For people with multiple sclerosis, can exercise change the brain?

For people with multiple sclerosis, can exercise change the brain?

Multiple sclerosis (MS) is a condition of unknown cause in which the covering lining of nerve fibers (called myelin) is damaged. Myelin is like insulation on a wire — when it is damaged, nerve impulses are not transmitted properly. This leads to an array of symptoms including weakness, vision problems, numbness, tingling and poor coordination or imbalance that can be debilitating.

MS is thought to develop when the immune system mistakenly attacks the central nervous system, including the brain and spinal cord. The severity of the disease varies. The most common pattern is one in which symptoms wax and wane. People who experience this are described as having “relapsing-remitting” disease.

Although there are more and better treatments for multiple sclerosis than ever before, there is no known cure. And the disease can progress even with the best treatments.

A recent study suggests that exercise may alter the brain

A recent study looks at exercise as a potential treatment for people with relapsing-remitting multiple sclerosis. What’s different, and exciting, about this study is that it not only analyzed the impact of exercise on symptoms of the disease, it also assessed how the brain changed with exercise treatment.

As published in the Multiple Sclerosis Journal, researchers enrolled 35 patients with relapsing-remitting MS. Half began a 24-week program of twice-weekly supervised exercise, while the other half continued to see their doctors for routine care. At the end of 24 weeks, the assignments reversed (although the group assigned to start with exercise could continue unsupervised exercise). The exercise program included progressive resistance training such as free weights, elastic bands, or exercise machines with increasing resistance over time. After the exercise program, researchers evaluated each study volunteer with measures of function, disability, and brain MRI.

Here’s what they found after the period of exercise.

–Measures of overall function improved while measures of disability did not change.

–Overall MRI findings (including brain volume and damage from MS) did not change. Since MRI findings of MS damage tend to worsen over time, this could suggest that exercise might keep MS from worsening, or slow its progression.

–Certain parts of the brain appeared to “thicken” by MRI (suggesting preservation of brain tissue or even regeneration). However, this was observed for only 19 of 74 brain areas examined.

What does this mean?

These findings are intriguing and potentially quite important. And this is not the only study looking at the capacity of exercise to change the brain. Previous studies of the healthy elderly who exercise, those with Parkinson’s disease who exercise, and practitioners of tai chi have found evidence of brain changes by MRI.

Even so, the real importance of this study is uncertain because:

–Even though the study subjects with MS improved with exercise, the overall appearance of the brain, including evidence of damage, did not improve.

–The relevance of the MRI changes is not entirely clear. We don’t know whether areas of “cortical thickening” function normally or account for improved symptoms.

–The study was quite small and short-term. Relapsing-remitting MS cycles through periods of improvement and worsening. So longer-term studies are needed before we know whether improvements associated with exercise are actually due to exercise, reflect the pattern of the disease, or have some other cause.

In conclusion

Clearly, improvement in MS symptoms that seems related to exercise is reason to continue recommending physical activity for this condition. Supervised exercise may be helpful, with little chance of causing serious side effects. I think that in the future we will see more and more research into non-medication treatments of MS and other chronic diseases.

Many people, myself included, believe that the usefulness of non-medication approaches for chronic disease may be underrecognized. While it seems unlikely that exercise alone can reverse brain damage from MS or cure the disease, it might play an important role when combined with other standard treatments, including medications.

(Robert H. Shmerling, M.D., is faculty editor of Harvard Health Publications.)