Research

Primary pain disorders


In a move likely to create some havoc in compensation systems around the world (well, at least in my corner of the world!), the International Association for the Study of Pain has worked with the World Health Organisation to develop a way to classify and thus record persistent pain conditions in the new (draft) ICD-11. While primary headache disorder has been in the classification for some years, other forms of persistent pain have not. Recording the presence of a pain disorder is incredibly important step forward for recognising and (fingers crossed) funding research and treatment into the problem of persistent pain. As the IASP website states:

Chronic pain affects an estimated 20 percent of people worldwide and accounts for nearly one-fifth of physician visits. One way to ensure that chronic pain receives greater attention as a global health priority is to improve the International Classification of Diseases (ICD) diagnostic classification.

The classifications are reasonably straightforward, with an overall classification of “chronic pain”, and seven subcategories into which each type of pain can be placed.

Now there will be those who are uncomfortable with labelling a symptom (an experience, aporia, quale) as a separate diagnosis. I can understand this because pain is an experience – but at the same time, just as depression, which is an experience with clinical and subclinical features, so too is pain. There is short-term and useful pain, serving as an alert and warning, and typically an indication of the potential or actual threat to bodily integrity. Just as in depression which has short-term and usually useful episodes of sadness, withdrawal and tearfulness (as in grief). At the same time, there are periods when sadness becomes intractable and unhelpful – and we call this depression. Underlying both of these situations are biological processes, as well as psychological and social contributors. Until now, however, persistent pain has remained invisible.

The definition of chronic pain, at this time, is the IASP one from the 1980’s:

“Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage. Often, pain serves as a symptom warning of a medical condition or injury. In these cases, treatment of the underlying medical condition is crucial and may resolve the pain. However, pain may persist despite successful management of the condition that initially caused it, or because the underlying medical condition cannot be treated successfully.

Chronic pain is pain that persists or recurs for longer than three months. Such pain often becomes the sole or predominant clinical problem in some patients. As such it may warrant specific diagnostic evaluation, therapy and rehabilitation. Chronic pain is a frequent condition, affecting an estimated 20% of people worldwide. This code should be used if a pain condition persists or recurs for longer than 3 months.”

Chronic Primary Pain is defined as “…chronic pain in one or more anatomical regions that is characterized by significant emotional distress (anxiety, anger/frustration or depressed mood) and functional disability (interference in daily life activities and reduced participation in social roles). Chronic primary pain is multifactorial: biological psychological and social factors contribute to the pain syndrome. The diagnosis is appropriate independently of identified biological or psychological contributors unless another diagnosis would better account for the presenting symptoms. Other chronic pain diagnoses to be considered are chronic cancer pain, chronic postsurgical or posttraumatic pain, chronic neuropathic pain, chronic headache or orofacial pain, chronic visceral pain and chronic musculoskeletal pain. Patients with chronic primary pain often report increased depressed and anxious mood, as well as anger and frustration. In addition, the pain significantly interferes with daily life activities and participation in social roles. Chronic primary pain is a frequent condition, and treatment should be geared towards the reduction of pain-related distress and disability.” (definition are found here)

The definition doesn’t require identified biological or psychological contributors – so people with primary pain would be those who have fibromyalgia, persistent low back pain, perhaps even “frozen” shoulder. The main requirement is that the person is distressed by it, and that it interferes with life. Now here’s a bit of a problem for those of us who have learned to live well with our persistent pain – I experience widespread pain, but generally I’m not distressed by it, and seeing as I’ve lived with it since my early 20’s, I find it hard to work out whether I’m limited by it, or whether I’ve just adjusted my life around it, so it doesn’t really get in the way of what I want to do. Technically, using the draft definition, I might not be given the label. Does this mean I don’t have chronic primary pain?

Why did I suggest compensation systems might be interested in this new classification? Well, in New Zealand, if a person has a pre-existing condition, for example they have osteoarthritic changes in their spine even if it’s not symptomatic (ie it doesn’t hurt), and then lodges a claim for a personal injury caused by accident, they may well find their claim for cover is declined.  What will happen if someone who has fibromyalgia, has an accident (say a shoulder impingement from lifting something heavy overhead), and the problem fails to settle? I think it’s possible they’ll have their claim declined. Low back pain is probably the most common primary pain disorder. Thousands of people in New Zealand develop low back pain each year. Few will have relevant findings on imaging – and even if imaging shows something, the potential for it to be directly related to the onset of low back pain is open to debate. Especially if we consider low back pain to be a condition that doesn’t just appear once, but re-occurs thereafter (1-7). What will this mean for insurers?

I don’t know where this classification will lead insurers, but from my perspective, I can only hope that by incorporating chronic pain into the ICD-11 we will at least begin to show just how pervasive this problem is, and how many people need help because of it. And maybe, just maybe, governments like the New Zealand government, will begin to take persistent pain seriously and make it a national health priority.

  1. Dunn, K.M., Hestbaek, L., & Cassidy, J.D. (2013). Low back pain across the life course. Best Practice & Research in Clinical Rheumatology, 27(5), 591-600.
  2. Artus, M., van der Windt, D., Jordan, K.P., & Croft, P.R. (2014). The clinical course of low back pain: A meta-analysis comparing outcomes in randomised clinical trials (rcts) and observational studies. BMC Musculoskeletal Disorders, 15, 68.
  3. Vasseljen, O., Woodhouse, A., Bjorngaard, J.H., & Leivseth, L. (2013). Natural course of acute neck and low back pain in the general population: The HUNT study. Pain, 154(8), 1237-1244.
  4. Hoy, D., March, L., Brooks, P., Blyth, F., Woolf, A., Bain, C., . . . Buchbinder, R. (2014). The global burden of low back pain: Estimates from the global burden of disease 2010 study. Annals of the Rheumatic Diseases, 73(6), 968-974.
  5. Campbell, P., Foster, N.E., Thomas, E., & Dunn, K.M. (2013). Prognostic indicators of low back pain in primary care: Five-year prospective study. Journal of Pain, 14(8), 873-883.
  6. Axén, I., & Leboeuf-Yde, C. (2013). Trajectories of low back pain. Best Practice & Research Clinical Rheumatology, 27(5), 601-612. doi: http://dx.doi.org/10.1016/j.berh.2013.10.004
  7. Hoy, D. G., Smith, E., Cross, M., Sanchez-Riera, L., Buchbinder, R., Blyth, F. M., . . . March, L. M. (2014). The global burden of musculoskeletal conditions for 2010: an overview of methods. Annals of the Rheumatic Diseases, 73(6), 982-989. doi:10.1136/annrheumdis-2013-204344

Everyday hassles of fibromyalgia


This post has been on my mind for a while now. I live with fibromyalgia (FM) and want to share some of the everyday hassles I face. This isn’t a “oh woe is me” kind of post, it’s more of a “if you’re a clinician working with someone who has fibromyalgia, these are some things to ponder”.

Diagnosis

I worked in chronic pain management for almost 20 years before I recognised that the pains I’d been experiencing most of my adult life actually added up to “…a syndrome of diffuse body pain with associations of fatigue, sleep disturbance, cognitive changes, mood disturbance, and other variable somatic symptoms”(Fitzcharles, Ste-Marie, Goldenberg et al, 2012). I’d hurt my back in my early 20’s, thankfully been seen by Dr Mike Butler and given the Melzack & Wall book “The Challenge of Chronic Pain” to read, so I wasn’t afraid of my pain and just accepted it as part of life. What I hadn’t really recognised was that not only was the pain in my lower back part of the picture, so too was the pain in my neck, shoulders, arms, hips, legs, feet, and the irritable bowel, and the gastro discomfort, and the migraines and the dysmenorrhoea. Not to mention the fatigue, rotten sleep, foggy thoughts, and low mood.

