Lecture 1: Introduction to pain

Question 1

What is a pain etiology?

Answer 1

The presumed cause of pain

Question 2

What is nociceptive pain?

Answer 2

• Caused by potentially harmful stimuli being detected by nociceptors around the body.
• No nervous system lesion or inflammation

Question 3

What is inflammatory pain?

Answer 3

• Causes active inflammation
• It is a spontaneous and stimuli-dependent pain
• It causes sensory amplification (the longer the pain is there the more painful it is)
• It is evoked by low and high intensity stimuli

Question 4

What is dysfunctional pain?

Answer 4

• Chronic pain that appears also when there is no stimuli
• Not known to be causing structural nervous system lesion or active peripheral inflammation
• Spontaneous and stimulus-dependent pain
• Sensory amplification
• Evoked by low and high intensity
• Present with lack of stimuli

Question 5

What is neuropathic pain?

Answer 5

• Often the result of a nervous system lesion or disease
• Marked neuroimmune response
• Spontaneous and stimulus dependent pain (sensory amplification, evoked by low and high intensity stimuli)

Question 6

What are the different possible pain locations?

Answer 6

• superficial
• deep
• visceral
• neuropathic
• phantom limb

Question 7

what is superficial pain?

Answer 7

Pain to the skin

Question 8

What is deep pain?

Answer 8

pain to muscles, joints, bones

Question 9

What is visceral pain?

Answer 9

It’s referred pain, you say it feels like it hurts somewhere (for example you feel like your tummy hurts but it’s actually your colon the stimuli)

Question 10

Where is neuropathic pain located?

Answer 10

Neuropathic pain is referred pain, but it is hard to know where the exact location of the stimuli is.

Question 11

Where is phantom limb pain located?

Answer 11

This is also a problem, the limb is not actually there so it is hard to know where the pain is located.

Question 12

What are the different symptoms of pain disorders?

Answer 12

• spontaneous pain
• evoked pain
• paresthesia/dysesthesia
• numbness
• paradoxical thermal sensations
• aftersensations

Question 13

What are the two types of spontaneous pain?

Answer 13

• continuous: the pain is always there

- paroxysmal: sometimes it’s there, sometimes it’s not.

Question 14

What are the 4 different possible evoked pain? (Also called pain hypersensitivity)

Answer 14

• The two types of hypersensitivity are allodynia and hyperalgesia, which can both be caused by thermal, mechanical, cold or vibration stimuli.
• evoked pain can be static or dynamic (stimuli stays in one place or moves)
• it can also be activity-evoked (ex by walking)

Question 15

What are paresthesia and dysesthesia?

Answer 15

They are both “funny feelings” but paresthesia is not necessarily unpleasant whereas dysesthesia is an unpleasant feeling.

Question 16

What is the problem with numbness?

Answer 16

Numbness is a symptom that you are in pain, and it can be a big problem because it’s unpleasant.

Question 17

What are paradoxical thermal sensations?

Answer 17

When a cold thing feels hot or the opposite

Question 18

What are aftersensations?

Answer 18

The sensations that stay after pain (for example after you get out of surgery)

Question 19

What is allodynia?

Answer 19

Allodynia is when you feel pain from a stimuli that usually wouldn’t be painful.
Usually not noxious but noxious at the moment of stimuli (for example a kind little tap on the back hurts when you have a sunburn)

Question 20

What is hyperalgesia?

Answer 20

Hyperalgesia is when you feel even more pain form a stimuli that would normally hurt also. (example: a big slap on a sunburn vs a big slap without sunburn)

Question 21

What is the difference between a sign and a symptom?

Answer 21

• A symptom is what the patient tells you he feels

- A sign is observed by a doctor during a physical examination.

Question 22

According to a study on squids, what would be the reason of the existence of chronic pain hypersensitivity?

Answer 22

If they anaesthetise the injured squid, they made it worse, because more of them died.
Pain was useful to the survival of the squid.
Conclusion: Maybe the purpose of the chronic pain is to remind you that you’re injured so you be careful.

Question 23

What prevalence of chronic pain did Elliott and Al find in their study?

