Published April 4, 2013
An interdisciplinary team of UB researchers found that aerobic exercise may help restore normal cognitive function in patients who have suffered a concussion.
Their study also reveals hypermetabolic activity and other differences in the brains of those with post-concussion syndrome, offering an explanation for the mental exhaustion these patients often experience.
The 12-person study involved treating eight concussion patients, four with controlled aerobic exercise and four with stretching exercises that do not raise the heart rate. Their abilities were compared to those of four healthy participants.
In addition to symptoms, the researchers assessed cognitive function via functional magnetic resonance imaging tests while participants performed simple arithmetic tasks.
Patients and normal controls were similar in age, gender and athleticism.
Initially, all post-concussion patients showed abnormal function on advanced brain imaging studies.
After treatment, only the graded, aerobic exercise group returned to normal. These patients also experienced a significant decline in symptoms, such as improved sleep and concentration, compared to those treated with stretching exercise.
“It is rare to have such significant findings with a small sample study, and especially to find such powerful evidence that after a concussion, patients can actually return to normal brain function with graded exercise treatment,” says John J. Leddy, MD, clinical associate professor of orthopaedics and lead author on the paper.
Through imaging studies, the researchers discovered changes in the brains of post-concussion patients that "appear to arise from metabolic and physiologic changes rather than psychologic changes, as has been suggested in the past," says Leddy, who also directs UB’s Concussion Management Clinic.
“All patients showed a hypermetabolic state, revealing altered cerebral blood flow, compared to the sample of normal subjects,” he explains.
The study also provides evidence verifying the mental exhaustion post-concussion patients experience.
When figuring math problems, both patients and normal subjects performed with the same accuracy and speed, notes study co-author Barry S. Willer, PhD, professor of psychiatry. However, imaging studies showed that normal subjects used a few, specific regions of the brain, whereas post-concussion patients used multiple areas of the brain.
“Patients’ brains were lit up like Christmas trees, reflecting hyperactivity of metabolism," says Willer, who also serves as the clinic’s research director. This shows that post-concussion patients require far more mental resources to perform cognitively, offering an explanation for the mental exhaustion they often report.
“We hear about this often from students suffering from post-concussive effects,” Willer adds. “They can make it through the first two classes of the day, but their cognitive resources are all used up by the third class."
“It is wonderful when research evidence so carefully matches patients’ realities,” he says.
Imaging studies also showed less activation in key areas of the post-concussion brain, says co-author Robert Zivadinov, MD, PhD, professor of neurology, who directs the Buffalo Neuroimaging Analysis Center (BNAC).
These quieted areas include the cerebellum, responsible for balance and coordination, and the posterior cingulate, a relay station for multiple cognitive functions that is often underactive in studies of dementia patients.
The study also involved coauthors David Pendergast, EdD, professor of physiology and biophysics; Jennifer L. Cox, PhD, formerly research assistant professor of neurology and director of translational research at BNAC and now adjunct assistant professor of nursing; David Wack, PhD, research assistant professor of nuclear medicine; and John G. Baker, PhD, assistant professor of nuclear medicine.