Pain & homeostasis Flashcards
what is an example of chronic central sensitization? what are the symptoms like?
- chronic whiplash patients
- usual upper body symptoms
what can be injected into whiplash patients?
- saline injections
where do you inject a whiplash patient?
- into infraspinatus and tibialis anterior
did the control subjects and whiplash patients have similar sensitivity?
- similar widespread sensitivity from lumbar nerve root pain due to MRI - confirmed disc herniation of 6-24 months duration
what is the strongest predictor of future lower back pain?
- previous experience of low back pain
what is the strongest predictor of future NP?
- previous experience of NP
what does more widespread pain lead to? (2)
- worse natural history and clinical outcomes
what follows a low back pain episode even if symptoms are absent?
- paraspinal sensitivity follows a low back pain episode
where do recurrences of low back pain usually occur?
- usually occur in the same location as previous episodes
where does processing occur?
- facilitation and inhibition occurs at multiple sites
what is the spinal cord involved in?
- sensory integration
what is the brainstem known as?
- gain control centres
what does the brain control? (2)
- perception
- response programs
what is antinociception?
- dampens the incoming pain signals through local and distal inhibitory pathways
what is pronociception?
- heightens body’s awareness to pain in an effort to reduce further potential tissue damage
what antinociceptive processes happen in the brain? (4)
- thalamic gate
- attention control
- deconditioning
- relearning
what pronociceptive processes happen in the brain? (3)
- reorganisation
- conditioning
- catastrophizing
what antinociceptive process happens in the brainstem?
- descending inhibition
what pronociceptive process happens in the brainstem?
- descending facilitation
what are the antinociceptive processes that occur in the spinal cord? (2)
- gate control
- long term depression
what are the pronociceptive processes that occur in the spinal cord? (2)
- central sensitization
- long term potentiation
what are the antinociceptive factors in nociceptors? (2)
- adaption
- fatigue
what is the pronociceptive process that occurs in the nociceptors?
- peripheral sensitisation
what increases the likelihood of co- occurrence?
- mirror image
what are the interference patterns found in co- occurrence of pain?
- facilitation and inhibition
what are the four components of homeostasis?
- variable quantity
- receptor
- control centre
- effector
what is an example of blood pressure homeostasis?
- blood pressure
- baroreceptors
- brain stem
- vessel diameter, HR, SV
what is the variable quantity of pain?
- threat
what is the receptor of pain?
- nociceptor
what are the control centres of pain?
- multiple CNS centres
what are the effectors of pain? (2)
- physiology
- behaviour
what is the mature organism model?
- looks at how the brain and nervous system receives input, processes and outputs pain signals and what affect this has on the body
what is pain perception equal to in the mature organism model?
- pain perception is equal to sensory dimension
what are the two factors that output alters in the mature organism model?
- altered behaviour
- altered physiology
what is the neuromatrix theory of pain?
- describes pain as a multidimensional experience generated by various influences
what structure does the neuromatrix model have?
- cyclical model
what are the three stages of the neuromatrix model?
- input
- process
- output
how do outputs become inputs in the neuromatrix model?
- happens via a feedback loop
what does the central nervous system do with inputs?
- central nervous system integrates many inputs
what is the central nervous system always on lookout for? (3)
threats including:
- danger
- damage
- infection
what does the central nervous system continually do?
- continually samples, consciously and unconsciously
how is information on the environment retrieved in the neuromatrix model?
- external
via sensory organs
how is information on tissue retrieved in the neuromatrix model?
- internal
- via interoceptive and humoral pathways
where does the brain sample from?
- samples from itself
how are past experiences built in the neuromatrix model?
- from previous injuries and adverse childhood experiences
what are the three dimensions of the neuromatrix model?
- sensory
- affective
- cognitive
what did processing in more detail show?
- multiple brain areas are activated
what are neurotags?
- networks of brain cells distributed across multiple brain areas work in synergy to produce outputs
what is the homeostatic region of the brain?
- hypothalamus
what system is needed?
- smart multisensory threat detection alarm action system
what does an alarm system always need?
- needs outputs
is pain an output?
- yes, pain is a protective output
how is the central nervous system involved in outputs? what does this increase?
- CNS co-ordinates outputs
- increases chances of survival
what can outputs be based on?
- predictive models
what is the predictive process?
- neuromatrix input
- process
- output model requires modification
are pain neurotags exclusive or sufficient for pain?
- pain neurotags are neither exclusive to nor sufficient for pain
what do output predictions provide?
- provide faster responses to aid survival
what are predictions later calibrated by?
- calibrated by sensory stimuli
- confirmed or negated
what does the cyclical prediction process involve?
