Gunshot wounds to the head have become a leading cause of head injury in many United States cities. They are also the most lethal of all firearm injuries. It is estimated that gunshot wounds to the head have a greater than 90% fatality rate for United States civilians, and at least two-thirds of the victims die before ever reaching a hospital. Because of the high mortality rate associated with gunshot wounds to the head, they account for only approximately 10% of all traumatic brain injury patients who survive.
Virtually all cranial gunshot victims are aggressively resuscitated upon initial arrival at the hospital. If a patient’s blood pressure and oxygenation can be maintained, an urgent CT scan of the brain is obtained. The decision to proceed with surgical management of the gunshot wound is based on three factors:
- The level of consciousness (GCS)
- The degree of brainstem neurological function
- The findings on the CT scan.
In virtually all patients who are deeply comatose with minimal evidence of brainstem function and no evidence of an intracranial hematoma that might be causing the coma, a fatal outcome is almost certain. In such patients, aggressive treatment is rarely pursued because of the futility of the situation. If, however, there is a hematoma seen on the CT scan, emergent craniotomy and clot evacuation may be warranted, as some of these individuals will make a significant recovery. For other patients who exhibit purposeful motor activity, urgent and aggressive neurosurgical care is provided, when indicated.
The predictors of poor neurological outcome or death after a gunshot wound to the head include
- Low initial Glasgow Coma Scale score
- Older age
- Presence of low blood pressure
- Inadequate oxygenation early after injury
- Dilated non-reactive pupils
- Not surprisingly, the bullet trajectory through the brain has major significance. Bullets that traverse the brainstem, multiple lobes of the brain, or the ventricular system (chambers where cerebrospinal fluid is located) are particularly lethal. Many initial survivors develop uncontrollable intracranial pressure and subsequently succumb.