BACKGROUND:Complex regional pain syndrome (CRPS) is much more prevalent in women than men but potential differences in clinical phenotype have not been thoroughly explored to date. Differences in the clinical presentation between sexes may point at new avenues for a more tailored management approach of CRPS. We therefore explored if in CRPS, the patient's sex is associated with differences in clinical and psychological characteristics.METHODS:In this cross-sectional study of 698 CRPS patients (599 females) fulfilling the Budapest clinical or research criteria, CRPS signs and symptoms, CRPS severity, pain (average pain intensity in the previous week and McGill pain rating index), pain coping (Pain Coping Inventory), physical limitations (Radboud Skills Questionnaire (upper limb), Walking and Rising questionnaire (lower limb)), anxiety and depression (Hospital Anxiety and Depression scale) and kinesiophobia (Tampa scale for kinesiophobia) were evaluated.RESULTS:Male CRPS patients used more often extreme words to describe the affective qualities of pain, used more passive pain coping strategies, and were more likely to suffer from depression and kinesiophobia.CONCLUSION:Sex-related differences are present in CRPS, but the effect is generally small and mainly concerns psychological functioning. A greater awareness of sex-specific factors in the management of CRPS may contribute to achieving better outcomes.SIGNIFICANCE:What is known? Nonsex-specific clinical data of CRPS patients. What is new? Male CRPS patients used more often extreme words to describe the affective qualities of pain, used more passive pain coping strategies, and were more likely to suffer from depression and kinesiophobia.

Das komplexe regionale Schmerzsyndrom (CRPS) Typ 1 ist charakterisiert durch spontan auftretende Schmerzen, Allodynie und Hyperalgesie und betrifft Frauen häufiger als Männer. Patienten mit diesem Krankheitsbild leiden daneben unter massiven Funktionsstörungen.

Objectives: The aim of this cross-sectional study was to evaluate to what extent pain coping and kinesiophobia contribute to limitations in activity and participation in patients with complex regional pain syndrome type 1 (CRPS-1) of the lower limbs. Methods: A total of 238 patients with CRPS-1 of the legs from 4 pain clinics and 1 Department of Neurology of University Hospitals participated in this study. Pain and CRPS severity were assessed with the pain rating index of the McGill Pain Questionnaire and the CRPS Severity Score, respectively. Activity was measured with the Rising & Walking scale, and participation with the Social Functioning scale of the SF-36. In addition, the Tampa Scale for Kinesiophobia and Pain Coping Inventory were administered. Hierarchical linear regression was used to evaluate to what extent kinesiophobia and pain coping contributed to difficulties with Rising & Walking and Social Functioning. Results: The analyses showed that the “resting” subscale of the Pain Coping Inventory—that is, 1 of the 3 scales evaluating passive pain coping strategies—contributed significantly to difficulties in rising and walking (explaining 12.5% of the variance) and to difficulties in social functioning (explaining 6.5%), whereas kinesiophobia was not associated with either of these measures. Discussion: These findings indicate that making use of “resting” as a pain coping strategy contributes significantly to limitations in activity and participation in patients with CRPS-1 of the legs. Indications for a negative influence of kinesiophobia or a positive influence of an active pain coping style were not found.

There are limited data available on health-related quality of life (QoL) in patients with complex regional pain syndrome (CRPS). In the present study we examined QoL in 975 CRPS patients attending 6 different clinics in the Netherlands. QoL was assessed using the MOS 36-Item Short-Form Health Survey (SF-36) with the Mental Health Summary Score (MHS) and the Physical Health Summary Score (PHS) as dependent variables. The influences of gender, type of affected limb, disease duration, pain scores, CRPS severity and set of diagnostic criteria used were investigated. We found the lowest scores of QoL in the physical domains of the SF-36, with lower-limb CRPS patients reporting poorer results than patients with an affected upper limb. Influence of gender on QoL was not observed, and correlations of QoL with disease duration and the CRPS severity score were weak. Pain correlated moderately with QoL. In addition, patients fulfilling stricter diagnostic criteria (ie, the Budapest criteria) had lower QoL scores than patients fulfilling less strict criteria (ie, the Orlando criteria). We conclude that loss of QoL in CRPS patients is due mainly to reduced physical health. A comparison with data available from the literature shows that CRPS patients generally report poorer QoL than patients with other chronic pain conditions, particularly in the physical domains. Pain correlated moderately with QoL and therefore deserves ongoing attention by physicians. Finally, patients meeting the diagnostic Budapest criteria have lower QoL scores than patients meeting the Orlando criteria, highlighting the impact of different sets of criteria on population characteristics. (C) 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Background Sympathetic blockade with local anesthetics is used frequently in the management of complex regional pain syndrome type 1(CRPS-1), with variable degrees of success in pain relief. The current study investigated which signs or symptoms of CRPS-1 could be predictive of outcome. The incidence of side effects and complications of sympathetic blockade also were determined prospectively. Methods A prospective observational study was done of 49 patients with CRPS-1 in one extremity only and for less than 1-yr duration who had severe pain and persistent functional impairment with no response to standard treatment with medication and physical therapy. Results Fifteen (31%) patients had good or moderate response. The response rate was not different in patient groups with cold or warm type CRPS-1 or in those with more or less than 1.5°C differential increase in skin temperature after sympathetic blockade. Allodynia and hypoesthesia were negative predictors for treatment success in CRPS-1. There were no symptoms or signs of CRPS-1 that positively predicted treatment success. A majority of patients (84%) experienced transient side effects such as headache, dysphagia, increased pain, backache, nausea, blurred vision, groin pain, hoarseness, and hematoma at the puncture site. No major complications were reported. Conclusions The presence of allodynia and hypoesthesia are negative predictors for treatment success. The selection of sympathetic blockade as treatment for CRPS-1 should be balanced carefully between potential success and side effect ratio. The procedure is as likely to cause a transient increase in pain as a decrease in pain. Patients should be informed accordingly.