Diagnosis for people living with fibromyalgia is often delayed.  People with fibromyalgia may resist going to the GP for what seem to be short-term but painful bouts in various parts of the body. There for a couple of weeks, then shifting to another part of the body. As one person said to me “You feel a fool going to see a Dr about a pain that’s not consistent to say ‘Oh Doctor and I have pain here, and here and here and last week I had one here…especially when it might be gone next week, and that other one has already gone.'”. This experience is echoed in qualitative research where, for example in a study by Undeland and Malterud (2007) people said that although having a label was reassuring (it’s not something that will kill you!), the label itself was often difficult to obtain (doctors not being keen to label something so nebulous as FM), and even with a label health professionals and the general public “pay no attention to the name, or blatantly regard them as too cheerful or healthy looking” (Undeland & Malterud, 2007).

Treatment

One of the problems with getting the diagnosis is that very few people get relief from medication. Those that do may find their pain settles almost completely, but many others have no effective analgesia despite trying numerous combinations. I’m one of them. What this means is that “self management” is the order of the day – yet in many places this is not even considered, let alone having services to help people develop such skills.

I’ve learned that my body feels best when I maintain a consistent level of activity irrespective of the day of the week. I enjoy stretching, walking, cycling and dancing, but I also love gardening, fishing, walking the dog – and I guess I can add in doing the housework and working as part of the mix. New activities are bound to give me aches and pains that last for weeks, while stopping my usual routine also brings me aches and pains that last for weeks. So boring consistency is the name of the game. And as I’ve previously blogged that means I look for a variety of different movement options in my repertoire.

Everyday hassles

The one thing that makes my life difficult is when I develop a new pain in a part of my body that doesn’t usually feel uncomfortable. Like most people living with persistent pain, I’ve developed an awareness of “my normal” (see this study by Strong & Large, 1995, for a nice description of this aspect of living with pain, one that is not often discussed). I know the usual pattern of my pains – bellyache, low back pain, neck and upper back pain, wrists and fingers, and often, knees, headaches and facial pain. These are my normal – but when should I seek help for a new pain? After all, it could be simply a manifestation of my fibromyalgia (ie there is nothing medically to be found, and no real change in management). At the same time, these are new pains – one in my shoulder that feels like an impingement (painful arc), and one that’s possibly an adductor tendon thing that’s very localised and hasn’t moved for over 7 months.

The question that keeps coming back to me is whether I’m overlooking something that can be treated, or whether it’ll just settle down like most of my pains do. Essentially I’ve just kept doing what I do and ignoring it.

The difference between my situation and those of people who are not painiacs, who don’t know that their pain is largely unrelated to the state of the tissues, is that I’m immersed in pain research all day, every day. I’m not overly bothered by these new pains. I’m continuing to exercise as normal and these pains aren’t interfering with what I need and want to do in daily life (well, perhaps a little…).

I can understand why someone might ask for help for a new pain. There are no rules saying that just because you have a persistent pain disorder you’re immune from acute musculoskeletal disorders. And sometimes by treating a new pain as an acute pain, it will vanish. Though, it must be said that outcomes for people with more than 3 or 4 persistent areas of pain with low back pain are not as good as those who only have one or two (Nordstoga, Nilsen, Vasseljen et al, 2017), nor of recovery and benefit from total hip and knee replacement (Wylde, Sayers, Odutola, Gooberman-Hill et al, 2017).

Points to ponder

So how do we as clinicians help people who must live with persistent pain?

  • Do we consider the meaning of the labels we give? And do we read around the experiences of those who have been given the diagnosis? Or do we, instead, rely on our own beliefs and biases when thinking about the way we handle diagnosis?
  • Do we give people an explanation for their pain that they can understand, or do we rely on currently favoured language and models without really considering what this means to the person? And do we ever check out how they’ve interpreted our explanations?
  • Do we ever discuss how to self-manage pain? Do we think about the practical implications of needing to learn to modify every aspect of life in the face of pain that will not just go away? When I compare the tasks of living well with persistent pain against those needed to cope with other disorders, pain can interfere with everything – do we talk about the impact on sex? on relaxation? on having a holiday?
  • Do we talk about what to do when a new pain turns up? Do we think about how someone can decide whether their pain is worth seeing someone about, or one they can handle? And do we even talk about the effect of having a persistent pain problem and then going on to have surgery? Do we teach people to recognise their “normal” pain, or are we afraid to teach people this because it might focus their attention on their pain?

I don’t have researched answers to these questions. I have my experience. And I’ve been working in this field a long time – yet somehow the voices of people living successfully with this pain are rarely heard.

 

Fitzcharles, M.-A., Ste-Marie, P. A., Goldenberg, D. L., Pereira, J. X., Abbey, S., Choinière, M., . . . Proulx, J. 2012 canadian guidelines for the diagnosis and management of fibromyalgia syndrome. http://fmguidelines.ca/

Nordstoga, A. L., Nilsen, T. I. L., Vasseljen, O., Unsgaard-Tøndel, M., & Mork, P. J. (2017). The influence of multisite pain and psychological comorbidity on prognosis of chronic low back pain: Longitudinal data from the norwegian hunt study. BMJ open, 7(5). doi:10.1136/bmjopen-2016-015312

Strong, J., & Large, R. (1995). Coping with chronic low back pain: An idiographic exploration through focus groups. The International Journal of Psychiatry in Medicine, 25(4), 371-387. doi:10.2190/H4P9-U5NB-2KJU-4TBN

Undeland, M., & Malterud, K. (2007). The fibromyalgia diagnosis – hardly helpful for the patients? Scandinavian Journal of Primary Health Care, 25(4), 250-255. doi:10.1080/02813430701706568

Wylde, V., Sayers, A., Odutola, A., Gooberman‐Hill, R., Dieppe, P., & Blom, A. (2017). Central sensitization as a determinant of patients’ benefit from total hip and knee replacement. European Journal of Pain, 21(2), 357-365.

Exercise? Who me? Yoga or physiotherapy or education…


Exercise, while one of The Most Important self management approaches for persistent pain, is not an easy sell to someone who is experiencing pain. Especially not if that exercise looks like huffing and puffing, hauling on bits of metal in a gym, or wearing lycra. Not to mention the “sports drinks”…  Those things aside, exercising is a good thing. You heard it from me, and I have declared my body an exercise free zone! The thing is, what kind of exercise, for what purpose, and how to get introduced to it.

Personally I’m a fan of exercise that achieves something else other than “getting fit”. I like gardening, I love dancing, I enjoy cycling (especially to the store to get a GREAT coffee!). Walking the dog is fun. Swimming (especially snorkeling) is awesome! I like my exercise to do more than bring on the endorphins, especially as I don’t get much of that post-exertional analgesia that many people do – and believe me, they do (Ellinson, Stegner, Schwabacher, Koltyn & Cook, 2016). I like my exercise to look like the things I need or want to do, so that when I need to do ’em, I’m in fit state to get on and do ’em.

So what kind of exercise works best? One sage told me “the exercise the person does!” and there is some truth to that, so when I begin talking to someone about exercise, I’m looking for something they can do regularly, that fits into their lifestyle, that makes them feel good, and has some other benefit to them. That benefit might be the social thing – going to a box-fit class with a group of others all bent on getting their fix of play-fighting. It might be the solitary thing – long walks along the beach with the dog for company. It might be the music – in my case, it’s belly dance (and I dare anyone to do a 5 minute shimmy drill while keeping an isolated upper body, a loose shimmy and smile!).

