Epidural Stimulation and Resistance Training (REST-SCI) for Overground Locomotion After Spinal Cord Injury:...

Introduction: Implanted spinal cord epidural stimulation (SCES) is an emerging neuromodulation approach that increases the excitability of the central pattern generator [CPG] and enhances tonic and rhythmic motor patterns after spinal cord injury (SCI). We determine the effects of exoskeleton-assisted walking [EAW] + epidural stimulation [ES] + resistance training [RT] on volitional motor control as a primary outcome, as well as autonomic cardiovascular profile, body composition, and bladder function compared to EAW + delayed ES + noRT in persons with motor-complete SCI AIS A and B. Methods and Analysis: Twenty male and female participants [age 18-60 years] with traumatic motor-complete SCI [2 years or more post injury], and level of injury below C5 were randomized into either EAW + ES + RT or EAW + delayed-ES + no-RT groups for more than 12 months. Baseline, post-interventions 1 and 2 were conducted six months apart. Measurements included body composition assessment using anthropometry, dual x-ray absorptiometry, and magnetic resonance imaging prior to implantation to evaluate the extent of spinal cord damage, neurophysiologic assessments to record H-reflexes, overground ambulation and peak torque for both groups, and the Walking Index for Spinal Cord Injury Scale [WISCI 2]. Metabolic profile measurements included the resting metabolic rate, fasting biomarkers of HbA1c, lipid panels, total testosterone CRP, IL-6, TNF-α, plasma IGF-I, IGFBP-3, and then a glucose tolerance test. Finally, urodynamic testing was conducted to assess functional bladder improvement due to ES. Results: The restoration of locomotion with ES and EAW may result in a reduction in psychosocial, cardiovascular, and metabolic bladder parameters and socioeconomic burden. The addition of the resistance training paradigm may further augment the outcomes of ES on motor function in persons with SCI. Conclusions: Percutaneous SCES appears to be a feasible and safe rehabilitation approach for the restoration of motor function in persons with SCI. The procedure may be successfully implemented with other task-specific training similar to EAW and resistance training.