Recovery from mild traumatic brain injury: a focus on fatigue.

BACKGROUND: Fatigue is one of the most frequently reported symptoms after Mild Traumatic Brain Injury (MTBI). To date, systematic and comparative studies on fatigue after MTBI are scarce, and knowledge on causal mechanisms is lacking. OBJECTIVES: To determine the severity of fatigue six months after MTBI and its relation to outcome. Furthermore, to test whether injury indices, such as Glasgow Coma Scale scores, are related to higher levels of fatigue. METHODS: Postal questionnaires were sent to a consecutive group of patients with an MTBI and a minor-injury control group, aged 18-60, six months after injury. Fatigue severity was measured with the Checklist Individual Strength. Postconcussional symptoms and limitations in daily functioning were assessed using the Rivermead Post Concussion Questionnaire and the SF-36. RESULTS: A total of 299 out of 618 eligible (response rate 52%) MTBI patients and 287 out of 482 eligible (response rate 60%) minor-injury patients returned the questionnaire. Ninety-five MTBI patients (32%) and 35 control patients (12%) were severely fatigued. Severe fatigue was highly associated with the experience of other symptoms, limitations in physical and social functioning, and fatigue related problems like reduced activity. Of various trauma severity indices, nausea and headache experienced on the ED were significantly related to higher levels of fatigue at six months. CONCLUSIONS: In conclusion, one third of a large sample of MTBI patients experiences severe fatigue six months after injury, and this experience is associated with limitations in daily functioning. Our finding that acute symptoms and mechanism of injury rather than injury severity indices appear to be related to higher levels of fatigue warrants further investigation