Introduction Complex regional pain syndrome type 1 (CRPS-1) has a 31% probability of becoming chronic. The early use of spinal cord stimulation (SCS) has been recommended as a strategy to prevent chronicity and functional impairment. Methods In a prospective study, we treated 74 CRPS-1 patients with a mean disease duration of 17 weeks with standard therapy consisting of physical therapy, topical dimethyl sulfoxide, analgesics, transcutaneous stimulation, and sympathetic blockade. Patients who did not respond to standard therapy were offered a treatment with SCS. In these patients, we investigated the impact on pain, quality of life, and function. Results Out of these 74 patients treated with standard therapy, six patients were included for early SCS treatment. The overall mean pain relief after one year was 35%. The mental component of the Short Form 36 improved; however, there was no effect on the physical component. None of the SCS treated patients showed a clear improvement in functional outcome. Discussion We conclude that the feasibility of performing a randomized controlled trial on early SCS therapy in CRPS-1 is low because of the good disease improvement with standard therapy in the first year after onset. This study raises questions about the need to use SCS early in the course of CRPS-1 because of the probable lack of additional benefit compared with SCS in chronic CRPS-1.

The aim of the present study was to describe the occurrence of signs and symptoms in CRPS I patients meeting the IASP (Orlando) criteria, assess the occurrence of signs and symptoms in relation to disease duration and compare these to historical data based on a different diagnostic criteria set.

Pain PracticeVolume 11, Issue 5 p. 506-507 LETTERS TO THE EDITOR In Response: Intravenous Regional Guanethidine for Complex Regional Pain Syndrome Frank van Eijs MD, Frank van Eijs MD St. Elisabeth Hospital, Tilburg, The NetherlandsSearch for more papers by this authorFrank Huygen MD, PhD, FIPP, Frank Huygen MD, PhD, FIPP Erasmus University Medical Centre, Rotterdam, The NetherlandsSearch for more papers by this authorJan Van Zundert MD, PhD, FIPP, Jan Van Zundert MD, PhD, FIPP Maastricht University Medical Centre, The Netherlands Hospital Oost-Limburg, Genk, BelgiumE-mail: [email protected]Search for more papers by this author Frank van Eijs MD, Frank van Eijs MD St. Elisabeth Hospital, Tilburg, The NetherlandsSearch for more papers by this authorFrank Huygen MD, PhD, FIPP, Frank Huygen MD, PhD, FIPP Erasmus University Medical Centre, Rotterdam, The NetherlandsSearch for more papers by this authorJan Van Zundert MD, PhD, FIPP, Jan Van Zundert MD, PhD, FIPP Maastricht University Medical Centre, The Netherlands Hospital Oost-Limburg, Genk, BelgiumE-mail: [email protected]Search for more papers by this author First published: 16 September 2011 https://doi.org/10.1111/j.1533-2500.2011.00483.xRead the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. References 1 de Mos M, Laferriere A, Millecamps M, et al. Role of NFkappaB in an animal model of complex regional pain syndrome-type I (CRPS-I). J Pain. 2009; 10: 1161–1169. 2 Coderre TJ. Complex regional pain syndrome: what’s in a name? J Pain. 2011; 12: 2–12. 3 Ochoa JL. Letter to the Editor of Pain on Jorum et al.: catecholamine-induced excitation of nociceptors in sympathetically maintained pain. Pain. 2007; 127: 296–301. Pain. 2007;131:226–228; author reply 228. 4 Campero M, Bostock H, Baumann TK, Ochoa JL. A search for activation of C nociceptors by sympathetic fibers in complex regional pain syndrome. Clin Neurophysiol. 2010; 121: 1072–1079. 5 Macefield VG. A role for the sympathetic nervous system in sympathetically maintained pain? Clin Neurophysiol. 2010; 121: 996–997. 6 Dworkin RH, Turk DC, Wyrwich KW, et al. Interpreting the clinical importance of treatment outcomes in chronic pain clinical trials: IMMPACT recommendations. J Pain. 2008; 9: 105–121. Volume11, Issue5September/October 2011Pages 506-507 ReferencesRelatedInformation