I like the idea of having variety – who says we need to do the same kind of exercise every day? So it’s a wet day and I don’t fancy taking my bike out in the rain, I can turn to my dance practice, or do the dusting, or vacuum the floors. It’s a frosty day and I can go for a brisk walk and take photographs of gorgeous sparkly frosty droplets while Sheba-the-wonderdog huffs steam and sniffs at the local scents. If it’s a warm day, why not head to the pool for a lap or two? If it’s a busy day and I don’t have time, what about some “exercise snacks”? Five minutes of exercise every 25 minutes adds some pretty quickly, so it’s lunges and chair dips and wall presses and shimmy practice in between writing.

Over time we’re seeing more research looking particularly at yoga for persistent pain of all kinds. Yoga comes in many different forms, and in this case I’m guessing the more extreme forms of hot yoga and contortion is not being studied. Some of the studies are appearing in rather eminent journals, like this one from the Annals of Internal Medicine and authored by a very large team including Saper, Lemaster, Delitto and colleagues (2017).

This study is a “non-inferiority” study, looking to establish whether yoga or physiotherapy, or indeed education, can help people living with chronic low back pain. Now I’m not going to do a blow-by-blow analysis of the study, that’s for you to do. What I am going to do is look at what the yoga consisted of – and see why, perhaps, yoga is getting so much research interest. BTW, yoga was found to be non-inferior to physiotherapy, and both yoga and PT were more likely than education to have a clinically meaningful response, although neither yoga nor PT were superior to education.

This is the basic format of the yoga class: Each class began with relaxation and meditation exercises, yoga breathing, and yoga philosophy. It continued with yoga poses and
concluded with relaxation. Pose variations and aids (such as chair, strap, and blocks) accommodated various abilities. Thirty minutes of daily home practice, facilitated by a DVD, a manual, and take-home yoga supplies, was strongly encouraged.

Yoga appeals to many because it seems to begin where people are at – it’s not huffy-puffy, things don’t jiggle, and generally the classes begin and end with the ritual of breathing and meditation. I like the idea of yoga (and yes, I’ve done a class or two!), because it doesn’t involve a lot of gadgets, you can do it alone or in a group, and it feels good. What I don’t like about yoga is the need to get effective and consistent feedback about how well you’re performing the poses, especially in the beginning, which means it can be difficult to do on your own without a teacher.

For people who find exercising both difficult and painful, yoga is a good place to start. I think attending classes is crucial (or at least having an instructor and a mirror!). Learning to use the meditation and breathing is integral to the exercise – and it’s this that I think makes yoga an effective addition to the exercise toolkit. What I’m less sure of is whether it’s better than any other form of exercise – or, in my case, the many different types of movements that I use in my weekly routine. And there’s the rub. As an occupational therapist, exercise is something people choose to do as a form of occupation (valued and meaningful activity). I also enjoy a bunch of other movement-based occupations, and to me these are as valid as yoga or the PT exercises included in this study. What my approach lacks, however, is a researched basis for it.

But here’s the thing: to date the research supporting exercise for people with persistent pain shows modest effects. And those effects are completely lost if the person doesn’t do the exercise. So why not have a wide range of whole-body movement practices to draw on, allowing the person to pick and choose and get out and do something every day, even if it doesn’t fit with our modern notions of what exercise should be?

 

 

Ellingson, L. D., Stegner, A. J., Schwabacher, I. J., Koltyn, K. F., & Cook, D. B. (2016). Exercise Strengthens Central Nervous System Modulation of Pain in Fibromyalgia. Brain Sciences, 6(1), 8. http://doi.org/10.3390/brainsci6010008

Saper, R. B., Lemaster, C., Delitto, A., & et al. (2017). Yoga, physical therapy, or education for chronic low back pain: A randomized noninferiority trial. Annals of Internal Medicine. doi:10.7326/M16-2579

Pacing, pacing, pacing – good, bad, or…?


There’s nothing that pain peeps seem to like more than a good dispute over whether something is good, or not so good for treatment. Pacing is a perennial topic for this kind of vexed discussion. Advocates say “But look at what it does for me! I can do more without getting my pain out of control!” Those not quite as convinced say “But look at how little you’re doing, and you keep letting pain get in the way of what you really want to do!”

Defining and measuring pacing is just as vexed as deciding whether it’s a good thing or not. Pacing isn’t well-defined and there are several definitions to hand. The paper I’m discussing today identifies five themes of pacing, and based this on Delphi technique followed by a psychometric study to ensure the items make sense. The three aspects of pacing are: activity adjustment, activity consistency, activity progression, activity planning and activity acceptance.

Activity adjustment is about adjusting how we go about doing things – approaches like breaking a task down, using rest breaks, and alternating activities.

Activity consistency is about undertaking a consistent amount of activity each day – the “do no more on good days, do no less on bad” approach.

Activity progression refers to gradually increasing activities that have been avoided in the past, as well as gradually increasing the time spent on each task.

Activity planning involves setting activity levels, setting time limits to avoid “over-doing”, and setting meaningful goals.

Finally, activity acceptance is about accepting what can be done, and what can’t, setting realistic goals, adapting targets, and being able to say no to some activities.

In terms of covering the scope of “activity pacing”, I think these five factors look pretty good – capturing both the lay sense of pacing, as well as some of the ideas about consistency and progression.

On to the study itself, conducted by Deborah Antcliffe, Malcolm Campbell, Steve Woby and Philip Keeley from Manchester and Huddersfield.  Participants in this study were attending physiotherapy through the NHS (yay for socialised healthcare! – Let’s keep that way, shall we?!), and had diagnoses of chronic low back pain, chronic widespread pain, fibromyalgia and chronic fatigue syndrome.  They completed the questionnaire either while on a waiting list, or after completing treatment, as a way to generalise findings – so this isn’t a measure of change (at least, not at this point).

Along with the APQ (the Activity Pacing Questionnaire – original name huh?!), participants completed a numeric rating scale, the Chalder Fatigue Questionnaire, Hospital Anxiety and Depression Scale, Pain Anxiety Symptoms Scale, and the Short-Form 12.  Some lovely number crunching was used – hierarchicial (sequential) multiple regression models with five separate multiple regression models of the symptoms of current pain, physical fatigue, depression, avoidance and physical functioning.

One of the confusing problems with  measuring pacing is that people may vary their use of different forms of pacing, depending on their symptoms at the time. So in this analysis, factors like pain and fatigue could be a dependent variable (ie I use pacing techniques and feel less fatigued and I’m in less pain), or they could be a confounding variable (ie I feel sore and tired, so I use these techniques).  Needless to say, the statistical analysis is complex and I don’t have a hope of explaining it!

The results, however, are very intriguing. 257 people completed the questionnaires in full, from an overall number of 311 participants. About half had completed their physiotherapy, while the other half had yet to start (ie waiting list). As usual, more people with low back pain than other conditions, and 2/3 were female. On first pass through the data, to establish correlations for inclusion in the regression  models (did your eyes just glaze over?!), the findings showed activity adjustment was associated with higher levels of current pain, depression, and avoidance, and lower levels of physical function. Activity consistency was associated with lower levels of physical fatigue, depression, and avoidance. and higher levels of physical function. Activity progression was associated with higher levels of current pain. Activity planning was significantly associated with lower levels of physical fatigue, and activity acceptance was associated with higher levels of current pain and avoidance.

