Exercise Improves Brain Connectivity in Parkinson’s

Parkinson's Disease (PD) is a brain disorder that causes tremors and difficulty with movement and walking, and most commonly affects people over the age of 50.  Chintan Shah, from The Cleveland Clinic (Ohio, USA), and colleagues studied 26 patients with stage II to III Parkinson's disease, ages 30 to 75 years, who were randomly assigned to either  voluntary or forced levels of exercise on a stationary bike for 8 weeks. Forced levels were about 30% above their normal exercise rates, and were achieved by riding a tandem bike powered by a graduate student. Brain scans were done at baseline, after the 8 weeks of exercise, and then again 4 weeks after stopping exercise. Shah and colleagues correlated brain activity and connectivity data with average pedaling rates. The researchers found that certain regions of the brain showed a strengthening of connectivity with higher pedaling rates, while others showed a decrease in connectivity -- a finding that remained significant 4 weeks after stopping exercise.  Specifically, patients who pedaled faster tended to show increases in connectivity between the thalamus and the primary motor cortex, while at the same time showing decreases in connectivity between the contralateral motor cortex, a region known to help compensate for the deficits seen in Parkinson's disease.  Finding that faster pedaling is the key factor related to the improvements,  the study authors report that: "They didn't have to have a good cardiovascular response, as long as they just moved their legs at that pedal rate."