Health

Occupational therapists’ knowledge of pain


I am mightily bothered by health professionals’ lack of knowledge about pain. Perhaps it’s my “teacher” orientation, but it seems to me that if we work in an area, we should grab as much information about that area as possible – and pain and pain management is such an important part of practice for every health professional that I wonder why it’s so often neglected. So, to begin exploring this, I completed a search looking at occupational therapists’ knowledge of pain – and struck gold,  kinda.

Angelica Reyes and Cary Brown conducted a survey of Canadian occupational therapists, to explore how well occupational therapists knew their stuff.

Members of the Canadian Association of Occupational Therapists were asked to participate and a total of 354 therapists (mainly from Ontario, Alberta and Nova Scotia) took part. Curious that few were from British Columbia where I know of quite a few occupational therapists working in the area, but there you have it.  Over half of the respondents had 10 years or less experience – so they were fairly recent graduates and should reflect a “current” educational bias. Only 5% of the total number of members of CAOT responded, so this is a fraction of the occupational therapists working in Canada – but you’d think the motivated (ie knowledgeable) would be more likely to respond than those who don’t work in the area….

What they found was consistent with previous studies (prior to 2000) showing that these respondents, who were surveyed using the City of Boston’s Rehabilitation Professionals’ Knowledge and Attitude Survey (Rochman & Herbert, 2015), had disturbing “potential knowledge gaps” in the following areas:

  • children’s ability to feel pain;
  • use of analgesics in orthopedic pain
  • use of nondrug treatments
  • thermal modalities
  • prevalence of malingering
  • impact of therapists’ values on assessment of veracity
  • mind/body dualism in chronic pain
  • measurement of pain intensity
  • effect of under-treatment on chronicity
  • prevalence of patients who over-report pain
  • prevalence ofpatients who are likely to become addicted if treated with opioids.

Of particular concerns was 45.7% of participants believed that malingering is common; 38% believed that pain intensity can be objectively measured, 39.7% believed people with pain over-report their pain, and 59.8% believed that opioid addiction is likely to occur in more than 5% of the patient population.

OUCH!

So, it seems that these occupational therapists had some very outdated ideas about pain, and in particular, seem to have missed the point that because pain is a biopsychosocial experience, we have no way to determine whether someone is “faking” – or malingering.

Now, I will lay good money on a bet that if we were to carry out this very same survey amongst any other health profession, we’d still arrive at these rather unsavoury findings. Folks, I live in a pain nerd bubble and I still hear these kinds of discussions amongst knowledgeable health professionals, so it’s unsurprising that so many people hold these beliefs. Beliefs that will hamper developing good relationships with the people we want to help, and beliefs that fly in the face of what we know about pain.

I am SO not pointing the finger at Canadian occupational therapists, neither am I pointing the finger at my profession alone. I think this lack of understanding reflects many things:

  1. Pain is a complex experience, and the legacies of ancient models lingers everywhere (dualism, medical model, reductionism, etc);
  2. We devote very little time in our professional training to learning about pain – and often, it’s limited to “here is the nociceptive system”;
  3. The research around pain has exploded over the last 15 years – it’s hard to keep up, which is why I blog;
  4. The problem of persistent pain is under-estimated, so if a person works in paediatrics, older person’s health, neurology, brain injury, spinal cord injury – it’s quite probable that pain is almost completely ignored, because “it’s not relevant”. After all, pain is something for specialist pain services, yes? NO
  5. Prevailing attitudes within the healthcare community are that pain is a difficult area to understand – and “should” be treated with medication or surgery otherwise….

You can see that this year’s IASP Global Year for Excellence in Pain Education has much to do.

Did you know that IASP have produced NINE comprehensive curricula – including occupational therapy  (thank you to Emeritus Professor Jenny Strong, Professor Cary Brown and Dr Derek Jones for developing this wonderful resource). This means there is no reason for us not to begin integrating this import area of practice into our undergraduate training.

Research examining occupational therapy’s contribution within pain management is in its infancy – but oh how my occupational therapy heart went pit-a-pat when, at the Australian and New Zealand Pain Society Scientific Meeting I presented alongside two other occupational therapists with PhD’s (or nearly there!) to a room full of clinicians, not just occupational therapists. While we have little specifically occupational therapy research, occupational therapists have been and are continuing to be part of research efforts around the world. And what clinicians do is apply what is learned into the daily lives of the people we work with. That, friends, is what occupational therapy is about – helping people live full, rich lives doing what’s important to them.

Reyes, A. N., & Brown, C. A. (2016). Occupational therapists’ pain knowledge: A national survey. Disability and Rehabilitation: An International, Multidisciplinary Journal, 38(13), 1309-1317.

Rochman D, Herbert P. Rehabilitation professionals knowledge and attitudes regarding pain (COBS). Accessed 18 March 2015. Available from: http://prc.coh.org/html/rehab_professionals.htm.

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Do pain management programmes really influence “doing” in daily life?


Disability and coping are two of the most important targets in persistent pain management, along with distress and pain intensity (the latter perhaps being the most difficult to influence). A question, however, is whether existing measures of disability truly capture the activities or occupations that people most value. For example, if house cleaning is just not my thing, even if my functioning improved over the course of a programme, would I choose to spend that new capability on vacuum-cleaning or out there in the garden?!

The Westhaven-Yale Multidimensional Pain Inventory (MPI)(Kerns, Turk & Rudy, 1985)  is a true workhorse of pain management measurement: It’s a measure that provides, via the subscales, an estimate of the complex inter-relationships involved in pain-related disability and distress. Three profiles of coping approach have been derived from the MPI indicating “Adaptive Coping” – the person is likely to continue to improve and engage in living well if they carry on as they are; “Interpersonally Distressed” – the person is experiencing difficulties with relationships and is feeling unsupported by others around them; and “Dysfunctional” – the person is struggling with their pain, and both disability and distress can feel overwhelming.

But the disability components of the MPI don’t really indicate the kinds of activities that people might be passionate about – or those that are relevant to their lives. The items are about general activities people “typically” do – in a North American setting. I know they’ve been validated in many different populations but they still represent a general idea of activity and function rather than the unique and idiosyncratic occupations that people do. (What's the difference? An occupation is the unique way I perform the important tasks of my day - the way I dash around the house while simultaneously cleaning my teeth, getting the dogs outside, making sure the curtains are opened and the appliances off just before I head out the door! We could call this "getting ready for work" but the way I do it, and the way you do it is probably very different!)

Why is that important? Well, because people value different occupations differently, and because values drive motivation, a broad measure of disability may not capture the true value of a pain management programme. And this is why the Canadian Occupational Performance Measure (COPM) (Law, Baptiste, McColl, Opzoomer, Polatajko & Pollock, 1990) is often used by occupational therapists to establish exactly what it is a person wants to be able to do. Goal Attainment Scaling is another option.

The study

In this study by Persson, Eklund, Lexell & Rivano-Fischer (2017), the aims were to assess longterm changes in MPI profiles over the course of a year; to look at associations between “Adaptive Coper” profiles at follow-up and improvements in occupational performance; and to look at factors at baseline that might be used to predict changes over time. Participants were, as usual, attending a tertiary pain management centre at a University hospital. They took part in a 21 day programme (oh the luxury of time!), and were seen by a team working together (oh the luxury of a co-located team!) including a psychologist, physician, physiotherapist, occupational therapist and social worker (oh for interprofessional teamwork!). The measures taken at pre and post were the MPI, COPM, and background demographic details.

