Primary and Secondary Damage
Damage that occurs at the time of actual impact. There are many types of primary damage that may occur. These include:
- Coup-Contrecoup Injury- damage to the brain on both sides: the side that received the initial impact (coup) or blow and the side opposite the initial impact (countrecoup). This occurs when the force of the initial blow is great enough to cause brain damage at the site of initial impact between the skull and brain and is also great enough to cause the brain to move in the opposite direction and hit the opposite side of the skull, causing damage at that site.
- Skull Fracture- breaking of skull bone
- Contusion/Bruise- discoloration and/or swelling at the location of actual impact or at the point or points where the force of the blow has driven the brain against the skull’s bony ridges
- Hematoma/Blood Clot- swelling or mass of blood between the skull and the brain or inside the brain itself
- Laceration- tearing of brain tissue and/or blood vessels, caused by forceful rotation of the brain across the skull’s bony ridges
- Nerve Damage (Diffuse Axonal Injury)- shearing or tearing of white matter in connecting nerve fibers in the brain; can cause unconsciousness and/or coma
Damage that occurs over time after the actual brain injury; may include infection, hypoxia (oxygen deprivation), edema (brain swelling), elevated intracranial pressure, infarction (death of brain tissue which results in loss of blood supply to that region of the brain), and hematoma (focal area of bleeding in the skull due to tearing of blood vessels). Many traumatic brain injuries result in multiple types of primary and secondary damage.
Diffuse vs. Localized Damage
Localized damage occurs in a specific location. Localized damage is commonly associated with an injury in which the head strikes or is struck by an object. This usually occurs following an open/penetrating traumatic brain injury.
Diffuse damage occurs over a widespread area. Diffuse damage is commonly associated with acceleration/deceleration injuries, in which the head does not necessarily contact anything, but brain tissue is damaged. This often occurs in a closed traumatic brain injury.
Many traumatic brain injuries cause both localized and diffuse damage.
Scroll down to see descriptions of different types of open and closed head injuries.
On the right-hand side of the webpage under “Video Library,” there is a video called “What Happens?”