Increased regional white matter hyperintensity volume in objectively-defined subtle cognitive decline and mild...

Area of Science:

• Neuroimaging
• Neurology
• Cognitive Science

Background:

• White matter hyperintensities (WMH) are markers of small vessel cerebrovascular disease.
• WMH are associated with increased risk for mild cognitive impairment (MCI) and Alzheimer's disease (AD).
• The pattern and extent of WMH in pre-MCI stages, like objectively-defined subtle cognitive decline (Obj-SCD), are less understood.

Purpose of the Study:

• To investigate the regional and volumetric differences in WMH among cognitively unimpaired (CU), Obj-SCD, and MCI groups.
• To determine if Obj-SCD exhibits distinct WMH patterns compared to CU and MCI populations.
• To explore the utility of Obj-SCD criteria in identifying biologically based cognitive changes.

Main Methods:

• Utilized data from 559 participants in the Alzheimer's Disease Neuroimaging Initiative (ADNI).
• Participants included 170 CU, 83 Obj-SCD, and 306 MCI, all free of clinical dementia or stroke.
• Neuropsychological testing and MRI data were analyzed using ANCOVA models, adjusting for age, sex, and APOE ɛ4 status.

Main Results:

• Obj-SCD group showed greater temporal, occipital, and frontal WMH compared to the CU group.
• The MCI group exhibited higher WMH volume across all regions compared to the CU group (p < 0.01).
• No significant differences in WMH volume were found between the Obj-SCD and MCI groups (p > 0.05).

Conclusions:

• Obj-SCD is associated with increased WMH in specific brain regions, mirroring patterns seen in MCI.
• These findings support the use of Obj-SCD criteria to identify individuals with subtle, biologically based cognitive changes.
• The study highlights the potential of imaging biomarkers in detecting early stages of neurodegenerative processes.