Somotosensory Assessment and Rehabilitation of Allodynia: the SARA pilot study

Tara Packham, OTReg(Ont), PhD candidateJoy MacDermid, PT, PhDSchool of Rehabilitation Sciences, McMaster UniversityHamilton, Ontario, Canada

Collaborators

Co-Investigators: Dr. Norm Buckley Dr. James Bain

Committee Members Dr. Norm Buckley Dr. Susan Michlovitz

Funding and oversight

This study has funded by the New Investigators Fund at Hamilton Health Sciences.

This study has been approved by the Hamilton Integrated Research Ethics Board, and is posted on www.clinicaltrials.gov

Introduction

Complex Regional Pain Syndrome (CRPS) is a form of neuropathic pain that develops after trauma; it is seen more often in the upper extremity (3:2) and more often in women (2:1) [deMos et al, 2007]

Background

CRPS is characterized by variable signs and symptoms Sensory (hyperalgesia, allodynia)

Motor/trophic ( stiffness, dystonia, skin & nail changes)

Vasomotor (temperature and colour)

Sudomotor (edema, hyperhidrosis)

No diagnostic test: identification based on clinical criteria with high sensitivity and lower specificity (Harden et al, 2007)

This variability also creates challenges for the clinical measurement necessary for describing current status, prognosis and treatment outcomes (Packham et al, 2012)

Measurement challenges in CRPS

Symptom variability Variable presentation Lack of a common lexicon Lack of a pathognomonic diagnostic test

Ongoing refinement and validation of criteria for clinical diagnosis

Inconsistent use of outcome measures

Perspective

Was I measuring what was important to client?

Was what I measured capturing key changes?

How can my measures better inform my treatment choices?

Do my measures let me compare my patients to how other professionals were measuring them or to the literature?

Development of the Hamilton Inventory for CRPS

Goals of the assessment: a common framework to evaluate patients, make treatment decisions, and monitor progress

foster research by allowing comparisons between patients with CRPSI or CRPSII, involving any extremity

a broad framework which included impairment, activity and participation perspectives but was condition-specific

a reliable and valid tool for research and clinical practice

identify patterns of symptoms, and discriminate between patient groups based on functional symptom clusters.

Development of the Hamilton Inventory for CRPS

Phase 1

• Literature review to identify all constructs and potential items

• Systematic review of other tools

Phase 2

• Initial draft and separation into patient-reported and clinician-based components

• Expert review and pilot testing

Phase 3

• Cognitive debriefing studies of the clinician based (n=19) and patient-reported (n=45) components

• Revisions and development of standardization

Current versions and subscales

Clinician Based• Sensory• Autonomic• Motor• Trophic• 14 items scored

none/mild/moderate/severePatient-Reported• Physical symptoms• Daily functioning• Coping and social supports• 40 items scored 0-6 using a

mixture of agreement [Likert] and frequency scales

Sample question:CB-HI-CRPS

Testing: Touch test tube of cold water to skin for 3 seconds. Repeat over 3 different zones within affected area. Rate response as above.Instructions: I am going to touch you with this test tube of cold water; tell me how it feels to you. (Allow patient to respond then ask) Does it hurt?

Cold Hyperalgesia [sensory subscale]:Definition: an exaggerated painful sensation evoked by low-temperature stimulation Scoring: 0 = None, no complaints of pain; may report that tube feels cold. 1 = Mild, patient reports discomfort with cold but no physical behaviours evident 2 = Moderate, patient reports pain, may show a behavioural response such as flinching, grimacing, or vocalizing discomfort 3 = Severe, patient reports pain and has a clear behavioural response; may decline to be tested

Question list:CB-HI-CRPS

Allodynia Cold hyperalgesia Guarding Skin temperature asymmetry Vascular function: mottling Sweating (hyperhidrosis or anhydrosis)

Edema Hair growth Nail quality Skin quality Movement expected given initial injury

Movement expected given time elapsed since injury

Muscle tone Incoordination

Sample questions:PR-HI-CRPS

I need to concentrate in order to make my affected limbs move.

