Category Archives: Explain Pain

Women and Pain | Part 3

Posted on by under Chronic disease, Chronic pain, Explain Pain, Functional pain, Pain, Women and pain

Women and pain 3

A number of women who come to the clinic with a musculoskeletal complaint will describe other painful syndromes that involve other body systems (see Women and Pain blogs Part 1 & Part 2). These include irritable bowel syndrome (IBS), pelvic pain, dysmennorhoea, endometriosis, bladder dysfunction, jaw pain (TMJ), migraines and widespread musculoskeletal pain. Often hypermobility is also a feature (see blogs here and here) . These are termed functional pain syndromes and require a comprehensive approach to tackle the physical, cognitive and emotional dimensions of the pain and associated problems that impact upon quality of life.

This recent study looked at a cohort of women in Australia and showed that the presence of one condition is associated with the development of another. Certainly in functional pain syndromes we know about the underpinning central sensitisation that is a common theme that manifests in different end-organs or body systems to create the aforementioned conditions. Using strategies to cultivate health within the systems is important, but so is using therapies to target the central mechanisms and driving systems, i.e. the nervous system, the immune system and the endocrine system (including stress physiology).

Only through a detailed assessment and the creation of an environment that permits the patient’s narrative will this vital piece of the puzzle emerge (see Oliver Sack talk about narrative here).

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Clin J Pain. 2013 Mar 12. [Epub ahead of print]

The Relationship Between Incontinence, Breathing Disorders, Gastrointestinal Symptoms, and Back Pain in Women: A Longitudinal Cohort Study.

Smith MD, Russell A, Hodges PW.

Abstract

OBJECTIVES:: Recent studies suggest a relationship between incontinence, respiratory disorders, gastrointestinal (GI) symptoms, and back pain (BP). However, causality is difficult to infer. This longitudinal study aimed to determine whether the presence or development of one disorder increases risk for the development of another. METHODS:: Women from the Australian Longitudinal Study on Women’s Health were divided into subgroups; those with no BP (n=7259), no incontinence (n=18,480), no breathing problems (including allergy) (n=15,096), and no GI symptoms (n=17,623). Each subgroup was analyzed to determine the relationship between the development of the absent condition and the presence or development of the other conditions. Factors with a previously identified relationship with BP were included in analysis.

RESULTS:: Women with pre-existing and/or newly developed incontinence [prevalence ratios (PR): 1.26 to 2.12] and breathing problems (PR: 1.38 to 2.11) had an increased risk for the development of BP, and women with pre-existing and newly developed BP were more likely to develop incontinence and breathing problems (PR: 1.18 to 2.44 and 1.53 to 2.62, respectively). The presence of GI symptoms was also identified as a risk factor for the development of these conditions.

DISCUSSION:: This study provides evidence of a relationship between BP, incontinence, respiratory problems, and GI symptoms in which the presence of one symptom is associated with the development of another. This suggests that common factors may contribute to the development of symptoms across this range of conditions.

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If you suffer functional pains, please call us on 07932 689081 for further information or to book an appointment. See our clinic website here: Specialist Pain Physio Clinics

Reconceptualising pain for better treatment – a revolution? A revelation?

Posted on by under Brain, Brain and pain, Chronic pain, Complex Regional Pain Syndrome, Explain Pain, Pain, Pain Education

Traditionally pain is understood to be an unpleasant experience in the body where a problem exists, and is something to be got rid of as quickly as possible. The so-called ‘biomedical model’ considers which structures require treatment or surgery, stopping at the tissues as the cause of pain. This paradigm has been challenged over the years and rightly so in the light of recent research. Many studies have revealed the underlying physiology within the nervous system, and in particular the brain, and the role of other body systems such as the immune system and endocrine system (hormones) in pain. Understanding that pain is a normal response to a perceived threat has helped mould new treatments and ways of dealing with pain.

The most pertinent discovery and emergent shift in thinking came when it was realised that pain is a brain experience. This came via studies of the brain but also by looking at why phantom limb pain exists and how people present with a range of injuries and such varied levels of reported pain. There are many stories of people suffering severe physical injury yet experience little or no pain at the time.

The fact that we know pain is a brain experience has helped us to understand the many influences upon the pain, especially one’s emotional state. For instance, we know that the danger signals that are sent by the body to the brain via the spinal cord, travel to the emotional centres of the brain to try and give some meaning to the pain. These signals reach the brain and receive scrutiny to work out the level of threat, and this can vary enormously depending upon a range of factors. On activating a widespread group of neurons termed the ’pain matrix’, the output from the brain, a response, can be the pain experience. Knowing that there are many parts of the brain involved has meant that there are now a range of approaches that can tackle the problem of pain.

We are now far more optimistic about treating pain. This is not just with medication, which does have a role when used wisely, but with a range of contemporary treatments, strategies and techniques that address the underpinning mechanisms at a tissue level, spinal cord level and a brain level alongside beliefs, attitudes and behaviours that can be moulded to change the pain. The term used to describe the contemporary approach to pain is ’biopsychosocial’, implying a role for the overlapping biological, psychological and social factors that must be addressed.

