Classification and characterization of periventricular and deep white matter hyperintensities on MRI: A study in...

Area of Science:

• Neuroimaging
• Gerontology
• Cerebrovascular Health

Background:

• White matter hyperintensities (WMH) are categorized as periventricular (PWMH) and deep (DWMH).
• These WMH subtypes are linked to distinct cognitive, microstructural, and clinical outcomes.
• Current anatomical definitions for PWMH and DWMH vary across studies, impacting result comparability.

Purpose of the Study:

• To compare four criteria for defining PWMH and DWMH in healthy older adults, assessing volume differences.
• To investigate associations between PWMH and DWMH with cognition, microstructure, and cardiovascular risk factors.
• To analyze how different classification criteria influence these associations.

Main Methods:

• Comparative analysis of four WMH classification criteria in a cohort of healthy older adults (mean age 69.58 ± 5.33).
• Quantification of estimated volumes for PWMH and DWMH based on different criteria.
• Exploration of associations between WMH subtypes and cognitive function, microstructural integrity (fractional anisotropy), and cardiovascular risk factors (mean arterial pressure, body mass index).

Main Results:

• The classification criterion for PWMH and DWMH is unlikely to be a major obstacle for inter-study comparisons.
• Increased PWMH load correlates with cognitive decline, higher mean arterial pressure, and older age.
• Higher DWMH load is associated with increased body mass index.
• PWMH exhibit lower fractional anisotropy than DWMH, with DWMH showing more heterogeneous microstructure.

Conclusions:

• PWMH and DWMH represent distinct pathological entities.
• The distinction between PWMH and DWMH provides valuable information for understanding healthy and pathological aging processes.
• WMH classification, despite definitional variations, aids in characterizing age-related brain changes and associated risks.