Pain Mechanism and Management

Question 1

Define acute pain

Answer 1

an unpleasant sensory or emotional experience that is associated with actual or potential tissue damaging stimuli

Question 2

what can pain be influenced by

Answer 2

• expectations
• significance
• emotions
• context in which it is experienced for example if you don’t know where it is it can be more frightening

Question 3

Name two theories of pain

Answer 3

Specificity theory

Gate control theroy

Question 4

describe specificity theory

Answer 4

This is the idea that a specific stimulus leads to a response and this allows su to experience pain

• there is a direct and autonomic linked between cause of pain and signal through spinal cord to brain receptors resulting in sensitisation
• ignores the effects of emotion and pain, attention and distraction, and the individuals meaning of pain

Question 5

Describe gate control theory

Answer 5

when the gate is open in the spinal cord pain is experienced whereas if the gate is closed in the spinal cord that there is no pain

• idea that pain is a perception rather than a sensation
• most pain has peripheral, spinal and brain based controls and there is individual variation

Question 6

describe how gate control theory works

Answer 6

Gate open

• noxious stimulus activates pain control fibres A delta and C fibres
• these input into the spinal cord
• signals from the brain such as tension, depression, boredom and focus on pain inputs into the spinal cord as well
• these both leads to transmission up to the brain which leads to the feeling of pain

Gate closed

• stimulate pain fibres C and A delta
• this is inhibited by analgesia medication
• can also inhibit this by counter-stimulation for example by rubbing, TENS and acupuncture which activates other perisperhal fibres
• these inhibit input from the brain as well
• therefore the transmission cells are inactive

Question 7

where is the gate located in gate control theroy

Answer 7

spinal cord

Question 8

What is counter stimulation

Answer 8

• can also inhibit this by counter-stimulation for example by rubbing, TENS and acupuncture which activates other perisperhal fibres

Question 9

what is a TENS machine

Answer 9

• this is an electrical stimulation machine

Question 10

what is the most common cause of chronic pain

Answer 10

• arthritis

Question 11

name some facts of chronic pain

Answer 11

25% of adults

• up to two years to gain adequate control
• 20% lose a job
• 20% with major depressive disorder
• 15% report wish to die
• 21% of suicide attempts are patients being managed for chronic pain

Question 12

define chronic pain

Answer 12

• A continued state of suffering, pain persists past the healing phase following an injury

Question 13

What are the three main areas in the brain that are important in chronic pain

Answer 13

• Sensory/discrimitive pain – localisation in time and space, assessment of intestine, lateral system, lateral thalamic nuclei S1, S2, SMA
• Affective/motivational – emotional/unpleasant aspects, reward in escape, medial system (HG medial thalamic nuclei, ACC, insula)
• Cogntivie/evaluative – interpretation of pain and its meaning, cogntivie system (ACC DLPC)

Question 14

What does pain involve and what does this allow for

Answer 14

Pain is an integrated constructive that involves

• Sensory
• Emotional and motivational
• Cogntivie and evaluative

This allows for

• Threat assessment and memory of pain
• Repetition of behaviour

Question 15

What is the most common mental disorder associated with pain

Answer 15

MDD (major depressive disorder/clinical depression) is the most common mental disorder associated with pain

Question 16

what does pain do to MDD

Answer 16

Pain intensity increases with MDD severity

Question 17

Describe how pain and MDD are linked

Answer 17

MDD can result in chronically painful symptoms while chronically painful symptoms can also result in MDD

Question 18

name the neurotransmitters that are involved in chronic pain

Answer 18

• Serotonin
• Noradrenaline
• Dopamine
• Opioid system
• Dysfunction in 1 or more of these circuits results in chronic pain/MDD and anxiety

Question 19

what do 
- -	Serotonin 
-	Noradrenaline 
-	Dopamine 
-	Opioid system 
do that results in a decrease in pain/MDD

Answer 19

• Serotonin = surpasses sensation of normal bodily functions
• Noradrenaline = surpasses sensation of normal bodily functions
• Dopamine = salience - this is the perceptual quality by which an observable thing stands out relative to its environment
• Opioid system = prevents spread of pain, dampens pain, reinforces behaviour

Question 20

what 3 systems are linked

Answer 20

• Pain, MDD and anxiety these may reflect disturbances in multiple systems

Question 21

What are the 4 types of pain behaviours and give examples

Answer 21

Negative effect - bad mood, irritability, upset

Facial/audible expression of distress - gritting teeth, moaning

Distorted ambulation or posture - limping, stooping, holding affected area

Avoidance of activity - lying down, staying home from work, avoiding physical activity

Question 22

describe pain and addiction

Answer 22

• Aberrant drug related behaviours is 11.5

Question 23

What is addiction associated with

Answer 23

Addiction is associated with changes in

• Serotonin – mood is stimulated
• Noradrenaline – mood is stimulated
• Dopamine – salience – importance- increased likelihood of repetition
• Opioid systems – reinforces the behaviour through pleasure
• Entry into the circuit can be direct and from either side

Question 24

Describe how cognitive behaviour therapy works

Answer 24

cognitive techniques

• distraction - focusing on a non painful stimulus
• non pain imagery - focusing on mental scenes unrelated to pain
• pain redefinition - replace feeling of threat with realistic thoughts about the pain experience and capacity to cope

Behavioural techniques

• medication scheduling - removes medicating as pain behaviour, reduces reliance on medication
• behaviour reinforcement - discourages sick-role behaviour, reduces the disability that accompanies chronic pain and increases the activity levels

Question 25

Name some other psychological pain control methods

Answer 25

• Biofeedback – provides biophysiological feedback to patient about some bodily process the patient is unware of
• Relaxation – systemic relaxation of the large muscle groups
• Hypnosis – relaxation and suggestion and distraction and altering the menaing of pain

Question 26

Name the centrally acting agents used for pain control

Answer 26

Antidepressants (tricyclics, e.g. amitriptylline), 5HT

Antipsychotics - works in similar way to antidepressants but often more sedating

Mood stabilisers - special circumstances

Question 27

How do you manage pain

Answer 27

• Aggressive pharmacotherapy optimisation (monitoring, increasing dose or switching)
• Weaning of opiates
• 12 week CBT programme
• Follow up – increase dose, switch, new CBT approaches