Cardiovascular and autonomic responses to transcutaneous spinal cord stimulation combined with activity-based therapy after chronic spinal cord injury: An exploratory study from the MACHINE trial
This study indicates that cardiovascular responses to treadmill training with spinal cord stimulation are measurable but vary greatly among individuals, necessitating further research.
Where it sits
this study against the rest of the ss-31 corpusSummary and findings
This study measured cardiovascular and autonomic responses to body weight-supported treadmill training combined with active or sham transcutaneous spinal cord stimulation in eight adults with chronic, motor-complete spinal cord injury. Participants underwent 12 weeks of intervention, with some showing changes in cardiovascular indices. However, the responses were heterogeneous and overlapped with the sham group.
Abstract
<h4>Objective</h4> To describe cardiovascular and autonomic responses to body weight-supported treadmill training (BWSTT) combined with active or sham transcutaneous spinal cord stimulation (TSCS) in individuals with chronic, motor-complete spinal cord injury (SCI). <h4>Design and setting</h4> Exploratory case series from randomized, sham-controlled clinical trial in a tertiary Rehabilitation Centre in Vancouver, Canada. <h4>Participants</h4> Eight adults with chronic (≥1 year post-injury) traumatic, motor-complete (American Spinal Injury Association Impairment Scale A-B) SCI at or above T6 <h4>Interventions</h4> Participants were randomized to 12 weeks of BWSTT plus lumbosacral TSCS or BWSTT plus sham stimulation, delivered 3 sessions/week. TSCS was delivered at T11-L1 using 30 Hz stimulation with a 10 kHz carrier frequency. Five participants completed the intervention, and four completed full cardiovascular testing (TSCS n=2; sham n=2). <h4>Outcome measures</h4> Ambulatory blood pressure (BP) monitoring, participant-reported symptoms of AD and OH (via ADFSCI questionnaire), BP variability, orthostatic hemodynamics, echocardiography, electrocardiography (ECG)- and heart rate variability (HRV)-derived indices, and baroreflex function. <h4>Results</h4> Among complete cases, several cardiovascular indices changed over time, including reduced daytime hypotensive burden in TSCS participants, preserved nocturnal dipping, and small changes in stroke volume and ECG-derived variability indices; however, responses were heterogeneous and overlapped with Sham. Both TSCS and Sham participants showed reduced autonomic symptom scores, while low-frequency blood pressure variability responses during orthostatic stress were heterogeneous and did not indicate a pattern that was specific to a cohort. <h4>Conclusion</h4> Although preliminary, this exploratory complete-case analysis suggests that cardiovascular responses to BWSTT with active or sham TSCS are measurable but highly individualized after chronic motor-complete SCI. Given the small sample and overlapping Sham responses, findings are exploratory and larger trials are needed to determine whether TSCS augments cardiovascular autonomic adaptations to locomotor training.