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Reuters Thursday, November 15, 2001 By Melissa Schorr SAN FRANCISCO, Nov 15 (Reuters Health) - Brain scans have revealed that women with the chronic condition fibromyalgia differ from women with depression in their sensitivity to pain, researchers reported here Wednesday at the American College of Rheumatology's annual meeting. Fibromyalgia, a condition that affects 2% of Americans, usually women, causes muscle pain, stiffness and fatigue. The cause is unknown. Because nearly half of fibromyalgia patients have suffered clinical depression at some point in their lives, some doctors consider the condition to be a physical manifestation of an underlying mood disorder like depression, said Dr. Leanne R. Cianfrini, a psychology researcher at the University of Alabama at Birmingham. "Because fibromyalgia doesn't have a clear-cut etiology (or cause), it leads many rheumatologists to interpret their pain as a simple physical manifestation of an underlying depression," she said. "This can be frustrating and counterproductive to patients." To clarify whether there were physiological differences between patients with fibromyalgia and patients with depression, the investigators compared pain thresholds and brain activity among 21 women with fibromyalgia, 8 women with depression and 22 healthy women. Cianfrini and colleagues administered pressure calculated to be a level above each woman's pain threshold to three points on the women's bodies. The women were asked to evaluate their pain levels. The researchers also used a brain-imaging scan to measure each woman's brain blood flow while she experienced pain. The investigators found that the women with fibromyalgia had lower pain thresholds and reported more pain after pressure stimulation than the healthy women. The fibromyalgia patients also showed greater activation of brain structures that process pain after relatively low levels of pressure. The pain threshold and experience of pain among the depressed women was similar to that of the healthy women, the study found. "We can't deny depression is associated with fibromyalgia, and it may exacerbate it," Cianfrini said. "But depression does not seem to be a necessary factor." She advised fibromyalgia patients whose doctors seem resistant to treat them to tell them about her findings. "The pain is not due to depression and if they treat depression, your pain may not necessarily go away," she said. "Patients should say, 'Let's treat my pain, because it's real.'" In a similar study, Dr. Richard H. Gracely, a research psychologist at the National Institutes of Health, presented findings on how the brains of fibromyalgia patients react to pain. Gracely and colleagues used a brain scan technique called fMRI to compare fibromyalgia patients with healthy patients experiencing pain. The research team found that patients with fibromyalgia who were given relatively low levels of pressure seemed to experience the same amount of pain and subsequent brain activity as healthy people experiencing high levels of induced pain. "One of the big issues of pain patients is credibility--they don't have the luxury of physical signs, nobody believes they have what they say," Gracely said. "Fibromyalgia patients particularly had it that way because even rheumatologists didn't believe it was necessarily pain." However, these findings provide physical evidence to confirm what patients report, he added. "Brain imaging is a way to show there is something physical that matches with what they're saying," Gracely said. "It's welcome news to people who have this." Medline Plus Brain Scans Show Pain Sensitivity in Fibromyalgia artical & related links to FM & depression.  Functional magnetic resonance imaging evidence of augmented pain processing in fibromyalgia. Arthritis Rheum 2002 May;46(5):1333-43 Gracely RH, Petzke F, Wolf JM, Clauw DJ. National Institute of Dental and Craniofacial Research, NIH, Bethesda, Maryland, and Georgetown Chronic Pain and Fatigue Research Center, Georgetown University, Washington, DC. PMID: 12115241 Objective: To use functional magnetic resonance imaging (fMRI) to evaluate the pattern of cerebral activation during the application of painful pressure and determine whether this pattern is augmented in patients with fibromyalgia (FM) compared with controls. Methods: Pressure was applied to the left thumbnail beds of 16 right-handed patients with FM and 16 right-handed matched controls. Each FM patient underwent fMRI while moderately painful pressure was being applied. The functional activation patterns in FM patients were compared with those in controls, who were tested under 2 conditions: the "stimulus pressure control" condition, during which they received an amount of pressure similar to that delivered to patients, and the "subjective pain control" condition, during which the intensity of stimulation was increased to deliver a subjective level of pain similar to that experienced by patients. Results: Stimulation with adequate pressure to cause similar pain in both groups resulted in 19 regions of increased regional cerebral blood flow in healthy controls and 12 significant regions in patients. Increased fMRI signal occurred in 7 regions common to both groups, and decreased signal was observed in 1 common region. In contrast, stimulation of controls with the same amount of pressure that caused pain in patients resulted in only 2 regions of increased signal, neither of which coincided with a region of activation in patients. Statistical comparison of the patient and control groups receiving similar stimulus pressures revealed 13 regions of greater activation in the patient group. In contrast, similar stimulus pressures produced only 1 region of greater activation in the control group. Conclusion: The fact that comparable subjectively painful conditions resulted in activation patterns that were similar in patients and controls, whereas similar pressures resulted in no common regions of activation and greater effects in patients, supports the hypothesis that FM is characterized by cortical or subcortical augmentation of pain processing. Co-Cure  They did measure pain interpretation using pressure on the thumb nail using a "homemade gizmo" that applied various weights on the thumb nail in Phase 2 of the Twin Study. Preliminary thoughts is that the healthy twins is either less bothered by pain, tolerates it more or just "feels" less pain. This would lead to measuring substance P during this test, measuring attitudes & expectations towards pain. (Idea for Phase 3). I'm the "healthy twin" who rated the highest pain tolerance out of 7 sets of twins & even the researchers who "played" with the gizmo. Murphy's Law: If something can go wrong it will. The gizmo couldn't handle all the weight.  