CRPS Review 20th February 2012

Posted on by under Brain and pain, Chronic pain, Complex Regional Pain Syndrome, Explain Pain, Pain, Pain Education, Treatment

A selection of papers to peruse:

Predictors of Pain Relieving Response to Sympathetic Blockade in Complex Regional Pain Syndrome Type 1

Anesthesiology: January 2012 – Volume 116 – Issue 1 – p 113–121
doi: 10.1097/ALN.0b013e31823da45f Pain Medicine

van Eijs, Frank M.D.*; Geurts, José M.Sc.†; van Kleef, Maarten M.D., Ph.D.‡; Faber, Catharina G. M.D., Ph.D.§; Perez, Roberto S. Ph.D.‖; Kessels, Alfons G.H. M.D., M.Sc.#; Van Zundert, Jan M.D., Ph.D.**

Abstract
Background: Sympathetic blockade with local anesthetics is used frequently in the management of complex regional pain syndrome type 1(CRPS-1), with variable degrees of success in pain relief. The current study investigated which signs or symptoms of CRPS-1 could be predictive of outcome. The incidence of side effects and complications of sympathetic blockade also were determined prospectively.
Methods: A prospective observational study was done of 49 patients with CRPS-1 in one extremity only and for less than 1-yr duration who had severe pain and persistent functional impairment with no response to standard treatment with medication and physical therapy.
Results: Fifteen (31%) patients had good or moderate response. The response rate was not different in patient groups with cold or warm type CRPS-1 or in those with more or less than 1.5°C differential increase in skin temperature after sympathetic blockade. Allodynia and hypoesthesia were negative predictors for treatment success in CRPS-1. There were no symptoms or signs of CRPS-1 that positively predicted treatment success. A majority of patients (84%) experienced transient side effects such as headache, dysphagia, increased pain, backache, nausea, blurred vision, groin pain, hoarseness, and hematoma at the puncture site. No major complications were reported.
Conclusions: The presence of allodynia and hypoesthesia are negative predictors for treatment success. The selection of sympathetic blockade as treatment for CRPS-1 should be balanced carefully between potential success and side effect ratio. The procedure is as likely to cause a transient increase in pain as a decrease in pain. Patients should be informed accordingly.

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Motor control in complex regional pain syndrome: A kinematic analysis

http://dx.doi.org/10.1016/j.pain.2011.12.018

  • J.C.M. Schildera, , ,
  • A.C. Schoutenb, c,
  • R.S.G.M. Perezd,
  • F.J.P.M. Huygene,
  • A. Dahanf,
  • L.P.J.J. Noldusg,
  • J.J. van Hiltena,
  • J. Marinusa

Abstract

This study evaluated movement velocity, frequency, and amplitude, as well as the number of arrests in three different subject groups, by kinematic analysis of repetitive movements during a finger tapping (FT) task. The most affected hands of 80 patients with complex regional pain syndrome (CRPS) were compared with the most affected hands of 60 patients with Parkinson disease (PD) as well as the nondominant hands of 75 healthy control (HC) subjects. Fifteen seconds of FT with thumb and index finger were recorded by a 60-Hz camera, which allowed the whole movement cycle to be evaluated and the above mentioned movement parameters to be calculated. We found that CRPS patients were slower and tapped with more arrests than the two other groups. Moreover, in comparison with the hands of the HC subjects, the unaffected hands of the CRPS patients were also impaired in these domains. Impairment was not related to pain. Dystonic CRPS patients performed less well than CRPS patients without dystonia. In conclusion, this study shows that voluntary motor control in CRPS patients is impaired at both the affected as well as the unaffected side, pointing at involvement of central motor processing circuits.

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Psychological factors associated with self-perceived pain-related disability among individuals diagnosed with complex regional pain syndrome

by Mann, Jeffrey C., Psy.D., ADLER SCHOOL OF PROFESSIONAL PSYCHOLOGY, 2010, 107 pages; 3452691

Abstract:

Over the last several decades the importance of psychological factors in understanding pain-related disability has grown tremendously. Research has explored many psychological constructs and their relationship to pain related disability with several constructs emerging as clinically significant. The research conducted to date has predominantly focused on individuals with conditions such as low-back, arthritis, or other forms of musculoskeletal pain. To date, there is no research examining the predominant psychological constructs with a population of individuals diagnosed with Complex Regional Pain Syndrome (CRPS). This study had two primary purposes: (a) To examine the relationship between pain catastrophizing, pain helplessness, active coping, passive coping and self-perceived, pain-related disability, (b) to determine the amount of variance in self-perceived, pain-related disability accounted for by pain catastrophizing, pain helplessness, active coping, and passive coping. The research sample included 102 individuals diagnosed with CRPS being treated at a pain clinic. The instruments used to measure the independent variables were: Pain Helplessness Index (PHI), Pain Catastrophizing Scale (PCS), and the Coping Strategies Questionnaire (CSQ). The dependent variable was measured with the Perceived Disability Scale (PDS). Correlation analysis indicated that pain catastrophizing, pain helplessness, and passive coping are all positively correlated with self-perceived, pain-related disability. Multiple regression results indicated that pain catastrophizing, and pain helplessness account for 15.3% of the variance in self-perceived, pain-related disability. Active coping and passive coping did not account for a statistically significant portion of the variance. The findings of this study demonstrate the importance of pain catastrophizing and pain helplessness when treating individuals diagnosed with CRPS and raises doubt about the utility of active coping and the detriment of passive coping. Further investigation is needed to determine the efficacy of interventions focused on modifying pain catastrophizing and pain helplessness as a indirect method of decreasing self-perceived disability.

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Mast Cells: Source of Inflammation in Complex Regional Pain Syndrome?

