Does Executive Function Influence Walking in Acutely Hospitalized Patients With Advanced Parkinson's Disease: A Quantitative Analysis

Abstract

Introduction: It is well-known that, in Parkinson's disease (PD), executive function (EF) and motor deficits lead to reduced walking performance. As previous studies investigated mainly patients during the compensated phases of the disease, the aim of this study was to investigate the above associations in acutely hospitalized patients with PD.

Methods: A total of seventy-four acutely hospitalized patients with PD were assessed with the delta Trail Making Test (ΔTMT, TMT-B minus TMT-A) and the Movement Disorder Society-revised version of the motor part of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS III). Walking performance was assessed with wearable sensors under single (ST; fast and normal pace) and dual-task (DT; walking and checking boxes as the motor secondary task and walking and subtracting seven consecutively from a given three-digit number as the cognitive secondary task) conditions over 20 m. Multiple linear regression and Bayes factor BF₁₀ were performed for each walking parameter and their dual-task costs while walking (DTC) as dependent variables and also included ΔTMT, MDS-UPDRS III, age, and gender.

Results: Under ST, significant negative effects of the use of a walking aid and MDS-UPDRS III on gait speed and at a fast pace on the number of steps were observed. Moreover, depending on the pace, the use of a walking aid, age, and gender affected step time variability. Under walking-cognitive DT, a resolved variance of 23% was observed in the overall model for step time variability DTC, driven mainly by age (β = 0.26, p = 0.09). Under DT, no other significant effects could be observed. ΔTMT showed no significant associations with any of the walking conditions.

Discussion: The results of this study suggest that, in acutely hospitalized patients with PD, reduced walking performance is mainly explained by the use of a walking aid, motor symptoms, age, and gender, and EF deficits surprisingly do not seem to play a significant role. However, these patients with PD should avoid walking-cognitive DT situations, as under this condition, especially step time variability, a parameter associated with the risk of falling in PD worsens.

Keywords: Parkinson's disease; aged; dual task; executive functions; straight walking; wearable sensors.

Figure 1

Box plots for all walking parameters over all walking conditions. For the five walking parameters, (A) number of steps, (B) gait speed (meters per second), (C) double limb support (DLS, seconds), (D) asymmetry (ASYM, seconds), and (E) step time variability (STV, seconds), the medians (thick black horizontal lines), the interquartile range (IQR, black-bordered boxes), and lower and upper whiskers (values within ±1.5xIQR), single-subject data points (black circles) are given for walking conditions of a single task normal pace (green, 1), a single task fast pace (violet, 2), the dual-task walking-cognitive (yellow, 3), and the dual-task walking-motor (gray, 4).

Figure 2

Correlation plots for ΔTMT with all walking parameters. In (A), for the single-task normal pace walking condition (ST Normal, green) and the single-task fast pace condition (ST Fast, gray), all five walking parameters, i.e., number of steps, gait speed (in meter per seconds, m/s), double limb support (DLS), asymmetry (ASYM), and step time variability in seconds (STV, s) are shown on the ordinates, the delta of Trail Making Test (part B minus part A, ΔTMT) is on the abscissas. Sample size N is given as well as Spearman's rank correlation (ρ) between ΔTMT and each walking parameter, significant correlation coefficients are marked with ^* (level of significance p ≤ 0.05), non-significant ones are marked with (n.s). For each condition, data points (dots) and regression lines with confidence intervals (lines with surrounding boxes) are shown. In (B) the same is shown for the dual-task motor-cognitive walking condition (DT motor-cognitive, green) and the dual-task motor-motor condition (DT motor-motor, gray). In (C), for DT motor-cognitive walking condition the dual-task costs while walking in percentage (DTC_Walking, %) for all five walking parameters are shown on the ordinates, the delta of Trail Making Test (part B minus part A, ΔTMT) are on the abscissas as well as Spearman's rank correlation (ρ) between ΔTMT and each DTC_Walking. Data points (gray dots) and regression lines with confidence intervals (blue lines with surrounding gray boxes) are shown for each parameter. The same is shown in (D) for the DT motor-motor walking condition.

Figure 3

Correlation plots for significant multiple linear regression models for gait speed, STV, number of steps and DTC_Walking for STV. In (A), for single task normal pace walking condition (ST Normal, green) and single-task fast pace condition (ST Fast, gray), gait speed (in meter per seconds, m/s) is shown on the ordinates, the total score of the Movement Disorder Society-revised version of the motor part of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS III) and walking aid (0 = “no walking aid,” 1 = “walking aid”) are on the abscissas. Sample size n is given as well as Spearman's rank correlation (ρ) between gait speed and each parameter. For each condition, data points (dots) and regression lines with confidence intervals (lines with surrounding boxes) are shown, and significant correlation coefficients are marked with ^* (level of significance p ≤ 0.05), ^** (level of significance p ≤ 0.01), and ^*** (level of significance p ≤ 0.001), non-significant ones are marked with (n.s.). In (B), the same is shown for step time variability (STV in seconds, s) on the ordinates, and walking aid, gender (0= “men,” 1= “women”), and age on the abscissas. In (C) for ST fast pace number of steps is shown on the ordinates, MDS-UPDRS III and walking aid are on the abscissas. Here, data points (gray dots) and regression lines with confidence intervals (blue lines with surrounding gray boxes) are given for each parameter. In (D), the same is shown for DT walking-cognitive walking condition for dual-task costs while walking in percentage (DTC_Walking, %) of STV on the ordinate and age on the abscissa.