Roberto S.G.M. Perez

Validation of proposed diagnostic criteria (the “Budapest Criteria”) for Complex Regional Pain Syndrome

&NA; Current IASP diagnostic criteria for CRPS have low specificity, potentially leading to overdiagnosis. This validation study compared current IASP diagnostic criteria for CRPS to proposed new diagnostic criteria (the “Budapest Criteria”) regarding diagnostic accuracy. Structured evaluations of CRPS‐related signs and symptoms were conducted in 113 CRPS‐I and 47 non‐CRPS neuropathic pain patients. Discriminating between diagnostic groups based on presence of signs or symptoms meeting IASP criteria showed high diagnostic sensitivity (1.00), but poor specificity (0.41), replicating prior work. In comparison, the Budapest clinical criteria retained the exceptional sensitivity of the IASP criteria (0.99), but greatly improved upon the specificity (0.68). As designed, the Budapest research criteria resulted in the highest specificity (0.79), again replicating prior work. Analyses indicated that inclusion of four distinct CRPS components in the Budapest Criteria contributed to enhanced specificity. Overall, results corroborate the validity of the Budapest Criteria and suggest they improve upon existing IASP diagnostic criteria for CRPS.

Evidence based guidelines for complex regional pain syndrome type 1

BackgroundTreatment of complex regional pain syndrome type I (CRPS-I) is subject to discussion. The purpose of this study was to develop multidisciplinary guidelines for treatment of CRPS-I.MethodA multidisciplinary task force graded literature evaluating treatment effects for CRPS-I according to their strength of evidence, published between 1980 to June 2005. Treatment recommendations based on the literature findings were formulated and formally approved by all Dutch professional associations involved in CRPS-I treatment.ResultsFor pain treatment, the WHO analgesic ladder is advised with the exception of strong opioids. For neuropathic pain, anticonvulsants and tricyclic antidepressants may be considered. For inflammatory symptoms, free-radical scavengers (dimethylsulphoxide or acetylcysteine) are advised. To promote peripheral blood flow, vasodilatory medication may be considered. Percutaneous sympathetic blockades may be used to increase blood flow in case vasodilatory medication has insufficient effect. To decrease functional limitations, standardised physiotherapy and occupational therapy are advised. To prevent the occurrence of CRPS-I after wrist fractures, vitamin C is recommended. Adequate perioperative analgesia, limitation of operating time, limited use of tourniquet, and use of regional anaesthetic techniques are recommended for secondary prevention of CRPS-I.ConclusionsBased on the literature identified and the extent of evidence found for therapeutic interventions for CRPS-I, we conclude that further research is needed into each of the therapeutic modalities discussed in the guidelines.

Diagnostic Validity of Criteria for Sacroiliac Joint Pain: A Systematic Review

UNLABELLED A systematic literature review was conducted to determine the diagnostic validity of the criteria for sacroiliac (SI) joint pain as proposed by the International Association for the Study of Pain (IASP). Databases were searched up to September 2007. Quality of the studies was assessed using a Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. Sensitivity, specificity, and diagnostic odds ratios (DOR) were calculated together with 95% confidence intervals (CI). Statistical pooling was conducted for results of provocative tests. Eighteen studies were included. Five studies examined the pattern of SI joint pain, whereas another 5 examined stressing test specific for SI joint pain. None of the studies evaluated the diagnostic validity of the SI joint infiltration or the diagnostic validity of the IASP criteria set as a whole. In all studies, the SI joint selective infiltration was used as a gold standard; however, the technique, medications, and required pain relief after the infiltration varied considerably between the studies. Taking the double infiltration technique as reference test, the pooled data of the thigh thrust test (DOR, 18.461; CI, 5.82 to 58.53), compression test (DOR, 3.88; CI, 1.7 to 8.9), and 3 or more positive stressing tests (DOR, 17.16; CI, 7.6 to 39) showed discriminative power for diagnosing SI joint pain. PERSPECTIVE This review of clinical studies focused on the diagnostic validity of the IASP criteria for diagnosing SI joint pain. A meta-analysis showed that the thigh thrust test, the compression test, and 3 or more positive stressing tests have discriminative power for diagnosing SI joint pain. Because a gold standard for SI joint pain diagnosis is lacking, the diagnostic validity of tests related to the IASP criteria for SI joint pain should be regarded with care.

