Severity of white matter hyperintensities: Lesion patterns, cognition, and microstructural changes.

Area of Science:

• Neurology
• Neuroimaging
• Gerontology

Background:

• White matter hyperintensity (WMH) is prevalent in aging populations.
• WMH is linked to cognitive decline and brain microstructure changes.

Purpose of the Study:

• To characterize WMH spatial patterns across severities.
• To investigate WMH impact on cognition and brain microstructure in non-demented elderly.

Main Methods:

• Qualitative (Fazekas scale) and quantitative assessment of WMH in 321 elderly individuals.
• MRI scanning with voxel- and atlas-based whole-brain white matter microstructure analysis.

Main Results:

• WMH severity negatively associated with working and episodic memory, starting at Fazekas 3.
• Significant white matter tract impairments observed from Fazekas 3, with brain-wide changes above Fazekas 4.
• Specific white matter tracts (superior cerebellar peduncle, left posterior thalamic radiation, middle cerebellar peduncle) linked to memory deficits.

Conclusions:

• Memory is primarily affected by WMH, influenced by tract-specific abnormalities.
• Fazekas scale 3 represents a critical stage for predicting future cognitive decline.