Contributions of mild parkinsonian signs to gait performance in the elderly

Mild parkinsonian signs (MPS) and gait abnormalities are common in aging, but the association between MPS and objective gait measures is not established in the elderly. This study aims to identify the link between MPS and quantitative gait measures, as well as to determine the pathogenesis of MPS in non-demented community-dwelling older adults without idiopathic Parkinson's disease or other parkinsonian syndromes. Three hundred seventy-four non-demented older adults (mean age, 76.44±6.71 years, 57% women) participated in this study, where comprehensive neurological and medical assessments were conducted. We defined MPS based on the presence of any one of bradykinesia, rigidity, or rest tremor. Velocity and spatial, temporal, and variability gait parameters were recorded using an instrumented walkway. The associations of MPS and gait parameters as well as the relationship of individual MPS with medical illnesses were assessed with linear regressions controlling for key covariates. Participants with MPS walked slower and with disturbed spatial and variability components of gait compared to those without MPS. Bradykinesia was associated with worse spatial and variability gait parameters. This association was only significant for axial bradykinesia, but not for the presence of bradykinesia in the limbs. Cerebrovascular disease (β=.20, p<.01) was associated with bradykinesia, whereas cardiovascular disease (β=.15, p<.05) was associated with rigidity. Among MPS, bradykinesia but not rigidity or tremor was associated with worse quantitative gait performance in older adults. Cerebrovascular disease, a preventable condition, was specifically associated with bradykinesia.