Now here’s where the analysis gets pretty technical: dropout rates and pre-treatment differences amongst the MPI profiles were analysed using Matt-Whitney U, Kruskal-Wallis, chi-squared and independent t-test. Cross-tabs were used to describe the distribution of the MPI profiles. McNemar’s test was used to assess changes over time on each of the four profiles, and ultimately the participants were grouped into four profiles: never AC (Adaptive coper); losing AC; gaining AC, and stable AC, and these groupings were used to analyse associations between changes in MPI profile and changes on COPM from baseline to follow-up. And this, folks, is why occupational therapists NEED to learn statistical analyses! Because they went on to use univariate and multivariate logistic regressions to see whether demographic factors would predict these profiles at follow-up, incorporating satisfaction and performance scores on COPM.

What did they find?

More participants started the programme with a profile of dsyfunctional or interpersonally distressed than adaptive coper – and at both discharge and follow-up the adaptive coping group increased to be the largest subgroup. 20% of the participants ended up in the “gaining AC” group, 11% the “stable AC” group, 6% formed the “losing AC” group, and 63% were never in the adaptive coping group at all. Not so terrific in terms of broad outcome measures, but pretty consistent with other programmes around the world.

On the more individualised outcome measure of the COPM, people in the never AC group showed least clinically relevant improvement, both the stable AC and gaining AC groups showed more improvement on occupational performance and satisfaction with performance than the never AC group, while the stable AC group improved more than the losing AC group in terms of occupational performance changes.

Long-term changes showed those who started as AC were more likely to stay that way over time, and baseline scores for occupational performance were significantly associated with being AC at follow-up – in other words, people who felt OK about what they could do in terms of occupation, tended to become more capable and less disabled over time as measured by the MPI. More importantly, those people who had higher baseline scores on occupational satisfaction were 1.3 times more likely to shift to the AC group over time. “Clinically relevant improvements on performance and satisfaction with performance at 1-year follow-up, in occupations prioritized by the participants, were associated with having an AC profile at follow-up.” (p. 6).

Confidence in doing important occupations breeds confidence in other parts of living with persistent pain.

What does this all mean anyway?

Well, importantly, people who shifted from one of the other profiles to adaptive coping over a year showed clinically relevant improvements in occupational performance and satisfaction with performance – the authors suggest these findings show improvements on and satisfaction with “doing and performing” important occupations. Not being classified into adaptive coping at any time was associated with least improvement in occupational performance and satisfaction. There is an association between “doing/performing” and “coping/adapting” that hasn’t really been studied. Perhaps starting with things people enjoy instead of beating them over the head with things they’ve never been interested in could improve pain management outcomes. Pain management programmes DO influence doing in real life – if real life doing is used as therapy!

The authors also point out that “30–47% of participants who did not show an AC profile at follow-up still showed clinically relevant improvements on occupational performance and on
satisfaction with occupational performance.” (p. 8) This suggests that the MPI coping profiles only represent one part of the outcomes that are important to individuals: occupation being the individualised daily doings that people value very highly, and pointing to the need to explore individualised outcome measurement in more studies. Given that patient-centred pain management is based on individual goals, using only generic measures is likely to give misleading outcomes about treatment efficacy.

 

Kerns IVRD,TurkDC, Rudy TE. (1985) West Haven-Yale Multidimensional Pain Inventory (WHYMPI). Pain. 23:345–56

Law M, Baptiste S, McColl M, Opzoomer A, Polatajko H, Pollock N. (1990). The Canadian Occupational Performance Measure: an outcome measure for occupational therapy. Canadian Journal of Occupational Therapy. 57(2), pp82–7.

Persson, E., Eklund, M., Lexell, J., & Rivano-Fischer, M. (2017). Psychosocial coping profiles after pain rehabilitation: Associations with occupational performance and patient characteristics. Disability and Rehabilitation: An International, Multidisciplinary Journal, 39(3), 251-260.

Thinking the worst – and willingness to do things despite pain


Catastrophising, perhaps more than any other psychological construct, has received pretty negative press from people living with pain. It’s a construct that represents a tendency to “think the worst” when experiencing pain, and I can understand why people who are in the middle of a strong pain bout might reject any idea that their minds might be playing tricks on them. It’s hard to stand back from the immediacy of “OMG that really HURTS” especially when, habitually, many people who have pain try so hard to pretend that “yes everything is really all right”. At the same time, the evidence base for the contribution that habitually “thinking the worst” has on actually increasing the report of pain intensity, increasing difficulty coping, making it harder to access effective ways around the pain, and on the impact pain has on doing important things in life is strong (Quartana, Campbell & Edwards, 2009).

What then, could counter this tendency to feel like a possum in the headlights in the face of strong pain? In the study I’m discussing today, willingness to experience pain without trying to avoid or control that experience, aka “acceptance”, is examined, along with catastrophising and measures of disability. Craner, Sperry, Koball, Morrison and Gilliam (2017) recruited 249 adults who were seeking treatment at an interdisciplinary pain rehabilitation programme (at tertiary level), and examined a range of important variables pre and post treatment.  Participants in the programme were on average 50 years old, mainly married, and white (not a term we’d ever use in New Zealand!). They’d had pain for an average of 10.5 years, and slightly less than half were using opioids at the time of entry to the programme.

Occupational therapists administered the Canadian Occupational Performance Measure, an occupational therapist-administered, semi-structured interview designed to assess a person’s performance and satisfaction with their daily activities (Law, Baptiste, McColl, Opzoomer, Polatajko & Pollock, 1990). The performance scale was used in this study, along with the Chronic Pain Acceptance Questionnaire (one of my favourites – McCracken, Vowles & Eccelston, 2004); the Pain Catastrophising Scale (Sullivan, Bishop & Pivik, 1995), The Patient Health Questionnaire-9 (Kroenke, Spitzer & Williams, 2001); and The Westhaven-Yale Multidimensional Pain Inventory (Kerns, Turk & Rudy, 1985).

Now here’s where the fun begins, because there is some serious statistical analysis going on! Hierarchical multiple regression analyses is not for the faint-hearted – read the info about this approach by clicking the link. Essentially, it is a way to show if variables of your interest explain a statistically significant amount of variance in your Dependent Variable (DV) after accounting for all other variables. Or, in this study, what is the relationship between pain catastrophising, acceptance and pain severity – while controlling for age, gender, opioids use, and pain duration. The final step was to enter a calculation of the interaction between catastrophising and acceptance, and to enter this into the equation as the final step. A significant interaction suggests one of these two moderates the other – and this is ultimately captured by testing the slopes of the graphs. Complex? Yes – but a good way to analyse these complex relationships.

Results

Unsurprisingly, pain catastrophising and acceptance do correlate – negatively. What this means is that the more a person thinks the worst about their pain, the less willing they are to do things that will increase their pain, or to do things while their pain is elevated. Makes sense, on the surface, but wait there’s more!

