Heart-Brain Retraining: Forced Aerobic Exercise for Stroke Rehabilitation

Stroke is the leading cause of disability in the United States with approximately 795,000 new or recurrent strokes per year. An estimated two thirds of patients post-stroke cannot incorporate the affected upper extremity (UE) into their activities of daily living. In addition, stroke survivors experience a 60% decrease in cardiovascular capacity, which contributed to disability and diminished quality of life. Developing rehabilitation techniques to optimize motor recovery while improving cardiovascular endurance would benefit the stroke population.

Animal studies using a forced exercise (FE) paradigm, in which the rodent is exercised on a motorized treadmill at a rate greater than its voluntary rate, indicate an endogenous increase in neurotrophic factors such as brain-derived neurotrophic factor (BDNF) and glial-derived neurotrophic factor (GDNF). These neurotrophic factors are thought to underlie neuroplasticity and motor learning. It is hypothesized that patients with stroke, due to decreased motor cortical output, cannot sustain high rates of voluntary exercise necessary to trigger the endogenous release of neurotrophic factors; therefore, forced-exercise is necessary to augment their voluntary efforts and will be superior to voluntary exercise in facilitating motor recovery. When coupled with repetitive task practice (RTP) of the UE, an effective form of UE rehabilitation, FE will prime the brain for neuroplasticity. We have developed a safe and effective method of delivering forced-exercise to Parkinson's disease (PD) patients (NIH R21HD056316). Clinical and imaging data with PD patients indicate forced-exercise, but not voluntary exercise, triggers a neurophysiologic response in the central nervous system resulting in global improvements in motor and non-motor functioning and increased cortical and subcortical activation. The aim of this project is to conduct a preliminary trial to compare the effects of forced to voluntary exercise when coupled with RTP in promoting the recovery of motor function in patients with stroke.