Determination of inflammation of reflex sympathetic dystrophy at early stages with Tc-99m HIG scintigraphy: preliminary results

Poststroke Pain

Pain is common but often underrecognized after stroke. Poststroke pain (PSP) hinders recovery, impairs quality of life, and is associated with the psychological state of patients with stroke. The most common subtypes of PSP include central PSP, complex regional pain syndrome, shoulder pain, spasticity-related pain, and headache. The pathophysiologies of these PSP subtypes are not yet clearly understood, and PSP is refractory to conventional treatment in many patients. However, recent studies have proposed potential pathophysiologies of PSP subtypes, which may help prioritize therapies that target specific mechanisms.

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.

Bayesian meta-analysis of test accuracy in the absence of a perfect reference test applied to bone scintigraphy for the diagnosis of complex regional pain syndrome

There is conflicting evidence about the accuracy of bone scintigraphy (BS) for the diagnosis of complex regional pain syndrome 1 (CRPS 1). In a meta-analysis of diagnostic studies, the evaluation of test accuracy is impeded by the use of different imperfect reference tests. The aim of our study is to summarize sensitivity and specificity of BS for CRPS 1 and to identify factors to explain heterogeneity. We use a hierarchical Bayesian approach to model test accuracy and threshold, and we present different models accounting for the imperfect nature of the reference tests, and assuming conditional dependence between BS and the reference test results. Further, we include disease duration as explanatory variable in the model. The models are compared using summary ROC curves and the deviance information criterion (DIC). Our results show that those models which account for different imperfect reference tests with conditional dependence and inclusion of the covariate are the ones with the smallest DIC. The sensitivity of BS was 0.87 (95% credible interval 0.73-0.97) and the overall specificity was 0.87 (0.73-0.95) in the model with the smallest DIC, in which missing values of the covariate are imputed within the Bayesian framework. The estimated effect of duration of symptoms on the threshold parameter was 0.17 (-0.25 to 0.57). We demonstrate that the Bayesian models presented in this paper are useful to address typical problems occurring in meta-analysis of diagnostic studies, including conditional dependence between index test and reference test, as well as missing values in the study-specific covariates.

Complex regional pain syndrome type I: a comprehensive review

BACKGROUND

Complex regional pain syndrome type I (CRPS I), formerly known as reflex sympathetic dystrophy (RSD), is a chronic painful disorder that usually develops after a minor injury to a limb. This topical review gives a synopsis of CRPS I and discusses the current concepts of our understanding of CRPS I in adults, the diagnosis, and treatment options based on the limited evidence found in medical literature. CRPS I is a multifactorial disorder. Possible pathophysiological mechanisms of CRPS I are classic and neurogenic inflammation, and maladaptive neuroplasticity. At the level of the central nervous system, it has been suggested that an increased input from peripheral nociceptors alters the central processing mechanisms.

METHODS

A literature search was conducted using, as electronic bibliographic database, Medline from 1980 until 2014.

RESULTS

An early diagnosis and multidisciplinary treatment are necessary to prevent permanent disability.

CONCLUSIONS

The pharmacological treatment of CRPS I is empirical and insufficiently effective. Further research is needed regarding the therapeutic modalities discussed in the guidelines. Physical therapy is widely recommended as a first-line treatment. The efficacy of local anesthetic sympathetic blockade as treatment for CRPS I is questionable.

Post stroke pain: identification, assessment, and therapy

BACKGROUND

Pain is a common complication after stroke and is associated with the presence of depression, cognitive dysfunction, and impaired quality of life. It remains underdiagnosed and undertreated, despite evidence that effective treatment of pain may improve function and quality of life.

SUMMARY

We provide an overview of the means for clinical assessment and risk factors for the development of post-stroke pain, then review the newest available literature regarding the commonest post-stroke pain syndromes, including central post-stroke pain, complex regional pain syndrome, musculoskeletal pain including shoulder subluxation, spasticity-related pain, and post-stroke headache, as well as the available epidemiology and current treatment options. Key Messages: In the best interests of optimizing quality of life and function after stroke, clinicians should be aware of pain as a common complication after stroke, identify those patients at highest risk, directly inquire as to the presence and characteristics of pain, and should be aware of the options for treatment for the various pain syndromes.

Regulation of peripheral blood flow in complex regional pain syndrome: clinical implication for symptomatic relief and pain management

BACKGROUND

During the chronic stage of Complex Regional Pain Syndrome (CRPS), impaired microcirculation is related to increased vasoconstriction, tissue hypoxia, and metabolic tissue acidosis in the affected limb. Several mechanisms may be responsible for the ischemia and pain in chronic cold CPRS.

DISCUSSION

The diminished blood flow may be caused by either sympathetic dysfunction, hypersensitivity to circulating catecholamines, or endothelial dysfunction. The pain may be of neuropathic, inflammatory, nociceptive, or functional nature, or of mixed origin.

SUMMARY

The origin of the pain should be the basis of the symptomatic therapy. Since the difference in temperature between both hands fluctuates over time in cold CRPS, when in doubt, the clinician should prioritize the patient's report of a persistent cold extremity over clinical tests that show no difference. Future research should focus on developing easily applied methods for clinical use to differentiate between central and peripheral blood flow regulation disorders in individual patients.

Assessment of endothelial function in complex regional pain syndrome type I

The objective of this study is to investigate the endothelial function in complex regional pain syndrome. A total of 21 patients with CRPS and 15 healthy controls were enrolled. The mean age of patients was 22 +/- 4.9 years and the mean duration of the disease was 5.9 +/- 2.5 months. Flow-mediated vasodilatation (FMD) technique was performed for evaluating the endothelial function. Parameters were the waveforms obtained and the increase in diameter and blood flow of the brachial artery, which were expressed as the percent change from baseline. The differences of the waveforms obtained in the affected limbs in comparison to non-affected limbs and to controls were statistically significant. We observed a trend of greater percent dilating responses in the affected limbs; however, the differences showed no statistical significance. In macrovascular evaluation, the endothelial function seems to be impaired in the earlier stage of the disease.