Test 2 Flashcards

Question

Biopsychosocial Model

Answer 1

Biological • Age, Gender, Genetics • Physiologic Reactions • Tissue Health Psychological •Menal Meat • Emotional Health Expectations Sociological • Interpersona Relationships • Social Support Onatic • Socioeconomics

Answer 2

Lots of variability in what makes pain differences- variability= heritability Higly influenced by environment

Answer 3

Inbred mice are brother-sister repeated matings (>20 generations).= genetic clones Test inbred mouse strains on different pain assays. Variability in pain sensitivity between strains is genetic. Variability within strain is environment and susceptibility to develop chronic conditions highly linked to variation in alleles

Answer 4

Women- more susceptible to pain and more sensitive Gout and back pain condition – males get it more Men less likely to get help Female have greater pain sensitivity

Answer 5

Did cold pressor and had opposite or same sex experimente- female rate higher in both cases Men- opposite sex- decrease pain rating

Answer 6

Hormone levels are an obvious contributor Many ligands, receptors and cell types involved Women report less chronic pain during pregnancy Upregulation of opioid receptors, decrease in Th1:Th2 ratio Females respond quicker- inc sensitivity Ovarextomy- remove ovaries- dec pain sensitivity Female sex hormones- inc sensitivity When pregnant- change in immune system Decreases tH1 cell ratio- decreases the immune response and decreases inflammation Inc th2 Microglia- in the cns- tag the invaders and try to get rid of them have neurons and glial cells- f Astroglial- support Pain activates microglial- in male- chronic pain reversed by inhibiting hese cells In female- don’t matter Block hyperexcitability- reverse pain in both sexes In late pregnancy- no allodynia Reverse microglial- reverse in male and female(in pregnancy)

Answer 7

If for example fire comes near the foot, minute particles of this fire, which you know move at great velocity, have the power to set in motion the spot of skin on the foot which they touch, and by this means pulling on the delicate thread which is attached to the spot of the skin, they open up at the same instant the pore against which the delicate thread ends, just as by pulling on one end of a rope makes to strike at the same instant a bell which hangs at the end.” Descartes Signal sent to brain

Answer 8

Different receptors in skin for different sensations Meissner corpuscle- touch flutter Pacinian corpuscle vibration Ruffinis corpuscle stretch Merkels disks touch, pressure Pain nerve endings - nociception)- responds to noxious stimulus

Answer 9

Nociceptors are special receptors that respond only to noxious stimuli and generate nerve impulses which the brain interprets as “pain” Free nerve endings Tissue damage Tissue damage results in cells breaing, releasing toxins into the system Prostoglandin- ege2 Causes swelling/ inflammation White blood celss and mast cells go here and release chemicals- start to activate specific recpetors on free nerve ending- Causes an action potential- sometimes go to cell body,- neuron terminates in spinal cord- releasing substance p or glutamate but goes all ober the place- can reach other free nerve endings to release more chemicals– axon reflux- releases substance p- causes inflammation, is excitatory, causes vasodilation- spreds wuicker and releases more blood cells- sesntive nociocpetord

Answer 10

Dendrites found on skin, in bone, muscle- dendrites= free nerve endings and have long axon- periphial Cell body- outside if spinal cord- in dorsal root ganglia Multipolar- CNS Unipolar neurons have one process from the cell body, an axon. It branches to connect to receptors and the spinal cord or brain. Unipolar neurons are most of the body's sensory neurons. The dendrites are found at the receptor and the axon leads to the spinal cord or brain.

Answer 11

Aa- proprioception, skeletal muscle, gives body space awarness feedback Ab- connected to mechanorepetors- touch – attaches to corpuscles and transmit sensory info Ad- convey pain and temp info- nocioceptors C- pain ,temp, itch, sweating – unmyelinated Larger fobre and more myelin- faster

Answer 12

Packaged into sheet- have many axons- blood supply Axon collection- endonerium Nocioceptors packaged together to transmit info

Answer 13

Bump knee- first notice sharp pain- very quick- Ad fibres Have lasting throbbing- C

Answer 14

DRG – dorsal root ganglion – cells bodies of sensory neurons Sensory neurons – axons sent to periphery and to dorsal horn of spinal cord All sensory info when reaches close to spinal nerve- eneters through dorsal root of spinal nerve Have spinal roots- send projection into dorsal spinal cord Also have ventral part- motor info goes out this way to leave spinal cord But sensory and motor info- packaged in same spinal nerve

