Neuroimaging and APOE genotype: a systematic qualitative review

Area of Science:

• Neuroscience
• Genetics
• Radiology

Background:

• Apolipoprotein E (APOE) is a key genetic risk factor for late-onset Alzheimer's disease (AD).
• APOE genotype is also implicated in cardiovascular disease, cognitive decline, and healthy aging.
• Understanding APOE's impact on brain structure and function is crucial for neurodegenerative disease research.

Purpose of the Study:

• To systematically review and assess the association between APOE genotype and cerebral structural/functional changes using brain imaging.
• To determine if these APOE-associated brain changes align with Alzheimer's disease progression stages (Braak stages).

Main Methods:

• Systematic literature review of studies investigating APOE genotype and brain imaging.
• Searched PubMed, PsycINFO, and Web of Science databases.
• Qualitative review of 64 identified articles.

Main Results:

• APOE epsilon4 allele is associated with hippocampal, amygdalar, and entorhinal cortex atrophy.
• Presence of APOE epsilon4 correlates with increased overall brain atrophy and white matter hyperintensity volumes.
• Observed alterations in cerebral blood flow and glucose metabolism patterns linked to APOE genotype.
• Effects may be more pronounced in specific age ranges, with APOE epsilon2 potentially indicating risk.

Conclusions:

• Structural brain changes are demonstrably associated with APOE genotype.
• These APOE-related brain changes appear more prominent in younger individuals undergoing aging.
• Findings suggest APOE's significant role in age-related brain alterations and neurodegeneration.