Complex Regional Pain Syndrome (CRPS)

1. Complex Regional Pain Syndrome (CRPS) Katie Golden

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

3. 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 treatment • suffered from • persistent pain • muscle contracture • and inability to flex or extend his arm.

4. 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

5. CRPS I • Subdivided into 3 stages • Acute stage (Stage 1 - Usually warm phase of 1-3 months) • Changes in skin temperature, switching between warm or cold • Faster growth of nails and hair • Muscle spasms and joint pain • Severe burning, aching pain that worsens with the slightest touch or breeze • Skin 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 skin • Nails that are cracked and break more easily • Pain that is becoming worse • Slower hair growth • Stiff 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 wasting • Pain in the entire limb

6. Common Characteristic Features • Spontaneous pain • Hyperalgesia • Impairment of motor function • Swelling • Changes in sweating • Vascular abnormalities in a single extremity • Discoloration of skin • An overt nerve injury is not detectable: • Various sensory symptoms have been observed. • Allodynia (mechanical and thermal) • Hyperalgesia (mechanical and thermal) • Hyperpathia • Hypo-esthesia • Hypothermesthesia • Proprioception 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

9. Causes • Trauma • (eg, sprain, dislocations, fractures, surgery, burns, crash injury) • Neurologic disorders • (eg, stroke, tumor, syringomyelia) • Herpes zoster infection • Myocardial infarction • Musculoskeletal disorder • (shoulder rotator cuff injury) • Malignancy • Spontaneous/idiopathic

10. 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 temperature • Thermography - 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 RSD • Quantitative 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.

11. Treatment and Management • Use of drugs, sympathetic blocks, and psychotherapy helps to achieve good pain control during PT. • Functional Restoration: Physical Therapy, Occupational Therapy • Tx myofascial pain with massage and myofascial release • Stellate (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 effect • Somatic 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) • Ultrasonography • Superficial hot packs

12. Medications • Opioid • High 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)

13. Medications Continued • Anticonvulsants • Pregabalin (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 relief • Other Alternatives: • Corticosteroid • mexiletine (orally active class Ib anti-arrhythmic agent) • nifedipine (calcium channel blocker) • propranolol (beta blocker) • phenoxybenzamine (alpha blocker) • clonidine (alpha2-adrenergic agonist) • Lidoderm 5% patches

15. 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>.