Traumatic Brain Injury 1 Flashcards
Traumatic Brain Injury
An insult to the brain caused by an external force that may produce an altered state of consciousness, but results in impaired physical or cognitive function.
Causes and Risks for TBI
Most common cause is MVA’s, followed by assaults, sport injures and workplace accidents. Risk factors include being young or unemployed, male, low education, low SES and alcohol use.
Contact Force TBI
Head is still and receives a blow from a moving object.
Inertial Force TBI
Damage caused by sudden changes to the forces acting on the brain.
Acceleration Forces
Translational (forward/backwards), rotational (side to side) and angular (combination of translational and rotational).
Contusion
Focal damage to brain tissue and vessels, often on the surface of the brain (i.e. crests of the gyri) but can occur deeper.
Laceration
Tearing of the pia or arachnoid mater, with shredding of neurons on the surface of the brain as it rubs against the inside of the skull.
Coup and Contrecoup Injuries
Contusions occur at the point of impact (coup) but also on the part of the brain opposite to the point of contact (contrecoup) as a result of rebounding.
Shearing
A consequence of angular forces is shearing of neurons and blood vessels. Neurons stretch, bend and break as a result of the forces, which causes the neurons to die.
Diffuse Axonal Injury
Results when the head comes to a rapid stop from high speed. Axons tear and stretch, resulting in retraction balls and swelling of the damaged neurons. This causes diffuse damage.
Concussion
Caused by a blow to the head or angular forces. Mild concussion has no LOC and mild confusion. Classic concussion results in LOC at the instant of trauma, rigidity and possibly seizures.
Epidural Haematoma
Blood filled swelling that occurs between the brain and the skull.
Subdural Haematoma
Blood filled swelling that occurs between the meninges (dura mater) and the brain.
Intracerebral Haematoma
Blood filled swelling that occurs within the brain tissue (often in the frontal or temporal lobes).
Secondary Injuries of Closed Head Injuries
Increased intracranial pressure, brain swelling (hydrocephalus), hypoxia, fever and infection.