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In Pain May 2007. Vol. 129. Issue 1-2. Pp. 12-20

Complex regional pain syndrome (CRPS) is a painful disorder that is not yet well understood by the medical community. In the past, CRPS has also been called Sudecks dystrophy and reflex sympathetic dystrophy. Because there are many symptoms to CRPS, patients aren't treated by any one specialty of doctors, and different patients may be seen by different specialists, like anesthesiologists, orthopedic surgeons, neurologists, rheumatologists, general physicians, and rehabilitation specialists. These doctors all bring different backgrounds and approaches to the disorder.

This study was retrospective, or looking back, and the researchers identified cases that were then verified by information provided by both treating specialists and general physicians. The researchers' aim was to determine how many people were afflicted with CRPS and which populations were more likely to develop it. A study done a few years earlier was also done retrospectively, but with the file records alone.

In this study, the records of 217,653 patients were examined and 238 patients were identified as having CRPS; 177 were diagnosed by specialists and the specialists most often involved in care were anesthesiologists.

The researchers found that most of the patients had sustained either a fracture (most common) or a sprain (second most common) before the onset of CRPS. Other trauma, like surgery, had occurred in a few people, but in 10 percent of the cases, there were no apparent traumas. Women were affected almost three times more often than were men and more patients were in the 61 to 70 year old age group. This is also the postmenopausal period for women.

Four times more people in this study were found to have CRPS than were found in the earlier study that was published in 2002. And, even though the number was higher in the second study, the researchers said that their incidence rates may still be an underestimation of the true number.

The researchers concluded that there would be 26.2 new cases of CRPS per 100,000 people per year and it would be better if there were more uniform and consistent criteria on which to base a diagnosis.

1. Introduction

Complex regional pain syndrome (CRPS), formerly known as Sudecks dystrophy or reflex sympathetic dystrophy, is a painful disease with clinical features that include pain, sensory, sudo- and vasomotor disturbances, trophic changes and impaired motor function (Bruehl et al., 2002). The disease course varies from relatively mild and self-limiting to chronic disease with a high impact on daily functioning and quality of life (Galer et al., 2000). Usually, symptoms appear in one extremity after even a relatively mild trauma, for example a fracture, contusion or surgery, but symptoms have also been described after varicella zoster infection and myocardial infarction (Merritt, 2005). The diagnosis is based on the findings during the history and physical examination, for which several diagnostic criteria sets have been developed. The most well known are the IASP (International Association for the Study of Pain) criteria, that were established during a consensus meeting of experts in 1994 (Stanton-Hicks et al., 1995). The pathogenesis and etiology may involve both neurological and inflammatory disorders, but remain to be completely unraveled (Janig and Baron, 2004, Birklein, 2005).

Due to its complexity and broad spectrum of symptoms, CRPS patients are treated by physicians from different clinical backgrounds, including anesthesiologists, (orthopedic) surgeons, neurologists, rheumatologists and rehabilitation doctors. The incidence of CRPS has been studied retrospectively and prospectively in clinical settings after a certain precipitating event, most frequently after a distal radius fracture (Atkins et al., 1990, Veldman et al., 1993, Field and Atkins, 1997, Zollinger et al., 1999, Dijkstra et al., 2003). Sandroni and colleagues have been the only ones so far to assess the incidence of CRPS in the general population (Olmsted County, USA) and they reported an incidence rate of 5.46/100,000 person years (Sandroni et al., 2003).

In our study, the objective was to assess the incidence of CRPS in the general population in the Netherlands. Moreover, we classified cases according to different diagnostic criteria and described the precipitating events of CRPS.

M. de Mos, et al. The incidence of complex regional pain syndrome: A population-based study. In Pain. May 2007. Vol. 129. Issue 1-2. Pp. 12-20.

If you would like to see the study in its entirety please click on the link below;

The incidence of complex regional pain syndrome: A population-based study