The inclusion criteria for application of the recommendations of this clinical policy are:

• Nonpenetrating trauma to the head;
• Presentation to the ED within 24 hours of injury;
• A GCS score of 14 or 15 on initial evaluation in the ED; and
• Age 16 years or older.

The exclusion criteria are:

• Penetrating trauma;
• Patients with multisystem trauma;
• GCS score less than 14 on initial evaluation in the ED; and
• Age younger than 16 years.

Neither loss of consciousness nor posttraumatic amnesia was used as an inclusion or exclusion criterion. Since the publication of the first edition of this clinical policy in 2002, two well-designed studies have demonstrated that neither loss of consciousness nor posttraumatic amnesia is sufficiently sensitive to identify patients at risk for intracranial injury.^7,8 After a review of these studies, the panel decided to eliminate these factors as criteria for the 2008 clinical policy.

The questions addressed in this clinical policy update are:

• Which patients with mild TBI should have a noncontrast head CT scan in the ED?
• Is there a role for head magnetic resonance imaging (MRI) over noncontrast CT in the ED evaluation of a patient with acute mild TBI?
• In patients with mild TBI, are brain-specific serum biomarkers predictive of an acute traumatic intracranial injury?
• Can a patient with an isolated mild TBI and a normal neurologic evaluation result be safely discharged from the ED if a noncontrast head CT scan shows no evidence of intracranial injury?

The 2002 document included a question regarding the role of plain film radiography in assessing mild TBI patients. This question was not included in this update, because there has been no new evidence regarding this subject.

Thus the original recommendation remains unchanged:

“Level B recommendation: Skull film radiographs are not recommended in the evaluation of mild TBI. Although the presence of a skull fracture increases the likelihood of an intracranial lesion, its sensitivity is not sufficient to be a useful screening test. Indeed, negative findings on skull films may mislead the clinician.”

Outcome measures were adjusted to the question being addressed. Presence of an acute intracranial injury on noncontrast head CT scan was chosen as the primary outcome measure for the questions regarding CT scanning, the use of MRI, and the utility of biomarkers. Neurologic deterioration was the primary outcome measure for the final question regarding discharge.