Diffuse Axonal Injury: Causes, Symptoms, Diagnosis, and Treatment

diffuse axonal injury mri

Diffuse Axonal Injury (DAI), also known as Traumatic Axonal Injury (TAI), is a term used to describe a severe form of brain trauma.

DAI refers to a traumatic brain injury that occurs due to acceleration/deceleration or a rotational force that makes the brain rapidly shift inside the skull.

This injury results in the disconnection of the axons, the nerve fibers that carry electrical impulses to neurons, muscles, and glands.

That causes damage to several sections of the brain and usually leaves patients in a coma.

That is why some medical experts define DAI as a coma lasting a minimum of 6 hours after a traumatic brain injury.

DAI is very difficult to detect even when doctors use a Computed Tomography (CT) scan.


More often than not, DAI occurs as the result of high-speed motor vehicle accidents.

In these particular cases, the cause of DAI is a combination of acceleration, deceleration, and contact forces.

When this combination becomes strong enough, it can produce a shearing force that affects neuro-fibers by twisting, stretching, or severing axons.

That ends up disrupting the flow of electrical impulses that travel through the nerves, which results in the eventual death of nerve cells producing swelling in the brain.

When the brain swells the pressure on the skull increases, which leads to complications such as restricted blood supply to brain tissues and even brain herniation.

Other circumstances or events that may cause DAI are sport-related injuries and falls that make the head whip rapidly back and forward.

In some cases, when the patients suffer constant physical trauma as in taking several blows to the head, the force can cause the brain to rapidly and violently move inside the skull.

Such movement can severely damage the nerve fibers connection and produce DAI.

Some patients may develop this type of brain damage due to Shaken Baby Syndrome, a form of child abuse that consists of forcefully shaking a toddler.

Given a baby’s blood vessels, muscles, and organs are softer and weaker, the force produced by this action can cause the brain of the infant to move and hit the inside of the skull repeatedly.

The resulting trauma can lead to several forms of brain injury, including DAI.

Other potential causes of DAI are related to construction working and the shockwaves produced by explosions.


The most typical sign of DAI is a long-lasting loss of consciousness. A patient that has DAI can stay in a profound coma for 6 hours or even more extended periods.

However, if the damage isn’t severe patients may display other symptoms of typical brain trauma.

In these cases, people may regain consciousness after suffering a mild DAI but showcase signs such as nausea, loss of balance, dizziness, disorientation or confusion, and changes in perception or cognition.

Along with the altered cognition, DAI can cause some remarkable behavioral changes as well as unexplained mood swings.

Other noticeable signs are difficulty in recognizing or recalling words, places, people, or animals that should otherwise be familiar to the patient.

This difficulty can result in trouble performing simple tasks such as reading or even speaking.


Given the wide variety of symptoms that come and go depending on the severity of the damage, medical experts have a hard time diagnosing DAI.

More often than not, doctors consider a Magnetic Resonance Imaging (MRI) scan the best option for assessing suspected DAI.

Cases of this particular form of brain trauma feature several small regions of susceptibility artifact in the corpus callosum. When the patients suffered more severe damage, these areas appear in the brainstem.


The first thing doctors may need to do is reducing any swelling inside of the brain before it causes further damage. The sooner the medical experts act, the better for the patient.

Once doctors managed to stabilize the patient, they’ll likely need to create a comprehensive treatment plan.

There’s no surgery available to deal with DAI, which is why most treatments focus on rehabilitation. This recovery program consists of the following therapeutic measures:

  • Speech therapy
  • Physical therapy
  • Occupational therapy
  • Recreational therapy
  • Counseling

The possibility of people recovering from DAI depends on the extent and severity of the damage. In the most severe cases, a patient may remain in a vegetative state or even die because of this brain injury.