Synovial effusion in reflex sympathetic dystrophy: an additional sign for diagnosis and staging

Modern Principles of Diagnosis and Treatment in Complex Regional Pain Syndrome

BACKGROUND

Background: Complex regional pain syndrome (CRPS) is a relatively common complication, occurring in 5% of cases after injury or surgery, particularly in the limbs. The incidence of CPRS is around 5-26/100 000. The latest revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-11) now categorizes CRPS as a primary pain condition of multifactorial origin, rather than a disease of the skeletal system or the autonomic nervous system.

METHODS

Method: Based on a selective search of the literature, we summarize current principles for the diagnosis and treatment of CRPS.

RESULTS

Results: Regional findings in CRPS are accompanied by systemic symptoms, especially by neurocognitive disorders of body perception and of symptom processing. The therapeutic focus is shifting from predominantly passive peripheral measures to early active treatments acting both centrally and peripherally. The treatment is centered on physiotherapy and occupational therapy to improve sensory perception, strength, (fine) motor skills, and sensorimotor integration/ body perception. This is supported by stepped psychological interventions to reduce anxiety and avoidance behavior, medication to decrease inflammation and pain, passive physical measures for reduction of edema and of pain, and medical aids to improve functioning in daily life. Interventional procedures should be limited to exceptional cases and only be performed in specialized centers. Spinal cord and dorsal root ganglion stimulation, respectively, are the interventions with the best evidence.

CONCLUSION

Conclusion: The modern principles for the diagnosis and treatment of CRPS consider both, physiological and psychological mechanisms, with the primary goal of restoring function and participation. More research is needed to strengthen the evidence base in this field.

Neurovascular, muscle, and skin changes on [18F]FDG PET/MRI in complex regional pain syndrome of the foot: A Prospective Clinical Study

Objective

The goal of this study is to demonstrate the feasibility of simultaneous [¹⁸F]-fluorodeoxyglucose (FDG) positron emission tomography (PET) and magnetic resonance imaging (MRI) for noninvasive visualization of muscular, neurovascular, and skin changes secondary to complex regional pain syndrome (CRPS).

Subjects

Seven adult patients with CRPS of the foot and seven healthy adult controls participated in our [¹⁸F]FDG PET/MRI study.

Methods

All participants received whole-body PET/MRI scans 1 hour after the injection of 370MBq [¹⁸F]FDG. Resulting PET/MRI images were reviewed by two radiologists. Metabolic and anatomic abnormalities identified, were grouped into muscular, neurovascular, and skin lesions. The [¹⁸F]FDG uptake of each lesion was compared with that of corresponding areas in controls using a Mann-Whitney U-test.

Results

On PET images, muscular abnormalities were found in five patients, neurovascular abnormalities in four patients, and skin abnormalities in two patients. However, on MRI images, no muscular abnormalities were detected. Neurovascular abnormalities and skin abnormalities in the affected limb were identified on MRI in one and two patients, respectively. The difference in [¹⁸F]FDG uptake between the patients and the controls was significant in muscle (P = .018) and neurovascular bundle (P = .0005).

Conclusions

The increased uptake of [¹⁸F]FDG in the symptomatic areas likely reflects the increased metabolism due to the inflammatory response causing pain. Therefore, our approach combining metabolic [¹⁸F]FDG PET and anatomic MR imaging may offer noninvasive monitoring of the distribution and progression of inflammatory changes associated with CRPS.

MRI of complex regional pain syndrome in the foot

PURPOSE

To evaluate the diagnostic potential of MRI in patients with suspected CRPS (complex regional pain syndrome).

METHOD

A retrospective health-record search was conducted for patients with suspected CRPS (foot). Fifty patients with initially suspected CRPS were included (37 females (51 ± 13 years) and 13 males (44 ± 15 years)). All patients underwent MRI. Two radiologists assessed skin, bone, and soft tissue parameters on MRI. The final diagnosis was CRPS (Gold standard: Budapest criteria) or non-CRPS. MRI parameters were compared between CRPS patients and non-CRPS patients.