Pain catastrophizing was significantly (ps < .01) and positively correlated with greater perceived pain intensity, pain interference, distress due to pain, and depression – and negatively correlated with occupational therapist-rated functioning. Further analysis found that only pain catastrophising (not acceptance) was associated with pain severity, while both catastrophising and acceptance predicted negative effect (mood) using the WHYMPI, but when the analysis used the PHQ-9, both pain catastrophising and pain acceptance uniquely predicted depressive symptoms.  When pain interference was used as the dependent variable, pain acceptance uniquely predicted the amount of interference participants experienced, rather than catastrophising. The final analysis was using the performance subscale of the COPM, finding that pain acceptance was a predictor, while catastrophising was not.

What does all this actually mean?

Firstly, I found it interesting that values weren’t used as part of this investigation, because when people do daily activities, they do those they place value on, for some reason. For example, if we value other people’s opinions, we’re likely to dress up a bit, do the housework and maybe bake something if we have people come to visit. This study didn’t incorporate contexts of activity – the why question. I think that’s a limitation, however, examining values is not super easy, however it’s worth keeping this limitation in mind when thinking about the results.

The results suggest that when someone is willing to do something even if it increases pain, or while pain is elevated, this has an effect on their performance, disability, the interference they experience from pain, and their mood.

The results also suggest that catastrophising, while an important predictor of pain-related outcomes, is moderated by acceptance.

My question now is – what helps someone to be willing to do things even when their pain is high? if we analyse the CPAQ items, we find things like “I am getting on with the business of living no matter what my level of pain is.”;  “It’s not necessary for me to control my pain in order to handle my life well.”; and “My life is going well, even though I have chronic pain.”. These are important areas for clinicians to address during treatment. They’re about life – rather than pain. They’re about what makes life worth living. They’re about who are you, what does your life stand for, what makes you YOU, and what can you do despite pain. And these are important aspects of pain treatment: given none of us can claim a 100% success rate for pain reduction. Life is more than the absence of pain.

 

 

Craner, J. R., Sperry, J. A., Koball, A. M., Morrison, E. J., & Gilliam, W. P. (2017). Unique contributions of acceptance and catastrophizing on chronic pain adaptation. International Journal of Behavioral Medicine, 24(4), 542-551.

Kerns IVRD,TurkDC, Rudy TE. (1985) West Haven-Yale Multidimensional Pain Inventory (WHYMPI). Pain. 23:345–56.

Kroenke K, Spitzer RL, Williams JB. The PHQ-9: validity of a brief depression severity measure. Journal of General Internal Medicine. 16(9), 606-13.

Law M, Baptiste S, McColl M, Opzoomer A, Polatajko H, Pollock N. (1990). The Canadian Occupational Performance Measure: an outcome measure for occupational therapy. Canadian Journal of Occupational Therapy. 57(2), pp82–7.

McCracken LM, Vowles KE, Eccleston C. (2004). Acceptance of chronic pain: component analysis and a revised assessment method. Pain. 107(1–2), pp159–66.

Quartana PJ, Campbell CM, Edwards RR. (2009) Pain catastrophizing: a critical review. Expert Reviews in Neurotherapy, 9, pp 745–58.

SullivanMLJ, Bishop SR, Pivik J. (1995). The Pain Catastrophizing Scale: development and validation. Psychological Assessment. 7:524–32.

Using more than exercise for pain management


In the excitement and enthusiasm for exercise as a treatment for persistent pain, I wonder sometimes whether we’ve forgotten that “doing exercise” is a reasonably modern phenomenon. In fact, it’s something we’ve really only adopted since our lifestyle has moved from a fairly physically demanding one, to one more sedentary (Park, 1994). I also wonder if we’ve forgotten that exercise is intended to promote health – so we can do the things we really want or need to do. Remembering, of course, that some people find exercise actually exacerbates their pain (Lima, Abner & Sluka, 2017), and that many folks experience pain as an integral part of their exercise (think boxing, marathon running, even going to a gym – think of the pain of seeing That Much Lycra & Sweat).

While it’s become “exercise as medicine” in modern parlance (Pedersen & Saltin, 2015; Sallis, 2009; Sperling, Sadnesara, Kim & White, 2017), I wonder what would happen if we unpacked “exercise” and investigated what it is about exercise that makes it effective by comparison with, say, activities/occupations that incorporate whole body movement?

One of the factors that’s often omitted when investigating coping strategies or treatments, especially lifestyle/self management ones, is the context and meaning people give to the activity. Context is about the when, where and how, while meaning is the why. Whether the positives (meaning, and values people place on it) outweigh the negatives (let’s face it, the lycra and sweat and huffing and puffing does not inherently appeal) are factors that enhance (or not) adherence to exercise and activity. One positive is a sense of flow, or “an optimal subjective psychological state in which people are so involved in the activity that nothing else seems to matter; the experience itself is so enjoyable that people will do it even at great cost, for the sheer sake of doing it”(Csikzentmihalyi, 1990, p. 4). I can think of a few things I lose myself in – reading a good book; fishing; paddling across a lake; photography; silversmithing; gardening…

Robinson, Kennedy & Harmon (2012) examined the experiences of flow and the relationship between flow and pain intensity in a group of people living with persistent pain. Their aim was to establish whether flow was an “optimal” experience of people with chronic pain. Now the methodology they used was particularly interesting (because I am a nerd and because this is one technique for understanding daily lived experiences and the relationships between variables over time). They used electronic momentary assessment (also known as ecological momentary assessment) where participants were randomly signaled seven times a day for one week to respond to a question about flow. Computationally challenging (because 1447 measurement moments were taken – that’s a lot of data!), although not using linear hierarchical modeling (sigh), they analysed one-way between group analyses of variance (ANOVA) to explore differences in pain, concentration, self-esteem, motivation, positive affect and potency across four named states “flow, apathy, relaxation and anxiety”. We could argue about both the pre-determined states, and the analysis, but let’s begin by looking at their findings.

What did they find?

People in this study were 30 individuals with persistent pain attending a chronic pain clinic. Their ages ranged from 21 – 77 years, but mean age was 51, and there were 20 women and 10 men (remember that proportion). People had a range of pain problems, and their pain had been present for on average 68 months.

The contexts (environments) in which people were monitored were at home, or “elsewhere”, and, unsurprisingly, 71% were at home when they were asked to respond. Activities were divided into self-care, work and leisure (slightly less time in work than in leisure or self care respectively).  The purpose of the activities were necessity (35%), desire (40%), or “nothing else to do” (18%). And most people were doing these things with either alone or with family, with very small percentages with friends, colleagues or the general public.

Now we’d expect that people doing things they feel so wrapped up in that nothing else matters should experience lower pain – but no, although this was hypothesised, pain intensity scores during flow trended lower – but didn’t actually reach significance. When we add the findings that concentration, self-esteem, motivation, and potency mean scores were highest in the flow state and mean scores were lowest in the apathy and anxiety states, we can begin to wonder whether engaging in absorbing activities has a major effect on pain intensity – or whether the value placed on doing the activities is actually the most important feature for people with pain. Interestingly, people felt their flow experiences while outside the home: this happened rather less often than being in the home, where apathy was most present. So… doing something absorbing is more likely to occur away from home, while remaining at home is associated with more apathy and perhaps boredom. Finally, flow occurred in work settings more than elsewhere, suggesting yet again that work is a really important feature in the lives of all people, including people living with pain. Of course that depends on the kind of work people are doing…and the authors of this paper indicate that people with persistent pain in this study have few places in which they can do highly engaging activities, even including work.

What does this mean for exercise prescription?

