Brain Functional Changes in Stroke Following Rehabilitation Using Brain-Computer Interface-Assisted Motor Imagery...

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Biomedical Engineering

Background:

• Motor imagery-based brain-computer interfaces (MI-BCI) and transcranial direct current stimulation (tDCS) are known to improve motor function post-stroke.
• The combined effects of MI-BCI and tDCS on post-stroke motor rehabilitation remain largely unexplored.
• Understanding brain functional changes is crucial for optimizing stroke recovery strategies.

Purpose of the Study:

• To investigate the impact of a combined MI-BCI and tDCS intervention on brain functional activity and connectivity in chronic subcortical stroke patients.
• To compare the neuroimaging and clinical outcomes between a group receiving MI-BCI with tDCS and a group receiving MI-BCI only.

Main Methods:

• Nineteen chronic subcortical stroke patients were randomized into two groups: MI-BCI with real/sham tDCS and MI-BCI only.
• Intervention involved 10 sessions of 20-minute tDCS followed by 1-hour MI-BCI training with robotic feedback over two weeks.
• Resting-state fMRI data were analyzed pre- and post-intervention to assess Amplitude of Low-Frequency Fluctuation (ALFF), Regional Homogeneity (ReHo), and Functional Connectivity (FC).

Main Results:

• Baseline: Stroke patients exhibited altered ALFF/ReHo in the somatomotor network (SMN) and default mode network (DMN) compared to controls.
• MI-BCI only group: Showed increased ALFF in the contralesional SMN and decreased ALFF/ReHo in the posterior DMN post-intervention.
• MI-BCI + tDCS group: No significant changes in ALFF, ReHo, or FC were observed post-intervention. Both groups improved motor function (Fugl-Meyer Assessment) without significant group differences.

Conclusions:

• The MI-BCI only intervention promoted brain functional re-normalization and network-specific compensation, unlike the combined MI-BCI + tDCS approach.
• Despite similar motor function improvements, the combined MI-BCI and tDCS strategy did not yield the expected neuroimaging benefits and may even have opposing effects on brain reorganization.
• Further research is needed to refine the integration of MI-BCI and tDCS to enhance their efficacy in stroke motor rehabilitation.