Pain prevents me from participating in activities throughout my day.

I still enjoy the things I used to enjoy

Always

65

Often

4 3

Some times

2 1

Never

0

Always

65

Often

4 3

Some times

2 1

Never

0

Strongly agree

0Agree

1Slightly agree

2Neutral

3Slightly disagre

e4

Disagree

5

Strongly

disagree6

Ongoing development of the Hamilton Inventory for CRPS

Phase 4

• Use in a clinical trial of somatosensory rehabilitation

• Data will provide estimates of inter-rater and test-retest reliability, divergent validity, and responsiveness

Phase 5

• Internet-based distribution through patient advocacy networks for large-scale testing of patient-reported component (internal consistency, factorial validity of subscales, Rasch analysis, test-retest reliability)

Phase 6

• Translation and cultural validation in French?

Skin temperature asymmetry(STA)

Skin temperature side differences have been used to assist in the diagnosis of CRPS (Oerlemans et al, 1999; Wasner et al, 2002)

Issues: Lab-based assessment not practical for

clinical use Symptom variability of temperature

differences No evidence for cut-points (1.5 degrees

C) Asymmetry may not be a valid sign for

both CRPS I and II since also seen in peripheral nerve injuries

Skin temperature asymmetry

Hypothesis: Combining a cold pressor test (CPT) with skin temp measurements could create a thermoregulatory stress to consistently reproduce temperature asymmetry

Pilot work demonstrated: Safety of a cold pressor test [changes in

blood pressure, pain] Reliability of inexpensive IR thermometers

[no effect of room temperature or humidity] Reliability of measurement points [fingertip

as reliable as palm or dorsum of hand](Packham et al, 2012)

Results of previous pilot work on STA

CPT as a thermoregulatory stressor30 seconds of cold immersion [foot] created mean

skin temperature change [hand] 1.08°C (SD 0.75) in all participants

Skin temperature asymmetry post CPTNo statistically significant change (p=0.26) in

asymmetry between groups (n=7, 13)

CRPS rehabilitation

Historical “expert” rehabilitation recommendations

Stress loading Desensitization Functional restoration

through increasing activity (OT)

Psychotherapy Physiotherapy in

conjunction with medical interventions

Watson & Carlson, 1987; Stanton-Hicks et al, 1995

Contemporary “evidence-based” rehabilitation recommendations

Graded motor imagery Mirror therapy Cognitive behavioural

therapy Medical management

to support participation in rehab

Ezendam et al, 2009; Bowring et al, 2013; Turner-Stokes & Goebel, 2012; Perez et al, 2012

Allodynia

Allodynia is a key sensory feature of CRPS, but is also seen in peripheral nerve injuries (PNI)

The International Association for the Study of Pain defines allodynia as “… a painful response to a non-noxious stimuli.” (Merskey and Bogduk, 1994)

Mechanical (light touch, vibration, pressure)

Thermal (hot or cold at a sub-noxious threshold)

SomatosensoryDefinition: (adj.) of or relating to the perceptions of sensations from the skin and bodily organs; bodily sensations not associated with the primary sense organs (vision, hearing, taste, smell) (Stedman’s Medical Dictionary, 2002)Key concepts

Background

Somatosensory rehabilitation (Spicher, 2006) Method for assessment and treatment of allodynia

Identifies specific nerve branch as the signal generator

Uses somatosensory inputs (vibrotactile counterstimulation) into the same cord of the brachial plexus (not the area of sensitivity) to change the pain perception and address central sensitization

Sensory re-education, not desensitization

Several published case series but all with risk of bias (Spicher et al, 2008; Spicher et al, 2009)

Background:Somatosensory rehabilitation

Certification process for therapists or doctors to use somatosensory rehabilitation method (through University of Brussels)

40 hours of training + submission of a case study demonstrating correct use of principles

Supported by CoP blogs (closed) and multi-lingual e-News letter (open access)

International uptake (as of April 2014):873 therapists and physicians certified from 28 countriesIn Canada:142 French-speaking9 English speaking

Study Purpose

PRIMARY RESEARCH QUESTION: Is somatosensory rehabilitation effective for the treatment of allodynia after complex regional pain syndrome or peripheral nerve injury?

