Recovery after mild traumatic brain injury : an integrative approach on understanding complaints, performance and functional outcome

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. The objective of this study was to determine the severity of fatigue six months after Mild Traumatic Brain Injury and its relation to outcome. Furthermore, we tested whether injury indices, such as Glasgow Coma Scale scores, are related to higher levels of fatigue. 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. Our results show that a total of 299 out of 618 eligible (response rate 52%) MTBI patients and 287 out of 482 eligible (response rate 62%) minorinjury 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. We conclude that one third of a large sample of MTBI patients experience 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. Introduction Every year 100-300/100,000 people sustain a Mild Traumatic Brain Injury (MTBI) (Cassidy 2004). Although most patients are able to return to their former level of functioning within three months, some patients report a variety of symptoms up to years after injury (Evans 1992, Levin 1987, Naalt van der 1999). Fatigue is one of the most frequently reported symptoms within the first month after injury as well as on the longer term, often experienced as being the most bothersome of all postconcussional sequealae (Ingebrigtsen 1998, King 1995, LaChapelle 1998, McCullagh 2001, Paniak 2002b, Ponsford 2000). In addition, there is evidence that feelings of debilitating tiredness continue to be a problem even when most symptoms have resolved (Kashluba 2004, Mickeviciene 2004). Research in other neurological populations like stroke and Multiple Sclerosis show that prolonged severe fatigue interferes with daily functioning and is associated with diminished quality of life (Chaudhuri 2004, Groot de 2003). To date, systematic and comparative studies on fatigue after MTBI are lacking, and as a result knowledge on the severity and nature of fatigue, its relation to outcome and causal mechanisms is limited. In most studies on outcome after MTBI, fatigue is addressed with single items within the framework of related subjects such as post-concussional symptoms (Haboubi 2001, Ingebrigtsen 1998, Kashluba 2004, Naalt van der 1999, Paniak 2002b) or depression (Cicerone 1997, Seel 2003). These studies do not differentiate