Controlling pre-movement sensorimotor rhythm can improve finger extension after stroke

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Biomedical Engineering

Background:

• Brain-computer interface (BCI) technology offers potential for motor function recovery post-stroke.
• Optimal BCI application for stroke rehabilitation remains under investigation.

Purpose of the Study:

• To investigate the effects of BCI-based training on sensorimotor rhythm (SMR) amplitude for robot-assisted finger extension in stroke survivors.
• To explore immediate and therapeutic effects of controlling pre-movement SMR on motor function.

Main Methods:

• Eight chronic stroke participants with hand impairment underwent a four-week, three-phase training protocol using the FINGER robotic exoskeleton.
• Phase 1: Identified person-specific SMR features correlated with finger extension intent.
• Phase 2: Participants learned to modulate SMR features via visual feedback without movement.
• Phase 3: Participants controlled SMR features and then attempted robot-assisted finger extension.

Main Results:

• Three of four participants achieving SMR control showed reduced reaction time and increased finger extension force after decreasing pre-movement SMR amplitude.
• Hand function (Box and Block Test) improved more in participants with SMR control (7.3 blocks) than without (3.5 blocks).
• Baseline hand function correlated with the degree of improvement.

Conclusions:

• Learning to control specific pre-movement SMR features may enhance finger extension in some stroke survivors.
• These findings suggest BCI training merits further investigation in stroke rehabilitation settings.