Cauda Equina Syndrome: Junior Doctor Guide & Clerking Template

Q: What are the red flags for suspected cauda equina syndrome?

Bilateral sciatica — think CES; Saddle / perianal numbness — think CES; New difficulty passing urine, or reduced sensation of passing it — think CES; Painless retention or overflow incontinence — think CES with retention (CES-R); Faecal incontinence / loss of rectal sensation — think CES; New sexual dysfunction — think CES; Known cancer, fever, IVDU — think MSCC / epidural abscess

Q: What is the initial management of suspected cauda equina syndrome?

Targeted history (bladder, bowel, saddle sensation, sexual function, bilateral leg symptoms); Full lower limb neuro (power, reflexes, sensation by dermatome); Saddle / perianal sensation (pinprick, documented clearly; anal tone per local pathway); Bladder scan after voiding (post-void residual volume); Emergency MRI lumbar spine (per local pathway, 24/7); Spinal on-call (if MRI confirms compression)

Q: What diagnoses must you not miss in suspected cauda equina syndrome?

Cauda equina syndrome (bladder · bowel · saddle); Metastatic spinal cord compression (known cancer); Spinal epidural abscess (fever · IVDU)

Q: What investigations should a junior doctor order for suspected cauda equina syndrome?

MRI: Emergency, per local pathway, whenever CES is suspected — don't wait for retention.; Bladder scan: Large residual with symptoms supports CES; a normal one doesn't exclude it.; Bloods: FBC, CRP, cultures, calcium, myeloma screen.

Q: Admit or discharge: how is the plan decided for suspected cauda equina syndrome?

Home: MRI excludes compression; analgesia, physiotherapy, CES warning card and clear safety-netting.; Spinal surgery: MRI confirms CES — urgent decompression.

Settle them, and check the basics

ask · examine · scan

Red flags — what each should make you think

Bilateral sciaticaCES Saddle / perianal numbnessCES New difficulty passing urine, or reduced sensation of passing itCES Painless retention or overflow incontinenceCES with retention (CES-R) Faecal incontinence / loss of rectal sensationCES New sexual dysfunctionCES Known cancer, fever, IVDUMSCC / epidural abscess

🩺

Pearl

The goal is to catch cauda equina before retention. CES-I (incomplete: sensory change, altered urinary sensation, but still controlling the bladder) has much better outcomes than CES-R (painless retention, overflow). Waiting for retention means you've waited too long.

First actions

📝Targeted history
🦵Full lower limb neuro
SSaddle / perianal sensation
PVRBladder scan after voiding
MRIEmergency MRI lumbar spine
☎Spinal on-call

Understand the patient

CES-I vs CES-R

Stages

CES-Suspected — bilateral radicular symptoms without bladder/bowel/saddle changes
CES-Incomplete (CES-I) — altered urinary sensation, loss of desire to void, poor stream, needing to strain; saddle sensory change
CES-Retention (CES-R) — painless urinary retention and overflow incontinence
CES-Complete — no saddle sensation, retention, loss of anal tone

Use a CES warning card on discharge for patients with back pain and sciatica, so they know which symptoms to return for.

Causes

Central lumbar disc prolapse (most common, usually L4/5 or L5/S1)
Spinal stenosis, spondylolisthesis
Tumour (metastases), infection (epidural abscess, discitis), haematoma (post-op, anticoagulants), trauma

Work A–E — assess and act as you go

AAirway. ——

BBreathing. ——

CCirculation. ——

DDisability. Lower limb neuro, saddle sensation, reflexes (ankle reflexes lost).document clearly

EExposure. Spine tenderness, bladder (palpable), temperature (infection), signs of malignancy.bladder scan

The diagnoses you must not miss

tap to open each

What points toward it, what would rule it in, and how to manage it.

points toward it

Back pain with bilateral sciatica, saddle numbness, urinary changes, bowel or sexual dysfunction.

rule in

Emergency MRI lumbar spine.

manage it

Emergency decompression by the spinal surgeons.

Source: GIRFT — national suspected CES pathway

points toward it

Known cancer, thoracic or band-like pain, progressive neurology, night pain.

rule in

MRI whole spine.

manage it

Dexamethasone, oncology/spinal team. See the spinal cord compression page.

Source: Spinal cord compression page

points toward it

Back pain, fever, IVDU, diabetes, immunosuppression, recent spinal procedure; progressive neurology.

rule in

MRI with contrast, blood cultures, CRP.

manage it

Antibiotics, spinal surgery for drainage/decompression.

Source: spinal team

Investigate — what to order, when, and what it tells you

test with a question in mind

MRI

When

Emergency, per local pathway, whenever CES is suspected — don't wait for retention.

Bladder scan

Post-void residual

Large residual with symptoms supports CES; a normal one doesn't exclude it.

Bloods

If infection/cancer suspected

FBC, CRP, cultures, calcium, myeloma screen.

How the plan comes together

disposition · handover

home

MRI excludes compression; analgesia, physiotherapy, CES warning card and clear safety-netting.

spinal surgery

MRI confirms CES — urgent decompression.

Hand over: time of symptom onset, CES stage, neuro exam, PVR, MRI findings.

🩺

Pearl

Ask the four questions (bladder, bowel, saddle, sex) of every back pain patient, examine saddle sensation, scan the bladder, and get the MRI. Then document it all clearly. Nicely done getting here.

