Thursday, 30 October 2014

Pain and adolescent Chronic Fatigue Syndrome

"We found a higher prevalence of severe pain among adolescents with CFS [Chronic Fatigue Syndrome] and lowered pain thresholds compared with HCs [healthy controls]".

That was the headline generated by the study from Anette Winger and colleagues [1] (open-access) looking to describe several parameters tied into experience of pain in the context of CFS. Further: "The total sum of bodily symptoms represented a heavy burden with great functional consequences".

Your hokey pokey dragon is out helpin' Santa Claus pull his sled!
The Winger paper is open-access, and pretty self-explanatory in terms of the hows and whys of the study (including strengths and limitations) so no need for me to further complicate things. As part of the NorCAPITAL project (The Norwegian Study of Chronic Fatigue Syndrome in Adolescents: Pathophysiology and Intervention Trial) (ClinicalTrial.gov entry here) which has already reported on the use of clonidine for CFS [2], the latest publication is an important add-on.

There are a few details included in the results which do however merit some additional highlighting. So:

  • "In the present study, almost three-quarters of the adolescents with CFS suffered from weekly pain, and pain on a daily basis was a problem for half of the patients". This was "highly significant" when compared with reports from controls, particularly where two-thirds of CFS participants reported weekly headaches. 
  • Muscle and joint pain were also recorded by adolescents with CFS alongside almost half reporting abdominal pain. Indeed, joint pain showed the most disparity between the groups with reports of such pain tipping 70% in the CFS group compared with only 10% of controls reporting this more frequently than once a month.
  • When looking at result examining the pressure pain threshold (PPT) - "the minimum intensity of a stimulus that is perceived as painful" - and examining scores based on completion of the Brief Pain Inventory (BPI), authors concluded that: "At all measure points, PPTs were significantly lower (all p<0.001) among patients with CFS than HCs".
  • "In our study, the adolescents reported that pain interfered with school, general activity and mood; however, we cannot conclude from this study that pain has a causal effect, because it could be the other way around". 

What's more to say about this research? Well, the very important message that the presentation of CFS might go well beyond just 'chronic fatigue' is paramount. This is not new news to science and practice as per the various reviews on the topic of pain exemplified by Nijs and colleagues [3]. I dare say that some public perceptions of CFS/ME would also change if more people understood that pain is a seemingly important manifestation of the condition. Oh and that CFS and pain sensation might not just be all in the mind...

I'm also inclined to introduce the condition fibromyalgia (FM) into proceedings, given the many and varied reports talking about key symptoms overlapping [4]. I'm not altogether sure of the hows and whys of FM and CFS connecting, but certainly the primary FM symptom of widespread pain and extreme sensitivity strikes me as being potentially important. With no medical advice given or intended and perhaps somewhat counter-intuitive to analgesia, the increasing body of work looking at the use of something like low-dose naltrexone (see here for some of my interest in this area) for pain in FM [5] may also very well be something in need of a little more study with pain in CFS in mind, alongside other possible pain relief options.

So then, The White Stripes with Ball and Biscuit.

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[1] Winger A. et al. Pain and pressure pain thresholds in adolescents with chronic fatigue syndrome and healthy controls: a cross-sectional study. BMJ Open. 2014; 4(10): e005920.

[2] Fagermoen E. et al. Clonidine in the treatment of adolescent chronic fatigue syndrome: a pilot study for the NorCAPITAL trial. BMC Research Notes 2012, 5:418

[3] Nijs J. et al. Pain in patients with chronic fatigue syndrome: time for specific pain treatment? Pain Physician. 2012 Sep-Oct;15(5):E677-86.

[4] Aaron LA. et al. Overlapping Conditions Among Patients With Chronic Fatigue Syndrome, Fibromyalgia, and Temporomandibular Disorder. Arch Intern Med. 2000;160(2):221-227.

[5] Younger J. et al. Low-dose naltrexone for the treatment of fibromyalgia: findings of a small, randomized, double-blind, placebo-controlled, counterbalanced, crossover trial assessing daily pain levels. Arthritis Rheum. 2013 Feb;65(2):529-38.

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ResearchBlogging.org Winger, A., Kvarstein, G., Wyller, V., Sulheim, D., Fagermoen, E., Smastuen, M., & Helseth, S. (2014). Pain and pressure pain thresholds in adolescents with chronic fatigue syndrome and healthy controls: a cross-sectional study BMJ Open, 4 (10) DOI: 10.1136/bmjopen-2014-005920