Pain Science Flashcards
what are the 2 criteria for a definition of pain
- pain can’t be replaced with the word fear and it still make sense (fear and pain are different things)
- definition needs to make sense for this patient
free nerve endings vs receptors in what they transmit
free nerve endings = send messages
receptors = send specific messages
what are primary afferents
first neurons to carry info toward the brain
what afferent fibers can have a specific receptor on the end
A-alpha
A-beta
A-delta
C
what is the speed of A-alpha afferent fibers and what is their function
highly myelinated
fastest fiber
proprioceptive functions from ms spindles and GTO
- ex: help you coordinate to stay upright
what is the speed of A-beta afferent fibers and what is their function
next fastest (after A-alpha)
decipher safe vs dangerous mechanical and thermal stim
what is the speed of A-delta afferent fibers and what is their function
slowest of myelinated primary afferents
detect hair follicle deflection
dangerous mechanical events
which of the primary afferent fibers are myelinated
A fibers
what is the speed of C afferent fibers and what is their function
unmyelinated, slow
detect safe vs dangerous mechanical, thermal, and chemical stim
what are free nerve endings
neuron doesn’t innervate specialized receptors
what is the optimal stimulus for free nerve endings
high intensity mechanical stim
- some may respond to temp
what is the advantage to the biology of free nerve endings
neuron itself is capable of generating action potentials rather than relying on a receptor at its terminal, such that the stim detection zone extends prox
what is a disadvantage to the biology of free nerve endings
can’t provide clear info ab the location of the stim
- pt will describe as general pain
what are the most prevalent and studied nociceptors
A-delta
C fibers
what stimuli do nociceptors respond to
stimuli that would damage tissue or would damage tissue if prolonged
what is the relationship to nociceptor activation and pain response
when nociceptors are activated doesn’t mach when a stimulus triggers pain
what is the relationship b/w nociceptor firing rate and tissue damage
nociceptor firing rate doesn’t match pain response
amt of damage to tissue doesn’t determine the firing rate of nociceptors
what is the relationship of quantity of nociceptors activated and pain response
number of nociceptors activated doesn’t match pain response
how does the duration of nociception firing relate to that of pain duration
the time course of pain doesn’t match the time course of nociceptor firing
ex: nociception happened and then dec w stim remaining constant –> pain cont to inc
what is the relationship between injury, nociception, and pain
the entire system is about protection and NOT about conveying an accurate indication of the state of tissues
where do primary nociceptive neurons terminate
dorsal horn of gray matter on spinal nociceptor
what is the pathway from the termination of primary nociceptive neurons on the dorsal horn of a spinal nociceptor
travels via periaquaductal gray and thalamus to brain
- brain assesses level of danger and need for action and will send either descending inhibitory or facilitatory to the spinal cord
when does the brain send the signal to create the output of pain
determined there is sufficient evidence of threat and potential tissue damage
context supports need for protection
what is the periaquaductal gray (PAG)
located base of brain
sum of all inputs from all sensory receptors throughout body
according to functional knowledge, when do we experience pain
DIMS > SIMS
DIMS = dangers in me
SIMS = safety in me
is pain a linear or emergent system
emergent
what does it mean that pain is an emergent system
pain arises spontaneously from many interacting micro parts
what do we have to provide if the patient has missing pieces of info
provide education to fill in the gaps
knowledge enrichment
what does it mean that a patient has a single grain misconception
learner’s pain knowledge held in grains that are not deeply anchored, or elaborated into a more mature concept
“its just old age”
“metal in my back can get hot and burn me”
what does it mean for a pt to have a sandcastle misconception
many concept neurotags are collaborating together
often multiple underlying misconceptions that are summarized in a single statement
“I am broken”
“I identify as busted lol”
what does it mean for a pt to have a sandstone misconception
learner’s misconceived knowledge is so coherent that its extremely difficult to change
- more deeply psych rooted beliefs
“its a massive disc herniation - four specialists have told me and I can see it on the MRI. you can’t fix that”
what is the goal when you are explaining pain to a patient
to create internal conflict for deep conceptual change
want them to see that it is their brain telling them they are in pain, not their elbow or knee
what is pain neuroscience education (PNE)
use of biopsychosocial model of pain to educate pt ab neurophys of pain thru relatable stories and metaphors
what should be your approach to pain (aka what are the pillars)
PNE +
goal setting, pacing, graded exposure
aerobic exercise
sleep hygiene
in pts who have given up on controlling their pain
goal setting through pacing and graded exposure
- break down their goal so it is achievable
what is the recommendation for aerobic exercise in pain
> 50% VO2max for >10min to elicit exercise induced hyperalgesia
-> endogenous opioids and neurochemical signaling
what is graded motor imagery
top-down method utilizing principles of neuroplasticity to facilitate improvement in central processing and organization of the sensorimotor cortex
who is graded motor imagery typically reserved for
people w highly sensitized systems
ex: CRPS, phantom limb, SCI, significant pain problem
what are components of graded motor imagery
laterality training
implicit/explicit motor imagery
- visualization
- guided mvmt
- localization training
- mirror therapy
are manual exercises top down or bottom up exercises
bottom up
what is the first step in a graded motor imagery program
laterality training
what is laterality training targetting
pts exhibiting central sensitization may have difficult time discerning L from R d/t central changes and rewiring
how does visualization as a component of implicit motor imagery work
implicit imagery starts away from sensory area and move towards it - consider homunculus organization
guide Qs about what a particular mvmt should feel like or if an object was touching the area
neuron firing pre-empts mvmt
why does visualization work
same neurons fire which create pain if they watch a mvmt that is painful for them as if they did it themselves
once implicit motor imagery is mastered, what is the next step
explicit motor imagery
what is explicit motor imagery
pt is guided through physical mvmt
- maybe initiate on uninvolved extremity and work back thru implicit mvmt questions as to what it feels like
how can point localization training be utilized
to bring awareness to a particular area of the body and to remap the brain’s awareness of the area
what can 2 point discrimination tell you
help you determine if there is central sensitization
if in more pain, less ability to discern
