Cauda Equina Syndrome (CES) is a potentially devastating condition, with the potential for rapid deterioration. It is usually caused by the herniation of a spinal disc which then presses on the bundle of nerves at the base of the spinal cord, including those controlling bladder and sphincter function, sexual sensation and lower limb power. Broadly speaking, research indicates significantly worse outcomes in patients who do not undergo surgery within 24 hours of the onset of symptoms, and therefore prompt diagnosis is essential.
CES represents only around 0.12% of patients presenting to hospitals and GPs with back pain and is therefore a very rare condition. Many patients who suffer with back pain do not have CES, although some of the signs of the condition can be similar to, or only subtly different to other causes of back pain. This may explain why despite the serious consequences, Penningtons Manches’ clinical negligence team continues to see a number of cases with delays in diagnosis of CES.
Doctors cannot be expected to have in depth knowledge of all of the diseases they may be faced with, but they should be aware of those key symptoms that suggest a serious underlying cause, or warrant further investigation, and be able to elicit relevant information from patients. While in some cases the patient’s presentation can be subtle or atypical, there are signs which must be identified, documented, and acted upon.
The National Institute for Health and Care Excellence (NICE) has updated its guidance on these ‘red flag’ symptoms to include:
Taking a thorough history means listening carefully to the patient’s account and then following this up with systematic questions to expand on their concerns, but also to explore other problems which may not be at the top of their list of concerns.
Back pain in itself is a very common problem, and limited NHS resources in particular mean that not every case can be investigated urgently. Serious and permanent damage can be caused within hours for patients with CES, so it is essential to differentiate those patients with potential CES from those without, and asking detailed questions about sensation and bladder/bowel function in particular can mean the difference between missing a potential case or picking it up. These findings then need to be clearly documented in the medical notes.
The difficulty that some patients face is that they tend to present to hospital, or their GP, mainly concerned about their back pain, which is often severe and unrelenting, and any other signs may be secondary in their minds. Patients may not be aware of the significance of signs relating to urinary and bowel habits, or sexual sensation, and furthermore, these are potentially sensitive subjects.
Therefore, either through lack of knowledge or because of embarrassment, patients may not initially volunteer this information. This is where a full clinical history with a sensitive approach is essential, and doctors need to be aware that patients may have very different ways of describing these symptoms, which are unlikely to use medical terminology. Patients are far more likely to talk about ‘numbness’ or ‘pins and needles’ than ‘paraesthesia’ and ‘weakness’ or ‘collapse’ rather than ‘neurological deficits’. Difficulty with micturition may only be noted as a stuttering flow of urine or even simply a different sound in the toilet bowl.
As well as the existence or absence of these symptoms, it is also critical to record the duration of the symptoms and whether they are progressive. As above, whether a symptom is progressing or not can be the difference between it being considered a ‘red flag’ or not. CES in general is a progressive condition, and knowing how long elements of the condition have been present may help clinicians to decide how urgently surgery should be performed. There is some debate between clinicians about how critical the timing of surgery is, but it is generally agreed that urgent surgery is required in most cases.
Sadly for some patients, if a history is not thorough, these important signs and symptoms can be missed. If the right questions are not asked, this can have a knock on effect. Other clinicians will read these notes and may depend on them when considering further investigations. Trusts are alert to the importance of accurate history taking and also aware that in the absence of a recorded account of a history, doctors may be criticised. This is accurately reflected in some trusts’ paperwork: “If it’s not documented, it didn’t happen.”
Following a detailed history, if CES is a potential diagnosis, a full examination should be undertaken to either confirm or rule it out. Sensory abnormalities can sometimes be subjective and while examination for anal or genital sensation is clearly an invasive test, it is usually mandated if the history suggests any potential diagnosis of CES. Altered sensation in the saddle area, or reduced anal tone would normally be key prompts for further investigation, and in conjunction with the clinical signs, an urgent MRI scan would be required.
Penningtons Manches’ specialist Cauda Equina team has significant experience in conducting CES claims. Philippa Luscombe, a partner in the team, commented: “More often than not with these claims the problem is one of diagnosis. A thorough history is really the cornerstone of an accurate investigation and we have seen several cases where the absence of one small but vital piece of information has meant the diagnosis is missed. A thorough history should lead to a targeted and appropriate examination, which will then identify whether further testing is required. It is therefore essential that clinicians carry out this initial discussion in a full and detailed fashion, and it is recorded accurately even if it is a laborious process.”