Central sensitization

Central sensitization

A.THANGAMANI RAMALINGAM

OBJECTIVES

Basics of Central sensitization(CS)Neuro immunology Recognition of CSImplications for physiotherapy/therapist(assessment/management/guidelines) What Evidences say?

PAIN

An unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage ISAP (1979)

Pain is a noxious unwanted perceptionPain is subjective, individual and modified by degrees of attention, emotional state and the conditioning of past experiences. (Livingstone 1943)

PHYSIOLOGY OF PAIN

Influenced by Limbic system & Reticular formation

Nociceptive processing

Pain sensitization

Primary hyperalgesia or peripheral pain sensitization pain

Secondary hyperalgesia or central sensitization

Unimodal/polymodal nociceptors

Central sensitization

Top down mechanisms

Bottom up mechanisms

Augmentation of responsiveness(Meyer et al 1995)Altered sensory processing (Staud et al.,2007)Malfunctioning of descending inhibitory system(Meeus et al., 2008)Potentiation of neuronal synapses (zuho 2007)Temporal summation of secondpain or windup(Nijis 2007)

Pro inflammatory cytokines(samad et al)

Issue tactile allodynia/punctuate hyperalgesia/temporal summation/sensory after effects

Increased sensitivity to various stimuli Light TouchColdHeatPressure or punctuateChemical substancesElectrical stimuli

Reductionist

Rationalist

Neuro immunology

Neuro immunological response

Glial cells-neuro immunology

Dr. Watkins, at the Headache Cooperative of the Pacifics 2009 Winter Colloquium

Glial cell activation has been demonstrated in every clinically relevant animal model study to date, including that of peripheral nerve injury, bone cancer, multiple sclerosis (MS), spinal cord injury, herniated disks, low back pain, and migraine, noted Dr. Watkins, Professor of Psychology and Neuroscience at the University of Colorado at Boulder. Targeting the glial cells and their proinflammatory products doesnt make a patient analgesic, and it doesnt suppress all pain sensitivity. It simply returns the pain to normal. It removes the abnormal pain,

NMDA Vs

MSD-neuro immunology

Biomechanical injury/loading

Altered electro physiology

Change in neuro immune response

Conditions

Rheumatoid arthritisOATemporo mandibular disordersFibromyalgiaChronic neck and back pain-disc pathologiesHeadacheNeuropathic painCRPSVisceral pain hypersensitivity syndrome

Central sensitization syndromes

Co morbidity of conditionsIBS/FM/CFS/CWP/headache /MSDs

Recognition of Central sensitization

Screening

Using medical diagnosis

History taking

Clinical examination

Analyzing the treatment responses

Clinical decision making

Diagnostic criteriaeg:2010 PRELIMINARY DIAGNOSTIC CRITERIA (EXCERPT)CRITERIA Diagnostic criteria for fibromyalgia if the following 3 conditions are met:1.Widespread pain index (WPI) 7 and symptom severity (SS) scale score 5 or WPI 3 - 6 and SS scale score 9.2.Symptoms have been present at a similar level for at least 3 months.3.The patient does not have a disorder that would otherwise explain the pain.

BiomarkersClinical testing of hyper algesia/allodynia

Physiotherapy

Behavioral pain measures

Physiological measuresEMG muscle tensionHeart rateSkin temperatureEEG and brain imagingSelf-report measuresVisual Analog Scale(VAS)Graphic Rating Scale(GRS)Simple Descriptor Scale(SDS)Numerical Rating Scale(NRS)Faces Rating Scale(FRS)McGill Pain Questionnaire

Pain Rating Scales

Pain Discomfort Scale MPQ

Sixteen Pain Behaviors-biopsychosocial assessment Rudy et al.

Asymmetry Slow response time Guarded movement Limping Bracing Personal contact Position shifts Partial movement

Absence of movement Eye movement Grimacing Quality of speech Pain statements Limitation statements Sounds Pain relief devices (under use)

Quantitative sensory testing (QST)

compare pressure pain threshold (PPT) values of myotomes, sclerotomes, and dermatomes corresponding to segments-algometertwo-point discrimination (TPD)-aesthesiometervibratory sensation

thermal pain threshold and tolerancesuprathreshold heat pain response.DNIC-diffuse noxious inhibitory control assessment

Measurement of secondary hyperalgesia

CSI

(test-retest reliability = 0.817; Cronbach's alpha = 0.879)

SCREENING TOOLS FOR NEUROPATHIC PAIN.

Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) Neuropathic Pain Questionnaire (NPQ) Douleur Neuropathique en 4 questions (DN4) pain DETECT ID-Pain

Mechanisms-based classifications ofmusculoskeletalpain

'Disproportionate, non-mechanical, unpredictable pattern of pain provocation in response to multiple/non-specific aggravating/easing factors', 'Pain disproportionate to the nature and extent of injury or pathology 'Strong association with maladaptive psychosocial factors (e.g. negative emotions, poor self-efficacy, maladaptive beliefs and pain behaviours) 'Diffuse/non-anatomic areas of pain/tenderness on palpation'. This cluster was found to have high levels of classification accuracy (sensitivity 91.8%, 95% confidence interval (CI): 84.5-96.4; specificity 97.7%, 95% CI: 95.6-99.0).

