Complex Regional Pain Syndrome (CRPS): Difference between revisions

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<div class="noeditbox">Welcome to [[PPA Pain Project]]. This page is being reviewed and updated by participants of a project to populate the Pain section of Physiopedia. &nbsp;The project is supervised and co-ordinated by the [[The Physiotherapy Pain Association]].
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*Please do not edit unless you are involved in this project, but please come back in the near future to check out new information!! &nbsp;
'''Original Editors ''' - [[User:Katelyn Koeninger|Katelyn Koeninger]] and [[User:Kristen Storrie|Kristen Storrie]] [[Pathophysiology of Complex Patient Problems|from Bellarmine University's Pathophysiology of Complex Patient Problems project]] and [[User:Yves Hubar|Yves Hubar]]  
*If you would like to get involved in this project and earn accreditation for your contributions, [mailto:[email protected] please get in touch]!
</div> <div class="editorbox">
'''Original Editors ''' - [[User:Yves Hubar|Yves Hubar]]  


'''Top Contributors''' - {{Special:Contributors/{{FULLPAGENAME}}}} &nbsp;
'''Top Contributors''' {{Special:Contributors/{{FULLPAGENAME}}}}
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== Search Strategy  ==


Literature was found on pubmed and the vub v-spaces system.<br>  
== Introduction ==
<u>C</u>omplex <u>R</u>egional <u>P</u>ain <u>S</u>yndrome (CRPS) is a term for a complex pain disorder characterised by continuing (spontaneous and/or evoked) regional pain that is seemingly disproportionate in time or degree to the usual course of any known trauma or lesion. <ref name=":33" /> Specific clinical features include [[allodynia]], hyperalgesia, sudomotor and vasomotor abnormalities, and trophic changes. 


== Definition/Description  ==
CRPS has a multifactorial pathophysiology involving pain dysregulation in the [[Sympathetic Nervous System|sympathetic]] and [[Central Nervous System Pathways|central nervous systems]], and possible genetic, inflammatory, and psychological factors.


Many names have been used to describe this syndrome such as; Reflex Sympathetic Dystrophy, causalgia, algodystrophy, Sudeck’s atrophy, neurodystrophy and post-traumatic dystrophy. To standardise the nomenclature, the name complex regional pain syndrome was adopted in 1995 by the International Association for the Study of Pain (IASP).<ref name=":2">Tran Q. [https://pubmed.ncbi.nlm.nih.gov/20054678/ Treatment of complex regional pain syndrome: a review of the evidence.] Can J Anesth.  2010 Feb;57(2):149-66.</ref>


== Classification and Phenotypes ==
CRPS is commonly subdivided into '''Type I''' and '''Type II''' CRPS. Type I occurs in the absence of major nerve damage (minor nerve damage may be present), while Type II occurs following major nerve damage.<ref name=":0">Dey DD, Schwartzman RJ. [https://www.statpearls.com/articlelibrary/viewarticle/19793/ Complex Regional Pain Syndrome (Reflex Sympathetic Dystrophy).] StatPearls;2012:07-6. </ref> Despite this distinction, there is a large overlap in clinical features and the primary diagnostic criteria are identical, and the classification therefore may have little clinical importance.<ref name=":33" /> <ref name=":3">Baron R, Wasner G. [https://pubmed.ncbi.nlm.nih.gov/11252145/ Complex regional pain syndromes.] Curr Pain Headache Rep. 2001 Apr;5(2):114-23. </ref><ref name=":26">O'Connell NE, Wand BM, McAuley J, Marston L, Moseley GL. [https://pubmed.ncbi.nlm.nih.gov/23633371/ Interventions for treating pain and disability in adults with complex regional pain syndrome.] Cochrane Database Syst Rev. 2013 Apr 30;2013(4):CD009416.  </ref><ref name=":8">Wasner G, Schattschneider J, Heckmann K, Maier C, Baron R. [https://pubmed.ncbi.nlm.nih.gov/11222458/ Vascular abnormalities in reflex sympathetic dystrophy (CRPS I): mechanisms and diagnostic value.] Brain. 2001 Mar;124(Pt 3):587-99.  </ref><ref name=":9">Jänig W, Baron R. [https://pubmed.ncbi.nlm.nih.gov/12269546/ Complex regional pain syndrome is a disease of the central nervous system.] Clin Auton Res. 2002 Jun;12(3):150-64. </ref>


Complex regional pain syndrome (CRPS) is a term for a variety of clinical conditions characterized by chronic persistent pain. It is a disease that may develop after a limb trauma.
Three stages (stage I - acute up to 3 months, stage II - dystrophic 3-6- months after onset, stage III  - atrophic > 6 months) of CRPS progression have been proposed by Bonica in the past, but the existence of these stages has been suggested as unsubstantiated. <ref>[https://pubmed.ncbi.nlm.nih.gov/11790474/ Bruehl S, Harden RN, Galer BS, Saltz S, Backonja M, Stanton-Hicks M. Complex regional pain syndrome: are there distinct subtypes and sequential stages of the syndrome?] Pain. 2002 Jan;95(1-2):119-24. </ref><ref>Bruehl S, Harden RN, Galer BS, Saltz S, Backonja M, Stanton-Hicks M. [https://pubmed.ncbi.nlm.nih.gov/11790474/ Complex regional pain syndrome: are there distinct subtypes and sequential stages of the syndrome?] Pain. 2002 Jan;95(1-2):119-24.</ref> It is however possible for CRPS subtypes to evolve over time, currently referred to as "'''warm CRPS"''' (warm, red, dry and oedematous extremity, inflammatory phenotype) and "'''cold CRPS"''' (cold, blue or pale, sweaty and less oedematous, central phenotype). <ref>Bruehl S, Maihöfner C, Stanton-Hicks M, Perez RS, Vatine JJ, Brunner F, Birklein F, Schlereth T, Mackey S, Mailis-Gagnon A, Livshitz A, Harden RN. [https://pubmed.ncbi.nlm.nih.gov/27023422/ Complex regional pain syndrome: evidence for warm and cold subtypes in a large prospective clinical sample.] Pain. 2016 Aug;157(8):1674-81.</ref> Both of these subtypes present with comparable pain intensity. Warm CRPS is by far the most common in early CRPS, and cold CRPS tends to have a worse prognosis and more persistent symptomatology.<ref name=":33" />
<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref>
This appears mostly in 1 or more limbs, usually in the arms or legs. We can say a CRPS is a regional posttraumatic neuropathic pain problem.
<ref>RHO, R. e.a., Concise Review for Clinicians: Complex Regional Pain Syndrome. Mayo Foundation for Medical Education and Research, 2002. (level of evidence 3A)</ref>
Neuropathic pain disorders are a disproportionate consequence of painful trauma or nerve lesion.
<ref>WASNER, G., e.a., Vascular abnormalities in reflex sympathetic dystrophy (CRPS I): mechanisms and diagnostic value. Oxford University Press, 2001. (level of evidence 3A)</ref>


Dimova and associates <ref>Dimova V, Herrnberger MS, Escolano-Lozano F, Rittner HL, Vlckova E, Sommer C, Maihöfner C, Birklein F. Clin[https://pubmed.ncbi.nlm.nih.gov/31874923/ ical phenotypes and classification algorithm for complex regional pain syndrome.] Neurology. 2020 Jan 28;94(4):e357-e367. </ref>recentrly proposed another classification based on the findings of the neurological examination. The first group of patients presents with a central phenotype, with motor signs, allodynia, and glove/stocking-like sensory deficits. The second cluster represents a pheripheral inflammation phenotype, involving edema, skin color changes, skin temperature changes, sweating, and trophic changes. The third group has a mixed presentation. 


CRPS is subdivided into type I and type II CRPS.
As noted from above, although classification for CRPS shows some variability, there is agreement on mechanisms of central and inflammatory origin. Further research is needed to reach clusters that lead to valid and effective treatment decisions.  


In the literature, there are a lot of names used to describe this syndrome such as ‘‘Reflex Sympathetic Dystrophy’’, ‘‘causalgia’’, ‘‘algodystrophy’’, ‘‘Sudeck’s atrophy’’, ‘‘neurodystrophy’’, and ‘‘post-traumatic dystrophy’’. To standardize the nomenclature, the name ‘complex regional pain syndrome’ was adopted in 1995 by the ‘International Association for the Study of Pain’ (IASP).<ref>TRAN, Q., e.a., Treatment of complex regional pain syndrome: a review of the evidence. Canadian Anesthesiologists’ Society, 2010. (level of evidence 1A)</ref><br>
== Epidemiology ==


<br>
=== '''Incidence and Prevalence''' ===
CRPS incidence appears to vary according to global location. For example, studies show that Minnesota has an incidence of 5.46 per 100,000 person-years for CRPS type I and 0.82 per 100,000 person-years for CRPS type II, whilst the Netherlands in 2006 had 26.2 cases per 100,000 person-years. Research shows that CRPS is more common in females than males, with a ratio of 3.5:1.<ref name="goebel">Goebel A. [https://pubmed.ncbi.nlm.nih.gov/21712368/ Complex regional pain syndrome in adults.] Rheumatology (Oxford) 2011 Oct;50(10):1739-50.</ref> CRPS can affect people of all ages, including children as young as three years old and adults as old as 75 years, but typically is most prevalent in the mid-thirties. CRPS Type I occurs in 5% of all traumatic injuries, with 91% of all CRPS cases occurring after surgery.<ref name="turner">Turner-Stokes L, Goebel A. [https://pubmed.ncbi.nlm.nih.gov/22268318/ Complex regional pain syndrome in adults: concise guidance.] Clin Med (Lond) 2011 Dec;11(6):596-600.</ref>


== Clinically Relevant Anatomy  ==
=== '''Location''' ===
The location of CRPS varies from person to person, mostly affecting the extremities, occurring slightly more in the lower extremities (+/- 60%) than in the upper extremities (+/- 40%). It can also appear unilaterally or bilaterally.<ref name=":6">Sumitani M, Yasunaga H, Uchida K, Horiguchi H, Nakamura M, Ohe K, Fushimi K, Matsuda S, Yamada Y. [https://pubmed.ncbi.nlm.nih.gov/24369418/ Perioperative factors affecting the occurrence of acute complex regional pain syndrome following limb bone fracture surgery: data from the Japanese Diagnosis Procedure Combination database.] Rheumatology (Oxford). 2014 Jul;53(7):1186-93. </ref>


CRPS can take place in any body part, but often in the extremities. The wrist is most frequently affected after distal radial fractures.[5] It is a disorder with assorted clinical appearances and gravity of disease. Central and peripheral nervous system are connected through neural and chemical pathways, there is a direct control over the autonomic system. It is for this reason that there can be changes in the vasomotor and sudomotor without any impairment in the peripheral nervous system. Pain, heath and swelling are usually not located at the site of inciting injury and there may be no clear damage. Central sensitisation is seen as a main cause for developing CRPS. [6, 7]<br>
=== '''Prognosis''' ===
Approximately 15% of early CRPS (up to 6-18 months duration) fail to recover and early onset of cold CRPS predicts poor recovery.<ref name=":33" />
== Aetiology  ==


== Epidemiology /Etiology  ==
Complex regional pain syndrome can develop after the occurrence of different types of injuries, such as:


Complex regional pain syndrome can develop after different types of inciting injuries.<br>A few examples are:<br>● sprains and strains,<br>● post-surgical, <br>● fractures,<br>● contusions,<br>● crush injuries,<br>● nerve lesions,<br>● stroke.<br>Sometimes the inciting injury can occur spontaneously or can not be determined. <ref>ROSS A.H. et al., The Theoretical Basis for and Treatment of Complex Regional Pain Syndrome with Prolotherapy. Journal of Prolotherapy, 2010. (level of evidence 2C)</ref><ref>BARON, et al., Complex regional pain syndrome: mystery explained? The Lancet Neurology, 2003. (level of evidence 3B)</ref><ref>ALLEN, G., et al., Epidemiology of complex regional pain syndrome: a retrospective chart review of 134 patients. Pain,1999. (level of evidence 2B)</ref><ref>SUMITANI M., et al., Complex regional pain syndrome. Rheumatology, 2014. (level of evidence 2C)</ref><ref>JUOTTONEN, K., et al., Altered central sensorimotor processing in patients with complex regional pain syndrome. Pain, 2002. (level of evidence 5)</ref><ref>ATALA,  N.S., et al., Prednisolone in Complex Regional Pain Syndrome. Pain Physician, 2014. (level of evidence 2B)</ref> <br> Fifty-six percent of patients reported CRPS was due to an ‘on-the-job’ injury. The most common type of work-related injury occurred in service employments, such as in restaurants, bakeries and police offices.<ref>ALLEN, G., et al., Epidemiology of complex regional pain syndrome: a retrospective chart review of 134 patients. Pain,1999. (level of evidence 2B)</ref>
*Minor soft tissue trauma (sprains)
*Surgeries
*[[Fracture|Fractures]], especially following immobilisation
*Contusions
*Crush injuries  
*Nerve lesions  
*[[Stroke]]


The location of the CPRS varies from person to person. It often occurs in the extremities, a little bit more in the lower extremities (+/- 60%) than in the upper extremities (+/- 40%). It can also appear on the left and the right side and in both extremities.<ref>ROSS A.H. et al., The Theoretical Basis for and Treatment of Complex Regional Pain Syndrome with Prolotherapy. Journal of Prolotherapy, 2010. (level of evidence 2C)</ref><ref>ALLEN, G., et al., Epidemiology of complex regional pain syndrome: a retrospective chart review of 134 patients. Pain,1999. (level of evidence 2B)</ref><ref>SUMITANI M., et al., Complex regional pain syndrome. Rheumatology, 2014. (level of evidence 2C)</ref>
The onset is mostly associated with a trauma, immobilisation, injections, or surgery, but there is no relation between the grade of severity of the initial injury and the following syndrome. In 7% of cases there is no injury or surgery preceding the onset of CRPS.


