Cauda equina syndrome

Overview 
Theory 
Diagnosis 
Management 
Follow up 
Resources 

Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups: see disclaimer

ACUTE

confirmed CES

1st line – decompression surgery

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1st line –

decompression surgery

CES is a neurosurgical emergency. Decompression surgery must be performed as soon as possible for any patient who has radiologically confirmed CES.[1][15]

The objective is to alleviate compression of the cauda equina and prevent further neurological deterioration, thereby preserving the function that is present at the time of surgery.[1] Evidence suggests there is also some scope to partially reverse the neurological deficit in some patients.[22]
Catheterise the patient (if catheter is not already in place) as soon as a decision to operate has been made.[15]

For patients who retain some executive control of bladder function (CESI), surgery should be undertaken as an emergency, day or night.[15] For patients who have painless urinary retention and overflow incontinence (CESR), for whom the prognosis is less positive, surgery should be undertaken within 24 hours of the magnetic resonance imaging (MRI) scan, with the exact timing at the discretion of the surgeon.[15]

Total laminectomy, hemilaminectomy, and laminotomy are all acceptable techniques for decompression surgery.[15] The most appropriate technique is selected based on the patient's pathology and the experience of the surgeon.[6]

Ensure that all patients undergoing surgery for CES are advised that the intention is to preserve the function present at the time of surgery. There is some scope for improvement but also a small risk of making matters worse should complications occur.[17]

Pain, loss of perineal sensation, and bladder, bowel, and sexual dysfunction may persist, although significant recovery of function is possible.[1][6][45]
Outcomes tend to be worse for patients who have CESR than for those with CESI.[15][17]

Timing of surgery

The principle that emergency surgery is indicated for all patients with CES now has widespread support.[1][15] However, the precise timing thresholds remain a source of debate.[4][22]

The British Association of Spine Surgeons (BASS)/Society of British Neurological Surgeons (SBNS) standards of care document for CES states that nothing is to be gained by delaying surgery, whereas there is potentially much to be lost.[16][17] It recommends that there are no safe time thresholds for surgery and that emergency surgical decompression must take place at the earliest opportunity for all patients with imaging-confirmed CES.[16][17]
The NHS England national pathway for CES recommends that the urgency of emergency surgery depends on the degree of neurological symptoms at presentation. For patients with incomplete symptoms of CES (CESI; e.g., retaining some executive control over bladder function) surgery should be undertaken as an emergency day or night, and any reason for delay should be documented; only life-threatening cases should take priority over emergency surgery for CESI.[15] For patients with CES with painless urinary retention and overflow incontinence (CESR), for whom the prognosis is less positive, surgery should be undertaken within 24 hours of the MRI scan, with the exact timing at the discretion of the surgeon.[15] NHS England, Getting It Right First Time: national suspected cauda equina interactive pathway Opens in new window

In practice, the decision on timing of surgery can take into account the duration and clinical course of symptoms and signs, along with the potential for increased morbidity when operating at night, particularly given the complexity of the surgery for a large central disc prolapse.[16][17]

Evidence: CES severity and timing of surgery

The level of neurological dysfunction at the time of surgery (as opposed to time since symptom onset) appears to be the most significant determinant of prognosis.

A US-based retrospective cohort study of 20,924 individuals with CES reported that patients undergoing surgical decompression on hospital day 0 or 1 had better inpatient outcomes, including lower complication and mortality rates, than patients having surgery on day 2 or later.[46] Delayed surgery was associated with statistically significant increased inpatient mortality (odds ratio [OR] 9.60, P = 0.002), total complications (OR 1.41, P = 0.018), and non-routine discharge (OR 2.37, P <0.0001).[46]

Other evidence on the benefits of earlier surgery (e.g., within 24 hours) is equivocal.[6][47][48][49] The disparities in evidence may be due to differences in degree of neurological deficit among participants.[50][51]

It is likely that the level of neurological dysfunction at the time of surgery (rather than time since symptom onset) is the most significant determinant of prognosis.[49][52]