Mast Cells: Source of Inflammation in CRPS

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Targeting Cortical Representations in the Treatment of Chronic Pain: A Review

  1. G. Lorimer Moseley
  2. Herta Flor

Recent neuroscientific evidence has confirmed the important role of cognitive and behavioral factors in the development and treatment of chronic pain. Neuropathic and musculoskeletal pain are associated with substantial reorganization of the primary somatosensory and motor cortices as well as regions such as the anterior cingulate cortex and insula. What is more, in patients with chronic low back pain and fibromyalgia, the amount of reorganizational change increases with chronicity; in phantom limb pain and other neuropathic pain syndromes, cortical reorganization correlates with the magnitude of pain. These findings have implications for both our understanding of chronic pain and its prevention and treatment. For example, central alterations may be viewed as pain memories that modulate the processing of both noxious and nonnoxious input to the somatosensory system and outputs of the motor and other response systems. The cortical plasticity that is clearly important in chronic pain states also offers potential targets for rehabilitation. The authors review the cortical changes that are associated with chronic pain and the therapeutic approaches that have been shown to normalize representational changes and decrease pain and discuss future directions to train the brain to reduce chronic pain.

RS – out of these papers this is the one that I am most interested in reading. A number of the techniques that I use in the clinic for CRPS are targeting the changes in the brain, including Graded Motor Imagery, 2-point discrimination training, sensorimotor integration and mindfulness. We are both obliged and wise to consider why is it that the brain continues to protect a body part(s) and how has this happened? Herta Flor talks about learning and memory in pain and the conditioning process. Reinforcements for particular beliefs and behaviours can start early after an injury or initiation of a pain state. In these stages we must seek to prevent pathological beliefs developing by using focused education, promote useful behaviours that are reinforced and set goals that sit alongside processes of healing and recovery.

Specialist Pain Physio Clinics in London for CRPS

Musings on Pain – a dialogue between the brain and the foot

Posted on by under Book, Brain, CRPS, Explain Pain, Musings on pain, Neuroscience, Pain, Pain Education

This is a conversation between a brain and a foot. The foot has been a problem for some time now, years even.

The foot was injured at a railway station early one winter’s morning before the sun had appeared. In the distance I could see the usual people waiting on the platform, sheltering under their hats and behind raised collars. Making my way across the concourse, my shoes were barely gripping the floor. It was clear to see that others had skidded in their haste. The rain had only just stopped.

Although it is a foot that hurts, it is not a foot that hurts. What does that mean? Regular readers will remember that pain is a brain experience 100% of the time. The pain is a response by the brain to a perceived threat and allocated an anatomical location via the cortical maps. In this sense, the brain is creating the experience like all other conscious experiences and making it real. This is the best biological response that the brain can muster at that moment for that particular situation. So, although the foot hurts, the foot doesn’t hurt, it is the brain telling you that you need to do something with the foot by making it hurt. Via the brain. Mmm. See Lorimer Moseley talking below:

 

Pain mechanisms (2)

Posted on by under Chronic pain, Explain Pain, Neuropathic pain, Pain, Pain Education, Pain mechanisms, Physiotherapy, Research

Keith Smart has been looking at a mechanisms-based approach to pain. As you may recall from the first piece on pain mechanisms and previous writings, I am a proponent of the view that we should be thinking about pain mechanisms. There are significant advantages to elucidating the underpinning physiological and pathology including understanding the patient’s description of their experience and to be able to focus treatment upon the mechanism(s) for more successful outcomes. Below are the papers by Keith Smart and others who have looked at pain mechanisms.

RS www.specialistpainphysio.com

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Clin J Pain. 2011 Oct;27(8):655-63. doi: 10.1097/AJP.0b013e318215f16a.

The Discriminative validity of “nociceptive,” “peripheral neuropathic,” and “central sensitization” as mechanisms-based classifications of musculoskeletal pain.

Source

St Vincent’s University Hospital, Elm Park, Dublin, Ireland. k.smart@ucd.ie

Abstract

OBJECTIVES:

Empirical evidence of discriminative validity is required to justify the use of mechanisms-based classifications of musculoskeletal pain in clinical practice. The purpose of this study was to evaluate the discriminative validity of mechanisms-based classifications of pain by identifying discriminatory clusters of clinical criteria predictive of “nociceptive,” “peripheral neuropathic,” and “central sensitization” pain in patients with low back (± leg) pain disorders.

METHODS:

This study was a cross-sectional, between-patients design using the extreme-groups method. Four hundred sixty-four patients with low back (± leg) pain were assessed using a standardized assessment protocol. After each assessment, patients’ pain was assigned a mechanisms-based classification. Clinicians then completed a clinical criteria checklist indicating the presence/absence of various clinical criteria.

RESULTS:

Multivariate analyses using binary logistic regression with Bayesian model averaging identified a discriminative cluster of 7, 3, and 4 symptoms and signs predictive of a dominance of “nociceptive,” “peripheral neuropathic,” and “central sensitization” pain, respectively. Each cluster was found to have high levels of classification accuracy (sensitivity, specificity, positive/negative predictive values, positive/negative likelihood ratios).

DISCUSSION:

By identifying a discriminatory cluster of symptoms and signs predictive of “nociceptive,” “peripheral neuropathic,” and “central” pain, this study provides some preliminary discriminative validity evidence for mechanisms-based classifications of musculoskeletal pain. Classification system validation requires the accumulation of validity evidence before their use in clinical practice can be recommended. Further studies are required to evaluate the construct and criterion validity of mechanisms-based classifications of musculoskeletal pain.

