APOE-ε4 Is Associated With Reduced Verbal Memory Performance and Higher Emotional, Cognitive, and Everyday Executive
Torgeir Hellstrøm1, Nada Andelic1,2, Øyvor Øistensen Holthe1
1Department of Physical Medicine and Rehabilitation, Oslo University Hospital, Oslo, Norway.
Background:
Substantial variance exists in outcomes after mild traumatic brain injury (MTBI), and these differences are not fully explained by injury characteristics or severity. Genetic factors are likely to play a role in this variance.
Objectives:
The aim of this study was to examine associations between the apolipoprotein (APOE)-ε4 allele and memory measures at two months post-MTBI and to evaluate whether subjective cognitive and affective symptoms were associated with APOE-ε4 status. Based on previous research, it was hypothesized that APOE-ε4 carriers would show poorer verbal memory performance compared to APOE-ε4 non-carriers.
Methods:
Neuropsychological data at two months post-injury and blood samples that could be used to assess APOE genotype were available for 134 patients with MTBI (mean age 39.2 years, 62% males, 37% APOE-ε4 carriers). All patients underwent computed tomography at hospital admission and magnetic resonance imaging four weeks post-injury.
Results:
The APOE-ε4 + status was associated with decreased immediate memory recall (p = 0.036; β = -0.10, 95% CI [-0.19, -0.01]). Emotional, cognitive, and everyday executive function symptoms at two months post-injury were significantly higher in APOE-ε4 carriers compared to non-carriers.
Conclusion:
The APOE-ε4+ allele has a negative effect on verbal memory and symptom burden two months after MTBI.
