Perineural EDN

Inspired by Dunning et al 2020.[1]

Photo by Wallace Chuck on

EDN – electrical dry needling
EA – electroacupuncture
IHS – International Headache Society
ICHD-3 – International Classification of Headache Disorders 3rd edition
LBP – low back pain

key to acronyms

I chose this paper because the title includes this rather novel sounding needling intervention – perineural electrical dry needling. Dry needling has been around for a long time and was originally used to focus on the therapeutic aspects of needling as opposed to those of an injected substance in wet needling (injection). The term EDN is much more recent,[2,3] and it is physiologically indistinguishable from EA. So, why add the perineural prefix? Perhaps it helps add legitimacy to a dry needling technique that no longer targets myofascial trigger points or other sites of somatic pathology.

This is the second paper from the same group that combines EDN with spinal manipulation. The first was also highlighted on a recent blog: Shoulder EA 2020.

cervicogenic headache

This time the condition treated is cervicogenic headache, which immediately attracted my curiosity from a diagnostic perspective. I was aware that the IHS criteria (ICHD-3) for diagnosing cervicogenic headache made it rather difficult to make the diagnosis, principally by including the following criterion:

headache is abolished following diagnostic blockade of a cervical structure or its nerve supply

To be fair this is actually an improvement on a prior version that I recall required 4 months of pain relief following the diagnostic block.

In this paper the authors used criteria from a cervicogenic headache group,[4–6] and specifically removed the requirement for a response to diagnostic blockade. I think that is entirely reasonable considering the setting of this trial in physical therapy departments as opposed to those for neurology or pain.

Next I wondered about the reason for the combination of EDN and spinal manipulation. You could argue that it is a more pragmatic reflection of clinical practice, but is it? I suspect that most often patients would go for one approach and then try the other if the first did not give adequate results. I became suspicious that EDN was being used to give a positive result to a comparison of spinal manipulation with mobilisation, which may not show any significant difference.

Well the efficacy data for spinal manipulation has been somewhat limited, but a systematic review of spinal manipulation versus sham in LBP from 2016 was tentatively positive. It included 9 sham controlled trials and data pooled from 4 of them (532 patients). The effect size was small (0.36), but that is rather similar or even better than acupuncture versus sham in LBP. From a mechanistic perspective, a recent experimental trial (n=80) of lumbar spinal manipulation for LBP did not demonstrate any change in pressure pain thresholds or temporal summation compared with that following sham manipulation.[7]

A systematic review of spinal manipulation in migraine (6 trials; 677 patients) was tentatively positive, but only two of the trials used a sham control.[8]

In cervicogenic headache a review published this year in EJP found in favour of manipulation over a mixture of other manual therapies including sham, mobilisation and massage,[9] but a further trial this year failed to demonstrate any difference between manipulation and mobilisation.[10]

…too cynical of the combination approach?

So, perhaps I have been a little too cynical of the combination approach adopted by Dunning et al,[1] since the sham controlled data for spinal manipulation is not so different to that for acupuncture, and of course the methodological challenges are similar. They randomised 142 patients into 2 groups and provided 8 sessions over 4 weeks. The comparison group received mobilisation and exercise.

The results look quite good in the EDN group, and I was particularly drawn to the downward slope of the graphs after the end of treatment over the 3 months follow-up compared with the flatter result for mobilisation and exercise.

Will epineural EDN catch on then, and how does it differ from EA? All will be revealed on Wednesday at the blog webinar.

Reference list

1         Dunning J, Butts R, Zacharko N, et al. Spinal manipulation and perineural electrical dry needling in patients with cervicogenic headache: a multi-center randomized clinical trial. Spine J Published Online First: 13 October 2020. doi:10.1016/j.spinee.2020.10.008

2         Dunning J, Butts R, Henry N, et al. Electrical dry needling as an adjunct to exercise, manual therapy and ultrasound for plantar fasciitis: A multi-center randomized clinical trial. PLoS One 2018;13:e0205405. doi:10.1371/journal.pone.0205405

3         Dunning J, Butts R, Fernández-de-las-Peñas C, et al. Spinal Manipulation and Electrical Dry Needling in Patients With Subacromial Pain Syndrome: A Multicenter Randomized Clinical Trial. J Orthop Sport Phys Ther 2020;:1–46. doi:10.2519/jospt.2021.9785

4         Sjaastad O, Fredriksen TA, Pfaffenrath V. Cervicogenic headache: diagnostic criteria. The Cervicogenic Headache International Study Group. Headache 1998;38:442–5. doi:10.1046/j.1526-4610.1998.3806442.x

5         Vincent M, Luna R. Cervicogenic Headache: A Comparison with Migraine and Tension-Type Headache. Cephalalgia 1999;19:11–6. doi:10.1177/0333102499019S2503

6         Sjaastad O, Fredriksen TA. Cervicogenic headache: criteria, classification and epidemiology. Clin Exp Rheumatol 2000;18:S3-6.

7         Aspinall SL, Jacques A, Leboeuf-Yde C, et al. No difference in pressure pain threshold and temporal summation after lumbar spinal manipulation compared to sham: A randomised controlled trial in adults with low back pain. Musculoskelet Sci Pract 2019;43:18–25. doi:10.1016/j.msksp.2019.05.011

8         Rist PM, Hernandez A, Bernstein C, et al. The Impact of Spinal Manipulation on Migraine Pain and Disability: A Systematic Review and Meta‐Analysis. Headache J Head Face Pain 2019;59:532–42. doi:10.1111/head.13501

9         Fernandez M, Moore C, Tan J, et al. Spinal manipulation for the management of cervicogenic headache: A systematic review and meta‐analysis. Eur J Pain 2020;24:1687–702. doi:10.1002/ejp.1632

10       Lerner-Lentz A, O’Halloran B, Donaldson M, et al. Pragmatic application of manipulation versus mobilization to the upper segments of the cervical spine plus exercise for treatment of cervicogenic headache: a randomized clinical trial. J Man Manip Ther 2020;:1–9. doi:10.1080/10669817.2020.1834322

Declaration of interests MC