Complex regional pain syndrome occurs regularly in young adults. It is more frequent in females than males.<ref>SRINIVASA N. et al., Complex Regional Pain Syndrome I (Reflex Sympathetic Dystrophy). American Society of Anesthesiologists, 2002. (level of evidence 3B)</ref><ref>SANDRONI, P., et al., Complex regional pain syndrome type I: incidence and prevalence in Olmsted county, a population-based study. Pain, 2003. (level of evidence 2B)</ref>  
A study found that excessive baseline pain (>5/10) in the week following wrist fracture surgery increases the risk of developing CRPS. <ref>Moseley GL, Herbert RD, Parsons T, Lucas S, Van Hilten JJ, Marinus J. Intense pain soon after wrist fracture strongly predicts who will develop complex regional pain syndrome: prospective cohort study. The Journal of Pain. 2014 Jan 1;15(1):16-23.</ref> A stressful life and other psychological factors may be potential risk factors that impact the severity of symptoms in CRPS. <ref name=":7">Raja SN, Grabow TS. [https://pubmed.ncbi.nlm.nih.gov/11981168/ Complex regional pain syndrome I (reflex sympathetic dystrophy).] Anesthesiology. 2002 May;96(5):1254-60.  </ref>There is however no compelling evidence that psychiatric disorders contribute to the development of CRPS. <ref name=":33" />  


The onset is mostly associated with a trauma in history, immobilization, injections or surgery. But there is no relation between the grade of severity of the initial injury and the following syndrome. A stressful life and other psychological factors may be potential risk factors that impact the severity of symptoms in CPRS.<ref>SRINIVASA N. et al., Complex Regional Pain Syndrome I (Reflex Sympathetic Dystrophy). American Society of Anesthesiologists, 2002. (level of evidence 3B)</ref>
== Pathophysiology  ==


<br>
[[Image:Teasdall et al-2.jpg|right|400px]]


<br>
Various mechanisms are at play in the development and maintenance of CRPS, including nerve injury, central and peripheral sensitisation, altered sympathetic function, inflammatory and immune factors, brain changes, genetic factors and psychological factors.<ref>Bruehl S. [https://rsds.insctest1.com/wp-content/uploads/2020/06/CRPS-Dr.-Stephen-Bruehl.pdf Complex regional pain syndrome.] Bmj. 2015 Jul 29;351.</ref> Little is however known about how these mechanisms interact and it is likely that the relative contribution of each mechanism varies between patients. <ref name=":5">Wen B, Pan Y, Cheng J, Xu L, Xu J. [https://pubmed.ncbi.nlm.nih.gov/37701560/ The Role of Neuroinflammation in Complex Regional Pain Syndrome: A Comprehensive Review.] J Pain Res. 2023 Sep 6;16:3061-3073.</ref>  


== Characteristics/Clinical Presentation<br> ==
CRPS usually follows trauma/surgery, and likely starts with normal peripheral nociceptive stimulation. Enhanced, altered and ongoing nociception can then lead to [[Peripheral Sensitisation|peripheral]] and [http://www.physio-pedia.com/Central_sensitisation central sensitisation] (CS), with the latter regarded as a prominent mechanism underlying CRPS.<ref name=":3" /><ref>Shipton E. [https://www.semanticscholar.org/paper/Complex-regional-pain-syndrome-%E2%80%93-Mechanisms%2C-and-Shipton/608d7751cf116f8167f905f451e020b8c14900a6 Complex regional pain syndrome – Mechanisms, diagnosis, and management.] Curr Anaesth Crit Care. 2009; 20:209-14. </ref>  


<br>
Sustained neuroinflammation has lately received attention as a key factor in the initiation and perpetuation of CRPS. <ref name=":5" /> Neuropeptides mediate the enhanced neurogenic inflammation and pain; they may activate microglia and astrocytes, resulting in a cascade of events that sensitise neurons and impact synaptic plasticity. <ref name=":5" /> Upregulated cytokines, secreted by keratinocytes, exacerbate this phenomenon. <ref name=":5" /> Immune cells may also modulate neuronal activity by releasing immunomodulatory factors. <ref name=":5" /> 


== Differential Diagnosis ==
Psychological factors could maintain CRPS by their impact on catecholamine release and kinesiophobia. The central and peripheral nervous systems are connected through neural and chemical pathways, and can have direct control over the autonomic nervous system. It is for this reason that there can be changes in vasomotor and sudomotor responses without any impairment in the peripheral nervous system. For a more detailed review of the underlying mechanisms at play, see this [https://rsds.insctest1.com/wp-content/uploads/2020/06/CRPS-Dr.-Stephen-Bruehl.pdf article] by Bruehl (2015).  


The differential diagnosis includes the direct effects of <ref>TURNER-STOKES, L., e.a., Complex regional pain syndrome in adults: concise guidance. Clinical Med, 2011. (level of evidence 5)</ref><ref>MCBRIDE, A., e.a., Complex Regional Pain Syndrome, Current Orthopaedics, 2005. (level of evidence 3A)</ref>
Treatment approaches are aimed at normalising afferent inputs and reversing secondary changes associated with immobilisation.  


:<br>● Bony or soft tissue injury<br>● Peripheral neuropathy, nerve lesions<br>● Arthritis<br>● Infection<br>● [http://www.physio-pedia.com/Compartment_Syndrome Compartment syndrome]<br>● Arterial insufficiency<br>● Raynaud’s Disease<br>● Lymphatic or venous obstruction<br>● [http://www.physio-pedia.com/Thoracic_Outlet_Syndrome Thoracic outlet syndrome]<br>● Gardner-Diamond Syndrome<br>● Erythromelalgia<br>● Self-harm or malingering<br>● Cellulitis<br>● Undiagnostic fracture
'''Figure 1.''' ''Nociceptive (painful) information is relayed through the dorsal horn of the spinal cord for processing and modulation before cortical evaluation.'' <ref>Teasdall R, Smith BP, Koman LA. [https://pubmed.ncbi.nlm.nih.gov/15062588/ Complex Regional Pain Syndrome (reflex sympathetic dystrophy).] Clin Sports Med. 2004 Jan;23(1):145-55. </ref>


<br>  
'''Video below:''' more on the pathophysiology underlying CRPS.<br>  


'''Diagnostic Procedures'''
{{#ev:youtube|v=l_yWmYcNFas|250}}


----
== Clinical Presentation  ==


The diagnosis of CRPS requires a complicated process due to the absence of a golden standard test for diagnosis.<ref>PEREZ, R., et al., Diagnostic criteria for CRPS I: Differences between patient profiles using three different diagnostic sets. European Journal of Pain, 2007. (level of evidence 2A)</ref><ref>ALBAZAZ, R. N., et al., Complex Regional Pain Syndrome: A review. Annals of Vascular Surgery Inc., 2008. (level of evidence 2A)</ref><ref>HARDEN, R. N., et al., Validation of proposed diagnostic criteria (the ‘‘Budapest Criteria”) for Complex Regional Pain Syndrome. International Association for the Study of Pain, 2010. (level of evidence 1C)</ref><ref>CHOI, E., et al., Interexaminer reliability of infrared thermography for the diagnosis of complex regional pain syndrome. Skin Research and Technology, 2013. (level of evidence 2B)</ref> There are some criteria for diagnosis of CRPS, known as the Budapest criteria, and until there is a golden standard these criteria must suffice.<ref>HARDEN, R. N., Commentary: The Diagnosis of CRPS: Are we there yet?. International Association for the Study of Pain, 2012. (level of evidence 1B)</ref> The Budapest criteria, also called the IASP clinical diagnostic criteria for complex regional pain syndrome are<ref>PEREZ, R., et al., Diagnostic criteria for CRPS I: Differences between patient profiles using three different diagnostic sets. European Journal of Pain, 2007. (level of evidence 2A)</ref><ref>ALBAZAZ, R. N., et al., Complex Regional Pain Syndrome: A review. Annals of Vascular Surgery Inc., 2008. (level of evidence 2A)</ref><ref>HARDEN, R. N., et al., Validation of proposed diagnostic criteria (the ‘‘Budapest Criteria”) for Complex Regional Pain Syndrome. International Association for the Study of Pain, 2010. (level of evidence 1C)</ref><ref>HARDEN, R. N., Commentary: The Diagnosis of CRPS: Are we there yet?. International Association for the Study of Pain, 2012. (level of evidence 1B)</ref><ref>WASNER, G., et al., Complex regional pain syndrome - diagnostic, mechanisms, CNS involvement and therapy. International Spinal Cord Society, 2003. (level of evidence 2A)</ref><ref>HODGE, S., et al., Complex Regional Pain Syndrome: The Anatomy Of A Controversy. Anatomy For Litigators: complex regional pain syndrome, p. 163-167. (level of evidence 2A)</ref>:<br>● Constant pain, higher than the normally perceived pain <br>● Minimum one symptom in three of the following four symptom categories must be reported:<br>○ Vasomotor: temperature asymmetry and/or skin color changes/asymmetry<br>○ Sensory: hyperalgesia and/or allodynia<br>○ Sudomotor/edema: changes in sweating <br>○ Motor/trophic: smaller range of motion,motor dysfunction and/or changes in hair, nails and skin<br>● In addition to these symptoms the patient must also show signs that he will develop symptoms in at least two symptom categories<br>● No other illness could explain the set of symptoms the patient is showing. <br> CRPS diagnosis is mainly based on history, clinical examination, and some supportive investigations, just like:<br> <br>1. Infrared thermography<br>Infrared thermography (IRT) is an effective mechanism to find significant asymmetry in temperature between both limbs by determining if the affected side of the body shows vasomotor differences in comparison to the other side. It is reported having a sensitivity of 93% and a specificity of 89%.<ref>ALBAZAZ, R. N., et al., Complex Regional Pain Syndrome: A review. Annals of Vascular Surgery Inc., 2008. (level of evidence 2A)</ref> This test is hard to obtain so it is not often used for diagnosis of CRPS.<ref>PEREZ, R., et al., Diagnostic criteria for CRPS I: Differences between patient profiles using three different diagnostic sets. European Journal of Pain, 2007. (level of evidence 2A)</ref><ref>ALBAZAZ, R. N., et al., Complex Regional Pain Syndrome: A review. Annals of Vascular Surgery Inc., 2008. (level of evidence 2A)</ref><ref>CHOI, E., et al., Interexaminer reliability of infrared thermography for the diagnosis of complex regional pain syndrome. Skin Research and Technology, 2013. (level of evidence 2B)</ref><br> <br>2. Sweat Testing<br>To determine if the patient sweats abnormally the amount of sweat that he produces can be measured. Q-sweat is an adequate instrument to measure sweat production. The sweat samples should be taken from both sides of the body at the same time.<ref>BARON, R., Complex regional pain syndromes. Curr Pain Headache Rep., 2001. (level of evidence 2A)</ref><ref>ALBAZAZ, R. N., et al., Complex Regional Pain Syndrome: A review. Annals of Vascular Surgery Inc., 2008. (level of evidence 2A)</ref><ref>CHEMALI, K., et al., α-adrenergic supersensitivity of the sudomotor nerve in complex regional pain syndrome. Annals of Neurology, 2001. (level of evidence 2B)</ref><br> <br>3. Radiographic Testing<br>Irregularities in the bone structure of the affected side of the body can become visible with the use of [http://www.physio-pedia.com/X-Rays X-rays]. If the X-ray shows no sign of osteoporosis, CRPS can be excluded if the patient is an adult.<ref>BARON, R., Complex regional pain syndromes. Curr Pain Headache Rep., 2001. (level of evidence 2A)</ref><ref>ALBAZAZ, R. N., et al., Complex Regional Pain Syndrome: A review. Annals of Vascular Surgery Inc., 2008. (level of evidence 2A)</ref><ref>HODGE, S., et al., Complex Regional Pain Syndrome: The Anatomy Of A Controversy. Anatomy For Litigators: complex regional pain syndrome, p. 163-167. (level of evidence 2A)</ref> 4. Three-phase bone scan<br>With the use of technetium Tc 99m-labeled bisophosphonates increase in bone metabolism can be shown. Higher uptake of the substance means increased bone metabolism which means the body part could be affected.<ref>ALBAZAZ, R. N., et al., Complex Regional Pain Syndrome: A review. Annals of Vascular Surgery Inc., 2008. (level of evidence 2A)</ref><ref>HODGE, S., et al., Complex Regional Pain Syndrome: The Anatomy Of A Controversy. Anatomy For Litigators: complex regional pain syndrome, p. 163-167. (level of evidence 2A)</ref> <br> <br>5. Bone densitometry<br>An affected limb often shows less bone mineral density and a change in the content of the bone mineral. During treatment of the CPRS the state of the bone mineral will improve. So this test can also be used to determine if the patient’s treatment is effective.<ref>ALBAZAZ, R. N., et al., Complex Regional Pain Syndrome: A review. Annals of Vascular Surgery Inc., 2008. (level of evidence 2A)</ref><br> <br>6. [http://www.physio-pedia.com/MRI_Scans Magnetic resonance imaging (MRI)]<br>MRIs are useful to detect periarticular marrow edema, soft tissue swelling and joint effusions. And in a later stage atrophy and fibrosis of periarticular structures can be detected. But these symptoms are not exclusively signs of CRPS.<ref>BARON, R., Complex regional pain syndromes. Curr Pain Headache Rep., 2001. (level of evidence 2A)</ref><ref>ALBAZAZ, R. N., et al., Complex Regional Pain Syndrome: A review. Annals of Vascular Surgery Inc., 2008. (level of evidence 2A)</ref><ref>HODGE, S., et al., Complex Regional Pain Syndrome: The Anatomy Of A Controversy. Anatomy For Litigators: complex regional pain syndrome, p. 163-167. (level of evidence 2A)</ref><br> <br>7. Sympathetic Blocks<br>If the patient shows vasomotor or sudomotor dysfunction and severe pain, blocking the sympathetic nerves proves to be an effective technique to evaluate if the sympathetic nervous system is causing the pain to remain. This technique requires local anesthetic or ablation and is successful if at least 50% of the pain is reduced.<ref>ALBAZAZ, R. N., et al., Complex Regional Pain Syndrome: A review. Annals of Vascular Surgery Inc., 2008. (level of evidence 2A)</ref>
CRPS is clinically characterised by sensory, autonomic, and motor disturbances. The table below shows an overview of these characteristics. <ref name=":2" /> <ref name=":3" /> <ref name=":10">Juottonen K, Gockel M, Silén T, Hurri H, Hari R, Forss N. [https://pubmed.ncbi.nlm.nih.gov/12127033/ Altered central sensorimotor processing in patients with complex regional pain syndrome.] Pain. 2002 Aug;98(3):315-323. </ref> <ref name=":8" /> <ref name=":9" /> <ref>Galer BS, Henderson J, Perander J, Jensen MP. [https://pubmed.ncbi.nlm.nih.gov/11027911/ Course of symptoms and quality of life measurement in Complex Regional Pain Syndrome: a pilot survey.] J Pain Symptom Manage. 2000 Oct;20(4):286-92. </ref>
{| class="wikitable"
|+Features of CRPS
!'''Sensory disturbances'''
![[Allodynia]] and hyperalgesia
Hypoesthesia; Strange, disfigured or dislocated feeling in the limb<ref name="goebel" />
|-
|'''Autonomic and inflammatory components'''
|Swelling and oedema<ref name="goebel" />
Hyperhidrosis; changes in sweating
Abnormal skin blood flow
Temperature changes<ref name="goebel" />
Colour changes (redness or pale)
|-
|'''Trophic changes'''
|Thick, brittle, or rigid nails
Increased/decreased hair growth
Thin, glossy, clammy skin<ref name="goebel" />
Osteopenia (chronic stage)
|-
|'''Motor dysfunction'''
|Weakness of multiple muscles and atrophy <ref name="goebel" />
Inability to initiate movement of the extremity
Stiffness and reduced ROM
Tremor or dystonia
|-
|'''Pain'''
|Burning, deep, dull
Disproportionate
Spontaneous and/or triggered by movement, noise, pressure on joint
Pain may not be present in 7% of CRPS patients<ref name="goebel" />
|}
<br>Symptoms can spread beyond the area of the lesioned nerve in Type II. Ongoing neurogenic inflammation, vasomotor dysfunction, central sensitisation and maladaptive neuroplasticity contribute to the clinical phenotype of CRPS. <ref name=":8" /> <ref name=":6" />
== Associated Co-morbidities  ==


