APOE genotype and neuropsychological outcome in mild-to-moderate traumatic brain injury: a pilot study

The influence of apolipoprotein (APOE) on neuropsychological outcome was investigated in 19 patients (25.79 ± 7.22 years) with mild-to-moderate traumatic brain injury and 14 matched healthy control subjects (27.43 ± 6.65 years).

Within- and between-group comparisons were employed.

APOE genotype was determined using the Polymerase Chain Reaction-Restriction Fragment Length Polymorphism method. Verbal learning and memory, speed of processing and executive function were assessed at 6 weeks and 6 months post-injury. A three-way [Group*Type*Time] ANOVA with repeated measures on the third factor was employed to determine the differences between groups and APOE genotype.

No Group*APOE Genotype*Time interaction was found for all neuropsychological measures, Auditory Verbal Learning Test (p = 0.484, η(2 )= 0.017), Trail Making Test-B (p = 0.454, η(2 )= 0.019), Controlled Oral Word Association (p = 0.107, η(2 )= 0.087) and Wisconsin Card Sorting Test-64 (p = 0.291, η(2 )= 0.038). The results of this pilot study support earlier findings that showed no relationship between APOE ε4 and poor recovery in the same population.

The preliminary findings suggest no clear APOE genotype influence on neuropsychological outcome in mild and moderate TBI patients. Large-scale studies with longer follow-up duration are warranted.