Subarachnoid Haemorrhage Flashcards
What is a SAH?
Spontaneous bleeding into the subarachnoid space, often catastrophic
What is the typical age range affected?
35-65
Where are the most common places to get a berry aneurysm?
Junction of posterior communicating artery with internal carotid, junction of anterior communication artery with anterior cerebral artery, bifurcation of middle cerebral artery
What are some less common causes of SAH?
Arterio-venous malformations, idiopathic
What are some risk factors for SAH?
HTN, known aneurysm, previous aneurysmal SAH, smoking, alcohol, FH, bleeding disorders
What are some risk factors for Berry aneurysms?
PKD, coarctation of aorta, Ehlers-Danlos syndrome, Marfan syndrome
What is the classic presentation of a SAH?
Sudden onset excruciating headache, thunderclap, typically occipital
What symptoms can follow the headache?
Nausea and vomiting, collapse, loss of consciousness, seizures, coma
What signs can be present?
Neck stiffness, Kernig’s sign, Brudzinski’s sign, retinal/subhyaloid/vitreous bleeds
What can suggest site of aneurysm?
Focal neurology at presentation
What test should you do?
Urgent CT - Star shaped sign
When should you consider doing a lumbar puncture?
If CT negative but history is very suggestive of SAH and ICP is normal
How long after headache onset should you do a lumbar puncture and why?
> 12h to allow breakdown of RBCs. Positive sample is xanthochromic (yellow)
What are some differential diagnoses?
Headache, migraine, meningitis, intracerebral haemorrhage, cortical vein thrombosis
Who should you refer to?
Neurosurgery
