Cauda Equina Syndrome is a rare condition with some studies suggesting that only 600 to 1,000 cases per 100,000 people will occur in the UK each year. If it is not diagnosed promptly, then the implications for the patient and their families can be severe and life-long.

The specialist Cauda Equina Syndrome team at Penningtons Manches Cooper has represented many clients who have sadly experienced significant ramifications from issues relating to the management of the condition. By assessing where the care fell short of what should have happened in these cases, potential issues can be highlighted to both those presenting with the condition in the future and medical professionals alike, so that they can benefit from the team’s collective experience. This article focuses on the difficulties that can arise due to the lack of ‘out of hours’ radiology services and why this can have such a significant impact on the timescales in the diagnosis and treatment of the condition.

What is Cauda Equina Syndrome?

The Cauda Equina are a collection of nerves at the end of the spinal cord. Their name derives from the Latin for ‘horse’s tail’ because these nerves resemble a horse’s tail as they extend from the spinal cord, through the lumbar spine and over the sacrum, and down the back of each leg. The Cauda Equina are responsible for sensory and motor innervation to the pelvis and lower limbs, as well as bowel and bladder function. If the Cauda Equina are damaged by inflammation or compression in the lower back, symptoms may be severe and can develop rapidly. Early diagnosis and treatment are highly important to ensure that a patient achieves a good recovery: the longer it is left untreated, the more the condition will progress and the patient will deteriorate. If there is a significant delay or it is left untreated, Cauda Equina Syndrome can result in permanent paralysis of the lower limbs, urinary and bowel incontinence and sexual dysfunction.

The National Institute for Clinical Excellence has published guidance to medical professionals on the ‘red flag’ symptoms of Cauda Equina Syndrome. Last revised in February 2022, they include:

  • bilateral sciatica (ie nerve pain affecting both legs);
  • severe or progressive bilateral neurological deficit of the legs, such as major motor weakness with knee extension, ankle eversion, or foot dorsiflexion;
  • difficulty in passing urine or impaired sensation of urinary flow;
  • loss of sensation of rectal fullness;
  • perianal, perineal, or genital sensory loss (saddle anaesthesia or paraesthesia);
  • laxity of the anal sphincter;
  • erectile dysfunction.

How is Cauda Equina Syndrome diagnosed?

The sooner Cauda Equina Syndrome is diagnosed, the better chance the patient has of making a sound recovery and experiencing as few lingering symptoms of nerve damage as possible. The methods of diagnosing Cauda Equina Syndrome will generally include:

  • taking a careful and detailed history from the patient of the nature, extent and onset of their symptoms, followed by a physical examination. If Cauda Equina Syndrome is considered as a potential cause of the symptoms, this should be documented within the notes to ensure appropriate management following the initial assessment through further examinations and tests to confirm or dismiss suspicions;
  • radiology imaging – an MRI scan is considered to be the most reliable form of radiology investigation to confirm or rule out a suspicion of Cauda Equina Syndrome. This is due to the ability to depict the soft tissues as it produces images of the spinal cord, nerve roots and surrounding areas. Other potential forms of radiology investigation include a CT scan (which is an X-ray of the spinal canal that gives good definition of the bone, although visualisation of the discs is not as clearly seen on a CT scan) and a Myleogram (which is an X-ray of the spinal canal with a contrast injection that can show displacement on the spinal cord or spinal nerves due to multiple causes).

If Cauda Equina Syndrome continues to be suspected following investigation, then urgent surgery is usually recommended to remove the material that is pressing on the nerves. Urgent surgery is needed to prevent the pressure from reaching the point at which damage is irreversible.

Availability of out of hours radiology services

Many hospitals will have standard operating times for radiology services, typically from 8 am until 5-8 pm, Monday to Friday. Consequently, there may be either limited or no access to radiology services outside of these standard operating hours and this can pose problems where a patient requires urgent radiology investigation, but they present either at night, at the weekend or on bank holidays. Generally, out of hours access to MRIs is only routinely available in major trauma centres and neurosurgical units, and so arrangements will need to be put in place to transfer the patient to a specialist centre to ensure prompt investigation is carried out. However, issues do unfortunately arise in ensuring that a patient is transferred to access out of hours investigations without delay and a key factor in the breakdown in this process is poor communication between the clinicians as to why an urgent referral is being made. Penningtons Manches Cooper’s Cauda Equina Syndrome team has seen this difficulty occur in a number of cases where the referring hospital has failed to provide a clear description of the patient’s symptoms and clinical presentation, and why Cauda Equina Syndrome is considered to be the cause. Problems can also arise on the receiving end of the referral if an adequate history of why the patient is being referred from the regional hospital for further investigation is not documented. The poor communication(s) between clinician(s) can result in a breakdown in the referral process and cause unnecessary delays in the transfer of a patient to access urgent investigations.

Naomi Holland, a senior associate at Penningtons Manches Cooper, comments: "Cauda Equina Syndrome is a progressive condition which requires treatment at the earliest opportunity to ensure a good outcome for the patient. The diagnostic process, namely the access to radiology services, inevitably plays a key role in ensuring a patient receives prompt diagnosis and treatment, but complications can and do arise when a patient presents to the hospital outside core working hours. Our experience is that where out of hours imaging is not available at a particular hospital and Cauda Equina Syndrome is considered as a potential cause of the symptoms, early, full and accurate communications between the clinicians in the referring hospital and the specialist centre(s) are imperative to ensure that there are no undue delays in the investigation and referral process.”