Answer 23

• 50% of people experience chronic pain in a lifetime

- point prevalence: 20 to 25% of people have chronic pain right now.

Question 24

What is the difference between prevalence and incidence?

Answer 24

• prevalence: current total of a thing (talk about it to make something big)
• incidence: the new occurrences of a thing (talk about to minimize something)

Question 25

What is the prevalence of pain by sex and age?

Answer 25

- pain more common in women especially from middle age to old age - for migraine: there is no sex differences before puberty but there is after puberty

Question 26

What is the prevalence of pain by education level?

Answer 26

-more common in those with less education -Maybe they don't go to the doctor as much. Make less money, less able to afford medication. Under a lot of stress.

Question 27

What is the prevalence of pain by body part?

Answer 27

1. Lower back 2. Knee 3. Head

Question 28

What is a comorbidity?

Answer 28

- condition that appears with another condition | - Hard to know whether it's only correlation or if there is a causation and in what way that causation goes.

Question 29

What is the relation between chronic pain and suicide risk?

Answer 29

- 3 things you measure for suicide: thought, plan, attempt. - proportion of suicide always higher for people with chronic pain. - Women are more likely to be suicidal but men are a little more likely to attempt and actually succeed than women.

Question 30

What is the effect of chronic pain on lifespan?

Answer 30

20% of people with widespread pain died 14 years later, and only 10% of the people with no pain died. So there is excess mortality caused by pain.

Question 31

What did Aristotle believe about pain?

Answer 31

-pain is an emotion in the heart

Question 32

What did Galen believe about pain?

Answer 32

sensation in the brain

Question 33

What did Avicenna believe about pain?

Answer 33

pain is an independent sensation from touch and temperature

Question 34

What did Descartes believe about pain?

Answer 34

There exists a "pain pathway" from the body to the brain.

Question 35

What is theodicy?

Answer 35

Concept in modern philosophy. | If God is good, then why does God allow pain?

Question 36

What is utilitarianism?

Answer 36

Strain of philosophy that basically says that actions and morality should be decided on by virtue of pleasure and pain. You should maximize pleasure and minimize pain.

Question 37

What was admiral's Lord Nelson's view of the Mind-body problem and phantom limb pain?

Answer 37

phantom limb pain: alot of times when you loose a limb, you can still feel pain in the area of space where that limb used to be. According to Admiral Lord Nelson if you can still feel pain where the meat is gone, that is evidence for an existing soul, so the sensation lives in the mind and not in the body. Modern neuroscience would disagree with that again.

Question 38

What is the problem of other minds?

Answer 38

A person in front of you tells you they are in pain but you cannot fully believe them because you cannot feel this pain in the moment.

Question 39

What countries have the highest consumption of opioids (including medical use)?

Answer 39

- United States of America | - Canada

Question 40

What is a homeostatic emotion?

Answer 40

Analogy: thirst is a homeostatic emotion. | It compells you to do something.

Question 41

What are the adequate stimulus for each pain sensation?

Answer 41

Vision-->Photons Hearing-->Air molecules Pain--> alot of adequate stimulus for pain: heat (40celcius in hot tubs), cold (4 degrees), mechanical (knife of hammer), environmental irritants, pungent natural compounds (chili peppers), inflammatory peptides (inside the body) cut (broken cells are what is painful)

Question 42

What is the new definition of pain?

Answer 42

An unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage.

Question 43

What is somatosensation?

Answer 43

fancy word for touch

Question 44

How can you describe the thermal grill illusion?

Answer 44

-There is cool water in the blue tubes and warm water in the red tubes. If you put your hand around just a blue tube or just a red tube, you won't feel any pain. However, if you put your hand flat on all the tube you will feel a sensation of painful cold. -n this situation, there is no nociception, and yet there is pain. This happens in your brain.

Question 45

Why is there acute pain?

Answer 45

There is accute pain because: - it saves us from injuring ourselves worse than we're already. Prevent injury or further injury. - Pain is also a teaching signal. Its useful for the future. You know not to put your hand on a stove in the future.

Question 46

Why is there chronic pain?

Answer 46

chronic pain exists because: | -It's to inforce recuperation (resting and immobilization)