Complex Regional Pain Syndrome(CRPS)

Ramani VijayanUniversity Malaya Medical Centre

Kuala LumpurMalaysia

CRPS

Is a debilitating painful condition in a limb Associated with sensory, motor, autonomic, skin and

bone abnormalities

PAIN is the leading symptom Often associated with limb dysfunction Psychological Distress

It commonly arises after injury to a limb (sometimes trivial)

CRPS

Type 2Type 1

Absence of a major nerve lesion

Presence of a major nerve lesion

(Reflex sympathetic dystrophy Sudeck’s Atrophy )

(Causalgia)

Historical Background First described by Weir Mitchell after the American

Civil War in 1872 When he encountered soldiers who were injured by gun-shot

wounds exhibiting “bizarre” symptoms and coined the term “Causalgia”

Early 20th century Peter Sudeck Described features of pain, swelling, atrophy etc. following

minor injury to limbs – hence this phenomenon came to be called “Sudeck’s atrophy”

A few years on – its association with the sympathetic nervous system was recognized and hence the term “reflex sympathetic dystrophy” was increasingly used

IASP Consensus group - in 1994

The presence of an initiating noxious event, or a cause for immobilization

Continuing pain and allodynia which is disproportionate to any inciting event

Evidence at some time of oedema, changes in skin blood flow, abnormal sudomotor activity in the region of pain

The diagnosis is excluded by the existence of other conditions that can account for the degree of pain and dysfunction

Criteria 2-4 must be satisfied

Continuing pain, allodynia, or hyperalgesia after nerve injury, not necessarily limited to the distribution of the injured nerve

Evidence at some time of oedema, changes in skin blood flow, abnormal sudomotor activity in the region of pain

The diagnosis is excluded by the existence of other conditions that can account for the degree of pain and dysfunction

All 3 Criteria must be satisfied

Complex Regional Pain SyndromeTYPE I TYPE II

1994 IASP Criteria

Proved to be extremely sensitive

Insufficiently specific Over diagnoses of the

syndrome Difficult to validate

In 2003, a workshop was held in Budapest

Published in 2007 Modified diagnostic

criteria Better discrimination

between CRPS and Non-CRPS neuropathic pain

IASP revised criteria – “Budapest criteria”

Continuing pain that is disproportionate to any inciting event

At least one symptom reported in at least 3 of the following categories Sensory: Hyperesthesia or allodynia Vasomotor: Temperature asymmetry, skin colour changes,

skin colour asymmetry Sudomotor/ Oedema, sweating changes or sweating

oedema asymmetry

Motor / Trophic Decreased range of motion, motor dysfunction (E.g. weakness, tremor, dystonia), or trophic changes (e.g. hair, skin, nails)

Criteria continued ……………

At least one sign at time of evaluation in at least two of the following categories Sensory: Evidence of hyperalgesia (to pinprick),

allodynia (to light touch), temperature

sensation, deep somatic pressure or joint movement Vasomotor: Evidence of temperature asymmetry (>1°C),

skin colour changes or symmetry

Sudomotor/ Evidence or oedema, sweating changes, or Oedema sweating asymmetry

Motor/Trophic Evidence of deceased range of movement, motor dysfunction

(E.g. weakness, tremor, dystonia), trophic changes (E.g. nail, skin, hair)

No other diagnosis explaining the signs and symptoms

More stringent criteria in a research setting: to increase specificity

At least one SYMPTOM in Three ‘SYMPTOM’ categories

At least one SIGN in Three ‘SIGN’ categories

For diagnosis of CRPS in a Research Setting

Epidemiology A population study from the Netherlands showed

Incidence of 26 in 100,000; Female : Male ratio of 3.5:1 Peak incidence in the age group of 55-70 years Upper limb more common than the lower Fracture was the most common precipitating factor CRPS I more common than CRPS II

(de Mos M et al. Pain 2007; 129:12-20)

This was 4 times that of a previous population study in the US – 5.5 / 100,000

Pathophysiology Not well understood for many years Renewed research interest

Revised diagnostic criteria Availability of animal models of CRPS

Pain 2015; 156: S94-S103

Inciting event – Trivial injury to the limb or injury to a peripheral nerve

Inflammation is exaggerated for yet unclear reasons inflammatory mediators leading to swelling, changes in

colour, increased skin temperature Pain and hyperalgesia Hyperhidrosis / hypohidrosis due to mediators such as

neuropeptides (Substance P, CGRP, bradykinin) Trophic changes due to cytokines Motor function is also impaired by peripheral inflammation

Increased levels of TNF-α, with a decrease in anti-inflammatory cytokines

Neuropeptides – released by sensitized peptidergic nociceptors ( neurogenic inflammation)

