Complex regional pain syndrome (CRPS), which used to be called reflex sympathetic dystrophy (RSD) is a puzzling illness for both doctors and patients. It’s a syndrome that doctors don’t understand as they don’t yet know what causes it. The syndrome causes intense pain that can be described as aching or burning. There can also be a change in skin color, the temperature of the skin over the affected area may feel different, and there may be sweating on just that area as well. Complex regional pain syndrome can occur after a minor injury, such as a pulled tendon or a bone break, but it can also happen after surgery, as well.
The doctors who see complex regional pain syndrome the most often are orthopedic surgeons and pain specialists, but the two groups don’t always diagnose the syndrome in the same way. Orthopedic surgeons usually see the syndrome in its early stages and still at a point when it may go away on its own. Therefore, the surgeons tend to treat complex regional pain syndrome with physiotherapy and pain relievers, ensuring that the affected joint keeps its normal movement. The pain specialists, however, see the syndrome when it has progressed far past the hopes that it may clear up on its own and it has likely not responded to any other treatments. Therefore, the specialist’s role is different than that of the surgeon’s role.
Although several studies have been done about diagnosis, there are differences between the retrospective studies, studies that look back and prospective studies, one that follow patients for a set amount of time. As well, here is a difference in the tools used to make the diagnosis. The authors of this study wanted to compare two methods of diagnosing complex regional pain syndrome to clarify the results of the earlier studies.
For the study, researchers looked at 262 patients who had fractured their radius, one of the lower arm bones, right next to the wrist. The group ranged in age from 17 to 93 years and was majority female (219 patients). All breaks were stabilized and casted; if the patient required surgery to repair the break, he or she wasn’t included in the study. As well, patients with any other arm injury were also excluded – the patients had to have just the wrist fracture.
After an average of nine weeks of when the patients first were seen (when the wrist was being set), the patients were assessed to see if they had any signs of complex regional pain syndrome, using two separate criteria. Their pain levels were assessed through testing and by asking the patients about the pain levels, and their hands were measured for temperature of the skin, how they perceived heat any swelling or muscle problems, and finger stiffness. According to one set of criteria, the Atkins Criteria, patients had to have an abnormal pain perception to heat in the fingers (dolorimetry), a high score (more than three out of 11) in measurement for blood flow in the hand, and abnormal joint stiffness.
For the second measurements, the Bruehl Criteria, the patients had to have abnormal pain and a symptom from each of the following four groups and an abnormal sign in two of the four groups: 1) abnormal sensations, 2) changes in the blood flow to the hand, 3) wasting away or muscle, difficulty moving the hand, and 4) swelling and sweating in the area.
When evaluating the findings, the researchers found that the number of cases of complex regional pain syndrome diagnosed were about the same using either criteria.: Bruehl criteria, 54 cases, and the Atkins criteria, 59 cases. There was disagreement between the two criteria in 19 cases, which seemed largely to be in assessing pain, blood flow, swelling, and joint stiffness. By the way the two criteria were measured, 12 patients who didn’t have any abnormal sensation to pain or heat had complex regional pain syndrome as measured by the Atkins criteria, but not by the Bruehl criteria. Four other patients who had normal dolorimetry measurements but abnormal sensations in their forearm had the syndrome if using the Bruehl criteria, but not if using the Atkins criteria. Yet another three patients were differently diagnosed because of their finger stiffness. They did have the syndrome if diagnosed with Bruehl criteria but not Atkins, although everything else in the Atkins criteria would have been acceptable.
Although there are several small differences in the two diagnostic criteria used by the doctors, the main difference appears to be how pain is perceived by the patient and the use of the finger to check for hypersensitivity. However, all else is very similar and lead to similar findings. The authors write that there were some limitations to their study, which may affect the outcome. The researchers did not use equipment to measure the temperature or color changes in the patients’ hands, but they pointed out that earlier studies have found that doctors are often able to do well by using their own assessment for these. The other drawback to the study is that only one doctor assessed the patients and didn’t have another opinion on the criteria measurements.
The authors concluded the article by stating that since there seemed to be little difference between the two criteria when diagnosing complex regional pain syndrome, they hope that this knowledge will allow the two main treating physicians to be able to work together more closely with their patients.