Subarachnoid Haemorrhage Flashcards
What is the major cause of a subarachnoid haemorrhage?
Rupture of saccular aneurysms 80%
What is a less common cause of subarachnoid haemorrhage?
rupture of arteriovenous malformations 15%
When does subarachnoid haemorrhage display gender preference?
Only slight female preference (3:2) >45 years
Could indicate women more susceptible post-menopause
Where are saccular aneurysms most common?
Junction of the posterior communicating with internl carotid
Anterior communicating with anterior cerebral artery of bifurcation of the MCA
Where are saccular aneurysms most common?
Junction of the posterior communicating with internl carotid
Anterior communicating with anterior cerebral artery of bifurcation of the MCA
What percentage of subarachnoid haemorrhage cases have multiple aneurysms?
~15%
What other conditions are subarachnoid haemorrhages associated with?
Polycystic kidney
Coarctation of the aorta
Ehlers-Danlos syndrome
What is the classic symptom that is a red flag for subarachnoid haemorrhage?
Development of an instantaneous, devastating headache without warning
What symptoms typically follow the initial headache of subarachnoid haemorrhage?
Vomiting
Collapse
Seizures
Coma
What signs can be found in subarachnoid haemorrhage?
Neck stiffness/Kernig’s sign
CN palsies
What percentage of patients presenting with a ‘thunderclap’ headache have subarachnoid haemorrhage?
25%
Most are idiopathic, rest are meningitis, migraine, intracerebral bleeds, cortical vein thrombosis
Why should we be particularly concerned about any sudden headache?
Because aneurysms can have warning leaks
The least symptomatic subarachnoid haemorrhages are the most successful in terms of surgical intervention, hence we should always be on the lookout
What is the investigation of choice in subarachnoid haemorrhage?
CT
Detects >90% of SAH within the first 48 hours
When should you do an LP in subarachnoid haemorrhage, and what will it show?
If CT is -ve despite strong clinical suspicion, and no contraindications to the LP
Should be done at least 12 hours after the onset of symptoms though
Why should we be particularly concerned about any sudden headache?
Because aneurysms can have warning leaks (sentinel headaches)
The least symptomatic subarachnoid haemorrhages are the most successful in terms of surgical intervention, hence we should always be on the lookout
When should you do an LP in subarachnoid haemorrhage?
If CT is -ve despite strong clinical suspicion, and no contraindications to the LP
Should be done at least 12 hours after the onset of symptoms though
What will you find in CSF in subarachnoid haemorrhage?
Uniformly bloody early on
Becomes xanthomorphic (yellow) later on due to breakdown products of Hb (bilirubin)
Would a uniformly bloody LP or a xanthomorphic LP be more indicative of a subarachnoid haemorrhage?
Xanthomorphic
Blood in the CSF could be from the LP procedure itself, where bilirubin in CSF could not
Why should we be particularly concerned about any sudden headache (especially with neck and/or back pain)?
Because aneurysms can have warning leaks (sentinel headaches)
The least symptomatic subarachnoid haemorrhages are the most successful in terms of surgical intervention, hence we should always be on the lookout
Would a uniformly bloody LP or a xanthomorphic LP be more indicative of a subarachnoid haemorrhage?
Xanthomorphic
Blood in the CSF could be from the LP procedure itself, where bilirubin in CSF could not
Would a uniformly bloody LP or a xanthomorphic LP be more indicative of a subarachnoid haemorrhage?
Xanthomorphic
Blood in the CSF could be from the LP procedure itself, where bilirubin in CSF could not
Should HTN be managed in the acute subarachnoid haemorrhage setting?
No
High BP increases cerebral perfusion
What blood pressure should be aimed for in the setting of subarachnoid haemorrhage?
> 160mmHg
What drug is useful in the setting of subarachnoid haemorrhage for controlling vasospasm?
Nimodipine
Is endovascular coiling or surgical clipping more effective in the treatment of subarachnoid haemorrhage?
Endovascular clipping
What is the trade-off when it comes to endovascular clipping in the setting of subarachnoid haemorrhage?
Increased chance of rebleeding (despite increased chance of survival)
Should surgical intervention be done before angiography in the setting of subarachnoid haemorrhage?
No
CT/catheter angiography should be performed first, to determine whether there are single or multiple aneurysms that require management
What are some common complications of subarachnoid haemorrhage?
Rebleeding
Cerebral ischaemia due to vasospasm (treat with nimodipine)
Hydrocephalus due to blockage of aranchoid granulations, requires a ventricular or lumbar drain
What are some poor prognostic markers for subarachnoid haemorrhage?
Drowsiness (37% mortality)
Hemiplegia (71% mortality)
Coma (100% mortality)
What are some poor prognostic markers for subarachnoid haemorrhage?
Drowsiness (37% mortality)
Hemiplegia (71% mortality)
Coma (100% mortality)
What agent is nimodipine?
Dihydropiridine calcium channel blocker
