Geometric microstructural damage of white matter with functional compensation in post-stroke

Area of Science:

• Neuroscience
• Medical Imaging
• Biophysics

Background:

• Subcortical ischemic stroke often causes microstructural changes in white matter fiber orientation around the infarct.
• Understanding these changes is crucial for diagnosing and managing cognitive impairment after stroke.

Purpose of the Study:

• To determine white matter fiber orientation changes in post-stroke patients with and without cognitive impairment (PSCI, NPSCI).
• To investigate the impact of peri-infarct white matter damage on cerebral regions' morphology and functional connectivity.

Main Methods:

• Director Field Analysis (DFA) was used to study white matter fiber orientation in PSCI (n=23), NPSCI (n=17), and cognitively normal (CN, n=29) individuals.
• Seed-based functional connectivity analysis and machine learning models were employed.

Main Results:

• PSCI patients showed extensive white matter fiber orientation abnormalities compared to NPSCI and CN groups.
• NPSCI patients exhibited increased white matter fiber bending and twisting in the internal capsule versus CN.
• Peri-infarct white matter deficits significantly impacted functional connectivity and correlated with cognitive scores, predicting cognitive status.

Conclusions:

• Post-stroke patients exhibit pathological damage in peri-infarct white matter fiber orientation.
• This damage can lead to abnormal functional connectivity in connected cerebral regions.
• Degeneration of white matter fibers and altered functional connectivity may underlie cognitive impairment post-stroke.