== Outcome Measures  ==
CRPS may also be associated with:


add links to outcome measures here (also see [[Outcome Measures|Outcome Measures Database]])
*Impaired microcirculation  <ref name=":11">Groeneweg G, Huygen F, Coderre T, Zijlstra F. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2758836/ Regulation of peripheral blood flow in Complex Regional Pain Syndrome: clinical implication for symptomatic relief and pain management.] BMC Musculoskelet Disord. 2009;10:116.</ref>
*[[Asthma]] <ref name="goebel" />
*[[Fracture|Fractures]] <ref name="Hooshmand">Hooshmand H, Phillips E. [https://www.rsdrx.com/Spread_of_CRPS.pdf Spread of complex regional pain syndrome.] Available from: https://www.rsdrx.com/Spread_of_CRPS.pdf [accessed 5/7/2023]</ref>
*[[Cellulitis]] <ref>Goebel A. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4590068/ Current Concepts in Adult CRPS. Rev Pain.] 2011 Jun; 5(2): 3–11.</ref>
*Conversion Disorder <ref>Popkirov S, Hoeritzauer I, Colvin L, Carson AJ, Stone J. [https://pubmed.ncbi.nlm.nih.gov/30355604/ Complex regional pain syndrome and functional neurological disorders - time for reconciliation.] J Neurol Neurosurg Psychiatry. 2019 May;90(5):608-14. </ref>
*[[Depression]]/Anxiety
*Lymphedema <ref name=":11" />
*Malignancy <ref>Mekhail N, Kapural L. [https://pubmed.ncbi.nlm.nih.gov/10998738/ Complex regional pain syndrome type I in cancer patients.] Curr Rev Pain. 2000;4(3):227-33. </ref>
*[[Migraine Headache|Migraines]] <ref name="goebel" />
*[[Osteoporosis]] <ref name="goebel" /><ref name="Hooshmand" />
*Autoimmune dysfunction <ref>Dirckx M, Schreurs M, de Mos M, Stronks D, Huygen F. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4337272/ The Prevalence of Autoantibodies in Complex Regional Pain Syndrome Type I.] Mediators Inflamm. 2015; 2015: 718201.</ref>


== Examination ==
== Differential Diagnosis ==


The original International Association for the Study of Pain criteria required only history and subjective symptoms for a diagnosis of CRPS. But recent consensus guidelines developed by experts have argued for the inclusion of objective findings. <ref>PENTLAND, B., e.a., Parkinsonism and dystonia. Neurological Rehabilitation, 1997. (level of evidence 2C)</ref> <br> <br>The examination of the affected limb should be done from the neck downwards. The examination should be carried out at rest, during activity, and during ambulation. <ref>SANDEEP, J., Complex Regional Pain Syndrome. Indian Journal of Plastic Surgery, 2011. (level of evidence 2A )</ref> <br> <br>During the physical examination, it is very important to investigate the sensory, motor and autonomic dysfunctions. <ref>PENTLAND, B., e.a., Parkinsonism and dystonia. Neurological Rehabilitation, 1997. (level of evidence 2C)</ref><ref>ROMMEL, e.a., Quantitative sensory testing, neurophysiological and psychological examination in patients with complex regional pain syndrome and hemisensory deficits. Ruhr-University, 2000. (level of evidence 1B)</ref><ref>SANDEEP, J., Complex Regional Pain Syndrome. Indian Journal of Plastic Surgery, 2011. (level of evidence 2A )</ref> <br> <br>1. Autonomic dysfunction<br>The majority of patients with CRPS have side-to-side differences in temperature of the limbs. The skin temperature depends of the chronicity of the disease. The temperature will increase in acute stages, this is most of the time in combination with a white or reddish skin with more swelling. The temperature will decrease in chronic stages. This is associated with bluish skin and more atrophy. <ref>FRONTERA, W, e.a., Essentials of Physical Medicine and Rehabilitation - Musculoskeletal disorders, pain and rehabilitation. Saunders Elsevier, 2002. (level of evidence 5)</ref> <br> <br>2. Motor dysfunction<br>Studies have shown that approximately 70% of the patients with CRPS show muscle weakness in the affected limb, exaggerated tendon reflexes or tremor, irregular myoclonic jerks, and dystonic muscle contractions. Muscle dysfunction often coincides with a loss of range of motion in the distal joints. <ref>SANDEEP, J., Complex Regional Pain Syndrome. Indian Journal of Plastic Surgery, 2011. (level of evidence 2A )</ref><br> <br>3. Sensory dysfunction<br>The distal ends of the extremities require more attention when examining a patient with CRPS. However, common findings of regional neuropathic and motor dysfunction have shown us that it is important to broaden the examination both proximally and contra laterally.<ref>FRONTERA, W, e.a., Essentials of Physical Medicine and Rehabilitation - Musculoskeletal disorders, pain and rehabilitation. Saunders Elsevier, 2002. (level of evidence 5)</ref><br> <br>Light touch, pinprick, temperature and vibration sensation should be assessed to have a correct examination of CRPS.<ref>FRONTERA, W, e.a., Essentials of Physical Medicine and Rehabilitation - Musculoskeletal disorders, pain and rehabilitation. Saunders Elsevier, 2002. (level of evidence 5)</ref> Most assessments are linked with each other. This means that when for example vibration sensation is very positive, light touch should be positive too.<ref>FRONTERA, W, e.a., Essentials of Physical Medicine and Rehabilitation - Musculoskeletal disorders, pain and rehabilitation. Saunders Elsevier, 2002. (level of evidence 5)</ref><br> <br>To help distinguish the findings of a sensory dysfunction, you have to compare the affected area with an unaffected area. The findings should be clear and reliable.<ref>FRONTERA, W, e.a., Essentials of Physical Medicine and Rehabilitation - Musculoskeletal disorders, pain and rehabilitation. Saunders Elsevier, 2002. (level of evidence 5)</ref><ref>SANDEEP, J., Complex Regional Pain Syndrome. Indian Journal of Plastic Surgery, 2011. (level of evidence 2A )</ref><br>  
Differential diagnosis includes the direct effects of the following conditions: <ref name="turner" /><ref>Thomson McBride AR, Barnett AJ, Livingstone JA, Atkins RM. [https://pubmed.ncbi.nlm.nih.gov/18716503/ Complex regional pain syndrome (type 1): a comparison of 2 diagnostic criteria methods.] Clin J Pain. 2008 Sep;24(7):637-40. </ref>  


<br>
*Bony or soft tissue injury
*Peripheral [https://physio-pedia.com/Neuropathies# neuropathy], nerve lesions
*[[Arthritis]]
*Infection
*[http://www.physio-pedia.com/Compartment_Syndrome Compartment syndrome]
*Arterial insufficiency
*[[Raynaud's Phenomenon|Raynaud’s Disease]]
*Lymphatic or venous obstruction (eg. DVT)
*[http://www.physio-pedia.com/Thoracic_Outlet_Syndrome Thoracic Outlet Syndrome (TOS)]
*Gardner-Diamond Syndrome
*Erythromelalgia
*Self-harm or malingering
*[[Cellulitis]]
*Undiagnosed fracture
== Diagnostic Procedures  ==


== Medical Management <br>  ==
CRPS diagnosis is mainly based on patient history, clinical examination, and supportive investigations.


There are 4 diagnostic tools for CRPS in adult populations. These include the Veldman criteria, IASP criteria, Budapest Criteria, and Budapest Research Criteria.<ref name=":1" /> 


=== The Budapest Criteria ===
The Budapest criteria (also known as the IASP criteria and explicitly endorsed by the IASP) has been developed for the diagnosis of CRPS, but improvements still need to be made. <ref name=":12">Harden NR, Bruehl S, Perez RSGM, Birklein F, Marinus J, Maihofner C, Lubenow T, Buvanendran A, Mackey S, Graciosa J, Mogilevski M, Ramsden C, Chont M, Vatine JJ. [https://pubmed.ncbi.nlm.nih.gov/20493633/ Validation of proposed diagnostic criteria (the "Budapest Criteria") for Complex Regional Pain Syndrome.] Pain. 2010 Aug;150(2):268-74. </ref><ref name=":15">Choi E, Lee PB, Nahm FS. [https://pubmed.ncbi.nlm.nih.gov/23331254/ Interexaminer reliability of infrared thermography for the diagnosis of complex regional pain syndrome.] Skin Res Technol. 2013 May;19(2):189-93.  </ref><ref name=":13">Harden NR. [https://pubmed.ncbi.nlm.nih.gov/22424876/ The diagnosis of CRPS: are we there yet?] Pain. 2012 Jun;153(6):1142-1143.  </ref> Clinical diagnostic criteria for  CRPS are: <ref name=":33" />
# Continuing pain, which is disproportionate to any inciting event
# Must '''report''' at least one '''symptom''' in three of the four following categories:
#* ''Sensory:'' hyperalgesia and/or allodynia
#* ''Vasomotor''''':''' temperature asymmetry and/or skin colour changes and/or skin colour asymmetry
#* ''Sudomotor/oedema:'' oedema and /or sweating changes and/or sweating asymmetry
#* ''Motor/trophic''''':''' decreased range of motion and/or motor dysfunction (weakness, tremor, dystonia) and/or trophic changes (hair, nail, skin)
# Must display at least one '''sign''' at the time of '''evaluation i'''n two or more of the following categories
#* ''Sensory:'' hyperalgesia (to pinprick) and/or allodynia (to light touch/pressure/joint movement)
#* ''Vasomotor''''':''' evidence of temperature asymmetry and/or skin colour changes and/or skin colour asymmetry
#* ''Sudomotor/oedema:'' evidence of oedema and /or sweating changes and/or sweating asymmetry
#* ''Motor/trophic''''':''' evidence of decreased range of motion and/or motor dysfunction (weakness, tremor, dystonia) and/or trophic changes (hair, nail, skin)
# There is no other diagnosis that better explains the signs and symptoms
The Budapest Criteria have excellent diagnostic sensitivity of 99%  and a moderate specificity of 68%. <ref name=":1">Mesaroli G, Hundert A, Birnie KA, Campbell F, Stinson J. [https://pubmed.ncbi.nlm.nih.gov/33230004/ Screening and diagnostic tools for complex regional pain syndrome: a systematic review.] Pain. 2021 May;162(5):1295-1304.</ref> See the video below for more detail on the Budapest Criteria.
{{#ev:youtube|FjZH7Fl1wLs}}


Treatment of complex regional pain syndrome should be immediate, and most importantly directed toward restoration of full function of the extremity. There are several options to treat CRPS.
<ref>Bia Education. Diagnostic criteria for CRPS. Available from: https://www.youtube.com/watch?v=FjZH7Fl1wLs [accessed 6/7/2023]</ref>
<ref>WASNER, G., et al., Complex regional pain syndrome - diagnostic, mechanisms, CNS involvement and therapy. International Spinal Cord Society, 2003. (level of evidence 2A)</ref>
=== Other Tests  ===


* '''Infrared Thermography:''' Infrared thermography (IRT) is an effective mechanism to find significant asymmetry in temperature between both limbs by determining if the affected side of the body shows vasomotor differences in comparison to the other side. It is reported having a sensitivity of 93% and a specificity of 89%. <ref name=":16">Albazaz R, Wong YT, Homer-Vanniasinkam S. [https://pubmed.ncbi.nlm.nih.gov/18346583/ Complex regional pain syndrome: a review.] Ann Vasc Surg. 2008 Mar;22(2):297-306. </ref> This test is hard to obtain so it is not often used for diagnosing of CRPS. <ref name=":15" /> <ref name=":14">Perez RS, Collins S, Marinus J, Zuurmond WW, de Lange JJ. [https://pubmed.ncbi.nlm.nih.gov/17400490/ Diagnostic criteria for CRPS I: differences between patient profiles using three different diagnostic sets.] Eur J Pain. 2007 Nov;11(8):895-902. </ref><ref name=":16" />
* '''Sweat Testing:''' Determining if the patient sweats abnormally. Q-sweat is an adequate instrument to measure sweat production. The sweat samples should be taken from both sides of the body at the same time. <ref name=":3" /><ref name=":16" />
* '''Radiographic testing:''' Irregularities in the bone structure and osteopenia of the affected side of the body can become visible with the use of [http://www.physio-pedia.com/X-Rays X-rays]. <ref name=":3" /> <ref name=":16" />
* '''Three phase bone scan:''' A triple phase bone scan is the best method to rule out Type I CPRS. <ref>Cappello ZJ, Kasdan ML, Louis DS. [https://pubmed.ncbi.nlm.nih.gov/22177715/ Meta-analysis of imaging techniques for the diagnosis of complex regional pain syndrome type I.] J Hand Surg Am. 2012 Feb;37(2):288-96.</ref> With the use of technetium Tc 99m-labeled bisophosphonates, an increase in bone metabolism can be shown. Higher uptake of the substance means increased bone metabolism and the body part could be affected. <ref name=":16" />  The triple-phase bone scan has the best sensitivity, NPV, and PPV compared to MRI and plain film radiographs.
* '''Bone densitometry:''' An affected limb often shows less bone mineral density and a change in the content of the bone mineral. During treatment of the CPRS the state of the bone mineral will improve. So this test can also be used to determine if the patient’s treatment is effective. <ref name=":16" />
* '''Magnetic Resonance Imaging (MRI):''' [https://www.physio-pedia.com/MRI_Scans MRI scans] are useful to detect periarticular marrow oedema, soft tissue swelling and joint effusions. And in a later stage, atrophy and fibrosis of periarticular structures can be detected. But these symptoms are not exclusively signs of CRPS. <ref name=":3" /><ref name=":16" />


