Basilar skull fracture
|Basilar skull fracture|
|Synonyms||Basal skull fracture, skull base fractures|
|A subtle temporal bone fracture as seen on CT in a person with a severe head injury|
|Specialty||Emergency medicine, neurosurgery|
|Symptoms||Bruising behind the ears, bruising around the eyes, blood behind the ear drum|
|Complications||Cerebrospinal fluid leak, facial fracture, meningitis|
|Types||Anterior, central, posterior|
|Diagnostic method||CT scan|
|Treatment||Based on injuries inside the skull|
|Frequency||~12% of severe head injuries|
A basilar skull fracture is a break of a bone in the base of the skull. Symptoms may include bruising behind the ears, bruising around the eyes, or blood behind the ear drum. A cerebrospinal fluid (CSF) leak occurs in about 20% of cases and can result in fluid leaking from the nose or ear. Meningitis is a complication in about 14% of cases. Other complications include cranial nerve or blood vessel injury.
They typically require a significant degree of trauma to occur. The break is of at least one of the following bones: temporal bone, occipital bone, sphenoid bone, frontal bone, or ethmoid bone. They are divided into anterior fossa, middle fossa, and posterior fossa fractures. Facial fractures often also occur. Diagnosis is typically by CT scan.
Treatment is generally based on the injury to structures inside the head. Surgery may be done for a CSF leak that does not stop or an injury to a blood vessel or nerve. Preventative antibiotics are of unclear use. It occurs in about 12% of people with a severe head injury.
Signs and symptoms
- Battle's sign – bruising of the mastoid process of the temporal bone.
- Raccoon eyes – bruising around the eyes, i.e. "black eyes"
- Cerebrospinal fluid rhinorrhea
- Cranial nerve palsy
- Bleeding (sometimes profuse) from the nose and ears
- Conductive or perceptive deafness, nystagmus, vomitus
- In 1–10% of patients, optic nerve entrapment occurs. The optic nerve is compressed by the broken skull bones, causing irregularities in vision.
- Serious cases usually result in death
Basilar skull fractures include breaks in the posterior skull base or anterior skull base. The former involve the occipital bone, temporal bone, and portions of the sphenoid bone; the latter, superior portions of the sphenoid and ethmoid bones. The temporal bone fracture is encountered in 75% of all basilar skull fractures and may be longitudinal, transverse or mixed, depending on the course of the fracture line in relation to the longitudinal axis of the pyramid.
Bones may be broken around the foramen magnum, the hole in the base of the skull through which the brain stem exits and becomes the spinal cord, 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 loss of function of the facial nerve or oculomotor nerve or hearing loss due to damage of cranial nerve VIII.
Non-displaced fractures usually heal without intervention. Patients with basilar skull fractures are especially likely to get meningitis. Unfortunately, the efficacy of prophylactic antibiotics in these cases is uncertain.
Temporal bone fractures
Acute injury to the internal carotid artery (carotid dissection, occlusion, pseudoaneurysm formation) may be asymptomatic or result in life-threatening bleeding. They are almost exclusively observed when the carotid canal is fractured, although only a minority of carotid canal fractures result in vascular injury. Involvement of the petrous segment of the carotid canal is associated with a relatively high incidence of carotid injury.
Society and culture
Basilar skull fractures are a common cause of death in many motor racing accidents. Drivers who have died as a result of basilar skull fractures include Formula One drivers Roland Ratzenberger and Ayrton Senna; IndyCar drivers Bill Vukovich Sr., Tony Bettenhausen Sr., Floyd Roberts, and Scott Brayton; NASCAR drivers Dale Earnhardt Sr., Adam Petty, Tony Roper, Kenny Irwin Jr., Neil Bonnett, John Nemechek, J.D. McDuffie, and Richie Evans; CART drivers Jovy Marcelo, Greg Moore, and Gonzalo Rodriguez; and ARCA drivers Blaise Alexander and Slick Johnson.
To prevent this injury many motor sports sanctioning bodies mandate the use of head and neck restraints, such as the HANS device. The HANS device has demonstrated its life-saving abilities multiple times, including Jeff Gordon at the 2006 Pocono 500, Michael McDowell at the Texas Motor Speedway in 2008, Robert Kubica at the 2007 Canadian Grand Prix, and Elliott Sadler at the Pocono Red Cross 500 in 2010.
- Baugnon, KL; Hudgins, PA (August 2014). "Skull base fractures and their complications". Neuroimaging Clinics of North America. 24 (3): 439–65, vii–viii. doi:10.1016/j.nic.2014.03.001. PMID 25086806.
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