RESULTS

CRPS was diagnosed in 22/50(44 %) patients. Skin thickness (1.9 ± 0.5 mm vs. 1.7 ± 0.3 mm, p = 0.399), enhancement, and subcutaneous edema showed no differences between CRPS and non-CRPS patients. Bone marrow edema presence and pattern were not different between groups. Up to 50 % of CRPS patients showed no bone marrow edema. Subcortical enhancement and periosteal enhancement were not different between groups. For reader 1, muscle edema score was higher in the non-CRPS group compared to the CRPS group (0.1 ± 0.2 vs. 0.6 ± 1.0, p = 0.008), but not different for reader 2 (0.1 ± 0.5 vs. 0.2 ± 0.8, p = 0.819). Perfusion pattern was more extensive in non-CRPS patients for reader 1 (p = 0.048), but not for reader 2 (p = 0.157). Joint effusions showed no difference between groups.

CONCLUSIONS

MRI cannot distinguish between CRPS and non-CRPS patients. The role of MR imaging in patients with suspected CRPS is to exclude alternative diagnoses that would better explain patients' symptoms.

Adult Complex Regional Pain Syndrome Type I: A Narrative Review

Complex regional pain syndrome type I (CRPS I) is a multifactorial painful disorder with a complex pathogenesis. Both peripheral and central mechanisms are involved. Acute CRPS I is considered to be an exaggerated inflammatory disorder; however, over time, because of altered function of the sympathetic nervous system and maladaptive neuroplasticity, CRPS I evolves into a neurological disorder. This review thoroughly describes the pathophysiological aspects of CRPS I and summarizes the potential therapeutic options. The mechanisms and targets of the treatment are different in the early and late stages of the disease. This current review builds on a previous review by this author group by deepening the role of the peripheral classic and neuronal inflammatory component in the acute stage of this painful disorder.

LEVEL OF EVIDENCE

Not applicable.

Case report: imaging features in a renal transplant patient with calcineurin inhibitor-induced pain syndrome (CIPS)

Post-transplant distal limb bone marrow edema syndrome or calcineurin inhibitor-induced pain syndrome (CIPS) is generally a self-limiting but debilitating acute pain syndrome that has been reported in 2-14 % of renal transplant recipients. The disease is extensively described in the transplant literature in patients receiving the calcineurin inhibitors cyclosporine and tacrolimus. We present a case of CIPS arising in a patient 73 days after renal allograft, review the imaging findings, and discuss proposed etiologies and differential diagnoses. To the authors' knowledge, CIPS has not been characterized as a distinct entity in the radiology literature.

SPECT/CT versus MRI in patients with nonspecific pain of the hand and wrist - a pilot study

BACKGROUND

Hand and wrist pain is a diagnostic challenge for hand surgeons and radiologists due to the complex anatomy of the involved small structures. The American College of Radiology recommends MRI as the study of choice in patients with chronic wrist pain if radiographs are negative. Lately, state-of-the-art SPECT/CT systems have been introduced and may help in the diagnosis of this selected indication.

MATERIALS AND METHODS

This retrospective study included 21 patients with nonspecific pain of the hand/wrist. The diagnosis of nonspecific wrist pain was made by the referring hand surgeon based on patient history, clinical examination, plain radiography and clinical guidelines. All patients received planar early-phase imaging and late-phase SPECT/CT imaging as well as MRI. Lesions were divided into major (causative) and minor (not causative) pathologies according to clinical follow-up. Furthermore, oedema-like bone marrow changes seen on MRI were compared with focally increased tracer uptake seen on SPECT/CT images.

RESULTS

MRI yielded a quite high sensitivity (0.86), but a low specificity (0.20). In contrast, SPECT/CT yielded a high specificity (1.00) and a low sensitivity (0.71). Oedema-like bone marrow changes were detected in 15 lesions in 11 patients. In ten lesions with bone marrow oedema on MRI, foci of elevated tracer uptake were detected on SPECT/CT. Overall, MRI was more sensitive, but SPECT/CT was more specific in the evaluation of causative pathologies.

CONCLUSION

In this initial comparison, SPECT/CT showed higher specificity than MRI in the evaluation of causative pathologies in patients with nonspecific wrist pain. However, MRI was more sensitive. Thus, SPECT/CT was shown to be a useful problem-solving tool in the diagnostic work-up of these patients.