3 study components

1. Pilot study of the effectiveness of a somatosensory rehabilitation protocol for the treatment of allodynia resulting from PNI and/or CRPS

2. Development and examination of the measurement properties of multiple assessments for the evaluation of CRPS and PNI and the associated signs and symptoms, including: a. the Hamilton Inventory for Complex

Regional Pain Syndrome (HI-CRPS) b. the Radboud Evaluation of

Sensitivity – English version (RES-E)c. allodynography

3. Evaluation of the diagnostic accuracy and discriminative validity of skin temperature asymmetry in the limbs for the identification of CRPS

Participants

N=30 in each of 4 groups: Persons with CRPS (type I or II) Persons with peripheral nerve injury (PNI)

Persons with a recent hand fracture (<12 weeks)

Healthy volunteers (Skin temperature measures only)

Total N=120

StudyMethods

Pre-Trial: Translation of the Radboud Evaluation of Sensitivity (RES-E) from

Dutch to EnglishBaseline: RES-E, 10 test, ICE test, STA, VAS pain, McGill, HI-CRPS, PRWHE, PCS,

ROM, dynamometry

Treatment: a) Somatosensory rehabilitation, or b) usual

treatment3 Month follow-up: RES-E, 10 test, ICE

test, STA, VAS pain, McGill, HI-CRPS, PRWHE, PCS, ROM, dynamometry, global

rating of change6 Month follow-up: RES-E, McGill, PR-HI-

CRPS, PCS, global rating of change

Methods:Allodyno-graphy

Mapping technique allows quantification of painful area, and precise identification of the nerve branch involved Map is always outlinedwith a 15 g monofilament; point is marked where pressure becomes 3/10 pain on VAS scale• Triangle marks the measurement reference point• Arrows indicate the axis of

theperimeter points

Methods:Rainbow Pain Scale

Categorical measurement of the intensity of allodynia (more intense = smaller filament/less pressure needed to elicit a pain response: 3/10 on VAS)

15g 8.7g 3.6g 1.5g 0.7g 0.2g 0.04g

Single stimulus applied to centre of allodynic territory with “red” filament (0.04 gram / SWMF 2.44); then move to larger filaments until person identifies the first size of filament that produces pain (3/10 VAS)

Methods: Assessment of STA with a cold pressor test

1. Measurement of skin surface temperature in both hands using digital infra-red thermometer over autonomous territories of median, ulnar and radial nerves

2. Immersion of foot in a cold water bath [5 degrees C] for 30 seconds

3. Immediate re-measurement of skin temperature in the hands

HI-CRPS

Hamilton Inventory for Complex Regional Pain SyndromeClinician based: 14 items 4 point scale (none, mild, moderate,

severe) Detailed scoring instructions for

standardizationPatient-reported: 40 items 7 point scales (agreement or frequency) Content validity explored with cognitive

debriefing (n=45 participants), leading to modifications and additions (previously had 35 items)

Radboud Evaluation of Sensitivity

Developed to measure sensitivity (allodynia and dysthesia) in persons with CRPS of the upper limb (Cup et al, 2002)

Psychometric data for Dutch version never published but used clinically in Netherlands

Quick and easy to administer with minimal equipment required; 8 items

Ratio scaling: ratings are comparisons to unaffected limb (rated no difference [O%]to totally different [100%]) using a VAS

Do you feel a difference between your right and left hand if you touch:a) Your hairf) A towel

Radboud Evaluation of Sensitivity

Translation and cultural validation (Beaton et al, 2000)Forward translation from Dutch to English

by 3 native Dutch speakers (OT, PT, layperson, + Google)

Backwards translation from English to Dutch by 3 native English speakers (OT, 2 laypersons)

