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Cauda Equina Syndrome - DRAFT

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Cauda equina syndrome (CES) is a serious spinal condition that requires immediate assessment, investigation, and treatment. If it is unrecognised or treatment is delayed, this may result in permanent loss of bladder and bowel function, loss of sexual function, and lower limb paralysis. Patients may continue to experience ongoing severe disability despite prompt treatment but, if it is treated before symptoms become severe, this can reduce the risk of permanent disability.

CES is due to acute or rapidly progressive compression of the nerves in the lumbar or sacral spinal canal. The most common cause is a large lumbar disc prolapse but can be due to rarer causes such as trauma, infection, tumour, or spinal/epidural anaesthetic

Patients with CES can present to clinicians throughout primary and secondary care and it is essential that there is rapid access to imaging to confirm the diagnosis. The gold standard investigation is MRI scanning.

CES can be divided into three types, depending on the presenting symptoms:

  • CES-Suspected - Presents with bilateral radiculopathy. There is a risk of progression to CES-I or CES-R. Good prognosis with treatment
  • CES-Incomplete - Presents with impaired perineal sensation and some sphincter disturbance. Some voluntary control is maintained. Risk of progression to CES-R.
    Reasonable prognosis with early treatment.
  • CES-Retention - Presents with painless urinary retention and loss of sphincter function. May lead to serious disability. Poor prognosis even with early treatment.

The presenting symptoms can be wide ranging and variable in their apparent severity. CES is a clinical constellation and not all symptoms are relevant to diagnosing CES. Some of the symptoms may be due to other causes and clinicians will need to assess each case individually.

No single symptom or sign is pathognomonic and clinicians need to have a high suspicion for CES and a low threshold for investigating it further. Over 80% of patients with these symptoms do not have CES on an MRI scan. This means an MRI is the only way to confirm if CES is present.

Potential CES symptoms may include:
1. Bladder + Bowel dysfunction:
- Painless urinary retention
- Perineal, perianal or genital sensory loss
- Difficulty initiating micturition or impaired sensation of urinary flow
- Loss of rectal filling sensation
- Laxity of the anal sphincter
- Faecal incontinence or urinary overflow incontinence
2. Limb symptoms
- Progressive or severe lower limb neurological deficit
- Bilateral sciatica (and/or back pain) [see below]
3. Sexual dysfunction
- Altered sexual function / Erectile dysfunction / Internal sensation changes


Who to Refer

All patients with suspected CES need MRI scan with the urgency depending on type and duration of symptoms.

Emergency - progressive neurological CES symptoms (any duration) or acute onset (<72hrs). ?Send to ED

Next morning - non-progressive CES symptoms with duration of 72hrs-2wks. ?Sent to ED

Urgent (<72hrs)  - non-progressive CES symptoms with duration 2-4wks. ?Refer on ICE to local radiology department

Soon (<2 wks) - non-progressive CES symptoms with duration >4wks. ?Refer on ICE to local radiology department 


Red Flags

The following should be seen in hospital as an emergency (?ED , ?999):

  • Patients with painless urinary retention and loss of sphincter function
  • Patients with progressive symptoms of CES of any duration
  • Patients with acute onset of symptoms (within the last 72 hours).

In addition, a next day MRI scan should be arranged for (?ED)

  • Patients with non-progressive CES symptoms with duration 72 hours - 2 weeks


What to do before referral

When a patient contacts primary care with symptoms of CES, they should be assessed by a clinician as an emergency. Delaying review until an available clinic slot or sitting in the waiting room for prolonged periods is not acceptable.

History - Assessment will involve a history of current symptoms, duration of symptoms, and any recent progression.

If a patient is assessed in a primary care virtual consultation and deemed to have features of CES, they do not need to be seen in a face to face clinic if this will add a delay to subsequent imaging.

Examination - If a patient is seen in a F2F appointment, a neurological examination should be performed to identify any lower limb neurological deficit or perineal sensory deficit. Current NICE guidance states that a digital rectal examination does not need to be performed in primary care since clinicians may not be qualified to do that or not have suitable facilities and chaperone support. However, if a chaperone is available for a qualified clinician, assessing perineal sensory changes will allow monitoring of any clinical progression.

Documentation - Clear documentation on timings, severity and quality of symptoms and signs is essential to allow comparison at a later date, and also to plan timing of MRI scan.





? Refer all patients to local ED using pro-forma (Somerset model)

? Refer emergency cases to ED and all other cases for MRI via ICE (with safety netting). If positive then patient referred to ED for assessment and onward referral to neurosurgeons.

? CES coordinator role.


Efforts are made to ensure the accuracy and agreement of these guidelines, including any content uploaded, referred to or linked to from the system. However, BNSSG ICB cannot guarantee this. This guidance does not override the individual responsibility of healthcare professionals to make decisions appropriate to the circumstances of the individual patient, in consultation with the patient and/or guardian or carer, in accordance with the mental capacity act, and informed by the summary of product characteristics of any drugs they are considering. Practitioners are required to perform their duties in accordance with the law and their regulators and nothing in this guidance should be interpreted in a way that would be inconsistent with compliance with those duties.

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