Diffuse Axonal Injury from a Car Accident

A diffuse axonal injury is an extensive type of brain injury that affects a large portion of the brain and accounts for more than half of the cases involving severe head traumas.

Because brain injuries are widespread and extensive, the patient usually slips into a coma that could last for months. Unfortunately, 90% of the patients who sustain a diffuse axonal injury will end up in a coma and never regain consciousness. If ever they do regain their consciousness and wake up, more often than not, they suffer from debilitating and lifelong impairments that will require intensive therapy.

Sadly, there is no known cure for diffuse axonal injury. Some medications and drugs could somewhat improve the outcome after the accident, and palliative care and therapy to prevent worsening symptoms, manage disabilities and improve quality of life.

The most common causes of diffuse axonal injury are vehicular accidents, sports-related injuries, severe falls, and violence.

A diffuse axonal injury results from the abrupt acceleration and deceleration of the brain within the skull. The parts of the brain that hit the skull sustain injuries, and the soft brain tissues glide over each other, resulting in the abnormal stretching of neurons and brain structures.

Other physiological processes also occur during the injury. There is a loss of consciousness and the start of the inflammatory process. Neuroinflammation worsens diffuse axonal injury and intensifies its devastating effects. As the brain swells and fluids accumulate inside the skull, the intracranial pressure also increases. Compression of the brain and reduction of its blood flow contribute to the devastating effects of the diffuse axonal injury.

Shearing of the brain typically happens in diffuse axonal injury and commonly affects the neuronal axons that pass through the junction where the white and gray matters of the brain meet.

As the brain shifts violently inside the skull, the axons that connect the neurons to each other are stretched to abnormal lengths, causing axonal injury and tearing. It then results in loss of consciousness, comatose, and impairment of the motor, sensory, and cognitive functions.

The damaged axons will also trigger the inflammatory process. They release destructive enzymes and chemicals that will affect the nearby neurons, further worsening the diffuse axonal injury.

There are two categories of Traumatic brain injury – focal brain injury and diffuse brain injury. Both of them are caused by trauma to the head, resulting in brain injury.

A focal brain injury occurs in a specific and confined area of the brain. Examples of focal brain injury are gunshot wounds to the head, stroke, vehicular accidents, and blows to the head.

On the other hand, a diffuse brain injury occurs in a widespread area of the brain, so the injuries are more extensive and more damaging since it covers a large portion of the brain. Examples of a diffuse brain injury are diffuse axonal injury from a car accident, brain hypoxia resulting from diminished blood supply to the brain, and brain swelling that increases intracranial pressure.