Pain

Question 1

What is pain?

Answer 1

an unpleasant sensory and emotional experience associated with actual or potential tissue damage

Question 2

Noxious

Answer 2

poisonous or harmful

Question 3

Hyperalgesia

Answer 3

heightened pain intensity as a response to noxious stimuli

Question 4

Analgesia

Answer 4

absence of pain or inability to feel pain

Question 5

Dysaesthesia

Answer 5

abnormal sensation felt when touched, caused by damage to peripheral nerves

Question 6

Paraesthesia

Answer 6

abnormal sensation with no apparent physical cause (e.g.: tingling, pricking, chilling, burning or numb sensation)

Question 7

Allodynia

Answer 7

innocuous (harmless) stimuli cause pain

Question 8

Hyperpathia

Answer 8

exaggerated responses to painful stimuli

Question 9

What is the physiology of pain?

Answer 9

1. An irritation or injury is detected in the peripheral nervous system by special nerves (nociceptors).
2. A nerve impulse is then generated, sending a pain impulse towards the CNS.
3. The message is received by the brain where the extent and significance of the irritation or injury is interpreted, and pain is sensed.

Question 10

What are nociceptors?

Answer 10

free nerve endings present in every tissue in the body except for the brain, which are activated by noxious stimuli

Question 11

What are examples of noxious stimuli?

Answer 11

• Thermal: severe heat or cold
• Mechanical: trauma, disease, injury, hypoxia, ulceration, infection, peripheral nerve damage, inflammation, ischaemia
• Chemical: histamine, kinins, prostaglandins, which are released due to tissue damage and inflammation

Question 12

How is line communication maintained?

Answer 12

by neurotransmitters (such as Substance P + Serotonin)

Question 13

What is the purpose of the descending pathway of pain?

Answer 13

to inhibit the sensation of pain

Question 14

How is pain sensation inhibited?

Answer 14

• Special neuropeptides with analgesic properties are released
• Which bind with opiate receptors, present throughout the CNS
• Block the action of neurotransmitter Substance P

Question 15

What are the 4 major categories of opiate receptor?

Answer 15

• mu (𝜇)
• 𝑘𝑎𝑝𝑝𝑎
• 𝑠𝑖𝑔𝑚𝑎
• delta.

Question 16

What are the (3) ascending tracts of the spinal cord transmission pathway?

Answer 16

• Spinothalamic
• Spinoreticular
• Dorsal column - medial lemniscal system

Question 17

What nerves are used to carry sensation from the head and oral cavity (trigeminal system)?

Answer 17

• Trigeminal nerve
• Facial nerve
• Glossopharyngeal nerve
• Vagus nerve

Question 18

What is peripheral sensitisation?

Answer 18

caused by multiple chemical mediators from nerve tissue damage and inflammatory response

Question 19

What is central sensitisation?

Answer 19

change in the sensitivity of the spinal cord synapses in the dorsal horn and upstream through the nervous system to the cortex

Question 20

What are some identifiable features of visceral pain?

Answer 20

• Pain diffuses and is poorly defined.
• Non mechanical pattern.
• Associated autonomic responses (e.g.: palpitations, nausea, etc).

Question 21

What is allodynia?

Answer 21

Pain due to a stimulus that doesn’t normally provoke pain.

Question 22

What is hyperalgesia?

Answer 22

Increased pain from a stimulus that normally provokes pain.

Question 23

What is central sensitisation?

Answer 23

Increased responsiveness of nociceptive neurons in the central nervous system to their normal or subthreshold afferent input.

Question 24

What is nociplastic pain?

Answer 24

Pain that arises from altered nociception despite no clear evidence of actual or threatened tissue damage causing the activation of peripheral nociceptors or evidence for disease or lesion of the somatosensory system causing the pain.

Question 25

Why do we not feel pain all the time?

Answer 25

- When the messages reach the spinal cord there is another gateway neurone. - This second gateway neurone also needs stimulating to pass on the ‘danger’ response to the brain. - However, the brain can block these messages from ascending. - The brain decides whether to let messages through and once through what they mean and how best to deal with the information.

Question 26

What is a normal pain response?

Answer 26

- Unpleasant sensation associated with actual or potential harm - Caused by stimulation to mechanical, chemical and thermal receptors. - Receptors are stimulated and ion channels open. - Positive ions enter the neurone if a threshold reached - action potentials created. - The action potential travels along the nerve to the spinal cord.

Question 27

What is the role of a physio in pain management?

Answer 27

- Assessment - Treatment and needed - Red flag assessment - Pain education / demystifying pain - Goal setting - Encourage self management - Onwards referral to pain specialist

Question 28

Describe a pain assessment.

Answer 28

- Subjective ratings scales: VAS, NRS, faces pain scales - Objective measures: McGill pain questionnaire, Pain beliefs and attitudes inventory, EQ-5D - Visual observations: pain behaviours, communication changes - Physiological responses: HR, BP, sweating, colour

Question 29

What factors affect pain?

Answer 29

- Anatomy / pathology - Mood - Sleep - Stress - Environment - Lifestyle eg work - Upbringing / childhood - Past experiences - Friends / family reactions

Question 30

What may we offer our patients advice on?

Answer 30

- Pain management - Pain education - Pacing - Postural advice - Workstation advice - Manual handling - General activity and exercise - Pathology education