Are Cognitive Subtypes Associated with Dual-Task Gait Performance in a Clinical Setting?

Background: Poor dual-task gait (walking while performing a cognitively demanding task) has been linked to progression to dementia in older adults with mild cognitive impairment (MCI). However, many of these findings come from research environments; gait performance across the cognitive spectrum has not previously been studied in a clinical setting. Objective: To examine whether patients from a memory clinic show differences in usual and dual-task gait speed and dual-task cost (DTC) based on cognitive diagnosis. Methods: Patients in the Aging Brain and Memory Clinic (London, ON) performed a usual gait walk and three dual-task gait walks: counting backwards by ones, naming animals, and counting backwards by seven (serial sevens) out loud. Patients were timed with a stopwatch over a six-meter path marked on the floor. One-way ANOVA was performed to evaluate associations between gait speed and DTC (%) across groups. Results: One hundred ninety-four patients with subjective cognitive impairment (SCI; n= 46), MCI (n= 77), or dementia (n= 71) were assessed. Performance in usual (p <0.001) and dual-task gait speed (counting gait p <0.001; naming animals p < 0.001; serial sevens p = 0.004) decreased across the spectrum of cognitive impairment. Patients with dementia had significantly higher DTC in both counting gait (p = 0.02) and naming animals (p = 0.04) conditions compared with patients with SCI and MCI, who had statistically similar DTC in all conditions. Conclusion: Dual-task gait performance significantly declines across the cognitive spectrum in a clinical setting. Dual-task gait testing may be used in conjunction with traditional assessments for diagnosing cognitive impairments.