University of Michigan Date: June 7, 2002 URL: http://www.bioresearchonline.com/content/news/article.asp?docid={B88E912B-7896-11D6-A789-00D0B7694F32}&VNETCOOKIE=NO http://www.sciencedaily.com/releases/2002/06/020607073056.htm Fibromyalgia pain isn't all in patients' heads, new brain study finds fMRI scans give first objective measure of mysterious ailment, provide road map for future study ANN ARBOR, MI - A new brain-scan study confirms scientifically what fibromyalgia patients have been telling a skeptical medical community for years: They're really in pain. In fact, the study finds, people with fibromyalgia say they feel severe pain, and have measurable pain signals in their brains, from a gentle finger squeeze that barely feels unpleasant to people without the disease. The squeeze's force must be doubled to cause healthy people to feel the same level of pain - and their pain signals show up in different brain areas. The results, published in the current issue of Arthritis & Rheumatism, the journal of the American College of Rheumatology, may offer the proof of fibromyalgia's physical roots that many doubtful physicians have sought. It may also open doors for further research on the still-unknown causes of the disease, which affects more than 2 percent of Americans, mainly women. Lead authors Richard Gracely, Ph.D., and Daniel Clauw, M.D., did the study at Georgetown University Medical Center and the National Institutes of Health, but are now continuing the work at the University of Michigan Health System. In an editorial in the same issue, Clauw and U-M rheumatologist Leslie Crofford, M.D., stress the importance of fibromyalgia research and care. To correlate subjective pain sensation with objective views of brain signals, the researchers used a super-fast form of MRI brain imaging, called functional MRI or fMRI, on 16 fibromyalgia patients and 16 people without the disease. As a result, they say, the study offers the first objective method for corroborating what fibromyalgia patients report they feel, and what's going on in their brains at the precise moment they feel it. And, it gives researchers a road map of the areas of the brain that are most - and least - active when patients feel pain. "The fMRI technology gave us a unique opportunity to look at the neurobiology underlying tenderness, which is a hallmark of fibromyalgia," says Clauw. "These results, combined with other work done by our group and others, have convinced us that some pathologic process is making these patients more sensitive. For some reason, still unknown, there's a neurobiological amplification of their pain signals." Further results from the study were presented last year at the ACR annual meeting. The project will continue later this year at UMHS, joining other fMRI fibromyalgia research now under way. For decades, patients and physicians have built a case that fibromyalgia is a specific, diagnosable chronic disease, characterized by tenderness and stiffness all over the body as well as fatigue, headaches, gastrointestinal problems and depression. Many patients with the disease find it interferes with their work, family and personal life. Statistics show that far more women than men are affected, and that it occurs mostly during the childbearing years. The ACR released classification criteria for fibromyalgia in 1990, to help doctors diagnose it and rule out other chronic pain conditions. Clauw and Crofford's editorial looks at the current state of research, and calls for rheumatologists to take the lead in fibromyalgia care and science. But many skeptics have debated the very existence of fibromyalgia as a clearly distinct disorder, saying it seemed to be rooted more in psychological and social factors than in physical, biological causes. Their argument has been bolstered by the failure of research to find a clear cause, an effective treatment, or a non-subjective way of assessing patients. While the debate has raged, neuroscientists have begun to use brain scan technology to identify the areas of the normal human brain that become most active during pain. A few studies have even assessed the blood flow in those areas in fibromyalgia patients during baseline brain scans. The new study is the first to use both high-speed scanning and a painful stimulus. In the study, fibromyalgia patients and healthy control subjects had their brains scanned for more than 10 minutes while a small, piston-controlled device applied precisely calibrated, rapidly pulsing pressure to the base of their left thumbnail. The pressures were varied over time, using painful and non-painful levels that had been set for each patient prior to the scan. The study's design gave two opportunities to compare patients and controls: the pressure levels at which the pain rating given by patients and control subjects was the same, and the rating that the two different types of participants gave when the same level of pressure was applied. The researchers found that it only took a mild pressure to produce self-reported feelings of pain in the fibromyalgia patients, while the control subjects tolerated the same pressure with little pain. "In the patients, that same mild pressure also produced measurable brain responses in areas that process the sensation of pain," says Clauw. "But the same kind of brain responses weren't seen in control subjects until the pressure on their thumb was more than doubled." Though brain activity increased in many of the same areas in both patients and control subjects, there were striking differences too. Patients feeling pain from mild pressure had increased activity in 12 areas of their brains, while the control subjects feeling the same pressure had activation in only two areas. When the pressure on the control subjects' thumbs was increased, so did their pain rating and the number of brain areas activated. But only eight of the areas were the same as those in patients' brains. In all, the fibromyalgia patients' brains had both some areas that were activated in them but not in controls, and some areas that stayed "quiet" in them but became active in the brains of controls feeling the same level of pain. This response suggests that patients have enhanced response to pain in some brain regions, and a diminished response in others, Clauw says. The study was supported in part by the National Fibromyalgia Research Association, the U.S. Army and the NIH. In addition to Clauw and Gracely, the research team included Frank Petzke, M.D.; and Julie M. Wolf, BA. For more information on fibromyalgia research at UMHS, visit http://www.med.umich.edu/intmed/rheumatology/fmweb. Source: U-M Health System Public Relations  Co-Cure |