Results of epidural spinal cord stimulation in patients with consequences of severe traumatic brain injury

Epidural stimulation of the spinal cord is a mini-invasive procedure, the list of indications for which is increasing every year. Its advantages include relative safety, a small amount of surgical invasion, a low incidence of complications in combination with analgesic effect, the ability to reduce the severity of pathological muscle tone and an upward activating effect on various parts of the brain. Rehabilitation of patients with the consequences of severe traumatic brain injury is one of the core areas of work for the Research Institute of Rehabilitation of Prof. Pryanikova I. V., which made it possible to generalize and analyze the experience of using epidural stimulation in these patients. Aims: to evaluate the results of epidural stimulation in patients with spastic syndrome, chronic disorders of consciousness formed as a result of severe traumatic brain injury. Materials and methods: In 2021–2023, test epidural stimulation of the spinal cord was performed in 34 patients with the consequences of severe traumatic brain injury who were undergoing rehabilitation treatment at the Research Institute of Rehabilitation of the FNCC PP. The average age of patients was 34 ± 14 years, the ratio of men to women was 2.4:1. Central paresis with pronounced musculotonic syndrome was observed in all patients in the study group: in 22 patients — tetraparesis (64.7 %), in 9 — hemiparesis (26.5 %), and in 3 — spastic monoparesis (8.8 %). The severity of the spastic syndrome was assessed using a modified Ashworth scale. Chronic disorders of consciousness before epidural stimulation were detected in 20 patients (58.8 %): vegetative state — in 5 patients (14.7 %), the state of minimal consciousness «minus» — in 5 (14.7 %), the state of minimal consciousness «plus» — in 9 (26.5 %), exit from the state of minimal consciousness — in 1 (2.9 %). An eight — contact epidural test electrode was implanted in all patients at the cervical level (C3 — C5), followed by neurostimulation and selection of individual modes. The tonic stimulation mode, «Burst» mode or their combinations were used. Results: The duration of epidural stimulation in the study group was 4 ± 1.5 days. Tonic stimulation mode was used in 15 patients (44.1 %), «Burst» mode in 10 (29.4 %) and a combination of modes in 9 (26.5 %). A decrease in the severity of spastic syndrome against the background of ongoing stimulation was noted in 21 patients (61.8 %). The median score on the modified Ashworth scale for the distal upper extremities decreased from 3 points to 2.5 points, for the proximal upper extremities — from 3 points to 2 points. The most significant decrease in spasticity was observed in patients in the right upper limb (p = 0.0152 for distal sections and p = 0.0164 for proximal sections). There were no statistically significant differences in the lower extremities. An increase in volume or the appearance of active movements in paretic limbs was observed in 12 patients (35.3 %). An increase in the level of consciousness (in the form of increased contact with the patient, the appearance or increase in emotional reactions) — in 6 patients (17.6 %). According to the results of the course of stimulation, a permanent neurostimulator was implanted in 12 patients (35.3 %). Surgical complications were not detected in the study group. Conclusions: epidural stimulation is a promising method of invasive rehabilitation of patients with the consequences of traumatic brain injury, since its use has reduced the severity of spastic syndrome in more than half of patients, and achieved an increase in active movements in paretic limbs in more than a third of patients. When neuromodulation is performed at the cervical level, the most pronounced effect is observed in the upper extremities: both in their proximal and distal sections. The results obtained with respect to the level of consciousness are of particular interest, and need further confirmation through randomized trials.