Brain Haemorrhages Flashcards
How can you classify brain haemorrhages?
Extra-axial
Intra-cerebral
What is an extra-axial haemorrhage?
When bleeding occurs within the skull but outside the brain
What is an intra-cerebral haemorrhage?
Bleeding within the brain itself
Inter-parenchymal
Name the three types of extra-axial haemorrhage?
Epi-dural
Sub-dural
Sub-arachnoid
What is an epi-dural haemorrhage?
Bleeding in between the dura and the skull bone
Usually the dura is stuck tightly to the skull, in an epi-dural haemorrhage it is peeled away as the blood fills
What causes an epi-dural haemorrhage?
Usually a skull fracture that ruptures the middle meningeal artery
Trauma usually
What would an epi-dural haemorrhage look like on a head CT?
A classic convex shape on the edge of the brain
This is the haematoma
What is a haematoma?
A localised collection of blood outside blood vessels
AKA a bruise
What are the layers of the meninges from inside to out?
PAD out
Pia mater
Arachnoid
Dura mater
Clinical features of an epi-dural haemorrhage?
Lucid interval: for a period of time (a few hours to a few days) after the injury the person will appear to be fine and functioning normally
After this though they have:
- increasingly severe headache
- vomiting
- confusion
- unconsciousness, fits, coma
- death due to coning
What is a lucid interval and why does it occur?
For a period of time after an injury that has resulted in an epi-dural haemorrhage, the patient appears to function normally
Because initially the volume of blood in the haematoma is not sufficient to cause any symptoms, as the blood builds up it puts pressure on the brain, affecting its function
What is a sub-dural haemorrhage?
Bleeding into the space under the dura
So between the dura and the arachnoid membrane
What happens to the brain inside the skull when you hit your head really hard?
When the head is hit it moves rapidly (obviously)
The brain is heavy so it moves backwards and forwards slower than the head does
This causes the brain to crash against the skull, bruising it
It can also cause the tearing of the bridging blood vessels that cross the subdural space
What causes a sub-dural haemorrhage?
A head injury
When the brain moves out of sync with the skull the bridging vessels that cross the sub-dural space tear, causing bleeding into the subdural space
Common in elderly who have falls
Which people are more susceptible to sub-dural haemorrhages?
Elderly
Alcoholics
Because they have atrophic (shrunken) brains
Their bridging vessels are more likely to tear
They get chronic haematoma
What is chronic haematoma?
Occurs in people with small sub-dural haemorrhages
They get signs of dementia and other symptoms as a result
Treatable
Clinical features of sub-dural haemorrhage?
Headache Fluctuating consciousness Physical or intellectual slowing Confusion Drowsiness
These often develop a long time (months) after injury
How do you treat an epi-dural haemorrhage?
Drain the blood
What is coning?
Herniation of the brain downwards, compressing the brainstem
Very dangerous as it causes respiratory depression, death
Why do the symptoms of a sub-dural haemorrhage take months to manifest?
Because at the time of the injury they get a bit of pain, but a clot soon forms and they’re able to go on normally
8-16 weeks later the body tries to break the clot down
The breaking up of the clot releases fibrin
This raises the oncotic pressure of the blood in the haematoma
Water is drawn into the clot, raising the intra-cranial pressure
Compression of brain = symptoms
Treatment of a sub-dural haemorrhage?
Surgical removal of the haematoma
What is a sub-arachnoid haemorrhage?
Bleeding into the sub-arachnoid space
Between the arachnoid and the pia mater
What causes a sub-arachnoid haemorrhage?
Head injury
Spontaneous:
- berry aneurysms of circle of willis
- congenital arteriovenous malformations
The circle of willis is in the subarachnoid space
Clinical features of a sub-arachnoid haemorrhage?
Sudden onset severe ‘thunderclap’ headache
Vomiting
Reduced consciousness
Photophobia
