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iatroX Rounds #2

Thursday, 25 June 2026·Neurologymoderate

The clues

  1. 1

    A 44-year-old woman presents to A&E with sudden severe headache.

  2. 2

    The headache came on abruptly, described as the 'worst of her life', while she was at work.

  3. 3

    She has a history of treated hypertension but is otherwise healthy.

  4. 4

    On examination she is photophobic and vomits once in the department.

  5. 5

    A non-contrast CT head shows hyperdensity within the basal cisterns.

  6. 6

    Lumbar puncture performed 12 hours after symptom onset reveals xanthochromia.

the diagnosis
Subarachnoid haemorrhage

Subarachnoid haemorrhage is bleeding into the subarachnoid space, most often due to ruptured berry aneurysm. Thunderclap headache, photophobia and meningeal signs should raise clinical suspicion, especially when CT shows blood in the cisterns and lumbar puncture demonstrates xanthochromia.

  • Thunderclap headache (sudden and severe)
  • Photophobia and vomiting
  • Xanthochromia on lumbar puncture
  • Often in patients with hypertension or vascular risk
pearl. Xanthochromia after 12 hours is diagnostic and distinguishes SAH from a traumatic lumbar puncture.

more Neurology rounds

A 62-year-old man presents with progressive weakness in his right hand that started four months ago.#27A 32-year-old man presents with a two-day history of progressive weakness and tingling in both of his feet and legs.#24A 26-year-old woman presents to her GP with a diffuse, daily headache that has been present for the last month.#20A 32-year-old woman presents with a three-week history of numbness and tingling in both legs and persistent fatigue.#17

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for education and entertainment. not medical advice.