PBL 2 - Aches and Pains

Question 1

What is inflammatory, acute pain caused by?

Answer 1

Acute nociceptive pain due to muscular strain or other soft tissue injury

Question 2

What pain travels down his leg?

Answer 2

Radicular

Question 3

Define allodynia

Answer 3

Noxious sensation to non-painful stimuli

Question 4

What is hyperalgesia?

Answer 4

Increased noxious perception to noxious stimulus

Question 5

What is secondary hyperalgesia?

Answer 5

Hyperalgesia occurring outside the area of injury

Question 6

What is peripheral sensitisation?

Answer 6

Increased sensitivity to afferent stimuli due to nerve and tissue injury

Question 7

What inflammatory mediators are response for peripheral sensitisation?

Answer 7

Phospholipase A2
COX 1 + COX 2
Prostaglandins

Question 8

How does phospholipase A2 cause sensitivity?

Answer 8

Releases arachidonic acid from cell membranes following injury

Question 9

What do COX 1 and COX 2 do?

Answer 9

Uses arachidonic acid as a substrate for prostaglandin synthesis

Question 10

What do prostaglandins do?

Answer 10

Affect ion channels

Question 11

How do affected ion channels cause peripheral sensitisation?

Answer 11

Increase Na+ channel opening and increase in receptor presence
Also closing K+ channels reducing activation threshold and increasing responsiveness of nociceptors

Question 12

How does central sensitisation occur?

Answer 12

Prolonged nociceptor input on dorsal horn

Question 13

What do nociceptive afferents release in central sensitisation?

Answer 13

Glutamate and peptides

Question 14

What do glutamate and peptides work on in central sensitisation?

Answer 14

NMDA

AMPA

Question 15

What is gate theory?

Answer 15

Idea that thalamus and amygdala can prevent painful stimuli from occuring

Question 16

Where do projections come from in gate theory?

Answer 16

Raphe nucleus

Question 17

What do projections from raphe nucleus activate?

Answer 17

Inhibitory interneurones in laminae II

Question 18

What do inhibitory interneurones in laminae II secrete?

Answer 18

GABA

ENK

Question 19

What is the fast pain pathway also known as?

Answer 19

Neo-spinothalamic pathway

Question 20

Which nociceptor is responsible for fast pain?

Answer 20

A delta

Question 21

Where do A delta fibres synapse?

Answer 21

Laminae V

Question 22

Where do A delta fibres decussate?

Answer 22

Spinal cord level

Question 23

Where do A delta fibres travel?

Answer 23

Spinothalamic tract to ventral posterior lateral thalamus

Question 24

Where does A delta fibres project to after ventral posterior lateral thalamus?

Answer 24

Somatosensory cortex 1 + 2 allowing for localisation and discrimination of pain

Question 25

What is the slow pain pathway?

Answer 25

Paleo=spinothalamic pathway

Question 26

What fibres are responsible for slow pain?

Answer 26

C fibres

Question 27

Where do C fibres synapse?

Answer 27

laminae I + II

Question 28

Where do C fibres decussate?

Answer 28

Spinal cord

Question 29

Where do C fibres synapse?

Answer 29

Medial and posterior thalamus

Question 30

Where do C fibres travel up?

Answer 30

Lateral STT

Question 31

Where do C fibres travel to after thalamus?

Answer 31

Project to anterior cingulate cortex + rostral insula

Question 32

What is the paleo-spinothalamic pathway for?

Answer 32

Emotional aspect of pain

Question 33

Why does the guy have pain?

Answer 33

Slipped disc at L4/L5

Question 34

What nerve is compressed in the guy?

Answer 34

Sciatic nerve dorsal root ganglion

Question 35

How is neuropathic pain different to nociceptive pain?

Answer 35

Described as burning or electric shock

Question 36

What is the analgesic ladder?

Answer 36

Non opioid Weak opioid Strong opioid

Question 37

How does paracetamol work?

Answer 37

Inhibits COX 2 to prevent prostaglandin formation

Question 38

Why does paracetamol not work in the scenario?

