Understanding Diffuse Axonal Injury

Diffuse axonal injury affects nerve fibers, which can lead to a  disruption in nerve communication — affecting a person's physical and cognitive abilities.

[Diffuse Axonal Injury] Diffuse axonal injury, or DAI, is caused by the combination of acceleration, deceleration, and contact forces. Unlike hematomas and hemorrhages, where the brain damage involves bleeding, DAI affects individual nerve fibers. Nerve fibers are composed of a neuron body and an axon. Nerves function by sending signals from the neuron body down the axon to other nerves. When acceleration-deceleration forces are great enough, they produce a shearing force that severs the axons of nerve fibers, disrupting nerve communication. This disruption causes nerve cells to die and produces swelling in the brain. When the brain swells, pressure in the skull increases and can lead to complications such as restricted blood supply to the brain tissue and brain herniation.
Posted on BrainLine November 21, 2011. Reviewed June 1, 2018.

Used with permission from the Georgia Health Sciences University.