Diffuse Axonal Injury: Mechanism for Injury

https://www.youtube.com/watch?v=4nzojIcPBG0

To understand how a brain can be injured by various physical forces, it is first necessary to understand its composition and nature. This video demonstrates its fragility and susceptibility to damage from relatively gentle pressure.

Due to the brain's high fat and water composition, it is actually possible to pull it apart like bread dough. With enough force, axons can be injured by being stretched or sheared (i.e., diffuse axonal injury). Research suggests that rotational forces may result in a higher risk of DAI.

From Charles Whitman: Up Against All Odds:

When angular acceleration and deceleration are present, more damage can occur since regions of the brain will move at different speeds and arc or twist, resulting in the increased possibility of shearing and tearing. Because the skull and brain are tethered, studies have demonstrated that the tangential components can "change the angular momentum of the brain about its mass center, causing rotation." So, "angular acceleration of the skull is not required to cause angular acceleration of the brain"--another reason DAI commonly occurs.