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J Man Manip Ther. 2010 Jun;18(2):102-10.

The reliability of clinical judgments and criteria associated with mechanisms-based classifications of pain in patients with low back pain disorders: a preliminary reliability study.

Source

UCD School of Public Health, Physiotherapy and Population Science, University College Dublin, Ireland.

Abstract

Mechanisms-based classifications of pain have been advocated for their potential to aid understanding of clinical presentations of pain and improve clinical outcomes. However, the reliability of mechanisms-based classifications of pain and the clinical criteria upon which such classifications are based are not known. The purpose of this investigation was to assess the inter- and intra-examiner reliability of clinical judgments associated with: (i) mechanisms-based classifications of pain; and (ii) the identification and interpretation of individual symptoms and signs from a Delphi-derived expert consensus list of clinical criteria associated with mechanisms-based classifications of pain in patients with low back (±leg) pain disorders. The inter- and intra-examiner reliability of an examination protocol performed by two physiotherapists on two separate cohorts of 40 patients was assessed. Data were analysed using kappa and percentage of agreement values. Inter- and intra-examiner agreement associated with clinicians’ mechanisms-based classifications of low back (±leg) pain was ‘substantial’ (kappa  = 0.77; 95% confidence interval (CI): 0.57-0.96; % agreement  = 87.5) and ‘almost perfect’ (kappa  = 0.96; 95% CI: 0.92-1.00; % agreement = 92.5), respectively. Sixty-eight and 95% of items on the clinical criteria checklist demonstrated clinically acceptable (kappa ⩾ 0.61 or % agreement ⩾ 80%) inter- and intra-examiner reliability, respectively. The results of this study provide preliminary evidence supporting the reliability of clinical judgments associated with mechanisms-based classifications of pain in patients with low back (±leg) pain disorders. The reliability of mechanisms-based classifications of pain should be investigated using larger samples of patients and multiple independent examiners.

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Man Ther. 2011 Nov 8. [Epub ahead of print]

Self-reported pain severity, quality of life, disability, anxiety and depression in patients classified with ‘nociceptive’, ‘peripheral neuropathic’ and ‘central sensitisation’ pain. The discriminant validity of mechanisms-based classifications of low back (±leg) pain.

Source

St Vincent’s University Hospital, Elm Park, Dublin 4, Ireland.

Abstract

Evidence of validity is required to support the use of mechanisms-based classifications of pain clinically. The purpose of this study was to evaluate the discriminant validity of ‘nociceptive’ (NP), ‘peripheral neuropathic’ (PNP) and ‘central sensitisation’ (CSP) as mechanisms-based classifications of pain in patients with low back (±leg) pain by evaluating the extent to which patients classified in this way differ from one another according to health measures associated with various dimensions of pain. This study employed a cross-sectional, between-subjects design. Four hundred and sixty-four patients with low back (±leg) pain were assessed using a standardised assessment protocol. Clinicians classified each patient’s pain using a mechanisms-based classification approach. Patients completed a number of self-report measures associated with pain severity, health-related quality of life, functional disability, anxiety and depression. Discriminant validity was evaluated using a multivariate analysis of variance. There was a statistically significant difference between pain classifications on the combined self-report measures, (p = .001; Pillai’s Trace = .33; partial eta squared = .16). Patients classified with CSP (n = 106) reported significantly more severe pain, poorer general health-related quality of life, and greater levels of back pain-related disability, depression and anxiety compared to those classified with PNP (n = 102) and NP (n = 256). A similar pattern was found in patients with PNP compared to NP. Mechanisms-based pain classifications may reflect meaningful differences in attributes underlying the multidimensionality of pain. Further studies are required to evaluate the construct and criterion validity of mechanisms-based classifications of musculoskeletal pain.

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Pain. 2011 Jul;152(7):1511-6. Epub 2011 Mar 10.

Identifying neuropathic back and leg pain: a cross-sectional study.

Source

School of Rehabilitation Sciences, Faculty of Health and Social Care Sciences, St. George’s University of London/Kingston University, Cranmer Terrace, London SW17 0RE, UK. I.Beith@sgul.kingston.ac.uk

Abstract

Low back pain is a widespread debilitating problem with a lifetime prevalence of 80%, with the underlying pain mechanism unknown in approximately 90% of cases. We used the painDETECT neuropathic pain screening questionnaire to identify likely pain mechanisms in 343 patients with low back pain with or without leg pain in southeastern England referred for physiotherapy. We related the identified possible pain mechanisms nociceptive, unclear, and neuropathic to standardised measures of pain severity (Numeric Rating Scale), disability (Roland Morris Low Back Pain Disability Questionnaire), anxiety and depression (Hospital Anxiety and Depression Scale), and quality of life (Short Form 36 Health Survey Questionnaire Version 2). In addition, we investigated any relationship between these possible pain mechanisms and leg pain, passive straight leg raise, and magnetic resonance imaging evidence confirming or eliminating nerve root compression. A total of 59% of participants (n=204) reported likely nociceptive pain, 25% (n=85) unclear, and 16% (n=54) possible neuropathic pain. The possible neuropathic pain group reported significantly higher pain, disability, anxiety, and depression, reduced quality of life and passive straight leg raise compared to the other pain groups (P<.05). A total of 96% of participants with possible neuropathic pain reported pain radiating to the leg (76% below the knee); however, leg pain was still more common in patients with nociceptive pain, suggesting that leg pain is sensitive to, but not specific to, possible neuropathic pain. No relationship was demonstrated between possible neuropathic pain and evidence for or absence of nerve root compression on magnetic resonance imaging scans. These findings suggest possible neuropathic pain is less common in low back pain patients referred through primary care and clarifies the usefulness of clinical tests for identifying possible neuropathic pain.

