Dual-Task Effects During a Motor-Cognitive Task in Parkinson's Disease: Patterns of Prioritization and the Influence of Cognitive Status

Abstract

People with Parkinson's disease (PD) experience greater difficulties during dual task (DT) walking compared to healthy controls, but factors explaining the variance in DT costs remain largely unknown. Additionally, as cognitive impairments are common in PD it is important to understand whether cognitive status influences the strategies used during DT paradigms. The study aimed to (1) explore DT costs on gait and cognition during DT walking, (2) investigate factors associated with DT costs, and (3) to investigate to what extent patterns of DT costs and prioritization differed according to cognitive status. A total of 93 people with Parkinson's disease were examined when walking in single and DT conditions. Information regarding demographics, PD severity, mobility, and cognitive and affective symptoms was collected, and an extensive neuropsychological test battery was used to classify whether participants had mild cognitive impairment (PD MCI) or not (PD non-MCI). Dual task costs were observed across all gait domains except asymmetry. Cognitive status was associated with DT costs on both gait and cognition. Nonmotor experiences of daily living were further associated with DT cost on cognition, and TUG-cog associated with DT cost on gait. People with PD MCI had larger DT costs on gait than PD non-MCI. Strategies differed according to cognitive status, whereby PD MCI used a posture-second strategy, and PD non-MCI used a posture-first strategy. Once verified in future studies, these results can inform clinicians and researchers when tailoring DT training paradigms to the specific characteristics of people with PD.

Trial registration: ClinicalTrials.gov NCT03213873.

Keywords: Parkinson disease; cognition; gait; multitasking behavior.

Figure 1.

Overview of dual task effects on gait variables and the auditory Stroop task. *indicate those variables where the difference in performance between single and dual task was significant (**p < 0.001; *p < 0.05). A significant dual task cost means a decline in performance from dual task compared to single task.

Figure 2.

Patterns of individual dual task (DT) effects between cognition and gait speed (2a), and step time variability (2b), as well as prioritization shown as boxplots (median, interquartile range and outliers) between the cognitive task and gait speed (2c), and step time variability (2d) in the PD non-MCI and PD MCI groups respectively.