Clinical Outcome After Epidural Spinal Cord Stimulation in Patients With Severe Traumatic Brain Injury

Abstract

Introduction: Epidural spinal cord stimulation is a minimally invasive procedure with a growing list of indications. It has a good safety profile and analgesic effect, reduces the severity of spasticity, and activates various brain regions. The purpose of this study is to evaluate the clinical outcome of epidural spinal cord stimulation in patients with spastic syndrome and chronic disorders of consciousness resulting from severe traumatic brain injury (sTBI).Methods: Between 2021 and 2023, an epidural spinal cord stimulation test was performed in 34 patients with central paresis, severe hypertonia, and chronically altered consciousness following sTBI. The severity of spastic syndrome was assessed using a modified Ashworth scale. All patients underwent implantation of a cylindrical eight-contact test epidural electrode at C3-C5 cervical level, followed by neurostimulation and selection of individual modes. Tonic stimulation at a frequency of 60 Hz, "burst" mode, or a combination of the two was used.Results: Epidural spinal cord stimulation was administered for an average of 4 ± 1.5 days, with tonic stimulation mode applied in 15 (44.1%) patients, "burst" mode in 10 (29.4%), and a combination of two in nine (26.5%) patients. A reduction in spasticity with clinical improvement was observed in 21 patients (61.8%). The Ashworth scale scores for distal and proximal upper extremities decreased from 3 points to 2.5 points and from 3 points to 2 points, respectively. This was significant in the right upper limbs (p = 0.0152 distally and p = 0.0164 proximally). Significant improvements were also seen in the lower extremities. Active movements in paretic limbs increased or appeared in 12 patients (35.3%), while a heightened level of consciousness was observed in six patients (17.6%). Permanent neurostimulator implantation was performed in 12 patients (35.3%), with no reported surgical complications.Conclusion: Epidural spinal cord stimulation shows promise as an invasive rehabilitation method for patients with sTBI sequelae. Its use reduced the severity of spastic syndrome in over half of patients and increased active movements in paretic limbs in over a third. Notably, neuromodulation at the cervical level yielded pronounced effects on the upper extremities, both proximally and distally. Findings regarding consciousness level improvement are particularly intriguing but warrant further validation through randomized trials.