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J Pain. 2011 Oct;12(10):1080-7. Epub 2011 Jul 23.

The neuropathic components of chronic low back pain: a prospective multicenter study using the DN4 Questionnaire.

Source

INSERM U 987, Centre d’Evaluation et de Traitement de la Douleur, Hôpital Ambroise Paré, APHP, Boulogne-Billancourt, France. nadine.attal@apr.aphp.fr

Abstract

The present study investigated the neuropathic components of chronic low back pain (LBP) in patients with and without lower limb pain using the DN4 questionnaire and confirmed its psychometric properties. Patients (n = 132) from 11 French multidisciplinary pain or rheumatology centers were classified by a first investigator into 4 groups derived from the Quebec Task Force Classification of Spinal Disorders (QTFSD): group 1 (pain restricted to the lumbar area); group 2 (pain radiating proximally); group 3 (pain radiating below the knee without neurologic signs); and group 4 (pain radiating towards the foot in a dermatomal distribution, with neurological signs, corresponding to typical radiculopathy). A second investigator applied the DN4 questionnaire to the lower limb (groups 2 to 4) and lower back. A comparison of groups 1 and 4 confirmed the psychometric properties of DN4 (sensitivity 80%; specificity 92%, for a cutoff of 4/10, similar to other neuropathic conditions). In the lower limb, the proportion of patients with neuropathic pain (NP) was related to the distality of pain radiation (15, 39, and 80% in groups 2, 3 and 4, respectively; P < .0001). In the lower back, the proportion of patients with NP was higher for patients with typical radicular pain compared with the other groups (P = .006). Thus, typical radiculopathy has similar characteristics as other neuropathic conditions and is confirmed as the commonest neuropathic syndrome in LBP patients. The observation that neuropathic and nociceptive components of LBP vary in the back and lower limb probably accounts for the discrepancies of reported prevalence rates of NP in LBP. As this study was essentially based on a questionnaire, future studies combining standard clinical sensory testing, specific questionnaires, and more objective assessment of the sensory lesion are now required to further investigate the neuropathic component of chronic LBP. PERSPECTIVE: This study confirms the psychometric properties of the DN4 questionnaire to assess neuropathic pain in patients with low back pain. Neuropathic mechanisms largely contribute to pain in the lower limb as compared to the back, but neuropathic pain is not restricted to typical radiculopathy. This may have significant implications for the choice of treatment strategy in these patients.

Pain mechanisms

Posted on by under Brain and pain, Chronic pain, Explain Pain, Neuropathic pain, Pain, Pain Education, Science, Treatment

Understanding pain mechanisms is the key to effective treatment. The mechanisms that have been studied, written about in science journals and discussed with patients include nociceptive pain, inflammatory pain, neuropathic pain and central sensitisation. Elucidating which are playing a role in the patient’s experience allows the doctor to prescribe the right medication and the modern physical therapist to address the issues of pain in a biopsychosocial manner. I will now clarify the latter point.

In taking a detailed history, observing patterns of movement and protection, assessing the state of the nervous system and health of the body systems, understanding behaviours and the beliefs behind them and learning of the influences upon the individual’s pain experience, one can know about the likely pain mechanisms underpinning the experience. From here the treatment strategies can be chosen to target these mechanisms. For example, top-down approaches for central sensitisation focus on the change in the properties of the central nervous system. The interventions themselves are observant of the amplification that occurs in the spinal cord and higher centres and would seek to dampen the responses with input to the brain that is perceived as normal or non-threatening. This could include sensory stimulation or movements outside of the receptive field, education to reduce fear of movement or imagery to name but a few. Inflammatory pain can also be treated with a top-down approach but local tissue based strategies would also be used. Just to note that the separation of the ‘top end’ (brain and spinal cord) from ‘bottom end’ (tissues) is really a false dichotomy as all conscious experiences are from the brain including what we see and what we feel.

Stephen McMahon and David Bennett, both experts in the field of pain science from King’s College London, produced a poster that describes these mechanisms – click here to visit the page in Nature Reviews Neuroscience. This is what they say about it:

Pain is an unpleasant sensation resulting from the intricate interplay between sensory and cognitive mechanisms. Chronic pain, resulting from disease or injury, affects nearly every fifth person in the Western world, constituting an enormous burden for the individual and society. Sensitization of pain signalling systems is a key feature of chronic pain and results in normally non-painful stimuli eliciting pain. Such sensory changes can occur not just at the sites of injury, but in surrounding normal tissues. This and other observations suggest that sensitization occurs within the CNS as well as within nociceptor terminals. Here we consider the consequences of noxious stimulus applied to our unfortunate builder’s hand, from sensory transduction to pain perception. We describe the structural and functional elements present at different levels of the nociceptive system, as well as some of the changes occurring in chronic pain states. Although our poster highlights a flow of information from the periphery to the CNS, it should be noted that higher brain centres exert both inhibitory and facilitatory controls on lower ones. The challenge for the next decade will be to effectively translate this knowledge into the development of novel analgesic agents for better pain relief.

