Complex Regional Pain Syndrome (CRPS)

Katie Golden

True or False

Complex Regional Pain Syndrome is a relatively new disorder that only started presenting itself within the last 20 years.

False

Has been recognized since the Civil War when it was called causalgia, a name chosen to describe intense, burning extremity pain after an injury King Charles IX treated for smallpox by inducing bleeding with a lancet applied to the arm.

After this treatmentsuffered from

– persistent pain– muscle contracture– and inability to flex or extend his arm.

Two Forms

CRPS I or reflex sympathetic dystrophy (RSD): occurs after an illness or injury that didn't directly damage the nerves in your affected limb

CRPS II or causalgia: with obvious nerve lesions

CRPS I

Subdivided into 3 stagesAcute stage (Stage 1 - Usually warm phase of 1-3 months)

Changes in skin temperature, switching between warm or coldFaster growth of nails and hairMuscle spasms and joint painSevere burning, aching pain that worsens with the slightest touch or breezeSkin that slowly becomes blotchy, purple, pale, or red; thin and shiny; swollen; more sweaty

Dystrophic phase (Stage 2-usually last 3-6 months)- Vasomotor instability for several months

Continued changes in the skinNails that are cracked and break more easilyPain that is becoming worseSlower hair growthStiff joints and weak muscles

Atrophic phase (Stage 3 - Usually cold extremity with atrophic changes. Can see permanent change)

Limited movement in limb because of tightened muscles and tendons (contracture)Muscle wastingPain in the entire limb

Common Characteristic Features

Spontaneous painHyperalgesiaImpairment of motor functionSwellingChanges in sweatingVascular abnormalities in a single extremityDiscoloration of skinAn overt nerve injury is not detectable:

Various sensory symptoms have been observed.Allodynia (mechanical and thermal)Hyperalgesia (mechanical and thermal)HyperpathiaHypo-esthesiaHypothermesthesiaProprioception and anesthesia dolorosa (sensibility to touch is absent, while severe pain is present in the anesthetic area)Dissociated sensory pattern (on rare occasions)

Changes in the growth pattern of hair or nails on the affected limb

Causes

Trauma (eg, sprain, dislocations, fractures, surgery, burns, crash injury)

Neurologic disorders (eg, stroke, tumor, syringomyelia)

Herpes zoster infectionMyocardial infarctionMusculoskeletal disorder

(shoulder rotator cuff injury)MalignancySpontaneous/idiopathic

Workup

No diagnostic criteria have been accepted uniformly for RSD Studies should be performed to id precipitating causes

Radiographic films may show patchy peri-articular demineralization within 3-6 weeks.  3-phase bone scan often is considered sensitive and specific, particularly in the early phase (< 20 weeks) of the syndrome

The most suggestive and sensitive findings on bone scan include diffuse increased activity, with juxta-articular accentuation uptake on the delayed images (phase 3) Phases 1 and 2 are less sensitive and specific for RSD

Imaging studies have shown to not be reliable screening tests in the differentiation between normal posttraumatic changes and those changes seen in CRPS Skin temperatureThermography - This test demonstrates limb temperature differences quantitatively, but it is nonspecific Sweat test - The sympathetic skin response (SSR) provides useful information on sudomotor dysfunction in patients with RSDQuantitative sudomotor axon reflex test (QSART)Chemical sweat test - This uses agents such as ninhydrin, cobalt blue, or starch iodine.Testing sweat output - In QSART, the stimulated sweat output is greater and is prolonged when sympathetic hyperfunction is present.Results of electromyography (EMG) and nerve conduction studies (NCS) typically are within the reference range in RSD Single-fiber EMG examination also shows no definite abnormalities Laser Doppler imaging, with appropriate stressors, provides a simple, fast, noninvasive, and painless method for the study of segmental autonomic function.

Treatment and Management

Use of drugs, sympathetic blocks, and psychotherapy helps to achieve good pain control during PT. Functional Restoration: Physical Therapy, Occupational TherapyTx myofascial pain with massage and myofascial releaseStellate (cervicothoracic) ganglion block is recommended Percutaneous lumbar sympathetic plexus catheter placement usually provides short-term pain relief in most patients and may have some long-term effectSomatic block- continuous epidural infusion with different variants of brachial plexus blocks, includes

axillary, supraclavicular, or infraclavicular approach Localized extremity pain may be relieved by a dorsal column stimulator A spinal cord stimulator (SCS) can be an effective treatment for the pain of RSD, including recurrent pain after ablative sympathectomy Intrathecal infusion Sympathectomy Transcutaneous electrical nerve stimulation (TENS) UltrasonographySuperficial hot packs

Medications

OpioidHigh doses of tramadol may provide effective and safe relief in neuropathic pain, including allodynia

Nonopioid analgesics (eg, NSAIDs, acetaminophen)Antidepressant medications play a major role in treatment of neuropathic pain.

Tricyclic antidepressants:Amitriptyline (Elavil)Imipramine (Tofranil)Doxepin (Sinequan)Clomipramine (Anafranil)Nortriptyline (Pamelor)

Selective serotonin reuptake inhibitor (SSRI) antidepressants:Paroxetine (Paxil)Fluoxetine (Prozac)Sertraline (Zoloft)Escitalopram (Lexapro)

Other antidepressants:Nefazodone (Serzone)Venlafaxine (Effexor)Duloxetine (Cymbalta)Bupropion (Wellbutrin)

Medications Continued

AnticonvulsantsPregabalin (Lyrica)Gabapentin (Neurontin)carbamazepine, phenytoin, sodium valproate, clonazepam, topiramate, lamotrigine

N -methyl-D-aspartate (NMDA) – receptor antagonists, including ketamine and dextromethorphan, may have potential as co-analgesics when used in combination with opioids. Benzodiazepines, baclofen, and tizanidine may be helpful in decreasing spasm and providing pain reliefOther Alternatives:

Corticosteroidmexiletine (orally active class Ib anti-arrhythmic agent)nifedipine (calcium channel blocker)propranolol (beta blocker)phenoxybenzamine (alpha blocker)clonidine (alpha2-adrenergic agonist)

Lidoderm 5% patches

Resources

Board, A.D.A.M. Editorial. Complex Regional Pain Syndrome. U.S. National Library of Medicine, 16 Feb. 2012. Web. 01 Oct. 2012. <http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0004456/>. Complex Regional Pain Syndrome in Emergency Medicine Treatment & Management." Complex Regional Pain Syndrome in Emergency Medicine Treatment & Management. N.p., n.d. Web. 01 Oct. 2012. <http://emedicine.medscape.com/article/793370-treatment>. "Physical Medicine and Rehabilitation for Complex Regional Pain Syndromes Follow-up."Physical Medicine and Rehabilitation for Complex Regional Pain Syndromes Follow-up. N.p., n.d. Web. 29 Sept. 2012. <http://emedicine.medscape.com/article/328054-followup>. Staff, Mayo Clinic. "Definition." Mayo Clinic. Mayo Foundation for Medical Education and Research, 31 Mar. 2011. Web. 01 Oct. 2012. <http://www.mayoclinic.com/health/complex-regional-pain-syndrome/DS00265/DSECTION%3Dtreatments-and-drugs>.