Cognitive-Motor Interference in Multiple Sclerosis: A Systematic Review of Evidence, Correlates, and Consequences

Abstract

Individuals with multiple sclerosis (MS) regularly exhibit deficits in motor and cognitive function. Recent evidence suggests that these impairments are compounded when motor and cognitive task are performed simultaneously such as walking while talking. The changes incurred during simultaneous performance of motor and cognitive tasks are a result of cognitive-motor interference (CMI) and operationalized as dual task costs (DTC). Recently in MS, research has been conducted to understand and analyze the impact of CMI. The purpose of this paper was to review the current literature related to the evidence, correlates, and consequences of CMI in MS. Relevant literature was collected from the results of a PubMed search for terms including “Cognitive-motor interference” or “Cognitive-motor interaction” or “Dual task” and “multiple sclerosis.” Overall, 20 papers were included for review which focused on CMI during balance and walking tasks. The finding that there is a lack of evidence pertaining to changes in the cognitive domain as well as to the specific consequences of CMI in MS was noted. Future work should aim to fill these gaps and ultimately investigate the usefulness of targeted interventions in reducing the deleterious effects of CMI in individuals with MS.

Effects of dual tasks and dual-task training on postural stability: a systematic review and meta-analysis

“…Boes et al21 suggested that since the patients with neurological impairments such as multiple sclerosis, stroke, Parkinson’s disease, and elderly participants have cognitive deficits, it is possible that the neurological capacity for these patients would be even less in terms of the aforementioned models. However, the findings of systematic reviews conducted by Learmonth et al31 and Wajda and Sosnoff30 concluded minimal effects of cognitive–motor interferences on postural stability for patients with multiple sclerosis and their healthy counterparts. The meta-analysis conducted by Learmonth et al31 revealed a small effect size of −0.11.…”

“…Boisgontier et al,6 Ruffieux et al,26 and Smith et al29 in their review studies concluded that application of dual task on fall-prone population groups results in postural instability and poor cognitive performance. However, minimal effects of cognitive–motor interference have been reported in a few reviews for diseased fall-prone population groups, which theoretically should exhibit poorer cognitive resources as compared to their healthy older counterparts 30,31. Therefore, there is a need to determine specific factors that in terms of complexity for a cognitive or motor task might result in differential effects on stability.…”

Effect of Cognitive Demand on Functional Mobility in Ambulatory Individuals with Multiple Sclerosis

“…Post hoc analysis showed that controls did not differ from people with MS and no mobility problems (P > .99) but did differ from the other two groups (P = .04 and .003); people with MS gait impairment are not clear, but several possibilities exist. Based on the theoretical tenets of the attentional capacity model, 31 it is suggested that individuals with MS who have mobility impairment require greater attentional resources during mobility tasks 16 compared with those without impairment. Consequently, an additional cognitive load further influences their mobility performance.…”

“…16 It was also noted that most of these investigations focused on steady-state straight-line walking. Everyday living requires movements that go beyond solely walking for functional mobility, including turning, standing up, and sitting down, for example.…”

Neuroimaging of Human Balance Control: A Systematic Review

“…Further analysis of balance control paradigms suggests that there are significant opportunities for innovation in neuroimaging research within this domain, which include: Researchers utilizing neuroimaging modalities in the balance control domain have a clear opportunity to couple these modalities with sensory and mechanical balance challenges, including experimental manipulation of optical flow, vestibular inputs, and conditions that impair multi-sensory integration.There is evidence that cognitive loading in patients with neurological disorders, such as Parkinson's disease, or in advancing age impacts the ability to main upright stance (Wajda and Sosnoff, 2015) and may increase risk of falls. These populations should continue to be included in future research to elucidate the neural mechanisms governing and potential compensatory mechanisms involved in balance control responses.…”