Then things changed. As these researchers began adjusting for other independent variables, the patterns changed – Activity adjustment was significantly associated with higher levels of depression and avoidance and lower levels of physical function as before, but after adjustment, the association with pain was no longer significant; instead, it was significantly related to higher levels of physical fatigue. Activity consistency remained significantly associated with lower levels of physical fatigue, depression, and avoidance, and higher levels of physical function, but became significantly associated with lower levels of current pain. There were now no significant partial correlations between activity progression and any of the symptoms, whereas activity planning retained its significant association with lower levels of physical fatigue. Activity acceptance lost its significant association with current pain but retained its significant association with higher levels of avoidance.

Ok, Ok, what does that all mean? Firstly – engrave this on your forehead “Correlation does not mean causation”! What seems to be the case is that different themes or forms of pacing are associated with different symptoms. The items associated with adjusting or limiting activities were generally associated with more symptoms. So the more pain and fatigue a person experiences, it seems the more likely it is for them to choose to limit or adjust how much they do. Pacing themes involving consistency and planning were associated with improved symptoms. Using path analysis, the authors identify that activity adjustment and activity consistency play the most important parts in the relationship  between pacing and symptoms.

The take-home messages from this study are these:

  • We can’t define pacing as a unidimensional process – it seems clear to me that different people describe pacing in different ways, and that this messy definitional complexity makes current studies into the use of pacing rather challenging.
  • It seems that avoiding activities, reducing activities in response to pain or fatigue – the idea of an “envelope” of time/energy that needs to be managed to get through the day – is associated with more severe symptoms. Whether people choose this approach only when their symptoms are severe, and revert to activity adjustment and consistency when in less discomfort is not clear (correlation does not equal causation!)
  • Planning activities seems to be associated with some improved symptoms and the authors suggest that planning activities in advance might help people avoid a “boom and bust” scenario. giving a better shape to the day, a greater sense of control and achievement. Then again, it could be that when people feel better, they’re more able to plan their day, and again this study doesn’t help us much.
  • Activity progression, where the overall amount of activity gradually increases over time, wasn’t associated with either more or less pain and fatigue. I think it’s time we had a good look at whether progression helps people – or doesn’t. Rehabilitation philosophy suggests that it “should” – but do we know?
  • And finally, activity consistency was the aspect of pacing that was associated with improved symptoms – and this is certainly something I’ve found true in my own pain management.

The authors maintain that describing pacing as a multi-faceted construct is the only way forward – clearly we’re not going to agree that “pacing is X” when five different forms of pacing were derived from the Delphi study on which the APQ is based. It seems to me that we could benefit from applying this kind of nuanced definition in more areas than just pacing in pain management!

Antcliff, D., Campbell, M., Woby, S., & Keeley, P. (2017). Activity pacing is associated with better and worse symptoms for patients with long-term conditions. The Clinical Journal of Pain, 33(3), 205-214. doi:10.1097/ajp.0000000000000401

Returning to work, good or bad?- a very complex question


One of the main reasons returning to work is a priority in many healthcare systems is simply that compensation and off-work benefits is the most costly portion of the bill for people with ill health. This naturally leads to a strong emphasis in most rehabilitation, especially musculoskeletal rehabilitation in New Zealand, to help people return to work as soon as practicable. At times the process can be brutal. In my own case, after 18 months of working part-time due to post-concussion symptoms after a “mild” traumatic brain injury, I had the hard word put on me to get back to my job or I’d be sent to work back on the wards (after having spent most of my clinical career working in pain management). Not quite the supportive approach I needed when I was having to sleep for at least an hour every afternoon!

I can well remember the pressure of trying to maintain my work output to the satisfaction of my manager, keep my home responsibilities going (I had teenaged children at the time), manage all the paperwork required just to be part of a rehabilitation system, maintain my relationship which was strained just because I had no energy to play or have fun the way I used to. Oh and I had weekly rehabilitation appointments to top it all off! Not easy to keep your cool when everything seems balanced on a knife-edge.

Yet, despite the challenges of going back to work, most accounts of recovery from musculoskeletal pain find that returning to work forms a crucial element in maintaining long-term gains. The study that sparked this post is a good example: Michael Sullivan and colleagues, set in Montreal, Canada, found that returning to work helps to maintain treatment gains in people with whiplash injury. Of the 110 people enrolled in this study, 73 participants returned to work by the end of one year, while the remaining 37 remained off work. Using regression analysis, the researchers found that the relationship  between return to work and maintaining treatment goals remained significant even when confounds such as pain severity, reduced range of movement, depression and thinking the worst (catastrophising) were controlled. What this means is that something about those who returned to work seemed to help them achieve this, and it wasn’t the usual suspects of low mood or that the injury was more severe. What is even more striking is that those who didn’t return to work actually reported worsening symptoms.

There are plenty of arguments against this finding: could it be that those who didn’t return to work just didn’t respond as well to the treatment in the first place? Well – the authors argue no, because they controlled for the things that should have responded to treatment (eg range of movement, mood). Participants in the study returned to work 2 months on average after completing their treatment, and final measurement was on average 10 months later suggesting that it was something to do with being at work that made a difference.

In their discussion, the authors suggest that perhaps those who didn’t return to work were overall less physically active than those who did, compromising their recovery potential. They also note that being out of work is known to be associated with poorer mental health, so perhaps that explains the difference at the end of the trial period. In addition, they point out that perhaps ongoing stress related to having to handle disability claims processes, perhaps even the financial stress of being unable to work might have been influential.

It’s this last point that I think is interesting. There is no doubt that people who encounter the disability systems that fund their treatment and replace their income feel like their autonomy and independence has gone. They feel their world is being manipulated at the whim of case managers, treatment providers, assessing doctors, and even their family.  A sense of injustice can be detrimental to outcomes for people with whiplash, as Sullivan and colleagues showed some years ago (Sullivan, Thibault, Simmonds, Milioto et al 2009), and we know also that social judgements made about people who experience persistent pain are often negative and exert an influence on the experience of pain itself (Bliss, 2016; Schneider et al, 2016).

Working is really important to people – even in a job you don’t especially enjoy, there are important reasons you keep going (even if it’s only for the money! Money in the hand means food for you and yours, power for the lighting and heating, and even a little bit left over for jam on your bread!). In addition to the money, the most commonly asked question when you’re introduced to someone is “and what do you do for a job?” It’s a way of categorising a person, as much as we hate that idea. Work gives us social contact, routine, purpose and allows us a way to demonstrate competence. Without the anchor of working, many people who live with persistent pain feel the burden of social judgement “who are you?”, of ongoing bureaucracy (filling in paperwork), of repeated assessments to justify not being at work, of constantly being asked to attend appointments, of never feeling like time is their own. Balancing the demands of a system that judges you negatively because you are “unfit” against the demands of family and your own needs is an incredibly difficult process – but then again, so is the process of returning to a job where you fear you’ll fail and experience That Pain Again, and where, if you fail, you could lose that job entirely.

I don’t have an answer to how we can make this process easier. I do know that early return to work can be positive if handled well – but handled poorly, can be an extremely unpleasant and stressful process. Vocational rehabilitation providers need to understand both acute and persistent pain. They also need to carefully assess the psychosocial aspects of a job, not just the biomechanical demands. And someone needs to represent the needs of the person living with persistent pain and help them balance these demands carefully.

 

Bliss, Tim VP, et al. (2016)”Synaptic plasticity in the anterior cingulate cortex in acute and chronic pain.” Nature Reviews Neuroscience .

De Ruddere, Lies, et al. (2016)”Patients are socially excluded when their pain has no medical explanation.” The Journal of Pain 17.9 : 1028-1035.

McParland, J. L., & Eccleston, C. (2013). “It’s not fair”: Social justice appraisals in the context of chronic pain. Current Directions in Psychological Science, 22(6), 484-489.

Schneider, Peggy, et al. “Adolescent social rejection alters pain processing in a CB1 receptor dependent manner.” European Neuropsychopharmacology 26.7 (2016): 1201-1212.

