June 22, 2020
Multiple Sclerosis News Today
Steve Bryson

Cognitive problems are common in people with multiple sclerosis (MS) but inadequately addressed by disease-modifying therapies, while cognitive rehabilitation and exercise training programs can be effective, a review study reported.

Research studies of exercise programs need to include larger groups of patients with demonstrated cognitive difficulties, however, and more pharmacological therapy trials need to place cognitive benefit as a primary goal, its researchers said.

The study, “Treatment and management of cognitive dysfunction in patients with multiple sclerosis,” was published in the journal Nature Reviews Neurology.

Difficulties with attention, working memory, long-term memory, information processing speed, and executive functions — all cognitive skills — are thought to affect around two-thirds of MS patients. Problems with social functioning and the ability to identify visual and spatial relationships (visuospatial) can also be present.

As a result, patients can struggle in the workplace, the community, and at the home in ways that can profoundly affect daily life.

Despite advancements in MS management, treatment options for cognitive impairment remain limited, and “regular objective assessment of cognitive functioning remains rare in clinical practice,” the researchers wrote.

Experts in cognitive research at the University of Alabama at Birmingham and the Kessler Foundation — a nonprofit organization that supports cognitive rehabilitation research in patients with neurological disabilities — analyzed current research to evaluate available treatments as well as promising approaches for treating cognitive deficits in MS.

Research into cognitive rehabilitation is growing in the MS community and has focused on improving attention, communication skills, and memory. Evidence, collected from both adult and pediatric patients, suggests that cognitive rehabilitation can have a long-term impact, and may improve cognition even with changes in the brain.

“Evidence suggests that cognitive rehabilitation is effective in MS-related cognitive dysfunction, and may confer long-lasting effects,” John DeLuca, PhD, study co-author and senior VP of research and training at Kessler Foundation, said in a press release.

“Access to cognitive rehabilitation therapy is likely to increase as remote options for delivery become more widely accepted, such as programs for home computers and telerehabilitation services,” DeLuca added.

Options such as attention process training have shown clear benefits, as have targeted software training programs like BrainHQ that can be used in the home.

Based on over 40 years of research consistently showing that exercise improves cognitive abilities across all ages groups, physical exercise programs — including aerobic training, resistance training, and balance training — has been used to manage MS-related cognitive decline. And exercise programs are recommended by the National Multiple Sclerosis Society,  the study noted.

Recent studies reported that exercise training involving a wide range of interventions improved processing speed, learning, memory, and executive functions.

But too few enrolled MS patients with evident cognitive difficulties, which is “problematic given that exercise can only be examined as a possible treatment for MS-related cognitive dysfunction if the participants demonstrate objective cognitive impairment,” the researchers wrote.

The optimal timing, dosage, and duration of exercise interventions also need to be determined.

“It is critical that larger-scale studies include participants with MS, including progressive MS, and target select cognitive outcomes,” DeLuca said. “As studies continue to evolve, clinical applications of exercise recommendations are likely to be implemented within the next ten years.”

The team also reported that the use of disease-modifying therapies (DMTs) may help with cognitive function, as these medicines are designed to prevent disease relapses. But evidence supporting the effectiveness of DMTs on cognition is limited, with no medications approved for this purpose. Clinical trials to support DMTs also fail to place cognition as a primary study goal.

“Insufficient evidence is currently available to support pharmacological approaches for treating cognitive impairment in patients with MS,” the researchers wrote.

“To determine the efficacy of a pharmacologic intervention for cognitive dysfunction, randomized controlled trials need to include cognition among their primary outcomes,” DeLuca said.

Overall, “cognitive impairment is a common and devastating manifestation of MS, and the identification of successful treatment approaches is essential,” the team concluded.

“People with MS and cognitive impairment deserve effective treatment, and it is important to provide currently available treatment options in clinical practice and to continually develop and evaluate optimized pharmacological, cognitive rehabilitation and exercise training therapies for future consideration,” they added.