Description of the condition
Traumatic brain injury (TBI) involves an alteration of mental functions following trauma to the head (Vos 2002; Cassidy 2004b). It is estimated that approximately 90% of TBIs are classified as 'mild' using the standard definition of the American Congress of Rehabilitation Medicine published in 1993 (Ruff 2009; Mild 1993). According to this definition, a mild TBI (mTBI) is defined by the presence of a head injury resulting from blunt head trauma and/or deceleration or acceleration forces, a Glasgow coma scale of 13 to 15 and at least one of the four following criteria (Mild 1993):
Any period of observed or self-reported loss of consciousness lasting 30 minutes or less,
Any loss of memory for events immediately before or after the trauma,
Any alteration in mental state at the time of the accident (e.g. feeling dazed, disoriented or confused),
Observed signs of other neurological or neuropsychological dysfunction that may or may not be transitory,
and the absence of the following criteria:
Post-traumatic amnesia greater than 24 hours,
Glasgow Coma Scale score of less than 13, more than 30 minutes following the trauma.
Mild TBI is a common reason for consulting an emergency department. A systematic review of the literature, conducted by the World Health Organisation (WHO), reported approximately 600 cases of mTBI per 100,000 adults in North America (Bazarian 2005; Cassidy 2004a; Cassidy 2004b; Jager 2000; Sosin 1996). This incidence is higher for young adults and athletes showing rates varying between 0.4 cases per 1000 participants-games for football, and 17 cases per 1000 participants-games for ice hockey (Boden 1998; Buckley 1988; Cassidy 2004b; Jorgensen 1986; Powell 1999; Roberts 1999; Tegner 1996). The WHO's reported incidence of mTBI in children varies from 50 to 100 cases per 100,000 children-years depending on age (Cassidy 2004b; Durkin 1998; Rivara 1982; Rivara 1984). A review by the American Academy of Paediatrics (AAP) reported in 2001 that TBI was responsible for 600,000 visits to the emergency department, 95,000 hospitalisations and costs exceeding USD 1 billion per year in the United States of America (Schutzman 2001). Also, TBI was the leading cause of death among children.
There are more than 100 published studies evaluating neurological complications due to mTBI (Carroll 2004; Pertab 2009). These studies report that between 55% and 90% of patients suffering from an mTBI will show variable post-concussion symptoms during the week following the incident (Carroll 2004; King 1996). These symptoms can be of a cognitive (memory loss, attention deficit, etc), somatic (headache, fatigue, nausea) or psychological nature (depression, irritability, etc.). For example, it has been reported that the median duration of headache following an mTBI is one week (Lowdon 1989).
Most studies suggest that the long-term evolution of mTBI is excellent with complete resolution of symptoms within three months (Carroll 2004; King 1996; King 1999). However, some conflicting studies report that 40% of patients suffering mTBI will have persistent symptoms at one month post injury (Ingebrigtsen 1998) and as many as 15% remain symptomatic at one year post injury (Alexander 1995; Reitan 1999).
A paediatric systematic review reported that most children aged younger than 16 with symptoms of mTBI have complete resolution of these symptoms within 2 to 12 weeks (Carroll 2004). However, children sustaining mTBI are at higher risk of developing attention deficit hyperactivity disorder (McGinn 2000). Also, studies have suggested that mTBI increases the risk of behavioural problems for young children (Anderson 2009; Beauchamp 2011). This is related to recent findings in neuropsychology suggesting that the immature brain of young children is more sensitive to trauma during some critical phase of development (Anderson 2005). There are also important financial consequences of paediatric TBI. For example, mTBI children represent 90% of the hospitalisation days among all children admitted for all levels of TBI (Kraus 1987).
Description of the intervention
Most patients requiring medical resources secondary to mTBI are initially evaluated at the emergency department. Once proper evaluation is completed, treatments offered for patients suffering from mTBI are driven mainly by the symptoms. These include medications given in the acute phase to decrease pain, nausea or dehydration. There are very few studies evaluating potential treatment for patients with mTBI. A systematic review was conducted by the WHO to evaluate the prevalence, outcomes and potential treatments for mTBI (Borg 2004). Only 16 studies describing potential treatment for mTBI were included and none of these evaluated activity restriction or rest. More recently, a literature review evaluated return-to-play guidelines for children (Purcell 2009). The main conclusion was the paucity of studies regarding management of concussion among children.
Review articles and guidelines discussing the management of mTBI generally recommend activity restriction (Cushman 2001; McCrory 2009; Standaert 2007; Willer 2006). For example, in 2009 a consensus statement from the 3rd international conference on concussion in sport was published in multiple journals (McCrory 2009). The authors reported "the cornerstone of concussion management is physical and cognitive rest until symptoms resolve". A survey reported in 2001 that 40% of neurologists in Europe recommend full bed rest after mTBI (de Kruijk 2001). However, the recommendation regarding activity restriction lacks a scientific evidence base. This was highlighted by a recent study showing poor rigour in the development of guidelines regarding mTBI (Berrigan 2011). Also, a randomised controlled trial published in 2002 suggested that for adults who have sustained mTBI, full bed rest had no impact on symptom resolution (de Kruijk 2002).
Why it is important to do this review
Among people with TBI, 90% have mTBI. Therefore the financial and societal impact of mTBI is of great consequence. While most people with TBI have an excellent prognosis after three months, many present persistent symptoms at one week following injury (Carroll 2004; King 1996; Lowdon 1989). It is therefore imperative to identify treatment modalities capable of improving short-term and medium-term outcomes for people who have sustained mTBI.
In September 2011, there were 17 systematic reviews evaluating a treatment for TBI in The Cochrane Library. However, the primary outcomes reported in these studies, such as death or the Glasgow Outcome Scale, are only relevant for severe or moderate TBI. To our knowledge, there is no systematic review of the potential treatments to decrease short-term symptoms for patients with mTBI. Nor is there evaluation of the potential impact of activity restriction or rest for these patients.