An international team of multiple sclerosis (MS) experts report lack of association between cognition and physical activity and cardiorespiratory fitness in a large sample of individuals with progressive MS. These findings have important implications for studies involving exercise interventions aimed at treating the cognitive effects of MS.

The study was published recently in Multiple Sclerosis Journal. The authors represent Canada, the United States, Italy, the UK, Denmark, and Belgium.

The effects of exercise interventions on cognition are a focus of rehabilitation research in conditions associated with deficits and decline in cognition. Cognitive benefits of aerobic exercise have been reported in relapsing-remitting (non-progressive) MS and in age-related cognitive decline. One small pilot study conducted in progressive MS found an association between aerobic ergometer exercise and cardiovascular fitness, alertness, and verbal memory.

Analyzed Data from CogEx Study

To examine these associations, the authors analyzed baseline data from the CogEx study, a multi-national, multi-arm, randomized, blinded, sham-controlled trial looking at the effects of cognitive rehabilitation and aerobic exercise training on cognition and neuroimaging findings in 240 individuals with progressive MS. They measured cardiorespiratory fitness, free-living moderate-to-vigorous physical activity, and cognitive performance.

“Neither cardiorespiratory fitness nor free living physical activity correlated with cognitive performance in this study sample. This suggests that other mechanisms of action may mediate the potential effects of aerobic training on cognition in this population. The neuroimaging data collected in this trial may help clarify these underlying mechanisms.”  

— lead author Brian Sandroff, PhD, senior research scientist in the Center for Neuropsychology and Neuroscience Research at Kessler Foundation

The findings have important implications for randomized controlled trials in progressive MS.

“It’s clear that we need to carefully assess the outcome measures for studies of exercise and cognition in this population. Improving cognition and brain health is essential to maintaining quality of life for people with progressive MS. To achieve that, we need to expand our investigation of how exercise affects brain function.”

— co-author John DeLuca, PhD, Senior Vice President for Research and Training at Kessler Foundation

[Source(s): Kessler Foundation, EurekAlert]