Epidemiology, Pathophysiology, and Management of Complex Regional Pain Syndrome

Complex Regional Pain Syndrome: Practical Diagnostic and Treatment Guidelines, 5th Edition

There have been some modest recent advancements in the research of Complex Regional Pain Syndrome, yet the amount and quality of the work in this complicated multifactorial disease remains low (with some notable exceptions; e.g., the recent work on the dorsal root ganglion stimulation). The semi-systematic (though in some cases narrative) approach to review is necessary so that we might treat our patients while waiting for "better research." This semi-systematic review was conducted by experts in the field, (deliberately) some of whom are promising young researchers supplemented by the experience of "elder statesman" researchers, who all mention the system they have used to examine the literature. What we found is generally low- to medium-quality research with small numbers of subjects; however, there are some recent exceptions to this. The primary reason for this paucity of research is the fact that this is a rare disease, and it is very difficult to acquire a sufficient sample size for statistical significance using traditional statistical approaches. Several larger trials have failed, probably due to using the broad general diagnostic criteria (the "Budapest" criteria) in a multifactorial/multi-mechanism disease. Responsive subsets can often be identified in these larger trials, but not sufficient to achieve statistically significant results in the general diagnostic grouping. This being the case the authors have necessarily included data from less compelling protocols, including trials such as case series and even in some instances case reports/empirical information. In the humanitarian spirit of treating our often desperate patients with this rare syndrome, without great evidence, we must take what data we can find (as in this work) and tailor a treatment regime for each patient.

Spinal cord stimulation as treatment for complex regional pain syndrome should be considered earlier than last resort therapy

BACKGROUND

Spinal cord stimulation (SCS), by virtue of its historically described up-front costs and level of invasiveness, has been relegated by several complex regional pain syndrome (CRPS) treatment algorithms to a therapy of last resort. Newer information regarding safety, cost, and efficacy leads us to believe that SCS for the treatment of CRPS should be implemented earlier in a treatment algorithm using a more comprehensive approach.

METHODS

We reviewed the literature on pain care algorithmic thinking and applied the safety, appropriateness, fiscal or cost neutrality, and efficacy (S.A.F.E.) principles to establish an appropriate position for SCS in an algorithm of pain care.

RESULTS AND CONCLUSION

Based on literature-contingent considerations of safety, efficacy, cost efficacy, and cost neutrality, we conclude that SCS should not be considered a therapy of last resort for CRPS but rather should be applied earlier (e.g., three months) as soon as more conservative therapies have failed.

Is there an association between psychological factors and the Complex Regional Pain Syndrome type 1 (CRPS1) in adults? A systematic review

Complex Regional Pain Syndrome type 1 (CRPS1) is a complication after trauma or surgery. Its pathophysiology is still a matter of debate, and psychological factors have been suggested to play a role, although their influence is unclear. The aim of this study was to investigate the evidence for the influence of psychological factors on the onset and maintenance of CRPS1 in adults. In a systematic review, articles were selected using Cochrane, Pubmed/Medline, Psychinfo, and Cinahl since 1980. Only original articles and empirical studies were included. Based on these selection criteria, 31 articles were identified. Studies were evaluated and weighted using a quality assessment instrument. The few prospective studies do not report a relationship between CRPS1 and depression, anxiety, neuroticism, or anger. The results of the retrospective/cross-sectional studies yield contradictory results regarding psychological problems in patients with CRPS1. A majority show no association, and studies with a higher methodological quality lean to a conclusion of no relationship between psychological factors and CRPS1. The majority of included studies (N=24; 77%) had only a poor to moderate methodological quality. Although many patients with CRPS1 are stigmatized as being psychologically different, this literature review identified no relationship between CRPS1 and several psychological factors. Only life events seemed to be associated with CRPS1: patients who experienced more life events appeared to have a greater chance of developing CRPS1. More studies with greater methodological quality and more participants should be performed on the association between psychological factors and the development and course of CRPS1.