The skull base comprises the floors of the anterior, middle, and posterior cranial fossae. Trauma resulting in fractures to the basilar area typically does not have localizing symptoms. Indirect signs of the injury may include visible evidence of bleeding from the fracture into surrounding soft tissue, such as a Battle sign or "raccoon eyes." Bleeding into other structures such as hemotympanum and blood in the sphenoid sinus, evident as an air-fluid level on CT, may also be seen. Cerebrospinal fluid (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.
Emergency Department Treatment and Disposition
The mainstay of management is to identify underlying brain injury, which is best accomplished by computed tomography (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, mandates 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.
Battle Sign. Ecchymosis in the postauricular area develops when the fracture line communicates with the mastoid air cells, resulting in accumulation of blood in the cutaneous tissue. This patient sustained injuries several days prior to presentation. (Photo contributor: Frank Birinyi, MD.)
Battle Sign. A subtle Battle sign is seen in this patient with head trauma. This sign may take hours to develop fully. (Photo contributor: Lawrence B. Stack, MD.)
Raccoon Eyes. Ecchymosis in the periorbital area, resulting from bleeding from a fracture site in the anterior portion of the skull base. This finding may also be caused by facial fractures. (Photo contributor: Frank Birinyi, MD.)
Early Racoon Eyes. Subtle periorbital ecchymosis manifests 1 hour after a blast injury. (Photo contributor: Kevin J. Knoop, MD, MS.)
Hemotympanum. Seen in a basilar skull fracture when the fracture line communicates with the auditory canal, resulting in bleeding into the middle ear. Blood can be seen behind the tympanic membrane. (Photo contributor: Richard A. Chole, MD, PhD.)