Engaging people in something that holds little meaning, has little challenge and may not be in the slightest bit enjoyable is probably the best way to lose friends and have clients who are “noncompliant”. I think this study suggests that activities that provide challenge, stimulation, movement possibilities, the opportunity to demonstrate and develop skill – and that people find intrinsically lead to flow – might be another way to embrace the “movement is medicine” mantra. I wonder what would happen if we abolished “exercises” and thought about “movement opportunities”, and especially movement opportunities in which people living with pain might experience flow? I, for one, would love to see occupational therapists begin to examine flow experiences for people living with pain and embraced the creativity these experiences offer for the profession.

 

 

Csikszentmihalyi, M. (1990). Flow: The psychology of optimal experience. New York: Harper Collins.

Lima, L. V., Abner, T. S., & Sluka, K. A. (2017). Does exercise increase or decrease pain? Central mechanisms underlying these two phenomena. The Journal of physiology, 595(13), 4141-4150.

Park, R. (1994). A Decade of the Body: Researching and Writing About The History of Health, Fitness, Exercise and Sport, 1983-1993. Journal of Sport History, 21(1), 59-82. Retrieved from http://www.jstor.org/stable/43610596

Pedersen, B. K., & Saltin, B. (2015). Exercise as medicine–evidence for prescribing exercise as therapy in 26 different chronic diseases. Scandinavian journal of medicine & science in sports, 25(S3), 1-72.

Robinson, K., Kennedy, N., & Harmon, D. (2012). The flow experiences of people with chronic pain. OTJR: Occupation, Participation and Health, 32(3), 104-112.

Sallis, R. E. (2009). Exercise is medicine and physicians need to prescribe it!. British journal of sports medicine, 43(1), 3-4.

Sperling, L. S., Sandesara, P. B., Kim, J. H., & White, P. D. (2017). Exercise Is Medicine. JACC: Cardiovascular Imaging, 10(12).

One way of using a biopsychosocial framework in pain management – vi


I could write about a BPS (biopsychosocial) model in every single post, but it’s time for me to explore other things happening in the pain management world, so this is my last post in this series for a while. But it’s a doozy! And thanks to Eric Bowman for sharing an incredibly relevant paper just in time for this post…

One of the problems in pain management is that there are so many assessments carried out by the professionals seeing a person – but very little discussed about pulling this information together to create an overall picture of the person we’re seeing. And it’s this aspect I want to look at today.

My view is that a BPS approach provides us with an orientation towards the multiple factors involved in why this person is presenting in this way at this time (and what is maintaining their presentation), and by integrating the factors involved, we’re able to establish a way to reduce both distress and disability. A BPS approach is like a large-scale framework, and then, based on scientific studies that postulate mechanisms thought to be involved, a clinician or team can generate some useful hypotheses through abductive reasoning, begin testing these – and then arrive at a plausible set of explanations for the person’s situation. By doing so, multiple different options for treatment can be integrated so the person can begin to find their way out of the complex mess that pain and disability can bring.

The “mechanisms” involved range from the biological (yes, all that cellular, genetic, biomechanical, muscle/nerve/brain research that some people think is omitted from a BPS approach IS included!), to the psychological (all the attention, emotion, behavioural, cognitive material that has possibly become the hallmark of a BPS approach), and eventually, to the social (interactions with family, friends, community, healthcare, people in the workplace, the way legislation is written, insurers, cultural factors and so on). That’s one mess of stuff to evaluate!

We do have a framework already for a BPS approach: the ICF (or International Classification of Functioning, Disability and Health) provides one way of viewing what’s going on, although I can empathise with those who argue that it doesn’t provide a way to integrate these domains. I think that’s OK because, in pain and disability at least, we have research into each one of these domains although the social is still the most under-developed.

Tousignant-Laflamme, Martel, Joshi & Cook (2017) provide an approach to help structure the initial domains to explore – and a way to direct where attention needs to be paid to address both pain and disability.

What I like about this model (and I urge you to read the whole paper, please!) is that it triages the level of complexity and therefore the intervention needed without dividing the problem into “physical” and “psychosocial”. This is important because any contributing factor could be The One to most strongly influence outcome – and often an integrated approach is needed, rather than thinking “oh but the biological needs to be addressed separately”.

Another feature I like about this model is the attention paid to both pain and disability.

Beginning from the centre, each of the items in the area “A” is something that is either pretty common, and/or easily modified. So, for example, someone with low back pain that’s eased by flexion, maybe has some osteoarthritis, is feeling a bit demoralised and worries the pain is going to continue, has a job that’s not readily modified (and they’re not keen on returning) might need a physiotherapist to help work through movement patterns, some good information about pain to allay their worries, an occupational therapist to help with returning to work and sleeping, and maybe some medication if it helps.

If that same person has progressed to become quite slow to move and deconditioned, they’re experiencing allodynia and hyperalgesia, they have a history of migraine and irritable bowel, their sleep is pretty rotten, and they’re avoiding movements that “might” hurt – and their employer is pretty unhappy about them returning to work – then they may need a much more assertive approach, perhaps an intensive pain management programme, a review by a psychiatrist or psychologist, and probably some occupational therapy intervention at work plus a graded exposure to activities so they gain confidence despite pain persisting. Maybe they need medications to quieten the nervous system, perhaps some help with family relationships, and definitely the whole team must be on board with the same model of healthcare.

Some aspects are, I think, missing from this model. I’d like to see more attention paid to family and friends, social and leisure activities, and the person’s own values – because we know that values can be used to help a person be more willing to engage in things that are challenging. And I think the model is entirely deficits-based meaning the strengths a person brings to his or her situation aren’t incorporated.  Of course, too, this model hasn’t been tested in practice – and there are lots of gaps in terms of the measures that can be used to assess each of these domains. But as a heuristic or a template, this model seems to be practical, relatively simple to understand – and might stop us continuing to sub-type back pain on the basis of either psychosocial risk factors or not.

Clinicians pondering this model might now be wondering how to assess each of these domains – the paper provides some useful ideas, and if the framework gains traction, I think many others will add their tuppence-worth to it. I’m curious now to see how people who experience low back pain might view an assessment and management plan based on this: would it be acceptable? Does it help explain some of the difficulties people face? Would it be useful to people living with pain so they can explore the factors that are getting in the way of recovery?

Tousignant-Laflamme, Y., Martel, M. O., Joshi, A. B., & Cook, C. E. (2017). Rehabilitation management of low back pain – it’s time to pull it all together! Journal of Pain Research, 10, 2373-2385. doi:10.2147/JPR.S146485

One way of using a biopsychosocial framework in pain management – iv


And yes! There’s more to this series of posts on how I use a biopsychosocial model in practice!

Today’s post is about moving from a conceptual model to a practical model, or how we can use research in our clinical reasoning.

A biopsychosocial model (BPSM) as envisaged by Engel was a framework for clinicians to think about why this person is presenting in this way at this time (and what may be maintaining their situation), as well as what could be done to reduce distress and disability. Engel wanted clinicians to go beyond disease processes, isolated from the people experiencing them, and to explore aspects of how the person coped with everyday challenges (including health), the factors that influenced their decision that their health problem was indeed a problem, and the context of seeking healthcare.  He wanted clinicians to be scientific about how they generated hypotheses which could then be tested in clinical practice, and ultimately confirm or disconfirm the contribution of that factor.