Sullivan, M. J., Thibault, P., Simmonds, M. J., Milioto, M., Cantin, A. P., Velly, A. M., . . . Velly, A. M. (2009). Pain, perceived injustice and the persistence of post-traumatic stress symptoms during the course of rehabilitation for whiplash injuries. Pain, 145(3), 325-331.

Sullivan, M., Adams, H., Thibault, P., Moore, E., Carriere, J. S., & Larivière, C. (2017). Return to work helps maintain treatment gains in the rehabilitation of whiplash injury. Pain, 158(5), 980-987. doi:10.1097/j.pain.0000000000000871

Targeting the people who need it most


A couple of things came to mind today as I thought about this post: the first was an article in the local newspaper about a man complaining that the government is “promoting disability” because he couldn’t get surgery for a disc prolapse – and the pain was affecting his ability to work. The second was how to direct the right treatment at the right person at the right time – and how we can be derailed by either wholesale over-servicing “everyone needs treatment X”, or by overburdening people with assessment just to give a fairly basic treatment.

Now with the first man, I don’t know his clinical situation – what I do know is that there are many people every day who must learn to live with their pain because there simply is not an effective treatment of any kind, and that amongst these people are those go on to live wonderful lives despite their pain. I wonder if this man has ever been offered comprehensive self management for while he waits for his surgery. Whether the government could spread some funding away from surgery as the primary option for such pain problems – and instead provide better funding for the wider range of approaches offered through the interdisciplinary pain management centres (approaches which include injection procedures, physiotherapy, psychology, occupational therapy and medications). When there is an effective treatment (and this is arguable in the case of disc prolapse – in fact, it’s difficult to know whether even MRI imaging can give a clear indication of who might respond best to what treatment (Steffens, Hancock, Pereira et al, 2016), we should be able to give it, provided it fits within our country’s health budget. Ahh – that’s the problem, isn’t it… expensive treatments mean fewer people can get basic treatment. And with lumbar disc prolapse, the evidence for surgery is less favourable than many people recognise (Deyo & Mirza, 2016) – they state:

“Patients with severe or progressive neurologic deficits require a referral for surgery. Elective surgery is an option for patients with congruent clinical and MRI findings and a condition that does not improve within 6 weeks. The major benefit of surgery is relief of sciatica that is faster than relief with conservative treatment, but results of early surgical and prolonged conservative treatment tend to be similar at 1 year of follow-up. Patients and physicians should share in decision making.”

So here we have a person with lots of pain, experiencing a great deal of distress, and reducing his work because of pain and disability. My question now (and not for this person in particular) is whether being distressed is equivalent to needing psychological help. How would we know?

There’s been a tendency in pain management to bring in psychologists to help people in this kind of situation. Sometimes people being referred for such help feel aggrieved: “My problem isn’t psychological!” they say, and they’re quite correct. But having a problem that isn’t psychological doesn’t mean some psychological help can’t be useful – unless by doing so, we deny people who have serious psychological health problems from being seen. And in New Zealand there are incredible shortages in mental health service delivery – in Christchurch alone we’ve had an increase in use of mental health services of more than 60% over the past six years since the massive 2010/2011 earthquakes (The Press).

People living with persistent pain often do experience depression, anxiety, poor sleep, challenges to relationships and in general, feeling demoralised and frustrated.  In a recent study of those attending a specialist pain management centre, 60% met criteria for “probable depression” while 33.8% met criteria for “severe depression” (Rayner, Hotopf, Petkova, Matcham, Simpson & McCracken, 2016). BUT that’s 40% who don’t – and it’s my belief that providing psychological services to this group is allocating resources away from people who really need it.

So, what do we do? Well one step forward might be to use effective screening tools to establish who has a serious psychological need and who may respond just as well to reactivation and return to usual activities with the support of the less expensive (but no less skilled) occupational therapy and physiotherapy teams. Vaegter, Handberg, & Kent (in press) have just published a study showing that brief psychological screening measures can be useful for ruling out those with psychological conditions. While we would never use just a questionnaire for diagnosis, when combined with clinical assessment and interview, brief forms of questionnaires can be really helpful for establishing risk and areas for further assessment. This study provides some support for using single item questions to identify those who need more in-depth assessment, and those who don’t need this level of attention. I like that! The idea that we can triage those who probably don’t need the whole toolbox hurled at them is a great idea.

Perhaps the New Zealand politicians, as they begin the downhill towards general elections at the end of the year, could be asked to thoughtfully consider rational distribution of healthcare, and a greater emphasis on targeted use of allied health and expensive surgery.

 

Deyo, R. A., & Mirza, S. K. (2016). Herniated Lumbar Intervertebral Disk. New England Journal of Medicine, 374(18), 1763-1772.

Hahne, A. J., Ford, J. J., & McMeeken, J. M. (2010). Conservative management of lumbar disc herniation with associated radiculopathy: A systematic review. Spine, 35(11), E488-504.

Koffel, E., Kroenke, K., Bair, M. J., Leverty, D., Polusny, M. A., & Krebs, E. E. (2016). The bidirectional relationship between sleep complaints and pain: Analysis of data from a randomized trial. Health Psychology, 35(1), 41-49.

Rayner L, Hotopf M, Petkova H, Matcham F, Simpson A, McCracken LM. Depression in patients with chronic pain attending a specialised pain treatment centre: prevalence and impact on health care costs. Pain. 2016;157(7):1472-1479. doi:10.1097/j.pain.0000000000000542

Steffens, D., Hancock, M.J., Pereira, L.S. et al.(2016) Do MRI findings identify patients with low back pain or sciatica who respond better to particular interventions? A systematic review. European Spine Journal 25: 1170. doi:10.1007/s00586-015-4195-4

Vaegter, H. B. P., Handberg, G. M. D., & Kent, P. P. Brief psychological screening questions can be useful for ruling out psychological conditions in patients with chronic pain. Clinical Journal of Pain.

…and now what we’ve all been waiting for: What do to about central sensitisation in the clinic


For the last couple of weeks I’ve posted about central sensitisation; what it is, and how to assess for it. Today I’m going to turn to the “so what” question, and talk about what this might mean when we’re in the clinic.  Remember that most of this material comes from Jo Nijs’ recent talks at the New Zealand Pain Society.
Firstly, remember that pain is an experience that people have, underpinned by neurobiology, but also, depending on the level of analysis, on interactions with others, on systems and how they work, on culture, on individual experiences, and of course, on interacting within a body within an environment or context. Everything I say from here on is based on these assumptions.

The first point Jo Nijs makes is that when we know a bit more about the neurobiology of persistent pain associated with central sensitisation, we can use this knowledge wisely when we help someone make sense of their pain. This doesn’t mean wholesale and broadcast “I-will-tell-you-all-I-know-about-pain-neurobiology-because-I-know-you-need-to-know-it-because-I-know-it-and-think-it’s-important” which is, truth to tell, a lot more about the know-it-all than the person in front of them! We need to earn the right to give information – that means establishing that we’ve heard the other person’s story and the current meanings they’ve made from their experience. It also means asking permission to share new information. It means thinking about WHY we want to share new information.

So what if the person doesn’t use the same groovy language we use to describe his or her understanding?! So what if they’ve got some of the newer ideas slightly skewed. In the end, what’s important is that the person understands these things:

  • Pain isn’t a direct reflection of what’s happening in the tissues.
  • Pain can be influenced by many things, some of which are physical forces (heat, pressure and so forth), some of which are ideas, and some are emotions. And there are a bunch of other variables that can influence the experience, including what else is going on around the person.
  • The brain is intimately involved with our experience of pain, and it’s a two-way street from body to brain and brain to body.
  • Persistent pain is more about neurobiology than tissue damage per se (but not exclusively about neurobiology).

