Behavioral and neurophysiological changes associated with a single session of bimanual task practice after stroke

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Motor Control

Background:

• Stroke survivors frequently experience impaired bimanual coordination and motor control.
• Understanding the neural mechanisms underlying bimanual performance is crucial for effective neurorehabilitation.

Purpose of the Study:

• To investigate the impact of bimanual task practice on motor performance, coordination, and corticospinal excitability (CSE) in chronic stroke survivors.
• To compare these effects with those observed in neurotypical controls.

Main Methods:

• Eleven chronic stroke survivors and ten controls completed 400 trials of a bimanual task.
• Movement time, errors, and bimanual coordination were assessed pre- and post-practice.
• Transcranial magnetic stimulation (TMS) measured CSE and transcallosal inhibition in motor cortices.

Main Results:

• Both groups improved movement speed without increased errors.
• Only controls showed significant improvements in bimanual coordination.
• Stroke survivors exhibited increased contralesional CSE, while controls showed bilateral increases.

Conclusions:

• A single bimanual practice session enhances motor speed but not coordination in stroke survivors.
• Contralesional motor cortex excitability is modulated by bimanual practice in stroke survivors.
• Findings suggest potential for targeted neurorehabilitation strategies to improve arm function post-stroke.