Development of a severity score for CRPS

&NA; The clinical diagnosis of Complex Regional Pain Syndrome (CRPS) is a dichotomous (yes/no) categorization necessary for clinical decision‐making. However, such dichotomous diagnostic categories do not convey an individuals subtle and temporal gradations in severity of the condition, and have poor statistical power when used as an outcome measure in research. This study evaluated the validity and potential utility of a continuous type score to index severity of CRPS. Psychometric and medical evaluations were conducted in 114 CRPS patients and 41 non‐CRPS neuropathic pain patients. Based on the presence/absence of 17 clinically‐assessed signs and symptoms of CRPS, an overall CRPS Severity Score (CSS) was derived. The CSS discriminated well between CRPS and non‐CRPS patients (p < .001), and displayed strong associations with dichotomous CRPS diagnoses using both IASP diagnostic criteria (Eta = 0.69) and proposed revised criteria (Eta = 0.77–0.88). Higher CSS was associated with significantly higher clinical pain intensity, distress, and functional impairments, as well as greater bilateral temperature asymmetry and thermal perception abnormalities (p’s < .05). In an archival prospective dataset, increases in anxiety and depression from pre‐surgical baseline to 4 weeks post‐knee arthroplasty were found to predict significantly higher CSS at 6‐ and 12‐month follow‐up (p’s < .05). Results indicate the CSS corresponds with and complements currently accepted dichotomous diagnostic criteria for CRPS, and support its validity as an index of CRPS severity. Its utility as an outcome measure in research studies is also suggested, with potential statistical advantages over dichotomous diagnostic criteria.

Complex regional pain syndrome 1 - the Swiss cohort study

BackgroundLittle is known about the course of Complex Regional Pain Syndrome 1 and potential factors influencing the course of this disorder over time. The goal of this study is a) to set up a database with patients suffering from suspected CRPS 1 in an initial stadium, b) to perform investigations on epidemiology, diagnosis, prognosis, and socioeconomics within the database and c) to develop a prognostic risk assessment tool for patients with CRPS 1 taking into account symptomatology and specific therapies.Methods/designProspective cohort study. Patients suffering from a painful swelling of the hand or foot which appeared within 8 weeks after a trauma or a surgery and which cannot be explained by conditions that would otherwise account for the degree of pain and dysfunction will be included. In accordance with the recommendations of International Classification of Functioning, Disability and Health (ICF model), standardised and validated questionnaires will be used. Patients will be monitored over a period of 2 years at 6 scheduled visits (0 and 6 weeks, 3, 6, 12, and 24 months). Each visit involves a physical examination, registration of therapeutic interventions, and completion of the various study questionnaires. Outcomes involve changes in health status, quality of life and costs/utility.DiscussionThis paper describes the rationale and design of patients with CRPS 1. Ideally, potential risk factors may be identified at an early stage in order to initiate an early and adequate treatment in patients with increased risk for delayed recovery.Trial registrationNot applicable

Possible nociceptive structures in the sacroiliac joint cartilage: An immunohistochemical study.

The sacroiliac joint (SI joint) is a known source of low back pain. In the absence of validated physical signs and imaging studies, the diagnosis of SI joint pain can be secured by positive response to SI joint intra‐articular infiltration with local anesthetics. The current anatomical and histological knowledge concerning intra‐articular structures of the sacroiliac joint is insufficient to explain the efficacy of this infiltration. Consequently, this study was undertaken to detect the intra‐articular presence of substance P and calcitonin gene‐related peptide (CGRP) positive nerve fibers, providing indirect evidence of nociceptive innervation of the SI joint. Free‐floating sections, obtained from iliac and sacral cartilage and subchondral bone of the SI joint and adjacent ligamentous tissue, of 10 human cadavers were studied immunohistochemically. Tissue of nine human cadavers showed the presence of substance P and CGRP immunoreactivity in the superficial layer of sacral and iliac cartilage, and the surrounding ligamentous structures. Subchondral bone reacted weakly to the antisera used. These findings support the view that the SI joint may be capable of intra‐articular nociception and may explain the positive response to the intra‐articular deposition of local anesthetic. Clin. Anat. 23:192–198, 2010.