Our job is to make sure the person understands these things, rather than our job being about “educating” people. The end result matters, rather than any particular process.

If we look at the evidence for helping people reconceptualise their pain, there’s plenty to show that this approach is useful – it’s been a key tenet of a self-management cognitive behavioural approach to pain management since at least the late 1970’s. The later research (from Butler, Moseley and Louw et al) is simply looking at this approach within a slightly different cohort and in a different context. Rather than being integrated with an interdisciplinary pain management programme, research from these guys shows that physiotherapists (in particular) can deliver this kind of information very effectively – and that it helps reduce the fear and subsequent efforts to avoid pain (such as not moving, seeking healthcare, and being worried about pain). Yay!

It’s true that there are many different ways to influence the descending modulatory system, and release endorphins. One of them is to help people understand their pain and be more confident about moving. Another is to place hands on the person – hence massage therapy, manual therapies, manipulations and so on. Nijs believes hands on therapy has best effect after you’ve gone through some of the reconceptualisation that’s often needed (Bishop, Torres-Cueco, Gay, Lluch-Girbes, Beneciuk, & Bialosky, 2015).

Similar arguments can be made for considering sleep management and stress management as an integral part of pain management. (To be perfectly honest, I always thought this was part of what we did…). So here’s the argument: we know most people with persistent pain experience rotten sleep. We also know that people are stressed by their experience of pain. Because poor sleep is associated with increased activation of glia in the prefrontal cortex, amygdala and hippocampus, and therefore are pro-inflammatory, pain is often increased after a poor night’s sleep. Sleep medications interfere with the sleep architecture, so it’s useful to consider nonpharmacological approaches to sleep management.

Three strategies to consider:

  • CBT for insomnia – here’s one resource to use
  • ACT or acceptance and commitment therapy – I’ve written a great deal about ACT, just use the search function on this blog for more
  • Exercise – OMG yes, exercise is effective! (just not right before bedtime, kthx)

Stress management is tougher. We can’t avoid experiencing stress – and neither can we live in a bubble where we don’t ever get exposed to stress. Instead, we probably all could do with learning multiple ways of managing stress. Things like realistic evaluations of the situation, increasing our capabilities for regulating our response to stress via biofeedback if need be, and using mindfulness as a strategy for being with stress instead of fighting against it, or folding beneath it.

I haven’t cited many references in this post – not because there aren’t many, but because there are SO many! And I’ll post more next week when I start looking at the rather sexy neurobiological examinations of processes used in pain management for years (yes, we’ve been doing it for a long time, we now have great explanations for how these things might work – though effect sizes are still small.)

 

Bishop, M. D., Torres-Cueco, R., Gay, C. W., Lluch-Girbés, E., Beneciuk, J. M., & Bialosky, J. E. (2015). What effect can manual therapy have on a patient’s pain experience?. Pain, 5(6), 455-464.

 

Does central sensitisation matter?


In my last post I discussed some of the mechanisms thought to be involved in central sensitisation, and while many of the details remain pretty unknown, I think the general conclusion is that yes, it really is a thing. What do I mean by central sensitisation? Well, it’s curious, it can refer to the processes at spinal and brain levels that seem to reduce the usual descending inhibitory mechanisms, expand the areas in which neural activity takes place, and allows increased information flow to eventually reach conscious awareness. At the same time it can refer to the experience in which a person feels greater pain than anticipated, given the degree of input; pain that is distributed more widely than anticipated, given the degree of input; and/or pain that lasts longer than we’d expect, given the degree of input (Woolf, 2011). BTW most of this post is derived from talks given by Pro Jo Nijs at the recent New Zealand Pain Society Conference.

The question now is whether this really matters. After all, nociceptor inputs can trigger a prolonged but reversible increase in central nociceptive pathways – if they’re reversible, just eliminate the original nociceptive input, and voila! The sensitisation is gone. What we know, however, is that in many cases the tendency towards having long-term increased sensitivity remains, or was perhaps always present.

Well, unfortunately if someone does tend to have greater activity in the central nervous system, then it has the potential to add enormously to poor outcomes if he or she decides to have surgery. For example, individuals with this tendency experience poorer outcomes after total knee replacement; and after shoulder surgery; but not after hip-joint replacement surgery. Testing in these cases was conducted using conditioned pain modulation which involves people undergoing painful testing – when they’re already in pain! Brave souls. You can see why it’s not a popular testing procedure in mainstream surgical situations.

Adding to the view that central sensitisation matters clinically, Ferrandiz and colleagues (2016) found that central sensitisation mediates the treatment effects in people with low back pain; Jull and colleagues (2007) found the same for neck pain after whiplash; Coombes and colleagues (2015) found the same for people with chronic tennis elbow.  It seems that central sensitisation is associated with greater pain catastrophising, slower movements, higher pain reporting, poorer functioning, increased perception of pain, and fear of moving.

The question now is how best to assess for the presence of this phenomenon. Given that most people won’t want to undergo conditioned pain modulation (not to mention the need for testing equipment and skilled technicians to administer the test!), what’s needed is a reasonably simple way to identify those who have the characteristics of central sensitisation so we can plan for, and manage it, more effectively.

Nijs and the Pain in Motion Research Group published the first set of criteria in 2014, from an epidemiological perspective. This classification approach involves first excluding neuropathic pain – and the group propose using IASP diagnostic criteria for neuropathic pain (see Haanpaa & Treede, 2010). If the problem is neuropathic pain (where there is a clear lesion of the nerve), then it’s managed accordingly (although we really don’t have great treatments for this kind of pain, either!).

Then they propose an algorithm which helps to clarify whether the problem is central sensitisation or “something else”.

The first question is whether the person identifies they have “disproportionate pain experience” – now this I have a problem with, because what is a “proportionate” pain experience? Given how fluid our experience of pain can be, and how poorly the experience correlates with what’s going on in the tissues, I find this a bit tough to use as a clear-cut indicator. Nevertheless, it’s the first question asked in this algorithm…

The next question relates to the person experiencing diffuse pain distribution (or, perhaps, wider spread than expected). If this is the case, eg someone has a grazed knee, but pain is experienced all over the entire leg, then it’s identified as central sensitisation. If the result is more like pain just above the knee to just below, then it’s somewhat equivocal, so the authors suggest the person completes the Central Sensitisation Inventory. This is a questionnaire I’ve discussed in the past. I’m no nearer to establishing whether it really is a useful measure than when I wrote that blog, but the measure continues to be used, and research is ongoing. Certainly, Jo Nijs and group seem to think the measure holds promise and might help to classify those at greater risk of developing problems with pain if they proceed to surgery.

So, to summarise, while the mechanisms involved in central sensitisation are still being discovered, and it’s challenging to know where normal processes end and abnormal ones begin, it definitely seems to be a clinical phenomenon affecting not only those without peripheral nociception (eg migraine), but also those with clearcut peripheral problems like osteoarthritis. Central sensitisation processes seem to underpin some of the most problematic pain problems we know of, and can get in the way of recovery even when peripheral nociceptive input has been removed – 18% of total knee-joint replacements are revised because of ongoing pain, and this pain doesn’t seem to improve after subsequent surgery (NZ National Joint Registry). There’s confusion about language – does the term refer to the mechanisms thought to be involved, or does it refer to the experience described by people? And assessing it is challenging – either go through complex and painful testing, or complete a questionnaire that may confound distress about health (and subsequent hypervigilance about body symptoms) with pain and other responses that might represent the presence of central sensitisation processes being invoked.

