Sciatica Story with physio and triathlete Kate Charlton; and, recurrance rate of radicular pain

The Sciatica Podcast

Hi and welcome to the seventh edition of my sciatica newsletter!

This week's conversation is with Kate Charlton, a physiotherapist and triathlete from Northumberland, England. Kate has had two nasty episodes of sciatica and in this podcast she tells me about what it was like, what did and didn't work for her, and how she graded her return to sport. Our conversation will be a good resource to give to any of your patients who have radicular pain and train and compete at a high level.

We talk about

* Graded return to activity and “poking the bear”

* Kate’s very positive experience with gabapentin and neural gliding exercises

* Having hope and breaking negative cycles

As I mentioned, Kate has had two episodes of sciatica, both pretty intense. In my experience, the recurrence of sciatica can leave some patients completely distraught. After the first episode dies down, the relief must be immense. I can only imagine how sickening it must be to feel those same symptoms again.

How likely is it that lumbar radicular pain will recur after subsiding? We don't have a huge amount of information. In 2012, Suri et al. tracked 97 patients with MRI-confirmed disc herniation who received conservative care only. 79 of those patients reported a full recovery (not bad!). But of the patients who recovered, 25% reported a recurrence of their symptoms.

A few years later, Suri et al. investigated this further with a retrospective analysis of a large, multicentre trial of conservative treatment. After one year, the risk of recurrence was 23% - strikingly close to the 25% the authors found in their previous study. But at two years, this number rose to 41%, and at three years 51%!

To me, these numbers are disappointingly high. But Suri et al. do write that they may be over-estimating slightly. For one thing, there is a "background rate" of symptom reporting even in a non-clinical population. If you ask a lot of people whether they had radiating leg pain recently, as many as 10% will say yes. And, the outcome measure the authors used is probably sensitive but not specific: that is, it gets false positives from people who had, say, hip OA. Finally, we don't know how intense these recurrences were; perhaps some were faint echoes of the first episode. So, I don't think it is pushing it to say the picture might not be as bad as '1/4 of people experience a recurrence, rising to 1/2 in three years'. Nevertheless, we should be counselling our patients that recurrence is possible. Hard as that might be when we are likely sharing their immense relief.

What causes that pain to come back? Not always another disc herniation. In a 1997 study, Vik et al. got in touch with 211 patients who had received an operation for their lumbar disc herniations some years prior, in '88 and '89. 23% of those patients had had another operation in the meantime. Here's the thing: back then, MRI was not a routine part of investigations for people with sciatica. Surgeons would do a CT scan or something called radigulography (sounds like a drunk person saying 'radiculopathy’), but these are not as accurate. So, surgeons didn't quite know what to expect when they opened a patient up. In this case, they found about half of those patients who went for reoperation for their recurring symptoms didn't have a disc herniation at all.

There are a lot of explanations for this! For example, epidural adhesions, lateral stenosis... Following on from last week's newsletter, I also wonder if neuroinflammation is part of the picture. In one study (in mice!), an injury to a nerve root caused pain that slowly subsided and resolved after about six weeks. After pain had subsided, a second, identical injury caused significantly *more* pain than the first. The authors reckon this might have been caused by the persistent glial activation and inflammatory mediators, which were still present in the spinal cord after pain had resolved... The fact that contralateral sensitivity increased too also suggests this 'priming' is centrally mediated. Maybe lingering neuroinflammatory changes leave some people pre-sensitized to future stressors... (In this week’s podcast, Kate tells a great anecdote about an unusual stressor that reliably made her nerve root pain flare up.)

Other bits and bobs…

* Entrapment neuropathies: a contemporary approach to pathophysiology, clinical assessment, and management by Annina Schmid, Joel Fundaun and Brigitte Tampin. It’s great, obviously.

* Patient-facing interview with me on The Back Pain Podcast. I think this went pretty well. I hope it’s useful to share with patients. The one caveat is I talk about disc herniations a lot, so it might not be relevant to every patient (I should do a future newsletter on the different structural causes of lumbar radicular pain…)

* Transcripts are coming of all pods… but it doesn’t half take a while

* I couldn’t think of any pictures to illustrate this newsletter so here are a couple more from our road trip instead… 🤷

Til next time!

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