Treadmill Walking Speeds Up Cognition in MS

Damian McNamara

October 11, 2018

BERLIN — A regimen of 12 weeks of treadmill exercises was associated with improvements in cognition in a small study of patients with multiple sclerosis (MS).

Researchers also reported this amount of exercise was associated with statistically significant improvements in information processing speeds on the Symbol Digit Modalities Test (SDMT).

Compared to baseline, "a four-point improvement on the SDMT suggests not only a statistically significant change, but that the improvement is clinically meaningful," Iris-Katharina Penner, PhD, of the Department of Neurology at the Heinrich-Heine-University and director of the COGITO Center for Applied Neurocognition and Neuropsychological Research in Düsseldorf, Germany, said.

It is "important to see a real translation to a benefit for our patients," Penner added.

The findings were presented here at the 34th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) 2018.

Cognitive Impairment Common

Major neuropsychiatric symptoms of MS, such as fatigue, depression/anxiety, and cognitive deficits, are highly prevalent and have "a large impact on the quality of life for our patients," Penner said.

Other researchers have estimated that 71% of people with MS experience cognitive difficulties. The results are based on surveys of more than 16,000 MS patients.

The rationale behind nonpharmacologic approaches, such as cognitive training or exercise, is that "they all try to support neuronal rewiring and try to translate connectivity changes into improvement of function," Penner said.

"This exercise topic is not without controversies," however, she said. Some previous studies support the benefit of exercise, but other studies do not show a positive effect on different cognitive domains.

"We need clinical trials of higher methodologic quality," Penner said. "There is a huge variability in studies in dose of the treatments. Nothing in the literature can help us know what is the dosage we need to help the brain reconnect and to show effects on function of the patient."

Behavioral Outcomes Improved

Enrollment for the study is ongoing; this analysis included 55 participants with MS. A total 15 participants completed 12 weeks of the treadmill walking intervention; 18 completed cognitive training using the BrainStim program on a computer; and another 22 completed a combination.

Penner presented the behavioral outcomes for an initial 32 participants. This cohort included 25 women (mean age, 47 years).

Penner and colleagues assessed the impact of exercise by comparing PDQ-20 scores at baseline and at week 12. Changes in SDMT scores were tracked to assess processing speed. They performed a comprehensive neuropsychological assessment before and after the intervention.

First analyses of the 32 patients with complete data indicate a significant improvement in both primary outcomes across all three training groups: PDQ-20: z = 3.093,P = .002.

These findings are supported by strong effect sizes for both measures: PDQ-20, d= 0.961; and SDMT, d= 0.692.

Evaluation of PDQ subscales showed significant improvements on attention and concentration, retrospective memory, and prospective memory (for each, P < .05).

Exercise and cognitive training are recommended early in disease course to derive benefit from still existing functional networks, Penner said.

Exercise and Cognitive Training

The research is ongoing, and the investigators plan to also assess secondary measures such as fatigue, quality of life, depression/anxiety, MRI and functional MRI findings, and more.

A meeting attendee asked whether the effects were sustained over time. Penner replied they have 6 months of follow-up data that they are still analyzing.

Another attendee asked how disabled the MS patients were in the current study. Penner and colleagues only included ambulatory patients with an Expanded Disability Status Scale score of 4.0 or less because the study required that patients go to the gym on their own.

A concern was raised by a third meeting attendee regarding the lack of a control group in the study. "If we train people on any task for 12 weeks, they will improve," he said.

"You are right, but it is difficult to conduct those kinds of studies [with exercise]," Penner said. "We were happy to include as many patients as we could with follow-up up to 1 year." She added, "We want to improve our patients, so I probably don't need a healthy comparison group."

"There are several studies now that show exercise improves cognition," session comoderator Dawn Langdon, PhD, reader in neuropsychology, Royal Holloway at the University of London, told Medscape Medical News when asked to comment.

"For a long time, all the exercise data were self-reported cognition outcomes, which you can't really rely on," she said. "But over the last few years, there are a good handful of exercise studies showing there is cognitive improvement. This fits into the trend."

Exercise studies are very hard to blind because patients know whether they are engaging in exercise or not, and this is a potential limitation, Langdon said.

The only other problem, a weakness of the study, was lack of a control group, she said. "Was it just that the patients felt better because they liked the attention? They were coming in for all these visits." A lack of a comparator group raises the possibility of multiple confounders, she said.

Teva supported this study. Dr Penner has received research support from Teva as well as honoraria for speaking at scientific meetings, has serv ed on scientific advisory boards, and has engaged in consulting activities. Dr Langdon has disclosed no relevant relationships.

34th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) 2018. Abstract 94, presented October 10, 2018.

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