Mechanisms-based classifications ofmusculoskeletalpain: part 1 of 3: symptoms and signs ofcentralsensitisation in patients with low back ( leg) pain.Smart KM1,Blake CStaines A,Thacker MDoody C Man Ther.2012 Aug;17(4):336-44. doi: 10.1016/j.math.2012.03.013. Epub 2012 Apr 23

Management

Guidelines

1. Assessment of pressure pain thresholds at sites remote from the symptomatic site;2. Assessment of sensitivity to touch during manual palpation at sites remote from the symptomatic site; and3. Assessment of pressure pain thresholds during and following exercise

Nijs J, Van Houdenhove B, Oostendorp R a B. Recognition of central sensitization in patients with musculoskeletal pain: Application of pain neurophysiology in manual therapy practice. Manual therapy [Internet]. Elsevier Ltd; 2010 Apr [cited 2014 Feb 24];15(2):13541. Available from: http://www.ncbi.nlm.nih.gov/pubmed/20036180

Education

Face to face sessionBooklet/written homeworkApplication

Anterior cingulate cortex responds to physical and emotional pain -EXERCISE

Biofeedback

Gauthier et al. (1994) for headaches

Behavioral/Cognitive Approaches

Guided Imagery Systematic desensitizationReframingMeditationStress management techniques not as effective as other techniquesThinking about the pain and expectations Bandura et al. (1987) an increase in endorphines with cognitive technique

How do placebos influence pain?

Patients expectation about the effects of the treatmentAirily (2008) study of differential effectives of placebo based on perceived cost ($.10 v. $2.50)http://www.npr.org/templates/story/story.php?storyId=87938032Classical conditioningPatients may change behaviorsPhysiological changes which inhibit the experience of pain

10khz medium frequency current has marked discrimination between motor and pain thresholdClinically we use 2and 4khz equipments for therapy

Evidences

Neck/back pain

Weak pain daysCS pain intensity

Strong pain daysCS no of pain areas

Post operative cases

DAY(mean/sd)

20HZSEN

2OHZMOT

2OHZPAIN

50 HZSEN

50HZMOT

50HZPAIN

100HZSEN

100HZMOT

100HZPAIN

NPRS

GROC

ONE

4.800

6.733

9.533

4.97

6.933

9.733

5.133

7.066

10.233

4.73

5.0

THREE

5.300

7.033

9.600

5.40

7.100

9.933

5.433

7.2000

10.233

3.43

5.63

SEVEN

5.333

7.166

9.700

5.43

7.300

10.03

5.566

7.433

10.366

2.40

5.96

Chronic back pain cases

DAY(mean/sd)

20HZSEN

2OHZMOT

2OHZPAIN

50 HZSEN

50HZMOT

50HZPAIN

100HZSEN

100HZMOT

100HZPAIN

NPRS

one

4.4

6.25

10.8

4.75

6.6

11.2

4.75

6.6

11.5

5.05

three

4.55

6.5

11.5

4.8

6.6

11.3

5.2

7.3

12.1

4.0

five

5.05

6.8

11.8

5.10

7

12

5.3

7.2

12.4

3.6

Response to 100 hz low frequency current on different groups

49

OA

Interventions such as cognitive-behavioraltherapyand neuroscience education potentially target cognitive-emotionalsensitization(and descending facilitation), and centrally acting drugs and exercisetherapycan improve endogenous analgesia (descending inhibition) in patients with osteoarthritis.

Phys Ther.2013 Jun;93(6):842-51. doi: 10.2522/ptj.20120253. Epub 2013 Feb 7.Pain treatment for patients with osteoarthritis andcentral sensitization.Lluch Girbs E1,NijsJ,Torres-Cueco R,Lpez Cubas C

Activity dependent treatmentsin neuropathic pain

Treadmill running

Electrical stimulation

,TR induced strong agonistic effects in relieving pain. TR reduced the levels of pro-nociceptive factors such as BDNF, NGF and GDNF in DRG. Combination of ES and TR induced intermediate levels suggesting an optimal balancing of treatment effects.

ES enhanced motor and sensory reinnervationES speeded up expression of BDNF and GDNF in DRG ., and of BDNF and NT3 in the ventral horn.

