The leading cause of traumatic brain injury (TBI) is gunshot wounds to the head in many areas in the U.S. This can be because of gang violence, homicides, suicides, or accidents.
Gunshot wounds to the head due to suicide have a low chance of survival. There is a greater chance of death if the gunshot wound to the head is suicide. According to the CDC, in 2010, people under the age of 25 used firearms in 44% of suicide deaths. Firearms are the main method of suicide by males (56%) in 2012.
A wound where the gun shot reaches the cranium but does not exit, it is a penetrating wound. If the gunshot passes through the head, with exit and entrance wounds, it is a perforating wound.
Many different factors can contribute to the damage done from a gunshot wound to the head. A gunshot near the forehead to the right frontal lobe tip and high above the base of the skull usually has mild damage as no major structures were based through. A bullet from the left frontal lobe tip to the temporal lobe or brain stem can injure extremely important areas of the brain.
UNITED STATES STATISTICS
- 12% of all TBIs (traumatic brain injuries)are caused by firearms, firearms in ages 25-34 are the main cause of TBI
- 35% of all TBI deaths are because of gunshot wounds to the head
- Around 90% of the time gunshot wounds are fatal and patient will die before reaching hospital
- 50% of surviving victims will suffer from seizures and need anti-epilepsy medicine
SURGICAL TREATMENT
Gunshot wounds to the head patients are resusicaited when arriving at the hospital. If oxygenation and blood pressure remain stable, an urgent CT scan of the brain will be taken. Surgery treatment is determined based on:
- The level of consciousness: Glasgow Coma Scale 1-15 (GCS); below 7 or 8 is a coma
- Degree of brainstem neurological function
- CT scan
If a patient is in a deep coma with minimal brainstem function and no signs of an intracranial hematoma that is causing the coma, death is a likely outcome. If the CT scan shows a hematime, a craniotomy can be performed for clot removal, debris removal, and devitalized tissue removal. A craniectomy is often performed because of pressure build up in the skull. A craniectomy is a surgery where a large portion of the skill is removed to decrease a pressure build up in the skull.
To determine treatment, it is important to know the bullet path. The brain has two hemispheres with four lobes each. Each lobe has many different functions. Deeper parts of the brain can control body and brain function and make connections. The cerebellum in the lower back brain works with motor coordination. The brainstem connects to the upper portions of the brain, that relate to thinking, to the spinal cord.
Bullet paths that cross deep structures in the brain or the brainstem have a poorer outcome. Damage to the right hemisphere can leave the gunshot victim with motor and sensory function loss on the left side. Both sides of the brain control cognition, memory, speech, and vision. Damage to only one hemisphere might leave a person with function loss but not complete function loss.
The best case scenario for a gunshot wound to the head victim would be a superficial injury that reaches only one hemisphere and one lobe. 1-2 weeks after the incident is referred to as the critical care stage. After this period, the recovery depends on the amount of damage done, the swelling levels, the pressure build up in the head, etc. Neurological recovery may take months or years. Survivors will likely need rehabilitation.
OUTCOME
Blood loss is the main reason for immediate death following a gunshot. There is no time to stop the bleeding if the damage is done to certain blood vessels. The victim may bleed to death or form a severe blood clot that compresses brain tissue. If the victim does survive the initial blood loss, the pressure in the skull continually increases and is a problem. There is injury from both the direct penetration of the brain and from transmission of a pressure wave from the high velocity projectile going through the brain tissue when the bullet goes through the brain. Brain swelling can lead to death.
Contributing Factors
- Bullet entry or exit site
- Part of brain that was damaged
- Bullet fragmentation
- Caliber of bullet and type of weapon
- Distance between gun and victim
- Victims age and health
- GCS score initially
- Reactivity and dilation of pupils
- Brainstem reflex
- Blood pressure
- Oxygenation right after the injury
CONCLUSIONS
Admission Glascow Coma score (GCS), bullet path, pupillary response to light and patenty of basal brain cerebrospinal spaces are major factors that determine the outcome of victims with a gunshot wound to the head.
