The studies to date have unfortunately lacked power enough to address specific subpopulations of patients with mild TBI who may be at greater risk for delayed complications despite the initial negative head CT. These subpopulations include patients with bleeding disorders, patients on anticoagulant therapy, patients who have had previous neurosurgical procedures (e.g., ventriculoperitoneal shunt), and those with significant previous neurologic disease.

Central to ED management of all patients is delivery of good follow-up and aftercare instructions at discharge. These instructions should include both verbal and written information that is framed in an appropriate grade reading level. Up to 58% of patients with mild TBI will have some sequelae at 1 month post injury.²³ These symptoms, referred to as postconcussive symptoms, can be cognitive, affective, or somatic. Patient education regarding these symptoms provides important reassurance and may decrease symptom duration.

The research that has prompted this updated version of the clinical policy has helped to expand our knowledge and understanding of patients with mild TBI. There is a need for future collaboration within the neuroscience community on how best to define mild TBI, the role of diagnostic testing, and outcomes. Outcome studies must focus not only on identifying neuroimaging abnormalities but also on identifying risk for the development of postconcussive symptoms.

The clinical policy establishes the best evidence available for the specific critical questions addressed; however, of the five recommendations, there is only one level A recommendation. Regardless of the strength of evidence, a recommendation must always be placed in the context of a patient’s presentation and the setting where the patient is being treated.

Dr. Constantine and Dr. Jagoda are both members of ACEP’s Clinical Policies Committee, and both are practicing emergency physicians at Mount Sinai School of Medicine, New York, N.Y.

References

1. Rutland-Brown W, Langlois JA, Thomas KE, et al. Incidence of traumatic brain injury in the United States, 2003. J Head Trauma Rehabil. 2006;21:544-8.
2. Jagoda AS, Cantrill SV, Wears RL, et al. Clinical Policy: Neuroimaging and decisionmaking in adult mild traumatic brain injury in the acute setting. Ann Emerg Med. 2002;40:231-49.
3. Jagoda AS, Bazarian JJ, Bruns JJ Jr, et al. American College of Emergency Physicians and Centers for Disease Control and Prevention. Clinical policy: neuroimaging and decisionmaking in adult mild traumatic brain injury in the acute setting. Ann Emerg Med. 2008;52:714-48.
4. Kay T, Harrington D, Adams R, et al. Definition of mild traumatic brain injury. J Head Trauma Rehabil. 1993;8:86-7.
5. Centers for Disease Control and Prevention, National Center for Injury Prevention and Control. Report to Congress on Mild Traumatic Brain Injury in the United States: Steps to Prevent a Serious Public Health Problem. Atlanta, GA: Centers for Disease Control and Prevention; 2003:1-47.
6. Jennett B, Teasdale G, Galbraith S, et al. Severe head injuries in three countries. J Neurol Neurosurg Psychiatry. 1977;40:291-8.
7. Ibanez J, Arikan F, Pedraza S, et al. Reliability of clinical guidelines in the detection of patients at risk following mild head injury: results of a prospective study. J Neurosurg. 2004;100:825-34.
8. Smits M, Hunink MG, Nederkoorn PJ, et al. A history of loss of consciousness or post-traumatic amnesia in minor head injury: “condition sine qua non” or one of the risk factors? J Neurol Neurosurg Psychiatry. 2007;78:1359-64.
9. Stiell IG, Wells GA, Vandemheen K, et al. The Canadian CT Head Rule for patients with minor head injury. Lancet. 2001;357:1391-6.
10. Haydel MJ, Preston CA, Mills TJ, et al. Indications for computed tomography in patients with minor head injury. N Engl J Med. 2000;343:100-5.
11. Smits M, Dippel DW, de Haan GG, et al. External validation of the Canadian CT Head Rule and the New Orleans Criteria for CT scanning in patients with minor head injury. JAMA. 2005;294:1519-25.
12. Yates D, Chater N, Cooper P, et al, for the National Collaborative Centre for Acute Care. National Institute for Health and Clinical Excellence. Head Injury. Triage, assessment, investigation, and early management of head injury in infants, children, and adults; 2007. Available at: http://www.nice.org.uk/nicemedia/pdf/CG56NICEGuideline.pdf. Accessed Jan. 16, 2008.
13. Servadei F, Teasdale G, Merry G, for the Neurotraumatology Committee of the World Federation of Neurosurgical Societies. Defining acute mild head injury in adults: a proposal based on prognostic factors, diagnosis, and management. J Neurotrauma. 2001;18:657-64.
14. Doezema D, King J, Tandberg D, et al. Magnetic resonance imaging in mild head injury. Ann Emerg Med. 1991;20:1281-5.
15. Hofman PAM, Stapert SZ, van Kroonenburgh MJPG, et al. MR imaging, single-photon emission CT, and neurocognitive performance after mild traumatic brain injury. Am J Neuroradiol. 2001;22:441-9.
16. Hughes D, Jackson A, Mason D, et al. Abnormalities on magnetic resonance imaging seen acutely following mild traumatic brain injury: correlation with neuropsychological tests and delayed recovery. Neuroradiology. 2004;46:550-8.
17. Voller B, Benke T, Benedetto K, et al. Neuropsychological, MRI and EEG findings after very mild traumatic brain injury. Brain Injury. 1999;13:821-7.
18. Biberthaler P, Linsenmeier U, Pfeifer K-J, et al. Serum S-100B concentration provides additional information for the indication of computed tomography in patients after minor head injury. A prospective multicenter study. Shock. 2006;25:446-53.
19. Poli-de-Figueiredo LF, Biberthaler P, Filho CS, et al. Measurement of S-100B for risk classification of victims sustaining minor head injury—first pilot study in Brazil. Clinics. 2006;61:41-6.
20. Ingebrigtsen T, Romner B, Marup-Jensen S, et al. The clinical value of serum S-100 protein measurements in minor head injury: a Scandinavian multicentre study. Brain Injury. 2000;14:1047-55.
21. af Geijerstam JL, Oredsson S, Britton M. OCTOPUS Study Investigators. Medical outcome after immediate computed tomography or admission for observation in patients with mild head injury: randomised controlled trial. BMJ. 2006;333:465-571.
22. af Geijerstam JL, Britton M. Mild head injury: reliability of early head computed tomographic findings in triage for admission. Emerg Med J. 2005;22:103-7.
23. Bazarian JJ, Atabaki S. Predicting postconcussion syndrome after minor traumatic brain injury. Acad Emerg Med. 2001;8:788-95.