Does High-Intensity Aerobic Exercise Affect Cognitive Performance, Brain MRI Measures in MS?

Two studies that assessed high-intensity aerobic exercise in patients with multiple sclerosis (MS) found it was not associated with improved cognitive performance or brain MRI measures.

The first study, assessing cognitive performance, was published in the Multiple Sclerosis Journal. Patients were randomized into two groups: exercise, which included 24 weeks of supervised progressive aerobic exercise (PAE) followed by self-guided physical activity (n=43), and waitlist, which included 24 weeks of habitual lifestyle followed by supervised PAE. Patients were evaluated using the Brief Repeatable Battery of Neuropsychological tests (BRB-N), self-reported mood, and cardiorespiratory fitness.

When looking at the entire cohort, BRB-N scores did not change after PAE. In a subgroup of patients who were cognitively impaired (43%), a potentially clinically relevant improvement was observed in the Symbol Digit Modalities Test. Both the total cohort and cognitively impaired subgroup had improved cardiorespiratory fitness.

The second study, published in Neurology, analyzed the same two cohorts of patients, but the main outcome was percentage brain volume change (PBVC) after 24 weeks.

There were no changes in PBVC over the course of the study (mean between-group change, +0.12%; 95% confidence interval [CI], –0.27 to 0.51; P=0.55). Improvements were observed in the exercise group in cardiorespiratory fitness (+3.5 mL O2/min/kg; 95% CI, 2.0-5.1; P<0.01) and annualized relapse rate (0.00 [95% CI, 0.00-0.07] vs. +0.45 [95% CI, 0.28-0.61]; P<0.01).