Translate

Friday, March 7, 2014

Recognition of central sensitization in patients with musculoskeletal pain: application of pain neurophysiology in manual therapy practice.

Nijs J, Van Houdenhove B, Oostendrop RAB. Manual Therapy 2010 15:135-141.
Pelvic PT distance journal club 3/5/14
Beth Shelly PT, DPT, WCS, BCB PMD

Mechanism based clinical guidelines using medical diagnosis and history, clinical examination

·         Primary hyperalgesia - acute pain - several days - sensitization of the nociceptors to protect from further damage - local phenomenon
·         Secondary hyperalgesia - chronic pain -  increased responsiveness of dorsal horn neurons in the spinal segments of the primary nociceptors - central sensitization

Central sensitization (CS) - defined by Meyer 1995 - "an augmentation of responsiveness of central neurons to input from unimodal and polymodal receptors."
·         Altered sensory processing in the brain
·         Impaired descending inhibition of pain
·         Overactive ascending pain facilitatory pathways
·         Temporal summation of secondary pain = wind up
·         Long term enhancement of synapses in some areas of the brain
·         Net result
o   Augmented nociceptive signal
o   Increase responsiveness to a variety of peripheral stimuli
o   Decrease tolerance of senses

Figure 2 gives decision tree  

1. Medical diagnosis - it is not possible to label CS only be the medial diagnosis.   Fibromyalgia and chronic fatigue syndrome most often include CS.  Other diagnosis like chronic LBP, chronic whiplash, TMJ, MF pain, OA, RA, chronic HA and IBS may have CS components.  Presence of these diagnosis should alter PT to look for other indications of CS

2. History taking
·         Generalized increased responsiveness and decreased tolerance of a variety of stimuli - 2 or 3 of these warrant further investigation of CS
o   Hypersensitivity to bright lights, sound, smell
o   Hypersensitivity to chemicals, pesticides, medication
o   Hypersensitivity to hot or cold
o   Hypersensitivity to pressure, touch, mechanical loading - active / passive movement
o   Increased responsiveness to stress, emotions, and mechanical load
·         Possibly related
o   Fatigue, concentration difficulties
o   Sleep disturbances, un-refreshing sleep
o   Swollen feeling, tingling, numbness
·         Pre-existing pain - local or generalized, in any area of the body before the onset of the current pain increases the possibly of CS
·         Abnormal disease course - slow recovery, recurrent pain

3. Examination - diagnose, establish severity, monitor progress and response to treatment, determine treatment parameters
·         Pressure pain threshold at sites remote to symptoms - pressure algometer showing pressure pain threshold below 4 kg/cm2
·         Sensitivity to touch at sites remote to symptoms
·         Pain in response to cold pack at sites remote to symptoms
·         Pain in response to vibration at sites remote to symptoms
·         Heightened bilateral brachial plexus provocation - inconsistent pain with provocation
·         Heighten pain in comparison to pressure or tension at end feel  - ie small stretch with large pain
·         Increased pain response to exercise

4. Analyzing treatment response - CS may become apparent during treatment often with increased physical and emotional stress. Treatment including too aggressive MFR, exercise, mobs may contribute to the development of CS
·         New symptom development
·         Expansion and aggravation of symptoms
·         Altered treatment response
o   Non-responder
o   Post-exertional malaise
o   Decreased pain threshold in manual treatments

 

Mechanisms-based Classifications of Musculoskeletal pain (Hilton 2011, Smart 2011 'chronic LBP')
·         There is no direct measure or single assessment tool
·         Predictive rules are about 90% to 96% accurate - do your best and watch for evidence of an incorrect judgment
·         Can have combinations of various classifications - 50/50 or 40/60 etc

Nociceptive pain
·         Often found in acute pain and inflammation states
·         Strongest predictor - symptoms localized to area of injury or dysfunction even with some somatic referral. 
·         Second most important criterion - absence of dysesthesias
·         Pain usually intermittent and sharp with movement
·         Maybe constant, dull, throb with rest
·         Aggravating and easing factors follow common musculoskeletal pattern
·         Responds easily to mechanical treatment
·         Absence of burning, shooting, electrical shock pain, night pain
·         Pain generators include: inflammation / chemical irritation, ischemic / trigger points, mechanical pain

Peripheral neuropathic pain or peripheral sensitization (ie pudendal neuralgia)
·         Strongest predictor - pain referred in a dematomal or cutaneous pattern
·         Adverse neural tension signs – parasthesia, itching, dysesthesia
·         History of nerve injury, pathology or mechanical injury to nerve
·         Local irritation, swelling, muscle spasm
·         Motor weakness
·         History of trauma with poor healing
·         Lack of typical response to mechanical treatment
·         Pain generators include: Mechano-sensitive, ischemic-sensitive, chemo-sensitive, cross excitation

Central sensitization
·         Strongest predictor = disproportionate, non-mechanical pain, and unpredictable pattern of pain provocation
·         Pain disproportionate to type of injury or pathology
·         Pain longer than 12 weeks
·         Pain responds to stress and anxiety
·         Pain increased by small movement or no movement,
·         Diffuse and bilateral pain and tenderness
·         Burning shooting, crushing, non-dermatomal, allodynia or hyperalgesia (painDETECT questionnaire)
·         Multiple systems involved – sleep, bladder, bowel, muscles, joints, immune system
·         Depression, fear avoidance, catastrophization
·         Previous treatment failure
·         Pain generators: dorsal horn mediated,  forebrain mediated descending facilitation, loss of spinal cord inhibitory interneurons

Hilton S, Vandyken C. The puzzle of pelvic pain – a rehabilitation framework for balancing tissue dysfunction and central sensitization I: pain physiology and evaluation for the physical therapist.  J of Women’s health PT. 2011;35(3):103-113. 

Smart KM, et al. The discriminative validity of “nociceptive,” “peripheral neuropathic”, and “central sensitization” as mechanism-based classifications of musculoskeletal pain. Clin J Pain 2011;27(8):655-663

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.