Corticospinal Tract Microstructure Correlates With Beta Oscillatory Activity in the Primary Motor Cortex After Stroke

Area of Science:

• Neuroscience
• Motor System Function
• Stroke Recovery Research

Background:

• Cortical beta oscillations are key indicators of motor system health.
• Stroke can alter these oscillations and impact motor function.
• The relationship between these brain function measures and structural changes post-stroke is not well understood.

Purpose of the Study:

• To investigate the association between brain function (beta oscillations) and brain structure (corticospinal tract integrity) in well-recovered stroke patients.
• To explore how microstructural changes in the corticospinal tract relate to EEG measures in motor areas.

Main Methods:

• Multimodal study of 18 well-recovered stroke patients using EEG and diffusion-weighted MRI.
• Assessed beta power at rest and movement-related beta desynchronization in primary motor cortex (M1), ventral premotor, and supplementary motor areas.
• Quantified microstructural integrity of corticospinal tracts (CST) using fractional anisotropy and related it to EEG measures.

Main Results:

• Stroke patients showed reduced ipsilesional CST fractional anisotropy compared to controls.
• A significant association was found between M1 beta power/desynchronization and fractional anisotropy of CST originating from M1.
• No similar structure-function relationships were observed for other motor areas or in controls.

Conclusions:

• Suggests a direct link between the microstructure of CST originating from M1 and beta oscillatory activity.
• These findings may help explain motor impairment in stroke patients.
• Highlights the potential of combining EEG and MRI for understanding stroke recovery.