With over 1.7 million people in the United States seeking medical attention for head injury each year, emergency clinicians are challenged daily to screen quickly for the small subset of patients who harbor a potentially lethal intracranial lesion while minimizing excessive cost, unnecessary diagnostic testing, radiation exposure, and admissions. Whether working at a small, rural hospital or a large inner-city public hospital, emergency clinicians play a critical role in the diagnosis and management of mild traumatic brain injury. This review assesses the burgeoning research in the field and reviews current clinical guidelines and decision rules on mild traumatic brain injury, addressing the concept of serial examinations to identify clinically significant intracranial injury, the approach to pediatric and elderly patients, and the management of patients who are on anticoagulants or antiplatelet agents or have bleeding disorders. The evidence on sports-related concussion and postconcussive syndrome is reviewed, and tools for assessments and discharge are included.
It’s 8 PM and you are just getting into the groove of your first in a series of several night shifts. After picking up your fourth head injury chart, you think to yourself, “Good grief, are we having a sale on head injury tonight?” Your patients are:
These are 4 cases of what appear to be minor injuries, although you know there is the chance that any of the patients may be harboring a neurosurgical lesion and that all 4 are at risk for sequelae. In your mind, you systematically go through the high-return components of the physical exam of a head-injured patient, the indications for neuroimaging in the ED, and the information needed at discharge to prepare the patients and their families for what might lie ahead. The medical student working with you is very impressed with the complexity of managing these cases, which he thought were so straightforward.
Minor head injury, mild traumatic brain injury (TBI, also known as MTBI), and concussion are terms that are often used interchangeably. Regardless of the variation in nomenclature, emergency clinicians can expect to see a number of patients each shift who have sustained some sort of blunt trauma to the head. The clinical approach to these patients varies widely, and, despite the availability of clinical guidelines, most patients will undergo computed tomography (CT) imaging, and the majority will be interpreted as normal. The challenge for emergency clinicians is to quickly screen for the small subset of patients who harbor a potentially lethal intracranial lesion while minimizing excessive costs, admissions, and unnecessary diagnostic testing. Emergency clinicians must accurately document a neurologic baseline for serial examinations and provide discharge instructions that educate patients and families about the potential sequelae of head injury no matter how minor the injury may appear to be.
Further challenges include the rapidly evolving milieu of head injury treatment in the sports arena, with all but 2 states having active or pending laws on return to play for youth sports and full elimination of any same-day return to play after concussive events.1 Furthermore, with up to 50% of nonactive military personnel seeking care outside of the Veterans Health Administration system,2 emergency clinicians can expect to provide care for the increasing numbers of military personnel returning to the United States with postconcussive symptoms. Called the “signature’”injury of the Iraq and Afghanistan Wars, military-related mild TBI has affected close to 200,000 soldiers to date,3,4 with up to 30% suffering continued postconcussive symptoms.5
Appraising the literature is very challenging due to the lack of uniformity—and often impassioned disagreement—regarding the definition of the terms used to describe these injuries. Moreover, studies often lack consistency in the timing of injury assessments, suffer from selection bias, and have conflicting outcome measures. The literature review was performed using PubMed and Ovid MEDLINE® searches for articles on TBI published between 1966 and 2012. Keywords included traumatic brain injury, concussion, head injury, MTBI, neuroimaging, postconcussive syndrome, sports, and second impact syndrome. The articles obtained from these searches provided content and background for further manual literature searches. Over 650 articles were reviewed, and 158 of these are included here for the reader’s reference.
Additionally, major published guidelines regarding mild TBI were evaluated. These included guidelines published by the Centers for Disease Control and Prevention (CDC), the Brain Trauma Foundation, the American College of Emergency Physicians (ACEP), the American Academy of Neurology, the American Academy of Pediatrics, the Advanced Trauma Life Support® (ATLS®) course, and the Eastern Association for the Surgery of Trauma. Website addresses for several guidelines are provided in Table 1.
Evidence-based medicine requires a critical appraisal of the literature based upon study methodology and number of subjects. Not all references are equally robust. The findings of a large, prospective, randomized, and blinded trial should carry more weight than a case report.
To help the reader judge the strength of each reference, pertinent information about the study will be included in bold type following the reference, where available. In addition, the most informative references cited in this paper, as determined by the authors, are noted by an asterisk (*) next to the number of the reference.
Why to Use
There are more than 8 million patients who present annually to emergency departments in the United States for evaluation of head trauma. The vast majority of these patients have minor head trauma that will not require specialized or neurosurgical treatment. At the same time, rates of CT imaging of the head more than doubled from 1995 to 2007.
When to Use
Daniel Runde, MD
The CCHR has been validated in multiple settings and has been consistently demonstrated to be 100% sensitive for detecting injuries that will require neurosurgery. Depending on practice environment, it may not be considered acceptable to miss any intracranial injuries, regardless of whether they would have required intervention.
Providers may want to consider applying the New Orleans Criteria for head trauma, as there has been at least 1 trial finding it to be more sensitive than the CCHR for detecting clinically significant intracranial injuries (99.4% vs 87.3%), though this comes at the price of markedly decreased specificity (5.6% vs 39.7%). Furthermore, there are other trials in which the CCHR was found to be more sensitive than the New Orleans Criteria for detecting clinically important brain injuries.
The validation study (Stiell 2005) included a convenience sample of 2702 patients aged ≥ 16 years, who presented to 9 Canadian emergency departments with blunt head trauma resulting in witnessed loss of consciousness, disorientation, or definite amnesia and a Glasglow Coma Scale score of 13 to 15. Within the sample, 8.5% (231/2707) of the patients had a clinically important brain injury, and 1.5% (41/2707) of the patients had an injury that required neurosurgical intervention. In the validation trial, the CCHR was 100% sensitive for both clinically important brain injuries and injuries that required neurosurgical intervention, and was 76.3% and 50.6% specific, respectively, for these injuries.
Subsequent studies have all found the CCHR to be 100% sensitive for identifying injuries that require neurosurgical intervention. Applying the CCHR would allow physicians to safely reduce head CT imaging by around 30% (range of 6%-40%, with most studies showing an estimated 30% reduction). In most studies, 7% to 10% of patients had positive CTs, considered “clinically important” brain injuries, but typically, < 2% of patients required neurosurgical intervention. The high-risk criteria have consis-tently shown 100% sensitivity at ruling out the latter group..
Ian Stiell, MD, MSc, FRCPC