Fatigue before and after mild traumatic brain injury:: Pre-post-injury comparisons in relation to Apolipoprotein E

Primary objective: To assess the incidence of fatigue for persons following a mild traumatic brain injury (MTBI) and to evaluate the relationship between fatigue and APOE genotype. As fatigue is often found to be influenced by anxiety, depression and sleep disturbance, these factors were also measured. Methods and procedures: Thirty-one persons who sustained a MTBI were drawn from a population-based longitudinal study. Each person who sustained a MTBI was matched by age, gender, education and APOE genotype with two non-head injury controls. Self-reported pre- and post-injury incidence of fatigue, anxiety, depression and sleep disturbance was compared within-group and between groups. Results: For the MTBI group, incidence of fatigue was almost twice as common post- than pre-injury, whereas there was no corresponding change in a non-injured control group. Within the MTBI-group, post-injury fatigue was particularly common for carriers of the APOE epsilon 4 allele. Conclusions: Fatigue is common sequela after a MTBI and especially pronounced for carriers of the APOE epsilon 4 allele.