Basilar skull fracture

Basilar skull fracture
Classification and external resources

A subtle temporal bone fracture as seen on CT in a person with a severe head injury
ICD-10 S02.1
ICD-9 801.1
eMedicine med/2894

A basilar skull fracture (or basal skull fracture) is a fracture of the base of the skull, typically involving the temporal bone, occipital bone, sphenoid bone, and/or ethmoid bone.

This type of fracture is rare, occurring as the only fracture in just 4% of severe head injury patients.[1][2]

Such fractures can cause tears in the membranes surrounding the brain, or meninges, with resultant leakage of the cerebrospinal fluid (CSF). The leaking fluid may accumulate in the middle ear space, and dribble out through a perforated eardrum (CSF otorrhea) or into the nasopharynx via the eustachian tube, causing a salty taste. CSF may also drip from the nose (CSF rhinorrhea) in fractures of the anterior skull base, yielding a halo sign. These signs are pathognomonic for basilar skull fracture.[3]

Contents

Signs and symptoms

Pathophysiology

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.[4]

Bones may be broken around the foramen magnum, the hole in the base of the skull through which the spinal cord exits and becomes the brain stem, creating the risk that blood vessels and nerves exiting the hole may be damaged.[5]

Due to the proximity of the cranial nerves, injury to those nerves may occur.[3] This can cause palsy of the facial nerve or oculomotor nerve or hearing loss due to damage of cranial nerve VIII.[3]

Management

Evidence does not support the use of prophylactic antibiotics regardless of the presence of a cerebral spinal fluid leak.[6]

Prognosis

Non-displaced fractures usually heal without intervention. Patients with basilar skull fractures are especially likely to get meningitis.[7] Unfortunately, the role of prophylactic antibiotics in these cases is unclear.[8]

Temporal bone fractures

Acute injury to the internal carotid artery (carotid dissection, occlusion, pseudoaneurysm formation) may be asymptomatic or result in life-threatening hemorrhage. 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.[9]

Society and culture

Basilar skull fracture is a common cause of death in auto racing accidents:

(It had been posted here that Dan Wheldon died of a basilar skull fracture but that is inaccurate. Dan Wheldon passed from injuries due to blunt-force head trauma when the top of his car struck a post that was part of the retaining fence at Las Vegas Motor Speedway.)

To prevent this injury, all major motor sports sanctioning bodies now mandate the use of head and neck restraints, such as the HANS device.

References

  1. ^ Graham DI and Gennareli TA. Chapter 5, "Pathology of Brain Damage After Head Injury" Cooper P and Golfinos G. 2000. Head Injury, 4th Ed. Morgan Hill, New York.
  2. ^ Orlando Regional Healthcare, Education and Development. 2004. "Overview of Adult Traumatic Brain Injuries." Retrieved on January 16, 2008.
  3. ^ a b c d Singh J and Stock A. 2006. "Head Trauma." Emedicine.com. Retrieved on January 26, 2007.
  4. ^ http://emedicine.medscape.com/article/248108-overview
  5. ^ Brain Injury Association of America (BIAUSA). "Types of Brain Injury." Retrieved on January 26, 2007.
  6. ^ Ratilal, BO; Costa, J, Sampaio, C, Pappamikail, L (2011 Aug 10). "Antibiotic prophylaxis for preventing meningitis in patients with basilar skull fractures.". Cochrane database of systematic reviews (Online) (8): CD004884. PMID 21833952. 
  7. ^ Dagi TF, Meyer FB, and Poletti CA. 1983. The incidence and prevention of meningitis after basilar skull fracture. American Journal of Emergency Medicine. Volume 1, Issue 3, Pages 295-298. PMID 6680635. Retrieved on March 16, 2007.
  8. ^ http://www.bestbets.org/bets/bet.php?id=96
  9. ^ Resnick DK, Subach BR, Marion DW. The Significance of Carotid Canal Involvement in Basilar Cranial Fracture. Neurosurgery. 1997 40(6):1177-1181.ISSN: 0148-396X UI: 9179890

External links