Behavioral and sensory changes after direct ischemia-reperfusion injury in rats

Complex regional pain syndromes (CRPS) are disabling pain syndromes that can develop after trauma or minor tissue injury affecting a limb. Characteristics of CRPS are sensory signs and symptoms, autonomic abnormalities, trophic changes and an impaired motor function. Pathophysiological mechanisms for the development of CRPS are still a matter of investigation. Based on clinical data and investigations of CRPS patients it is hypothesized that tissue hypoxia and inflammation are important for the development of CRPS. The aim of the current study was therefore to examine if direct ischemia-reperfusion injury can induce behavior in rats with symptoms present in patients with CRPS. After baseline behavior measurements the femoral artery of Wistar rats was ligated for 3h with consecutive reperfusion. Sham-operated rats underwent the same preparation except ligation of the artery. Subsequent behavioral testing (observations of spontaneous pain behavior, paw withdrawal to mechanical, noxious mechanical, cold and heat stimuli) was performed up to two months after surgery. Both in rats that underwent ischemia and in sham-operated rats no obvious changes of hindpaw tissue were observed after ischemia-reperfusion injury (trophic changes, edema, differences in skin color or temperature). In behavioral tests only minor changes were observed, these being not different between postischemic rats and sham-operated rats. Using Wistar rats, our data do not support the idea that an ischemia-reperfusion injury can play a major role in the development of CRPS.

Still's Disease and Recurrent Complex Regional Pain Syndrome Type-I: The First Description

Complex regional pain syndrome (CRPS) is a chronic neuropathic pain disorder characterized by neuropathic pain associated with local edema and changes suggestive of autonomic involvement such as altered sweating, skin color, and skin temperature of the affected region. CRPS was described associated with several diseases, such as trauma, psychiatric conditions, and cancer. However, no case associated with Still's disease has been previously described. In this paper, the authors describe the first case of CRPS associated with Still's disease.

Optimization of a double inversion recovery sequence for noninvasive synovium imaging of joint effusion in the knee

PURPOSE

We wanted to optimize a double inversion recovery (DIR) sequence to image joint effusion regions of the knee, especially intracapsular or intrasynovial imaging in the suprapatellar bursa and patellofemoral joint space.

METHODS

Computer simulations were performed to determine the optimum inversion times (TI) for suppressing both fat and water signals, and a DIR sequence was optimized based on the simulations for distinguishing synovitis from fluid. In vivo studies were also performed on individuals who showed joint effusion on routine knee MR images to demonstrate the feasibility of using the DIR sequence with a 3T whole-body MR scanner. To compare intracapsular or intrasynovial signals on the DIR images, intermediate density-weighted images and/or post-enhanced T1-weighted images were acquired.

RESULTS

The timings to enhance the synovial contrast from the fluid components were TI1 = 2830 ms and TI2 = 254 ms for suppressing the water and fat signals, respectively. Improved contrast for the intrasynovial area in the knees was observed with the DIR turbo spin-echo pulse sequence compared to the intermediate density-weighted sequence.

CONCLUSIONS

Imaging contrast obtained noninvasively with the DIR sequence was similar to that of the post-enhanced T1-weighted sequence. The DIR sequence may be useful for delineating synovium without using contrast materials.

Complex regional pain syndrome type I: neuropathic or not?

Complex regional pain syndrome (CRPS) is clinically characterized by pain, abnormal regulation of blood flow and sweating, edema of skin and subcutaneous tissues, active and passive movement disorders, and trophic changes. It is classified as type I (reflex sympathetic dystrophy) and type II (causalgia). CRPS cannot be reduced to one system or to one mechanism only. In the past decades, there has been absolutely no doubt that complex regional pain syndromes have to be classified as neuropathic pain disorders. This situation changed when a proposal to redefine neuropathic pain states was recently published, which resulted in an exclusion of CRPS from neuropathic pain disorders. We analyzed the strength of the scientific evidence that supports the neuropathic nature of complex regional pain syndromes.

Imaging in Early Posttraumatic Complex Regional Pain Syndrome

OBJECTIVES

The complex regional pain syndrome type I (CRPS I) still is difficult to diagnose in posttraumatic patients. As CRPS I is a clinical diagnosis the characteristic symptoms have to be differentiated from normal posttraumatic states. Several diagnostic procedures are applied to facilitate an early diagnosis, although their value for diagnosing posttraumatic CRPS I is unclear.

