Spinal epidural electrical stimulation for the recovery of motor function in lower limbs after spinal cord injury: A pilot study.

Study design: Single-arm prospective pilot study.

Purpose: To assess the safety and efficacy of sEES in the recovery of motor function after severe SCI in the Indian population and to evaluate the feasibility of a larger study.

Overview of literature: Standing and walking are highly desirable goals for persons with spinal cord injury (SCI). Activity-based locomotor training is the only available practice to enhance recovery at present. However, it does not yield significant outcomes in individuals with severe spinal cord injury. In recent years, Spinal epidural electrical stimulation (sEES) has been reported to produce rhythmic motor activity in limbs in a few case reports and also in clinical trials in animals and more recently, in a few human case reports.

Methods: We conducted a single-arm prospective pilot study at a tertiary care spine surgery center in five subjects with chronic spinal cord injury with an absence of useful power in lower limbs and satisfying the eligibility criteria. The Institute Ethics Committee and the Research Review Committee approved the study and it was registered with the Clinical Trials Registry of India.

Results: No intraoperative or early postoperative complications were noted in any of the subjects. Two subjects had wound complications at 1 and 3 months, respectively and were managed successfully. All of these participants were unable to stand, step, or walk without assistance before the recruitment. With epidural stimulation, four subjects gained better control of standing full weight bearing (without assistance). Four (80%) subjects were able to coordinate stepping on a treadmill and three (60%) were able to walk without knee braces with epidural stimulation. Objective functional outcome measures such as the Walking Index of spinal cord injury and Spinal Cord Independence Measure showed significant improvement (P = 0.004 and 0.002, respectively) with sEES. The trial could be implemented successfully, i.e. the desired recruitment could be achieved within a defined period, with procedural adherence and participant compliance.

Conclusions: sEES is a safe intervention. Locomotor training with sEES improves the motor abilities and functional recovery of persons with chronic SCI. A larger prospective study with more subjects needs to be done to draw a definite conclusion and seems to be feasible using the protocol, outcome measures, and recruitment strategy of the pilot study.