2. Pain Models Flashcards
Describe the bidirectional processing of pain
Bottom up (Periphery --> brain) - Facilitation, inhibition and interneurons
Top down (Brain --> SC) -Person, beliefs, affect behavior
What are the networks with potential to affect the risk for chronic pain in the brain
- Reward network
- Descending pain modulatory system (DPMS)
- Areas also relevant to pain percept but that may not affect risk (Descending inhibitory and facilitatory influences)
What are the different pain receptors
A-delta (mechanical noxious stimuli
C-fibers= thermal and chemical noxious stimuli
Role of A-beta fibers
Detect non-noxious mechanical stimuli
Describe the biobehavioral model of pain
Many circles (from inside to out
- Tissue damage and nociception
- Perception
- Appraisal
- Pain behavior
- Social and external environment
What are the three methods of pain transmission in the nervous system
- Peripheral transmission
- Synaptic transmission
- Central transmission
What are the three fundemental concepts of pain
- nociception is not equal to pain
- acute pain is not equal to chronic pain
- pain=meaning
Define pain
Unpleasant sensory and emotional experience associated with actual tissue damage, or percieved tissue damage, or described in terms of such damage
Describe the common phenomenology associted with pain
Unpleasant sensory and emotional experience
What are the three different subtypes of pain
- Actual tissue damage
- Potential tissue damage
- Description (from patient) involving reference to tissue damage
T/F Activity induced in the nociceptor and nociceptive pathways by a noxious stimulus is not pain
t- it is always a psychological state even though pain is often associated with a physical cause
Describe the difference between nociceptive and neuropathic pain
Nociceptive pain
- Results from tissue damage that stimulates nociceptors
- Associated with acute tissue injury, dentistry, etc.
Neuropathic pain
- Disease state caused by damage to the nervous system
- Chronic pain conditions often the result of neuropathic pain
Be familiar with all the pain measurement scales
101- point numeric rating scale (NRS-101) 11-point Numeric rating scale (NRS-11) 11-point box scale (BS-11) 6-point behavioral rating scale (BRS-6) 4-point verbal rating scale (VRS-4) 4-point verbal rating scale-alt 5-point verbal rating scale
Look at the graph on slide 25 and understand the difference between someone who is more tolerant to stimuli and who is more tolerant to pain
ok
Which is more accurate- recording pain ratings throughout the day or end of the day
throughout the day
Define hyperalgesia and allodynia
Hyperalgesia
-Increased pain response to a noxious stimuli
Allodynia
-Pain from a non-noxious stimulus
Define Hyperesthesia and Dysesthesia
Hyperesthesia
- Increased sensitivity to stimulation
- (Like blowing on a sunburn)
Dysesthesia
- Evoked or spontaneous altered sensation
- I.e discomfort rather than pain
Describe the mechanism and characteristics of inflammatory pain
Mechanism
- Activation (caused by tissue damage and action of immune cells)
- Modification (structural changes)
- Modulation (peripheral and central sensitization)
Clinical manifestations
-Localized pain hypersensitivity (i.e heat hyperalgesia or allodynia + spontaneous pain)
Describe the mechanism and clinical manifestations of functional pain
Mechanism
- Central amplification
- Normal peripheral nerves and tissues
Clinical manifestation
-Generalized hypervigilence (Pain that is spontaneous and hypersensitive)
Describe the mechanism and clinical manifestations of nociceptive pain
Mechanism
-Activation (nociceptors) by chemical, mechanical, or thermal stimuli
Clinical Manifestations
- Pain linked to stimulus
- Autonomic response= withdrawl
Describe the mecahnism and clinical manifestations of neuropathic pain
Mechanism
- Activation
- Modification (structural changes– peripheral n. damage)
- Modulation (peripheral and central sensitization)
Clinical
- Localized pain hypersensitivity (i.e allodynia or hyperalgensia, sensory loss and paroxysms)
- Same as inflammatory pain
What are the two different kinds of neuropathic pain
central and peripheral
Central sensitization moves in what direction
SC –> brain
What analgesics are taken for
- Central sensitization
- Descending modulation
- Peripheral transduction
Central sensitization
- Anticonvulsants
- Opiods
- Ketamine
- Cannabinoids
Descending modulation
- Antidepressant (amitryptilline)
- Opiods
- Muscle relaxants
Peripheral transduction
- Topical agents
- Anti-inflammatory agents
- LA
Describe the process of modulation
Peripheral nociception –> Spinal cord integration –> Central processing –> Pain experience
What can be used to block peripheral nociception to spinal integration
local anesthetic
What types of drugs block movement of painful signals from the SC to the brain
- NSAIDs
- Opiods
- etc.
What are the clinical models of pain
Biomedical
- Pain is always a sign of tissue damage
- Linear relationship between tissue damage and pain
Psychoiatric model
- Pain without observable pathology is psychogenic
- Certain personality types are more prone
Biobehaviroal model
- Pain is multi-dimensional
- Not possible to separate the “physical” elements of pain from the “psychological” elements
what are the two different sub-therories of the transmission system based pain model
Specificity theory and pattern theory
The foundation of pattern theory is
summation theory
What is the gate control theory of pain
-Non-painful stimuli or cognitive activity can dampen or block painful sensations from reaching the brain
What is the significance of the gate control theory of pain
This is the physiological mechanism that explains how psychologic factors influence pain
The gate control theory of pain involves a gate that opens and closes to modulate pain, where is this gate located
spinal cord
Describe the path noxious signals take in traveling from the SC to the brain
SC
- C fibers and A-delta fibers and dorsal root ganglion
- Trigeminal subnucleus caudalis
Medulla
-Nucleus raphe magnus
Midbrain
-Periaqueductal grey matter
Forebrain
- Cerebral cortex
- Thalamus
What are the four models of brain processing
- Melzack: neuromatric theory
- Leknes and Tracey: Pain and pleasure
- Price: Sensory-affective dimensions
- Craig: homeostasis
All four models of pain processing agree with _ but differ on _
All agree with
-Inclusion of both sensory and affective dimensions
All differ
-Importance of peripheral and central mechanisms