Answer 38

There is the presence of peroxides which are abundant during inflammation which causes the pathway to be inefficient

Question 39

What does the metabolite of paracetamol do?

Answer 39

Inhibits reuptake of endogenous cannabinoids, increasing the effect of analgesia

Question 40

What does ibuprofen do?

Answer 40

NSAID which inhibits COX and COX2

Question 41

How does inhibiting COX and COX2 decrease pain?

Answer 41

Prevents prostaglandin formation and recruitments of leucocytes

Question 42

What are side effects associated with COX 1?

Answer 42

GI bleeds Peptic ulcers Nausea Constipation

Question 43

What does diclofenac do?

Answer 43

NSAID which inhibits prostaglandin formation

Question 44

How does diclofenac work?

Answer 44

Inhibits COX 2 with longer activity than ibuprofen

Question 45

What are side effects of diclofenac?

Answer 45

Increased risk of heart attack and stroke | Hypertension

Question 46

What is tramadol

Answer 46

Atypical opioid which is a Mu receptor agonist

Question 47

What else is tramadol?

Answer 47

5-HT and noradrenaline reuptake inhibitor

Question 48

Side effects of tramadol?

Answer 48

Seizures Dry mouth Constipation Headaches

Question 49

What does morphine do?

Answer 49

Activates mu opioid receptors (MOR)

Question 50

How does morphine work?

Answer 50

Causes neuronal inhibition by reducing excitability (Increasing K+ conductance) and inhibit NT release (decrease Ca2+ influx)

Question 51

What does morphine activate?

Answer 51

Descending inhibitory pathways that arise from periaqueductal gray (PAG) which inhibits the spinal cord

Question 52

What are side effects of opioids (morphine)?

Answer 52

``` Constipation Nausea Psychosis Drowsiness Respiratory depression ```

Question 53

What is amitriptyline?

Answer 53

TCA antidepressant

Question 54

What does amitriptyline do?

Answer 54

Blocks serotonin and noradrenaline reuptake (as well as Na+ and Ca2+ channels)

Question 55

What are side effects of amitriptyline?

Answer 55

``` Dizziness Drowsiness Dry mouth Headache Weight gain ```

Question 56

What is pregabalin?

Answer 56

Anticonvulsant medication used in epilepsy

Question 57

How does pregabalin work?

Answer 57

GABA analogue (works like GABA) which acts on A2 delta subunit of Ca2+ channels

Question 58

What does Pregabalin work like GABA analogue?

Answer 58

As A2 Delta subunits of Ca2+ channels are increased in neuropathic pain so drug binding reduces Ca2+ entry to inhibit NT release

Question 59

What are side effects of pregabalin?

Answer 59

Drowsiness Dizziness Blurred vision Ataxia

Question 60

What is acupuncture a form of?

Answer 60

Diffuse noxious inhibitory control (DNIC)

Question 61

What is a DNIC?

Answer 61

Where pain in one part of the body reduces pain in other parts of the body

Question 62

What is activated when pins are inserted in acupuncture?

Answer 62

A-delta | PAG

Question 63

What do A-Delta and PAG do in acupuncture once stimulated?

Answer 63

Activates descending inhibitory pathways to control nociception

Question 64

What causes analgesia in acupuncture?

Answer 64

Laminae II inhibitory interneurones

Question 65

What fibres are activated in physiotherapy?

Answer 65

A-Beta fibres with non noxious stimuli

Question 66

What do A-Beta fibres activate in physiotherapy?

Answer 66

Inhibitory neurones in dorsal horn

Question 67

What happens when inhibitory neurones in dorsal horn are activated?

Answer 67

Inhibited C fibre transmissions cause analgesia

Question 68

How long should pain get better with physiotherapy?

Answer 68

3-6 weeks

Question 69

What may have happened to damaged muscle to cause physiotherapy to work?

Answer 69

Shortened and atrophied so muscle needs to be loosened and stretched which increases blood flow and decreases inflammation

Question 70

What will help prevent repeated injury?

Answer 70

Improving strength and maintaining good posture

Question 71

What should be used in conjunction with physiotherapy?

Answer 71

Ice and heat treatments to prevent scar tissue degradation