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Traumatic Brain Injury (TBI)


A traumatic brain injury (TBI) can be caused by a forceful bump, blow, or jolt to the head or body, or from an object that pierces the skull and enters the brain. Not all blows or jolts to the head result in a TBI.

Some types of TBI can cause temporary or short-term problems with normal brain function, including problems with how the person thinks, understands, moves, communicates, and acts. More serious TBI can lead to severe and permanent disability, and even death.

Some injuries are considered primary, meaning the damage is immediate. Other outcomes of TBI can be secondary, meaning they can occur gradually over the course of hours, days, or appear weeks later. These secondary brain injuries are the result of reactive processes that occur after the initial head trauma.

There are two broad types of head injuries: Penetrating and non-penetrating.

  1. Penetrating TBI (also known as open TBI) happens when an object pierces the skull (e.g., a bullet, shrapnel, bone fragment, or by a weapon such as hammer or knife) and enters the brain tissue. Penetrating TBI typically damages only part of the brain.
  2. Non-penetrating TBI (also known as closed head injury or blunt TBI) is caused by an external force strong enough to move the brain within the skull. Causes include falls, motor vehicle crashes, sports injuries, blast injury, or being struck by an object.

Some accidents such as explosions, natural disasters, or other extreme events can cause both penetrating and non- penetrating TBI in the same person.

Source: National Institute of Health (2023). Traumatic Brain Injury (TBI).