A Review of Functional Restoration From Spinal Cord Stimulation in Patients With Spinal Cord Injury

Abstract

Traumatic spinal cord injury often leads to loss of sensory, motor, and autonomic function below the level of injury. Recent advancements in spinal cord electrical stimulation (SCS) for spinal cord injury have provided potential avenues for restoration of neurologic function in affected patients. This review aims to assess the efficacy of spinal cord stimulation, both epidural (eSCS) and transcutaneous (tSCS), on the return of function in individuals with chronic spinal cord injury. The current literature on human clinical eSCS and tSCS for spinal cord injury was reviewed. Seventy-one relevant studies were included for review, specifically examining changes in volitional movement, changes in muscle activity or spasticity, or return of cardiovascular pulmonary, or genitourinary autonomic function. The total participant sample comprised of 327 patients with spinal cord injury, each evaluated using different stimulation protocols, some for sensorimotor function and others for various autonomic functions. One hundred eight of 127 patients saw improvement in sensorimotor function, 51 of 70 patients saw improvement in autonomic genitourinary function, 32 of 32 patients saw improvement in autonomic pulmonary function, and 32 of 36 patients saw improvement in autonomic cardiovascular function. Although this review highlights SCS as a promising therapeutic neuromodulatory technique to improve rehabilitation in patients with SCI, further mechanistic studies and stimulus parameter optimization are necessary before clinical translation.

Keywords: Electrical stimulation; Spinal cord injury; Spinal cord stimulation.

Fig. 1.

PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flow diagram of search for systematic review [2,7,19-88].

Fig. 2.

Range of stimulation locations.

Fig. 3.

Epidural (left) and transcutaneous (right) stimulation of the spinal cord. Lesion core is indicated by the orange oval. Epidural spinal cord stimulation electrode arrays are typically placed from T9–L1 or L1–S2. tSCS electrode arrays are typically placed from C2–6 or T11–12. Coronal views of electrodes included. Abdominal cavity not pictured.