Comparison of gait in progressive supranuclear palsy, Parkinson's disease and healthy older adults

Background: Progressive supranuclear palsy and Parkinson's disease have characteristic clinical and neuropathologic profiles, but also share overlapping clinical features. This study aimed to analyze the gait of people with progressive supranuclear palsy (n=19) and compare it with people with Parkinson's disease (n=20) and healthy older adults (n=20). Methods: Gait was recorded at self-selected preferred, fast, very fast, slow and very slow speeds. Stride length was normalized to leg length. Linear regression analyses were carried out between cadence and stride length. Other gait variables were compared for each participant's 'walk' which had stride length closest to 1.4. Results: All groups showed a strong linear relationship between stride length and cadence with no difference between groups (p>0.05). The intercept between cadence and stride length was lowest in the progressive supranuclear palsy group and highest for older adults (p<0.001). The progressive supranuclear palsy group had higher cadence than older adults (p>0.05), and greater step width and greater double support phase compared with the other two groups (p<0.05). Conclusions: The temporal-spatial gait characteristics of progressive supranuclear palsy and Parkinson's disease are largely similar, with similar disruption to scaling of stride length. The additional findings of increased step width and double support percentage suggest increased severity of gait abnormality compared to Parkinson's disease, despite similar disease duration. The findings are consistent with the clinical features of greater instability and more rapid disease progression in progressive supranuclear palsy compared to Parkinson's disease and implicates the early pathological involvement of brain regions involved in gait control.