Answer 15

Neuropeptides Paracrine- released and work on other cells to activate them and autocrine actions- works on cell released from Peptidergic- contains neuropeptide CGRP, substance p vs. non-peptidergic- use glutuamte Substance P Released from sensory nerve terminals (C fibers) upon injury or infection – causes inflammatory response Mediates actions through the neurokinin 1 (NK1) receptor NK1 expressed by endothelial cells, keratinocytes, spinal neurons and glial cells Can be released antidromically- opposite direction then normal – from dendrites where it contributes to plasma extravasation, mast cell degranulation and neurogenic inflammation Activation of NK1 by substance P causes receptor to become internalized and upregulated. Causes nk1- to make nucleus make more transporters, inc sensitivity for substance p Mast cells release content- paracrine Found in DRG cells, can be releases into dorsal spinal cord to transmit and continue pain signal Cells release chemicals into spinal cord- when cut yourself etc- mostly neuropeptides(transmit nerve signal)- Substance P

Answer 16

Expressed by neurons in the peripheral and central nervous system Most abundantly expressed by subset of nociceptors in the dorsal root ganglion (DRG) and trigeminal ganglion- facial pain. Not found in spinal neuron cell bodies.- released from DRG Importantly involved in vasodilation, resulting in swelling, increased blood flow and recruitment of inflammatory cells to area of injury. CGRP receptor not found in cells that express CGRP- doesn’t act in autocrine fashion CGRP is released in the spinal cord of rats with chronic injury- injure nerve then measure levels= higher

Answer 17

What is “afferent”- toward vs. “efferent”?- away What is “medial” towards middle versus “lateral”?- to side What is “ipsilateral”- same side vs. contralateral”? Opposite sides Rostral- towards head] Caudal- towards tail Dorsal towards back -above Ventral towards tummy – below Shingles lays dormant in DRG- reactivate the virus, expresses in the body where innervated by DRG Upper thigh- l2, l3 Have as many drg as vertebrae- at every level of vertebrae Shingles reactivated- upper shoulder- innervated by c3 and 4- where drg virus is reactivated Dermatome map

Answer 18

Meninges- membrane surrounding brain and spinal cord Grey- cell bodies and neurons v s. white matter- tract system Vertebral segments S pinal cord encased in bone Affererent comes in through drg activates neuron and sends ap along white matter

Answer 19

Hormone levels are an obvious contributor Many ligands, receptors and cell types involved Women report less chronic pain during pregnancy Upregulation of opioid receptors, decrease in Th1:Th2 ratio Females respond quicker- inc sensitivity Ovarextomy- remove ovaries- dec pain sensitivity Female sex hormones- inc sensitivity When pregnant- change in immune system Decreases tH1 cell ratio- decreases the immune response and decreases inflammation Inc th2 Microglia- in the cns- tag the invaders and try to get rid of them have neurons and glial cells- f Astroglial- support Pain activates microglial- in male- chronic pain reversed by inhibiting hese cells In female- don’t matter Block hyperexcitability- reverse pain in both sexes In late pregnancy- no allodynia Reverse microglial- reverse in male and female(in pregnancy)

Answer 20

Biological variable- contributes to pain development and sensitivity First graph- X axis- age groups Open box= population, filled= pain centre Don’t see young ppl getting chronic pain treatment During middle age- have more getting treatment although population is less Shows you population prevelance vs those getting treated at pain centre As age decline in both categories Pain gets worse up until your middle years then goes back down As age may get more sensitive but have more pain experience, same pain experience may not lead you to get treatmenet Xould have a biological relationship between age and pain reduction but could be psychological- expecting to hurt more so don’t go to clinic Rat pain- trying to avoid pain from heated surface- rat can escape and go into other area 8- 16 months- have quickest escape response- more sensitive to pain As age escpae duration becomes longer As we age may be greatwe insensitivity to pain Older rats may just be slower

Answer 21

Environemt modulates recovery from environemnt Rats went under surgery- CCI- nerve injury- SNI and CCI- tie suture around nerve to constrict it- sensitivity develops Can measure recovery Had regukar vs enriched environment In enriched- recovery is faster Could be related to exercise as well Environment matters

Answer 22

Social environment is important for persistence and recovery of pain and chance to get chronic pain Looked at married couples- one with chronic pain Wanted to understand social development and how it affects development of chronic pain Used wimpy- measures spousal responses and social dynamics- in pain patient Had spouse write diary- solicitiousness- led to chronic pain Someone whos very supporting and kind- in both diary and spouse- led to inc pain More caring spouse= more pain Spouse is reinforcing pain behaviour To improve pain- spouse can engage in distraction techniques- distract from pain

Answer 23

Empathu studied with pain as output measure Feel empathy, pain sensitivity changes Activates same pain responses when watching someone you love experience pain Enhancing pain sensitivity Meausured thermal responses- when it hurts and how much Did this while watching video Positive group- watch empathetic inducing video Negative group- inducing lack of empathy/ disgust In positive group- more perceived intensity- sensitivity and unpleasentness- perception of pain Positive group felt more empathy

Answer 24

Can have mice watch other mice going through pain Inject acetic acid into mice- does writhe response extend and cotorse torso If take both mice and inject both- writhing goes up- pccurs more This only occurs if the mice are familiar Stress blocks empathy- when meet stranger a little stressed