Exp Neurol.2013 Feb;240:157-67. doi: 10.1016/j.expneurol.2012.11.023. Epub 2012 Nov 30.Differential effects of activity dependent treatments on axonal regeneration and neuropathic pain after peripheral nerve injury.Cobianchi S1,Casals-DiazL,Jaramillo J,Navarro X

TENS

Positive study

Negative study

Frequency-dependent antihyperalgesic and analgesic effects in humans.No long-lasting analgesic and antihyperalgesic effects of a single TES treatment(TES(60Hz) > TES(100Hz))

Anesth Analg.2010 Nov;111(5):1301-7. doi: 10.1213/ANE.0b013e3181e3697e. Epub 2010 Jun 8.The analgesic and antihyperalgesic effects of transcranial electrostimulation with combined direct and alternating current in healthy volunteers.Nekhendzy V,Lemmens HJ,Tingle M,Nekhendzy M,Angst MS.

Tens influence on centrally sensitized OAk patients may be augmented to the input of electrical stimuli. Adverse therapyeffect of tens. To increase treatment effectiveness - identify a subgroup of symptomatic OAk patients, i.e., non-sensitized patients.

Trials.2012 Feb 21;13:21. doi: 10.1186/1745-6215-13-21.Effect of tens on pain in relation tocentral sensitizationin patients with osteoarthritis of the knee: study protocol of a randomized controlled trial.Beckwe D1,De Hertogh W,Lievens P,BautmansI,Vaes P.

Acetaminophen, serotonin-reuptake inhibitor drugs, selective and balanced serototin and norepinephrine-reuptake inhibitor drugs, the serotonin precursor tryptophan, opioids,N-methyl-d-aspartate (NMDA)-receptor antagonists, calcium-channel alpha(2)delta (a2) ligands, ketamine ,pragabalin, duloxetine,transcranial magnetic stimulation. + transcutaneous electric nerve stimulation (TENS), manual therapy and stress management each target central pain processing mechanisms in animals that theoretically desensitize the CNS in humans

Message/tips for therapist

APPROACH to CS

To provide a comprehensive treatment for unexplained chronic pain disorders characterized by central sensitization, it is advocated to combine the best evidence available with treatment modalities known to target central sensitization

References

Woolf CJ. Central sensitization: Implications for the diagnosis and treatment of pain. Pain [Internet]. International Association for the Study of Pain; 2011;152(3):S215. Available from: http://dx.doi.org/10.1016/j.pain.2010.09.030Winkelstein B a. Mechanisms of central sensitization, neuroimmunology & injury biomechanics in persistent pain: implications for musculoskeletal disorders. Journal of electromyography and kinesiology: official journal of the International Society of Electrophysiological Kinesiology [Internet]. 2004 Feb [cited 2014 Feb 24];14(1):8793. Available from: http://www.ncbi.nlm.nih.gov/pubmed/14759754Nijs J, Van Houdenhove B, Oostendorp R a B. Recognition of central sensitization in patients with musculoskeletal pain: Application of pain neurophysiology in manual therapy practice. Manual therapy [Internet]. Elsevier Ltd; 2010 Apr [cited 2014 Feb 24];15(2):13541. Available from: http://www.ncbi.nlm.nih.gov/pubmed/20036180Nijs J, Wilgen CPV, Oosterwijck JV, Ittersum MV, Meeus M. How to explain central sensitization to patients with unexplained chronic musculoskeletal pain: Practice guidelines. Manual Therapy [Internet]. Elsevier Ltd; 2011;16(5):4138. Available from: http://dx.doi.org/10.1016/j.math.2011.04.005Smart KM, Blake C, Staines A, Doody C. Self-reported pain severity , quality of life , disability , anxiety and depression in patients classified with nociceptive , peripheral neuropathic and central sensitisation pain . The discriminant validity of mechanisms-based classifications of low back ( leg ) pain. Manual Therapy [Internet]. Elsevier Ltd; 2012;17(2):11925. Available from: http://dx.doi.org/10.1016/j.math.2011.10.002Smart KM, Blake C, Staines A, Thacker M, Doody C. Mechanisms-based classifications of musculoskeletal pain: Part 3 of 3: Symptoms and signs of nociceptive pain in patients with low back ( leg ) pain. Manual Therapy [Internet]. Elsevier Ltd; 2012;17(4):3527. Available from: http://dx.doi.org/10.1016/j.math.2012.03.002Smart KM, Blake C, Staines A, Thacker M, Doody C. Mechanisms-based classifications of musculoskeletal pain: Part 2 of 3: Symptoms and signs of peripheral neuropathic pain in patients with low back ( leg ) pain. Manual Therapy [Internet]. Elsevier Ltd; 2012;17(4):34551. Available from: http://dx.doi.org/10.1016/j.math.2012.03.00318. Smart KM, Blake C, Staines A, Thacker M, Doody C. Mechanisms-based classifications of musculoskeletal pain: Part 1 of 3: Symptoms and signs of central sensitisation in patients with low back ( leg ) pain. Manual Therapy [Internet]. Elsevier Ltd; 2012;17(4):33644. Available from: http://dx.doi.org/10.1016/j.math.2012.03.013

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