Cauda equina syndrome (CES) is a rare and severe type of spinal stenosis where all the nerves in the lower back suddenly become severely compressed
Speaking at the CES Festival 21, Dr Nish Srikandarajah, neurosurgery registrar at the Walton Centre, Liverpool, explained more about this hard-to-diagnose condition.
How is CES diagnosed?
To confirm CES, we need both a clinical and radiological diagnosis, with the clinical signs supported by the correct imaging.
The cauda equina refers to the end of spinal cord, where roots have developed – known the horse’s tail, hence the name. These supply sensation and power to your leg muscles as well as control to your bladder, your bowel and your sexual function.
So when there’s a disc pressing on that area, which happens in most cases of CES, invariably over time you get a dysfunction of these nerves.
Therefore the clinical signs would be leg weakness and loss of sensation, which could also lead to paralysis of the legs. A patient may also experience problems with their bladder and bowel function and may also experience sexual dysfunction, loss of ejaculation or orgasm.
These are all serious signs and symptoms that would point to the need for imaging.
What are the problems with CES diagnosis?
There are two main issues. The first is in terms of picking up the clinical signs, because the first port of call for most people would be a GP or A&E, who may find it hard to differentiate CES from more common lower back and leg pain.
However, there are some red flags that would alert a medical professional, such as issues with the bowel or bladder, or feeling numb in the genitals or backside. Symptoms like that would make clinicians consider CES.
The second issue is with getting an MRI scan, which is very difficult as very few institutions offer it out-of-hours. Because MRI is only available out of hours in tertiary centres, patients find it very difficult to get a scan and so do clinicians. In cases like this, they need to be calling through to us, the neurosurgeons, to verify if it’s important enough.
It is subjective as to what degree of compression requires urgent surgery. What is your opinion?
The general thinking with surgeons is that, if significant canal compromise is seen on the imaging, this would constitute compressive CES. However, as to what degree that is in terms of a percentage is always argued about in studies, so ultimately it comes down to clinicians’ personal experience.
In fact, this is an area we need to look at – is it that you need a significant canal compromise before calling it CES? Or if there’s a smaller amount of compression, maybe a local reaction, it’s still causing compromise of the nerves – does that count? That’s why research is still needed in this area.
What do you look for in a CES referral?
If I get a call, there are some important questions I would ask: do you have lower back pain? How long have you had it? Has it got worse recently? Do you have leg pain associated with it? Is it one side or both? Where does leg pain travel to? This is to figure out which nerves might be affected.
The next question would be are there any issues with the bladder or bowel? These issues can range from patients with incomplete CES, who have bit of an issue passing urine, feel a bit of numbness down there, a change in bowel habits, to those with full blown CES. In those cases, the patient will be retaining urine, they’ll be unable to fully empty their bladder, although it won’t be painful. They’ll also have considerable numbness on their backside – we would test this by asking if they can feel a pin prick.
In fact, that’s shown to be the most likely thing to go wrong if you go on to have an MRI positive diagnosis of CES; the perianal sensation starts to go.
We would also run a bladder scan to find what the post-void bladder residual is. So, once you’ve passed urine to do a bladder scan, if you’re found holding a lot of urine, even after voiding, it suggests the bladder is not functioning as well as it should. This gives a stronger indication that something’s going wrong and need to get further imaging.
What are your recommendations for rehab?
During my PhD, I interviewed quite a few patients with CES and the impression I got from them is that after having their surgery, their care tends to be quite disjointed.
So in essence, once the surgery’s done, if you have a bladder issue, you tend to see a urologist, if you have a bowel issue, you’ll see general surgeons and if you have any sort of psychiatric issues, you’ll see a psychiatrist, but there’s nobody overseeing all of this.
What we have at the Walton Centre is a CES clinic where one person acts holistically, looking at all these features that need to be fed into your care and I think that’s what’s needed.
Because the second thing I found with patients is that they were really anxious about what they could do after the operation. Could they even go for a walk? Pick up their child? Bend over?
They’re all simple things that we take for granted, but they were worried that doing them might make the CES might come back.
Obviously, it’s different depending on each patient; you have to look at what they’ve been through and what sort of operation or imaging they had before and what their outcome was to give them that advice. That’s why we need a more tailored advice, reassurance and a more holistic service for CES patients.
What are your thoughts on the current research available for CES?
We published a study a few years back looking at all the literature that’s out there and we found that people are generally conducting low quality studies, because they’re doing it only at single institutions and they’re not looking at the outcomes that matter to patients and healthcare professionals.
I think the landscape needs to change for CES in terms of research and services. One way is to develop a solid database for this syndrome, which collects outcomes that matter to patients over a long period of time, so we can follow it up and figure out the best way to manage patients with CES.
See more on the CES Festival 21 here.
