Neurophysiology of Pain Flashcards
The International association for study of pain definition
unpleasant sensory or emotional experience associated with, or resembling that associated with, actual or potential tissue damage
6 key notes of pain
1) pain is a personal experience
2) pain and nociception are different phenomena.
3) pain is learned through life experiences
4) pts report of pain should be respected
5) usually serves as an adaptive role but may have adverse effects
6) verbal description is only one of the several behaviors to express pain
biopsychosocial model of pain
- complex multifaceted phenomena
- addresses pain with social, biologic and psychological factors
biological factors of pain
- genetics
- physiology
- neurochemistry
- tissue health
social factors of pain
- SES
- Social
- Skepticism (due to negative feedback loops)
- operant
- social learning
- social support
psychological factors of pain
- perceived control of self-efficacy
- catastrophic thinking
- hyper vigilance
- depression
- anxiety
- anger
- can change the way we think of pain in the brain through spinothalmic offshoot to anterolateral tract
Guidlines for PTs using the biopsychosocial model
1) biological, physcial, psychological, social, and environmental factors are specific to each individual
2) pain must be addressed in a comprehensive, safe, ethical, and consistent manner using valid and reliable measuring tools.
3) comprehensive pain management should be underpinned by sound theoretical models and empirical evidence
4) PTs should be empathic and compassionate to pt in communication
IASP article 1
the right of all people to have access to pain management without discrimination
IASP article 2
the right of people in pain to have acknowledgement of their pain and to be informed about how it can be assessed and managed
IASP article 3
the right of all people with pain to have access to appropriate assessment and treatment of the pain by adequately trained health care professionals
factors that can lead to chronic pain
diet, sleep, stress, physical inactivity, sedentary behavior, smoking
chronic pain is a major health crisis
it affects more people then CVD, cancer and diabetes combined
delta fibers
- large in diameter
- myelinated
- high conduction velocity
- sharp and localized pain
- mechanical or pressure
- “prickly”
- Stabbing or shooting
C fibers
- unmyelinated
- dull pain
- diffuse pain and longer in duration
- pressing, aching, dull
- thermal, chemical, or mechanical
- referred pain from organs
Peripheral nerve distinction
- burning, tingling, pins and needles
- extremities
- follows peripheral nerve pattern
- Tinels sign (tapping) increases pain
- constant pain
muscle pain distinction
- localized
- palpation over muscle increases the pain
- tender, throbbing, and stiffness
- increase with lengthening or contracting muscle
- reduced pain at rest
normal pain processing pathway
1) stimulus from peripheral nerve
2) dorsal horn depolarization: Ca 2+ diffuse into neurons causing the release of glutamine and substance P
3) signal sent via the ascending tract to the brain is perceived as pain
4) the descending tract carries modulating impulsed back to dorsal horn (brains natural way from reducing pain)
acute pain
contributes to survival by protecting the tissue from further damage. Normal response to painful stimulation
adaptive pain
protect tissues and promotes healing
maladaptive pain
process representing as a disease and represents the pathological functioning of the nervous system
chronic pain
pain lasting longer then 3 months. Tissue is no linger in protective mode but has a maladaptive process. may involve neuro pathways
negative neuroplasticity
chronic pain the involves alternative neuro pathways
what is prostaglandin
substance that causes inflammation and pain to promote healing
Substance P: neuropeptide
- the first responder to stress or pain in the periphery. released by variety of cells (dorsal horn, mast cell, and blood)
- immediate and on going
- caused vasodilation and histamine release
- strongly correlated with NS pain
- associated with glutamate: facilitator of neurotransmission
what is CGRP
vasodilator released form sensory nerves
Substance P pain pathway
stimulas - nociceptor - release of substance P - dorsal root excitatory interneurons - reticular formation (increases alertness) - hypothalamus and the limbic system ( behavioral and emotional responses to pain) - thalamus (perception of pain)- somatosensory cortex (localization of pain)
allodynia
pain from a non painful stimuli
analgesia
absence of pain sensation
hyperalgesia
increased sensitivity to painful stimuli
sensitization
increased responsiveness of nociceptive neurons to their normal input, and/or recruitment of a response to normally sub threshold inputs
IASP classification of pain 3 types
1) nociceptive
- adaptive and “regular pain”
2) neuropathic
- damage to the NS
3) nociplastic
- Negative neuroplasticity