Reduction in presynaptic dopamine transporter may be associated with future problematic delusion

Area of Science:

• Neuroscience
• Neurology
• Radiology

Background:

• Psychosis, particularly delusions, significantly diminishes the quality of life for Parkinson's disease (PD) patients and their caregivers.
• Objective indicators for predicting psychosis in PD are limited, and the role of dopamine transporter (DAT) binding remains unclear.
• Long-term prognostic data on DAT binding for predicting delusions in PD are lacking.

Purpose of the Study:

• To investigate whether baseline dopamine transporter (DAT) binding, measured by [123I]FP-CIT SPECT, serves as a prognostic risk factor for the future development of delusions in Parkinson's disease (PD).
• To assess the association between striatal DAT binding and the occurrence of delusions within a 5-year follow-up period.

Main Methods:

• Retrospective chart review of 61 Parkinson's disease (PD) patients without prior psychosis who underwent [123I]FP-CIT SPECT.
• Delusions occurring within 5 years post-SPECT were defined as the study endpoint.
• Specific binding ratio (SBR) values in the striatum were calculated and compared between patients who developed delusions and those who did not, with adjustments for confounding factors.

Main Results:

• Eleven out of 61 PD patients developed delusions within 5 years of [123I]FP-CIT SPECT.
• Significantly lower average, minimum, maximum, right-sided, and left-sided striatal SBRs were observed in patients who developed delusions compared to those who did not (p < 0.004 for all).
• These differences remained significant after controlling for age, gender, disease severity, medication, and other clinical factors.

Conclusions:

• Reduced dopamine transporter (DAT) binding in the striatum is a significant predictor of future delusion development in Parkinson's disease (PD) patients.
• Striatal DAT binding, assessed via [123I]FP-CIT SPECT, can serve as an objective prognostic marker for psychosis in PD.
• Lowering DAT binding may be a valuable indicator for predicting future delusions, irrespective of the timing of the SPECT scan.