Endothelin-1 – potent vasoconstrictor (hyperalgesia) Autoantibodies on surface structures of β2-adregeric

receptors and m2-cholinergic receptors (which provides a link to the sympathetic nervous system)

In a significant subset of patients, CRPS gradually “centralizes” – (time frame varies with individuals) Mechanical hyperalgesia Non-dermatomal sensory deficits Body perception disturbances Movements disorders

Conceptual model of CRPS -

• Enhanced anti-dromic secretion of Neuropeptides

• Enhanced release of Immune mediators

• Surface binding auto-antibodies

• Contributes to changes in sensory nerve function and axonal degeneration

• Viscous cycle is set in motion

Electrical Stimulation induces Plasma Protein Extravasation in CRPS

Pathophysiology which includes central components

Clinical Features are a continuum Stage One (acute stage – 6-8 weeks after injury)

Warmth, coolness, burning pain, oedema, increased sensitivity to touch, increased pain with hyperalgesia, accelerated hair / nail growth, tenderness or stiffness of joints, spasm, bone changes on X-ray

Decreased sympathetic activity

Clinical Features of CRPS Stage Two: Dystrophic phase ( can last several

months) Pain is constant – throbbing, burning, aching, exaggerated by

stimuli Affected limb may still have oedema, cool, mottled appearance Nails – brittle and ridged Pain and stiffness of joints persist Muscles – tremors, signs of wasting

Psychological distress sets in (mainly from lack of pain relief)

Changes in body perception (limbs) Increased sympathetic activity

Stage 3 – Atrophic phase (unlimited amount of time)

Typically the patient has had CRPS for 3+ years Pain is still constant (varies in degree depending on

the patient) Skin is cool, thin and shiny Atrophy of limb – with contractures of joints Muscle wasting Increase in osteoporosis Unlikely for sympathetic blocks to be effective

Central changes CRPS features can extend beyond the original region

Diagnosis Clinical – There are no specific tests Differential diagnosis needs to be considered and

excluded

• 53 year old male patient• Clinical features of pain and allodynia• Limited to the fourth and fifth fingers• Bluish and significantly cooler

• Thermography showed only the innervation of the ulnar nerve was colder

• Traumatic ulnar paresis

• Diagnosis : Posttraumatic neuralgia

Having a Check-List will help with the Diagnosis

Item 4. No other diagnosis explaining the signs and symptoms

Management

Early Recognition is the key to Management

• Patients may be first seen by a host of different specialists

• It is important to create awareness about CRPS in these groups

• Early recognition and referral for appropriate therapy can improve chances for better management

Budapest diagnostic criteria (A–D must apply).

Andreas Goebel Rheumatology 2011;rheumatology.ker202

© The Author 2011. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

CHECK LIST

The 4 Pillars of Management

Pain Relief

Corticosteroids Calcium-regulating drugs

Calcitonin, Alendronate Opioids Anti Neuropathic drugs Ketamine Sodium channel blockers

Lignocaine ClonidineVery little consistent information is available for these pharmacological agents

In early CRPS – may be useful Has been tried

When others fail to provide pain relief TCA, gabapentin, pregabalin Ketamine ( Low dose infusions have

been tried with mixed results)

Pain relief – so that patients are able to comply with physical therapy, which is the KEY to management

Medications

Procedures Intravenous Regional

Techniques Local anaesthetics Guanethidine

Selective Sympathetic ganglion blocks Useful is some cases of

sympathetically maintained pain

Spinal Cord Stimulation and Neuromodulation

Physical and Vocational therapy

Patient education Stretching General exercise and

Strengthening Desensitization Gait re-education TENS Postural control Oedema control

strategies Sleep hygiene

Graded Motor Imagery Mirror Visual Feedback

Patient viewing non‐reflective surface with painful limb hidden.

C. S. McCabe et al. Rheumatology 2003;42:97-101

© British Society for Rheumatology

Patient viewing non‐painful limb in mirror with painful limb hidden.

C. S. McCabe et al. Rheumatology 2003;42:97-101

© British Society for Rheumatology

Psychological Therapy

Patient education and support Goal setting Relaxation techniques Pacing techniques Coping skills Facilitating self-management of condition

Watch for Yellow Flags

In Conclusion CRPS is a chronic debilitating painful condition There has been significant advances in our

understanding of its Pathophysiology Early diagnosis and management – is essential to

help patients and reduce suffering The Budapest Criteria should help while excluding others

A Multidisciplinary Approach to Management has been shown to be beneficial With particular emphasis on Patient Education and Support

https://www.rcplondon.ac.uk/sites/default/files/documents/complex-regional-pain-full-guideline.pdf