- prediction (outputs)
- sensory input (initial trigger & later calibration)
what can happen to the brain predictions?
- they can be tricked
what are the two types of central nervous system outputs?
- physiological
- behavioural
what is the short term physiology of central nervous system outputs?
- normal and adaptive
what is the long term physiology of central nervous system outputs?
- abnormal and maladaptive physiology
do physiological outputs always include pain?
- no
- may or may not include perception of pain
what does pain demand in physiological outputs? what is the highest priority?
- pain demands attention
- cortical output of highest priority
what is reduced by physiological outputs? (2)
- cortical processing capacity
- decision making speed
what is increased by physiological outputs?
- cognitive error rate
what system is activated by physiological outputs?
- visuomotor systems
what axes and activity are altered due to physiological outputs?
- hypothalamus pituitary adrenal axes
- SNS activity
what activity is modified by physiological outputs?
- immune activity
what two systems are inhibited by physiological outputs?
- digestive system
- reproductive system
what are the 5 unpleasant innate protective mechanisms of physiological outputs?
- pain
- immune system
- anxiety
- fatigue
- low mood
what does physiological output of pain result in?
- chronic pain
what does physiological output of immune system result in? (2)
- allergies
- autoimmunity
what does physiological output of anxiety involve and result in?
- involves fear/ fright/ flight
- results in phobias
what does physiological output of fatigue involve and result in?
- involves rest and recuperation
- results in chronic fatigue
what does physiological output of fatigue involve and result in?
- involves rest and reflection
- can result in depression
what can happen to sensitivity due to physiological outputs?
- can increase or decrease
- can get stuck
what type of response is sensitization? what learning does it involve?
- learned response
- non associative learning
what are the two determinants of chronic central sensitization?
- magnitude (load) of nociception
- time (duration) of nociception
what interventions should be involved in sensitization? (2)
- learning
- training
what is habituation?
- diminishing of an innate response to a frequently repeated stimulus
how do you de-sensitize allergies?
- non associative learning following exposure to an allergen
- intervention involving learning/ training
- habituation following graded exposure to diluted allergen
- immunotherapy
how do you de-sensitize phobias?
- non associative learning following exposure to a trigger
- intervention involving learning/ training
- habituation following graded exposure to the trigger
how do you de-sensitize chronic pain?
- non associative learning following mechanical stimuli
- intervention involving training or learning
- habituation following mechanical stimuli
how do you de-sensitize chronic pain following traumatic injury?
- habituation via brain training e.g., graded motor imagery, left/ right discrimination, mirror therapy
what are the three short term behavioural outputs?
- communicative pain behaviours
- protective pain behaviours
- social response behaviours
what are the three types of communicative pain behaviours?
- visual distress
- verbal expression
- paraverbal pain expressions
what are some examples of visual distress communicative pain behaviours?
- grimacing
- wincing
- crying
what are some examples of verbal expressions communicative pain behaviours?
- pain words
- swearing
what are some examples of paraverbal pain expression communicative behaviour?
- screaming
- whimpering
- grunts
- sighs
- moans
what response does protective pain behaviour involve and why?
- flight or fight response
- ends painful experience
what does protective pain behaviours send? what is learned?
- sends clear warning to anybody nearby
- learned avoidance of pain repetition > decreased use of injured body point
what does social response behaviour involve?
- involves others providing support and care
what are long term maladaptive behavioural changes? what do they decrease?
- long term avoidance of movement
- fear of movement
- decrease chance of survival
what is the fear of movement called?
- kinesiophobia
what does the longer somebody with LBP is off work mean? what should they do instead?
- means the less likely they are to ever return to work
- LBP patients recover better staying at work even if they are still in pain
what is pain strongly related to? what is the shared variance?
- assumed to be strongly related to disability
- shared variance less than 10%
what two models can be used when disability = pain?
- ICF framework
- Biopsychosocial model
why was there an exponential rise in work incapacity over the last quarter of the 20th century?
- due to low back pain
- psychological and social factors were believed to be associayed with this
what consequence does back pain have for society?
- work incapacity has an economic burden
how do you deal with behavioural outputs?
- change thoughts and feelings via CBT approach
what should you target when dealing with behavioural outputs? (2)
- target cognitive - evaluation and motivational affective inputs
describe the CBT approach
- reduce threats
- reduce emotional components
- change context
- simple messages can be useful
what are the three factors that CBT involve?
- behaviour
- feelings
- thoughts
what other treatment can be used for behavioural aspects other than CBT?
- cognitive functional therapy
what three factors does cognitive functional therapy involve?
- making sense of pain
- lifestyle change
- exposure with control
