Intracerebral Haemorrhage Flashcards
In a subarachnoid haemorrhage there is bleeding into where? What structures are found here that can disrupted by this pathology?
Subarachnoid space - arteries that supply the brain, and the BBB
Where is the subarachnoid space found?
In between the arachnoid and pia mater
In subarachnoid haemorrhage, a pool of blood forms under the arachnoid mater. What effect does this have?
Causes increased ICP and prevents blood from flowing into the brain
A subarachnoid haemorrhage can occur without an underlying cause, or it can occur as a result of what 3 things?
Trauma, aneurysm, AVM
Why is trauma likely to cause a subarachnoid haemorrhage?
Arteries in the subarachnoid space are unsupported and can easily rupture
What is the most common underlying cause predisposing to a SAH?
Berry aneurysm
What are some diseases which can predispose to developing a Berry aneurysm?
PCKD, Marfan’s
A Berry aneurysm can rupture if there is what?
Raised ICP
How can an AVM lead to a SAH?
Abnormally high pressure in veins leads to rupture
Why does SAH cause vasospasm?
It is an attempt to increase BP to increase cerebral blood flow (since SAH blocks the flow of blood to downstream tissues)
Haemorrhaging blood in SAH can irritate the meninges, what is the clinical outcome of this?
It leads to inflammation and scarring which obstructs the outflow of CSF and causes hydrocephalus
What is the most common presenting feature of a SAH?
Thunderclap headache (often described as the worst ever headache)
Apart from headache, what are some other presenting features of SAH?
Neck stiffness, vomiting, vision changes, confusion/decreased conscious level/collapse, focal neurological deficit
What may be seen on fundoscopy of a patient with SAH?
Retinal or vitreous haemorrhage
What are some differentials of a presentation of SAH?
Migraine, benign coital cephalgia, exercise induced cephalgia
What are the main red flags for SAH?
‘Worst ever headache’, neck stiffness and onset with exertion
What are the 3 main investigations for SAH?
CT brain, LP, cerebral angiography
When may a brain CT not pick up a SAH?
If its been greater than 3 days since the onset
When is it safe to perform an LP on a patient with suspected SAH?
If the patient is alert, has no focal neurological deficits and no papilloedema / after a normal CT scan
What are two results of an LP which are positive for SAH?
Red (fresh blood) or yellow (xanthochromia, bilirubin breakdown product, older blood)
If a CSF sample comes out yellow, apart from xanthochromia what is another reason for this?
Traumatic tap - when the needle hits an epidural vein on entering
What is the gold standard investigation for SAH?
Cerebral angiography
What may cause an aneurysm to be missed on cerebral angiography?
Vasospasm
What techniques are used to increase the sensitivity of cerebral angiography?
CT and MR angiography
