Brain Injury

Primary - happen at the time of accident Sencondary - occur as the result of events following the accident. Missile/Non-missile.

THey are the result of rapid acceleration and decelerations which cause the brain to move in the skull causing it to collide with bony prominences

The size and velocity of missile.

Scalp and skull lesion Cerebral contusion Diffuse axonal injury

They are good indicators of the severity of injury but skull fractures can occur with no brain injury and brain injury can occur with no skull fracture

Collision of brain with skull prominences. Characteristic distribution Commonly on crest of gyri, into white mater

Shear forces result in widespread axonal injury, spectrum of severity common cause of coma in patien with no intercranial haematoma, vasogenic oedema

Common cause of deterioration after luciod period Intracranial haematomas - extradural and intral dural, burst lobe

Between skull and dura, rupture of middle meningeal artery leads to midline shift, tentorial herniation and midbrain compression

Caused by rupture of the bradging veins that cross the subdural space. Also caused by multiple cerebral contusions.

Subdural and intercranial haematoma plus cerebral contusions. Suggests severe disease.

Caused by defective BBB which leads to extravasation of water, sodium and proteins. Occurs around areas of contusion and haematoma. It is congestive when it is both hemispheres.

Occurs adjacent to area with haematoma or contusion and is the result of raised ICP. Occurs 60-70% of fatal head injuries.

Oxygen and nutrient supply and demand mismatch

Anaerobic respiration and electrical failure