There are many events which can result in brain injury, such as a blow to the head, the head striking an object, a penetration of the skull such as in a gunshot, or particularly relevant to auto accident cases, by rapid acceleration and deceleration of the brain.
In each of the above events, the brain can be injured both by impact and rotational or shear forces. While it is the common conception that impact damage comes from blows to the head and shear damage from whiplash forces, both types of damage can occur from either mechanism.
Impact damage tends to be focal, meaning concentrated in specific parts of the brain, whereas shear injuries tend to be diffuse, meaning occurring throughout widespread portions of the brain. Thus, the term “Diffuse Axonal Injury” meaning widespread injury to the axons, the long thin portion of the neuron.
Mechanisms of Brain Injury:
- A Blow to the Head;
- The Head Hitting an Object;
- A Rapid Acceleration/Deceleration Movement, such as Whiplash.