Assessment of dual tasking has no clinical value for fall prediction in Parkinson’s disease

Katrijn Smulders,Rianne A J Esselink,Alexander C H Geurts,Aner Weiss,Roy P C Kessels,Bastiaan R Bloem

doi:10.1007/s00415-012-6419-4

Abstract

The objective of this study is to investigate the value of dual-task performance for the prediction of falls in patients with Parkinson’s disease (PD). Two hundred sixty-three patients with PD (H&Y 1–3, 65.2 ± 7.9 years) walked two times along a 10-m trajectory, both under single-task and dual-task (DT) conditions (combined with an auditory Stroop task). To control for a cueing effect, Stroop stimuli were presented at variable or fixed 1- or 2-s intervals. The auditory Stroop task was also performed alone. Dual-task costs were calculated for gait speed, stride length, stride time, stride time variability, step and stride regularity, step symmetry and Stroop composite scores (accuracy/reaction time). Subsequently, falls were registered prospectively for 1 year (monthly assessments). Patients were categorized as non-recurrent fallers (no or 1 fall) or recurrent fallers (>1 falls). Recurrent fallers (35%) had a significantly higher disease severity, lower MMSE scores, and higher Timed “Up & Go” test scores than non-recurrent fallers. Under DT conditions, gait speed and stride lengths were significantly decreased. Stride time, stride time variability, step and stride regularity, and step symmetry did not change under DT conditions. Stroop dual-task costs were only significant for the 2-s Stroop interval trials. Importantly, recurrent fallers did not show different dual-task costs compared to non-recurrent fallers on any of the gait or Stroop parameters. These results did not change after correction for baseline group differences. Deterioration of gait or Stroop performance under dual-task conditions was not associated with prospective falls in this large sample of patients with PD.

Highlights

Falling is a common and incapacitating complication of Parkinson’s disease (PD) [1]
The objective of this study is to investigate the value of dual-task performance for the prediction of falls in patients with Parkinson’s disease (PD)
Even in the group of frequent fallers ([5 falls/year; larger dots in Fig. 2), we could not determine different priority strategies compared to non-fallers. In this large-scale study we evaluated whether dual-task performance was associated with future falls in patients with PD

Summary

Introduction

Even in early disease stages a considerable number of patients with PD fall [2]. To identify these fallers, it is necessary to develop a sensitive. J Neurol (2012) 259:1840–1847 and specific measure to predict which patients are at high risk of future falls in a timely manner. This is still not adequately possible using existing prediction algorithms. A well-proven paradigm to assess attentional demands of gait is to add a secondary cognitive task and to compute the cost of dual tasking [5, 6]. When the attentional demands of both tasks together exceed the available capacity, the performance of one or both tasks will deteriorate compared to the respective single-task performance

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Conclusion