Lecture 6

RECOGNIZING CRPS I

(RSD)

Nelson Hendler, MD, MS

Former Assistant Professor of Neurosurgery

Johns Hopkins University School of Medicine

Past president –American Academy of Pain Management

Past president- RSD Association of America

www.DiagnoseMyPain.com

Definitions

• Allodynia- a painful response to a normally

non-painful stimulus.

• CRPS I –complex regional pain syndrome

type I, which used to be called reflex

sympathetic dystrophy.

• CRPS II – complex regional pain syndrome

type II, which used to be called causalgia.

IASP Definition of CRPS I(International Association for the Study of Pain)

• Pain in excess of what is expected. (This is a

very subjective definition, and not scientific)

• Swelling or edema

• Coldness or heat in limb

• Loss of hair

• Nail growth

• Can spread to other side

Diagnostic Criteria for CRPS I

The Sine Qua Non of Dx.

• Thermal allodynia (Raja, Campbell, Meyers-American Pain Society abstract,’96)

• Circumferential pain (Raja and Hendler, Current Practices in Anesthesiology, ‘90 )

• Not a cold limb –also found in radiculopathy, nerve entrapment, CRPS II.

• Not mechanical allodynia – also seen in nerve entrapment and radiculopathy as well.

• Not skin changes- also seen in CRPS II, N. entrap.

• Not edema – also seen in lymphatic damage,sprains

Flaws with Research Design

• Symptoms change over time, following three stages (Schwartzman, and Payne)

• These stages are based on severity or clusters of symptoms, not temporal staging.

• Many errors in literature, due to failure to report the stage, or list the clinical diagnostic criteria for the patient selection, resulting in difficulty doing meta analysis research, with highly variable outcome results, i.e. 12%-97% success rate for sympathectomy (Payne).

Definitions

• Circumferential: a location which

described a circumference, i.e. all the way

around something, like a tree or a limb.

• Tinel: a response to a tap on a nerve that

sends a sensation in the anatomical

distribution of that nerve, like hitting your

“funny bone” (the ulnar nerve).

Anatomy of Spinal Cord

• Sympathetics

Sympathetic

Chain

Dorsal Horn

of Spinal

Cord

Wide Dynamic

Range Neurons

Concepts

• The sympathetic nerves have origin in the thoracic spinal cord.

• They form ganglion outside the spinal cord.

• Their activity is controlled by the wide dynamic range neurons of the posterior horn.

• Sympathetics control functions such as blood vessel diameter, sweating, heart rate.

• The wide dynamic range neurons have neuronal plasticity, i.e. they can change activity over time.

MEDICAL FACTS ABOUT CRPS I (RSD)

• In early stages, CRPS I (RSD) is a disorder of sympathetic nerves.

• In later stages, CRPS I (RSD) is a disorder of the spinal cord, of the wide dynamic range neurons, in lamina II and V of the dorsal horn, and NMDA

• CRPS I (RSD) may spread to the countralateral limb, or ipsilateral limb, due to neuronal plasticity

• 71% of patients diagnosed with CRPS I (RSD) actually have just nerve entrapments, 27% have both (Hendler, Pan Arab Journal of Neurosurgery,’02)

• 80% of patiet diagnosed with CRPS I have nerve entrapments which respond to surgery (Dellon,et al, J. Brachial Plex Peripher Nerve Inj, 2009)

Theories about the Etiology of

CRPS I

• Auto-immune - Knobler

• Central - angry back firing C fibers - Ochoa

• Wide Dynamic Range neurons - Roberts

• Neuronal plastisity- Dubner

• Hyperpathia- Bennett

• Ephaptic connections - Sweet

• In reality, no-one really knows the cause.

