Diffuse Axonal Injury (DAI)

Lt Col Reynolds
One of the most common and severe types of brain injury is known as diffuse axonal injury, or DAI. With DAI, the damage to the brain occurs over a large area, and is one of the major causes of unconsciousness and long-term coma after traumatic brain injury. Dr. Green, what else can you tell us about DAI?

Dr. Green
Well, Dr. Reynolds, DAI refers to the widespread damage to the brain’s white matter. White matter is composed of bundles of axons, which, like the wires in a computer, connect different areas of the brain to one another. DAI is the result of shearing forces, which stretch, twist, or tear these axon bundles. This type of injury usually results from rotational forces or violent stopping, such as in auto collisions, falls, and assaults.

Vehicle collisions are the most frequent causes of DAI. Another common cause is child abuse, for example, shaken baby syndrome. Although diffuse axonal injury seldom kills, the outcome is often not predictable. In severe DAI, patients are frequently in a coma, and many will never regain consciousness.