Walking Stroop carpet: an innovative dual-task concept for detecting cognitive impairment

A Perrochon,^1,2,5 G Kemoun,^1,2 E Watelain,^3,4 A Berthoz<sup>5

1</sup>ISIS, Research Institute on Handicap and Aging, Paris; ²Université de Poitiers, Laboratoire Mobilité, Vieillissement et Exercice (MOVE), EA 6314, ³Université de Valenciennes, LAMIH, UMR CNRS 8201, ⁴Université Sud Toulon Var, HandiBio, EA 4322, La Garde, ⁵LPPA, UMR CNRS 7152, Collège de France, Paris, France

Background: Several studies have reported the potential value of the dual-task concept during locomotion in clinical evaluation because cognitive decline is strongly associated with gait abnormalities. However, current dual-task tests appear to be insufficient for early diagnosis of cognitive impairment.
Methods: Forty-nine subjects (young, old, with or without mild cognitive impairment) underwent cognitive evaluation (Mini-Mental State Examination, Frontal Assessment Battery, five-word test, Stroop, clock-drawing) and single-task locomotor evaluation on an electronic walkway. They were then dual-task-tested on the Walking Stroop carpet, which is an adaptation of the Stroop color–word task for locomotion. A cluster analysis, followed by an analysis of variance, was performed to assess gait parameters.
Results: Cluster analysis of gait parameters on the Walking Stroop carpet revealed an interaction between cognitive and functional abilities because it made it possible to distinguish dysexecutive cognitive fragility or decline with a sensitivity of 89% and a specificity of 94%. Locomotor abilities differed according to the group and dual-task conditions. Healthy subjects performed less well on dual-tasking under reading conditions than when they were asked to distinguish colors, whereas dysexecutive subjects had worse motor performances when they were required to dual task.
Conclusion: The Walking Stroop carpet is a dual-task test that enables early detection of cognitive fragility that has not been revealed by traditional neuropsychological tests or single-task walking analysis.

Keywords: stroop, dual-task, walking, mild cognitive impairment