Richmond Stace – Specialist Pain Physio Clinics, London & Surrey

“We – are – family….” Pain and significant others

Posted on by under Explain Pain, Pain, Treatment, Uncategorized

Although pain is personal and only felt by the individual, the effects pervade to those closely around. It appears to be a two-way street though, with significant others having an impact upon levels of physical activity and evidence of similar attentional biases in chronic pain patients and their caregivers. Have a look at the papers below:

Pain. 2012 Jan;153(1):62-7. Epub 2011 Oct 15.

Do main caregivers selectively attend to pain-related stimuli in the same way that patients do?

Source

Family Research Institute, Shahid Beheshti University, G.C., Tehran, Iran.

Abstract

Despite increasing interest in the attentional biases of pain patients towards pain-related stimuli, there have been no investigations of whether the main caregivers of chronic pain patients also selectively attend to pain-related information. We compared the attentional biases to painful or happy faces of 120 chronic pain patients, 118 caregivers, and 50 controls. Analyses found that both patients and caregivers demonstrated biases towards painful faces that were not observed in control participants or to happy faces. Those patients and caregivers who were high in fear of pain demonstrated greater biases than those low in fear of pain, and the biases of the high-in-fear-of-pain group differed significantly from zero. When sub-groups of caregivers were compared, it was found that biases towards painful faces were not observed for those caregivers who accurately identified the level of pain the patient currently reported. In contrast, those caregivers who overestimated or underestimated the patients’ pain demonstrated biases that were significantly greater than zero. These results add to the growing weight of evidence suggesting that biases towards pain-related stimuli are observed in chronic pain patients, but that the nature of the stimuli is important. In addition, the results suggest that caregivers, particularly those who either under- or overestimate the level of pain that the patient reports, also demonstrate similar biases. Future research should investigate the links between caregivers’ biases and the way in which caregivers respond to pain.

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Pain. 2011 Nov;152(11):2521-7. Epub 2011 Aug 27.

Factors contributing to physical activity in a chronic low back pain clinical sample: a comprehensive analysis using continuous ambulatory monitoring.

Source

Department of Psychology, Eastern Michigan University, Ypsilanti, MI, USA. kalschul@uw.edu

Abstract

Back pain is one of the most common causes of disability in industrialized nations. Despite this, the variables that contribute to disability are not well understood and optimal measurement strategies of disability have not yet been determined. The present study sought to comprehensively assess the strongest predictors of physical activity as a proxy for disability. New patients in a chronic pain specialty clinic completed questionnaires to assess the predictors of physical activity and engaged in 5 days of home data collection wearing an accelerometer to assess physical activity in daily life, which is how disability was operationalised in this study. Analysis of repeated measures patient data revealed that, of 3 composite variables each representing a theoretical model, the model representative of operant factors significantly predicted physical activity. Subsequent analyses showed that pain sensitivity, fear avoidance, and solicitous spousal responses account for a significant amount of the variance in physical activity. These findings suggest that external sources of reinforcement or punishment may serve to influence physical behavior beyond that of internal cues such as fear avoidance or pain. Implications for treatment are discussed, including the potential benefits of specifically incorporating the patient’s sources of operant reinforcement or punishment into treatment.

RS Comment:

To be truly biopsychosocial, significant others and their influences must be considered. Positive strategies to involve and educate care givers, families and friends should form part of the treatment programme. I recommend that all those involved should develop an understanding of the issues of pain. We often listen to and subscribe to the beliefs of those closest to us and this powerful dynamic can be of real benefit. On occasion I am asked whether partners can attend the sessions. I encourage this participation as well as teaching techniques that are required to be used regularly at home, for example desensitisation strategies.

Musings on pain – a book in progress (a)

Posted on by under Book, Brain, Brain and pain, Chronic pain, Explain Pain, Musings on pain, Pain, Pain Education, RSD, Science, Writing

I think and read about pain extensively. Not just the physiology of pain, but the whole affect upon the individual who can suffer in a multitude of ways. We have our own meaning of pain, although most people who I meet have difficulty attaching a sense of meaning to their experience. Broadly speaking, in persisting cases, the pain is deemed to be a thoroughly negative acquaintance that has hung around far too long.

The unwanted house guest, the irritating fly, the frustrating official or an enduring hammering from next door on a quiet Sunday afternoon.

Pain is an emotional and a sensory experience by definition and affected by the physical, the psychological and the social aspects of life, hence the contemporary term ‘biopsychosocial’. There are many influences, a number of which we are not even conscious of at the time. It just hurts.

Click here

Spending a great deal of time with patients,
Listening and hearing the stories of pain and suffering,
Looking and seeing the movement and behaviour changes,
The guarding and protection,
By the brain that must be revealed as the source.

I have heard some incredible histores told to me by the person sitting in front. Listening to the story from the beginning, although often they do not realise that the start point was long ago, I am piecing together the threads and connections. Some of these may seem irrelevant but are actually playing a role in the current time. Every piece of information is received and scrutinsed, nothing discarded until one is certain that there is no involvement.

