Clinical differences in patients with Parkinson's disease according to tandem gait performance

Longitudinal prediction of falls and near falls frequencies in Parkinson's disease: a prospective cohort study

Introduction and objective

Several prediction models for falls/near falls in Parkinson’s disease (PD) have been proposed. However, longitudinal predictors of frequency of falls/near falls are poorly investigated. Therefore, we aimed to identify short- and long-term predictors of the number of falls/near falls in PD.

Methods

A prospective cohort of 58 persons with PD was assessed at baseline (mean age and PD duration, 65 and 3.2 years, respectively) and 3.5 years later. Potential predictors were history of falls and near falls, comfortable gait speed, freezing of gate, dyskinesia, retropulsion, tandem gait (TG), pain, and cognition (Mini-Mental State Exam, MMSE). After each assessment, the participants registered a number of falls/near falls during the following 6 months. Multivariate Poisson regression was used to identify short- and long-term predictors of a number of falls/near falls.

Results

Baseline median (q1–q3) motor (UPDRS) and MMSE scores were 10 (6.75–14) and 28.5 (27–29), respectively. History of falls was the only significant short-time predictor [incidence rate ratio (IRR), 15.17] for the number of falls/near falls during 6 months following baseline. Abnormal TG (IRR, 3.77) and lower MMSE scores (IRR, 1.17) were short-term predictors 3.5 years later. Abnormal TG (IRR, 7.79) and lower MMSE scores (IRR, 1.49) at baseline were long-term predictors of the number of falls/near falls 3.5 years later.

Conclusion

Abnormal TG and MMSE scores predict the number of falls/near falls in short and long term, and may be indicative of disease progression. Our observations provide important additions to the evidence base for clinical fall prediction in PD.

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

INTRODUCTION

Tandem 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.

METHODS

Subjects (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).

RESULTS

Compared 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.

CONCLUSIONS

Tandem 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.