Cauda Equina – Red flags updated

Written by senior solicitor Christian Beadell and solicitor Nafisa Ismail. 

The Medical Protection Society (MPS) and National Institute for Clinical Excellence (NICE) have recently combined to prepare and update to the clinical knowledge summary (CKS) for recognising cauda equina syndrome.

The CKS serves to provide medical practitioners with a summary current evidence and core guidance for managing a wide range of conditions. The most recent updated has been prepared following concerns raised by a  leading spinal surgeon, Mr Nick Todd, in early 2017 that the guidance at that time was not effective in preventing significant neurological harms as many of the red flags which were being used to trigger further referral/investigation were themselves indicators that significant harm had already occurred. The recommendation was that the threshold for referral should be lowered so that there was better prospect of intervening before neurological damage occurred or became permanent.

1. The updated guidance has been published by MPS and NICE and can be found here. For details of the MPS announcement please click here.

The red flags are shown below with the additional content highlighted in red:

1. Bilateral sciatica
2. Severe or progressive bilateral neurological deficit of the legs, such as major motor weakness with knee extension, ankle eversion, or foot dorsiflexion
3. Difficulty initiating micturition or impaired sensation of urinary flow, if untreated this may lead to irreversible urinary retention with overflow urinary incontinence (The old flag requiring the actual onsent of urinary retention has been changed)
4. Loss of sensation of rectal fullness, if untreated this may lead to irreversible faecal incontinence (this replaces the old flag which required the actual onset of faecal incontinence)
5. Perianal, perineal or genital sensory loss(saddle anaesthesia or paraesthesia)
6. Laxity of the anal sphincter

The new guidance is aimed at identifying potentially damaging deterioration before significant complications arise. The MPS view is that  “Any patient who complains of perineal sensory impairment (whether uni or bilateral) or change of bladder or bowel function should be sent urgently to hospital”.

In reality the presence of any form of bladder or bowel disturbance combined with a lower back pain should have raised concerns even before the updated guidance, but practices would vary between different regions.  This clarification should serve to provide greater certainty and consistency and we would hope to see more prompt , early referrals when symptoms present.

In addition, we would expect to see advice given to patients to improve so that they themselves have a better understanding of when their condition has progressed and they should seek out treatment. We have seen a number of cases where a patient with long term chronic back pain goes on to develop cauda equina syndrome without recognising the significance of symptoms because they have not been alerted to warning signs by their treating doctor.