Basilar skull fracture

A basilar skull fracture (or Basal skull fracture) is a linear skull fracture involving the base of the skull. This type of fracture is rare, occurring as the only fracture in just 4% of severe head injury patients. Moreover, it is most often associated with leakage in the cerebrospinal fluid of the brain into the ear (CSF otorrhea) or the nose (CSF rhinorrhea). These signs are pathognomonic for basilar skull fracture. .

Basilar skull fractures can be caused by a blow to the back of the head, or by sudden deceleration of torso but not head (as in traffic accidents), resulting in separation of the suture between the occipital and temporal bones.

Anatomy
Basilar skull fractures commonly involve the roof of the orbits, the sphenoid bone, or portions of the temporal bone.

Bones may be broken around the foramen magnum, the hole in the base of the skull through which the spinal cord enters and becomes the brain stem, creating the risk that blood vessels and nerves exiting the hole may be damaged.

Due to the proximity of the cranial nerves, injury to those nerves may occur. This can cause palsy of the facial nerve or oculomotor nerve or hearing loss due to damage of cranial nerve VIII.

Clinical manifestations

 * Battle's sign - is ecchymosis of the mastoid process of the temporal bone.
 * Raccoon eyes - is periorbital ecchymosis i.e. "black eyes"
 * Cerebrospinal fluid rhinorrhea
 * Cranial nerve palsy
 * Bleeding from the nose and ears
 * In 1 to 10% of patients, ocular nerve entrapment occurs: the ocular nerve is pressed by the broken skull bones, causing irregularities in vision.

Prognosis
Non-displaced fractures usually heal without intervention. Patients with basilar skull fractures are especially likely to get meningitis.

Notable cases
Basilar skull fracture is a common cause of death in auto racing accidents, notably that of Dale Earnhardt in the 2001 Daytona 500, Roland Ratzenberger in the 1994 San Marino Formula One Grand Prix, Gonzalo Rodriguez in practice for the 1999 Laguna Seca Grand Prix, Tony Bettenhausen in practice for the 1961 Indy 500, and Greg Moore at the 1999 Marlboro 500 at California Motor Speedway.