Impact of DaTscan on the Management of Clinically Uncertain Parkinsonian Syndromes: A Retrospective Canadian Cohort Study

ABSTRACT Background: Diagnosing clinically uncertain parkinsonian syndromes (CUPS) is challenging. Dopamine transporter (DaT) SPECT imaging (DaTscan) aids in differentiation, but its real-world impact on management in Canada, where it is not publicly funded, is unclear. The objective was to determine the impact of DaTscan results on clinical management for patients with CUPS in a Canadian tertiary care movement disorder service. Methods: We conducted a retrospective chart review of 42 patients with CUPS referred for a DaTscan from a tertiary clinic in London, Ontario. DaTscan result was categorized as “Abnormal” (positive scan) or “Normal” (negative scan). The primary outcome was a change in management (Present/Absent). The association was assessed using Fisher’s Exact test. Results: Forty-two patients were included (median age 63 years; 50% female). Twenty-seven scans (64%) were abnormal, and 15 (36%) were normal. Overall, clinical management was changed in 13 patients (31%; 95% CI: 18% to 47%). A change in management was significantly more likely after a normal scan (60%, 9/15 patients) compared to an abnormal scan (15%, 4/27 patients) ( p = 0.009). Changes after a normal scan primarily involved discontinuing dopaminergic therapy (7/9, 78%). Conclusions: In this specialized clinic, DaTscan results informed management in 31% of CUPS patients. A normal scan provides the objective evidence needed to withdraw unnecessary dopaminergic medications confidently.