The “bio” aspect of pain (which is a contentious word – I’ll comment in a bit) involves disease processes, trauma, all the biological aspects prior to conscious awareness of the “ouch” we know as pain. Theoretical developments in this area include all the work being conducted in terms of understanding anatomy and physiology of the human body, from molecular study (information transmission from one neurone to another); detailed understanding of spinal cord mechanisms; of the role of glia; of inflammatory processes; of genetic and epigenetic changes; of relationships between blood flow to and from various parts of the brain; of biomechanics; of normal healing processes – and so on. There’s no lack of information being generated by researchers undertaking basic science about the biological mechanisms involved in our experience of pain. Because I typically see people with persistent pain that has been present for maybe 12 months or more (usually much longer than that), I rely on the work of my colleagues to make a good diagnosis. Most people have had more investigation than is probably helpful for them, and I think we can use Clifford Woolf’s broad mechanisms as a reasonable stance when considering an underlying mechanism involved in a person’s pain. Essentially he identifies four main mechanisms: nociceptive, inflammatory, neuropathic and what is now known as “nociplastic” (where the nociceptive system appears to have a problem with processing information).

Yes, we can argue that our current state of understanding is incomplete and there is more to learn, but by working from these basic mechanisms I think we can begin to work on the “bio” part of a biopsychosocial model with a degree of confidence. For my work, anyway, these mechanisms seem to provide a reasonable framework from which the “bio” part of management can begin.

But this is where many clinicians start – and stop. Directly treating, for example, inflammation, certainly provides a reduction in pain – for example, my partner who takes Humera for his ankylosing spondylitis. He no longer experiences inflammatory pain and as his CRP levels reduced, so too did his pain. We can see similar effects when someone has a grotty old hip joint replaced, which removes nociceptive input, ultimately leaving them with a shiny new and painfree hip (in most cases). But as my partner found out, having no pain doesn’t immediately change old habits.

His situation is a nice illustration of the interaction between a disease process which responded really well to a drug that eliminates inflammation, and his beliefs and behaviour which wasn’t changed. Let me explain – once his drug kicked in and he had no pain, he found it odd not to have to think about his pain when climbing hills. It took him about a month or two to fully return to hill climbing in the way he’d done before his anky spond started. That’s right – no pain for a month or two, but that long before he felt confident to go about his activities. And he’s not a man who worries much about his pain!

To add some theory to this, his beliefs (that if he climbed hills a full speed he would inevitably end up with a very sore back) led to him having learned not to go a full pace (through both classical and operant conditioning). We could call this “pain-related fear and avoidance” – or “fear avoidance”. This is one theory that has been extensively researched, and we can integrate the hypotheses generated from this theory into our understanding of why my partner initially had some hesitation about climbing hills. Flowing on from this, we can consider treatments that have been found useful to address his hesitation.

The first treatment could be “explaining pain” to him. Now that wasn’t useful in this case because – oh yeah – his pain had gone! And although he knew his inflammatory pain wasn’t going to harm him (otherwise he’d never have been a high country fire fighter for 20 years despite his anky spond!), he didn’t like the after-effects of aggravating his pain. What helped was addressing his anxiety about the potential for a big flare-up – and this was primarily about beginning at a level that was just beyond his “normal” hill climb, and gradually progressing.

This superficially looks like “exercise” – but it’s exercise with a twist. My partner is as fit as a buck rat. His cardiovascular fitness was fine. Gradually increasing his hill walking wasn’t about increasing fitness – it was about helping him approach an activity that he was a tad concerned might flare his pain up, leading to a rotten night’s sleep (as it had in the past). In fact, this “treatment” was almost all about reducing avoidance by exposing him to things that increased his anxiety just a bit – enough for him to establish that the rotten sleep consequence didn’t happen.

So a biopsychosocial approach to his recovery involved the biological which quickly resolved his pain but left him with some concerns (reasonable ones I think) about pushing himself too hard. Addressing those concerns by taking a theory developed originally from phobia research, applying it to his situation and developing a treatment based on this theory, has led to his return to full participation. Using research-based information to address another part of “why is this person presenting in this way at this time, and what might be maintaining this situation” involves thinking beyond the disease process, and into understanding the problems the person identifies. It means thinking beyond a single discipline. It means reading widely and thinking creatively. That was a good part of Engel’s original proposition.

 

One way of using a biopsychosocial framework in pain management – ii


Last week I discussed case formulation as one way of using a biopsychosocial framework in pain management, and I reviewed Benedetti’s description of the process of becoming aware that something’s wrong, seeking relief from that discomfort, then the “meet the therapist moment”, and finally the “receiving the therapy” steps along the way. Benedetti considers this within a neurobiological model (Benedetti, 2013), while Engel (1977) used general systems theory to frame his critique of the original biomedical model.

This week I want to look at a behavioural model. I do this partly because I think it’s been a long time since this model was brought into our discussions about pain and pain behaviour, and I do it because I think we can understand a great deal about why different people respond differently to their pain when we look at behaviour alone – before we even begin to look at beliefs or attitudes about pain.

Let’s do a little revision (Psych 101). In a behavioural model, we’re looking at two main forms of conditioning: Pavlovian or classical conditioning, and operant or instrumental conditioning. In the case of pain, we also need to revisit the distinction made between the experience (pain), and our behavioural response to that experience (pain behaviours). Pain behaviours are typically filtered or influenced by what we think is going on (judgements about the meaning of pain – eg super-scary crumbling back, or I just did too much gardening), what we’ve learned to do, and the context in which we’re experiencing pain. That context can be current (eg I’m in Church and it’s very quiet so I’d better not swear as I hit my toe against the pew!), or past (eg last time I kicked my toe against the pew and swore, everyone looked at me – how embarrassing!), or even future (eg if I swear when I kick my toe against the pew, I’ll never be able to show my face here again!). It’s the learned part I want to discuss today.

Pain behaviours range from reflex withdrawal responses (lifting the foot up while straightening the other leg to support me when I stand on a tack), to quite complex behaviours we’ve learned are relevant in our environment (filling out a claim form for compensation and treatment).

We probably developed pain behaviours as part of our evolutionary development: the reflex withdrawal behaviours don’t require conscious thought, so they begin in infancy (actually, before), and rely on spinal mechanisms (eg Rohrbach, Zeiter, Andersen, Wieling & Spadavecchia, 2014), with various parts of the brain becoming involved as part of strategies to avoid threat (see Damasio and Damasio (2016) for some insights into evolutionary aspects of withdrawal reflex). But because we have a developed cortex, we’ve learned ways of suppressing our responses, depending on social context – and on responses from others around us.

Reflexive responses are those associated with classical conditioning – and lead us to learn relationships between previously non-threatening stimuli and both withdrawal responses and the physiological arousal that goes with them. For example, if I bend over to make the bed and OUCH! my back suddenly gets really sore. I straighten up very carefully – and I’ve learned something: next time I bend over to make the bed, I’ll be remembering and preparing for that OUCH! to happen once again. The bed and bending forward movement become associated, in my mind, with that OUCH! Of course, for most of us, once we make the bed a few more times (make that many times), we’ll learn that OUCH! doesn’t inevitably follow the bend, so we gain confidence to repeat that movement without preparing for the OUCH! Now what do you think might happen if I never had an opportunity to make the bed again? Say, if I have a really protective person in my life who stopped me every time I go to do it – will that association I have in my mind persist, or will it reduce? This is, in essence, what is thought to happen when someone develops so-called “fear avoidance”. Note: the experience of pain does not have to re-occur for me to avoid bending and begin to rev my nervous system up. What needs to happen is for the first instance to be pretty strong, and for me to not test my belief again. It’s the behaviour that persists (avoidance) because by avoiding something I believe will be OUCH! I avoid experiencing OUCH! And by avoiding that experience, I never test whether OUCH! happens every time, or just that once.

