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LP xanthochromia — SCE Neurology MCQ

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HardNeurological InvestigationsLP xanthochromiaSCE Neurology

A 61-year-old presents 18 hours after abrupt occipital headache, vomiting and transient collapse. Non-contrast CT is reported normal. Lumbar puncture performed at the appropriate interval shows bilirubin-positive xanthochromia. He is haemodynamically stable with no focal deficit. What is the next investigation?

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Correct answer: D — CT angiography without delay to identify the vascular cause

A CT performed more than 6 hours after symptom onset does not reliably exclude subarachnoid haemorrhage, so lumbar puncture is appropriate when suspicion remains. Bilirubin-positive xanthochromia confirms the diagnosis in this clinical context. NICE then recommends CT angiography without delay to identify an aneurysm or other vascular cause and guide neurovascular management. Repeating non-contrast CT or lumbar puncture would delay definitive imaging. MRI may provide additional information in selected circumstances but is not the immediate vascular test specified after confirmed SAH.

Reference: NICE NG228, subarachnoid haemorrhage caused by a ruptured aneurysm: https://www.nice.org.uk/guidance/ng228/chapter/Recommendations