Complex regional pain syndrome (CRPS)-Type I is not yet well understood by the medical community. In fact, there are some who feel that it is not a neuropathic disorder at all, while others feel that it may be more common than thought. Regardless of the incidence, it's important that doctors recognize it as early as possible in order for the affected patients to receive proper treatment.
Up to now, there has only been one epidemiological study that looked in to who were the most likely people to develop CRPS and what might cause it. This month, a second such study was published that both contradicted and agreed with findings from the first study, published in 2002.
Some of the differences were most likely the result of the 2007 study being quite a bit larger than the 2002 study, 217,653 patients compared with 106,470 patients, respectively. The author of this editorial also points out that the 2007 study began following publication of official diagnostic criteria for CRPS, which could have affected the findings.
The 2007 study, using diagnosis from the patients' original treating physicians, found a higher incidence of patients with CRPS: 26.2 new cases per 100,000 people per year compared with the 2002 finding of 5.46 new cases per 100,000 people per year. When the 2007 study researchers looked at new cases that were diagnosed by specialists rather than by the original physicians, they still found a higher number of new cases than did the 2002 findings, at 16.8 new cases per 100,000 patients per year.
The researchers in the 2002 study used signs and symptoms that had been documented in the patients' records to diagnose 74 patients with CRPS. This study was done restrospectively, or looking back. The researchers in the 2007 study used signs and symptoms that were evaluated by pain specialists and that included specialized tests that weren't available to the researchers in the earlier study. The 2007 researchers found 95 patients with CRPS.
Because of the differing findings, the researchers from the second study have formally recommended that the criteria used to diagnose CRPS be reviewed.
The two studies did have some findings in common. Both noted that CRPS happened in significantly more women than men and among people between 50 and 70 years old. It was also found that CRPS seemed to be triggered after a patient had sustained a fracture or a sprain.
The author of this editorial concluded that, conservatively, it can be estimated that there may be 50,000 newly diagnosed cases of CRPS every year in the United States. By understanding who is at most risk of developing the disorder, doctors can be better prepared to diagnose and treat it, resulting in an improved quality of life for patients.
Stephen Bruehl, PhD. and Ok Yung Chung, MD. How common is complex regional pain syndrome-Type 1? In Pain. May 2007. Vol. 129. Issue 1-2. Pp. 1-2'