Penetrating head injury

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Penetrating head injury
Other namesOpen-head injury
An illustration of a brain after an "encircling" gunshot wound showing the pattern of injury caused by the bullet's path
SpecialtyEmergency medicine Edit this on Wikidata

A penetrating head injury, or open head injury, is a

projectiles or objects of lower velocity such as knives, or bone fragments from a skull fracture that are driven into the brain. Head injuries caused by penetrating trauma are serious medical emergencies and may cause permanent disability or death.[2]

A penetrating head injury involves "a wound in which an object breaches the cranium but does not exit it." In contrast, a perforating head injury is a wound in which the object passes through the head and leaves an

exit wound.[2]

Cause

3-D CT scan showing a penetrating head injury by a screwdriver[3]
An 1868 illustration showing the perforating head injury of Phineas Gage, a railroad worker who had a tamping iron driven through his skull in an 1848 accident.

In penetrating injury from high-velocity missiles, injuries may occur not only from initial

exit wounds, or packed up against the sides of the cavity formed by the missile.[2]

Low-velocity objects usually cause penetrating injuries in the regions of the

orbital surfaces, where the bones are thinner and thus more likely to break.[2] Damage from lower-velocity penetrating injuries is restricted to the tract of the stab wound, because the lower-velocity object does not create as much cavitation.[2] However, low-velocity penetrating objects may ricochet inside the skull, continuing to cause damage until they stop moving.[4]

Pathophysiology

Though it is more likely to cause

focal (that is, it affects a specific area of tissue).[2]

Studies with

blood clotting.[6]

While blunt trauma to the head does not present a risk of shock due to hemorrhage, penetrating head trauma does.[5]

Diagnosis and treatment

A person with a penetrating head injury may be evaluated using X-ray, CT scan, or MRI (MRI can only be used when the penetrating object would not be magnetic, because MRI uses magnetism and could move the object, causing further injury).[5]

Surgery may be required to debride or repair the injury or to relieve excessive intracranial pressure.[5] Intracranial pressure is monitored and attempts are made to maintain it within normal ranges.[5] Intravenous fluids are given and efforts are taken to maintain high blood oxygen levels.[5]

Prognosis

The highest-velocity injuries tend to have the worst associated damage.[7] A study published in 1991, which documented 314 individuals who had had penetrating cranial injuries caused by gunshot wounds, found that 73% died from their injuries at the scene of the incident, and a further 19% ultimately died later, thus indicating a total mortality rate of 92%.[2] Perforating injuries have an even worse prognosis.[2]

Penetrating head trauma can cause impairment or loss of abilities controlled by parts of the brain that are

damaged. A famous example is Phineas Gage, whose personality appears to have changed (though not as dramatically as usually described) after a perforating injury to his frontal lobe
(s).

People with

respiratory distress, hypotension, or cerebral vasospasm are more likely to have worse outcomes.[5]

People with penetrating head trauma may have complications such as

neurogenic pulmonary edema.[5][8] Up to 50% of patients with penetrating brain injuries get late-onset post-traumatic epilepsy.[9]

See also

References

  1. ^ University of Vermont College of Medicine. "Neuropathology: Trauma to the CNS." Accessed through web archive on August 8, 2007.
  2. ^ a b c d e f g h i j Vinas FC and Pilitsis J. 2006. "Penetrating Head Trauma." Emedicine.com. Retrieved on February 6, 2007.
  3. PMID 17169147
    .
  4. ^ Brain Injury Association of America (BIAUSA). "Types of Brain Injury." Archived 2007-10-18 at the Wayback Machine Retrieved on February 6, 2007.
  5. ^
    PMID 16962454
    .
  6. ^ Orlando Regional Healthcare, Education and Development. 2004. "Overview of Adult Traumatic Brain Injuries." Archived 2008-02-27 at the Wayback Machine Retrieved on January 16, 2008.
  7. ^ Dawodu S. 2007. "Traumatic Brain Injury: Definition, Epidemiology, Pathophysiology" Emedicine.com. Retrieved on February 6, 2007.
  8. S2CID 18066655
    .
  9. ^ Shepherd S. 2004. "Head Trauma." Emedicine.com. Retrieved on February 6, 2007.

External links

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