The classic pain text

This book is a collection of my observations and thoughts about pain. All of these fall back on the contemporary understanding of pain that was really ignited by Pat Wall and Ron Melzack. It is no longer enough or acceptable to think about pain without considering the active role of the brain and the integrated networks of neurons within the brain that can be termed the ‘pain matrix’. However, we do not wish to be too neurocentric about pain and must wisely think about the immune system, endocrine system and autonomic nervous system within our contruct of how the body is protecting itself. For the brain’s ability to defend us is magnificent, our healing powers incredible and our ability to learn phenomenal. Together this creates opportunity, certainly in treating and understanding pain. The emotional centres (limbic system) and prefrontal cortex that are part of the pain matrix can be targeted with ‘informational therapy’ that is high quality pain education that permits deep learning about the body. Changing activity in the matrix will change pain. This does not negate the need to nourish the tissues (muscles, tendons, ligaments etc.) with movement, hands-on treatment and exercise, but we are urged by the science of pain to look beyond the tissues.

RS

CRPS & pain – some things you may not have realised

Posted on by under Brain, Brain and pain, Explain Pain, Illusions, Imagery, Mirror therapy, Pain Education, Physiotherapy, Science, Treatment

Pain is multidimensional. Pain is 100% produced by the brain in response to a perceived threat. The brain allocates a location using the cortical maps, hence why we feel pain in our backs or knees. The brain tries to make sense of the situation, scrutinising what is going on on the basis of past experience (learning) and comparing to the information being received from ALL body systems. This is the reason for the term ‘multisystem output’ as a way of describing what is happening when we are in pain.

The most obvious reason why the pain worsens is that we move, exercise or sit for too long. All of these activities are ‘physical’, asking the tissues to take the strain either rapidly or gradually. On reaching a certain level of strain, lower than normal in cases of sensitivity, nerves start sending danger signals to the spinal cord. From the spinal cord messages are relayed to the brain, still on the subject of danger. Theses are not pain signals. It is only when the brain interprets the information as threatening that the experience of pain is produced – an output from the brain. This is typical in acute situations when the injury or problem is new. The pain is vital, useful and motivates action.

A key point to understand is that the brain does not actually need the tissues to produce pain. Think about phantom limb pain. There is no limb. There are no tissues. But it hurts. It seriously hurts in may cases. So, there are other ‘triggers’ for pain besides actually moving or asking the tissues (muscles, tendons, ligaments, bones etc) to take the strain. Common ‘non-tissue’ circumstances that can amplify pain include stress, circadian rhythms, menstrual cycle, fatigue and thoughts. I think that to take this on board is an enlightening experience. To understand that your pain can be as a result of other reasons besides what you are doing physically can help to explain why it hurts at times when you have not done anything differently and you really cannot comprehend why the pain has increased.

A further influential player in our experiences is vision. I’m really interested in this as the process of ‘seeing’ is much aligned to the way pain is experienced. Information is received by the brain via the optic nerve. The brain must make sense of this data and create a credible outcome, again very much using past experience to judge the present. We still see a bird in his cage despite slender lines dividing his body (the struts of the cage). We don’t see ‘slices’ of a bird. Also consider optical illusions. A great deal of work has been done looking at the use of vision for therapeutic effect, i.e. the graded motor imagery programme. Clearly the mirror box is creating the illusion that the affected side is moving and appearing to be normal. Imagined movements requires us to ‘see’ and feel movement although we are keeping very still. The premotor cortex is very active during these imagined movements, and this part of the brain is involved in the production of pain.

From the book 'Explain Pain' by D Butler & L Moseley

What we are seeing is deemed to be an illusion in some quarters. We all have different experiences and backgrounds. Our beliefs about life and ourselves vary. This will influence what we ‘see’. If you have just watched a scary movie and then go outside into the dark to put the rubbish out, a shadow could be ‘seen’ as something more dangerous than if you have just laughed at a comedy show. Also consider when we see someone injure themselves, again on TV or watching sport. We often wince, grab our corresponding body part or take some other defensive action. Our brains are interpreting someone else’s danger and imprinting this onto our experience, perhaps as a way of helping us to learn that it is dangerous to be in their situation. This is likely due to the mirror neuron network and that when we watch someone else move or position themselves, our virtual body that exists in the brain mimics that position. There are also aspects of empathy in sharing someone’s pain. But, if that position is ‘threatening’ to our brain, we will hurt.

What do we do about that? We use strategies to desensitise and habituate, similar to dealing with any fear. The modern way of tackling pain states, especially those that persist, is using a biobehavioral approach. This means that as well as addressing tissue health with movement and treatment, we must concurrently target the brain and other systems that are involved in the pain experience, e.g. immune, endocrine. It is called ‘top-down’ – ‘bottom-up’. Top-down referring to the brain and our beliefs, understanding, thoughts, how the brain is controlling movement and protecting us; bottom-up signifying the need to nourish the tissues with movement. These exist on a spectrum and both are addressed in a contemporary biopsychosocial treatment programme – see http://www.specialistpainphysio.com/treatment

Below are some interesting abstracts in relation to this blog:

Pain. 2010 Feb;148(2):268-74. Epub 2009 Dec 11.

Pain sensation evoked by observing injury in others.

Source

School of Psychology, University of Birmingham, Edgbaston, UK.