The weight of evidence suggests that loss of function in CES is a continuous process with a poorer outcome the longer the cauda equina nerve roots are compressed.[1][17]
For a significant minority of patients with CES, an irreversible neurological deficit has already occurred by the time of presentation, but it is not easy to identify which individuals fall into this subset.[18]
Incomplete CES (CESI) has a better prognosis than CES with painless urinary retention and overflow incontinence (CESR). Nonetheless, evidence suggests that more prolonged compression in patients with CESR can result in additional neurological loss and that a significant proportion of this group (around 70%) will gain some benefit from decompression surgery.[15][17]
- A prospective cohort study that followed up 621 UK adults with CES found that postoperative functional improvement occurred in significant numbers of patients who had presented with urinary retention (with or without sensation to the catheter), suggesting a benefit of surgical decompression in reversing neurological deficits among patients with CESR.[22] Some 70% of patients who had required preoperative catheterisation for urinary retention (including 57% of those who had no sensation to the catheter) were no longer using a catheter by discharge. At 1-year follow-up, only 26% of individuals who had required preoperative catheterisation still needed to use a catheter, suggesting a significant potential for recovery of bladder function in patients who present with retention with or without an insensate bladder.[22]
- The study also found that bladder outcomes and disability at 1-year follow-up were associated with severity at presentation but not with time from symptom onset to surgery, although the authors noted that the observational nature of the study limited interpretation of the implications of this finding for recommendations on urgency of surgery.[22]
A 2016 evidence review concluded that:[1]
- Incomplete CES (CESI) is a true indicator for immediate emergency surgery day or night. This recommendation was based on the finding that the longer the duration of cauda equina compression in patients with CESI, the worse the bladder outcomes (even if surgery was performed prior to deterioration to CESR).[1] One retrospective cohort study of 139 patients with CESI found that the likelihood of a patient ending up with normal bladder function restored was twice as high for those who had surgery within 24 hours compared with those operated on between 24 and 48 hours (OR 1.9, 95% CI 0.5 to 7.5).[51]
- Any patient in the early stage of CESR (<12 hours) or who has CESR with some residual sacral nerve root function should also have emergency surgery day or night. There is a paucity of evidence on the impact of timing of surgery on outcomes for this patient group; some studies do support earlier surgery, but the evidence is conflicting.[1] One small study of 17 patients with CESR showed benefit from surgery within 12 hours.[48]
- Any patient who has either prolonged CESR with no residual nerve root function or complete loss of all cauda equina function (with absent perineal and perianal sensation, a paralysed and insensate bladder and bowel, and a patulous anus) can have surgery the following day.[1]

Surgical complications

Complication rates in decompression surgery are around six times higher for patients with CES than for those who have similar surgery for other indications.[15]

To avoid bladder distension injury, the patient should be catheterised before surgery begins.[15]
A cohort study of 621 UK patients with CES reported that complications occurred in 26% of individuals, with the most common being durotomy or cerebrospinal fluid (CSF) leak (12%) and postoperative neurological deterioration (12%).[22]

Plus – bladder management

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Plus –

bladder management

Treatment recommended for ALL patients in selected patient group

Undertake a trial without catheter (TWOC) as soon as feasible postoperatively and obtain pre- and post-void bladder scans.[15]

If the post-void residual volume (PVR) is <100 mL, the patient can be discharged without a catheter.[15]
Recatheterisation with a long-term catheter is indicated if the pre-void bladder scan is >500 mL with no sensation to void OR the patient has not voided after 6 hours OR the PVR is >100 mL.
- Do not attempt a second TWOC if the first trial has failed.[15]
- An intermittent catheter is preferred, if feasible, as it is associated with lower rates of urinary tract infection, urethral trauma, and renal complications.[53][54][55][56]
- If flip/flow catheterisation is used, it must be opened at least once every 4 hours, including overnight, aiming to maintain a bladder volume <500 mL.
Refer to the appropriate service so that the patient can be taught how to self-catheterise.[15] This may be the continence, urology, or spinal cord injury team; check local protocols.[16]

At surgical outpatient follow-up, check for any ongoing urinary symptoms and refer to the appropriate service if present.[15]

Plus – bowel management

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Plus –

bowel management

Treatment recommended for ALL patients in selected patient group

Ensure that all patients treated for CES are provided with advice on the potential for ongoing neurogenic bowel problems.[15] These can include involuntary bowel movements, constipation, and impaction.[57][58]

