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Suspected cauda equina syndrome — MSRA MCQ

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Hardall topics relevant for this examSuspected cauda equina syndromeMSRA

A 42-year-old man contacts his GP practice with worsening low back pain after lifting a heavy box 2 days ago. The pain now radiates down the posterior aspect of his left thigh and calf. Since this morning, he has noticed numbness when wiping after opening his bowels and says that he can pass urine but no longer feels the normal urge to void until his bladder is very full. He has no fever, recent infection, cancer history, intravenous drug use or immunosuppression. He is walking independently. Examination shows left ankle plantarflexion 4+/5, with preserved knee extension and normal peripheral pulses. Anal tone is not assessed in the consultation. What is the most appropriate management now?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — Refer immediately via the local emergency pathway for assessment of cauda equina syndrome

Explanation lettering: C = shown as A · E = shown as C · A = shown as E

This patient requires immediate referral for suspected cauda equina syndrome (CES). The decisive combination is severe acute low back pain with radicular leg pain, new perineal sensory disturbance and new bladder dysfunction. His altered awareness of bladder filling is a new disturbance of urinary function; established painless retention or overflow incontinence is not required before emergency assessment is indicated. Mild unilateral plantarflexion weakness adds concern but is not needed to establish the referral threshold. NICE recommends immediate referral, using local pathways, for adults with severe low back pain radiating into a leg who develop new disturbance of bladder, bowel or sexual function, or new-onset perineal numbness. “Immediately” means assessment by the specialist service within hours, or faster if necessary. In primary care, the appropriate action is emergency referral rather than arranging community or outpatient imaging, because urgent imaging and potential decompression must be coordinated through the acute pathway. A is unsafe because outpatient MRI may delay definitive assessment. B is appropriate for some non-emergency spinal presentations, but not with CES red flags. D and E may be appropriate for uncomplicated mechanical low back pain with sciatica, but both disregard neurological red flags requiring emergency assessment.

Reference: NICE NG127: Suspected neurological conditions: recognition and referral — Recommendations for adults aged over 16 (Published May 2019; last updated October 2023) — https://www.nice.org.uk/guidance/ng127/chapter/recommendations-for-adults-aged-over-16 NICE NG127: Terms used in this guideline (Published May 2019; last updated October 2023) — https://www.nice.org.uk/guidance/ng127/chapter/terms-used-in-this-guideline NICE NG59: Low back pain and sciatica in over 16s — Recommendations (Published November 2016; updated December 2020) — https://www.nice.org.uk/guidance/NG59/chapter/recommendations