Space Occupying Lesions Flashcards
What forms the roof over the pituitary fossa?
Diaphragm Sellae
What lays over the cerebellum separating it from the cerebrum?
Tentorium Cerebelli
What midline structure seperates the left and right cerebral hemispheres running from the ethmoid bone to the posterior occipital protuberance?
Falx cerebri
What is hydrocephalus?
Excessive Production, obstruction or inadequate resorption of CSF.
Extradural haemorrhage
Between bone and dura
Extradural can also be known as?
Epidural
What artery if ruptured commonly results in an extradural haemorrhage?
Middle Meningeal Artery
Subdural Haemorrhage
Between the dura and arachnoid matter
What if ruptured commonly results in a subdural haemorrhage?
Cerebral veins - falls in the elderly
Subarachnoid haemorrhage
Bleed into the CSF of the subarachnoid space
What if ruptured would lead to a subarachnoid haemorrhage?
Circle of willis or congenital aneurysm
A single abscess is likely to be due to?
Local extension e.g mastoiditis dental infection
Direct Implantaion e.g. skull fracture
List some causes of a local extension abscess.
Mastoiditis
Chronic ottitis media
Paranasal sinusitis
Dental infection
Multiple abscesses are usually due to.
Haematogenous spread.
Bronchiectasis, Endocarditis, IV drug abuse
What do abscesses look like?
Central Necrosis and a fibrous capsule
Surrounded by oedema
How is an Abscess diagnosed?
CT MRI
Aspiration for culture and treatment
What is the golden rule of trauma?
Smaller the contact time the larger the force is applied.
What is the primary damage in brain trauma?
Irreversible injury to neurones
Is primary damage treatable?
No it is only preventable through safety measures like wearing a helmet etc
What is secondary damage in brain trauma?
Potentially treatable haemorrhage oedema etc
Why do Skalp lesions present an issue?
As they can present route of entry for infection
If a skull fracture is straight and sharp it is a…
Linear fracture
If a linear fracture crosses a suture it is known as a..
Diastatic
Compound fractures are associated with…
Full thickness lacerations
Base of skull fractures are all….
Compound fractures
Depressed fractures present a risk because..
They allow direct infection of the brain
Surface contusion and laceration of the brain is due to..
Compression of brain tissue
Basically bruising of the brain tissue
What areas of the brain are most commonly affected by contusion?
Lateral surfaces of the hemispheres
Underneath the temporal and frontal lobes
Contra coup is what?
Contusion to the brain on the opposite side to the trauma.
Contracoup involves less force than Coup.
False it involves more force an CSF has shifted to side of trauma thus reducing cushioning.
Damage is worse.
Coup is what?
Contusion to the brain tissue of the side of the trauma.
When does diffuse axonal injury occur?
At the moment of injury
Why does diffuse axonal injury occur?
Shearing forces transect neurones
What is the affect of diffuse axonal injury?
Reduced Consciousness and coma
A traumatic extradural haemotoma is usually due to what?
Tempero-Parietal Fracture
Tearing Middle Meningeal artery
What is the timeline in extradural haemorrhage ?
Acutely - very little damage
Chronic - Midline shift compression and herniation
Acute subdural haematoma due to stretching of the bridging veins is not a medical emergency. T/F
False it has a 60% fatality rate
How will a chronic subdural haematoma will appear on examination?
Liquefied blood and yellow tinged fluid forming a pseudomembrane.
What will someone with a Subarachnoid haemorrhage present with?
Sever thunderclap headache
Loss of consciousness
Why would someone with a subarachnoid haemorrhage present with a thunderclap headache?
Irritation of the meninges - supplied by the facial nerve
A subarachnoid haemorrhage will show what on initial CT scan?
Blood in the basal cisterns
