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

Study Overview
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Brief Summary
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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.

Official Title
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The Effect of Acute Exercise on Cardiac Autonomic, Cerebrovascular, and Cognitive Function in Spinal Cord Injury: A Pilot Study

Conditions
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Spinal Cord Injuries, Cardiovascular Abnormalities, Cerebrovascular Disease; Sequelae, Cognitive Impairment

Intervention / Treatment
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* Behavioral: One bout of moderate-intensity sub-maximal aerobic exercise


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Spinal cord injury group: Males or females with chronic SCI (i.e. at least 6 months after the initial injury) International Standard for Neurological Classification of SCI (ISNCSCI) A-D Neurological level of injury C6 or below 18-55 years old Proficient in English Able to detect middle cerebral artery blood velocity (MCAv) and/or posterior cerebral artery blood velocity (PCAv) signals through TCD Non-injured controls: Males or females without SCI 18-55 years old Proficient in English Able to detect MCAv and/or PCAv signals through TCD Exclusion Criteria: Cardiovascular, pulmonary or respiratory diseases, or diabetes mellitus, any other diseases/disorders affecting cardiac autonomic nervous system, such as glaucoma and attention deficit hyperactivity disorder (ADHD) Color Blindness Pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Allocation: Non-Randomized
Intervention Model: Factorial Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: CON<br>Age-and sex-matched healthy controls with exercise intervention | Behavioral: One bout of moderate-intensity sub-maximal aerobic exercise<br>* The intervention is a 20-min acute exercise using arm ergometer<br>|
| Experimental: SCI<br>Individuals with spinal cord injury | Behavioral: One bout of moderate-intensity sub-maximal aerobic exercise<br>* The intervention is a 20-min acute exercise using arm ergometer<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cardiac sympathetic function | Low frequency component of blood pressure variability in mmHg^2 | During baseline pre the 20-min acute exercise | 
| Cardiac parasympathetic function | High frequency component of heart rate variability in mm^2 | During baseline pre the 20-min acute exercise | 
| Cardiac sympathetic function | Low frequency component of blood pressure variability in mmHg^2 | During face-cooling test pre the 20-min acute exercise | 
| Cardiac parasympathetic function | High frequency component of heart rate variability in mm^2 | During face-cooling test pre the 20-min acute exercise | 
| Cardiac sympathetic function | Low frequency component of blood pressure variability in mmHg^2 | During head-up tilt test pre the 20-min acute exercise | 
| Cardiac parasympathetic function | High frequency component of heart rate variability in mm^2 | During head-up tilt test pre the 20-min acute exercise | 
| Cardiac sympathetic function | Low frequency component of blood pressure variability in mmHg^2 | During cognitive tests pre the 20-min acute exercise | 
| Cardiac parasympathetic function | High frequency component of heart rate variability in mm^2 | During cognitive tests pre the 20-min acute exercise | 
| Cardiac sympathetic function | Low frequency component of blood pressure variability in mmHg^2 | During baseline post the 20-min acute exercise | 
| Cardiac sympathetic function | Low frequency component of blood pressure variability in mmHg^2 | During face-cooling post the 20-min acute exercise | 
| Cardiac parasympathetic function | High frequency component of heart rate variability in mm^2 | During face-cooling post the 20-min acute exercise | 
| Cardiac sympathetic function | Low frequency component of blood pressure variability in mmHg^2 | During head-up tilt test post the 20-min acute exercise | 
| Cardiac parasympathetic function | High frequency component of heart rate variability in mm^2 | During head-up tilt test post the 20-min acute exercise | 
| Cardiac sympathetic function | Low frequency component of blood pressure variability in mmHg^2 | During cognitive tests post the 20-min acute exercise | 
| Cardiac parasympathetic function | High frequency component of heart rate variability in mm^2 | During cognitive tests post the 20-min acute exercise | 
| Cerebrovascular functions | Assessed by the middle and posterior cerebral artery velocity in centimeters per second | During baseline pre the 20-min acute exercise | 
| Cerebrovascular functions | Assessed by the middle and posterior cerebral artery velocity in centimeters per second | During the face-cooling test pre the 20-min acute exercise | 
| Cerebrovascular functions | Assessed by the middle and posterior cerebral artery velocity in centimeters per second | During the head-up tilt test pre the 20-min acute exercise | 
| Cerebrovascular functions | Assessed by the middle and posterior cerebral artery velocity in centimeters per second | During the cognitive tests pre the 20-min acute exercise | 
| Cerebrovascular functions | Assessed by the middle and posterior cerebral artery velocity in centimeters per second | During baseline post the 20-min acute exercise | 
| Cerebrovascular functions | Assessed by the middle and posterior cerebral artery velocity in centimeters per second | During the face-cooling test post the 20-min acute exercise | 
| Cerebrovascular functions | Assessed by the middle and posterior cerebral artery velocity in centimeters per second | During the head-up tilt test post the 20-min acute exercise | 
| Cerebrovascular functions | Assessed by the middle and posterior cerebral artery velocity in centimeters per second | During the cognitive tests post the 20-min acute exercise | 
| Cerebral oxygenation level | Cerebral oxygenated hemoglobin in unknown unit | Change from baseline to the cognitive tests pre the 20-min acute exercise | 
| Cerebral oxygenation level | Cerebral oxygenated hemoglobin in unknown unit | Change from baseline to the cognitive tests post the 20-min acute exercise | 
| Cognitive function | Reaction time in second | During baseline pre the 20-min acute exercise | 
| Cognitive function | Error made during the cognitive test in number | During baseline pre the 20-min acute exercise | 
| Cognitive function | Reaction time in second | During head-up tilt pre the 20-min acute exercise | 
| Cognitive function | Error made during the cognitive test in number | During head-up tilt pre the 20-min acute exercise | 
| Cognitive function | Reaction time in second | During baseline post the 20-min acute exercise | 
| Cognitive function | Error made during cognitive test in number | During baseline post the 20-min acute exercise | 
| Cognitive function | Reaction time in second | During head-up tilt post the 20-min acute exercise | 
| Cognitive function | Error made during the cognitive test in number | During head-up tilt post the 20-min acute exercise |