Electrical stimulation driving functional improvements and cortical changes in subjects with stroke

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Biomedical Engineering

Background:

• Stroke often results in impaired motor function, particularly in hand use.
• Neuromuscular electrical stimulation (NMES) is a potential therapeutic modality for motor recovery.
• Cortical excitability changes may underlie functional improvements after stroke rehabilitation.

Purpose of the Study:

• To investigate the effects of NMES on functional hand use and cortical activation in chronic stroke.
• To compare NMES treatment with a sham treatment in a controlled, double-blind study.
• To explore the relationship between sensory cortex stimulation and motor performance improvements.

Main Methods:

• A double-blind, controlled study involving 16 chronic stroke subjects receiving intensive NMES or sham treatment.
• Functional assessments included the Box and Block Test, Jebsen Taylor Hand Function Test, and isometric strength measurements.
• Functional magnetic resonance imaging (fMRI) was used to measure cortical activation changes during a finger-tracking task.

Main Results:

• NMES treatment significantly improved hand grasp and release, object manipulation, and self-rated hand function.
• Subjects receiving NMES showed increased cortical intensity in the ipsilateral somatosensory cortex.
• Sham treatment yielded improvements only in isometric finger extension strength, with further gains after crossover NMES.

Conclusions:

• NMES is effective in improving motor function and strength in chronic stroke survivors.
• NMES-induced somatosensory stimulation may enhance motor recovery by modulating cortical activity.
• This therapy shows promise for stimulating sensory pathways to facilitate improved motor control post-stroke.