METHODS

One hundred fifty-eight consecutive patients with distal radial fracture were followed up for 16 weeks after trauma. To assess the diagnostic value of the commonly applied methods a detailed clinical examination was carried out 2, 8, and 16 weeks after trauma in conjunction with bilateral thermography, plain radiographs of the hand skeleton, three phase bone scans (TPBSs), and contrast-enhanced magnetic resonance imaging (MRI). All imaging procedures were assessed blinded.

RESULTS

At the end of the observation period 18 patients (11%) were clinically identified as having CRPS I and 13 patients (8%) revealed an incomplete clinical picture which were defined as CRPS borderline cases. The sensitivity of all diagnostic procedures used was poor and decreased between the first and the last examinations (thermography: 45% to 29%; TPBS: 19% to 14%; MRI: 43% to 13%; bilateral radiographs: 36%). In contrast a high specificity was observed in the TPBS and MRI at the eighth and sixteenth-week examinations (TPBS: 96%, 100%; MRI: 78%, 98%) and for bilateral radiographs 8 weeks after trauma (94%). The thermography presented a fair specificity that improved from the second to the sixteenth week (50% to 89%).

DISCUSSION

The poor sensitivity of all tested procedures combined with a reasonable specificity produced a low positive predictive value (17% to 60%) and a moderate negative predictive value (79% to 86%). These results suggest, that those procedures cannot be used as screening tests. Imaging methods are not able to reliably differentiate between normal posttraumatic changes and changes due to CRPS I. Clinical findings remain the gold standard for the diagnosis of CRPS I and the procedures described above may serve as additional tools to establish the diagnosis in doubtful cases.

MR imaging of epiphyseal lesions of the knee: current concepts, challenges, and controversies

This article focuses on spontaneous painful conditions involving the subchondral bone and marrow of mature knee epiphyses. MR imaging is the technique of choice for the work-up of these lesions and enables distinction of two main categories of lesions on the basis of T1-weighted images: avascular necrosis, and lesions presenting the bone marrow edema pattern. This latter category encompasses spontaneous osteonecrosis of the knee, and a variety of self-resolving conditions that may be differentiated by the study of the subchondral bone marrow area on T2-weighted images. Behind definite appellation of lesions, the challenge for the radiologist is to provide a prognosis: the distinction between self-resolving lesions from those that may evolve to epiphyseal collapse and joint impairment should be possible in most cases.

Complex regional pain syndrome--diagnostic, mechanisms, CNS involvement and therapy

Complex regional pain syndromes (CRPS, formerly reflex sympathetic dystrophy and causalgia) are neuropathic pain conditions of one extremity developing inadequately after a trauma. The initiating trauma affects primarily the extremity, but can also be a central lesion (e.g., spinal cord injury, stroke). CRPS is clinically characterized by sensory, autonomic and motor disturbances. Pathophysiologically there is evidence for functional changes within the central nervous system and for involvement of peripheral inflammatory processes. The sympathetic nervous system plays a key role in maintaining pain and autonomic dysfunction in the affected extremity. After a primary central lesion, secondary peripheral changes in the paretic extremity are suggested to be important in initiating a CRPS. Though there is no diagnostic gold standard, careful clinical evaluation and additional test procedures should lead to an adequate diagnosis. An early diagnosis and an interdisciplinary approach are important for optimal and successful treatment.

A clinical report of the effect of mechanical stress on functional results after fasciectomy for Dupuytren's contracture

Early postoperative treatment after Dupuytren's fasciectomy traditionally has included the application of mechanical stress to digital extension with splints and exercise. This study examines the effect of mechanical stress, which may compromise nutrient delivery to the tissues, on inflammation, flare, hypertrophic scar, digital range of motion (ROM), and therapy visits. The authors compared functional outcomes in operated digits treated postoperatively with tension applied (TA) and no tension applied (NTA), retrospectively from 1983 to 1993 (TA only) and prospectively from 1993 to 1999 (TA and NTA). The charts of 268 patients who underwent Dupuytren's fasciectomy were reviewed and divided into 2 groups (TA and NTA). Each case was analyzed with respect to age, sex, number of digits operated, postoperative management technique, therapy visits, metacarpophalangeal joint and proximal interphalangeal joint ROM, degree of flare, and scar. There were significant differences in ROM, scar formation, flare, and treatment time in favor of the NTA technique. The results indicate that postoperative management that prevents applied mechanical tension in the early phases of wound healing decreases complications after this surgery and that no digital motion is lost to extension with the NTA technique.

