Absent STS Is Accurate for Patients With Uncertain PD

Background: Up to 30% of patients with movement disorder, cannot be classified upon presentation and are put into a clinically uncertain Parkinsonian syndrome category. The delay in diagnosis can affect ability to receive early treatment of the disease. Objective: To compare the finding of an absent swallow tail sign (STS) on 3T MRI and iodine 123–2β-carbomethoxy-3β-(4-iodophenyl)- N -(3-fluoropropyl)-nortropan ( 123 I-FP-CIT) SPECT (DaTscan) in diagnosing patients with uncertain parkinsonian syndrome. Design: Prospective, multicenter study. Participants: 106 patients with uncertain Parkinsonian syndrome scanned at 2 sites on 3T MRI scanners with susceptibility-weighted MRI sequence to evaluate for the presence or absence of a swallow tail sign. Methods: All patient underwent 123 I-FP-CIT SPECT. Results were anonymized and read by 2 readers, with discrepancies going to a third reader for review. Patients were followed clinically for 2 years. Results: Of 106 patients, more...