Cerebrovascular Neurosurgery
What you must own
Understand aneurysmal subarachnoid haemorrhage: presentation (thunderclap headache), investigation (CT within 6 hours is highly sensitive; lumbar puncture for xanthochromia if CT negative), grading (WFNS, Hunt and Hess), and complications (rebleeding, vasospasm/delayed cerebral ischaemia days 3-14, hydrocephalus, hyponatraemia). Management: early securing of the aneurysm (clipping or coiling), nimodipine, and management of vasospasm.
Arteriovenous malformations: Spetzler-Martin grading (size, eloquence, venous drainage) and treatment options (microsurgery, embolisation, radiosurgery, observation).
Cavernous malformations: popcorn appearance on MRI, low haemorrhage risk, often observed.
Moyamoya disease: progressive stenosis of distal internal carotid arteries with collateral "puff of smoke"; revascularisation surgery.
Ischaemic stroke: thrombectomy for large-vessel occlusion within the appropriate window.
Traps
Questions test that a negative CT does not exclude SAH (lumbar puncture for xanthochromia) and that vasospasm peaks around days 3-14, not immediately. Another trap: confusing haemorrhagic transformation with rebleeding.
Rule of thumb
SAH: CT first; if negative and suspicion persists, lumbar puncture for xanthochromia. Secure the aneurysm early; watch for vasospasm in the second week.
Worked example
A patient with a sudden severe headache has a normal CT at 12 hours. Because CT sensitivity declines with time, a lumbar puncture is performed and shows xanthochromia, confirming subarachnoid haemorrhage.