Neurorehabilitation of post-stroke patients using a noninvasive spinal neuroprosthesis

Abstract

Neurorehabilitation of post-stroke patients with motor impairments is a significant and yet unresolved issue in restorative medicine. We propose a novel approach to rehabilitating such patients using transcutaneous electrical spinal cord stimulation (scTS), which targets the neural locomotor networks of the lumbar enlargement of the human spinal cord [1]. The Spinal Neuroprosthesis device was developed to control stimulation, providing noninvasive and phase-dependent activation of motoneuronal pools of flexors and extensors during a certain phase of the stepping cycle, combined with the activation of neuronal locomotor networks [2]. The aim of this study is to assess the efficacy of Spinal Neuroprosthesis in regulating locomotor functions among post-stroke patients with motor disorders. The study is designed to provide an objective evaluation of the medical device’s effectiveness. The study was conducted at the Russian Research Institute of Neurosurgery named after Prof. A.L. Polenov. The study enrolled 20 patients who had been experiencing severe motor disorders of the lower extremities in the form of hemiparesis. The duration of stroke among these patients ranged from 3 to 12 months. They were divided into two groups: control and experimental. The control group underwent sham (scTS-) stimulation during a motor rehabilitation session, while the experimental group received real scTS, establishing the difference between the groups. The rehabilitation program comprised 15 sessions of stimulation to the spinal cord. The treatment protocol comprised an initial evaluation of patients’ neurological and rehabilitation status and an investigation of spatial-temporal and kinematic parameters of walking. Subsequently, patients participated in rehabilitation sessions, which entailed walking on the treadmill and over-ground stepping with scTS. Finally, patients underwent a follow-up examination that included a re-evaluation of their neurological and rehabilitation status, as well as an investigation of spatial-temporal and kinematic parameters of walking. At the beginning of the program, the distance traveled by patients in the control and experimental groups during a six-minute walk test, according to the study results, did not differ significantly. However, following the treatment, patients in the experimental group demonstrated a substantially lengthier distance covered during the 6-minute test than the control group. Both groups of patients in the 10-meter walk test demonstrated an increase in distance walking speed, although the patients in the experimental group had a greater increase in speed compared to those in the control group. These improvements were more pronounced in patients from the experimental group. The results from neurological scales indicated an increase in muscular strength, improvement in balance functions, and an increase in functional independence in both groups. The findings provide evidence that the Spinal Neuroprosthesis effectively regulates stepping movements and restores locomotor function in patients post-stroke. Clinically significant improvements are observed within two weeks of neuroprosthesis use. Additionally, training increases patients’ exercise tolerance while walking, speed of movement, and functional independence.