Bone demineralization is not unusual in CRPS patients, so treatment with calcitonin and biphosphonates is suitable. Calcitonin has received considerable interest in the management of CRPS because of its analgesic properties through release of ß-endorphin as well as its inhibition of bone resorption.<ref>TRAN, Q., e.a., Treatment of complex regional pain syndrome: a review of the evidence. Canadian Anesthesiologists’ Society, 2010. (level of evidence 1A)</ref> Biphosphonates are potent inhibitors of bone resorption; <br>- Alendronate: less pain and swelling, more range of motion.<ref>TRAN, Q., e.a., Treatment of complex regional pain syndrome: a review of the evidence. Canadian Anesthesiologists’ Society, 2010. (level of evidence 1A)</ref><ref>WASNER, G., et al., Complex regional pain syndrome - diagnostic, mechanisms, CNS involvement and therapy. International Spinal Cord Society, 2003. (level of evidence 2A)</ref><ref>ADAMI, S., et al., Bisphosphonate therapy of reflex sympathetic dystrophy syndrome. Ann Rheum Dis,1997. (level of evidence 2B)</ref><br>- Clodronate: less pain, improved global assessment (evaluated by investigator), and higher perceived efficacy (evaluated by patients).<ref>TRAN, Q., e.a., Treatment of complex regional pain syndrome: a review of the evidence. Canadian Anesthesiologists’ Society, 2010. (level of evidence 1A)</ref><ref>WASNER, G., et al., Complex regional pain syndrome - diagnostic, mechanisms, CNS involvement and therapy. International Spinal Cord Society, 2003. (level of evidence 2A)</ref><ref>VARENNA, M., et al., Intravenous clodronate in the treatment of reflex sympathetic dystrophy syndrome. A randomized, double blind, placebo controlled study. Journal of Rheumatology, 2000. (level of evidence 2B)</ref><br>- Palmidronate: less pain, higher overall improvement (patient’s assessment), and higher functional assessment scores.<ref>TRAN, Q., e.a., Treatment of complex regional pain syndrome: a review of the evidence. Canadian Anesthesiologists’ Society, 2010. (level of evidence 1A)</ref><ref>ROBINSON, J.N., et al., Efficacy of pamidronate in complex regional pain syndrome type I. Pain Medicine, 2004. (level of evidence 2B)</ref><br>Generally biphosphonates have been shown to decrease pain and swelling as well as to increase range of motion for patients with CRPS<ref>TRAN, Q., e.a., Treatment of complex regional pain syndrome: a review of the evidence. Canadian Anesthesiologists’ Society, 2010. (level of evidence 1A)</ref>
== Outcome Measures  ==


An excessive inflammatory reaction can lead to the overproduction of free radicals, resulting in the destruction of healthy tissue and possibly leading to CRPS. Thus, free radical scavengers have been proposed to curtail the disease process. To date, three free radical scavengers, like dimethyl sulfoxide (DMSO), have been investigated for the treatment of CRPS.<ref>TRAN, Q., e.a., Treatment of complex regional pain syndrome: a review of the evidence. Canadian Anesthesiologists’ Society, 2010. (level of evidence 1A)</ref><br>A scorelist (based on pain, daily activities, edema, color, and ROM) showed greater improvement by dimethyl sulfoxide treatment. DMSO seems to provide a mild improvement in range of motion and vasomotor instability in patients with CRPS.<ref>TRAN, Q., e.a., Treatment of complex regional pain syndrome: a review of the evidence. Canadian Anesthesiologists’ Society, 2010. (level of evidence 1A)</ref>
The CRPS consortium has established a list of core outcome measures to be used for patients with CRPS (referred to as COMPACT).<ref>Grieve S, Perez RS, Birklein F, Brunner F, Bruehl S, Harden N, Packham T, Gobeil F, Haigh R, Holly J, Terkelsen A. Recommendations for a first Core Outcome Measurement set for complex regional PAin syndrome Clinical sTudies (COMPACT). Pain. 2017 Jun;158(6):1083.</ref>  


Biopsy studies showing tissue inflammation in CRPS caused many researchers to use steroids.These steroids showed great improvement in pain and edema. They showed a better post treatment score.<ref>WASNER, G., et al., Complex regional pain syndrome - diagnostic, mechanisms, CNS involvement and therapy. International Spinal Cord Society, 2003. (level of evidence 2A)</ref><ref>CHRISTENSEN, K., et al., The reflex dystrophy syndrome response to treatment with systemic corticosteroids. Acta Chir Scand 1982. (level of evidence 2B)</ref><ref>BRAUS, D.F., et al., The shoulder-hand syndrome after stroke: a prospective clinical trial. Annals of Neurology, 1994. (level of evidence 1B)</ref>
'''Patient reported Outcome Measures:'''


Intravenous immunoglobulin can reduce pain in refractory CRPS.The average pain intensity was 1.55 units lower after IVIG treatment.<ref>GOEBEL, A. et al., Intravenous Immunoglobulin Treatment of the Complex Regional Pain Syndrome: A Randomized Trial, Annals of internal medicine, 2010. (level of evidence 1B)</ref>
* [https://www.unmc.edu/centric/_documents/PROMIS-29.pdf PROMIS-29:] Assesses 7 domains (physical function, pain interference, fatigue, depression, anxiety, sleep, social participation)
* [[Numeric Pain Rating Scale|NPRS]]: Numeric pain rating scale
* [[Short-form McGill Pain Questionnaire]] (SF-MPQ-2): Six neuropathic items capture pain quality
* [[Pain Catastrophizing Scale|Pain Catastrophising Scale]]
* [[EQ-5D|EQ-5D-5L:]] Measurement of health state
* [[Pain Self-Efficacy Questionnaire (PSEQ)|Pain Self-efficacy Questionnaire]]
* CRPS symptom questions: Derived from the Budapest Criteria


Hyperbaric oxygen therapy is an effective and well tolerated method for decreasing pain, allodynia, oedema and increasing the range of motion in CRPS. Also, the skin colour returns to normal.<ref>TRAN, Q., e.a., Treatment of complex regional pain syndrome: a review of the evidence. Canadian Anesthesiologists’ Society, 2010. (level of evidence 1A)</ref><ref>KIRALP, M.Z. et al., Effectiveness of Hyperbaric Oxygen Therapy in the Treatment of Complex Regional Pain Syndrome, The Journal of International Medical Research, 2004. (level of evidence 1B)</ref>
'''Clinical reported Outcome Measures:'''


In the majority of patients with chronic reflex sympathetic dystrophy, electrical stimulation of the spinal cord can reduce pain intensity and improve health-related quality of life.<ref>KEMLER M. et al., Spinal Cord Stimulation in Patients with Chronic Reflex Sympathetic Dystrophy. The New England Journal of Medicine, 2000. (level of evidence 2B)</ref><ref>FOROUZANFAR T. et al., Spinal cord stimulation in complex regional pain syndrome: cervical and lumbar devices are comparably effective. British Journal of Anaesthesia, 2004. (level of evidence 2B)</ref><br>
* ''CRPS Severity Score (CSS):'' Includes 8 signs and 8 symptoms that reflect the sensory, vasomotor, sudomotor/edema and motor/trophic disorders of CPRS, coded based on the history and physical examination. Extent of changes in CSS scores over time are significantly associated with changes in pain intensity, fatigue, and functional impairments. Thus, the CSS appears to be valid and sensitive to change. A change of 5 or more CSS scale points reflects a clinically-significant change. <ref name=":33" />


<br>
'''Other Outcome Measures''' (not part of COMPACT)''':'''


== Physical Therapy Management <br==
* Various region specific functional measures can be used for either upper limb or lower limb CRPS, eg. [[Grip Strength|Grip strength]] <ref>Hotta J, Harno H, Nummenmaa L, Kalso E, Hari R, Forss N. [https://onlinelibrary.wiley.com/doi/abs/10.1002/ejp.669 Patients with complex regional pain syndrome overestimate applied force in observed hand actions.] Eur J Pain. 2015;19(9):1372-81. </ref>


== Examination  ==


The diagnosis is based on the clinical presentation described above. Procedures start with taking a detailed medical history, taking into account any initiating trauma and any history of sensory, autonomic, and motor disturbances, as well as how the symptoms developed, the time frame, distribution and characteristics of pain. Assessment for any swelling, sweating, trophic and/or temperature increases, and motor abnormality in the disturbed area is important. Skin temperature differences may be helpful for diagnosis of CRPS. The original IASP criteria required only a history and subjective symptoms for a diagnosis of CRPS, but recent consensus guidelines have argued for the inclusion of objective findings. <ref name=":23">PENTLAND, B. [https://www.taylorfrancis.com/chapters/edit/10.4324/9780203989326-54/parkinsonism-dystonia-pentland Parkinsonism and dystonia.] By: Greenwood R, McMillan T, Barnes M, Ward C. (eds) Handbook of Neurological Rehabilitation. 1st ed.  London: Psychology Press, 2002. </ref>


It is difficult to manage CRPS because there is lack of understanding of the pathophysiologic abnormalities and lack of specific diagnostic criteria. In literature there is very low quality evidence to treat CRPS.
The clinical presentation of CRPS, and the underlying mechanisms, can differ between patients and even within a patient over time - it is therefore important assess underlying pain mechanisms in order to design targeted treatment for each individual.<ref name=":33">Harden RN, McCabe CS, Goebel A, Massey M, Suvar T, Grieve S, Bruehl S. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9186375/ Complex regional pain syndrome: practical diagnostic and treatment guidelines.] Pain Medicine. 2022 May 1;23(Supplement_1):S1-53.</ref>
<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref>
<br>The main goals of treating the patient are reduction of pain, preservation of limb function and return to work. Don’t forget to check the comorbidities such as depression, sleep disturbance and anxiety. Those have to be treated concurrently.<br>The basic rule is treating the patient in a multidisciplinary approach. This multidisciplinary team should include neurologists, anesthesiologists, orthopedics, physiotherapists and psychologists.


# '''Autonomic Dysfunction:''' The majority of patients with CRPS have bilateral differences in limb temperature and the skin temperature depends of the chronicity of the disease. In the acute stages, temperature increases are often concomitant with a white or reddish colouration of the skin and swelling. where the syndrome is chronic, the temperature will decrease and is associated with a bluish tint to the skin and atrophy. <ref name=":25">Frontera W, Silver J. [https://shop.elsevier.com/books/essentials-of-physical-medicine-and-rehabilitation/frontera/978-0-323-54947-9 Essentials of Physical Medicine and Rehabilitation - Musculoskeletal disorders, Pain and Rehabilitation.] Saunders Elsevier, 2002.</ref>
# '''Motor Dysfunction:''' Studies have shown that approximately 70% of the patients with CRPS show muscle weakness in the affected limb, exaggerated tendon reflexes or tremor, irregular myoclonic jerks, and dystonic muscle contractions. Muscle dysfunction often coincides with a loss of range of motion in the distal joints. <ref name=":24">Sebastin SJ. [https://pubmed.ncbi.nlm.nih.gov/22022040/ Complex regional pain syndrome.] Indian J Plast Surg. 2011 May;44(2):298-307. </ref>
# '''Sensory Dysfunction:''' The distal ends of the extremities require attention when examining a patient with CRPS. However, common findings of regional neuropathic and motor dysfunction have shown us that it is important to broaden the examination both proximally and contralaterally. <ref name=":25" />Light touch, pinprick, temperature and vibration sensation should be assessed for a complete picture of the CRPS. <ref name=":25" /> Most assessments are interlinked,  for example, when vibration sensation is highly positive, light touch should also be positive. <ref name=":25" />To help distinguish the findings of a sensory dysfunction, bilateral comparisons are made. <ref name=":24" /><ref name=":25" />Also see [[Quantitative Sensory Testing (QST)|Quantitative Sensory Testing.]]


== Multidisciplinary Management  ==


The treatment should be based on basic principles of pain management (pain and symptom relief, supportive care, rehabilitation). Due to the lack of evidence in treatment of CRPS we have to rely on treatments of other neuropathic pain syndromes.<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref><ref>BARON, R., Complex regional pain syndromes. Curr Pain Headache Rep., 2001. (level of evidence 2A)</ref>
CRPS can be very difficult to treat successfully, as it involves both central and peripheral pathophysiology, as well as frequent psychosocial components.<ref name=":33" />  This complexity of CRPS calls for an interdisciplinary approach, where the entire management team collaborates and focuses on all the relevant biopsychosocial elements. In many settings this is not feasible - in such cases a multidisciplinary approach is still very important to address the multifactorial nature of CRPS.<ref name=":33" /> Treatment of complex regional pain syndrome should be immediate, and most importantly directed toward functional restoration. Functional restoration emphasises physical activity, desensitisation and normalisation of sympathetic tone, and involves steady progression. <ref name=":33" />  


=== Treatment Overview ===
Despite multiple interventions being described and commonly used, the optimal management of CRPS is still under debate. The latest published evidence from Cochrane and non‐Cochrane systematic reviews of the efficacy, effectiveness, and safety interventions did not identify high‐certainty evidence for the effectiveness of any therapy for CRPS. <ref name=":18">Ferraro MC, Cashin AG, Wand BM, Smart KM, Berryman C, Marston L, Moseley GL, McAuley JH, O'Connell NE. [https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD009416.pub3/full Interventions for treating pain and disability in adults with complex regional pain syndrome‐ an overview of systematic reviews.] Cochrane Database of Systematic Reviews, 2023; 6: CD009416. </ref> This paper was the first update of the original Cochrane review in 2013. <ref name=":18" />