Answer 25

Henry Beecher discovered the placebo effect as a medic in World War II. After running out of pain-killing morphine, he replaced it with a simple saline solution but continued telling the wounded soldiers it was morphine to calm them. To his surprise, almost half of the soldiers reported that the inert saline solution actually reduced or erased their pain. Beecher- world war 2 medic- civilian vs war pain narcotic request- stress induced analgesia Ran out of morphine- had saline and told them it was morphine Caused improvements in perceived pain

Answer 26

meta-analysis Binary- have it or don’t Continuous- on a spectrum Confidence interval cant pass 0 Placebo effect may be more pronounced for pain- but has more participants and trials Binary- harder to have placebo effect- yes or no, harder to show an improvement

Answer 27

Inert substance or treatment that activates endogenous body systems and brain networks- counteracts condition you have Expectation influences bodily response to treatment and anticipates outcomes- what you anticipate influences it, don’t believe in treatment- less likely to work Covert-Overt Paradigm Protocol where the patients are either informed about the drug effect or given it in a hidden way- tell patient youre giving them an effective drug- high pain reduction, don’t tell= no pain reduced Can be done in open context- informed patient and still work if participant believes in actual drug Patient expectation- causes more pain reduction= placebo effect What is the Placebo Effect? conditioning? Expectation- expectation to what will work? desire?- desire to get better natural history? (regression to the mean)- when it feels worse than before or different Conditioning- stick to same drug- know it works- history with medication- type,colour, size’ When have pain reduction- not all because of drug, part of it is due to placebo effect

Answer 28

Active treatment- drug- has an effect that causes outcome If have knowledge abt treatment- causes a non specific effect that influenceds the outcome Treating with placebo- want to remove active treatemnet- tell them itll do something- give them the knowledge Or give active treatment but don’t tell them abt the drug In this study- told remifentanil- improves pain and gets worse when stop administering Used VAS scale No expentancy- reduces pain a bit Have positive expectations- reduces pain even more Negative expectation- stopped it even if you didn’t- pain intensity goes close to baseline With expentancy- combined drug and placebo effect

Answer 29

subjectivity vs. objectivity of measure (pain or depression- more placebo effect vs. wound healing or Parkinson’s) the nature of the verbal suggestions (compare “It can be either a placebo or a painkiller” to “It is a powerful painkiller”) previous experience belief/expectation/desire of patient and clinician patient-clinician interaction (the “therapeutic context”) -“bedside manner” (enthusiasm, reassurance, empathy, communication) -white coats- positive effect -deep voices- greater placebo effect physical properties of placebo itself -sham surgery > i.v. placebo > big pill > small pill -expensive pill > cheap pill personality variables (esp. “ego-resiliency” and “agreeableness”) More invasive surgery= greater placebo effect

Answer 30

Placebo effect mediated by opiods- endogenous opioid system Follow pain intensity of open injection of saline- decreases pain sensitivity Administer drug in hidden fashion- over tume pain sesnitivty reverses to baseline- because of nonspecific opiod blocker

Answer 31

Placebo effect mediated by endogenous opiod system PAG, amgydala, Vpfc Activated in response to placebo and release endogenous opiods and dopamine to reduce pain but also generate experience of pain

Answer 32

Nocebo- negative expectations – makes things worse Driven by the fear, anxiety of pain

Answer 33

Mice tested for thermal thresholds using Hargreaves test. Mice injected with acetic acid and then placed in context for 30 min 24 hrs later mice returned to same context or different context Thermal thresholds measured using Hargreaves test. When mice returned to pain environment- have negative association that enhances pain sensitivity

Answer 34

Fear avoidance model Persistent pain  fear, avoidance and physical deconditioning Fear-avoidance model  pain may be chronically maintained through cognitive appraisals Avoidance of activity may act as negative reinforcement for the fear-avoidance cycle. Trauma PTSD is higher in chronic pain populations Higher pain at time of injury is associated with PTSD Chronic pain and PTSD  hypervigilance to threats Depression Chronic pain populations have a higher prevalence of depression ”Chicken and egg” problem; what’s the causal direction – both may be true Learned helplessness as a model to conceptualize depression in the context of chronic pain Catashprophizing- leads to more fear, more pain, more depression enhancing pain experience

Answer 35

Pain self-efficacy One’s belief in controlling events of situations Associated with lower perceived pain, reduced depression, improved physical function Considered a contrasting factor to catastrophizing High social component (positive expectations from your Dr.) Acceptance- better outcome Individual’s willingness to engage in valued goal-directed behaviour despite the pain Mental struggle is not evident in these people Focus on the positive (life events, social, hobbies). Psychology in treatment of chronic pain Interdisciplinary care is best approach Cognitive behavioral therapy educates patient on the biopsychosocial nature of pain to reinforce different thinking about pain conditions Acceptance and commitment therapy (ACT) and mindfulness improve protective factors and promote resilience Reduces the negative thoughts and feelings getting people to think differently about their pain Drugs alone wont work