The amount of blood flowing in two areas of the brain differs in people who feel musculoskeletal pain characteristic of fibromyalgia. So even though the sufferers of this disorder feel pain in their muscles and bones the actual pain might be originating in the brain.
Reston, Va.—Using single photon emission computed tomography (SPECT), researchers in France were able to detect functional abnormalities in certain regions in the brains of patients diagnosed with fibromyalgia, reinforcing the idea that symptoms of the disorder are related to a dysfunction in those parts of the brain where pain is processed.
"Fibromyalgia is frequently considered an 'invisible syndrome' since musculoskeletal imaging is negative," said Eric Guedj, M.D., and lead author of the study. "Past imaging studies of patients with the syndrome, however, have shown above-normal cerebral blood flow (brain perfusion) in some areas of the brain and below-normal in other areas. After performing whole-brain scans on the participants, we used a statistical analysis to study the relationship between functional activity in even the smallest area of the brain and various parameters related to pain, disability and anxiety/depression."
In the study, which was reported in the November issue of The Journal of Nuclear Medicine, 20 women diagnosed with fibromyalgia and 10 healthy women as a control group responded to questionnaires to determine levels of pain, disability, anxiety and depression. SPECT was then performed, and positive and negative correlations were determined.
The researchers confirmed that patients with the syndrome exhibited brain perfusion abnormalities in comparison to the healthy subjects. Further, these abnormalities were found to be directly correlated with the severity of the disease. An increase in perfusion (hyperperfusion) was found in that region of the brain known to discriminate pain intensity, and a decrease (hypoperfusion) was found within those areas thought to be involved in emotional responses to pain.
In the past, some researchers have thought that the pain reported by fibromyalgia patients was the result of depression rather than symptoms of a disorder. "Interestingly, we found that these functional abnormalities were independent of anxiety and depression status," Guedj said.
According to Guedj, disability is frequently used in controlled clinical trials to evaluate response to treatment. Because molecular imaging techniques such as SPECT can help predict a patient's response to a specific treatment and evaluate brain-processing recovery during follow-up, it could prove useful when integrated into future pharmacological controlled trials.
"Fibromyalgia may be related to a global dysfunction of cerebral pain-processing," Guedj added. "This study demonstrates that these patients exhibit modifications of brain perfusion not found in healthy subjects and reinforces the idea that fibromyalgia is a 'real disease/disorder.'"
I wonder whether niacin flushing or drugs that dilate capillaries might lessen the symptoms of fibromyalgia. Does the hyperperfusion cause pain just as much as the hypoperfusion? Or is the altered blood flow a result of the same underlying cause of the pain?
A larger number of facial nerves may provide one explanation for why women feel more pain.
ARLINGTON HEIGHTS, Ill. – For centuries, it has been generally believed women are the more sensitive gender. A new study says that, when it comes to pain, women are in fact more sensitive. According to a report published in October's Plastic and Reconstructive Surgery®, the official medical journal of the American Society of Plastic Surgeons (ASPS), women have more nerve receptors, which cause them to feel pain more intensely than men.
"This study has serious implications about how we treat women after surgery as well as women who experience chronic pain," said Bradon Wilhelmi, MD, ASPS member and author of the study. "Because women have more nerve receptors, they may experience pain more powerfully than men, requiring different surgical techniques, treatments or medicine dosages to help manage their pain and make them feel comfortable."
According to the study, women averaged 34 nerve fibers per square centimeter of facial skin while men only averaged 17 nerve fibers. Despite psychosocial expectations for men to be tougher than women when feeling pain, these findings illustrate that women's lower pain tolerance and threshold are physical.
But does the higher concentration of nerve fibers in the face of women reflect a similar difference between men and women in other parts of their bodies? I suspect not.
Also, I've come across lots of studies that contradict each other on the question of whether men or women have lower pain thresholds or feel more pain. Thinking about this study a thought occurs: Maybe men have lower pain thresholds for some parts of the body while women do for other parts. Or perhaps maybe men and women have different ratios of pain sensitivity for acute versus chronic pain.
Most plastic surgeries are done on women.
"Eighty-seven percent of the 9.2 million cosmetic surgery procedures performed last year were on women," said Dr. Wilhelmi. "The ability to minimize pain often affects a patient's perception of their results. We hope this data will give new perspective on how to better treat post-operative pain in women."
A lot of people are feeling pain.
Currently, 15 to 20 percent of the U.S. population suffers from acute pain, says Dr. Wilhelmi, while 25 to 30 percent suffer from chronic pain.