Structural Disconnections Caused by White Matter Hyperintensities in Post-Stroke Spatial Neglect.

Area of Science:

• Neuroscience
• Neurology
• Neuroimaging

Background:

• White matter hyperintensities (WMH) are common in cerebral small vessel disease and linked to cognitive deficits, including spatial neglect.
• Spatial neglect, a disorder of spatial attention, often follows right hemisphere brain damage.

Purpose of the Study:

• To investigate how WMH impact structural disconnections related to spatial neglect.
• To compare different measures of structural disconnection for predicting neglect severity.

Main Methods:

• Indirect quantification of the structural disconnectome induced by stroke lesions, WMH, or their combination.
• Comparison of voxel-wise, pairwise, tract-wise, and parcel-wise disconnection measures.
• Predictive modeling to assess the relationship between disconnections and acute neglect severity.

Main Results:

• WMH-derived disconnections alone did not correlate with neglect.
• Combined WMH and stroke lesion disconnections significantly contributed to neglect severity, affecting right frontal and subcortical regions (e.g., middle frontal gyrus, basal ganglia, thalamus, fronto-pontine tract).
• Voxel-wise disconnection data, particularly from stroke-based disconnections, best predicted neglect severity, explaining 42% of the variance.

Conclusions:

• Pre-stroke WMH alter white matter microstructure, contributing to post-stroke spatial attention deficits.
• These microstructural changes likely impair the integrity of brain attention networks, exacerbating neglect.
• Voxel-wise analysis of structural disconnections is a valuable tool for understanding and predicting post-stroke neglect.