Complex Regional Pain Syndrome (CRPS) usually develops after a noxious event, but spontaneous onsets have been described in 3-11% of the cases. The existence of spontaneous-onset CRPS is highly debated and the aim of the present study was therefore to compare the phenotypic characteristics of CRPS patients with a spontaneous onset, with those of patients with a trauma-induced onset.Data of 537 CRPS patients followed up at four departments of anesthesiology were analyzed and comprised 498 (93%) patients with and 39 (7%) patients without a known eliciting event. There where no significant differences between the two groups in gender, or in onset in upper or lower limb or left or right side of the body. Compared to CRPS patients with a trauma-induced onset, spontaneous-onset cases were on average 9 years younger at disease onset and had a 1.4 years longer median disease duration. No significant differences in frequency were found for any of the 34 compared signs and symptoms when the effect of multiple testing was controlled. In conclusion, CRPS may develop both with and without a precipitating noxious event, with both groups exhibiting a largely similar clinical presentation. Spontaneous-onset CRPS patients generally develop the syndrome at a younger age, possibly indicating a susceptibility to develop the condition. The longer disease duration in spontaneous-onset cases may reflect a more gradual disease onset, poorer prognosis, or a delay in diagnosis, possibly as a result of reluctance to make this diagnosis in the absence of a clear initiating event. (C) 2009 European Federation of International Association for the Study of Pain Chapters. Published by Elsevier Ltd. All rights reserved.

Complex regional pain syndrome (CRPS), formerly known as reflex sympathetic dystrophy is a pain syndrome with an unclear pathophysiology and unpredictable clinical course. The disease is often therapy resistant, the natural course not always favorable. The diagnosis of CRPS is based on signs and symptoms derived from medical history and physical examination. Pharmacological pain management and physical rehabilitation of limb function are the main pillars of therapy and should be started as early as possible. If, however, there is no improvement of limb function and persistent severe pain, interventional pain management techniques may be considered. Intravenous regional blocks with guanethidine did not prove superior to placebo but frequent side effects occurred.Therefore this technique receives a negative recommendation (2 A-). Sympathetic block is the interventional treatment of first choice and has a 2 B+ rating. Ganglion stellatum (stellate ganglion) block with repeated local anesthetic injections or by radiofrequency denervation after positive diagnostic block is documented in prospective and retrospective trials in patients suffering from upper limb CRPS. Lumbar sympathetic blocks can be performed with repeated local anesthetic injections. For a more prolonged lumbar sympathetic block radiofrequency treatment is preferred over phenol neurolysis because effects are comparable whereas the risk for side effects is lower (2 B+). For patients suffering from CRPS refractory to conventional treatment and sympathetic blocks, plexus brachialis block or continuous epidural infusion analgesia coupled with exercise therapy may be tried (2 C+). Spinal cord stimulation is recommended if other treatments fail to improve pain and dysfunction (2 B+). Alternatively peripheral nerve stimulation can be considered, preferentially in study conditions (2 C+).

Background: Spinal cord stimulation (SCS) has proven to be an effective however an invasive and relatively expensive treatment of chronic Complex Regional Pain Syndrome type 1(CRPS-1). Furthermore, in one third of CRPS-1 patients, SCS treatment fails to give significant pain relief and 32-38% of treated patients experience complications. The aim of the current study was to develop effective prognostic factors for prediction of successful outcome of SCS.Methods and results: The study population consisted of 36 chronic CRPS patients enrolled in a randomized controlled trial of SCS efficacy. We analyzed various prognostic factors in the group of patients treated with SCS and compared baseline values of possible predictors of outcome in the successfully treated and the not successfully treated group. Success was defined as Patient Global Perceived Impression of Change score of at least "much improved" and pain reduction of at least 2.5 on a visual-analogue scale (VAS score 0-10). Univariate analyses showed that patient age, duration of the disease, localization of the disease, intensity of the pain, and the presence of mechanical hypoesthesia did not predict SCS success. The mean and maximum value of brush-evoked allodynia proved to be statistically significant predictors of outcome. Using Receiver-Operating Characteristic (ROC) curve analyses of maximum allodynia values, the diagnostic sensitivity for successful SCS was 0.75 and the specificity 0.81.Conclusion: Brush-evoked allodynia may be a significant negative prognostic factor of SCS treatment outcome after 1 year in chronic CRPS-1. (C) 2009 European Federation of International Association for the Study of Pain Chapters. Published by Elsevier Ltd. All rights reserved.