Pain

Question 1

What is pain?

Answer 1

 Pain – the sensory and emotional experience of
discomfort, which is usually associated with actual or
threatened tissue damage or irritation.
 Plays an important protective feedback function
 Most common medical complaint
 More than 80% of all visits to physicians

Question 2

Qualities of pain

Answer 2

 Sharp
 Dull
 Burning
 Cramping
 Itching
 Aching
 Shooting
 Throbbing

Question 3

Organic vs. psychogenic pain

Answer 3

 Organic pain – discomfort from tissue damage (e.g.,
stubbed toe, scraped knee)
 Psychogenic pain – discomfort without clear organic
basis (e.g., pain disorder – a somatoform disorder)
 In the past:
Physicians and researchers thought organic and
psychogenic pain were completely separate.
 Today:
Physicians acknowledge that both physical and
psychological factors influence the pain experience.

Question 4

Acute vs. chronic pain

Answer 4

 Acute pain – temporary, lasts less than 6 months
Typically has a definable cause; treated with painkillers
Associated with an increase in anxiety levels
 Chronic pain – lasts longer than 6 months
E.g. from rheumatoid arthritis
Associated with high anxiety levels, hopelessness,
helplessness
Influences other behaviours – e.g., sleep
sleep deprivation then increases sensitivity to pain

Question 5

Types of chronic pain: Part 1

Answer 5

 Chronic recurrent pain:
Stems from benign causes
Repeated episodes of pain and episodes of no pain
e.g., myofascial pain syndrome
 Chronic intractable benign pain:
Discomfort that is present all the time
Not related to a malignant condition
E.g., chronic back pain

Question 6

Types of chronic pain: Part 2

Answer 6

 Chronic progressive pain:
Continuous discomfort
Associated with a malignant condition
Increases in intensity as condition worsens
e.g., rheumatoid arthritis, cancer

Question 7

Types of pain

Answer 7

 Referred pain:
Pain originating from internal 
organs perceived as coming 
from other parts of the body
E.g. heart attack
Internal organs and skin use 
same pathway in the spinal cord
Due to not being used to pain originating from 
internal organs

Question 8

Pain signals

Answer 8

 Nociceptors – nerve endings that respond to pain
stimuli and signal injury to the brain
Found in: skin, blood vessels, muscles, joints, etc.
 Types of Afferent Peripheral Fibres:
A-delta fibres – coated with myelin, quick
transmission
C fibres – slower impulse – dull, burning, aching
pain

Question 9

Pain without detectable damage

Answer 9

 Neuralgia
 Recurrent shooting/stabbing pain along course of nerve
 Causalgia
 Renamed “Complex regional pain syndrome”
 Severe burning pain triggered by minor stimuli (e.g., clothing, puff of air), can occur spontaneously
 Sometimes where body has healed – e.g., gunshot, stabbing
 Fibromyalgia
 Chronic widespread pain with unknown (probably multiple) causes
 Phantom Limb Pain
 Pain in limb no longer there
 Can persist for months and even years

Question 10

Theories of pain

Answer 10

Early theories of pain:
 Specificity theory:
 Pain receptors, nerves, brain region; direct and
automatic link between cause of pain and brain
 Pattern theory:
 Similar; level of pain determined by nerve
impulses from damaged tissue
 Commonalities of these theories:
 Pain caused by damaged tissue
 Psychological consequences only
 Pain as an automatic response with a single cause
 Psychogenic pain acknowledged but only when no
organic cause can be found

Question 11

Problems with early theories of pain

Answer 11

 Medical treatments (drugs and surgery) tend to work
for acute pain only.
 Degree of tissue damage and reports of painful
sensations differ (e.g. soldiers requesting less pain
relief than civilians).
 Phantom limb phenomenon; pain felt as coming from
the place where the amputated limb used to be.

Question 12

Gate-Control Theory of Pain: Part 1

Answer 12

 Developed in 1960s by Melzack and Wall
Integrated physiology with psychology and improved
preceding theories; complex pathway mediated by a
network of interacting processes.
 The Basics of Gate-Control Theory of Pain
There is a “gating mechanism” located in the spinal cord
(substantia gelatinosa of the dorsal horn)

Question 13

Gate-Control Theory of Pain: Part 2

Answer 13

Travelling through the gate:
1. Signals of noxious stimulation from nerve fibres at
injury site enter gating mechanism.
2. Brain also sends information about the
psychological state of the individual (e.g. attention,
anxiety, memory of previous experience).
3. If signals pass through gating mechanism, they
activate transmission cells.
4. Transmission cells send impulse to the brain.

