Association between physical fitness and cognitive function in multiple sclerosis: does disability status matter?

Area of Science:

• Neurology
• Rehabilitation Medicine
• Exercise Science

Background:

• Cognitive impairment is a common and disabling symptom in multiple sclerosis (MS).
• Exercise training is a potential strategy to manage cognitive decline in MS.
• Evidence linking physical fitness to cognitive function across MS disability levels is limited.

Purpose of the Study:

• To investigate the relationship between aerobic capacity, lower limb muscle strength, and cognitive functions in individuals with varying MS disability.
• To assess cognitive processing speed, verbal memory, and visual memory in relation to physical fitness metrics.

Main Methods:

• A cross-sectional study involving 62 participants with mild, moderate, and severe MS disability.
• Neuropsychological tests included the Symbol Digit Modalities Test (SDMT), California Verbal Learning Test-2 (CVLT-2), and Brief Visuospatial Memory Test-Revised (BVMT-R).
• Aerobic capacity (peak oxygen consumption) and muscular strength (peak knee torque) were measured.

Main Results:

• Aerobic capacity and muscular strength correlated with SDMT scores (r = .35-.41) in the overall sample, but not with CVLT-2 or BVMT-R scores.
• In individuals with mild MS, aerobic capacity (r = .42) and knee flexor strength (r = .39) were associated with SDMT scores.
• These associations were not significant in participants with moderate or severe MS disability.

Conclusions:

• Findings suggest that aerobic capacity and muscular strength are associated with cognitive processing speed in MS, particularly in milder forms.
• Aerobic and resistance exercise interventions should be considered for improving cognitive processing speed in individuals with mild MS.
• Further research may explore tailored exercise programs for different MS disability levels.