The APOE ε4 allele is associated with increased frontally mediated neurobehavioral symptoms in amnestic MCI

Area of Science:

• Neuroscience
• Genetics
• Psychology

Background:

• The apolipoprotein E ε4 allele (APOE ε4) is a known risk factor for late-onset Alzheimer disease (AD).
• Frontal lobe dysfunction may be an early manifestation of APOE ε4 effects in AD.
• Neurobehavioral symptoms are crucial for understanding disease progression.

Purpose of the Study:

• To investigate the association between APOE ε4 carriage and neurobehavioral symptoms in amnestic mild cognitive impairment (aMCI) and AD patients.
• To determine if APOE ε4 influences frontal lobe integrity as measured by the Frontal Systems Behavior Scale (FrSBe).

Main Methods:

• Cognitive data and caregiver ratings on the FrSBe were collected from aMCI and AD patients stratified by APOE ε4 carrier status.
• Statistical analyses compared FrSBe scores between APOE ε4 carriers and noncarriers within each diagnostic group.

Main Results:

• APOE ε4 carriers in both aMCI and AD groups had poorer memory scores.
• In aMCI patients, APOE ε4 carriers exhibited significantly higher FrSBe Executive Dysfunction scores compared to noncarriers.
• No significant differences in current FrSBe scores were found between APOE ε4 carriers and noncarriers in the AD group.

Conclusions:

• APOE ε4-associated behavioral changes, specifically executive dysfunction, manifest during the aMCI stage.
• These behavioral changes may become less apparent or masked by the later stages of AD.