Mod 15 Pain and Nociception Flashcards
How is pain vital to human survival?`
- teaches us to avoid potentially harmful situations
- elicits protective withdrawal reflexes from noxious stimuli
- encourages to protect and rest injured parts of our body
What is nociception?
sensory nervous system’s process of encoding noxious stimuli
What is pain?
- perception (physical discomfort, hurt, or suffering) resulting from actual or potential tissue damage
- personal experience influenced by biological, psychological, and social factors
What is acute pain?
- result of tissue damage, with well defined onset and pathology
- protective function
What is chronic pain?
- no protective function and does not always need tissue pathology
What are the two types of acute pain?
- nociceptive
- neuropathic
What is nociceptive pain?
due to actual activation of nociceptors
What is neuropathic pain?
neurons have been sensitized to pain, still carry sensation of pain
How is pain unique to each person?
several factors (biological, psychological, social) can influence the perception of pain
Is nociceptor activation/firing necessary for pain?
not exactly
Is the life expectancy for patients with no pain sensation the same as those with?
no, tend to be shorter
What are the characteristics of nociceptors?
- “free” nerve ending
- A delta fibers (fast): mechanical and thermal
- C fibers (slow): chemical and polymodal
What is the nociception response?
A fibers: first/fast response, sharp and localized
C fibers: throbbing, aching dull pain sensation
What happens if you block A delta fibers?
loss of initial fast response of sharp and localized pain
What happens if you block C fibers?
loss of dull, poorly localized pain
What is the role of glutamate and neuropeptides?
glutamate: fast acting neurotransmitter (fast pain)
neuropeptide: slow acting, can enhance effect of glutamate
What is unique about nociception compared to other senses?
only human sense that becomes more sensitive with repeated exposure
What is the neospinothalmic component of the STT?
- a delta fibers
- mediates fast pain, temperature, and touch
- localized discriminative nature
What is the paleospinothalmic component of the of the STT?
- c fibers
- mediates slow pain
- more enduring, aching, intense pain with an affective nature
Where do primary afferents conveying nociceptive input synapse in the spinal cord?
dorsal horn
What do wide, dynamic range neurons respond to?
typically respond to nociceptive input but receive non-noxious input as well
What is affect?
emotional feeling, tone, or mood attached to a thought elicited by conditions and circumstances of internal and external environments
What is motivation?
state of need within us that arouses, maintains, and directs behavior toward a goal
What is acute pain?
- occurs as a result of tissue damage
- well defined onset
- protective in nature
What is chronic pain?
- outlasts time expected for tissue healing
- may occur with or without detectable tissue damage
- no longer serves a protective function
What are the characteristics of acute pain?
- nociceptive
- neuropathic
What are the characteristics of chronic pain?
- neuropathic
- nociplastic
How are nociceptive signals modulated?
- sensitization
- peripheral (primary hyperalgesia)
- central ( secondary hyperalgesia) - inhibition
- gate control
- descending systems of analgesia
What is peripheral sensitization?
increased sensitivity of receptors and primary afferents to noxious stimuli
What is primary hyperalgesia?
exaggerated sensitivity of a nociceptor to noxious stimuli
form of peripheral sensitization
What is central sensitization?
amplification of neural signaling within the CNS that elicits pain and hypersensitivity
What is secondary hyperalgesia?
exaggerated sensitivity in areas outside the zone of injury
form of central sensitization
What is allodynia?
ordinarily painless stimuli are experienced as pain
form of central sensitization
What is nociceptive pain?
pain that comes from actual or threatened damage to the non-neuronal tissue due to activation of nociceptors
What is neuropathic pain?
caused by a lesion or disease of the somatosensory nervous system
What is nociplastic pain?
pain coming from altered nociception despite no clear evidence of actual or threatened tissue damage
cause activation of peripheral nociceptors or evidence disease or lesion of somatosensory system
What is the assessment of nociceptive pain?
- clear proportionate mechanical natter to pain
- pain is localized to area of injury
- reproduction of pain with movement
What is the assessment of neuropathic pain?
- pain described as burning/shooting
- pain is associated with other neurological symptoms
- positive neurological findings
- pain provocation on palpation of relevant neural tissues
What is the assessment of nociceptive pain?
- pain is disproportionate to nature and extend of pathology
- non anatomical
- maladaptive psychosocial factors
- absence of signs of tissue injury/pathology
What is gate control theory?
pain signals can be interrupted in the substantia gelatinosa of spinal cord, acts as a “gate”
What is the gate control theory in simple terms?
activation of light touch A-beta fibers activate inhibitory interneurons in the spinal cord that shut off the nociceptor fiber transmission
- when you jam your finger and put pressure on it or hold it, it can make the injury less painful
A beta fibers block second order transmission of A delta and C fibers
How do PTs use gate control theory?
manual therapy, AROM, PROM, low grade joint mobilization
Is gate control theory temporary or permanent inhibition?
temporary
What is descending analgesia?
descending pain modulation system, projections from cortex to spinal cord to modulate pain
initiate release of endorphins: serotonin (raphe nuclei) and norepinephrine (locus coeruleus) to make pain not feel as bad
How do you manage pain from the periphery as a PT?
touch and massage
grade 1-2 joint mobilization
heat and cold
transcutaneous electrical nerve stimulation
What is exercise-induced analgesia?
release of beta endorphins from the pituitary and the hypothalamus enables analgesic effects by activating m-opioid receptors
What is phantom limb pain?
following amputation of limb surgically or accidentally, you feel pain and parathesias in the missing limb
How do you treat phantom limb pain?
surgical ablation, hypnosis, and rehab
What is thalamic syndrome in relation to pain?
- central post stroke pain
- intractable as pain generation is above major centers of pain modulation
- severe, burning, spontaneous paroxysmal pain
What is important about complex regional pain syndromes?
- post traumatic pain is disproportionate to the severity of the injury and accompanied by allodynia and automatic changes
- maladaptive plasticity throughout nervous system
- changes in cortical body representation
What happens in central sensitization?
- things that were not seen as painful are now painful (allodynia)
- things that are slightly painful are now super painful (hyperalgesia)
What is graded exercise?
physical activity that starts very slowly and gradually increases overtime
What is graded exposure?
process by which you slowly and progressively expose yourself to some form of stress, in order to make you less sensitive to that form of stress
What are the benefits of pain neuroscience education?
- pain ratings
- disability
- pain knowledge
- pain castrophization
- fear avoidance
Who benefits from pain neuroscience education?
- sensitized nervous system
- long lasting pain
- high levels of fear or fear avoidance
What are the drawbacks of pain neuroscience education?
- not viable intervention for pain and disability
- provides concerns regarding healthcare costs
- clinicians need to be trained
- long term effects not as significant as short term
What type of pain can PNE be used with?
nociplastic
What can use in addition with PNE?
- mobilization and manipulation
- soft tissue massage
- muscle and neural mobilization
- trunk stabilization
- circuit based aerobic exercise
- movement exercise
- dry needling
- usual PT care
What referred pain area is associated with the diaphragm?
c3-4
What referred pain area is associated with the heart?
t1-4
What referred pain area is associated with the gallbladder?
t7-8
What referred pain area is associated with the small intestine?
t9-10
What area of referred pain is associated with the large intestine?
t10 on right
What referred pain area is associated with the reproductive organs?
t10-12
What referred pain area is associated with the kidneys and ureters?
L1-2
