Brain Oscillatory Modes as a Proxy of Stroke Recovery.

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Biophysics

Background:

• Stroke is a primary cause of long-term disability, highlighting the need for effective rehabilitation strategies.
• Understanding the neural mechanisms of stroke impairment and recovery is key to optimizing treatment outcomes.
• GABAergic system activity plays a role in neural inhibition and plasticity, influencing motor function.

Purpose of the Study:

• To investigate longitudinal changes in brain oscillatory modes related to GABAergic activity post-stroke.
• To determine the significance of these brain oscillations for residual upper-limb motor function and recovery.
• To explore potential electrophysiological biomarkers for stroke recovery.

Main Methods:

• Combined Transcranial Magnetic Stimulation (TMS) with scalp Electroencephalography (EEG) to analyze brain oscillations.
• Studied 66 stroke patients across acute, early, and late subacute recovery stages.
• Utilized parallel factor analysis (PARAFAC) for data-driven extraction of brain oscillatory modes.

Main Results:

• Brain oscillatory modes evolved significantly over longitudinal stroke stages (p < 0.05 Bonferroni corrected).
• A decrease in the alpha-mode, associated with GABAergic activity, was observed, particularly in recovering patients.
• This alpha-mode decrease correlated with improved upper-limb motor function recovery at the group level.

Conclusions:

• Longitudinal brain mode analysis offers insights into post-stroke neural reorganization.
• The observed alpha-mode decrease may indicate beneficial disinhibition, promoting plasticity and recovery.
• Monitoring inhibitory system activity could lead to personalized neuromodulation therapies and biomarkers for stroke recovery.