Differential diagnosis of parkinsonism with visual inspection of posture and gait in the early stage

•Differential diagnosis of parkinsonism is difficult in early stage.•We analyzed a structured visual inspection of gait and posture patterns.•Asymmetric arm-swing and accompanied tremor are suggestive of PD.•Staggering and en-bloc turning are suggestive atypical parkinsonism.•These analyses provide clues for differential diagnosis of parkinsonism.

BackgroundParkinson's disease (PD) differs from atypical parkinsonism in many clinical aspects. Principally, posture and gait are distinct features in the early stages of the disease; thus, these differences can be helpful in differential diagnosis.MethodsWe analyzed videos of patients with PD or atypical parkinsonism. A total of 76 patients with early PD (n = 56) or atypical parkinsonism (n = 20) were included. Items related to posture and gait were classified into three categories (standing, gait and associated symptoms) and each sub-item was analyzed.ResultsAsymmetric arm-swing (p = 0.004) and accompanying tremor (p = 0.016) were significant indicators of early-stage PD. Staggering gait (p = 0.007) and en-bloc turning (p = 0.026) were more common in atypical parkinsonism. Characteristics with a high odds-ratio for atypical parkinsonism were en-bloc turning (β = 8.475, p = 0.032) and normal arm-swing (β = 14.6084, p = 0.036).ConclusionsVisual inspection of gait and posture provides reliable clues in the differential diagnosis of parkinsonism.