Treatment of Patients With Complex Regional Pain Syndrome Type I With Mannitol: A Prospective, Randomized, Placebo-Controlled, Double-Blinded Study

UNLABELLED To assess the effects of intravenous administration of the free radical scavenger mannitol 10% on complaints associated with complex regional pain syndrome Type I (CRPS I), a randomized, placebo-controlled, double-blinded trial was performed. Forty-one CRPS I patients according to the Bruehl et al diagnostic criteria, were included in 2 outpatient pain clinics of 2 university medical centers and randomly assigned to receive either 10% mannitol iv in 1 L 0.9% NaCL in 4 hours for 5 consecutive days or equal volumes of 0.9% NaCL (placebo). Patients in both groups received physical therapy according to protocol and rescue pain medication if required. Complaints on impairment and disability level and quality of life were assessed up to 9 weeks after baseline, with primary measurement points at 2, 6, and 9 weeks. Monitoring of pain using the visual analogue scale took place continuously during the course of the trial. Except for a significant improvement on a subscale of the Jebsen-Taylor hand function test, no significant differences were found between mannitol and placebo treatment. Changes in both groups in the course of the trial were small and clinically irrelevant on all measurement indices. We conclude that intravenous administration of 10% mannitol is not more effective than placebo in reducing complaints for CRPS I patients and provides no addition to already-established interventions for CRPS I. Whether 10% mannitol can provide beneficial effects for subgroups of CRPS I patients with a pathophysiological profile more closely fitting the presumed mode of action for this intervention remains to be established. PERSPECTIVE This article addresses the efficacy of the intravenous administration of the free radical scavenger mannitol for treatment of CRPS type 1. This intervention is not more effective than placebo in reducing complaints for CRPS I patients and provides no addition to already-established interventions for CRPS I.

Diagnostic criteria for CRPS I: differences between patient profiles using three different diagnostic sets.

Complex Regional Pain Syndrome type I (CRPS I) is an illness which usually occurs due to major or minor tissue injury to the extremities. Because a unique pathophysiological mechanism for CRPS I has not yet been established, the diagnosis is based on observation and measurement of clinical symptoms and signs. In this study, a comparison was made between three sets of diagnostic criteria (the IASP, Bruehl et al. and Veldman et al.) based on patient reports and physicians’ assessments of signs and symptoms associated with CRPS I, in 372 outpatients suspected of having CRPS I. Agreement between CRPS I diagnosis among the three sets was poor (κ‐range: 0.29–0.42), leading to positive CRPS I diagnoses according to Veldman et al.s criteria in 218 cases (59%), according to the IASP in 268 cases (72%), and according to Bruehl et al. in 129 cases (35%). Significant differences in patient profiles were found between the diagnostic sets for the number of patients reporting continuing disproportionate pain, larger area affected than the initial trauma (both p<0.001), increase of symptoms due to exercise (p=0.009), edema (p=0.015), temperature asymmetry (p=0.015), hyperesthesia, allodynia (both p<0.001) and hyperalgesia (p=0.036). Similarly, significant differences emerged for physicians’ observations of hyperesthesia and allodynia (both p<0.001). Highest combined values of sensitivity (SE) and specificity (SP) for the strongest cases of presence (n=108) or absence (n=62) of CRPS I were found for reported hyperesthesia (SE+SP:165%), allodynia (160%), observed color asymmetry (162%), hyperesthesia (157%), temperature asymmetry (154%) and edema (152%). The lack of agreement between the different diagnostic sets for CRPS I and the different clinical profiles that result from it may lead to different therapeutic and study populations, hampering adequate treatment and scientific development for this illness. We propose explicit reference to diagnostic criteria used in studies, and registration in trials of a broad variety of CRPS I features, as used in this study, to make subgroup phenotyping and post hoc analyses based on different diagnostic criteria possible.

Reliability of the Semmes Weinstein Monofilaments to measure coetaneous sensibility in the feet of healthy subjects.

Purpose. To determine the intrarater-reliability, interrater-reliability and normal reference scores of the Semmes Weinstein Monofilament test (SWM) of the feet of healthy subjects. In addition, the stability of the SWM for prospective use was assessed by determining systematic changes in sensory thresholds. Methods. Interrater-reliability was assessed on five locations of the plantar side of both feet using monofilaments 1.65, 2.36, 2.44, 2.83, 3.22, 3.61, 3.84, 4.08, 4.31, 5.56, 6.65 in 60 healthy subjects by two or three investigators (test day 1). Intrarater-reliability and systematic changes in sensory thresholds were assessed 3 weeks later (test day 22) by one investigator. Results. Median interrater-reliability for the five test locations for both feet was poor to moderate. Median intrarater-reliability was good for the left foot and poor to moderate for the right foot. Significantly lower median sensory thresholds were found for the first SWM measurement at test day 22 compared to the first and second measurement of test day 1. Given the observed reliability of the SWM, a normal sensory score for the feet was situated between monofilament 3.22 and 4.08. Conclusions. The SWM are reliable when measured by one researcher. Systematic changes in sensory thresholds were observed; therefore, the stability of the SWM for use in prospective studies could not be verified.

Spontaneous onset of Complex Regional Pain Syndrome

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.