CES has stages, kind of
Thanks for reading the 50th (🎉) edition of my newsletter. This newsletter tracks my research as I write a book about sciatica, and another one (out very soon) about cauda equina syndrome.
Hi from a fancy cafe this week,
We are nearly ready to go with the CES book. We're waiting for some notes from a few expert readers and, definitely my least favourite part of this process, going through the text for any last minute typos or formatting issues. We might have to push back the launch date a bit but it's all looking good. I feel like I might be able to relax soon, but I don't think I will be able to do so properly until the paperback copies of the book start to arrive through letterboxes safe and sound.
After talking about communication last week, this week I want to talk again about this idea that CES unfolds over time. In fact, there are names for the 'stages' it goes through.
Going back a bit
Surprisingly recently, CES itself didn't even have a name. There are case studies from back in 1910 where the patient clearly had CES, but the physician didn't have a name for it and in fact didn't even know what had caused it. In one, a physician describes manipulating his patient's spine, only to watch in horror as his patient gradually lost all feeling in his legs and all control of the sphincters of his bladder and bowel. He had no idea what was going on. (For more on this history, see my article here)
Although Mixter and Barr discovered that disc prolapses can injure the cauda equina in the 1930s, the earliest papers (that I could find) that mention the term ‘cauda equina syndrome’ aren’t until the 1940s. And even by 1960, James Cyriax could still write about CES as "a little known fact", expressing his dismay that so many of his colleagues weren't alert to this niche condition. Hard to imagine now.
Over the next few decades, CES did get a higher profile. But as far as I can tell, people didn't really start to talk about 'stages' of CES until the 2000s.
Incomplete and Retention
The first key paper was by Gleave and MacFarlane, who wrote in 2002 that there is a distinction between incomplete CES and CES with retention.
‘A patient with urinary difficulties of neurogenic origin, including altered urinary sensation, loss of desire to void, poor urinary stream and the need to strain in order to micturate’ has incomplete cauda equina syndrome, or CES Incomplete. Physiologically, at the CES Incomplete stage, the nerves of the cauda equina are still conducting impulses to and from the bladder, just fewer of them; i.e. an incomplete conduction block.
On the other hand, a patient with ‘painless urinary retention and overflow incontinence, where the bladder is no longer under executive control’ has cauda equina syndrome with retention. CES with Retention comes after CES Incomplete, and it can cause profound disability. Physiologically, at the CES Retention stage, the nerves of the cauda equina are conducting much fewer impulses to and from the bladder, or perhaps none at all; at any rate, not enough for bladder function. (For more detail on what's going on with the bladder, how retention works etc., see my previous newsletter here).
Enter, CES Suspected
So we have CES Incomplete and CES Retention.Â
Now, enter CES Suspected. This isn't really CES; it's ‘pre-CES’. It was first proposed in the 2009 guidelines of the Society of British Neurosurgeons and then refined in 2017 by Todd. CES Suspected is bilateral radicular pain and/or radiculopathy. The idea is that such a presentation implies a large central herniation (or other mass) is contacting the nerve roots on both sides. And a large central herniation is what tends to cause CES. So we should suspect that the patient with bilateral radicular pain and/or radiculopathy is on the brink of developing CES proper.Â
CES Suspected is what kicked off 'bilateral sciatica-gate' a few years ago, when suddenly everyone wondered if they had to send everyone with who fit the profile to A&E…
One last category: CES Complete.
According to Lavy and colleagues, there isn't really an origin for the phrase ‘CES Complete’, it's just something that's emerged amongst clinicians.Â
If CES Retention is a loss of motor and sensory function in the bladder, then CES Complete is a loss of motor and sensory function in everything else: the anal sphincter and bowel, the saddle area and the sexual organs. The category of CES Complete is a reminder that although CES Retention is bad, it's not quite the end of the line and things can still get worse.
So now we have CES Suspected, Incomplete, Retention and Complete. It's important to note that these stages don’t happen to any particular time scale. Someone could get CES Complete in seconds (likely through a trauma), or have CES Incomplete for days or weeks before it progresses to CES Retention. (Not to mention people with what Comer and colleagues call ‘grumbling CES’, who have an incomplete conduction block for years).
Anyway, all in all, we can represent these categories like so:
Or, like Lavy and colleagues did in this paper:
Who cares?
I do!
These stages are not perfect. There are some ways they don’t map perfectly onto clinical reality. For example, there's not necessarily a 'CES Suspected' leg pain phase before actual CES signs and symptoms kick in. And it's not necessarily the case that bladder symptoms are at the forefront; in fact, sometimes people do have CES with no bladder symptoms at all.Â
Nevertheless, I think they offer us a useful perspective, and give us some useful words to help make sense of the messiness of clinical practice.
More than anything, these stages anchor and give detail to the crucial lesson that CES unfolds over time. In other words, CES is more than a checklist of symptoms, or a collection or red flags. It's a story, and when you're with a patient you're just seeing one moment, one snapshot of that story. What’s happened so far? And what might happen next?
On top of that, the stages CES Suspected and CES Incomplete also alert us to the idea that it’s important to ‘catch’ CES before the Retention stage or, God forbid, the Complete stage. You can’t mess around if you suspect something.Â
Final reflections…
The problem is that all this does make our job more difficult! If we are supposed to pick up on some of the more subtle symptoms of CES Incomplete, then we have to tease out those subtle symptoms from all the other, much more common non-emergency causes of a bit of faecal incontinence or a bit of urinary hesitation or a bit of erectile dysfunction. And we also have to consider the costs and harms of referring more patients for emergency assessments...
It seems to me we are in ‘a moment’ right now in the MSK professions where we’re trying to get all this right. I’m excited to see what will happen in the near future. The great and the good among us are working to improve pathways, write new guidance and spread the message widely. (And maybe our book will have a small role to play, by helping clinicians with the nitty-gritty of CES conversations and CES decisions 😊).
Anyway, I finished this flat white ages ago and the mustachioed barista is giving me ‘hurry up’ looks. This didn’t happen last week in McDonalds…
Til next time,
Tom
P.S. As always, do reply to let me know your thoughts and disagreements, or just to say hello!