The Effect of Acute Exercise on Cardiac Autonomic, Cerebrovascular, and Cognitive Function in Spinal Cord Injury

The aims of this proposal are to: 1) investigate whether individuals with spinal cord injury (SCI) demonstrate cardiac autonomic, cerebrovascular, and cognitive dysfunctions compared to non-injured age- and sex-matched controls in the following conditions: supine rest and head-up tilt/face-cooling test; 2) examine if autonomic completeness/ incompleteness, physical activity, and psychological distress are predictors for dysfunctions during supine rest and head-up tilt/face cooling conditions in SCI individuals; 3) examine if one bout of moderate-intensity aerobic exercise temporarily improves cardiac autonomic and cerebrovascular functions and thereby improves cognition when in supine rest and head- up tilt/face cooling conditions. The study will include an initial visit and an experimental visit to our lab. Three groups of participants will be included in this study: Group 1, SCI with acute exercise; group 2, SCI with rest-control; and group 3, age- and sex-matched non-injured individuals. Cardiovascular variables, such as heart rate variability, blood pressure variability, and cerebrovascular variables, such as cerebral blood flow velocity and oxygenated hemoglobin, and cognitive performance will be examined. The investigator hypothesizes that individuals with SCI will have impaired cardiac autonomic, cerebrovascular, and cognitive functions compared to the non-injured controls, and an acute exercise can improve those functions. Autonomic completeness/incompleteness, physical activity, and psychological distress are significant factors that predict cardiac autonomic, cerebrovascular, and cognitive functions in individuals with SCI.