Flashcards in W19-L11: Traumatic head and spinal cord injury Deck (26):
Direct effects of trauma can be seen in
SCALP – lacerations
SKULL – fractures
MENINGES - vascular injury, lacerations
BRAIN/CORD - contusions, lacerations, diffuse axonal injury (DAI) , diffuse vascular injury
T/F :Central nervous system (CNS) injury is the leading cause of death in people < 45 years of age in Western countries.
T/F: CNS injury causes
1% of all deaths
30% of deaths from trauma
50% of deaths due to motor vehicle accidents
direct disruption of tissue
movement and compression of neural and vascular structures within bony confines
Secondary effects of traumatic injury
Cerebral swelling (raised ICP)
Features of Skull fractures, types and where they occur
Tend to radiate from point of impact, can be depressed, can be open, closed, comminuted (splintering) and can be basal
Coup and contrecoup
Coup: at impact site
Contrecoup: Occur when head is not immobilised at the time of injury and involves the opposite side of the brain
Where does the sterotypic contusion occur and what is it called?
Base of brain known as basal contusions
Healed cerebral contusions
Brain contusions occur at the tips of gyri, and the gyri and sulci become more pronounced as lost tissue is not replaced
Penetration by foreign body or skull fragments
Kinetic energy imparted by a bullet is determined by the projectile velocity
Vulnerable site of tearing due to sufficient energy transfer
Diffuse forms of brain injury
Diffuse axonal injury, diffuse vascular injury
Build up of axonal material that is being transported down the axon (not immediate)
Long term effects of diffuse axonal injury
Increased ventricular size, thinned corpus callosum
Cord-compressive acute traumatic injury
cord tissue is squeezed both proximally and distally by impaction "toothpase effect"
dilated ventricles compresses brain tissue eg blockage of drainage from fourth ventricle
Chronic traumatic encephalopathy
-Brain atrophy due to neuronal loss.
-Abnormal deposition of Tau protein.
-Often diffuse deposition of A-beta plaques in cortex
Initial response to an expanding brain lesion
expulsion of as much CSF and venous blood as possible. After that, intracranial pressure starts to rise.
Where do Herniations of brain tissue occur?
Through Dural openings
Two subtypes of cerebral oedema
VASOGENIC – due to blood-brain barrier disruption with increased vascular permeability, mainly involves white matter
CYTOTOXIC – increased INTRAcellular fluid secondary to neuronal, glial or endothelial cell membrane injury. Grey and white matter. Nastier than vasogenic
vessels are fixed so diencephalic herniation causes tearing of these vessels causes brainstem haemorrhages
Cingulate gyrus under falx cerebri
Medial temporal lobe under the tentorium cerebelli