Pain transition to chronicity

Transcription

1 Pain transition to chronicity Dr Hubert van Griensven PhD MSc(Pain) MCSP DipAc Senior Lecturer in Pain, University of Hertfordshire Independent practitioner, East London Contents Characteristics of acute and chronic pain Transition from acute to chronic pain: Neurophysiological aspects Psychological and social aspects Factors that predict pain chronicity Attitudes and beliefs towards those factors 1

2 Biopsychosocial model IASP definition of pain An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage. Formulated

3 New proposed definition Pain is a distressing experience associated with actual or potential tissue damage with sensory, emotional, cognitive, and social components Understanding of pain has progressed since 1979 Acknowledges sensory & emo features but not others esp cognitive & social Much more than 'unpleasant' old definition trivialises? Subjectivity & self-report stressed in favour of non-verbal behaviours Williams C & Craig K Updating the definition of pain. Pain 157: What is chronic pain? Clinical 3/12, research 6/12 Merskey & Bogduk 94 IASP Duration-based approaches limited and not clinically useful Larner 13 Pain Man Nurs 25(3):707 Healing expected to have completed Loeser & Melzack 99 Lancet 353:1607 Pain from peripheral & central sensitisation when nociceptive input from tissue has diminished Bonica 90 The management of pain 3

4 Clinical meaning of chronicity Failure to adapt Epping-Jordan et al. 98 Health Psych 17(5):421 Problematic pain Barker et al. 14 Br J Pain 8(1):9 Prognostic study Von Korff & Miglioretti 05 Pain 117(3):304 Pain duration Chronic pain Risk Score: Pain intensity Interference with activities Depression Number of pain sites Number of pain days in prior 6 months High Risk Score predictive of long-term pain problems Chronicity as unpredictable state Risk Score more predictive than pain days alone Chronic pain multivariate and highly variable Therefore chronic pain better characterised as having inherently uncertain prognosis This includes the possibility of recovery! Von Korff & Dunn 08 Pain 138(2):267 4

5 Sensory neurophysiology Nociceptive pain Gate open PAIN Tissue damage 5

6 Sensory pathways Aβ C/Aδ Spinal cord 6

7 Sensory pathways Nociceptive Specific Non-Nociceptive Specific Mechano -sensitive WDR C Aδ C Aδ Aβ How do we recognise nociceptive pain in clinic? 7

8 Central sensitisation Pain pathways Amplification PAIN++ Tissue damage 8

9 Woolf C. Central sensitisation: implications for the diagnosis and treatment of pain. Pain 2011; 152(3):S2-S15. Homosynaptic facilitation Facilitatory changes at synapse with 2 neurone Enhanced response to nociceptive input Driven by persistent discharge of primary nociceptive neurone (high or low frequency) NMDA receptor channel critical Later changes in molecular makeup Sandkühler 2013 Spinal cord plasticity and pain, Wall & Melzack's Textbook of Pain 9

10 Woolf C. Central sensitisation: implications for the diagnosis and treatment of pain. Pain 2011; 152(3):S2-S15. Heterosynaptic facilitation Spreading of sensitisation in 2 neurone Unmasking of silent nociceptors Spatial summation Contribution of Aβ fibres to nociceptive activity allodynia Glial cell activation: + & - regulation of transmission including cytokine release 10

11 Synaptic integration How do we recognise central sensitisation in clinic? 11

12 Descending inhibition and facilitation Pain inhibiting systems Evaluation Gate closed Small pain Tissue damage 12

13 Figure 7.1 A major pain-modulating pathway with critical links in the midbrain periaqueductal grey (PAG) and rostral ventromedial medulla (RVM). Regions of the frontal lobe and amygdala project directly and via the hypothalamus (H) to the PAG. The PAG in turn controls spinal nociceptive neurons through relays in the RVM and the dorsolateral pontine tegmentum (DLPT). The RVM contains both serotonergic and non-serotonergic projection neurons; the DLPT provides noradrenergic innervation of the dorsal horn. The RVM exerts bidirectional control over nociceptive transmission in the dorsal horn. (Circuitry within the dorsal horn is outlined in detail in Fig. 7.5.) Downloaded from: Wall and Melzack's Textbook of Pain, 5th Edition (on 22 January :10 PM) 2005 Elsevier The rostro-ventral medulla Projects to dorsal horn regulates inhibition or facilitation of nociceptive transmission Influenced by nociceptive input & higher centres Physiological substrate for link between emotions, cognitions and pain processing Also projects to higher centres exact function unclear Heinricher & Fields 2013 in Wall & Melzack's Textbook of Pain; Heinricher 2015 in Postoperative pain IASP Press; Tracey & Mantyh 2007 Neuron 55:

14 BRAIN Woolf C. Central sensitisation: implications for the diagnosis and treatment of pain. Pain 2011; 152(3):S2-S15. Disinhibition & facilitation BRAIN Woolf C. Central sensitisation: implications for the diagnosis and treatment of pain. Pain 2011; 152(3):S2-S15. 14

