Wk 9: Pain

  1. Dimensions of pain
    • Types; stabbing, shooting, throbbing, aching
    • Severity: non, mild, severe
    • Pattern: continuous, intermittent
  2. Pain distributions
    • Chronic pain varies by age: lowest in 18-25, highest in 75+
    • More common in females than males
  3. How is pain assessed?
    • Beyond self report, look at pain thresholds
    • Cold pressor task: measures body response to cold water. Count how many seconds until don't want to tolerate anymore.
    • Pressure pain: automated device, how much pressure will you tolerate until you decide it is pain (label as pressure to pain)
    • Sensation from warmth/heat to pain.
  4. Pain perception
    • Pressure pain thresholds vary by location (diff parts of body) and between people and within people over time.
    • Variability in pain threshold is bigger than sensations such as warmth.
    • Same with mechanical pressure, can detect different pressures but range for pain is very large.
  5. Visual analogue scale
    • Table/graph between clinical severity and pain experience.
    • Different between people and does not necessarily rely on severity.
  6. Twin studies and pain
    • In pain, heritability estimates range from 25-60% suggesting that some of the variation in pain sensitivity is genetically driven.
    • Genetic differences in perceptions of pain.
    • Unsuccessful in identifying specific genes.
  7. How is pain processed?
    • Classic models assumed individual nerves (nociceptors) transmitted pain and that was it. 
    • Challenged by several observations-
    • Phantom limb pain: may people with amputated limbs report pain
    • Intact pain neurons but no experience of pain: congenital insensitivity to pain
    • Psychosocial factors modulate pain sensitivity and reporting
  8. Gate control theory
    • A 'gate' at spinal column controls whether pain receptors in the skin and organs is transmitted on to the brain.
    • "gate" can incorporate both information from periphery along with info from the brain down eg. emotions, cognitions.
    • Balance of activation from peripheral pain signals and inhibition from brain results in final pain experienced/perceived.
    • Gate control theory integrates and accounts for psychosocial modulation of pain experiences, but does not account for things like phantom limb
  9. Neuromatrix theory of pain
    • Pain is a multidimensional experience
    • Activation of a broad neural network triggers the experience of pain.
    • Network may be activated by sensory input from nociceptors, but the network once established may also get triggered independent of sensory input.
    • Essentially pain is a 'brain' level phenomenon.
    • Neuromatrix can incorporate a number of factors including psychosocial, cognitive, attentional factors in the experience of pain.
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  10. Pain and Affect
    • Although pain includes a sensory component, the experience also involves an affective component.
    • The same way that fear or distress are emotions that serve to push us to act, the affective component of pain motivates us to seek ways to resolve pain.
    • Imaging studies show that acute pain cessation is associated with activity in the NUcleus Accumbens, a brain region associated with processing of aversion and reward (relief).
    • In people wiht chronic pain, no 'relief' if acute pain stops but chronic is still there.
    • Some suggestion that chronic pain begins to be processed more heavily in regions of the brain associated with affective responses
  11. Pain and affect continued
    • Even people with chronic pain compared to baseline: inducing positive mood improves pain tolerance, inducing negative mood decreases pain tolerance. 
    • Longitudinal studies show that: people with chronic pain who are not depressed at baseline are several time more likely to develop depression to people without chronic pain.
    • People who are depressed but do not have chronic pain are more likely to develop chronic pain over time than people who had neither at baseline.
    • Bi-directional relationship between pain and mood.
  12. Pain and hand holding
    • Hand holding has shown pain reducing effect
    • Co-activity in brain regions higher in hand holding than no hand holding conditions
  13. Pain and coping in adults
    • Active coping: purposely engaging in adaptive cognitive behavioural strategies to manage pain. Linked to lower levels of pain, improved depression, fatigue and medical adherence.
    • Passive coping: withdrawing or giving up instrumental control over pain. Linked to higher levels of pain, functional disability or depression.
    • Emotion-focused coping: efforts to regulate emotional responses to stressor. Linked to increased pain.
    • Positive religious and spiritual coping: linked to positive mood and social support
    • Negative religious etc: linked to less positive mood
    • Catastrophising: the tendency to focus on and exaggerate the threat value of painful stimuli and negatively evaluate one's ability to deal with pain: heightened pain and disability
  14. Psychological treatment
    • Self regulatory treatments: biofeedback, relaxation training, mindfulness
    • Behavioural treatments: operant, fear avoidance
    • Cognitive behavioural treatments
    • Acceptance and commitment therapy
  15. Biofeedback
    • Connected to some continuous marker of behavior/physiology
    • – breathing
    • – Heart rate
    • – Brain monitoring, etc.
    • Practice becoming aware of these changes and attempting to modulate them
  16. Relaxation
    • Often combined with other treatments
    • Identify states of tension in mind or body
    • Apply some technique for relaxation:
    • Deep breathing
    • Progressive relaxation: start at bottom of body, tense and relax muscle groups gradually moving up.
  17. Mindfulness
    • Mindfulness meditation benefits on: stress management, pain management
    • Involves: relaxation, focused attention on present moment without interpretation/labelling
    • Experience present in 'raw' form
    • "detached observer' of own experience

    Mindfulness can help detach sensation of pain with the affective experience of distress associated with pain
  18. Operant behaviour therapy
    • Typically targets fear behaviours: verbalisation, facial expressions, guarded/restricted movement
    • These behaviours may be naturally reinforced; guarded movement may temporarility result in some pain reduction.
    • Facial expressions lead to support/sympath.

    • Not all these behaviours may be helpful.
    • Guarded movements may not reduce actual damage and may put strain on other regions causing new damage.
  19. Fear avoidance
    • Fear avoidance may drive people to avoid a variety of experiences associated with fear or potentially painful experiences.
    • Can exacerbate problems through disuse or promoting unhelpful behaviours (eg. reducing physical activity)
  20. Cognitive behavioural therapy (CBT)
    • Goal oriented, structured therapy targeting behaviours and cognitions and emotions that may be unhelpful
    • Try to reduce unhelpful behaviours.
    • Education around role of cognitions and behaviour, build self efficacy
    • skills such as relaxation
  21. cceptance and commitment therapyL
    • Emphasises acceptance and mindfulness
    • CBT focuses on skills to address and control experiences and feelings.
    • ACT focuses on awareness and acceptance of experiences and feelings.
    • Struggling or fighting pain may cause suffering and more problems
  22. Psychological treatments summary
    • Reducing ratings of pain intensity
    • Reducing distress, depression, anxiety, worry surrounding pain
    • Increasing engagement with life goals and increasing function
Card Set
Wk 9: Pain
Wk 9: Pain