A Disconnect with Connect Health: A Reasoned View of Bilateral Leg Pain and Cauda Equina Syndrome
Last week, Graeme Wilkes, MD at Connect Health released a “white paper” blog relating to bilateral sciatica and Cauda Equina syndrome (CES). The blog has generated significant discussion and clearly this debate and discussion is to be welcomed if we are to improve the management of this patient group. In the last week, we have all had several contacts from physiotherapists and service leads seeking guidance on how to manage patients with bilateral leg symptoms, but no other manifestations of CES.
The Cauda Equina – published with permission by Ruth Eaves
This is our response to the paper by Graeme Wilkes which we would consider a “green paper”- an item to promote further discussion on the topic, which we feel warrants a broader, more nuanced approach to managing these patients. The overriding message of his paper is that patients presenting with bilateral sciatica should be sent for an emergency MRI to rule out CES. We do not advocate that patients with bilateral leg pain with an absence of CES symptoms should be scanned as an emergency. Our reasons for this are outlined below.
Bilateral sciatica has been added to the list of possible symptoms of CES, though the message is not universal or clear, as Graeme points out. There is a lack of clarity from NICE, with the Clinical Knowledge Summary adding it to the list of CES symptoms but no mention of it in the NICE guidance for LBP and sciatica. Graeme’s own mini Twitter survey showed that there is a lack of consistency in approach to managing this patient group, and the GIRFT review did not offer clear guidance.
So what are front line clinicians supposed to think of all this, and how can we move forward in a way that will not overload the system and cause unnecessary anxiety for the patients and staff involved?
We think it might be helpful to look at the terminology and definitions involved, and then discuss the management pathway for these patients.
The term bilateral sciatica is not a helpful term and perhaps we could refine it more accurately to “radicular pain” or “radiculopathy”, where we can attach not only pain distribution, but also physical testing to the diagnosis. This would at least help to remove those patients with spinally referred leg pain where there is no neurogenic origin. Whilst the definitions of radicular pain, radiculopathy and spinally referred leg pain are also not entirely consistent, they may help to refine the patient group we should be concerned about.
Once the diagnosis of bilateral neurogenic leg pain is established, we would support a reasoned approach to onward management. Referring all of these patients to ED for same day MRI is likely to have several consequences;
There will be an inevitable burden placed on ED and MRI resources, and we would argue that this would be disproportionate and would risk overloading an already overburdened system unnecessarily.
Both the patient and the clinician involved will potentially be more anxious about the condition.
The rate of negative imaging for “suspected CES” will increase further. We know already that around 90% of people referred for imaging for possible CES have negative scans, and adding bilateral leg pain to the list of indications for emergency scan would further increase this percentage.
The effect of this may be to then dilute trust in the referring clinicians, which may have the knock-on effect of decreasing acceptance of future requests for imaging/referrals.
Graeme Wilkes rightly acknowledges the excellent work of Nick Todd in the management of CES over many years, and he clearly has been very influential in helping to manage this patient group. His perspective is very much that of a secondary care spinal surgeon as you would expect. The burden and challenge of early identification of patients with CES is predominantly in primary care, and often with the first contact clinician. Given that the patient may present with much more subtle signs and symptoms in the early stages, it is clearly important to be able to explore symptoms in detail in order to identify those patients at risk. We need to identify patients who are in the classification of “suspected” or “incomplete” CES, not those “white flag” patients that Todd talks about who have Complete CES and likely very poor outcomes from surgery.
In order to identify these patients early, we already delve deeper into questions about bladder, bowel, sexual function and saddle sensation changes, as we know there are myriad of reasons for these functions to be disrupted, most of which are not CES. We would suggest a similar approach to bilateral leg symptoms. Rather than a blanket approach of onward referral, we think that careful questioning, examination and safety netting of these patients would be a prudent way forward. The majority of patients with bilateral leg symptoms will not need emergency scanning. Below are categories of patients with bilateral leg symptoms and suggested pathways which we feel reflect the more nuanced presentation of patients and may offer a reasoned way forward to managing this group of patients.
Bilateral leg pain with normal neurology, normal neurodynamic tests and no other CES symptoms- treat as per symptoms and monitor progress. Safety net with CES card or similar.
Bilateral leg pain with normal neurology, positive neurodynamic tests and no other CES symptoms- treat as per symptoms. Safety net with CES card or similar- if already had conservative treatment then may refer for scan on a routine basis (but not looking for CES)
Bilateral leg pain with abnormal neurology and normal/positive neurodynamic tests and no CES symptoms. Management depends on the degree of neurological deficit- if gross motor weakness or deteriorating neurology, then refer for an urgent scan ( but not same day) and safety net patient re CES.
Bilateral leg pain with any other CES symptoms- refer on for emergency scan
This suggested subgrouping of bilateral leg pain patients may reflect more truly the range of people seen, and may help clinicians to make an informed and balanced decision on how to manage them. Unfortunately there is very little black and white in the management of CES patients in the early stages- we know that these are a complex group of patients who do need our urgent care when appropriate. We are all committed to that and support any moves to improve the outcomes for the small number of people whose lives are so dramatically affected by CES. We also acknowledge that as first contact clinicians we have a responsibility to manage the potential risks in a balanced and reasoned way, and we feel that the approach outlined above may help to do just that.
Chris Mercer, Laura Finucane and Sue Greenhalgh