Aerobic exercise has the potential to restore function in adults with multiple sclerosis (MS) and thalamic atrophy — a patient population at increased risk for progressive physical and cognitive decline.
In a cross-sectional study, aerobic fitness was strongly correlated with standard assessments of cognition and walking ability in MS patients with thalamic atrophy, but not in peers without thalamic atrophy.
The study provided preliminary evidence of "strong, selective associations between aerobic fitness, cognitive processing speed, and walking endurance in adults with MS-related thalamic atrophy," the investigators wrote.
The results are "exciting as we can potentially optimize aerobic exercise training trials that target specific groups of people with MS to maximize the chances of restoring functions in those patients," first author Brian M. Sandroff, PhD, senior research scientist, Kessler Foundation, West Orange, New Jersey, told Medscape Medical News.
The study was published online June 19 in the Journal of Neurology.
Clinical, Research Implications
Historically, lesion burden and lesion activity over time have been the most important prognostic markers of MS, Sandroff explained.
However, brain atrophy, including in the thalamus, is a "particularly" important biomarker that is increasingly assessed in clinic and included as an endpoint in MS clinical research, he noted.
The investigators sought to determine whether aerobic fitness was differentially associated with cognitive processing speed and walking endurance in adults with MS with and without thalamic atrophy.
The study enrolled 44 adults with MS, all of whom were able to walk. They completed a graded exercise test to assess peak oxygen uptake (VO2), the Symbol Digit Modalities Test (SDMT) to assess cognitive ability and the 6-minute walk test (6MW) to assess walking ability. MRI scans revealed thalamic atrophy in 25 patients.
After controlling for age, Expanded Disability Status Scale (EDSS) score and global MRI measures of atrophy, aerobic fitness (VO2) was strongly correlated with cognitive function (SDMT scores, P < .01) and walking ability (6MW performance, P < .01) in patients with thalamic atrophy, but not in those without thalamic atrophy.
"As aerobic fitness more strongly correlated with cognitive processing speed and walking endurance in those who presented with thalamic atrophy, this may support the development of a subsequent aerobic exercise training intervention for improving cognitive processing speed and walking endurance as primary outcomes in persons with MS who present with MS-related thalamic atrophy," said Sandroff.
"As thalamic atrophy is considered a strong biomarker for MS neurodegeneration, such a trial would represent the first test of aerobic exercise training for restoring function, particularly cognitive processing speed and walking endurance, in those who present with objective MS-related central nervous system damage, as there have been no rehabilitation trials in MS that have targeted patients who present with brain atrophy," he added.
Aerobic Exercise 'Strongly' Encouraged
Reached for comment, Eoin Flanagan, MBBCh, neurologist, Mayo Clinic, Rochester, Minnesota, noted that the thalamus is the body’s "relay station" that processes sensory signals from nerves, and loss of brain tissue in this region of the brain in MS is considered a marker of nerve degeneration.
In this study, said Flanagan, "higher levels of fitness seemed to be protective and were associated with better cognition and walking endurance in persons with MS who have thinning in this part of the brain."
"Thus, the main takeaway is that aerobic exercise may be particularly helpful in MS patients with nerve degeneration and should be strongly encouraged," Flanagan told Medscape Medical News.
The study was supported by an investigator-initiated grant from EMD Serono, Inc and the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health. Sandroff and Flanagan reported no relevant conflicts of interest.
J Neurol. Published June 19, 2022. Abstract.
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Cite this: Exercise May Help Restore Function in MS-Related Thalamic Atrophy - Medscape - Sep 23, 2022.