Nevertheless, the following table summarises treatment recommendations for CRPS. These strategies are based on the Malibu CRPS algorithm and most recent treatment guidelines.<ref name=":33" />
{| class="wikitable"
|+'''CRPS treatment overview'''
!
!'''Description & Modalities'''
!'''Team members'''
|-
!'''''Functional Restoration'''''
!
!
|-
|'''Phase 1:''' Activation of pre-sensorimotor cortices
|[[Graded Motor Imagery|Graded motor imagery]]
Visual tactile discrimination
|PT/OT
|-
|'''Phase 2:''' Gentle active ROM
|Progressive AROM
Isometric strengthening
|PT
|-
|'''Phase 3:''' Weight bearing
|UL: carrying items
LL: partial weight bearing
|PT/OT
|-
|'''''Desensitisation'''''
|Progressive stimulation with textures (soft to more rough)
Contrast baths with progressive broadening of the temp difference
|OT/PT
|-
|'''''Pain Management'''''
|Sympathetic blocks and/or medication to allow engagement with functional restoration
Functional restoration addresses pain by normalising afferent inputs and central processing
|MD
PT
|-
|'''''Edema Management'''''
|Pressure garments
Aquatic therapy
General aerobic activity
|PT/OT
|-
|'''''Psychological approaches'''''
|CBT and exposure-based therapy if patient presents with kinesiophobia
Psychotherapy if depression/anxiety is present
|Psych/PT
|-
|'''''Secondary impairments'''''
|Local muscle spasm, reactive bracing and disuse atrophy secondary to pain needs to be addressed
|PT
|}


'''Acute phase'''<br>Immobilization and contralateral therapy should be the treatment in the acute phase. Intensive active therapy in the acute phase can lead to deterioration.<ref>BARON, R., Complex regional pain syndromes. Curr Pain Headache Rep., 2001. (level of evidence 2A)</ref>
==== Medical Management ====
Medical management is aimed at achieving sufficient pain relief, in order to allow for rehabilitation interventions to commence and progress. Most medications used for CRPS lack high quality evidence, and most treatment regimes are extrapolated from evidence for related [[Neuropathic Pain|neuropathic]] conditions. CRPS does however differ from other neuropathic conditions in that additional circulatory, bone and inflammatory pathways are present<ref name=":33" />. Patients also present with a varying dominant mechanisms (including central sensitisation, motor abnormalities and sympathetic abnormalities), and it is therefore important to base medication prescription on reasoning regarding evident underlying mechanisms. Below is a summary of the possible medical interventions for patients with CRPS: 
{| class="wikitable"
|+Medical interventions for CRPS<ref name=":33" />
!
!'''Description'''
!'''Evidence/ considerations'''
|-
!'''Pharmacotherapy'''
!
!
|-
|''Anti-inflammatory drugs''
|[[NSAIDs]] (esp Ketoprofen), COX-2 inhibitors, corticosteroids
|Useful to address the inflammatory component of CRPS, but often not effective as [[Neurogenic Inflammation|neurogenic inflammation]] mostly dominant. Risks regarding long-term use needs to be considered
|-
|''Biphosponates''
|Have immune-modulatory properties and modulate bone metabolism
|May help in acute stages or in selected subtypes of CRPS (where osteopenia is evident), but the evidence is lacking
|-
|''Cation-Channel blockers''
|Anticonvulsants (gabapentin/pregabalin)
|Proven efficacy for other neuropathic pain conditions; evidence for CRPS is lacking
|-
|''Tricyclic drugs''
|Anti-depressants that augment descending inhibition
|Effective for other neuropathic conditions; worth considering in patients with associated insomnia, depression and/or anxiety
|-
|''Opioids''
|Tramadol
Methadone
|Tolerance and long-term toxicity are important concerns, and can worsen allodynia and hyperalgesia; daily use is not recommended in CRPS - only for excruciating pain
|-
|''NMDA Antagonists''
|Ketamine
|High risk of toxicity; IV ketamine may have positive effects on central sensitisation
|-
|''Alpha2-adrenergic Agonists/ Ca-channel blockers''
|Clonidine
Nifedipine
|Evidence is contradictory. Adverse effects can occur
|-
|''Calcitonin''
|Hormone produced by the thyroid
|A meta-analysis demonstrated benefits of intranasal administration, but subsequent studies had conflicting results
|-
|''Immune modulators''
|Steroids
Immunoglobulins (IVIG)
|Evidence suggests that early initiation (after trauma), followed by tapering, may be effective
Steroid injections are ineffective
IVIG has limited evidence
|-
|'''Other'''
|
|
|-
|''Topical treatment''
|Lidocaine
Capsaicin
|Capsaicin can be intolerably painful in the presence of hyperalgesia
|-
|''Supplements''
|Vitamin C
|Daily Vit C following limb fracture or surgery may prevent CRPS
|-
|''Sympathetic blocks''
|Local anaesthetic block applied at the transverse process of C6 or L2/3
|High quality evidence is lacking, but may be useful for a subset of patients with prominent vasomotor dysfunction, to provide pain relief and a window of opportunity for rehabilitation techniques<ref name=":33" /><ref name=":16" />
|-
|''Spinal cord stimulations''
|Aims to inhibit the nociceptive pathways at the level of the dorsal column
|Reserved for use when patients are not responding to other interventions. Safe and proven long-term effective for chronic CRPS<ref name=":33" />
|-
|''Dorsal root ganglion stimulation''<ref name=":0" />
|Aims to modulate nociceptive pathways at the dorsal root
|Evidence shows reduced pain, improved quality of life and function if conservative therapy has failed<ref name=":33" />
|}
It is likely that medication prescription will need to be adapted over time as CRPS progresses or patients develop tolerance. The following table presents a consensus-based pharmacotherapy guide based on clinical findings in CRPS: <ref name=":33" />
{| class="wikitable"
!'''Reason for inability to start/progress with rehab'''
!'''Pharmacotherapy reccommendations'''
|-
|''Mild to moderate pain''
|Simple analgesics and/or blocks
|-
|''Excruciating pain''
|Opioids and/or blocks
|-
|''Inflammation and oedema''
|Steroids, NSAIDs, immune modulators
|-
|''Depression, insomnia''
|Anti-depressants
|-
|''Severe allodynia/hyperalgesia''
|Anticonvulsants and/or NMDA antagonists
|-
|''Osteopenia and trophic changes''
|Calcitonin or biphosphonates
|-
|''Profound vasomotor disturbance''
|Calcium channel blockers and/or blocks
|}
=== Physiotherapy Management ===
Various consensus groups have emphasised that physiotherapy is of utmost importance in restoring function in patients with CRPS.<ref name=":3" /><ref name=":33" />  Studies have shown that exercise-based physiotherapy is effective in managing pain and reducing impairment. <ref name=":33" /><ref name=":4">Lee BH, Scharff L, Sethna NF, McCarthy CF, Scott-Sutherland J, Shea AM, Sullivan P, Meier P, Zurakowski D, Masek BJ, Berde CB. [https://pubmed.ncbi.nlm.nih.gov/12091866/ Physical therapy and cognitive-behavioral treatment for complex regional pain syndromes.] J Pediatr. 2002 Jul;141(1):135-40.  </ref>


Physiotherapy aims to restore function, using the following intervention strategies:
*[[Graded Motor Imagery|'''Graded Motor Imagery''']] (GMI): Aims to address altered central processing by restoring the mismatch between afferent input and central representation. A meta-analysis demonstrated very good evidence for the efficacy of GMI in combination with medical management in patients with CRPS-1, with many studies indicating improvements in pain and function.<ref name=":2" /><ref name=":26" /><ref>Daly AE, Bialocerkowski AE. Does evidence support physiotherapy management of adult Complex Regional Pain Syndrome Type One? A systematic review. European Journal of Pain. 2009 Apr 1;13(4):339-53.</ref><ref name=":31">Moseley GL. [https://pubmed.ncbi.nlm.nih.gov/15109523/ Graded motor imagery is effective for long-standing complex regional pain syndrome: a randomised controlled trial.] Pain. 2004 Mar;108(1-2):192-8.  </ref>[[File:Mirror therapy.jpg|thumb]]
*'''[[Mirror Therapy|Mirror visual feedback (MVF)]]:''' Proven to be effective in patients with CRPS-1 and for stroke patients with CRPS.<ref name=":33" /> <ref name=":17">McCabe CS, Haigh RC, Blake DR. [https://pubmed.ncbi.nlm.nih.gov/18474189/ Mirror visual feedback for the treatment of complex regional pain syndrome (type 1).] Curr Pain Headache Rep. 2008 Apr;12(2):103-7.</ref><ref name=":26" />It is critical that the patient 'believes' the illusion.
*'''Tactile sensory discrimination training'''  <ref name=":26" /><ref name=":32">Bowering KJ, O'Connell NE, Tabor A, Catley MJ, Leake HB, Moseley GL, Stanton TR. [https://pubmed.ncbi.nlm.nih.gov/23158879/ The effects of graded motor imagery and its components on chronic pain: a systematic review and meta-analysis.] J Pain. 2013 Jan;14(1):3-13.  </ref>
*'''Progressive strengthening:''' Starting with isometrics, and then gently progressing isotonic and resisted movements.<ref name=":26" />
*'''Education and pacing:''' Patients need to be told that both too much and too little movement can increase pain, and physiotherapists need to help patients to find a "happy medium", while guiding them towards more function.<ref name=":33" />Incorporating [[Pain Neuroscience Education (PNE)|pain neuroscience education (PNE)]] elements can help reduce kinesiophobia by explaining that pain does not signal tissue damage.<ref name=":33" />
*'''[[Flexibility]]/ROM exercises:''' Active ROM and functional movements, while maintaining good movement patterns. Bilateral movements and conscious attention to the limb should be encouraged. <ref name="goebel" />Graded exposure can help to reduce kinesiophobia.
*[[Aquatherapy|'''Aquatic therapy''']]: Allows activities to be performed with decreased weight bearing on the lower extremities, which can be a tolerable way of introducing weight bearing/resistance exercises. Hydrostatic pressure also provides gentle compression around the joints which can reduce oedema.<ref name=":33" />
*[[Desensitization|'''Desensitisation:''']] Consist of giving stimuli of different fabrics, different pressures (light or deep), vibration, tapping, heat or cold. See OT section <ref name="goebel" /><ref name=":33" />
*'''Gradual weight bearing:''' Exposure the affected extremity to gradually increasing weight bearing activities. Gait training should be included for lower limb CRPS. <ref name="goebel" /><ref name=":33" /><ref name=":2" /><ref name=":30">Smith TO. [https://pubmed.ncbi.nlm.nih.gov/17042007/ How effective is physiotherapy in the treatment of complex regional pain syndrome type I? A review of the literature.] Musculoskeletal Care. 2005;3(4):181-200. </ref>
*[[Transcutaneous Electrical Nerve Stimulation (TENS)|'''TENS''']]: Evidence is lacking, but may have some benefit<ref name=":33" />


* '''[[Relaxation Techniques|Relaxation]] exercises:''' The efficacy of relaxation-focused interventions (such as [[Diaphragmatic Breathing Exercises|diaphragmatic breathing]]) may be impaired due to the physiological alterations associated with CRPS. <ref name=":30" /><ref name=":33" />
Physiotherapists should '''avoid''' aggressive exercises, prolonged application of ice and prolonged rest/inactivity - these can exacerbate symptoms.<ref name=":33" /> '''Massage''' lacks evidence, but may be useful in oedema management if applied carefully.<ref name=":33" /><ref name=":2" /><ref name=":26" />


'''Chronic phase'''<br>1. Passive physical therapy including manipulation, manual therapy<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref>, massage<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref><ref>TRAN, Q., e.a., Treatment of complex regional pain syndrome: a review of the evidence. Canadian Anesthesiologists’ Society, 2010. (level of evidence 1A)</ref> and mobilizations. Lymphatic drainage can be used to facilitate regression of [http://www.physio-pedia.com/Lymphatic_Obstruction_%28Lymphedema%29 edema].<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref> You can also threat tender points by the following rules: more severe tender points as identified by tenderness to palpation are treated before less severe tender points; more proximal or more medial tender points are addressed before more distally and laterally located points; the area of greatest accumulation of tender points is treated first; when tender points are located in a row, the one in the middle of the row is treated first.<ref>COLLIN, C., Physical Therapy Management of Complex Regional Pain Syndrome I in a 14-Year-Old Patient Using Strain Counterstrain: A Case Report. J Man Manip Ther., 2007. level of evidence 4)</ref> (level of evidence 4)
Since the mechanisms underlying CRPS are often widespread, it may be beneficial to involve unaffected extremities during exercises, especially when moving the affected extremity is too painful.<ref name="Hooshmand" />  


<br>2. Therapeutic exercise including isometric strengthening therapy followed by active isotonic training in combination with sensory [http://www.physio-pedia.com/Desensitization desensitization] programs.<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref> 70<ref>BARON, R., Complex regional pain syndromes. Curr Pain Headache Rep., 2001. (level of evidence 2A)</ref> (level of evidence 3A) The strengthening training includes exercises for all four extremities and trunk. The exercises can be done with Theraband.<ref>STANTON-HICKS, M., et al., Complex Regional Pain Syndromes: Guidelines for Therapy. The Clinical Journal of Pain, 1998. (level of evidence 5)</ref> Desensitization programs contains giving stimuli of different fabrics, different pressure (light or deep), vibration, tapping, heat or cold. The exercises can be stress-loading (f.e. scrubbing, walking, carrying weights), endurance training, written instructions and functional training.<ref>STANTON-HICKS, M., et al., Complex Regional Pain Syndromes: Guidelines for Therapy. The Clinical Journal of Pain, 1998. (level of evidence 5)</ref> When CRPS occurs in the lower extremities, in that case including gait training in the therapy is recommended.<ref>COLLIN, C., Physical Therapy Management of Complex Regional Pain Syndrome I in a 14-Year-Old Patient Using Strain Counterstrain: A Case Report. J Man Manip Ther., 2007. level of evidence 4)</ref> (level of evidence 4). It is also useful to give the patient an home exercise program.<ref>STANTON-HICKS, M., et al., Complex Regional Pain Syndromes: Guidelines for Therapy. The Clinical Journal of Pain, 1998. (level of evidence 5)</ref><br>
=== Occupational Therapy Management ===
Occupational therapists (OTs) are pivotal in the functional restoration process as experts in biopsychosocial principles and functional assessment. The role of the OT involves initial functional evaluation (including ROM, coordination, dexterity, pain, sensation and use of the extremity during ADLs), followed by various intervention strategies, including:


* '''[[Graded Motor Imagery|GMI]] and [[Mirror Therapy|Mirror visual feedback]]'''
* '''[[Desensitization|Desensitisation:]]''' Involves graded exposure to textures (from soft to more textured). Aids in normalisation of cortical organisation in CRPS patients by restoring the sensory cortex<ref name=":33" /><ref name=":29">Stanton-Hicks M, Baron R, Boas R, Gordh T, Harden N, Hendler N, Koltzenburg M, Raj P, Wilder R. [https://pubmed.ncbi.nlm.nih.gov/9647459/ Complex Regional Pain Syndromes: guidelines for therapy.] Clin J Pain. 1998 Jun;14(2):155-66.  </ref>
* '''Oedema Management''': Using specialised garments and manual oedema mobilisation. <ref name=":33" />
* '''[[Splinting]]:''' May be indicated in severe cases to promote improved circulation to the area and to facilitate more normal positioning. Symptoms can be exacerbated by splinting and should therefore be closely monitored.<ref name=":33" />
* '''Stress loading:''' This involves active movement and compression of the affected joints, and although it may at first increase symptoms, this is usually followed by reduced pain and swelling. It consists of: <ref name=":33" />
** ''Scrubbing -'' moving the affected extremity back/forth while weight bearing through the extremity, using a scrub brush in the quadruped position/sitting
** ''Carrying -'' small objects carried in the hand throughout the day, progressing to heavier items (UL); weight shifting, walking, standing with one foot on step, ball tossing towards the affected limb (LL)
* '''Functional retraining''': Graded increase in functional use of  the extremity as pain allows to increase independence in ADLs. Can be facilitated with [[Neurology Treatment Techniques|PNF]] pattern strengthening
* '''Vocational rehabilitation and reintegration:''' Job site analysis, job specific conditioning/ work hardening, work capacity evaluation and transferable skills analysis.<ref name=":33" /><ref name=":26" />
* '''Contrast baths:''' Mild contrast baths may be useful in the early stages of CRPS to improve circulation. In more advanced CRPS, vasomotor changes interfere with these effects and cold water emersion can exacerbate symptoms. It is therefore usually not recommended in patients with CRPS.<ref name=":33" />


=== Psychotherapy ===
In CRPS, psychological factors are important to target to ensure optimal outcomes. Solely treating psychological aspects is however not sufficient, as clear biological elements exist in CRPS - evidence suggests that psychological interventions are most effective when combined with physiotherapy.<ref name=":33" />


3. [http://www.physio-pedia.com/Mirror_Therapy Mirror therapy] or mirror visual feedback<ref>SMITH, T., How effective is physiotherapy in the treatment of complex regional pain syndrome type I? A review of the literature. Musculoskeletal care, 2005. (level of evidence 3A)</ref> (level of evidence 3A)<br>Mirror therapy contains placing both hands into a box with a mirror separating the two compartments and, while moving both hands, watching the reflection of the unaffected hand in the mirror<ref>TRAN, Q., e.a., Treatment of complex regional pain syndrome: a review of the evidence. Canadian Anesthesiologists’ Society, 2010. (level of evidence 1A)</ref><br>Evidence:<br>-reducing pain intensity and improve function in post-stroke CRPS<ref>MCGABE, C.S., et al., Mirror visual feedback for the treatment of complex regional pain syndrome (Type 1). Current Pain and Headache Reports, 2008. (level of evidence 2A)</ref> (level of evidence 2A)<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref><ref>BOWERING, K. J., The effects of graded motor imagery and its components on chronic pain: a systematic review and meta-analysis. The American Pain Society, 2013. (level of evidence 1A)</ref><br>-a significant improvement in pain with mirror therapy in a study where they compare a group with mirror therapy doing the same exercises as a group without mirror<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref> (level of evidence 2C)<br>-improve function (low quality evidence)<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref><br>-no conclusions could be drawn regarding the efficacy of mirror therapy (Rothgangel)<ref>ROTHGANGEL, A.S., et al., The clinical aspects of mirror therapy in rehabilitation: a systematic review of the literature. International Journal of Rehabilitation Research,  2011. (level of evidence 3A)</ref><br> <br>4. Graded motor imagery/learning<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref><ref>TRAN, Q., e.a., Treatment of complex regional pain syndrome: a review of the evidence. Canadian Anesthesiologists’ Society, 2010. (level of evidence 1A)</ref><ref>MOSELEY, G.L., Graded motor imagery is effective for long standing complex regional pain syndrome: a randomised controlled trial. Pain, 2004.  (level of evidence 1B)</ref><ref>SMITH, T., How effective is physiotherapy in the treatment of complex regional pain syndrome type I? A review of the literature. Musculoskeletal care, 2005. (level of evidence 3A)</ref> (level of evidence 1B) <br>Graded motor imagery consists of recognition of hand laterality (= pictures were presented of right and left hands and then you have to identify the correct size) and imagined hand movement (= pictures of a hand in different positions are presented and then the patient has to move his hand in that position).<ref>TRAN, Q., e.a., Treatment of complex regional pain syndrome: a review of the evidence. Canadian Anesthesiologists’ Society, 2010. (level of evidence 1A)</ref><br>Evidence:<br>-Further trials are required<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref><ref>TRAN, Q., e.a., Treatment of complex regional pain syndrome: a review of the evidence. Canadian Anesthesiologists’ Society, 2010. (level of evidence 1A)</ref> (level of evidence 1B)<br>-GMI plus medical management more effective than medical management plus physiotherapy<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref> (level of evidence 3A)<br>-GMI may reduce pain and improve function<ref>MOSELEY, G.L., Graded motor imagery is effective for long standing complex regional pain syndrome: a randomised controlled trial. Pain, 2004.  (level of evidence 1B)</ref> (level of evidence 1B)<br> <br>5. Relaxation<ref>BRUEHL, S., Psychological interventions. In: Harden RN editor(s). Complex regional pain syndrome: treatment guidelines. Reflex Sympathetic Dystrophy Syndrome Association, 2006 (level of evidence 1C)</ref><ref>SMITH, T., How effective is physiotherapy in the treatment of complex regional pain syndrome type I? A review of the literature. Musculoskeletal care, 2005. (level of evidence 3A)</ref> (level of evidence 1C)<br>[http://www.physio-pedia.com/Cognitive_Behavioural_Therapy Cognitive-behavioral therapy]<ref>LEE, B., et al., Physical therapy and cognitive-behavioral treatment for complex regional pain syndromes. Pain Treatment Service, 2002. (level of evidence 2B)</ref> (level of evidence 2B) contains relaxation training, deep breathing exercises, biofeedback. 4 Relaxation therapy falls under the responsibility of the psychologist.<br> <br>6. Neuromodulation or invasive stimulation techniques<br>Neuromodulation contains peripheral nerve stimulation with implanted electrodes, epidural spinal cord stimulation, deep brain stimulation and electrotherapy.<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref><br>[http://www.physio-pedia.com/Current_Concepts_in_Electrotherapy Electrotherapy] includes transcutaneous electric nerve stimulation [http://www.physio-pedia.com/Transcutaneous_Electrical_Nerve_Stimulation_%28TENS%29 TENS]<ref>OAKLANDER, A., et al., Evidence of focal small-fiber axonal degeneration in complex
There is currently no compelling evidence that psychiatric disorders contribute to the development of CRPS, but as a chronic pain condition, depression and distress can be common in these patients. <ref name=":33" />The aim of psychological interventions should be to address any factors that interfere with functional progression and to assist the psychological impact of a continued, severe pain experience<ref name=":33" />.
regional pain syndrome-I (reflex sympathetic dystrophy). Pain, 2006. (level of evidence 1B)</ref><ref>SMITH, T., How effective is physiotherapy in the treatment of complex regional pain syndrome type I? A review of the literature. Musculoskeletal care, 2005. (level of evidence 3A)</ref> (level of evidence 3A), Spinal cord stimulation SCS<ref>TRAN, Q., e.a., Treatment of complex regional pain syndrome: a review of the evidence. Canadian Anesthesiologists’ Society, 2010. (level of evidence 1A)</ref><ref>ALBAZAZ, R. N., et al., Complex Regional Pain Syndrome: A review. Annals of Vascular Surgery Inc., 2008. (level of evidence 2A)</ref><ref>KENLER, M., et al., The effect of Spinal Cord Stimulation in Patients with Chronic Reflex Sympathetic Dystrophy: Two Years’ Follow-up of the Randomized Controlled Trial. Annals of Neurology, 2004. (level of evidence 1B)</ref> (level of evidence 1B),non-invasive brain stimulation (repetitive transcranial magnetic stimulation).<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref><br>Evidence:<br>-to reduce pain<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref><br>-further trials are required<ref>TRAN, Q., e.a., Treatment of complex regional pain syndrome: a review of the evidence. Canadian Anesthesiologists’ Society, 2010. (level of evidence 1A)</ref>


Examples of spinal cord stimulation in the treatment of CRPS in the lower extremities.<ref>COLLIN, C., Physical Therapy Management of Complex Regional Pain Syndrome I in a 14-Year-Old Patient Using Strain Counterstrain: A Case Report. J Man Manip Ther., 2007. level of evidence 4)</ref> (level of evidence 4)
* '''Cognitive behavioural therapy [[Cognitive Behavioural Therapy|(CBT)]] and graded exposure:''' Particularly valuable, in combination with physiotherapy, to address [[kinesiophobia]]; bearing in mind that a certain level of activity avoidance is not unreasonable.<ref name=":33" /><ref name=":26" /><ref name=":4" />Catastrophic thinking has also been associated with increased pro-inflammatory cytokines which can exacerbate CRPS, and therefore needs to be addressed - education and correction of misconceptions relating to CRPS can be very valuable.<ref name=":33" />
* '''Stress management and [[Mindfulness Techniques For Pain Management|Mindfulness]]:''' Stress can be associated with increased catecholamine release which contributes to central sensitisation<ref name=":33" />
* '''ACT''' (Acceptance and commitment therapy)''':''' Can lead to improved functioning and quality of life, as well as self-efficacy.<ref name=":33" />


<br>7. Other treatments:<br>-Whirlpool bath/ contrast baths<ref>DEVRIMSEL, G., et al., The effects of whirlpool bath and neuromuscular electrical stimulation on complex regional pain syndrome. J. Phys. Ther. Sci., 2015. (level of evidence 3B)</ref> (level of evidence 3B)<br>-Vocational and recreational rehabilitation<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref><br>-Psychological therapies: cognitive-behavioral therapy (CBT), operant conditioning (OC), counselling, pain education and relaxation techniques<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref><ref>TRAN, Q., e.a., Treatment of complex regional pain syndrome: a review of the evidence. Canadian Anesthesiologists’ Society, 2010. (level of evidence 1A)</ref><ref>BRUEHL, S., Psychological interventions. In: Harden RN editor(s). Complex regional pain syndrome: treatment guidelines. Reflex Sympathetic Dystrophy Syndrome Association, 2006 (level of evidence 1C)</ref><br>-[http://www.physio-pedia.com/Acupuncture Acupuncture], electroacupuncture<ref>SMITH, T., How effective is physiotherapy in the treatment of complex regional pain syndrome type I? A review of the literature. Musculoskeletal care, 2005. (level of evidence 3A)</ref> (level of evidence 3A)<br>-Tactile sensory discrimination training<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref><ref>BOWERING, K. J., The effects of graded motor imagery and its components on chronic pain: a systematic review and meta-analysis. The American Pain Society, 2013. (level of evidence 1A)</ref><br>-Weight bearing<ref>TRAN, Q., e.a., Treatment of complex regional pain syndrome: a review of the evidence. Canadian Anesthesiologists’ Society, 2010. (level of evidence 1A)</ref><br>-[http://www.physio-pedia.com/Ultrasound_therapy Ultrasound therapy]<br>-Kinesiotaping<ref>ANANDKUMAR, S.; MANIVASAGAM, M., Multimodal physical therapy management of a 48-year-old female with post-stroke complex regional pain syndrome. Physiother Theory Pract, 2014. (level of evidence 3B)</ref> (level of evidence 3B)
=== CRPS Management in Children ===
In a study of 28 children meeting the IASP criteria for CRPS, 92% reduced or eliminated their pain after receiving exercise therapy. <ref name=":4" />Physiotherapy (hydrotherapy, desensitisation and exercise) combined with CBT/counselling has proven efficacy in treating children with CRPS.<ref name=":4" />  


The conclusion we can make is that a few clinical studies could demonstrate a significant improvement of CRPS after physical therapy.<ref>BIRKLEIN, F., et al., Neurological findings in complex regional pain syndromes—analysis of 145 cases. Acta Neurol Scand, 2000. (level of evidence 2A)</ref><ref>SHERRY, D., et al., Short- and long-term outcomes of children with complex regional pain syndrome type I treated with exercise therapy. Clin J Pain, 1999. (Level of evidence 1B)</ref><ref>OERLEMANS, H., et al., Adjuvant Physical Therapy Versus Occupational Therapy in patients With Reflex Sympathetic Dystrophy/Complex Regional Pain Syndrome type I. Arch Phys Med Rehabil, 2000. (level of evidence 1B)</ref><ref>LEE, B., et al., Physical therapy and cognitive-behavioral treatment for complex regional pain syndromes. Pain Treatment Service, 2002. (level of evidence 2B)</ref><ref>OERLEMANS, H., et al., Pain and reduced mobility in complex regional pain syndrome I: outcome of a prospective randomised controlled clinical trial of adjuvant physical therapy versus occupational therapy. Pain, 1999. (level of evidence 1B)</ref> (level of evidence 1B) But further trials are required for an optimal treatment.<ref>PEREZ, R., Evidence based guidelines for complex regional pain syndrome type 1. BMC Neurology, 2010. (level of evidence 2C)</ref><br>
== Case Reports  ==
[https://pubmed.ncbi.nlm.nih.gov/21737520/ More Than Meets the Eye: Clinical Reflection and Evidence-Based Practice in an Unusual Case of Adolescent Chronic Ankle Sprain]


== Key Research  ==
[https://pubmed.ncbi.nlm.nih.gov/10907896/ Thoracic Spine Dysfunction in Upper Extremity Complex Regional Pain Syndrome Type I]


add links and reviews of high quality evidence here (case studies should be added on new pages using the [[Template:Case Study|case study template]])<br>
== Resources  ==


== Resources <br>  ==
*[https://crps.europeanpainfederation.eu/#/ Eu Pain Federation -] free tool to guide PTs and OTs with designing treatment plans for CRPS
 
*[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9186375/ CRPS Diagnostic and Treatment Guidelines, 5th Edition]
add appropriate resources here <br>
*[https://www.crpsconsortium.org/ International Research Consortium for CRPS (IRC)]
*[https://www.rcplondon.ac.uk/guidelines-policy/complex-regional-pain-syndrome-adults Complex regional pain syndrome in adults (2nd edition) UK guidelines for diagnosis, referral and management in primary and secondary care.] Royal College of Physicians, July 2018.
*[http://www.rsds.org Reflex Sympathetic Dystrophy Syndrome Association]
*[http://www.theacpa.org American Chronic Pain Association]
*[http://www.mayoclinic.com Mayo Clinic]
*[http://www.ninds.nih.gov National Institute of Neurological Disorders and Stroke]


== Clinical Bottom Line  ==
== Clinical Bottom Line  ==


Complex regional pain syndrome (CRPS) is a term for a variety of clinical conditions characterized by chronic persistent pain. There are two types of CRPS: The difference between type I and type II is based on a consensus between clinicians and scientists. All symptoms of CRPS II show many similarities to those of CRPS I.<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref><ref>WASNER, G., e.a., Vascular abnormalities in reflex sympathetic dystrophy (CRPS I): mechanisms and diagnostic value. Oxford University Press, 2001. (level of evidence 3A)</ref><ref>BARON, R., Complex regional pain syndromes. Curr Pain Headache Rep., 2001. (level of evidence 2A)</ref><ref>JANIG, W., et al., Complex regional pain syndrome is a disease of the central nervous system. Clinical Autonomic Research, 2002. (level of evidence 5)</ref> It is difficult to manage CRPS because there is lack of understanding of the pathophysiologic abnormalities and lack of specific diagnostic criteria. In literature there is very low quality evidence to treat CRPS.<ref>O’CONNEL, N.E., e.a., Interventions for treating pain and disability in adults with complex regional pain syndrome- an overview of systematic reviews (Review). The Cochrane Collaboration, 2013. (level of evidence 3A)</ref> The little amount of clinical studies that could demonstrate a significant improvement after physical therapy needs to become more complete by further trials. This is required for an optimal physical management.<br>
CRPS is characterised by debilitating, persistent pain that is disproportionate in magnitude or duration to the typical course of pain after similar injury. It is a difficult condition to treat as the pathophysiology is often complex and diverse and is still not fully understood. High quality, robust evidence regarding effective treatment is still lacking, leading to no consensus regarding the optimal management of CRPS.  
 
