Dopamine Transporter Imaging has no Impact on Functional Outcomes in de Novo Probable Parkinson's Disease

Parkinson's disease (PD) is among the most prevalent neurodegenerative conditions. While motor and non-motor aspects of this disease have been well characterized, no objective biomarker exists to support an accurate clinical diagnosis. However, newer imaging techniques, including [123I]-FP-CIT (DaTSCAN), have demonstrated utility in differentiating between PD and non-neurodegenerative tremor disorders.

DaTSCAN has been primarily investigated in situations where diagnostic confusion exists, and in these instances has been shown to significantly impact clinical management. The goal of this pilot study was to evaluate the impact of DaTSCAN on the clinical management of patients with early probable PD, where no diagnostic uncertainty exists.

This was a prospective, 54-week, comparative pilot study, in which twenty subjects with de novo PD were randomly assigned to DaTSCAN either immediately upon diagnosis (and again at 6 and 12 months) or delayed to 6 months (and again at 12 months). The primary outcome measure was the frequency of deviation from the initial treatment plan from baseline to 54 weeks between the two groups. Secondary outcomes included motor and non-motor assessments.

There was no significant difference in the number of treatment changes over the course of the study between the two groups: initial imaging group = 4.2 (SD:2.74) vs. delayed imaging group = 2.3 (SD:2.0, p = 0.11). In addition, there were no group differences in medication requirements, motor performance, or patient expectations of disease.

In patients with early, probable PD, DaTSCAN contributes no additional impact on clinical management or functional outcomes when added to the diagnostic algorithm.