15 Descending control in practice Central control plays a role in all sensory states Key component in development of central sensitisation Adaptive or maladaptive Includes stress-induced analgesia Persistent pain may be associated with poor inhibitory control Physiological and psychological components. Heinricher & Fields 2013 in Wall & Melzack's Textbook of Pain; Porreca et al Trends Neurosci 25: ; Ren & Dubner 2002 Pain 100: 1-6 Influence on CNS processing Peripheral drivers Non-noxious sensory input Threat value of the pain Attention and distraction Emotional state and trait Descending inhibition/facilitation Genetics 15

16 How do we recognise descending modulation in clinic? Managing CNS processing Reduce peripheral drivers Maximise non-noxious sensory input Maximise descending inhibition: Reduce threat value Patient education Prediction replacement Graded exposure Goal setting and goal attainment Work, leisure, social life Moseley 2003 A pain neuromatrix approach Manual Therapy 8(3):

17 Pain physiology education Threat value of pain affects the way pain is perceived Relationship nociception pain varies Adaptive v maladaptive pain Pain transmission and pain perception can be influenced Moseley & Butler 2015 Evidence is promising but limited Clarke, Ryan & Martin 2011 Manual Therapy 16: 544-9; Engers et al Cochrane Database; Louw et al Arch Phys Med Rehab 92(12): Time for a break 17

18 Predictors of chronicity Prognostic factors for poor outcome in MSK pain Pain of higher severity & longer duration Multiple pain sites Previous pain episodes Higher somatic perceptions / distress Anxiety and / or depression Low social support Older age Higher disability Greater restriction Mallen et al Br J GP 57:

19 Psychological risk factors for chronicity Psychosocial variables linked with transition from acute to chronic pain These variables are more important than biomedical or biomechanical factors Attitudes, pain cognition, fear-avoidance Depression, anxiety, distress Sexual and / or physical abuse Self perceived poor health Linton 2000 Spine 25(9): Psychological predictors for persistent LBP & disability Psychological distress Low mood Somatisation Catastrophising Pincus et al Pain 154(11):

20 Are risk factors modifiable? Smoking Obesity Depression Does modification work in practice? Does modification lead to different outcomes? Who is best placed to modify risk factors? Ultra-short screening questions In the past month, has your pain been bad enough for you to stop many of your day-today activities? In the past month, has your pain been bad enough to make you feel worried or low in mood? Barker et al

21 Other ultra-short questions What do you think is causing your pain? What is the best explanation you have had for your pain? How do you see the future? Suppose that one night there is a miracle: while you were sleeping your pain was taken away. What would change? What would you do? de Shazer 1991, De Jong & Miller 1995, Nichols et al Startback back pain items 1. My back pain has spread down my leg(s) at some time in the last 2 weeks. 2. I have had pain in the shoulder or neck at some time in the last 2 weeks. 3. I have only walked short distances because of my back pain. 4. In the last 2 weeks, I have dressed more slowly than usual because of back pain. 5. It s not really safe for a person with a condition like mine to be physically active. 6. Worrying thoughts have been going through my mind a lot of the time. 7. I feel that my back pain is terrible and it s never going to get any better. 8. In general I have not enjoyed all the things I used to enjoy. 9. Overall, how bothersome has your back pain been in the last 2 weeks? 21

22 Barriers to addressing predictors of chronicity Common excuses for not dealing with psycho-social aspects Chaotic and overwhelming Lack of time Lack of training Not my job Not acceptable to patients Biomedical orientation 22

23 Clinician attitudes & beliefs Biomedical orientation towards pain may make patients fear-avoidant Clinicians with biomedical orientation are less likely to follow evidence-based guidelines Houben et al Pain 9:173-83; Holden et al Arthritis & Rheum 61: ; Darlow et al Eur J Pain 16:3-17 Do the test! Reflect on practitioner beliefs & attitudes Ask for feedback Bishop et al Pain 132: ; Nijs et al Manual Therapy 18: PT attitudes and beliefs Limited recognition of the role of social, cognitive & emotional factors in LBP Some stigmatisation of patients who display these factors Limited willingness to engage with these factors Synnott et al

24 PT training Training has biomedical focus PTs perceive training to be limited in: Communication skills Identifying and managing psychological and social issues Synnott et al Training in applied pain physiology, pain assessment & pain management likely to be limited for all medical professions Watt-Watson et al. 2009, Briggs et al Effects of training on care Specific training can improve pain-related knowledge, skills, attitudes and beliefs. However, patient perception of PT may not change Overmeer et al

25 What do patients value? Being taken seriously; affirmation Explanation during & after examination Understandable information: Causes / maintaining factors of pain Realistic reassurance Psychological and social issues Options Collaboration re treatment & management Coole et al. 2010; Laerum et al. 2006; Snelgrove & Liossi 2013; Toye et al Addressing psycho-social issues Risks of ignoring: Treatment ineffective Chronicity Underlying issues may manifest differently Reinforcing unhelpful cognitions & behaviours Advantages of addressing: Improve outcomes and adherence Patient-centred care Promote self-management Achieve realistic & value-led goals But also: patients still want to be touched! 25

26 Appropriate distress Eg loss of activity important to the person, concerns about loss of income. Acknowledge the patient s experience Be open to discuss their problem as they see it Adopt a problem-solving approach Be clear about your abilities and boundaries T Pincus Thank you 26