Which clinical signs and symptoms are useful in accurately diagnosing a severe intracranial injury after minor head trauma in adults?
Specific individual risk factors, clinical signs, and symptoms are useful in identifying adults with minor head trauma who are at risk of severe intracranial injury. The absence of all features of the Canadian CT Head Rule and New Orleans Criteria is also highly accurate for identifying adults at low risk of severe injury. (Level of Evidence = 1b)
Adults who appear well and have a Glasgow Coma Scale (GCS) score of 13 or higher after traumatic brain injury are defined as having minor head trauma. These investigators searched Medline and the Cochrane Library, as well as pertinent references from retrieved articles, for English-language studies of adults (18 years or older) with head trauma who presented for evaluation with GCS scores ranging from 13 to 15. Inclusion criteria included diagnostic accuracy studies focusing on severe intracranial injuries requiring prompt intervention. A total of 14 studies (N = 23,079) met inclusion criteria with a severe intracranial injury prevalence of 7.1% (95% confidence interval [CI], 6.8% to 7.4%) and a prevalence of injuries leading to death or requiring neurosurgical intervention of 0.9% (95% CI, 0.78% to 1.0%).
The highest risk factors included pedestrians struck by motor vehicles (likelihood ratio range, 3.0 to 4.3), age at least 65 years (positive likelihood ratio [LR+] = 2.3; 95% CI, 1.8 to 3.1), and age at least 60 years (LR+ = 2.2; 95% CI, 1.6 to 3.2). Useful symptoms included the presence of vomiting, especially at least two episodes (LR+ = 3.6; 95% CI, 3.1 to 4.1), or posttraumatic seizures (LR+ = 2.5; 95% CI, 1.3 to 4.3). Likelihood ratios for loss of consciousness or the presence of headache were minimally, if at all, useful for predicting adverse outcomes. Useful physical signs included features suspicious for skull fractures: visible open skull fracture, palpable depressed skull fracture, postauricular ecchymosis (Battle sign), hemotympanum, cerebrospinal fluid otorrhea, or raccoon eyes (LR+ = 16; 95% CI, 3.1 to 59). A GCS score of 13 (LR+ = 4.9; 95% CI, 2.8 to 8.5), a GCS score of less than 15 at two hours after injury (LR range, 1.6 to 7.6), any decline in GCS score (LR range, 3.4 to 16), or a focal neurologic deficit (LR range, 1.9 to 7.0) also increased the likelihood of severe intracranial injury.
Two clinical decision rules, including the Canadian CT Head Rule and the New Orleans Criteria, were also evaluated. The absence of all features on the Canadian CT Head Rule lowers the probability of a severe injury to 0.31% (95% CI, 0% to 4.7%), with the corresponding absence of any of the New Orleans Criteria lowering the risk to 0.61% (95% CI, 0.08% to 6.0%).
Study design: Systematic review
Funding source: Foundation
Setting: Various (meta-analysis)
Reference: EasterJSHaukoosJSMeehanWPNovackVEdlowJAWill neuroimaging reveal a severe intracranial injury in this adult with minor head trauma? The rational clinical examination systematic review. JAMA2015;314(24):2672–2681.