Let’s look at the other really powerful learning mechanism: operant conditioning. In this situation, the likelihood of me repeating my behaviour is increased or reduced, depending on responses in the environment. So, let’s take my bending forward and experiencing OUCH! If my partner (bless him) then decided to fuss over me, make me a cup of tea and tell me not to worry about making the bed ever again – AND if I liked that idea – my response is likely to be to avoid making the bed. I might even go as far as wincing a bit when walking, so he makes me another cup of tea and fusses over me. I might talk about my back pain because he’s so concerned about me (or I really want him to be concerned about me) and if he carries on fussing, I’m likely to carry on with these behaviours. Now picture that in a two-year-old kid – every time the kid trips and cries, some concerned parent comes picks him up, something the kid likes, it’s probable that kid will learn that this is normal, and something to do when he hurts. For more on learning theory, Johan Vlaeyen summarises the state of play in a review paper from 2015 (Vlaeyen, 2015).

We’re smart, us humans. We learn to predict and remember patterns even from imprecise data – it doesn’t take much for us to put two and two together, particularly when it’s something relevant to surviving! Whenever I’m listening to someone telling me their story about why they’re presenting in this way at this time, and what is maintaining their situation, I keep thinking about the various learning mechanisms involved. Social context and the people around us and how they respond to us exert a powerful force on what we do – and many times we’re not even aware of why we do what we do.  Knowing this stuff means that when I’m listening to someone’s story I try very hard to factor in those things that may have influenced what the person does, rather than just thinking the person is aware of doing all they are doing.

 

Benedetti, F. (2013). Placebo and the new physiology of the doctor-patient relationship. Physiological Reviews, 93(3), 1207-1246. doi:10.1152/physrev.00043.2012

Damasio, A., & Damasio, H. (2016). Pain and other feelings in humans and animals. Animal Sentience: An Interdisciplinary Journal on Animal Feeling, 1(3), 33.

Engel, G. L. (1977). The need for a new medical model: A challenge for biomedicine. Science, 196(4286), 129-136.

Rohrbach, H., Zeiter, S., Andersen, O. K., Wieling, R., & Spadavecchia, C. (2014). Quantitative assessment of the nociceptive withdrawal reflex in healthy, non-medicated experimental sheep. Physiology & behavior, 129, 181-185.
Vlaeyen, J. W. (2015). Learning to predict and control harmful events: Chronic pain and conditioning. Pain, 156, S86-S93.

Minding your body: Interoceptive awareness, mindfulness and living well


We all grow up with a pretty good idea of what our body feels like; what normal is. It’s one of the first “tasks” of infancy, it seems, to work out what is me and what is not. When people experience a disturbance to the way their body moves or feels, it can take some time to get used to that new way of being. In pregnancy, where the body takes on a different shape and dimension, it’s not uncommon to bump into things because the new shape hasn’t yet sunk in!

This awareness of “what my body feels like” is called interoceptive awareness (IA), and I was intrigued to read this paper by Hanley, Mehling and Garland (2017) in which IA is examined in relation to dispositional mindfulness (DM). DM is thought to be the innate tendency to notice without judging or automatically reacting to what is going on. IA may be extremely sensitive in some people – for example, people with health anxiety might notice their sweaty palms and heart palpitations and then worry that they’re about to have a heart attack, or the same symptoms in someone with social anxiety might be experienced as indications to LEAVE RIGHT NOW because EVERYONE is looking at ME.

I’m not sure of research into IA in people with persistent pain, although I am positive it’s something that has been studied (see Mehling, Daubenmier, Price, Acree, Bartmess & Stewart, 2013). As a result, in my conclusions I’m going to draw from my experience working with those living with persistent pain, and extrapolate wildly!

This study aimed to establish the relationship between various items on two questionnaires used to measure IA and DM: the MAIA (Multidimensional Assessment of Interoceptive Awareness), and the FFMQ (Five Facet Mindfulness Questionnaire). The paper itself discusses the first measure as empirically derived and confirmed by focus groups, and having associations with less trait anxiety, emotional susceptibility and depression – in other words, high scores on this measure (awareness of body sensations and judging those sensations) are associated with important factors influencing our wellbeing. The second measure is described as “one of the most commonly used self-report measures of DM”. It consists of five scales thought to measure important aspects of mindfulness (observing, not reacting and acting with awareness).

Along with these two measures, the authors examined wellbeing, which essentially was defined as a tendency to accept oneself, have a purpose, manage the environment, develop good relationships, continue to grow as a person and be independent and autonomous. We could probably argue about these dimensions in view of what may be a cultural component (autonomy may not be highly favoured in some communities).

Recruitment was via mTurk, Amazon’s crowdsourcing website. As a result participants possibly don’t represent the kinds of people I would see in clinical practice. And half of the 478 participants were excluded because people didn’t complete all the questionnaires. I could quibble about this sample, so bear that in mind when you consider the results.

Results

Turning to the results, the first finding was a good correlation between all three questionnaires, with the FFMQ more strongly correlated with psychological wellbeing than the MAIA. But these researchers wanted more! So they carried out canonical correlation analysis, which is used to correlate the latent variables present in measurement instruments. It’s complicated, but what it can tell us is how underlying aspects of two unrelated measures might fit together. In this instance, the researchers found that two of the FFMQ (non-reacting and observing) were related to six of the eight MAIA factors (attention regulation, self-regulation, trusting, emotional awareness, body listening and noticing). They also found that FFMQ ‘non-judging’ and ‘acting with awareness’ were associated with MAIA ‘not worrying’ subscale.

What does this tell us? Well, to me it’s about grouping somewhat-related items together from two instruments to work out their contribution to something else. The authors thought so too, and therefore completed a further analysis (told you it was complicated!), to look at a two-step hierarchical multiple regression where the two sets of scales were entered into equations to see how much each contributed to the psychological wellbeing score. Whew!

What they found was interesting, and why I’m fascinated by this study despite its shortcomings.

What can we do with this info?

Being mindfully observant and non-reactive seems to be associated with a person’s ability to notice and control attention to what’s going on in the body. Makes sense to me – knowing what goes on in your body but being able to flexibly decide how much to be bothered about, and what you’re going to do about those sensations will make a difference to how well you can cope with things like fatigue, hunger, the need to change body position or to sustain a position when you’re focusing on something else – like hunting!

Apparently, being able to attend to body sensations is also part of regulating your emotional state, and if you can do this, you’ll generally experience your body as a safe and “trustworthy” place. And if you can do this when your body doesn’t feel so good yet still remain calm and accepting, this is a good thing. In the final analysis, these authors called the first cluster of statements “Regulatory awareness” – being aware of your body and regulating how you respond to it. The second cluster related more with non-judging and acting with awareness, so the authors called this “Acceptance in action”.

