Simultaneously measuring gait and cognitive performance in cognitively healthy and cognitively impaired older adults: the Basel motor-cognition dual-task paradigm.

OBJECTIVES: To investigate dual-task performance of gait and cognition in cognitively healthy and cognitively impaired older adults using a motor-cognition dual-task paradigm.
DESIGN: Cross-sectional retrospective study.
SETTING: The Basel Memory Clinic and the Basel Study on the Elderly (Project BASEL). PARTICIPANTS: Seven hundred eleven older adults (mean age 77.2±6.2, 350 (49.2%) female and 361 (50.8%) male). MEASUREMENTS: Gait velocity and cognitive task performance using a working memory (counting backward from 50 by 2s) and a semantic memory (enumerating animal names) task were measured during single- and dual-task conditions. Gait was assessed using the GAITRite electronic walkway system. Cognitive impairment was defined as a score less than 25 on the Mini-Mental State Examination.
RESULTS: During dual tasks, participants reduced gait velocity (P<.001) and calculated fewer numbers (P=.03) but did not enumerate fewer animals and did not make more errors or repetitions (P>.10). Cognitively impaired individuals had lower baseline gait velocity and a greater reduction in gait velocity but not cognitive performance during dual tasks than cognitively healthy participants (P<.01).
CONCLUSION: Gait velocity was lower during both dual tasks, whereas decrease in cognitive performance depended on the cognitive ability needed in the dual-task condition. Cognitively impaired individuals generally have poorer baseline performance and greater dual task-related gait velocity reduction than those who are cognitively healthy. Future research should include different conditions for gait to determine adaptive potentials of older adults.