The safety of epidural spinal cord stimulation to restore function after spinal cord injury: post-surgical complications and incidence of cardiovascular events

Introduction: Epidural spinal cord stimulation (eSCS) improves volitional motor and autonomic function after spinal cord injury (SCI). While eSCS has an established history of safety for chronic pain patients, it remains unclear if eSCS in the SCI population presents the same risk profile. Objective: This study aims to assess safety, battery usage, and autonomic monitoring data for the first 14 participants enrolled in the E-STAND clinical trial in order to better characterize the safety of eSCS in individuals with chronic SCI. Methods: Monthly follow-up visits assessed surgical and medical device related safety outcomes as well as stimulation usage. Beat-by-beat blood pressure (BP) and continuous electrocardiogram data were collected during head-up tilt-table testing with and without eSCS. Results: Fourteen participants with motorcomplete SCI were enrolled, aged 38 ± 10 years and time since injury 7 ± 5 years. There were no surgical complications but one device malfunction 4 months post-implantation. Stimulation was applied for up to 23 hours a day, across a broad range of parameters: frequency (18-700 Hz), pulse width (100-600 μs) and amplitude (0.4-17 mA), with no adverse events reported. Tilt-table testing with eSCS demonstrated no significant increases in the incidence of elevated systolic BP ( >150 mmHg) or a greater frequency of arrhythmias. Conclusion: Despite the prevalence of significant comorbidities and the wide variety of stimulation parameters tested, eSCS to restore autonomic and volitional motor function following SCI appears to have a similar safety profile as when used to treat chronic pain.