But what was interesting, Prakash said, was the significant differences between the more aerobically fit MS patients and those who were less fit.
Take, for instance, lesions, which are the characteristic feature of MS. Lesions are areas of inflammation in the central nervous system in which neurons have been stripped of myelin, an insulating protein.
"Physically fit MS patients had fewer lesions compared to those who weren't as fit and the lesions they did have tended to be smaller," Prakash said. "This is significant and can help explain why the higher-fit patients did better on tests of brain functioning."
Aerobic fitness was also associated with less-damaged brain tissue in MS patients, both the gray matter and white matter.
Gray matter is the cell bodies in the brain tissue, while white matter is the fibers that connect the various gray matter areas.
The study found that fitness in MS patients was associated with larger volume of gray matter, accounting for about 20 percent of the volume in gray matter. That's important, Prakash said, because gray matter is linked to brain processing skills.
"Even in gray matter that appeared relatively healthy, we found a deterioration in the volume in MS patients," she said. "But for some of the highest fit MS patients, we found that their gray matter volume was nearly equivalent to that of healthy controls."
Another MRI analysis involved the integrity of the white matter in the brain. In MS patients, the white matter deteriorates as the myelin is stripped from neurons. Again, higher-fit MS patients showed less deterioration of white matter compared to those who were less fit.
Overall, the three MRI tests in this study showed that parts of the brain involved in processing speed are all negativel
|Contact: Ruchika Shaurya Prakash|
Ohio State University