Question 14

Gate-Control Theory of Pain: Part 3

Answer 14

How the gate works
KEY in this theory: gate can be opened or closed
If open: transmission cells send impulses freely
Gates closed/partially closed: output of transmission cells is
inhibited.

Question 15

Gate-Control Theory of Pain: Part 4

Answer 15

What Controls Opening and Closing of the Gate?
 (1) The amount of activity in the pain fibres
Activity of the large fibres due to injury
The stronger the noxious stimulation – the more active the pain fibres
 (2) The amount of activity in other peripheral fibres
A-beta fibres – carry information about harmless
stimulation – touching, rubbing, light scratching
Stimulation of the small fibres (e.g. gentle massage, TENS,
medication) tends to close the gate (inhibits pain neurons)

Question 16

Gating example – TENS machine

Answer 16

 TENS = Transcutaneous Electrical Nerve Stimulation
 Used for surgery, trauma, long-term pain, or child birth
 How it works:
 The nerve cannot carry pain impulse and non-pain impulse (from TENS) simultaneously –therefore pain signal is overridden
 Also encourages body to produce endorphins

Question 17

Gate-Control Theory of Pain: Part 5

Answer 17

 What Controls Opening and Closing of the Gate?
 (3) Messages that descend from the brain
 Efferent pathways (brain to spinal cord) can open or close the gate
 E.g., emotional factors such as anxiety (open gate) or excitement (close)
 Behavioural factors, such as focusing on pain (open) or concentration on other things or distraction (close)
This pathway explains why people who are distracted by environmental stimuli may not notice the pain.

Question 18

Problems with Gate-Control Theory

Answer 18

 No clear evidence yet for precise location of the
supposed “gate”.
 Unclear how exactly the psychological factors
interact with the organic basis of pain.

Question 19

Inhibition of pain

Answer 19

 Stimulation-produced analgesia (SPA)
 Stimulation to the periaqueductal gray
area of the midbrain produces an
insensitivity to pain (e.g. TENS,
acupuncture); Kotzé & Simpson (2008)
 Serotonin activates inhibitory interneurons
 release endorphins at pain fibres
 endorphins inhibit release of substance P (pain message) from pain fibres

Question 20

Pain and the role of learning

Answer 20

 Classical conditioning: past experience and association can exacerbate pain (e.g., going to the dentist after a bad experience)
 Jamner & Tursky (1987): migraine sufferers react with more anxiety to words associated with migraine
 Operant conditioning: Reinforcement can exacerbate pain (e.g., getting attention)

Question 21

Pain and the role of affect

Answer 21

 Anxiety
Anxiety and worry make pain worse; problem with
chronic pain, which is harder to treat
High trait anxiety predicts pain experience
 Fear
Fear and fear avoidance beliefs (e.g., “It will hurt if I
walk”) can exacerbate pain and predict transition from
acute to chronic pain
Fear of pain might lead to hyper-vigilance of pain and
thus more intense experience of it.
Treatment could work on reducing these avoidance
behaviours.

Question 22

Cognitions in pain

Answer 22

 Catastrophising
 Rumination (“I can feel my knee click”); focus on threatening information
 Magnification (“I will become paralysed”); overestimation of threat
 Helplessness (“Nobody can help me and I just can’t bear the pain anymore”); underestimating personal resources to cope
 Each predict pain intensity
 Meaning
 Positive meaning (e.g., childbirth, muscle strength training) may reduce pain
 Negative meaning (e.g., serious illness) may increase pain

Question 23

Cognitions and behaviour in pain

Answer 23

 Self-efficacy
Past positive experiences may improve pain
Locus of control
 Attention
Attention to pain increases pain
Distraction decreases pain
Additionally, pain demands attention leaving less attention to other tasks

Question 24

Assessing pain: Part 1

Answer 24

 Interviews:
History of the pain, emotional adjustment, lifestyle factors,
impact on interpersonal relations and work
 Pain Questionnaires (e.g. McGill Pain Questionnaire)
 Verbal description of pain
 Pain Rating Scales
Box Scale (0 = no pain, 10 = worst possible pain)
Visual Analogue Scale:

Question 25

Assessing pain: Part 2

Answer 25

 Observational assessment
Generally considered unreliable, but sometimes required
E.g. children, non-verbal adults, some terminally ill adults
 Physiological measures
Assessment of inflammation
Measure of sweating, heart rate, skin temperature
Also often not reliable