The knee: bone marrow abnormalities

MRI is clearly the imaging modality of choice for detecting and exploring joint, osseous, and soft tissue injuries in the lower extremity and throughout the musculoskeletal system. Its ability to detect and differentiate the various forms of marrow pathology is unrivaled, and as such it should be obtained early in the work-up of a patient with a suspected marrow abnormality. Additionally, the radiologist must be familiar with the MRI appearances of normal marrow and the most common types of marrow pathology if its diagnostic power is to be fully realized.

Complex regional pain syndrome type I: use of the International Association for the Study of Pain diagnostic criteria defined in 1994

OBJECTIVES

The objective was to assess the reported use in recent publications of the diagnostic criteria for complex regional pain syndrome type I (CRPS I) proposed by the International Association for the Study of Pain (IASP) in 1994.

METHODS

A literature search of MEDLINE (January 1996 to July 2000) was performed with use of the medical subject heading "reflex sympathetic dystrophy" and the free texts words "complex," "regional," "pain," and "syndrome." Publications in English, German, and Dutch were analyzed. From the search, 65 original publications were selected. Another 27 publications (referenced publications) that were referenced in the 65 original publications for the description of diagnostic criteria for CRPS I also were included. A standard form was used to assess a total of 92 publications. A sensitivity analysis was performed by means of analyzing three scenarios in which the diagnostic criteria were used as proposed and two combinations of less stringent criteria.

RESULTS

Use of the diagnostic criterion pain was reported in 35 (38%) of the analyzed publications. None of the original publications satisfied the proposed IASP diagnostic criteria. Four (15%) of the referenced publications satisfied the proposed IASP diagnostic criteria. Ten (15%) of the original publications referred correctly to the referenced publications. With the less strict criteria used in scenarios 2 and 3, 2 (3%) and 3 (5%), respectively, of the original publications fulfilled these criteria.

CONCLUSIONS

If the diagnostic criteria for CRPS I are not used uniformly, the populations in clinical studies may not be uniform either. Whether different authors are describing the same syndrome and whether their findings can be compared is open to question. On the basis of the results of this study, it is concluded that the IASP criteria for CRPS I are poorly used in clinical studies.

Controversies surrounding reflex sympathetic dystrophy: a review article

The topic of reflex sympathetic dystrophy (RSD) has generated an increasingly significant volume of medical literature and controversy over the last decade. A search of PubMed, the online site of the National Library of Medicine, for papers on RSD reveals nearly 2200 articles on the topic (using algodystrophy as the search word, wherein RSD references are also included, and more older and European articles are also listed). From 1991 through 1998 inclusive there is an average of nearly 100 articles per year on the topic, which represents more than a third of all the articles referenced since 1965. In the decade of the 1980s, there is an average of 64 articles per year, 74 per year in the last half of the decade and 54 per year in the first half. Prior to the decade of the 1980s, one finds an average of 40 articles per year back to the mid-1960s. The controversy surrounding the disorder centers around the nature of the problem and whether it is a primary organic disorder or a primary psychogenic disorder associated with the accomplishment of some secondary gain. If it is the former, then clearly research should continue to determine the nature and etiology of the malfunctioning organ(s). If, on the other hand, RSD is a psychogenic disorder, then the medical community does well to focus mainly on the peripheral manifestations of the problem. In that instance, therapy should be primarily psychological and cognitive with regard to the secondary gain, and persistent organic treatments are unlikely to improve the condition in general and worsen individual cases.

Algodystrophy

Algodystrophy is a clinical syndrome characterized by intense locoregional pain, vasomotor and trophic changes and delayed recovery, mostly occurring after trauma or surgery. The variety of nomenclature reflects the spectrum of clinical presentations and the uncertain pathophysiology. Although most patients recover, it can result in persistent disability in some patients. The diagnosis is based mostly on clinical signs. The specificity and sensitivity of additional technical investigations, such as radionuclide scintigraphy and X-ray, is variable. Algodystrophy progresses in several stages, from an inflammation-like clinical picture to recovery or sequels. The management is mainly supportive and can be difficult in some patients, especially in persistent chronic cases or when recognized at a late stage. Management is based on the results of limited prospective controlled studies. There is a need for a better understanding of the pathophysiology and for prospective clinical studies about the natural course and the effect of treatment.