Subarachnoid haemorrhage

Question 1

Causes of spontaneous SAH

Answer 1

• intracranial aneurysm (saccular ‘berry’ aneurysms)

conditions associated with berry aneurysms:
- HTN
- polycystic kidneys
- Ehlers Danlos
- Coarctation of Aorta
- AVM
Pituitary apoplexy
Mycotic (infective) aneurysm

Question 2

Presenting symptoms in SAH

Answer 2

• sudden-onset ‘thunderclap’ occipital headache
• peaking in intensity within 1 to 5 minutes
• N+V
• meningism (photophobia, neck stiffness)
• coma
• seizures

Question 3

Why are ECG changes sometimes seen in SAH?

Answer 3

secondary to either autonomic neural stimulation from the hypothalamus or elevated levels of circulating catecholamines

• sometimes can show ST elevation

Question 4

INvestigation of suspected SAH

Answer 4

1. non-contrast CT head
2. LP if CT done >6hrs after symptom onset

Question 5

LP findings in SAH

Answer 5

xanthochromia - 12hrs post symptom onset
normal or raised opening pressure

Question 6

Imaging which will identify causative pathology

Answer 6

CT intracranial angiogram (to identify a vascular lesion e.g. aneurysm or AVM)

+/- digital subtraction angiogram (catheter angiogram)

Question 7

Management of confirmed SAH due to aneurysm

Answer 7

• supportive/ analgesia
• VTE prophylaxis
• reverse anticoagulation
• vasospasm is prevented using a course of oral nimodipine
• neurosurgery/interventional neuroradiology input for coiling

Question 8

Complications of SAH

Answer 8

re-bleeding
hydrocephalus
vasospasm
hyponatraemia (SIADH)
seizures