Multiple sclerosis (MS) is presumed to be an autoimmune disorder, but beyond that, is not fully understood. What is understood is some of the terrible symptoms that can occur with MS, including: blurred or double vision, muscle weakness, lack of coordination, imbalance, impaired walking/standing, speech impediments, tremors, hearing loss, difficulties with concentration, attention, memory, and poor judgement. To those who read this blog and/or have personal knowledge of brain injury, the symptoms should be apparent, but for the purpose of this article it is necessary to spell out some of the symptoms of moderate to severe brain injuries: dilations of the pupils, seizures, slurred speech, weakness, loss of coordination, restlessness or agitation, chronic headaches, increased confusion, lightheadedness, dizziness, blurred vision, ringing in the ears, fatigue, behavioral or mood changes and trouble with memory, concentration, attention, and thinking. As can be seen, even in these abbreviated lists, MS and TBI exhibit many of the same symptoms. For this reason, it is not a surprise to find that the two may have a connection – however, the results of multiple NIH-funded studies on the subject have not, as of yet, been able to determine what exactly is this connection.
In 2006, for example, in a study entitled “Risk of multiple sclerosis after head injury: record linkage study,” the NIH concluded: “There was no significant increase in the risk of MS at either short or long time periods after head injury.” However, six years later, in 2012, the NIH released a study with the title: “Increased risk of multiple sclerosis after traumatic brain injury: a nationwide population-based study.” In 2016, a study essentially took the middle-ground, concluding that, “The presence of comorbidities in patients with MS is associated with brain injury.” (Therefore, they concluded that if someone has another disorder, as well as MS, they may be more likely to have a brain injury.)
The “cause or effect” confusion is recognized by researchers, as in 2017 a scientist at Harvard University remarked, “Some studies suggest that head injuries might be a risk factor for MS… On the other hand, it’s not an easy thing to study because researchers would never intentionally cause head injuries to see if they cause MS.” However, this Harvard study did find that having a single concussion during childhood gave a person a 22% higher rate of MS and the percent was doubled for those who had more than one concussion.
Whether MS and TBI have a cause-and-effect relationship or not, their similar symptoms may mean that exercise is of particular benefit to those with multiple sclerosis, just as it is to those with brain injury. To test this hypothesis, the NIH has funded a study at the University of Alabama at Birmingham and at the New Jersey-based Kessler Foundation specifically to determine the benefit of exercise training for cognitive deficits in MS. The study will see if 3-months of treadmill walking for the participants improves their cognitive processing speed, brain volume, and functional connectivity. “The study may provide the first Class 1 evidence for the effects of treadmill walking exercise training as a rehabilitative approach to cognitive deficits in people with multiple sclerosis,” says Brain Sandroff, PhD of UAB and principal investigator of the study.