Traumatic Head and Spinal Injury and Raised Intracranial Pressure Flashcards
What are some secondary effects of traumatic brain injury?
Ischaemia, Hypoxia, Cerebral swelling (raised ICP), Infection, Epilepsy
What is a comminuted skull fracture?
where there is splintering of the bone
What causes an extra dural haematoma?
rupture of the middle meningeal artery
What causes a subdural haematoma?
rupture of the subdural veins
Who is more at risk of extra dural haematomas and who is more at risk of subdural haematomas?
young people are more at risk of extra dural and older people are more at risk of subdural
What is a contusion?
haemorrhagic necrosis (bruise)
At what sites do contusions usually occur?
at the site of impact, on the opposite side to the site of impact and at the base of the brain (inferior frontal and temporal lobes)
Which cranial nerve is often damaged due to contusions?
the olfactory nerve
What does an old cerebral contusion look like macroscopically?
at the tips of the gyri the brain tissue collapses and is yellow with haemosiderin stains
What is a traumatic cerebral haematoma?
an intracerebral haemorrhage
What does a diffuse axonal injury look like macroscopically?
spotty haemorrhages on the corpus callosum, thin white matter generally, brain atrophy, enlarged ventricles
What is hydrocephalus?
enlarged ventricles - can occur if old blood blocks the exit foramina for CSF
What is chronic traumatic encephalopathy?
frequent injuries leading to brain atrophy, abnormal deposition of Tau protein and deposition of plaques
What is the initial response to an increase in ICP?
expulsion of as much CSF and venous blood as possible
What are some potential causes of raised ICP?
trauma, tumour, infarction, haemorrhage, infection, cerebral oedema, overproduction of CSF, obstruction to flow or absorption of CSF
What are the two main types of cerebral oedema and what is the difference?
vasogenic and cytotoxic
vasogenic is due to disruption of the blood brain barrier and can be treated with steroids
cytotoxic is due to increased intracellular fluid and cannot be treated with steroids
What are the common sites of herniation with raised ICP?
cingulate gyrus pushed underneath the falx cerebri, medial temporal lobe is pushed through the tentorium cerebelli, cerebellar tonsils are pushed into the spinal canal
What is a subfalcine herniation?
when the cingulate gyrus is pushed underneath the falx cerebri
What is an uncinate herniation?
when the medial temporal lobe is pushed through the tentorium cerebelli
What is a tonsilar herniation?
when the cerebellar tonsils are pushed into the spinal canal
What is the result of a subfalcine herniation?
may result in an infarct of the corpus callosum
What is the result of an uncinate herniation?
CNIII compression which causes ipsilateral pupil dilation, compression of reticular activating system causing loss of consciousness, PCA compression which affects visual cortex, compression of cerebral peduncles which causes hemiparesis
What is the result of a tonsilar herniation?
compression of the respiratory centres in the medulla - fatal