Question 26

Managing pain

Answer 26

 Clinical pain – any pain that requires professional
care
Acute
>. Why is this pain important to manage?
- Occurs during surgical procedures
- Following surgical procedures
- Impacts patient adherence to treatment (e.g., returning to the dentist for another filling)
Chronic
>. Why is this type of pain important to manage?
- Important in chronic illness – e.g., arthritis, cancer
- Needs to be managed properly in terminal cases
- Important to the improvement of quality of life

Question 27

Acute clinical pain

Answer 27

 E.g., pain following abdominal
surgery
 Many patients experience greater-than-necessary pain following surgery
 Can lead to:
 Increased infection, slow wound healing (pain and related stress impairs immune and endocrine functioning)
 Medical complications and potentially death

Question 28

Chronic clinical pain

Answer 28

 e.g., lower back pain, arthritis, cancer
 Can lead to increased hopelessness and despair in the transition from acute chronic pain
 While some studies found a relationship between the neurotic triad of personality of the MMPI (hypochondriasis, depression, hysteria) and chronic pain (Armentrout et al., 1982; McGill et al., 1983), others found that the MMPI is not a reliable tool to predict pain perception (Cox et al., 1978; Naliboff et al., 1982)
 Other major issues with chronic clinical pain:
 Interpersonal and emotional difficulties
 Excessive drug use
 Frequent sleep disturbance

Question 29

Medical treatment for pain

Answer 29

 Surgical methods
More likely to be effective for
acute pain
Other methods:
Synovectomy – removing membranes of arthritic joints
Spinal fusion – fusing vertebrae to treat severe back pain;
typically using donor bone material to join vertebrae

Question 30

Behavioural and cognitive treatment: Part 1

Answer 30

 Goals: help patients cope more effectively, and reduce
their reliance on drugs; moving client out of comfort
zone back into activities that they had been avoiding.
Operant Approach
 Especially used with children
 Reinforcement of desirable behaviour (e.g., if you do this
exercise, then we can play a game)
 Give praise for desirable activities – sleeping through
naptime, not complaining

Question 31

Behavioural and cognitive treatment: Part 2

Answer 31

 Relaxation and Biofeedback
Helps reduce stress (which is linked to chronic
pain, tension headaches, etc)
E.g., progressive muscle relaxation
E.g., biofeedback – learning control over bodily
functions such as heart rate (through electronic
devices)

Question 32

Cognitive treatment of pain: Part 1

Answer 32

 (1) Distraction
Focusing on a nonpainful stimulus in the immediate environment
Factors:
Attention – greater attention, lower pain ratings
Whether the distractor is interesting
– e.g., watching a movie, being asked to reflect on what’s going on in the movie (used when giving needles to children)

Question 33

Cognitive treatment of pain: Part 2

Answer 33

 (2) Imagery
Guided imagery –alleviation through imaging
mental scene unrelated to the pain
Useful in acute pain
Not clear in terms of its use in chronic pain
Difficult for some people

Question 34

Cognitive treatment of pain: Part 3

Answer 34

 (3) Pain redefinition:
 Replacing maladaptive thoughts about threat and harm with constructive and realistic thoughts
 Focus often on the internal dialogue
 Coping statements: emphasise person’s ability to tolerate
discomfort (e.g., “It hurts, but you’re in control”)
 Reinterpretative statements: designed to negate the
unpleasant aspects of discomfort (e.g., “It’s not the worst
thing that could happen”)
 Useful for those undergoing medical procedures
 But be careful not to create feelings of guilt

Question 35

Cognitive treatment of pain: Part 4

Answer 35

 Pain Redefinition (continued)
1. Medical procedure information – can be provided
by a therapist reduces anxiety and discomfort
2. Coping with chronic pain – therapist can promote
active coping and pain acceptance
 Have them perform activities to see they have enjoyment
even with pain present
3. Reducing illogical thoughts in chronic pain patients
 Helping to reduce overall discomfort

Question 36

Effectiveness of MBSR

Answer 36

 Pearlman et al. (2010) exposed novice and experienced meditators to painful thermal stimuli and asked them to engage in focused attention in one
condition and open monitoring in another.
 During the open m. condition, experienced meditators reported the same intensity of pain, but much less unpleasantness.
 Another study found lower pain sensitivity in experienced meditators compared to controls, as well as changes in cortical structure (Grant et al., 2009).
 Zeidan et al. (2009) gave people 1-hour mindfulness training for 3 days and then gave painful electrical stimulation. Mindfulness training reduced pain ratings and anxiety. Mathematics distraction had some effect on mild pain, but relaxation did not work.