More challenging still is what do we do once central sensitisation is identified? Are our treatments any good? That, folks, will be explored in the next enthralling episode on Healthskills!

 

Baert, I., Lluch, E., Mulder, T., Nijs, J., Noten, S., & Meeus, M. (2016). Does pre-surgical central modulation of pain influence outcome after total knee replacement? A systematic review. Osteoarthritis and Cartilage, 24(2), 213-223.

Haanpää M, Treede RD. Diagnosis and classification of neuropathic pain. Pain Clinical Updates 2010; XVII.

Nijs, J., Torres-Cueco, R., van Wilgen, P., Lluch Girbés, E., Struyf, F., Roussel, N., . . . Vanderweeën, L. (2014). Applying modern pain neuroscience in clinical practice: Criteria for the classification of central sensitization pain. Pain Physician, 17(5), 447-457.

Valencia, C., Fillingim, R. B., Bishop, M., Wu, S. S., Wright, T. W., Moser, M., . . . George, S. Z. (2014). Investigation of central pain processing in post-operative shoulder pain and disability. The Clinical Journal of Pain, 30(9), 775.

Woolf, C. J. (2011). Central sensitization: Implications for the diagnosis and treatment of pain. Pain, 152(3 Suppl), S2-15.

Wylde, V., Sayers, A., Odutola, A., Gooberman‐Hill, R., Dieppe, P., & Blom, A. (2017). Central sensitization as a determinant of patients’ benefit from total hip and knee replacement. European Journal of Pain, 21(2), 357-365.

Is central sensitisation really a thing?


It seems odd to me that there’s much argument about central sensitisation in pain circles. I thought the idea of central sensitisation was well-established based on research from some years ago – but apparently there are still arguments about its relevance, and lots of debate about how to identify it clinically. This post is based mainly on a presentation by Jo Nijs from Pain in Motion, at the recent NZ Pain Society meeting in Nelson. In this post I want to briefly review the material presented by Jo suggesting that central sensitisation is a thing. I’ll write more about assessment in a future blog, or this post will be the longest ever!

Firstly, what is it and why should it matter? Researchers have long been aware that when a nerve is repeatedly stimulated, in future stimulation it will respond for longer and with more intensity – this is called long-term potentiation. Recently, the contribution of glial cells to this situation has been identified (remember glia? Those little cells whose purpose no-one really knew? Turns out they release gliotransmitters that circulate throughout the spinal cord and allow information to be transmitted widely, far from the original source of stimulation – see Kronschlager, Drdla-Schutting, Gassner, Honsek et al, (2016). Glial cells occur widely throughout the central nervous system, and while LTP is a process we’ve known about in the CNS for some time – we’ve known because this is how “memories” are formed (remember “nerves that fire together wire together”? Pathways that frequently activate develop the tendency to continue to activate together) – we’ve perhaps not been aware that this occurs in the spinal cord as well. So, LTP occurs in both the spinal cord and the brain, and there is more than one way this process is facilitated. Glial cells are one. Central sensitisation involves this process of long-term potentiation across and amongst pathways within our nervous system – it means information from peripheral regions like your big toe are more likely to be transmitted to areas in the brain responsible for attending and responding to threatening information.

Why does this matter? Well, if we think of ourselves as a finely tuned homeostatic machine, one that wants to remain in a stable state, we can think of two systems balanced with one another. One system works to facilitate information transmission (nociceptive facilitation), while the other works to reduce or modulate this transmission (endogenous hypoalgesia). If we continue with the machine analogy, we want to know about “trouble” as soon as possible – so our nociceptive facilitatory system is like an accelerator, working promptly to make sure we know about the state of play very quickly. If you’ve ever driven a race car, you’ll know how twitchy the accelerators are! The brakes on this system is our endogenous opioid system which reduces the influence of the nociceptive system so we can keep moving forward. If the brakes fail, for whatever reason, in a race car we’ll burst forward! Similarly, if the endogenous modulatory system fails, for whatever reason, far more information ascends to relevant regions in the brain for interpretation – and ouch.

What sorts of things enhance connectivity between areas of the brain that deal with nociceptive information? Well, this is where things get all woolly and psychosocial for a while (sorry guys!). From many fMRI studies, it’s possible to establish that “pain catastrophising” or the tendency to brood on pain, feel helpless about it, and regard the pain as seriously intense activates brain areas like the dorsolateral prefrontal cortex, the anterior cingulate cortex, and the insula, which in term reduces the efficiency of the opioid analgesic system (that endogenous opioid system), makes it harder to distract attention from the pain, and increases facilitation (ie the transmission of nociceptive information from lower CNS to higher). In other words, this very psychological construct has a biological component to it.

Central sensitisation has been identified in many different pain problems, ranging from osteoarthritis in the knee (Akinci, Al Shaker, Chang, et al, 2016), post-cancer pain (Lam, 2016), shoulder pain (Sanchis, lluch, Nijs, Struyf & Kangasperko, 2015), and yes, those messy complicated ones like whiplash (Coppieters, Ickmans, Cagnie, Nijs, et al, 2015), low back pain (Sanzarello, Merlini, Rosa, Perrone et al, 2016) and fibromyalgia (Walitt, Ceko, Gracely & Gracely, 2016). Rates of central sensitisation vary from 10% in shoulder pain to 100% in fibromyalgia. For some good reading on central sensitisation in these disorders, take a look at the references I’ve cited.

So yes, central sensitisation is a thing, and it results in increased pain experiences that last longer and spread. Why do some people experience while others don’t? Now we’re venturing into rather more speculative areas, but some findings seem clinically useful. People who have, in their early years, experienced physical and/or psychological trauma, those who tend to catastrophise or have unhelpful beliefs (often inaccurate beliefs) about their pain,  those who have poor sleep, and those who have an elevated stress response seem more likely to have pain that fits with what we’d expect with central sensitisation (See Nijs & Ickmans, 2014).

Why does this occur? Well, stress increases release of glutamate and this in turn increases CNS excitability (makes sense – let’s react faster to everything, at least for a short time). At the same time, stress reduces GABA and serotonin, and as a result inhibition is reduced (the brakes come off). If we add microglial activity to the mix (remember that’s going to increase the connectivity between neurones), and if we add ongoing release of adrenaline in because the stress has been continuing for a while, we’re going to end up with activated glial activity in the prefrontal cortex, amygdala and hippocampus, all important areas for detecting salience and making decisions to act. These glial cells release chemicals known to increase neuroinflammation, reducing hippocampal activity (ultimately reducing volume of neurones in this area), increasing the size of the amygdala (which means it’s more capable of responding to threat), and reducing the prefrontal cortex size, reducing the capacity to make considered decisions (Kregel, Meeus, Malfliet et al, 2015). Ew… nasty! In longterm stressful situations, it seems our brains adapt – and not in a helpful way when it comes to experiencing pain. Whatever you do DON’T say to your patients  “Oh and by the way, your back pain means your brain is inflamed and parts of your brain are shrinking” – this is NOT helpful!

Next post I’ll discuss assessing for central sensitisation – but before I do, remember that central sensitisation is not the only factor at play in ongoing pain. In fact, some people don’t seem to develop central sensitisation even with ongoing nociception from either disease processes, or inflammation. We don’t really know why. What we do know is that simply treating peripheral nociceptive input when central sensitisation is present may fail to help the person – so keeping an eye out for it is important.

 

Akinci, A., Al Shaker, M., Chang, M. H., Cheung, C. W., Danilov, A., Jose Duenas, H., . . . Wang, Y. (2016). Predictive factors and clinical biomarkers for treatment in patients with chronic pain caused by osteoarthritis with a central sensitisation component. International Journal of Clinical Practice, 70(1), 31-44.

