WASHINGTON, DC—Among patients with Parkinson’s disease, aerobic exercise may improve white matter integrity in the putamen, according to research presented at the 67th Annual Meeting of the American Academy of Neurology. The increased white matter integrity may have no correlation with aerobic fitness or motor performance in these patients, however. In addition, exercise may not affect the volumes of the putamen and caudate.
“Aerobic exercise may modify the course of neurodegeneration or the effect of aging in Parkinson’s disease,” said Ergun Uc, MD, Associate Professor of Neurology at the University of Iowa in Iowa City. “These results need to be confirmed in randomized controlled trials. Further research is needed to determine if exercise can modify the course of Parkinson’s disease.”
Ergun Uc, MD
Dr. Uc’s findings came from a preliminary study of 60 patients with Parkinson’s disease that he and his colleagues conducted. The investigators sought to determine whether increasing aerobic fitness through moderate exercise would produce changes in motor function, cognition, quality of life, biomarkers, and functional or structural MRI. Eligible participants were between ages 50 and 80, independent, ambulatory, and nondemented. They had been on a stable antiparkinson regimen, but not in a formal exercise program.
The patients engaged in three 45-minute aerobic walking exercise sessions per week for six months. The exercise regime was similar to that recommended by the United States government in 2008, said Dr. Uc. The researchers used cycle ergometry to measure VO2 max, an indicator of aerobic fitness. In addition, participants underwent 3-T MRI at baseline and at the end of the six-week exercise regime.
Forty-nine of the 60 participants completed the study and exercised at approximately 47% of their heart rate reserve. The patients had significant improvements in VO2 max, gait speed, Unified Parkinson’s Disease Rating Scale (UPDRS) motor scores, depression, executive function, and quality of life. Changes in aerobic fitness correlated with improvements in quality of life and executive function. The lack of a control group, however, meant that the results were categorized as Class IV evidence.
Forty of the 49 study completers underwent MRI at baseline and at six weeks. They were not significantly different from the nine participants who did not undergo both MRIs. At baseline, the investigators found significant direct correlations between fractional anisotropy (FA) in the left putamen and VO2 max. They also found inverse correlations between VO2 max and mean diffusivity (MD) in the left and right putamen. The correlations remained after adjustments for age and gender. FA in the left substantia nigra had a direct correlation with VO2 max, but the correlation disappeared when the researchers adjusted the data for age and gender.
When the investigators examined the MRIs performed at six months, they found significant decreases in MD in the left putamen. FA tended to increase in the left putamen and left caudate. The volumes of the putamen and caudate did not change at six weeks, however. The researchers also found no correlations between changes in FA or MD in these regions at six weeks and changes in VO2 max or UPDRS motor score at six weeks. FA and MD in the substantia nigra did not change at six weeks.
—Erik Greb