== Recent Related Research (from [http://www.ncbi.nlm.nih.gov/pubmed/ Pubmed])  ==
 
see tutorial on [[Adding PubMed Feed|Adding PubMed Feed]]
<div class="researchbox">
<rss>http://eutils.ncbi.nlm.nih.gov/entrez/eutils/erss.cgi?rss_guid=1P7PR1QO6IS9xQ724YOoSHF8On2gkKwiE3UGU6x5C6gE847gBI|charset=UTF-8|short|max=10</rss>
</div>
== References  ==
== References  ==
see [[Adding References|adding references tutorial]].


<references />  
<references />  


[[Category:Vrije_Universiteit_Brussel_Project|Template:VUB]]
[[Category:Vrije_Universiteit_Brussel_Project]]
[[Category:Pain]]
[[Category:Conditions]]
[[Category:Neurological - Conditions]]
[[Category:PPA_Project]]
[[Category:Bellarmine_Student_Project]]
[[Category:Primary Contact]]
[[Category:Syndromes]]

Latest revision as of 12:05, 25 September 2023

Introduction[edit | edit source]

Complex Regional Pain Syndrome (CRPS) is a term for a complex pain disorder characterised by continuing (spontaneous and/or evoked) regional pain that is seemingly disproportionate in time or degree to the usual course of any known trauma or lesion. [1] Specific clinical features include allodynia, hyperalgesia, sudomotor and vasomotor abnormalities, and trophic changes.

CRPS has a multifactorial pathophysiology involving pain dysregulation in the sympathetic and central nervous systems, and possible genetic, inflammatory, and psychological factors.

Many names have been used to describe this syndrome such as; Reflex Sympathetic Dystrophy, causalgia, algodystrophy, Sudeck’s atrophy, neurodystrophy and post-traumatic dystrophy. To standardise the nomenclature, the name complex regional pain syndrome was adopted in 1995 by the International Association for the Study of Pain (IASP).[2]

Classification and Phenotypes[edit | edit source]

CRPS is commonly subdivided into Type I and Type II CRPS. Type I occurs in the absence of major nerve damage (minor nerve damage may be present), while Type II occurs following major nerve damage.[3] Despite this distinction, there is a large overlap in clinical features and the primary diagnostic criteria are identical, and the classification therefore may have little clinical importance.[1] [4][5][6][7]

Three stages (stage I - acute up to 3 months, stage II - dystrophic 3-6- months after onset, stage III - atrophic > 6 months) of CRPS progression have been proposed by Bonica in the past, but the existence of these stages has been suggested as unsubstantiated. [8][9] It is however possible for CRPS subtypes to evolve over time, currently referred to as "warm CRPS" (warm, red, dry and oedematous extremity, inflammatory phenotype) and "cold CRPS" (cold, blue or pale, sweaty and less oedematous, central phenotype). [10] Both of these subtypes present with comparable pain intensity. Warm CRPS is by far the most common in early CRPS, and cold CRPS tends to have a worse prognosis and more persistent symptomatology.[1]

Dimova and associates [11]recentrly proposed another classification based on the findings of the neurological examination. The first group of patients presents with a central phenotype, with motor signs, allodynia, and glove/stocking-like sensory deficits. The second cluster represents a pheripheral inflammation phenotype, involving edema, skin color changes, skin temperature changes, sweating, and trophic changes. The third group has a mixed presentation.

As noted from above, although classification for CRPS shows some variability, there is agreement on mechanisms of central and inflammatory origin. Further research is needed to reach clusters that lead to valid and effective treatment decisions.

Epidemiology[edit | edit source]

Incidence and Prevalence[edit | edit source]

CRPS incidence appears to vary according to global location. For example, studies show that Minnesota has an incidence of 5.46 per 100,000 person-years for CRPS type I and 0.82 per 100,000 person-years for CRPS type II, whilst the Netherlands in 2006 had 26.2 cases per 100,000 person-years. Research shows that CRPS is more common in females than males, with a ratio of 3.5:1.[12] CRPS can affect people of all ages, including children as young as three years old and adults as old as 75 years, but typically is most prevalent in the mid-thirties. CRPS Type I occurs in 5% of all traumatic injuries, with 91% of all CRPS cases occurring after surgery.[13]

Location[edit | edit source]

The location of CRPS varies from person to person, mostly affecting the extremities, occurring slightly more in the lower extremities (+/- 60%) than in the upper extremities (+/- 40%). It can also appear unilaterally or bilaterally.[14]

Prognosis[edit | edit source]

Approximately 15% of early CRPS (up to 6-18 months duration) fail to recover and early onset of cold CRPS predicts poor recovery.[1]

Aetiology[edit | edit source]

Complex regional pain syndrome can develop after the occurrence of different types of injuries, such as:

  • Minor soft tissue trauma (sprains)
  • Surgeries
  • Fractures, especially following immobilisation
  • Contusions
  • Crush injuries
  • Nerve lesions
  • Stroke

The onset is mostly associated with a trauma, immobilisation, injections, or surgery, but there is no relation between the grade of severity of the initial injury and the following syndrome. In 7% of cases there is no injury or surgery preceding the onset of CRPS.

A study found that excessive baseline pain (>5/10) in the week following wrist fracture surgery increases the risk of developing CRPS. [15] A stressful life and other psychological factors may be potential risk factors that impact the severity of symptoms in CRPS. [16]There is however no compelling evidence that psychiatric disorders contribute to the development of CRPS. [1]

Pathophysiology[edit | edit source]

Teasdall et al-2.jpg

Various mechanisms are at play in the development and maintenance of CRPS, including nerve injury, central and peripheral sensitisation, altered sympathetic function, inflammatory and immune factors, brain changes, genetic factors and psychological factors.[17] Little is however known about how these mechanisms interact and it is likely that the relative contribution of each mechanism varies between patients. [18]

CRPS usually follows trauma/surgery, and likely starts with normal peripheral nociceptive stimulation. Enhanced, altered and ongoing nociception can then lead to peripheral and central sensitisation (CS), with the latter regarded as a prominent mechanism underlying CRPS.[4][19]

Sustained neuroinflammation has lately received attention as a key factor in the initiation and perpetuation of CRPS. [18] Neuropeptides mediate the enhanced neurogenic inflammation and pain; they may activate microglia and astrocytes, resulting in a cascade of events that sensitise neurons and impact synaptic plasticity. [18] Upregulated cytokines, secreted by keratinocytes, exacerbate this phenomenon. [18] Immune cells may also modulate neuronal activity by releasing immunomodulatory factors. [18]

Psychological factors could maintain CRPS by their impact on catecholamine release and kinesiophobia. The central and peripheral nervous systems are connected through neural and chemical pathways, and can have direct control over the autonomic nervous system. It is for this reason that there can be changes in vasomotor and sudomotor responses without any impairment in the peripheral nervous system. For a more detailed review of the underlying mechanisms at play, see this article by Bruehl (2015).

Treatment approaches are aimed at normalising afferent inputs and reversing secondary changes associated with immobilisation.

Figure 1. Nociceptive (painful) information is relayed through the dorsal horn of the spinal cord for processing and modulation before cortical evaluation. [20]

Video below: more on the pathophysiology underlying CRPS.

Clinical Presentation[edit | edit source]

CRPS is clinically characterised by sensory, autonomic, and motor disturbances. The table below shows an overview of these characteristics. [2] [4] [21] [6] [7] [22]

Features of CRPS
Sensory disturbances Allodynia and hyperalgesia

Hypoesthesia; Strange, disfigured or dislocated feeling in the limb[12]

Autonomic and inflammatory components Swelling and oedema[12]

Hyperhidrosis; changes in sweating Abnormal skin blood flow Temperature changes[12] Colour changes (redness or pale)

Trophic changes Thick, brittle, or rigid nails

Increased/decreased hair growth Thin, glossy, clammy skin[12] Osteopenia (chronic stage)

Motor dysfunction Weakness of multiple muscles and atrophy [12]

Inability to initiate movement of the extremity Stiffness and reduced ROM Tremor or dystonia

Pain Burning, deep, dull

Disproportionate Spontaneous and/or triggered by movement, noise, pressure on joint Pain may not be present in 7% of CRPS patients[12]


Symptoms can spread beyond the area of the lesioned nerve in Type II. Ongoing neurogenic inflammation, vasomotor dysfunction, central sensitisation and maladaptive neuroplasticity contribute to the clinical phenotype of CRPS. [6] [14]

Associated Co-morbidities[edit | edit source]

CRPS may also be associated with:

Differential Diagnosis[edit | edit source]

Differential diagnosis includes the direct effects of the following conditions: [13][29]

Diagnostic Procedures[edit | edit source]

CRPS diagnosis is mainly based on patient history, clinical examination, and supportive investigations.

There are 4 diagnostic tools for CRPS in adult populations. These include the Veldman criteria, IASP criteria, Budapest Criteria, and Budapest Research Criteria.[30]

The Budapest Criteria[edit | edit source]

The Budapest criteria (also known as the IASP criteria and explicitly endorsed by the IASP) has been developed for the diagnosis of CRPS, but improvements still need to be made. [31][32][33] Clinical diagnostic criteria for CRPS are: [1]

  1. Continuing pain, which is disproportionate to any inciting event
  2. Must report at least one symptom in three of the four following categories:
    • Sensory: hyperalgesia and/or allodynia
    • Vasomotor: temperature asymmetry and/or skin colour changes and/or skin colour asymmetry
    • Sudomotor/oedema: oedema and /or sweating changes and/or sweating asymmetry
    • Motor/trophic: decreased range of motion and/or motor dysfunction (weakness, tremor, dystonia) and/or trophic changes (hair, nail, skin)
  3. Must display at least one sign at the time of evaluation in two or more of the following categories
    • Sensory: hyperalgesia (to pinprick) and/or allodynia (to light touch/pressure/joint movement)
    • Vasomotor: evidence of temperature asymmetry and/or skin colour changes and/or skin colour asymmetry
    • Sudomotor/oedema: evidence of oedema and /or sweating changes and/or sweating asymmetry
    • Motor/trophic: evidence of decreased range of motion and/or motor dysfunction (weakness, tremor, dystonia) and/or trophic changes (hair, nail, skin)
  4. There is no other diagnosis that better explains the signs and symptoms

The Budapest Criteria have excellent diagnostic sensitivity of 99% and a moderate specificity of 68%. [30] See the video below for more detail on the Budapest Criteria.