A bowel management plan should be instigated within 24 hours of admission.[58]
Laxatives and/or bowel evacuation may be necessary.[57][59] Patients should be taught how to undertake digital rectal stimulation (DRS) followed by digital rectal evacuation (DRE).[15]
Patients with bowel dysfunction resulting from injury to the cauda equina may have areflexic (flaccid) bowel dysfunction in the short or long term, although mixed reflex and areflexic dysfunction is also possible.[58]
Referral to a bowel programme may be needed for individualised rehabilitation and ongoing management.[15][57][58][59] This may be provided by the continence, colorectal, or spinal cord injury service; check local protocols.[16]

At surgical outpatient follow-up, check for any ongoing bowel symptoms and refer to the appropriate service if present.[15]

Plus – analgesia

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Plus –

analgesia

Treatment recommended for ALL patients in selected patient group

Patients who present with suspected CES are often in significant pain. Prompt up-titration of analgesics may be needed to relieve pain and facilitate effective clinical examination and magnetic resonance imaging (MRI) scanning.[23]

Postoperative pain management

Advise the patient that it is normal to continue to experience some degree of back and leg pain after surgery and that recovery of nerve function can continue for up to 18 months to 2 years.

If a patient experiences an unusual degree of pain during this period, it is important to exclude further disc prolapse (with an MRI if appropriate).[15]

During the first 3 months following surgery for CES, acute pain management follows the standard analgesic ladder for postoperative care.[15]

Use of simple analgesia (i.e., paracetamol and/or a non-steroidal anti-inflammatory drug [NSAID] with gastrointestinal [GI] protection) is recommended.[60] Examples of suitable NSAIDs include ibuprofen or naproxen. Long-term use of NSAIDs can be associated with GI adverse effects (bleeding, perforation, or ulceration), cardiovascular thrombotic events, and renal disease. Use the lowest effective dose for the shortest effective treatment duration.
Opioids (with adjunct treatments to prevent constipation) should only be used in the very short term postoperatively. They can be considered for individuals with a high functional pain assessment score, with appropriate monitoring and advice on de-escalation of opioid use.[60] Immediate-release formulations of opioids are preferred.[60] Be aware that opioids can exacerbate bowel and bladder dysfunction. Ensure frequent re-assessment of any patient whose level of pain does require a short-term opioid.[60]

For management of chronic pain (>3 months post-surgery for CES), do not offer opioids, gabapentinoids, anticonvulsants, oral corticosteroids, or benzodiazepines.[15]

Consider lumbar nerve root block with an injection of local anaesthetic/hydrocortisone.[15]
If the patient has persistent neuropathic pain, refer for consideration of spinal cord stimulation.[15][61]

Primary options

paracetamol: 500-1000 mg orally every 4-6 hours when required, maximum 4000 mg/day

-- AND / OR --

ibuprofen: 300-600 mg orally (immediate-release) every 6-8 hours when required, maximum 2400 mg/day

naproxen: 500 mg orally initially, followed by 250 mg every 6-8 hours when required

Secondary options

codeine phosphate: 30-60 mg orally every 6 hours when required, maximum 240 mg/day

morphine sulfate: 5-10 mg orally (immediate-release) every 4 hours initially, adjust dose according to response

tramadol: 100 mg orally (immediate-release) initially, followed by 50-100 mg every 4-6 hours when required, maximum 400 mg/day

Consider – advice and referral

Use of this content is subject to our disclaimer

Cauda equina syndrome

confirmed CES

decompression surgery

Timing of surgery

Evidence: CES severity and timing of surgery

Surgical complications

bladder management

bowel management

analgesia

Postoperative pain management

Primary options

Secondary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Secondary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

Secondary options

advice and referral

Cauda equina syndrome

Treatment algorithm

confirmed CES

decompression surgery

Timing of surgery

Evidence: CES severity and timing of surgery

Surgical complications

bladder management

bowel management

analgesia

Postoperative pain management

Primary options

Secondary options

These drug options and doses relate to a patient with no comorbidities.

Primary options

Secondary options

Drug choice, dose and interactions may be affected by the patient's comorbidities. Check your local drug formulary.

Primary options

Secondary options

advice and referral