Cauda equina syndrome – a review

Cauda equina syndrome (CES) is relatively rare but nevertheless gives rise to a number of clinical negligence claims.

The condition occurs when a lumbar disc prolapse presses on the central nerves which control bladder, bowel and sexual function and sensation to the buttock and genital area. Initially, a person may develop impaired sensation in the perineal and saddle area as well as some bladder and bowel dysfunction (incomplete CES or CESI). This is generally before permanent neurological damage has occurred and therefore hopefully reversible. Ultimately, a person can lose all bladder and bowel control (retentive / complete CES or CESR).  This is generally irreversible as permanent damage has occurred. The time it takes to progress from CESI to CESR is extremely variable. Clearly, the key to successful treatment is identifying the condition as early as possible and undertaking surgery before any permanent damage has been done. 

There has long been considerable debate in the medical world (and by extension the medicolegal world) as to the importance of the timing of surgery. There is a broad (although not complete) consensus that, once a patient reaches CESR, the timing of surgery is unlikely to make much difference to the outcome. However, in relation to the timing of treatment with patients presenting with CESI, the position has been more hotly debated.

Some have argued that there are windows of opportunity from onset of symptoms – within 24 hours, within 48 hours, after 48 hours, and that outcomes will vary depending upon the timeframe within which the decompression surgery is performed. Others have argued that the timing is not the crucial issue but rather the extent of the symptoms immediately prior to the surgery and that this is the best predictor of outcomes after surgery.

As you can imagine, these two arguments in the medical literature have been replicated in expert evidence in cauda equina claims relating to delay in undertaking surgery, with Claimants arguing a worse outcome if surgery was not performed within crucial 24 or 48 hour timeframes.

However, in January 2023, new research was published based on the largest prospective study of patients with CES ever undertaken (Woodfield et al). This arguably eclipses all other studies due to its size (over 600 patients) and extent (assessment of presentation, investigation, management and outcomes up to one year post operatively using both clinician and participant reporting). The findings are supportive of the view that the key determinant of outcome is not timing of surgery from onset of symptoms but the status of the patient’s symptoms at the time of surgery.

A few key take-aways:

• They found no association of outcome with time from symptom onset to surgery and so the findings do not support better outcomes with surgery undertaken within 48 hours of symptom onset
• There was a high level of ongoing post-operative pain and poorer than expected quality of life even in patients operated upon very quickly (most were within 3 days of presentation and within 1 day of referral to spinal services)
• 2/3 of the cohort of patients required healthcare services other than spinal surgery in the year following surgery
• Worse ODI (Oswestry Disability Index) at one year was associated with worse pre-operative ODI but not with time to surgery
• The requirement for a catheter at discharge was associated with pre-operative catheterisation but not with time to surgery
• There is evidence of potential for recovery for patients in retention or with an insensate bladder

Of course, timing is important insofar as surgery clearly prevents further deterioration but the fixed timeframes advocated by some and argued by Claimants for years have arguably been fatally undermined.

Clyde has a large and growing healthcare team around the country working on behalf of NHS Trusts, GPs and private healthcare providers. The team has extensive experience in this area of clinical negligence.