✎

Clerking template

copy or download

Cauda equina syndrome — documentation structure

A structure and prompt list to help you document and think systematically. It is not a completeness check and cannot guarantee nothing is missed — use your trust's own proforma, your seniors, and your clinical judgement.

CAUDA EQUINA SYNDROME — CLERKING TEMPLATE PRESENTING COMPLAINT: HISTORY OF PRESENTING COMPLAINT Back pain — onset / trauma / previous: Leg symptoms — unilateral / bilateral / dermatome: Bladder — hesitancy / straining / poor stream / altered sensation / retention / incontinence: Bowel — incontinence / altered sensation: Saddle numbness: Sexual function change: Cancer / fever / IVDU / anticoagulants: RED FLAGS ASKED (record present or absent) [ ] Bilateral sciatica -> CES [ ] Saddle / perianal numbness -> CES [ ] New difficulty passing urine, or reduced sensation of passing it -> CES [ ] Painless retention or overflow incontinence -> CES with retention (CES-R) [ ] Faecal incontinence / loss of rectal sensation -> CES [ ] New sexual dysfunction -> CES [ ] Known cancer, fever, IVDU -> MSCC / epidural abscess SCORES / KEY CHECKS Lower limb power (L2-S1): Reflexes (knee / ankle): Sensation (dermatomes): Saddle / perianal sensation (pinprick): Anal tone (if examined): Post-void residual (mL): CES stage: suspected / incomplete / retention MRI requested (time): PAST MEDICAL HISTORY: DRUG HISTORY: ALLERGIES: SOCIAL HISTORY (smoking / alcohol / function / who's at home): FAMILY HISTORY: OBSERVATIONS: RR SpO2 ( % O2) HR BP Temp GCS NEWS2 EXAMINATION A - B - C - D - (GCS pupils glucose ) E - INVESTIGATIONS ORDERED: IMPRESSION: DIFFERENTIALS CONSIDERED: [ ] Cauda equina syndrome [ ] Metastatic spinal cord compression [ ] Spinal epidural abscess [ ] Unilateral radiculopathy [ ] Spinal stenosis [ ] Urinary retention (other cause) PLAN: 1. 2. 3. ESCALATION / SENIOR DISCUSSION: Discussed with: Time: Advice: SAFETY NET / IF DETERIORATES: Documented by: Grade: Date/Time:

Test yourself

active recall

Cover the answer, say it out loud, then reveal. Retrieval beats re-reading.

0 / 10 known

Red flag

Bilateral sciatica — what should it make you think?

CES

Red flag

Saddle / perianal numbness — what should it make you think?

CES

Red flag

New difficulty passing urine, or reduced sensation of passing it — what should it make you think?

CES

Red flag

Painless retention or overflow incontinence — what should it make you think?

CES with retention (CES-R)

Red flag

Faecal incontinence / loss of rectal sensation — what should it make you think?

CES

Red flag

New sexual dysfunction — what should it make you think?

CES

Red flag

Known cancer, fever, IVDU — what should it make you think?

MSCC / epidural abscess

Must not miss

How do you rule in cauda equina syndrome?

Emergency MRI lumbar spine.

Must not miss

How do you rule in metastatic spinal cord compression?

MRI whole spine.

Must not miss

How do you rule in spinal epidural abscess?

MRI with contrast, blood cultures, CRP.

Frequently asked questions

quick answers

What are the red flags for suspected cauda equina syndrome?

Bilateral sciatica — think CES
Saddle / perianal numbness — think CES
New difficulty passing urine, or reduced sensation of passing it — think CES
Painless retention or overflow incontinence — think CES with retention (CES-R)
Faecal incontinence / loss of rectal sensation — think CES
New sexual dysfunction — think CES
Known cancer, fever, IVDU — think MSCC / epidural abscess

What is the initial management of suspected cauda equina syndrome?

Targeted history — bladder, bowel, saddle sensation, sexual function, bilateral leg symptoms
Full lower limb neuro — power, reflexes, sensation by dermatome
Saddle / perianal sensation — pinprick, documented clearly; anal tone per local pathway
Bladder scan after voiding — post-void residual volume
Emergency MRI lumbar spine — per local pathway, 24/7
Spinal on-call — if MRI confirms compression

Always alongside senior support and your local guideline.

What diagnoses must you not miss in suspected cauda equina syndrome?

Cauda equina syndrome — bladder · bowel · saddle
Metastatic spinal cord compression — known cancer
Spinal epidural abscess — fever · IVDU

Open each one in the must-not-miss section for what points toward it, how to rule it in, and how to manage it.

What investigations should a junior doctor order for suspected cauda equina syndrome?

MRI — Emergency, per local pathway, whenever CES is suspected — don't wait for retention.
Bladder scan — Large residual with symptoms supports CES; a normal one doesn't exclude it.
Bloods — FBC, CRP, cultures, calcium, myeloma screen.

Admit or discharge: how is the plan decided for suspected cauda equina syndrome?

Home — MRI excludes compression; analgesia, physiotherapy, CES warning card and clear safety-netting.
Spinal surgery — MRI confirms CES — urgent decompression.

Is there a clerking template for suspected cauda equina syndrome?

Yes — there is a free clerking template for suspected cauda equina syndrome on this page, structured as presenting complaint, red flags asked, history, examination (A–E), investigations, differentials, plan and escalation. You can copy it or download it as a Word document. Jump to the template.

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