Diffuse Axonal Injury
Diffuse axonal injury occurs in about half of all severe head traumas, making it one of the most common traumatic brain injuries. It can also occur in moderate and mild brain injury. A diffuse axonal injury falls under the category of a diffuse brain injury. This means that instead of occurring in a specific area, like a focal brain injury, it occurs over a more widespread area.
In addition to being one of the most common types of brain injuries, it’s also one of the most devastating. As a matter of fact, severe diffuse axonal injury is one of the leading causes of death in people with traumatic brain injury.
What Are The Causes of Diffuse Axonal Injury
Diffuse axonal injury isn’t the result of a blow to the head. Instead, it results from the brain moving back and forth in the skull as a result of acceleration or deceleration.
- Automobile accidents
- Sports-related accidents
- Violence
- Falls
- Child abuse such as Shaken Baby Syndrome
When acceleration or deceleration causes the brain to move within the skull, axons, the parts of the nerve cells that allow neurons to send messages between them, are disrupted. As tissue slides over tissue, a shearing injury occurs. This causes the lesions that are responsible for unconsciousness, as well as the vegetative state that occurs after a severe head injury.
A diffuse axonal injury also causes brain cells to die, which cause swelling in the brain. This increased pressure in the brain can cause decreased blood flow to the brain, as well as additional injury. The shearing can also release chemicals which can contribute to additional brain injury.
Symptoms of Diffuse Axonal Injury
The main symptom of diffuse axonal injury is lack of consciousness, which can last up to six hours or more. A person with a mild or moderate diffuse axonal injury who is conscious may also show other signs of brain damage, depending upon which area of the brain is most affected.