For people living with persistent pain, where the body often does not feel trustworthy and there’s an increased need to “ignore” or “let go” or “not judge” painful areas, it seems that one of the most important skills to learn is how to self regulate responses to IA. To take the time to notice all the body (not ignore the sore bits, nor obsess about the sore bits). This doesn’t come easily because I think for most of us, we’ve learned we need to notice pain – after all, ordinarily it’s helpful! The second part is to accept in action – in other words discriminating between unpleasant body sensations are should be worried about, and those not needing our attention is an adaptive skill. Perhaps mindfulness gives us better capabilities to discriminate between what needs to be taken into account, and what does not.

Interestingly, the least strongly associated response items were related to using words to describe what goes on in the body. For me this suggests experiential practices might be more useful to help people develop these two skills than simply talking about it. And suggests that maybe we could use meditative movement practices as a good way to develop these skills.

R.A. Baer, G.T. Smith, J. Hopkins, J. Krietemeyer, L. Toney, (2006) Using self-report assessment methods to explore facets of mindfulness, Assessment 13 27–45.

Hanley, A. W., Mehling, W. E., & Garland, E. L. (2017). Holding the body in mind: Interoceptive awareness, dispositional mindfulness and psychological well-being. Journal of Psychosomatic Research, 99, 13-20. doi:https://doi.org/10.1016/j.jpsychores.2017.05.014

W.E. Mehling, J. Daubenmier, C.J. Price, M. Acree, E. Bartmess, A.L. Stewart, (2013). Self-reported interoceptive awareness in primary care patients with past or current low back pain, Journal of Pain Research. 6

W.E. Mehling, C. Price, J.J. Daubenmier, M. Acree, E. Bartmess, A. Stewart, (2012) The multidimensional assessment of interoceptive awareness (MAIA), PLoS One 7  e48230.

Back to basics about psychosocial factors and pain – v


I’ve been writing about psychosocial factors and pain but I realise that I haven’t actually defined what I mean by psychosocial factors. The strange thing about this term is that it’s often conflated with “psychological” or “psychopathological” when it’s actually not. So… where to begin?

The Collins English Dictionary defines psychosocial as: “of or relating to processes or factors that are both social and psychological in origin”, while the Oxford English Dictionary defines it as “Of or relating to the interrelation of social factors and individual thought and behaviour.” According to the Oxford, it first appeared in the American Journal of Psychology in 1890 when it was used to describe the factors associated with the increase of alcoholism. An 1899 journal used it to describe “… psycho-social phenomena, such as language, customs, rights, religion etc., arising from the action of social elements with or upon the individual mind.”

So, the term is fairly recent but seems to have always been associated with broader influences on thoughts and behaviour – that is, a reciprocal response between what individuals think and do, and what helps to shape (and also responds to) what happens in the community.

When we think about pain, the most common “psychosocial” factors seem to be psychological – things like attention (vigilance), catastrophising (thinking the worst), negative affect (low mood), treatment seeking (behaviours associated with looking for help), avoidance (not doing, not approaching). What is lacking in clinical practice, in my humble opinion, is the relationship between how these factors develop and are maintained, and how those around an individual (both family and the wider community) respond to these factors. It’s not that there is no research into these relationships – it’s that research is complex, it’s tough to conduct experiments in this field, and effecting change once relationships are identified is pretty hard. More than that, health professionals typically see individuals, not people-in-context.

BUT here are some of the areas currently being explored.

Clinician behaviour – there would be few readers of this blog who are unfamiliar with Ben Darlow’s work on the power of what clinicians say (Darlow, Dowell, Baxter, Mathieson, Perry & Dean, 2013), though he’s not the first research to begin to look at this – Tamar Pincus and others have also reviewed the influence of practitioners beliefs on what they do for people with persistent pain (Parsons, Harding, Breen, Foster, Pincus, Vogel & Underwood, 2007).  The broad conclusions from this body of work, of which these two are tiny tips of a very large iceberg, is that what clinicians believe about pain and chronicity and hurt/harm influences both their treatment recommendations and their attitude towards people experiencing persistent pain, and has a direct effect on chronicity in the acute stages of a pain problem.

Family responses – Herta Flor and colleagues explored the impact of persistent pain on family relationships way back in the 1980’s, while much more recently,  Burns, Post, Smith, Porter et al (in press) investigated the interaction between spouse criticism and the effect on pain intensity and behaviour in people with persistent low back pain. Chan, Connelly & Wallace (2017) established that poor peer relationships influenced both emotional functioning and persistent pain amongst adolescents, while treatment seeking amongst adolescents was found to be associated with elevated treatment seeking in their parents (Stone & Wilson, 2016). Whether the relationships are genetic (in family patterns of persistent pain and disability), or learned (social learning theory) or a mix of both – it looks like how others respond and behave in relation to pain and disability has a strong influence on persistent pain in an individual.

Work – This, naturally, has been the place of many a study trying to establish a relationship between biomechanical factors and the onset and maintenance of pain, but it has also been the location for studies examining social relationships like supervisory responses, peer relationships, employer flexibility along with the personal effects of workplace stress on the body. I’m not going to review the myriad studies, but point you to a good systematic review of prognostic factors for return to work by Steenstra, Munhall, Irvin, Oranye, Passmore et al (2016) to demonstrate just how many factors have already been identified.

I’ve barely touched the surface of the social aspects influencing our experience of pain and disability. It’s evident that these factors have been identified – but let me ask you this: How often do you identify and then provide an intervention for these social factors? And if not, why not? And if not you – who?

 

Burns, J. W., Post, K. M., Smith, D. A., Porter, L. S., Buvanendran, A., Fras, A. M., & Keefe, F. J. (2017). Spouse criticism and hostility during marital interaction: effects on pain intensity and behaviors among individuals with chronic low back pain. Pain.
Chan, S. F., Connelly, M., & Wallace, D. P. (2017). The Relationship Between Pain Characteristics, Peer Difficulties, and Emotional Functioning Among Adolescents Seeking Treatment for Chronic Pain: A Test of Mediational Models. Journal of Pediatric Psychology, jsx074.
Darlow, B., Dowell, A., Baxter, G. D., Mathieson, F., Perry, M., & Dean, S. (2013). The enduring impact of what clinicians say to people with low back pain. The Annals of Family Medicine, 11(6), 527-534.
Flor, H., Turk, D. C., & Scholz, O. B. (1987). Impact of chronic pain on the spouse: marital, emotional and physical consequences. Journal of psychosomatic research, 31(1), 63-71.
Parsons, S., Harding, G., Breen, A., Foster, N., Pincus, T., Vogel, S., & Underwood, M. (2007). The influence of patients’ and primary care practitioners’ beliefs and expectations about chronic musculoskeletal pain on the process of care: a systematic review of qualitative studies. The Clinical journal of pain, 23(1), 91-98.
Steenstra, I. A., Munhall, C., Irvin, E., Oranye, N., Passmore, S., Van Eerd, D., … & Hogg-Johnson, S. (2016). Systematic review of prognostic factors for return to work in workers with sub acute and chronic low back pain. Journal of occupational rehabilitation, 1-13.
Stone, A. L., & Wilson, A. C. (2016). Transmission of risk from parents with chronic pain to offspring: An integrative conceptual model. Pain, 157(12), 2628-2639.

