Central Sensitization Recognition and Treatment | Modern Manual Therapy Blog

Central Sensitization Recognition and Treatment

I'm back with more coverage on IFOMPT 2012! This time it's Dr. Jo Nijs and colleague's presentation on Central Sensitization (CS).

Mira Meeus, PhD in pain research

Hypersensitivity for all mechanical stimuli
  • allodynia
  • generalized hyperalgesia
  • referred pain
  • chronic pain
To differentially diagnose those with CS vs secondary hyperalgesia
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
In neuroplasticity, 2 things can happen
  • 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
Take home point for manual therapists
  • 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
2) changes in Top Down mechanisms
  • 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
A study showed that acetaminophen
  • increased peak performance in athletes
  • acted by sertonergic descending inhibitory pathways
3) Top Down - facilitory pathways
  • catastrophizing
  • kinesiophobia
  • somatization
  • stress
  • depression
These factors lead to cognitive/emotional pain sensitization
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
medical Dx that may have CS
  • 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
How to apply in daily practice
  • 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
  1. self efficacy
  2. depression
  3. pain catastophizing
  4. physical activity
Psychologic innocluation: a mindgame - study currently ongoing

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
Graded activity and exercise therapy
  • 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
  1. neuroscience education
  2. stress management
  3. activity self management
  4. graded activity
  5. recovery
There was so much information, I struggled to keep up with it all, and sorry this was not more of a narrative format. Hopefully if you have a neuroscience background, this provides some useful review and possible new information. If you do not, perhaps it will trigger your curiosity to find out more!


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