Differential effects and discriminative validity of motor and cognitive tasks varying in difficulty on cognitive–motor interference in persons with multiple sclerosis

Abstract

Background: Cognitive–motor interference (CMI) has been well recognized in persons with multiple sclerosis (pwMS); however, there are limited data on effects of task difficulty. Objective: Examine (1) the effects of motor and cognitive tasks varying in difficulty on the magnitude of CMI and (2) the discriminative validity of CMI between pwMS and healthy controls (HC). Methods: Nine cognitive–motor dual-task (DT) conditions (combinations of three cognitive and three walking tasks) were examined. Outcome measures were DT-performance and dual-task cost (DTC) of gait parameters and correct answers. Task differences and overall group-effects were analysed by mixed model analysis, plus the Wilcoxon signed-rank tests or multivariate analysis of variances (MANOVAs), respectively. Results: Task effects were examined in 82 pwMS (Expanded Disability Status Scale (EDSS): 3.3 ± 1.0) and discriminative validity in a subsample (35 pwMS and 33 HC). Motor-DTC and DT-performance were affected by difficulty of both the cognitive task ( p < 0.001) and the walking condition ( p ⩽ 0.002), while cognitive-DTC only varied between cognitive tasks with a large difference in difficulty ( p ⩽ 0.005) and not between walking conditions ( p ⩾ 0.125). None of the DTCs differed between groups. Conclusion: CMI, and especially motor performance, is affected by difficulty of the DT. Although pwMS performed worse on the tasks than HC, none of the DT-conditions showed a discriminative DTC.

Patient-Reported Outcome Measures for Assessing Dual-Task Performance in Daily Life: A Review of Current Instruments, Use, and Measurement Properties

“…DAQ and DTQ were used as outcome measures, while DTSL was used for the inclusion criteria of an intervention study. In four studies, DTQ scores were compared between persons with MS and healthy controls, finding significant differences between groups that support the discriminative validity of the DTQ in MS [ 12 , 24 , 25 , 26 ]. Three studies used PROMs (DTQ, DAQ, DTSL) as an experimental outcome measure in intervention studies.…”

“…[ 29 ]. DTSL was used as an inclusion criterion in four studies ( n = 3 in MS, n = 1 in Parkinson’s disease) [ 12 , 24 , 28 , 30 ], two of which were intervention studies [ 28 , 30 ].…”

Cognitive-motor interference in people with mild to moderate multiple sclerosis, in comparison with healthy controls

“…Most studies conducted in PwMS have investigated CMI during walking intermittently on a ten-meter distance (10,21,35,36). Our study investigated CMI during a 2-minute continuous walking trial corresponding to approximately 150 meters, which to our knowledge has been done only once previously (18).…”

Motor sequence learning in a goal‐directed stepping task in persons with multiple sclerosis: a pilot study

“…The three cognitive tasks were (1) the serial subtraction sevens (SUB) tasks, (2) the word list generation task (WLG), and (3) the vigilance (VIG) task. These three were chosen on the basis of previous research showing the greatest interference for the subtraction task, 35 specific interference for pwMS compared with HC for the WLG, 32 and the VIG task as an externally interfering task in contrast with the previous two being internally interfering tasks. 57 (1) In the subtraction task, participants were asked to continuously subtract seven starting from a given number (152, 167, 174, 186, or 198).…”

“…[29][30][31] In pwMS, a growing number of studies have shown that gait or balance performance is reduced while performing a concurrent cognitive task. [32][33][34] Previous research reported pwMS to perceive more problems with dual tasking in daily life than healthy adults 35,36 and difficulties with dual tasking during walking to be related to higher risks of falls and lower quality of life. 37,38 Considering additionally the relevance of DT performance for daily life, 39 where many activities require successful locomotion in an environment that puts demands on cognitive functioning as well, the importance of assessing DT performance in pwMS is evident.…”