PATIENT HISTORY

• There is no way to predict who will get CRPS I (RSD)

• Very often, a minor trauma will trigger CRPS I (RSD)

• Post-operatively, if there is a painful limb, the more likely diagnoses are nerve injury or compression, due to surgery or to the use of a tourniquet, infection, or an occult fracture

• Immediate post-op pain is not CRPS I (RSD)

• A tight cast may trigger CRPS I (RSD)

SYMPTOMS of CRPS I (RSD)

• Thermal allodynia is almost always present

• Pain is constant, but varies in intensity

• Pain is circumferential. The pain is not in a

peripheral nerve distribution

• Change of position of the limb does not

worsen the pain

• Other “classic” signs are highly variable

SIGNS of CRPS I (RSD)

• Pain is circumferential, around entire foot or arm.

• Pressure on the ulnar, radial, median, tibial, sural, superficial and deep peroneal nerves will be no more or less painful than pressure any where else on the limb.

• “Classic” edema may or may not be present

• “Classic” mottled skin and shiny skin may or may not be present.

• “Classic” hair/nail growth may or may not be present.

“CLASSIC” DIFFUSE

SWELLING OF CRPS I (RSD)

“CLASSIC” PITTING EDEMA OF

CRPS I (RSD)

Pitting

Edema

“CLASSIC” MOTTLED SKIN OF

CRPS I (RSD)

Mottled skin

Not RSD- Residual After Twisted Ankle

Note: Stocking

distribution of swelling

and edema. No

mechanical nor thermal

allodynia. 3 + pitting

edema. Marked bruising

and discoloration.

Tender over 4th and 5th

metatarsal.

Not RSD (CRPS I)-Pre-Op Skin Discoloration

Not RSD-Burning pain was in the top of

the foot, shin, and sole of foot after

severe auto accident, requiring L knee

replacement. Negative bone scan,

negative Indium scan, sed rate not

elevated, no thermal nor mechanical

allodynia, pain was not circumferential.

Pain was in distribution of tibial nerve,

and superficial peroneal nerve, and

100% relief with tibial nerve blocks, and

superficial peroneal nerve blocks.

Not RSD (CRPS I)- Post-Op

Not RSD-Burning pain

was in the top of the

foot, shin, and sole of

foot after severe auto

accident, requiring L

knee replacement. 100%

relief with left tibial,

common peroneal and

saphenous nerve

decompression, with

improved skin

coloration, bilaterally.Tibial Decompression

THERMOGRAPHY OF CRPS I (RSD)

The left leg is so cold

it doesn’t show.

BONE SCAN OF CRPS I (RSD)

Localized

inflammation

of gout

Diffuse

hyperemia of

CRPS I

“CLASSIC” SHINY SKIN AND NAIL

GROWTH OF STAGE III CRPS I (RSD)

CRPS I (RSD) vs CRPS II (CAUSALGIA)

CRPS I (RSD)

• Circumferential in distribution

• Good response to sympathetic blocks

• No response to nerve blocks

• Both thermal and mechanical allodynia

CRPS II (CAUSALGIA)

• Follows discrete nerve

distribution

• Variable response to

sympathetic blocks

• Responds well to

nerve blocks

• Mechanical allodynia

CRPS I (RSD) vs Nerve Entrapment

CRPS I (RSD)

• Circumferential in distribution

• Good response to sympathetic blocks

• No response to peripheral nerve blocks

• Both thermal and mechanical allodynia

Nerve Entrapment

• Follows discrete nerve

distribution

• Variable response to

sympathetic blocks

• Responds well to

peripheral nerve

blocks

• Mechanical allodynia

DIFFERENTIAL DIAGNOSIS OF CRPS

I (RSD) (Hendler, Pan Arab Journal of Neurosurgery, ’02)

• N = 38 patients referred to Mensana Clinic with the diagnosis of CRPS I (RSD).

• 1/38 (3%) had pure CRPS I (RSD) without any other illness.

• 10/38 (26%) had CRPS I (RSD) with nerve entrapment.

• 37/38 (97%) had nerve entrapment confirmed by electrophysiological (CPT) testing, and nerve blocks but missed by the referring doctor.

• 27/38 (71%) had no signs or symptoms compatible with CRPS I (RSD). They had just nerve entrapment(s).

• Prior to admission, only 7/38 (21%) patients had bone scans and only 22/38 (58%) had sympathetic blocks.

