Cauda Equina Syndrome Checklist

Systematic assessment of red flag symptoms to identify patients requiring urgent investigation for Cauda Equina Syndrome.

Important Clinical Disclaimer: Cauda Equina Syndrome Checklist is intended for use by qualified healthcare professionals only. It is for educational and informational purposes and should not replace clinical judgement. Always interpret results alongside the full clinical picture and follow your local guidelines and protocols.
NEUROSURGICAL EMERGENCY

Cauda Equina Syndrome requires urgent MRI and same-day neurosurgical/spinal surgery assessment. Delays in diagnosis and treatment significantly worsen outcomes. If CES is suspected, escalate immediately.

Presenting Complaint
Cardinal Red Flag Symptoms

These are the key symptoms that suggest cauda equina compression:

Bladder Dysfunction
Saddle Anaesthesia
Bowel Dysfunction
Sexual Dysfunction
Lower Limb Neurology
Additional Concerning Features
About Cauda Equina Syndrome
What is the Cauda Equina?

The cauda equina ("horse's tail") is the bundle of nerve roots at the terminal end of the spinal cord, typically below L1-L2 vertebral level. These nerves supply motor and sensory function to the legs, bladder, bowel, and sexual organs.

Classification of CES

CES is often classified based on bladder function:

  • CES-Incomplete (CES-I): Urinary difficulties (altered urinary sensation, loss of desire to void, poor stream, need to strain) but the patient can still void
  • CES-Retention (CES-R): Painless urinary retention with overflow incontinence - represents established, complete CES

CES-I is considered a "window of opportunity" where urgent surgery may prevent progression to CES-R. Once CES-R is established, outcomes are significantly worse.

Causes
  • Large central disc herniation (most common, ~70%)
  • Spinal tumour (primary or metastatic)
  • Epidural abscess
  • Epidural haematoma
  • Trauma/fracture
  • Severe spinal stenosis
UK Guidelines

British Association of Spine Surgeons (BASS) and Society of British Neurological Surgeons (SBNS) recommend:

  • Emergency MRI for suspected CES
  • Surgical decompression as soon as safely possible
  • Documentation of timing of symptom onset and progression
  • Post-void bladder scan to assess for retention
Frequently Asked Questions

Cauda Equina Syndrome (CES) is a rare but serious condition where the nerve roots at the base of the spinal cord (cauda equina) become compressed. It is a neurosurgical emergency requiring urgent decompression, usually within 48 hours, to prevent permanent neurological damage including paralysis and incontinence.

Key red flags include: bilateral leg pain/weakness/numbness, saddle anaesthesia (numbness around perineum/genitals/anus), bladder dysfunction (retention, incontinence, altered sensation), bowel dysfunction, and sexual dysfunction. Any combination of these with back pain requires urgent investigation.

CES is a time-critical emergency. Surgical decompression is generally recommended within 48 hours of symptom onset, though earlier is better. Delays beyond 48 hours are associated with significantly worse outcomes including permanent bladder, bowel, and sexual dysfunction.

The most common cause is a large central disc herniation (prolapse), usually at L4/L5 or L5/S1. Other causes include spinal tumours, spinal stenosis, trauma, infection (epidural abscess), haematoma, or post-surgical complications. Any space-occupying lesion compressing the cauda equina can cause CES.
References
  1. Gleave JR, Macfarlane R. Cauda equina syndrome: what is the relationship between timing of surgery and outcome? Br J Neurosurg. 2002;16(4):325-328. PMID: 12389883
  2. Todd NV. Guidelines for cauda equina syndrome. Red flags and white flags. Systematic review and implications for triage. Br J Neurosurg. 2017;31(3):336-339. PMID: 28637124
  3. BASS/SBNS. Standards of Care for Established and Suspected Cauda Equina Syndrome. British Association of Spine Surgeons. 2018. SBNS Guidelines
  4. Fraser S, Roberts L, Murphy E. Cauda equina syndrome: a literature review of its definition and clinical presentation. Arch Phys Med Rehabil. 2009;90(11):1964-1968. PMID: 19887225
  5. Germon T, Ahuja S, Casey AT, et al. British Association of Spine Surgeons standards of care for cauda equina syndrome. Spine J. 2015;15(3 Suppl):S2-S4. PMID: 25637468
Emergency Action

If CES is suspected:

  1. Emergency MRI spine (whole if unclear level)
  2. Bladder scan / catheterise if retention
  3. Urgent spinal surgery / neurosurgery referral
  4. Document symptom timing precisely

Surgery should ideally occur within 48 hours of symptom onset. Earlier decompression = better outcomes.

Key Questions to Ask
  • "Any numbness in your bottom / between your legs / around your back passage?"
  • "Any difficulty passing urine? Needing to strain? Not feeling when your bladder is full?"
  • "Any loss of control of your bladder or bowels?"
  • "Any weakness in both legs?"
  • "When exactly did these symptoms start?"
  • "Are symptoms getting worse?"
CES Classification
CES-Incomplete (CES-I)
  • Urinary difficulties present
  • Can still void
  • Window of opportunity
  • Better prognosis if treated urgently
CES-Retention (CES-R)
  • Painless urinary retention
  • Overflow incontinence
  • Established/complete CES
  • Worse prognosis
Examination Points
  • Saddle sensation: Test S2-S5 dermatomes
  • Anal tone: PR examination if appropriate
  • Bladder: Post-void residual (scan or catheter)
  • Lower limb power: Hip flexion, knee extension, ankle dorsiflexion, plantarflexion
  • Reflexes: Knee (L3/4), ankle (S1), bulbocavernosus
  • Sensation: L2-S1 dermatomes, perianal
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Disclaimer

This calculator is provided for educational and informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment.

  • Always seek the advice of a qualified healthcare provider with any questions regarding a medical condition.
  • Never disregard professional medical advice or delay seeking it because of information from this tool.
  • Clinical decision-making should always incorporate the full clinical context, patient preferences, and local protocols.
  • The creators of this tool accept no liability for decisions made based on its output.

If you are a patient: please discuss any results with your healthcare provider. This tool is designed for use by medical professionals and may not be appropriate for self-assessment.