White matter hyperintensity patterns: associations with comorbidities, amyloid, and cognition

Area of Science:

• Neuroimaging
• Neuropathology
• Gerontology

Background:

• White matter hyperintensities (WMHs) are typically measured globally, but their spatial distribution may reveal distinct risk factors and clinical correlations.
• Understanding the regional patterns of WMHs is crucial for identifying underlying causes and potential therapeutic targets.

Purpose of the Study:

• To investigate the spatial heterogeneity of white matter hyperintensities (WMHs).
• To explore the associations of WMH patterns with comorbidities, Alzheimer's disease (AD) risk factors, and cognitive function.

Main Methods:

• 171 cognitively unimpaired and 51 mildly cognitively impaired individuals underwent amyloid PET and FLAIR-weighted imaging.
• White matter was segmented into 38 parcels to calculate WMH volume per region.
• Correlated principal component analysis identified WMH patterns, and regression models assessed associations with health factors and cognition.

Main Results:

• Four main WMH patterns were identified: posterior, periventricular, deep white matter, and subcortical gray matter.
• Hypertension was linked to most patterns in cognitively unimpaired individuals.
• In MCI individuals and the combined sample, specific WMH patterns correlated with renal disorders, sleep disorders, endocrine/metabolic disorders, and increased amyloid, impacting episodic memory when amyloid was present.

Conclusions:

• Regional WMH patterns provide valuable insights into underlying risk factors and neuropathology.
• Periventricular and deep gray matter WMH patterns may have significant cognitive implications, especially in the presence of amyloid pathology.