[34]

Other Tests[edit | edit source]

  • Infrared Thermography: Infrared thermography (IRT) is an effective mechanism to find significant asymmetry in temperature between both limbs by determining if the affected side of the body shows vasomotor differences in comparison to the other side. It is reported having a sensitivity of 93% and a specificity of 89%. [35] This test is hard to obtain so it is not often used for diagnosing of CRPS. [32] [36][35]
  • Sweat Testing: Determining if the patient sweats abnormally. Q-sweat is an adequate instrument to measure sweat production. The sweat samples should be taken from both sides of the body at the same time. [4][35]
  • Radiographic testing: Irregularities in the bone structure and osteopenia of the affected side of the body can become visible with the use of X-rays. [4] [35]
  • Three phase bone scan: A triple phase bone scan is the best method to rule out Type I CPRS. [37] With the use of technetium Tc 99m-labeled bisophosphonates, an increase in bone metabolism can be shown. Higher uptake of the substance means increased bone metabolism and the body part could be affected. [35] The triple-phase bone scan has the best sensitivity, NPV, and PPV compared to MRI and plain film radiographs.
  • Bone densitometry: An affected limb often shows less bone mineral density and a change in the content of the bone mineral. During treatment of the CPRS the state of the bone mineral will improve. So this test can also be used to determine if the patient’s treatment is effective. [35]
  • Magnetic Resonance Imaging (MRI): MRI scans are useful to detect periarticular marrow oedema, soft tissue swelling and joint effusions. And in a later stage, atrophy and fibrosis of periarticular structures can be detected. But these symptoms are not exclusively signs of CRPS. [4][35]

Outcome Measures[edit | edit source]

The CRPS consortium has established a list of core outcome measures to be used for patients with CRPS (referred to as COMPACT).[38]

Patient reported Outcome Measures:

Clinical reported Outcome Measures:

  • CRPS Severity Score (CSS): Includes 8 signs and 8 symptoms that reflect the sensory, vasomotor, sudomotor/edema and motor/trophic disorders of CPRS, coded based on the history and physical examination. Extent of changes in CSS scores over time are significantly associated with changes in pain intensity, fatigue, and functional impairments. Thus, the CSS appears to be valid and sensitive to change. A change of 5 or more CSS scale points reflects a clinically-significant change. [1]

Other Outcome Measures (not part of COMPACT):

  • Various region specific functional measures can be used for either upper limb or lower limb CRPS, eg. Grip strength [39]

Examination[edit | edit source]

The diagnosis is based on the clinical presentation described above. Procedures start with taking a detailed medical history, taking into account any initiating trauma and any history of sensory, autonomic, and motor disturbances, as well as how the symptoms developed, the time frame, distribution and characteristics of pain. Assessment for any swelling, sweating, trophic and/or temperature increases, and motor abnormality in the disturbed area is important. Skin temperature differences may be helpful for diagnosis of CRPS. The original IASP criteria required only a history and subjective symptoms for a diagnosis of CRPS, but recent consensus guidelines have argued for the inclusion of objective findings. [40]

The clinical presentation of CRPS, and the underlying mechanisms, can differ between patients and even within a patient over time - it is therefore important assess underlying pain mechanisms in order to design targeted treatment for each individual.[1]

  1. Autonomic Dysfunction: The majority of patients with CRPS have bilateral differences in limb temperature and the skin temperature depends of the chronicity of the disease. In the acute stages, temperature increases are often concomitant with a white or reddish colouration of the skin and swelling. where the syndrome is chronic, the temperature will decrease and is associated with a bluish tint to the skin and atrophy. [41]
  2. Motor Dysfunction: Studies have shown that approximately 70% of the patients with CRPS show muscle weakness in the affected limb, exaggerated tendon reflexes or tremor, irregular myoclonic jerks, and dystonic muscle contractions. Muscle dysfunction often coincides with a loss of range of motion in the distal joints. [42]
  3. Sensory Dysfunction: The distal ends of the extremities require attention when examining a patient with CRPS. However, common findings of regional neuropathic and motor dysfunction have shown us that it is important to broaden the examination both proximally and contralaterally. [41]Light touch, pinprick, temperature and vibration sensation should be assessed for a complete picture of the CRPS. [41] Most assessments are interlinked, for example, when vibration sensation is highly positive, light touch should also be positive. [41]To help distinguish the findings of a sensory dysfunction, bilateral comparisons are made. [42][41]Also see Quantitative Sensory Testing.

Multidisciplinary Management[edit | edit source]

CRPS can be very difficult to treat successfully, as it involves both central and peripheral pathophysiology, as well as frequent psychosocial components.[1] This complexity of CRPS calls for an interdisciplinary approach, where the entire management team collaborates and focuses on all the relevant biopsychosocial elements. In many settings this is not feasible - in such cases a multidisciplinary approach is still very important to address the multifactorial nature of CRPS.[1] Treatment of complex regional pain syndrome should be immediate, and most importantly directed toward functional restoration. Functional restoration emphasises physical activity, desensitisation and normalisation of sympathetic tone, and involves steady progression. [1]

Treatment Overview[edit | edit source]

Despite multiple interventions being described and commonly used, the optimal management of CRPS is still under debate. The latest published evidence from Cochrane and non‐Cochrane systematic reviews of the efficacy, effectiveness, and safety interventions did not identify high‐certainty evidence for the effectiveness of any therapy for CRPS. [43] This paper was the first update of the original Cochrane review in 2013. [43]

Nevertheless, the following table summarises treatment recommendations for CRPS. These strategies are based on the Malibu CRPS algorithm and most recent treatment guidelines.[1]

CRPS treatment overview
Description & Modalities Team members
Functional Restoration
Phase 1: Activation of pre-sensorimotor cortices Graded motor imagery

Visual tactile discrimination

PT/OT
Phase 2: Gentle active ROM Progressive AROM

Isometric strengthening

PT
Phase 3: Weight bearing UL: carrying items

LL: partial weight bearing

PT/OT
Desensitisation Progressive stimulation with textures (soft to more rough)

Contrast baths with progressive broadening of the temp difference

OT/PT
Pain Management Sympathetic blocks and/or medication to allow engagement with functional restoration

Functional restoration addresses pain by normalising afferent inputs and central processing

MD

PT

Edema Management Pressure garments

Aquatic therapy General aerobic activity

PT/OT
Psychological approaches CBT and exposure-based therapy if patient presents with kinesiophobia

Psychotherapy if depression/anxiety is present

Psych/PT
Secondary impairments Local muscle spasm, reactive bracing and disuse atrophy secondary to pain needs to be addressed PT

Medical Management[edit | edit source]

Medical management is aimed at achieving sufficient pain relief, in order to allow for rehabilitation interventions to commence and progress. Most medications used for CRPS lack high quality evidence, and most treatment regimes are extrapolated from evidence for related neuropathic conditions. CRPS does however differ from other neuropathic conditions in that additional circulatory, bone and inflammatory pathways are present[1]. Patients also present with a varying dominant mechanisms (including central sensitisation, motor abnormalities and sympathetic abnormalities), and it is therefore important to base medication prescription on reasoning regarding evident underlying mechanisms. Below is a summary of the possible medical interventions for patients with CRPS:

Medical interventions for CRPS[1]
Description Evidence/ considerations
Pharmacotherapy
Anti-inflammatory drugs NSAIDs (esp Ketoprofen), COX-2 inhibitors, corticosteroids Useful to address the inflammatory component of CRPS, but often not effective as neurogenic inflammation mostly dominant. Risks regarding long-term use needs to be considered
Biphosponates Have immune-modulatory properties and modulate bone metabolism May help in acute stages or in selected subtypes of CRPS (where osteopenia is evident), but the evidence is lacking
Cation-Channel blockers Anticonvulsants (gabapentin/pregabalin) Proven efficacy for other neuropathic pain conditions; evidence for CRPS is lacking
Tricyclic drugs Anti-depressants that augment descending inhibition Effective for other neuropathic conditions; worth considering in patients with associated insomnia, depression and/or anxiety
Opioids Tramadol

Methadone

Tolerance and long-term toxicity are important concerns, and can worsen allodynia and hyperalgesia; daily use is not recommended in CRPS - only for excruciating pain
NMDA Antagonists Ketamine High risk of toxicity; IV ketamine may have positive effects on central sensitisation
Alpha2-adrenergic Agonists/ Ca-channel blockers Clonidine

Nifedipine

Evidence is contradictory. Adverse effects can occur
Calcitonin Hormone produced by the thyroid A meta-analysis demonstrated benefits of intranasal administration, but subsequent studies had conflicting results
Immune modulators Steroids

Immunoglobulins (IVIG)

Evidence suggests that early initiation (after trauma), followed by tapering, may be effective

Steroid injections are ineffective IVIG has limited evidence

Other
Topical treatment Lidocaine

Capsaicin

Capsaicin can be intolerably painful in the presence of hyperalgesia
Supplements Vitamin C Daily Vit C following limb fracture or surgery may prevent CRPS
Sympathetic blocks Local anaesthetic block applied at the transverse process of C6 or L2/3 High quality evidence is lacking, but may be useful for a subset of patients with prominent vasomotor dysfunction, to provide pain relief and a window of opportunity for rehabilitation techniques[1][35]
Spinal cord stimulations Aims to inhibit the nociceptive pathways at the level of the dorsal column Reserved for use when patients are not responding to other interventions. Safe and proven long-term effective for chronic CRPS[1]
Dorsal root ganglion stimulation[3] Aims to modulate nociceptive pathways at the dorsal root Evidence shows reduced pain, improved quality of life and function if conservative therapy has failed[1]

It is likely that medication prescription will need to be adapted over time as CRPS progresses or patients develop tolerance. The following table presents a consensus-based pharmacotherapy guide based on clinical findings in CRPS: [1]

Reason for inability to start/progress with rehab Pharmacotherapy reccommendations
Mild to moderate pain Simple analgesics and/or blocks
Excruciating pain Opioids and/or blocks
Inflammation and oedema Steroids, NSAIDs, immune modulators
Depression, insomnia Anti-depressants
Severe allodynia/hyperalgesia Anticonvulsants and/or NMDA antagonists
Osteopenia and trophic changes Calcitonin or biphosphonates
Profound vasomotor disturbance Calcium channel blockers and/or blocks

Physiotherapy Management[edit | edit source]

Various consensus groups have emphasised that physiotherapy is of utmost importance in restoring function in patients with CRPS.[4][1] Studies have shown that exercise-based physiotherapy is effective in managing pain and reducing impairment. [1][44]

Physiotherapy aims to restore function, using the following intervention strategies:

  • Graded Motor Imagery (GMI): Aims to address altered central processing by restoring the mismatch between afferent input and central representation. A meta-analysis demonstrated very good evidence for the efficacy of GMI in combination with medical management in patients with CRPS-1, with many studies indicating improvements in pain and function.[2][5][45][46]
    Mirror therapy.jpg
  • Mirror visual feedback (MVF): Proven to be effective in patients with CRPS-1 and for stroke patients with CRPS.[1] [47][5]It is critical that the patient 'believes' the illusion.
  • Tactile sensory discrimination training [5][48]
  • Progressive strengthening: Starting with isometrics, and then gently progressing isotonic and resisted movements.[5]
  • Education and pacing: Patients need to be told that both too much and too little movement can increase pain, and physiotherapists need to help patients to find a "happy medium", while guiding them towards more function.[1]Incorporating pain neuroscience education (PNE) elements can help reduce kinesiophobia by explaining that pain does not signal tissue damage.[1]
  • Flexibility/ROM exercises: Active ROM and functional movements, while maintaining good movement patterns. Bilateral movements and conscious attention to the limb should be encouraged. [12]Graded exposure can help to reduce kinesiophobia.
  • Aquatic therapy: Allows activities to be performed with decreased weight bearing on the lower extremities, which can be a tolerable way of introducing weight bearing/resistance exercises. Hydrostatic pressure also provides gentle compression around the joints which can reduce oedema.[1]
  • Desensitisation: Consist of giving stimuli of different fabrics, different pressures (light or deep), vibration, tapping, heat or cold. See OT section [12][1]
  • Gradual weight bearing: Exposure the affected extremity to gradually increasing weight bearing activities. Gait training should be included for lower limb CRPS. [12][1][2][49]
  • TENS: Evidence is lacking, but may have some benefit[1]

Physiotherapists should avoid aggressive exercises, prolonged application of ice and prolonged rest/inactivity - these can exacerbate symptoms.[1] Massage lacks evidence, but may be useful in oedema management if applied carefully.[1][2][5]

Since the mechanisms underlying CRPS are often widespread, it may be beneficial to involve unaffected extremities during exercises, especially when moving the affected extremity is too painful.[24]

Occupational Therapy Management[edit | edit source]

Occupational therapists (OTs) are pivotal in the functional restoration process as experts in biopsychosocial principles and functional assessment. The role of the OT involves initial functional evaluation (including ROM, coordination, dexterity, pain, sensation and use of the extremity during ADLs), followed by various intervention strategies, including:

  • GMI and Mirror visual feedback
  • Desensitisation: Involves graded exposure to textures (from soft to more textured). Aids in normalisation of cortical organisation in CRPS patients by restoring the sensory cortex[1][50]
  • Oedema Management: Using specialised garments and manual oedema mobilisation. [1]
  • Splinting: May be indicated in severe cases to promote improved circulation to the area and to facilitate more normal positioning. Symptoms can be exacerbated by splinting and should therefore be closely monitored.[1]
  • Stress loading: This involves active movement and compression of the affected joints, and although it may at first increase symptoms, this is usually followed by reduced pain and swelling. It consists of: [1]
    • Scrubbing - moving the affected extremity back/forth while weight bearing through the extremity, using a scrub brush in the quadruped position/sitting
    • Carrying - small objects carried in the hand throughout the day, progressing to heavier items (UL); weight shifting, walking, standing with one foot on step, ball tossing towards the affected limb (LL)
  • Functional retraining: Graded increase in functional use of the extremity as pain allows to increase independence in ADLs. Can be facilitated with PNF pattern strengthening
  • Vocational rehabilitation and reintegration: Job site analysis, job specific conditioning/ work hardening, work capacity evaluation and transferable skills analysis.[1][5]
  • Contrast baths: Mild contrast baths may be useful in the early stages of CRPS to improve circulation. In more advanced CRPS, vasomotor changes interfere with these effects and cold water emersion can exacerbate symptoms. It is therefore usually not recommended in patients with CRPS.[1]

Psychotherapy[edit | edit source]

In CRPS, psychological factors are important to target to ensure optimal outcomes. Solely treating psychological aspects is however not sufficient, as clear biological elements exist in CRPS - evidence suggests that psychological interventions are most effective when combined with physiotherapy.[1]

There is currently no compelling evidence that psychiatric disorders contribute to the development of CRPS, but as a chronic pain condition, depression and distress can be common in these patients. [1]The aim of psychological interventions should be to address any factors that interfere with functional progression and to assist the psychological impact of a continued, severe pain experience[1].

  • Cognitive behavioural therapy (CBT) and graded exposure: Particularly valuable, in combination with physiotherapy, to address kinesiophobia; bearing in mind that a certain level of activity avoidance is not unreasonable.[1][5][44]Catastrophic thinking has also been associated with increased pro-inflammatory cytokines which can exacerbate CRPS, and therefore needs to be addressed - education and correction of misconceptions relating to CRPS can be very valuable.[1]
  • Stress management and Mindfulness: Stress can be associated with increased catecholamine release which contributes to central sensitisation[1]
  • ACT (Acceptance and commitment therapy): Can lead to improved functioning and quality of life, as well as self-efficacy.[1]

CRPS Management in Children[edit | edit source]

In a study of 28 children meeting the IASP criteria for CRPS, 92% reduced or eliminated their pain after receiving exercise therapy. [44]Physiotherapy (hydrotherapy, desensitisation and exercise) combined with CBT/counselling has proven efficacy in treating children with CRPS.[44]

Case Reports[edit | edit source]

More Than Meets the Eye: Clinical Reflection and Evidence-Based Practice in an Unusual Case of Adolescent Chronic Ankle Sprain

Thoracic Spine Dysfunction in Upper Extremity Complex Regional Pain Syndrome Type I

Resources[edit | edit source]

Clinical Bottom Line[edit | edit source]

CRPS is characterised by debilitating, persistent pain that is disproportionate in magnitude or duration to the typical course of pain after similar injury. It is a difficult condition to treat as the pathophysiology is often complex and diverse and is still not fully understood. High quality, robust evidence regarding effective treatment is still lacking, leading to no consensus regarding the optimal management of CRPS.

References[edit | edit source]

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