Mira Meeus, PhD in pain research
Hypersensitivity for all mechanical stimuli
- allodynia
- generalized hyperalgesia
- referred pain
- chronic pain
CS normally has hypersensitvity to
- light
- touch
- noise
- pesticides
- mechanical pressure
- has widespread, non segmentally related Sx
- PPT thresholds are higher on one side versus the other
The following are also found in individiuals with CS
- fatigue
- sleep disorders
- habituation
- sensitization
- prolonged/repeated stimulation or strong stimulation will lead to sensitization
- more receptors are found in CS states
- ion channels remain open longer - thus transmission leading to pain occur more often
- if a nociceptive stimulation is applied once every 5 seconds or faster, C fibers cannot depolarize fully
- this leads to increased pain sensitivity
1) This is called Wind-Up or temporal summation of pain
- wind up occurs at the synaptic cleft of dorsal horn
- this is a result of excessive concentration of glutamate in the synaptic cleft with excessive stim or prolonged stim
- this further causes
- dorsal horn hyperexciteability
- allodynia
- hyperalgesia
- widespread pain
- be careful of
- the frequency of stimuli
- intensity of stimuli
- NSAIDs
- may reduce peripheral input might, possibly mediatint c-fibers
- NMDA antagonists (katemine)
- has an anti-allodynia and antihyperalgesia effect -> analgesia
- but non-specific blocking - may block learning, tolerance, associations
- increases analgesic effects
- but decreases tolerance and may cause dependence
- inhibitory substances - serotonin, opioids, etc
- in experimental block or lesions of pathways
- pain inhibition fails causing expansion of receptive fields leading to
- hypersensitivity
- faster wind-up
- pain inhibition is mediated by focus on relevant stimuli
- patient worried about a skinned knee vs other foot in fire
- the increased threat can inhibit via top down mechanisms
- could be caused by stress response
- short term stress response leads to release of epinephrine and norepinephrine
- long term response releases cortisol
- patients in chronic pain
- their inhibitory mechanisms were not working properly
- this is why exercise may exacerbate Sx
- control group had increased pain threshold
- CFS group had decreased pain threshold
- these results were also reproduced with whiplash associated disorder (WAD)
- pts may have an accumulation of pain stimuli (cold pack and pressure)
- diffuse noxious inhibitory control
- this is found in
- CFS
- FM
- WAD
- increased peak performance in athletes
- acted by sertonergic descending inhibitory pathways
- catastrophizing
- kinesiophobia
- somatization
- stress
- depression
catastrophizing - prediction of pain with 20% greater intensity for CFS
There is over activity of various regions of the brain with exercise, even when not painful for chronic pain pts --> psychosocial
The studies I am referring to can be found here.
Back to Dr. Jo Nijs
Recognition of CS in manual therapy practice
CS is not present in all chronic pain conditions
- important to recognize
- not everyone needs the pain science education if they are not centrally sensitized
- they may just have chronic (duration) pain
- sub(acute) musculoskeletal pain does not exclude the possibility of early sensitization
- fibromyalgia - 100% have CN sens
- chronic WAD
- chronic LBP - majority do not, but a subgroup does
- TMD
- myofascial pain syndromes
- OA - again, most do not, but it is possible
- education
- pamphlet,
- should be read 2-3 times, 60% forget your education within a few days
- pain and other Sx are unreliable messages as to the "damage"
4 main predictors/mediators of positive outcomes
- self efficacy
- depression
- pain catastophizing
- physical activity
expose someone to weakened counterarguments triggering a process of counterarguing
"this injury is caused by a muscle"
"your neck is preventing your from choosing something to wear tomorrow"
"on this earth, this isn't a single Tx that can ameliorate this condition"
"the upcoming 2 weeks, you do not have one positive thing to look forward to"
It works as a kind of innoculation, as in a graded exposure to catastrophizing that makes them almost realize the nature of their beliefs. Sounds mean, but effective according to Jo!
Manual Therapy
- hands on manual therapy in short term good Tx for CS, activates pain inhibitory pathways
- no studies show the relief lasts longer than 30-40 minutes
- bottom-up sensitization?
- does it strengthen pts biomedical beliefs?
- a combo of MT and neuro ed may only have pt coming back for the "magic bullet"
- Jo rarely combines both b/c pt will want MT more
- stress management important
- will increase inhibitory mechanisms of the brain
- acceptance therapy
- mindfulness
- both also activate the brain's inhibitory mechanisms
- more appropriate in the later stage, when it is more convenient to retrain dysfunctional neuromuscular control
- pain contingent faciliates the pain matrix
- time contingent with appropriate functional baselines, for goal setting, do not use pain as a goal
- careful with isometric exercise
- may accelerate central pain mechanisms
- careful with eccentric mm contractions
- may activate some inflammatory responses
- exercise and activity pacing
- multiple recovery periods within and following exercise sessions are important
The MT's Program Steps
- neuroscience education
- stress management
- activity self management
- graded activity
- recovery
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