Objective impairment of tandem gait in Parkinson's disease patients increases with disease severity

Abstract

IntroductionTandem gait abnormalities have been reported to increase with advancing age, play a role in fall-prediction in Parkinson's disease, and distinguish it from atypical parkinsonism. Tandem gait has been scored based on the number of side steps off a straight line in these studies. Objective measurement of spatiotemporal tandem gait parameters in Parkinson's disease has not been previously reported. MethodsSubjects (74 Parkinson's disease and 28 controls) were enrolled after IRB approval. Those with more than 1 fall/day or a Montreal Cognitive Assessment score <10 were excluded. Subjects tandem walked (“heel to toe”) on a 20 foot pressure-sensor mat. Data was collected and analyzed using PKMAS software (Protokinetics). ResultsCompared to controls, on tandem gait, Parkinson's subjects had increased step width, stride width and path width, with a slower stride velocity and an increased time spent in all phases of the gait cycle. Parkinson's subjects also applied greater pressure with each step and had greater step-to-step variability in tandem gait measures. While Hoehn & Yahr stage 1 subjects were not significantly different from controls, stage 2 and 2.5 + groups were different. Parkinson's subjects with freezing of gait also walked with a wider base compared to those without gait freezing. Tandem gait spatiotemporal parameters were not correlated with fall frequency. ConclusionsTandem gait is impaired in Parkinson's disease in a stage-dependent manner, with wider base and increased step-to-step variability, which could suggest involvement of cerebellar and mediolateral balance pathways.