Effects of Brain-Computer Interface-Functional Electrical Stimulation on Functional Recovery in Patients with Cervical Spinal Cord Injury: A Functional Near-Infrared-Based Study

Background Cervical spinal cord injury (CSCI) often manifests as quadriplegia. Brain‒computer interfaces (BCIs), which are currently popular research topics in rehabilitation, are capable of converting brain signals into external control signals to stimulate limbs and reestablish connections between the damaged central and peripheral nervous systems. The purpose of this study was to explore the efficacy of functional electrical stimulation (FES) from BCIs on upper limb function and cerebral cortex function in patients with CSCI. Methods We randomly divided 30 CSCI patients into an experimental group (EG) and a control group (CG), with 15 patients in each group. On the basis of routine rehabilitation, the EG received BCI-FES treatment, and the CG received FES treatment 3 times a week for a total of 4 weeks for 15 minutes each, and follow-up was conducted one month after the end of treatment. The American Spinal Cord Injury Association (ASIA) injury scale was used to select the key muscles of the upper extremity to evaluate muscle strength, and the key sensory points were selected for light touch and pain evaluation. The active range of motion was measured. The cross-sectional area (CSA) and the muscle tone of the extensor carpi radialis longus were measured. The SCIM-III is used to assess activities of daily living (ADL). Functional near-infrared spectroscopy (fNIRS) technology measures the functional connectivity (FC) of the resting brain network to reflect the functional state of the brain. The trial is registered with ChiCTR2400092020. Results CSCI patients were treated with BCI-FES, which led to significant improvements in muscle strength; the active range of motion of wrist palmar flexion and dorsiflexion; and the CSA of the ECRL, sensory function, and ADLs; these improvements were maintained for four weeks after the intervention ended. Furthermore, fNIRS revealed that BCI-FES training increased FC between different brain regions, revealing an impact on cortical plasticity in CSCI patients from the perspective of the central nervous system. Conclusions On the basis of routine rehabilitation, BCI-FES can effectively improve upper limb function and daily living activities in patients with CSCI and promote FC in the brain.