TRODAT-1 was performed, and values for caudate/putamen DAT binding potentials (BP) registered. Patients with PsyP were matched with PD (n=5) and healthy control subjects (n=5).
Results: The mean age (years-old) at first evaluation in the PsyP group was 37.4+/-3.7, and the mean disease duration (years) was 3.9+/-1.2. DAT BPs (means+/-standard deviations) on right/left caudate were, respectively, 0.69+/-0.18 and 0.70+/-0.18 in the PD group versus 1.17+/-0.06 and 1.12+/-0.10 in the control group. DAT BPs on right/left putamen were, respectively, 0.48+/-0.10 and 0.45+/-0.06 in the PD group versus 1.10+/-0.10 and 1.21+/-0.43 in the control group. Two out of five patients from the PsyP group had values for DAT BP in the putamen under the cut-off (< or =0.70) for controls, implying pre-synaptic dopaminergic deficit.
Conclusions: Our data in this small group of patients suggest that DAT imaging is a tool that may help in the identification of underlying degenerative parkinsonism in PsyP.
(Copyright 2009 Elsevier B.V. All rights reserved.)