Brain injuries are often classified as primary injury and secondary injury.
Primary brain injuries occur at the moment of impact and can affect the entire brain or its specific lobes.
The secondary injury refers to the brain undergoing a delayed trauma where it swells against the skull, reducing the flow of oxygen-rich blood.
There are five (5) major types of traumatic brain injuries:
1. Concussion
Concussions result from sudden movements that cause the brain and head to dramatically move back and forth.
This can lead to the brain bouncing around in the skull creating chemical changes and brain cell damage.
Concussions are often described as a “mild” brain injury because they usually are not life-threatening, but the effects can be serious.
2. Contusion
Contusions are bruises on specific areas of the brain resulting from an impact on the head.
Contusions are classified as coup or contrecoup injuries.
Coup contusions refer to when the brain is injured directly at the area of impact.
In contrecoup injuries, the bruise occurs on the opposite side of impact.
3. Diffuse Axonal Injury
Diffuse axonal injuries refer to the stretching and tearing of the brain’s nerve cells at the cellular level.
Axons, which connect individual nerve cells throughout the brain, become damaged when the brain quickly moves back and forth inside the skull.
Diffuse axonal injury disrupts the brain’s ability to transmit information and can induce irregular bouts of sleepiness.
4. Traumatic Subarachnoid Hemorrhage
Traumatic subarachnoid hemorrhaging is a condition where bleeding occurs in the space surrounding the brain.
The bleeding occurs when the injury causes the brain’s small arteries to break.
The brain is normally cushioned and protected by cerebrospinal fluid, and blood entering this space can lead to severe headaches, blurry vision, permanent brain damage, and even death.
5. Hematoma
A hematoma is a blood clot that forms when one of the brain’s blood vessels ruptures.
Blood then escapes the bloodstream and thickens and clots.
This clotting can affect the brain’s dura, the dura lining, and deep within the brain tissue itself.
These clots can press against the brain causing confusion, loss of consciousness, and seizures.