Coppieters, I., Ickmans, K., Cagnie, B., Nijs, J., De Pauw, R., Noten, S., & Meeus, M. (2015). Cognitive performance is related to central sensitization and health-related quality of life in patients with chronic whiplash-associated disorders and fibromyalgia. Pain Physician, 18(3), E389-401.

Kregel, J., Meeus, M., Malfliet, A., Dolphens, M., Danneels, L., Nijs, J., & Cagnie, B. (2015). Structural and functional brain abnormalities in chronic low back pain: A systematic review☆. Paper presented at the Seminars in arthritis and rheumatism.

Kronschläger, M. T., Drdla-Schutting, R., Gassner, M., Honsek, S. D., Teuchmann, H. L., & Sandkühler, J. (2016). Gliogenic ltp spreads widely in nociceptive pathways. Science, 354(6316), 1144-1148. doi:10.1126/science.aah5715

Lam, D. K. (2016). Emerging factors in the progression of cancer-related pain. Pain Management, 6(5), 487-496.

Nijs, J., & Ickmans, K. (2014). Chronic whiplash-associated disorders: To exercise or not? The Lancet, 384(9938), 109-111.

Sanchis, M. N., Lluch, E., Nijs, J., Struyf, F., & Kangasperko, M. (2015). The role of central sensitization in shoulder pain: A systematic literature review. Seminars in Arthritis & Rheumatism, 44(6), 710-716.

Sanzarello, I., Merlini, L., Rosa, M. A., Perrone, M., Frugiuele, J., Borghi, R., & Faldini, C. (2016). Central sensitization in chronic low back pain: A narrative review. Journal of Back & Musculoskeletal Rehabilitation, 29(4), 625-633.
Walitt, B., Ceko, M., Gracely, J. L., & Gracely, R. H. (2016). Neuroimaging of central sensitivity syndromes: Key insights from the scientific literature. Current Rheumatology Reviews, 12(1), 55-87.

… a little more about Pain Catastrophising subscales


I’ve been writing about the Pain Catastrophising Scale and how to use this instrument in clinical practice these last two posts here and here because the construct of catastrophising (thinking the worst) has become one of the most useful to help identify people who may have more distress and disability when dealing with pain. Today I want to continue with this discussion, but looking this time at a large new study where the subscales magnification, rumination and hopelessness have been examined separately to understand their individual impact on pain severity and disability.

Craner, Gilliam and Sperry looked at the results of 844 patients with chronic pain prior to taking part in a group programme (a heterogeous sample, rather than a single diagnosis, so this group probably look at lot like those admitted to high intensity tertiary chronic pain management services such as Burwood Pain Management Centre here in Christchurch).  Most of the participants were female, European/white and married, and had chronic pain for an average of 10.7 years. Just over half were using opioid medication to manage their pain.

Along with the PCS, participants also completed some very common measures of disability (Westhaven-Yale Multidimensional Pain Inventory – MPI) and quality of life (SF-36), and the CES-D which is a measure of depression.

Now here comes some statistical analysis: multiple hierarchical regression! Age, sex, duration of pain and use of opioids were entered into the equation and found to account for only 2.0% variance of the pain severity subscale of the MPI – but once the PCS was added in (subscales entered separately) an additional 14% of the variance was accounted for, but the helplessness subscale was the only one to contribute significantly to the overall variance.

When Pain Interference was  entered as the dependent variable, all the same demographic variables as above contributed a meagre 1.2% of the variance, but when the Pain Severity subscale scores were added, 25.5% of the variance was explained – while the combined PCS subscales contributed 6.5% of the variance. Again, helplessness was the only subscale to contribute to Pain Interference.

Moving to quality of life – the physical subscale of the SF-36 was used as the dependent variable, and once again the demographic variables accounted for only 1.5% variance in physical QOL, with Pain Severity accounting for 23%. PCS subscales contributed only 2.6% of the variance, with only the magnification subscale being identified as a unique contributor. When the mental health subscale was used, again demographics only accounted for 1.2% of variance, with pain severity accounting for 12.4% of the variance. This time, however, the PCS subscales contributed 19.5% of the variance with both Magnification and Helplessness contributing to the variance.

Finally, examining depression, demographics contributed a small amount of variance (3.3%), with pain severity additing 9.8% of variance. The PCS subscales were then entered and contributed a total of 21% to the prediction of depression with both Magnification and Helplessness contributing to the overall depression variance.

The so what factor

What does this actually mean in clinical practice? Well first of all this is a large group of patients, so we can draw some conclusions from the calculations – but we need to be a little cautious because these participants are a group who have managed to get into a tertiary pain management facility. They’re also a group with a large percentage using opioids, and they were pretty much all European – and from North America, not New Zealand. I’m not sure they look like the people who might commonly come into a community-based facility, or one where they’d be referred directly from a GP or primary care centre.

At the same time, while this group may not look like the people most commonly seen for pain management, they share some similar characteristics – they tend to magnify the “awfulness” of pain, and then feel helpless when their pain is bothering them. Surprisingly, I thought, ruminating or brooding on pain wasn’t a unique contributor and instead the helplessness scale contributed the most to pain severity, pain-related interference (disability associated with pain), poor mental health quality of life, and low mood, while magnification scale contributed to poorer physical health quality of life, mental health quality of life and low mood.

What this means for practice

The authors suggest that the construct measured by the helplessness subscale might be a factor underlying poor adaptation to life’s difficulties in general, leading to passivity and negative emotions. They also suggest that magnification might be a unique contributor to perceiving obstacles to doing the things we need to do every day, while hopelessness might mean people are less likely to participate in enjoyable activities and then in turn contribute to feeling low.

Importantly, the authors state: “We offer that simply collapsing the 3 dimensions of this phenomenon (ie, rumination, magnification, helplessness) may actually conceal nuanced relationships between specific dimensions of catastrophizing and outcomes that would might inform treatment approaches.” Looking at the overall scores without thinking about the subscales is going to give you less information to use for individualising your treatment.

In a clinical setting I’d be reviewing the individual subscales of the PCS alongside both disability and mood measures to see if the suggested relationships exist in the scores this person has given.

I’d be taking a look at the repertoire of coping strategies the person can identify – and more, I’d be looking at how flexibly they apply these strategies. Extending the range of strategies a person can use, and problem-solving ways to use these strategies in different activities and contexts is an important part of therapy, particularly occupational therapy and physiotherapy. Another approach you might consider is helping people return to enjoyable activities that are within their tolerance right here, right now. By building confidence that it’s possible to return to things that are fun we might counter the effects of helplessness, and help put pain back where it belongs – an experience that we can choose to respond to, or not.

I’d also be taking a look at their tendency to avoid feeling what their pain feels like, in other words I’d like to see if the person can mindfully and without judging, complete a body scan that includes the areas that are painful. This approach is intended to help people notice that alongside the painful areas are other nonpainful ones, and that they can successfully be with their pain and make room for their pain rather than attempting to block it out, or over-attend to it. The way mindfulness might work is by allowing people to experience the sensations without the judgement that the experience is bad, or indicates some terrible catastrophe. It allows people to step back from the immediate reaction “OMG that’s BAD” and to instead take time to view it as it actually is, without the emotional halo around it.

Pain catastrophising is a useful construct – but I think we need to become more nuanced in how we use the scores from the questionnaire.

Craner, J. R., Gilliam, W. P., & Sperry, J. A. (2016). Rumination, magnification, and helplessness: How do different aspects of pain catastrophizing relate to pain severity and functioning? Clinical Journal of Pain, 32(12), 1028-1035.