Basilar skull fracture | |
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Other names | Basal skull fracture, skull base fractures [1] |
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A subtle temporal bone fracture as seen on a CT scan | |
Specialty | Emergency medicine, neurosurgery |
Symptoms | Bruising behind the ears, bruising around the eyes, blood behind the ear drum [1] |
Complications | Cerebrospinal fluid leak, facial fracture, meningitis [2] [1] |
Types | Anterior, central, posterior [1] |
Causes | Trauma [1] |
Diagnostic method | CT scan [1] |
Treatment | Based on injuries inside the skull [1] |
Frequency | ≈12% of severe head injuries [1] |
A basilar skull fracture is a break of a bone in the base of the skull. [1] Symptoms may include bruising behind the ears, bruising around the eyes, or blood behind the ear drum. [1] A cerebrospinal fluid (CSF) leak occurs in about 20% of cases and may result in fluid leaking from the nose or ear. [1] Meningitis occurs in about 14% of cases. [2] Other complications include injuries to the cranial nerves or blood vessels. [1]
A basilar skull fracture typically requires a significant degree of trauma to occur. [1] It is defined as a fracture of one or more of the temporal, occipital, sphenoid, frontal or ethmoid bone. [1] Basilar skull fractures are divided into anterior fossa, middle fossa and posterior fossa fractures. [1] Facial fractures often also occur. [1] Diagnosis is typically by CT scan. [1]
Treatment is generally based on the extent and location of the injury to structures inside the head. [1] Surgery may be performed to seal a CSF leak that does not stop, to relieve pressure on a cranial nerve or repair injury to a blood vessel. [1] Prophylactic antibiotics do not provide a clinical benefit in preventing meningitis. [2] [3] A basilar skull fracture occurs in about 12% of people with a severe head injury. [1]
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. [5]
While not absolute, three principal types of basilar skull fractures are recognized, based on the direction and location of the impacting force:
In children, fractures may not occur due to suture separation and greater bone flexibility.
Evidence does not support the use of preventive antibiotics, regardless of the presence of a cerebrospinal fluid leak. [3] [2]
Non-displaced fractures usually heal without intervention. Patients with basilar skull fractures are especially likely to get meningitis. [8] The efficacy of prophylactic antibiotics in these cases is uncertain. [9]
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. [10]
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 driver Roland Ratzenberger; 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. Ernie Irvan is a survivor of a basilar skull fracture sustained at an accident during practice at the Michigan International Speedway in 1994. [11] Race car drivers Stanley Smith and Rick Carelli also survived a basilar skull fracture. [12] [13]
To prevent basilar skull fractures, many motorsports sanctioning bodies mandate the use of head and neck restraints, such as the HANS device. [14] [15] [16] [17] The HANS device has demonstrated its life-saving abilities multiple times, including Jeff Gordon at the 2006 Pocono 500, Michael McDowell at qualifying for the 2008 Samsung 500, [18] Robert Kubica at the 2007 Canadian Grand Prix, and Elliott Sadler at the 2003 EA Sports 500 and the 2010 Sunoco Red Cross Pennsylvania 500. [19]