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Clinical Summary

The skull “base” comprises the frontal bone, occiput, occipital condyles, clivus, carotid canals, petrous portion of the temporal bones, and the posterior sphenoid wall. A basilar skull fracture is basically a linear fracture of the skull base. Trauma resulting in fractures to this area typically does not have localizing symptoms. Indirect signs of the injury may include visible evidence of bleeding from the fracture into the surrounding soft tissues of the base of the head, such as a Battle sign or “raccoon eyes.” Bleeding into other structures, blood in the middle ear causing hemotympanum, or blood in the sphenoid sinus seen as an air-fluid level on CT may also be seen. CSF leaks may also be evident and noted as clear or pink rhinorrhea. If CSF is present, a dextrose stick test may be positive. The fluid can be placed on filter paper, and a “halo” or double ring may be seen. Bedsheets may reveal the halo sign.


Battle Sign. Ecchymosis in the postauricular area develops when the fracture line communicates with the mastoid air cells, resulting in blood accumulating in the cutaneous tissue. This patient had sustained injuries several days prior to presentation. (Photo contributor: Frank Birinyi, MD.)

Management and Disposition

Identify underlying brain injury, which is best accomplished by head CT. CT is also the best diagnostic tool for identifying the fracture site, but fractures may not always be evident. Evidence of open communication, such as a CSF leak, requires neurosurgical consultation and admission. Otherwise, the decision for admission is based on the patient’s clinical condition, other associated injuries, and evidence of underlying brain injury as seen on CT. The use of antibiotics in the presence of a CSF leak is controversial because of the possibility of selecting resistant organisms.


  1. Clinical manifestations of basilar skull fracture may take several hours to fully develop.

  2. Have a low threshold for head CT in any patient with head trauma, loss of consciousness, change in mental status, severe headache, visual changes, or nausea or vomiting.

  3. The use of filter paper or a dextrose stick test to determine if CSF is present in rhinorrhea is not 100% reliable.


Battle Sign. A striking Battle sign is seen in this patient with head trauma. This finding may take hours to days to develop. (Photo contributor: David Effron, MD.)


Raccoon Eyes. Acute periorbital ecchymosis seen in this patient with a basilar skull fracture. These findings may also be caused by facial fractures. (Photo contributor: Shannon Koh, MD.)


Early Raccoon Eyes. Subtle periorbital ecchymosis manifests 1 hour after a blast injury. ...

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