Lecture 1: Introduction to pain Flashcards
What is a pain etiology?
The presumed cause of pain
What is nociceptive pain?
- Caused by potentially harmful stimuli being detected by nociceptors around the body.
- No nervous system lesion or inflammation
What is inflammatory pain?
- 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
What is dysfunctional pain?
- 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
What is neuropathic pain?
- 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)
What are the different possible pain locations?
- superficial
- deep
- visceral
- neuropathic
- phantom limb
what is superficial pain?
Pain to the skin
What is deep pain?
pain to muscles, joints, bones
What is visceral pain?
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)
Where is neuropathic pain located?
Neuropathic pain is referred pain, but it is hard to know where the exact location of the stimuli is.
Where is phantom limb pain located?
This is also a problem, the limb is not actually there so it is hard to know where the pain is located.
What are the different symptoms of pain disorders?
- spontaneous pain
- evoked pain
- paresthesia/dysesthesia
- numbness
- paradoxical thermal sensations
- aftersensations
What are the two types of spontaneous pain?
- continuous: the pain is always there
- paroxysmal: sometimes it’s there, sometimes it’s not.
What are the 4 different possible evoked pain? (Also called pain hypersensitivity)
- 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)
What are paresthesia and dysesthesia?
They are both “funny feelings” but paresthesia is not necessarily unpleasant whereas dysesthesia is an unpleasant feeling.
What is the problem with numbness?
Numbness is a symptom that you are in pain, and it can be a big problem because it’s unpleasant.
What are paradoxical thermal sensations?
When a cold thing feels hot or the opposite
What are aftersensations?
The sensations that stay after pain (for example after you get out of surgery)
What is allodynia?
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)
What is hyperalgesia?
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)
What is the difference between a sign and a symptom?
- A symptom is what the patient tells you he feels
- A sign is observed by a doctor during a physical examination.
According to a study on squids, what would be the reason of the existence of chronic pain hypersensitivity?
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.
What prevalence of chronic pain did Elliott and Al find in their study?
- 50% of people experience chronic pain in a lifetime
- point prevalence: 20 to 25% of people have chronic pain right now.
What is the difference between prevalence and incidence?
- 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)
What is the prevalence of pain by sex and age?
- 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
What is the prevalence of pain by education level?
-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.
What is the prevalence of pain by body part?
- Lower back
- Knee
- Head
What is a comorbidity?
- 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.
What is the relation between chronic pain and suicide risk?
- 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.
What is the effect of chronic pain on lifespan?
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.
What did Aristotle believe about pain?
-pain is an emotion in the heart
What did Galen believe about pain?
sensation in the brain
What did Avicenna believe about pain?
pain is an independent sensation from touch and temperature
What did Descartes believe about pain?
There exists a “pain pathway” from the body to the brain.
What is theodicy?
Concept in modern philosophy.
If God is good, then why does God allow pain?
What is utilitarianism?
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.
What was admiral’s Lord Nelson’s view of the Mind-body problem and phantom limb pain?
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.
What is the problem of other minds?
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.
What countries have the highest consumption of opioids (including medical use)?
- United States of America
- Canada
What is a homeostatic emotion?
Analogy: thirst is a homeostatic emotion.
It compells you to do something.
What are the adequate stimulus for each pain sensation?
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)
What is the new definition of pain?
An unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage.
What is somatosensation?
fancy word for touch
How can you describe the thermal grill illusion?
-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.
Why is there acute pain?
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.
Why is there chronic pain?
chronic pain exists because:
-It’s to inforce recuperation (resting and immobilization)
