PDPH with Cranial Nerve Palsy — FRCA Final MCQ

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ModerateRegional AnaesthesiaPDPH with Cranial Nerve PalsyFRCA Final

A 38-year-old man (ASA I, 75 kg) undergoes knee arthroscopy under spinal anaesthesia. In recovery he develops severe headache, worse on sitting, relieved lying flat, with bilateral 6th cranial nerve palsies. The most likely diagnosis is:

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Correct answer: B — Post-dural puncture headache with cranial nerve involvement

Post-dural puncture headache with bilateral 6th (abducens) cranial nerve palsies is a recognised complication of CSF leak following dural puncture. The headache is characteristically postural (worse upright, better supine). CSF leak reduces intracranial CSF volume, causing brain sagging and traction on the 6th cranial nerve (the longest intracranial course, most susceptible to stretching). This causes bilateral lateral rectus weakness and diplopia. Treatment: epidural blood patch (success rate 70-90%). 6th nerve palsy usually resolves within 6 months.

Reference: RCOA – 2023 – Regional anaesthesia complications; Sachs A – 2014 – PDPH review