# Effects of visually induced motor imagery-based brain-computer interface training on motor function in patients with incomplete spinal cord injury: a small-sample exploratory trial

## TL;DR

This study explores how brain-computer interface training using motor imagery helps improve motor function in patients with incomplete spinal cord injuries.

## Contribution

The study introduces visually induced motor imagery-based BCI training as a novel rehabilitation strategy for incomplete spinal cord injury recovery.

## Key findings

- The experimental group showed greater improvement in brain engagement and motor scores compared to the control group.
- BCI training enhanced brain network connections and modulated cortical activity in motor-related regions.
- Both groups demonstrated significant clinical improvements in balance and functional ambulation.

## Abstract

This study aimed to investigate the effects of visually induced motor imagery (MI)-based brain-computer interface (BCI) training on the neurological recovery of patients with incomplete spinal cord injury (iSCI), and to preliminarily explore the underlying neural mechanisms.

A single-center, single-blind, small-sample exploratory trial was conducted, enrolling 11 patients with iSCI who were randomly assigned to either the experimental or control group. The experimental group received visually induced BCI training based on a MI paradigm, while the control group received visually guided MI training combined with passive lower limb movements. Both groups underwent interventions five times per week for 4 weeks. Clinical assessments, including the American Spinal Injury Association (ASIA) motor/sensory scores, Berg Balance Scale (BBS), and Functional Ambulation Category (FAC), were conducted before and after the intervention. Simultaneously, electroencephalography (EEG) data were collected to analyze brain engagement, functional connectivity, and time-frequency characteristics, aiming to elucidate the neuromodulatory effects of BCI training.

After the intervention, both groups showed significant improvements in brain engagement, with the experimental group demonstrating greater enhancement. Compared with before rehabilitation training, the levels of θ waves in both groups significantly increased after rehabilitation training, while the levels of β waves significantly decreased (p < 0.05), especially in areas related to exercise planning and sensory integration. The connections between brain regions in the delta and theta frequency bands were significantly enhanced, and the density of brain network connections was significantly increased (p < 0.05) particularly in regions associated with motor planning and sensory integration. Clinically, all functional scores improved significantly in both groups (p < 0.05), and the experimental group showed superior improvement in ASIA motor and sensory scores, BBS, and FAC levels compared to the control group (p < 0.05).

Visually induced MI-based BCI training effectively promotes neurological recovery in patients with iSCI, as evidenced by enhanced brain network reorganization, modulation of cortical excitability, and activation of motor-related neural rhythms. This study confirms the feasibility and safety of this intervention strategy and offers a novel direction for iSCI rehabilitation.

Chinese Clinical Trial Registry (ChiCTR), identifier: ChiCTR2400095010.