Missed Diagnoses-CRPS I(Hendler, N, Differential Diagnosis of CRPS I, Pan Arab Journal of

Neurosurgery, ’02)

• Of the 38 patients referred to Mensana Clinic with the diagnose of RSD (CRPS I):

• 42 % never had a sympathetic block.

• 79 % never had a bone scan.

• 100% never have a peripheral nerve block.

• 71% had pain in a peripheral nerve distribution, not circumferentially.

• The word “allodynia” was not found in 100% of the charts.

Discharge Diagnosis in Patients From

Mensana Clinic, referred with only CRPS I(Hendler, N, Differential Diagnosis of CRPS I, Pan Arab Journal of

Neurosurgery, ’02)

• Discharge Diagnosis

• N =10 - CRPS I

• N = 2 - CRPS II

• N = 9 - Disrupted Disc

• N = 37 - Nerve entrapments

• N = 9 - Radiculopathy

• N = 16 - Thoracic Outlet

Testing Done in Patients (number done) From

Mensana Clinic, referred with only CRPS I(Hendler, N, Differential Diagnosis of CRPS I, Pan Arab Journal of

Neurosurgery, ’02)

• Test # of pts # of tests/pt + tests finding*

• Sympathetic blocks 11 pts (1-5) 10/11

• Bone Scans 38 pts (1-1) 11/38

• Phentolamine I.V. 7 pts (1-3) 4/7

• EMG/NCV 38 pts (1-2) 37/38

• Peripheral N. block 35 pts (1-6) 35/35

• Root blocks 10 pts (3-10) 9/10

• Provocative discog. 10 pts (1-3) 9/10

• Dopplers of arms 17 pts (1-2) 16/17

* not published

CRPS I (RSD) PRESENTS WITH A COLD LIMB, BUT NERVE

INJURIES MAY ALSO BE COLD(Uematsu, Hendler,Hungerford, Long and Ono, Electromyogr. Clin. Neurophysiol.

#21, pp165-182, 1981) N = 803 cases

Thermography and Electromyography in the

Differential Diagnosis of Chronic Pain Syndromes

and Reflex Sympathetic Dystrophy

• Uematsu, Hendler, Hungerford, Long and Ono, Electromyogr Clin. Neurophysiology, ’81

• Review of 803 patients with chronic limb and axial pain.

• 431 had abnormal skin (>1 C) temperature in the affected limb.

• 140 had increase temperature: 291 had lower temperature.

• In 73 cases of patients with abnormal neurological examination, 89% of patients had thermography abnormalities > 1 C.

• In 56 cases with abnormal EMG/NCV, 89% also had thermography abnormalities > 1 C, 42 % > 2 C.

• In 42 patients with RSD, 92 % had thermography abnormalities >1 C, 67% > 2 C.

Degree of Coldness in Limb with

CRPS I Measured by Thermography

1-1.9 C

2-2.9 C

> 3 C

Degree of coldness, measured by

thermography, in a limb with nerve

injury, confirmed by EMG/NCV

1-1.9 C

2-2.9 C

> 3 C

Hendler Alcohol Drop and Swipe Test(Hendler, Complex Regional Pain Syndrome I and II, Chapter 20, in Pain

Management, Edited by Richard Weiner, Ph.D, CRC Press, 2002)

• Squeeze an alcohol swab, and let a drop fall on

the affected area.

• If the patient immediately responds with severe

pain, this is thermal allodynia.

• Let the alcohol remain on the foot for 2 minutes. If

there is pain, this is chemical allodynia.

• Use the swab and gently swipe the affected area.

• Immediate pain is mechanical allodynia.

TESTS YOU CAN DO IN YOUR OFFICE(Hendler, Complex Regional Pain Syndrome I and II, Chapter 20, in Pain

Management, Edited by Richard Weiner, Ph.D, CRC Press, 2002)

• Interpretation of the Hendler Alcohol Drop and Swipe Test: A patient should have both thermal and mechanical allodynia to have CRPS I (RSD).

• Just mechanical allodynia suggests nerve entrapment or causalgia or radiculopathy.

• Just thermal or chemical allodynia suggests CRPS I (RSD).