Abstract

Observing someone else in pain produces a shared emotional experience that predominantly activates brain areas processing the emotional component of pain. Occasionally, however, sensory areas are also activated and there are anecdotal reports of people sharing both the somatic and emotional components of someone else’s pain. Here we presented a series of images or short clips depicting noxious events to a large group of normal controls. Approximately one-third of this sample reported an actual noxious somatic experience in response to one or more of the images or clips. Ten of these pain responders were subsequently recruited and matched with 10 non-responders to take part in an fMRI study. The subjects were scanned while observing static images of noxious events. In contrast with emotional images not containing noxious events the responders activated emotional and sensory brain regions associated with pain while the non-responders activated very little. These findings provide convincing evidence that some people can readily experience both the emotional and sensory components of pain during observation of other’s pain resulting in a shared physical pain experience.

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J Cogn Neurosci. 2007 Jan;19(1):42-58.

The neural substrate of human empathy: effects of perspective-taking and cognitive appraisal.

Source

INSERM Unit 280, France.

Abstract

Whether observation of distress in others leads to empathic concern and altruistic motivation, or to personal distress and egoistic motivation, seems to depend upon the capacity for self-other differentiation and cognitive appraisal. In this experiment, behavioral measures and event-related functional magnetic resonance imaging were used to investigate the effects of perspective-taking and cognitive appraisal while participants observed the facial expression of pain resulting from medical treatment. Video clips showing the faces of patients were presented either with the instruction to imagine the feelings of the patient (“imagine other”) or to imagine oneself to be in the patient’s situation (“imagine self”). Cognitive appraisal was manipulated by providing information that the medical treatment had or had not been successful. Behavioral measures demonstrated that perspective-taking and treatment effectiveness instructions affected participants’ affective responses to the observed pain. Hemodynamic changes were detected in the insular cortices, anterior medial cingulate cortex (aMCC), amygdala, and in visual areas including the fusiform gyrus. Graded responses related to the perspective-taking instructions were observed in middle insula, aMCC, medial and lateral premotor areas, and selectively in left and right parietal cortices. Treatment effectiveness resulted in signal changes in the perigenual anterior cingulate cortex, in the ventromedial orbito-frontal cortex, in the right lateral middle frontal gyrus, and in the cerebellum. These findings support the view that humans’ responses to the pain of others can be modulated by cognitive and motivational processes, which influence whether observing a conspecific in need of help will result in empathic concern, an important instigator for helping behavior.

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Hum Brain Mapp. 2009 Oct;30(10):3227-37.

Empathic neural responses to others’ pain are modulated by emotional contexts.

Source

Department of Psychology, Peking University, Beijing 100871, People’s Republic of China. shan@pku.edu.cn

Abstract

Recent brain imaging studies indicate that empathy for pain relies upon both the affective and/or the sensorimotor nodes of the pain matrix, and empathic neural responses are modulated by stimulus reality, personal experience, and affective link with others. The current work investigated whether and how empathic neural responses are modulated by emotional contexts in which painful stimulations are perceived. Using functional magnetic resonance imaging (fMRI), we first showed that perceiving a painful stimulation (needle penetration) applied to a face with neutral expression induced activation in the anterior cingulate cortex (ACC) relative to nonpainful stimulation (Q-tip touch). However, when observation of the painful stimuli delivered to a neutral face was intermixed with observation of painful or happy faces, the ACC activity decreased while the activity in the face area of the secondary somatosensory cortex increased to the painful stimulation. Moreover, the secondary somatosensory activity associated with the painful stimulation decreased when the painful stimulation was applied to faces with happy and painful expressions. The findings suggest that observing painful stimuli in an emotional context weakens affective responses but increases sensory responses to perceived pain and implies possible interactions between the affective and sensory components of the pain matrix during empathy for pain.

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Neuron. 2007 Aug 2;55(3):377-91.

The cerebral signature for pain perception and its modulation.

Source

Centre for Functional Magnetic Resonance Imaging of the Brain, Clinical Neurology and Nuffield Department of Anaesthetics, Oxford University, OX3 9DU Oxford, England, UK. irene@fmrib.ox.ac.uk

Abstract

Our understanding of the neural correlates of pain perception in humans has increased significantly since the advent of neuroimaging. Relating neural activity changes to the varied pain experiences has led to an increased awareness of how factors (e.g., cognition, emotion, context, injury) can separately influence pain perception. Tying this body of knowledge in humans to work in animal models of pain provides an opportunity to determine common features that reliably contribute to pain perception and its modulation. One key system that underpins the ability to change pain intensity is the brainstem’s descending modulatory network with its pro- and antinociceptive components. We discuss not only the latest data describing the cerebral signature of pain and its modulation in humans, but also suggest that the brainstem plays a pivotal role in gating the degree of nociceptive transmission so that the resultant pain experienced is appropriate for the particular situation of the individual.

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Neuroimage. 2009 Sep;47(3):987-94. Epub 2009 May 28.

The influence of negative emotions on pain: behavioral effects and neural mechanisms.

Source

Nuffield Department of Anaesthetics, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK. kwiech@fmrib.ox.ac.uk

Abstract

The idea that pain can lead to feelings of frustration, worry, anxiety and depression seems obvious, particularly if it is of a chronic nature. However, there is also evidence for the reverse causal relationship in which negative mood and emotion can lead to pain or exacerbate it. Here, we review findings from studies on the modulation of pain by experimentally induced mood changes and clinical mood disorders. We discuss possible neural mechanisms underlying this modulatory influence focusing on the periaqueductal grey (PAG), amygdala, anterior cingulate cortex (ACC) and anterior insula as key players in both, pain and affective processing.

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Disclaimer: this blog is for informational purposes only. If you are concerned or unsure about your pain or condition, you must consult with your GP or a health professional.