Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
2 min synopsisUK scopeSources checked 13 Sept 2026Clinical review pending
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Acute cauda equina compression
New urinary-flow sensory change, difficulty initiating micturition, saddle or genital sensory loss, bowel or sexual dysfunction, or severe progressive bilateral weakness with back or radicular pain may indicate CES.
Action: Refer immediately to a hospital with emergency MRI, document onset and progression, request MRI as soon as possible and within four hours of the radiology request, keep the patient nil by mouth, and refer confirmed compression immediately to spinal surgery.
Synopsis
Localise acute disc-related root, cord and cauda-equina deficits, activate the current England emergency MRI pathway when appropriate, and select decompression without routine fusion.
Localise before labelling: a single lumbar root causes dermatomal pain, myotomal weakness and reflex change; cauda equina compression adds sacral sensory, bladder, bowel or sexual dysfunction; cervical/thoracic compression adds upper-motor-neuron signs.
The March 2026 GIRFT pathway mainly addresses CES from a large lumbar disc; it warns that no single symptom, sign or MRI alone defines the clinical syndrome.
New or deteriorating CES symptoms within fourteen days require immediate referral for emergency MRI, obtained as soon as possible and within four hours of the radiology request.
Key red flags
Recent onset or deterioration of urinary initiation or flow sensation, perineal or genital sensation, rectal fullness or sexual function triggers the emergency CES pathway.
A normal post-void residual below 200 mL, preserved anal tone or other negative physical test does not exclude CES when positive subjective symptoms persist.
Rapidly progressive or severe motor weakness needs prompt MRI and spinal review even without CES, while cervical or thoracic long-tract signs imply cord rather than lumbar-root disease.
Fever, cancer, immunosuppression, anticoagulation, trauma or recent spinal procedure broadens the cause beyond disc and changes imaging and treatment.
Single-root deficit
Dermatomal pain or numbness with myotomal weakness and a reduced corresponding reflex supports radiculopathy from a lateral disc.
Incomplete cauda equina syndrome
Altered urinary sensation or initiation, saddle change or sexual dysfunction with preserved voluntary voiding marks a time-sensitive sacral-root syndrome.
CES with retention
Painless retention, overflow incontinence and loss of bladder sensation indicate advanced dysfunction but do not remove potential benefit from decompression.
Reasoning priorities
01
Emergency lumbar MRI for suspected CES
Confirm or exclude cauda-equina compression and identify the responsible disc or alternative surgical lesion.
Obtain as soon as possible and within four hours of request under GIRFT. MRI supports anatomy, but CES remains a clinical-radiological diagnosis requiring concordance.
Worked reasoning
Worked caseIncomplete CES from a large lumbar disc
A patient has one day of bilateral sciatica, saddle numbness and altered urinary-flow sensation but can still void.
Context: timestamp every symptom, record lower-limb MRC power and sensation, ask directly about bladder, bowel, perineal and sexual function, and use bladder scan only as an adjunct.
Reasoning: identify recent incomplete CES despite preserved voiding; refer immediately to emergency MRI, keep nil by mouth, and do not delay scanning for a pre-MRI spinal opinion.
Outcome: acquire MRI as soon as possible and within four hours of request; when cauda-equina compression is confirmed, refer immediately for time-sensitive decompression and document any delay.
Verification: after surgery, reassess power, perineal sensation, bladder emptying, bowel and sexual function; mobilise when safe and refer persistent deficits to spinal-cord-injury, urology and rehabilitation services.
National guidance is shown before implementation-dependent detail. Apply principles in context and verify current guidance when a decision affects care. Source check completed 13 Sept 2026; clinical approval remains outstanding.
NHS England GIRFT national suspected cauda equina pathwayNational Suspected CES Pathway, issued February 2023 and updated through March 2026; pages 5–14 read 13 September 2026. It covers suspected and MRI-proven CES, principally from large lumbar disc prolapse, and supplies England best-practice referral, MRI, surgery and postoperative-care timings. Chapter-specific use: acute disc prolapse with neurological deficit.
WFNS lumbar disc herniation diagnostic recommendationsWFNS Spine Committee systematic review and Delphi recommendations, World Neurosurgery X 2024; examination, MRI and motor-deficit sections read 13 September 2026. International professional consensus supports early imaging for motor deficit and MRI as the appropriate non-invasive confirmation test. Chapter-specific use: acute disc prolapse with neurological deficit.
WFNS lumbar disc herniation surgery recommendationsWFNS Spine Committee systematic review and Delphi recommendations, World Neurosurgery X 2024; operative indications, timing, technique and fusion sections read 13 September 2026. Surgery is individualised for CES, progressive neurological impairment or severe motor deficit; evidence is insufficient to prefer one minimally invasive method, and fusion is not routine for isolated first-time disc radiculopathy. Chapter-specific use: acute disc prolapse with neurological deficit.
NICE NG59 low back pain and sciaticaNICE NG59, published 30 November 2016 and updated 11 December 2020; imaging, sciatica and decompression recommendations read 13 September 2026. It applies to people aged 16 and over with routine low back pain/sciatica and explicitly excludes progressive neurological deficit or cauda equina syndrome. Chapter-specific use: acute disc prolapse with neurological deficit.