• If Tinel is + in sural, tibial, superficial, deep peroneal ulnar, or radial nerve reproduces pain, block this nerve.

• If a nerve block gives total relief, then the diagnosis is nerve entrapment not CRPS I (RSD).

OUTSIDE LABORATORY STUDIES YOU CAN

ORDER WHILE WAITING FOR THE

CONSULTANT TO SEE PATIENT

• A bone scan can be a helpful diagnostic test, but

varies over the stages of the disease.

• An effective sympathetic block should warm the

limb. When the limb is warm, a patient with CRPS I

(RSD) will have 100% relief, for 2-6 hours.

• EMG/NCV measures only A beta sensory fibers and

motor fibers, but not C & A delta fibers.

• Current perception threshold measures A beta, A

delta and C sensory nerve fibers.

WHERE TO REFER THE PATIENT

AND WHAT YOU SHOULD EXPECT

• Refer the patient to a multi-disciplinary pain diagnostic

and treatment center, not a monomodal center (just

blocks, just medicine, etc).

• The center should do a bone scan and CPT (next page)

• No more than 6 sympathetic blocks should be done.

The limb must become warm in response to the block.

During the time the limb is warm, the patient should

experience 100% relief of all pain. Blocks last 2-6 Hrs.

• Nerve blocks should be done if the sympathetic block

does not produce 100% relief when the limb is warm.

• The treating doctor has an obligation to monitor the

progress of the patient.

Painless Electrodiagnostic Current Perception Threshold and

Pain Tolerance Threshold in CRPS Subjects and Healthy

Controls: A Multicenter Study- Texas Tech, Stanford, Mensana Clinic,

Mayo Clinic, Cleveland Clinic, Johns Hopkins, Vanderbilt, UC-SD, Uni. of

Texas, (P. Raj, H. Chado, R. Dotson, N. Hendler, et al, Pain Practice, 2001)

• CPT/PTT uses A.C. sinusoid waveforms at 5 Hz, 250 Hz, and

2,000 Hz (2 kHz), for C, A delta, A beta sensory fiber testing

respectively.

• Current Perception Threshold (CPT) is the threshold of feeling

electrical current. Early nerve entrapments have low CPT

(hyperalgesia), later, high CPT (hypoalgesia)

• Pain Tolerance Threshold (PTT) is the maximum amount of pain

from the current tolerated by the patient.

• In normal patients, non-nerve PPT is higher than CPT

• In CRPS I (RSD) patients, PPT is close to CPT, which gives

objective confirmation of clinical mechanical allodynia.

EXPECTED TREATMENT PROTOCOLS

• High dose steroid and exercise for 2-4 weeks.

• Ca++ blocking agents and phenoxybenzamine

• Use Anti-convulsants such as Neurontin 300mg qid up to 900 mg qid. Add Topamax if needed.

• Use narcotics if needed, and titrate according to response (5th vital sign -JCAHO).

• Use tricyclic antidepressants, not SSRIs.

• If the first sympathetic block worked, get a series of 5 more sympathetic blocks.

• If sympathetic blocks provided 100% relief, but did not last, do a surgical sympathectomy.

CONCLUSIONS

• There is no way to predict who will develop CRPS I (RSD). Get early confirmation.

• The clinical presentation of CRPS I (RSD) is variable.

• The clinical stages are not temporal but symptom related.

• Early, accurate diagnosis is essential for successful treatment, before it progresses to the spinal cord level.

CONCLUSIONS (continued)

• CRPS I (RSD) is misdiagnosed 71% of the time. You should refer the patient only to an expert experienced with CRPS I (RSD).

• Early diagnosis of CRPS I (RSD) improves the treatment outcome.

• Essential features of CRPS I (RSD) are a positive bone scan, thermal and mechanical allodynia, circumferential pain, and total relief from effective sympathetic blocks

• For comprehensive information and a test to provide a proper diagnosis, see www.DiagnoseMyPain.com

The 6 blind wise men examining an elephant, in order to

describe it to their king. The king can visualize an elephant,

only by integrating all the descriptions.