Dual-Task Gait Cognitive-Motor Interference as a Marker of Cognitive Impairment in Parkinson's Disease: A Systematic Review and Meta-Analysis

Cognitive impairment in Parkinson's disease (PD-CI) negatively affects mobility, independence, and quality of life. Dual-task (DT) gait testing, which captures cognitive-motor interference (CMI), has emerged as a promising, non-invasive method to detect PD-CI.

This systematic review and meta-analysis assessed the sensitivity of DT gait parameters-including stride length, gait speed, cadence, variability, and Timed Up and Go (TUG)-in differentiating PD-CI from cognitively normal PD (PD-NC), and examined subgroup differences between mild cognitive impairment (PD-MCI) and subjective cognitive decline (PD-SCD).

PubMed, Web of Science, and Embase were searched for observational studies comparing DT gait in PD-CI versus PD-NC. Random-effects meta-analyses estimated pooled effect sizes (Hedges' g), with subgroup and meta-regression analyses exploring task- and disease-related moderators.

DT stride length showed the largest impairment in PD-CI (g = -0.994, P < 0.001), followed by TUG (g = +0.850, P = 0.001), gait speed (g = -0.542, P = 0.001), cadence (g = -0.370, P = 0.002), and stride variability (g = +0.590, P < 0.001). Subgroup analyses indicated DT gait speed reliably differentiated PD-MCI from PD-NC (g = -0.59, P < 0.001), but not PD-SCI from other groups. Meta-regression showed shorter disease duration (≤5 years) and lower Hoehn & Yahr stage (<2) predicted larger DT impairments (P < 0.01), while age and sample size were non-significant.

DT gait parameters-especially stride length, gait speed, and TUG-are sensitive markers of PD-CI, with greatest utility at the PD-MCI stage. Standardized protocols and longitudinal validation are warranted.