Study uses fMRI to assess changes in brain after exercise intervention

Areas of the brain responsible for pain processing and cognitive performance changed in fibromyalgia patients who exercised following a medication holiday, say researchers from Georgetown University Medical Center. They say the changes indicate brain functioning is more streamlined after an exercise intervention because less of the brain-s resources is devoted to processing bothersome fibromyalgia perceptions such as pain.

The study, presented at the Society of Neuroscience-s annual meeting, Neuroscience 2011, used functional MRI scans to assess changes in the brain. Researchers observed a decrease in brain activity in areas responsible for memory and pain control after fibromyalgia patients took part in an exercise regimen.

-The decreased brain activity we see in the area of cognition suggests that the brain is working more efficiently,- explains Brian Walitt, M.D. M.P.H., director of the Fibromyalgia Evaluation and Research Center at Georgetown University Medical Center and senior study author. -We also see less brain activity in areas responsible for pain processing which might be aiding that efficiency.- Walitt cautions that more research needs to be conducted before suggesting a change in clinical care for fibromyalgia.

Fibromyalgia is a medical disorder characterized by widespread pain, fatigue, disordered sleep, and cognitive changes. It is regarded as an interoceptive disorder in that it has no apparent cause, Walitt says. -In conditions like this, the body perceives something by mistake.- The pain is not psychosomatic, but is real and likely produced by the central nervous system, he says.

To that end, the research team used fMRI to -provide a definitive measure of cognitive functioning, so that we can more scientifically measure the effect of exercise,- says Manish Khatiwada, M.S., who will be presenting the results. -This is a novel approach to the study of fibromyalgia.- (Khatiwada is working in the laboratory of co-author John VanMeter, Ph.D., director of the Center for Functional and Molecular Imaging.)

For this study, the researchers enrolled eighteen women with fibromyalgia, and gave them a baseline fMRI to assess working memory and questionnaires about their well-being and pain while they were on medication. They then were told not to use their medications for a -washout- period, and had a second fMRI and memory testing. After six weeks, they had another assessment. The final scan was taken after the volunteers engaged in a six-week period of exercise, which involved three 30-minute sessions of aerobic exercise each week with a trainer.

Memory and pain typically worsen in patients after stopping their medication - which was the experience of patients in this study. After six weeks of exercise, however, patients reported an improvement in overall well-being. However, their performance in the memory task did not change significantly when compared to their baseline study measurements. Despite a change in memory test performance, brain activity in the memory task and pain processing areas of the brain decreased.

-What we see is a less interference by pain activity which could be contributing to the decrease in activity in the memory section. Basically, the brain is using less energy for the same task,- Walitt says.