Review by oversight committee (expert panel, including developer of original assessment)

Psychometric testing• Reliability (test-retest), internal

consistency• Validity (convergent: 10 test, Rainbow

Pain Scale; discriminative: allodynia vs. no allodynia)

• Responsiveness

Anticipated Results

Skin temperature asymmetry Fully powered for sensitivity and specificity analyses

Estimates of discriminative validity by comparing to persons with the normal sequelae of trauma and PNI

Anticipated Results

Hamilton Inventory for CRPS Reliability: inter-rater, test-retest, internal consistency

Validity: discriminative (comparing persons post# and PNI); construct (compared to PRWHE, Pain Catastrophizing); convergent (PR-HI to CB-HI); factorial (subscale analysis)

Responsiveness?

Anticipated Results

Allodynography Reliability: test-retest, inter-rater Construct validity (RES, 10-test), convergent validity (ICE test) and responsiveness

Somatosensory rehabilitation Estimates on effectiveness for powering a future RCT

Future directions

Validation of allodynography against pressure perception and pressure pain threshold

Repeating STA results in persons with lower extremity CRPS

Examining STA in babies with OBPI (no cold stress)

Trial of somatosensory rehabilitation for allodynia of the chest wall after chemotherapy and/or radiation and/or surgery for women with breast cancer

References

Beaton et al. Guidelines for the Process of Cross-Cultural Validation. SPINE 2000; 25(24): 3186–3191.

Cup EHC, van de Ven-Stevens LAW, Corstens-Mignot MAAMG. Occupational Therapy for patients with Complex Regional Pain Syndrome type I of the upper extremity. 2002; Congress proceedings: Dutch Journal of Hand Therapy.

de Mos M, de Bruijn AG, Huygen FJ, et al. The incidence of complex regional pain syndrome: a population-based study. Pain. 2007;129:12–20

Harden RN, Bruehl S, Stanton-Hicks M, Wilson PR. Proposed new diagnostic criteria for complex regional pain syndrome. Pain Med 2007;8(4):326– 31.

Oerlemans, H.M., Perez, R.S., Oostendorp, R.A., Goris, R.J. (1999). Objective and subjective assessments of temperature differences between the hands in reflex sympathetic dystrophy. Clinical Rehabilitation, 13: 430–438

Packham T, Fok D, Frederiksen K, Thabane L, Buckley N. (2012a) Measuring skin temperature asymmetry to detect complex regional pain syndrome: A methodological pilot study. 2012 Oct-Dec;25(4):358-61; quiz 362. doi: 10.1016/j.jht.2012.06.003.

References

Packham T, MacDermid J, Henry J, Bain J. (2012b) A systematic review of the psychometric evaluations of outcome assessments for complex regional pain syndrome. Disabil Rehabil 2012, 34(13), 1059-69. PMID: 22149250

Packham T, MacDermid J, Henry J, Bain J. The Hamilton Inventory for Complex Regional Pain Syndrome: A Cognitive Debriefing Study of the Clinician-based Component. J Hand Ther 2012; 25:97–112.

Spicher CJ. Handbook for Somatosensory Rehabilitation (English ed.) Sauramps Medical: Paris. 2006.

Spicher CJ, Mathis F, Degrange B, Freund P and Eric Rouiller (2008). Static mechanical allodynia (SMA) is a paradoxical painful hypo-aesthesia: observations derived from neuropathic pain patients treated with somatosensory rehabilitation. Somatosens Mot Res 25(1):77-92.

Spicher CJ, Freund P, Desfoux N, and Della Casa R. (2009). Time course of disappearance of static mechanical allodynia through somatosensory rehabilitation: reexamination of a larger cohort of neuropathic pain patients. E-News for Somatosensory Rehabilitation; 6(4): 151-170.

Uddin Z, MacDermid J, Packham T. The ten test for sensation. J Physiother. 2013 Jun;59(2):132. doi: 10.1016/S1836-9553(13)70171-1. PMID: 23663804

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