Back to basics about psychosocial factors and pain – iii


Last week I discussed some of the areas in the brain, and basic principles, that are currently thought to influence our pain experience. This week I thought I’d introduce one of my favourite ways of considering pain mechanisms, mainly because it helps me think through the four main kinds of mechanisms, and can influence our treatment approach. At this stage I want to raise my hand to acknowledge the following:

  • My gratitude to Dr John Alchin, longtime friend and colleague, who first pointed this paper out to me and has shared it with hundreds of people who go to see him at the local tertiary pain management centre.
  • We know this is a simplified, under-developed approach to mechanisms underpinning pain, but it’s helpful nevertheless.
  • Most of our patients will have a combination of mechanisms involved in their experience, not just one.
  • This approach to mechanisms doesn’t include the psychological or social – just the primary biological processes.
  • Throughout this blog, when I use the word “pain” I mean the experience we have once whatever mechanisms involved filter up through to our awareness. So while I talk about peripheral mechanisms, they’re only experienced as pain once we become aware of them – and that process involves a whole lot of what I discussed in my last post .

Clifford Woolf wrote this paper in 2010, and although the research into mechanisms has continued unabated, I think it provides clinicians with a reasonable guide to considering how best to tackle treatment. He begins by dividing the mechanisms into “useful” and “useless” pain – ie pain that is useful for adaptation, survival, warning, alerts. Just as it’s possible to have dysfunction or disease of our cardiac, pulmonary, gastro-intestinal, and skeletal systems, I think it’s just as plausible that we can have something go wrong with our nociceptive system. In fact, because of its complexity, it seems probable to me at least that there are many different ways this system can fail to work properly. But more about that shortly! Let’s begin with the useful pain.

Nociceptive pain – is considered to be pain that is, as Woolf puts it, our “early-warning physiological protective system”. When we touch something super cold, super hot, or a chemical that can harm us (think chilli pepper!), or meet a mechanical force that activates mechano receptors, our high threshold nociceptors are activated – well in advance of tissue damage, I quickly add. This process activates withdrawal – even in simple single-celled animals – and saves us from harm. When combined with behavioural responses including vocalisation, grimaces and other pain behaviours, we signal to everyone around us that we’re in danger, and others shouldn’t do what we’ve just done (Melzack, Dennis, Kosterlitz & Terenius, 1980).  For me, the cool thing about nociceptive pain is that once you’ve removed that stimulus (got rid of the chilli on your lips, let go of the ice-cube or the hot mug of coffee, or shifted in your seat to relieve your butt) the pain simply goes away. Just like that. How cool?!

Inflammatory pain – is also a useful pain to have. Unlike nociceptive pain, inflammation involves disruption to the tissues, triggering a release of a whole bunch of neurochemicals and cells that quickly lower the point at which nociceptors will fire (making you much more sensitive to mechanical, chemical and temperature input), and increasing the blood supply to allow foreign material, dead cells and spent neurochemicals to be whisked away. Inflammation is reasonably easy to see in the periphery (though not so easy in the internal organs because the innervation is more diffuse) and you’ll all have had it – think sunburn (I know you’re not meant to, but everyone gets sunburned at least once, especially in our NZ sun). With sunburn you’re red, hot and often swollen, and you really know it when you step into the shower! That experience of ouch! to your usual shower temperature (and the ouch! when you towel down) is allodynia, or the experience of pain when a usually comfortable stimulus is applied. You’ll experience hyperalgesia if your mate comes along and slaps you on your sunburned shoulders!

Now both of these mechanisms are useful because they alert us to threat, they make it more difficult to move around, and we often respond to them with changes in our behaviour that act as a signal to others around us. Let’s turn the attention to two mechanisms where there is something gone awry with the nervous system – in other words, useless pain.

Neuropathic pain – is defined by IASP as “pain caused by a lesion or disease of the somatosensory nervous system.” What this means is that there must be an identifiable lesion in the nervous system somewhere – something that can be imaged or tested to demonstrate damage. This could be in the periphery – think of radial nerve entrapment with its characteristic tingling, deep aching and burning over the distribution of the nerve. It could be in the spinal cord itself – think of a complete spinal cord injury where the person is unable to move from the lesion down, and who also gets the same tingling, aching, burning and electric shock pain over the same area. A simple example would be radicular pain where the nerve root is compressed – and this can be seen on imaging, and where the pain is experienced over the same nerve distribution. The final group in this nasty set of neuropathies is when someone has a stroke, where part of the brain is damaged leading to intractable, deep, aching pain with electric shock-like pain just to make it nastier. For a great paper reviewing neuropathic pain, Finnerup and colleagues wrote one published in 2016 (see below), describing a grading system to indicate possible, probable and confirmed neuropathic pain. The hallmark of this pain is that it doesn’t represent tissue damage except in the area of the nervous system where the lesion is located. In other words, that pain down the leg is not where the problem lies in radicular pain – it’s near the spinal cord. So this pain doesn’t have a function for survival – it’s just a horrid nuisance.

The final mechanism is poorly understood – even less well understood than neuropathic pain. This is where ostensibly the nervous system appears intact. The pain experience might be in multiple parts of the body, it could be just in the head (migraine, for example), or it could be just in the shoulder (frozen shoulder maybe?), or it might be everywhere (fibromyalgia). The name isn’t even completely determined – it’s called “dysfunctional” by Woolf, and he collapsed this and neuropathic pain into one mechanism, but I prefer to keep it separate because it’s more helpful for management especially when a neuropathy might be amenable to surgery. Another term, and one I like, is nociplastic – referring to the idea that it’s the unhelpful neuroplasticity of our nervous system that has over-responded to potential threat (Kosek, Cohen, Baron et al, 2016). Some would argue that this mechanism is partly a general tendency to a lower nociceptive threshold, maybe genetic, maybe behavioural (ie we’ve learned to monitor and respond to threat perhaps because of early life experiences), perhaps a diathesis-stress where the predisposition exists but it’s not brought into expression until a stressor, perhaps a virus or an injury, exerts an influence on homeostasis.

Ultimately, pain is an experience that we’ve all had, and one that has individual meaning for each of us based on our previous experiences, predictions for the future, current goals, culture and biology. What a mechanisms-based approach to pain management might mean is better and more accurate management for each one. So we’d be looking to remove that bunion so people can walk more easily; reduce the inflammation in an auto-immune disease; decompress a squished nerve in neuropathic pain and look to altering plasticity in nociplastic pain. But pain is weird and as I said at the very beginning, it’s entirely possible to have more than one mechanism involved – and because pain is not just biology, we’d be foolhardy to think that just by down-tuning the intensity, everyone so treated will go “back to normal”. More on that next week!

 

 

Finnerup NB, Haroutounian S, Kamerman P, et al. Neuropathic pain: an updated grading system for research and clinical practice. Pain. 2016;157(8):1599-1606. doi:10.1097/j.pain.0000000000000492.
Kosek, E., Cohen, M., Baron, R., Gebhart, G. F., Mico, J. A., Rice, A. S., … & Sluka, A. K. (2016). Do we need a third mechanistic descriptor for chronic pain states?. Pain, 157(7), 1382-1386.

Melzack, R., Dennis, S. G., Kosterlitz, H. W., & Terenius, L. Y. (1980). Phylogenetic evolution of pain-expression in animals. Pain and Society, 13-26.

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