Using 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 parts of the brain where pain is processed, according to a study in the November issue of the Journal of Nuclear Medicine.
“Fibromyalgia is frequently considered an 'invisible syndrome' since musculoskeletal imaging is negative," said the study’s lead author Eric Guedj, MD, and a researcher at Centre Hospitalier-Universitaire de la Timone. “Past imaging studies of patients with the syndrome, however, have shown above-normal cerebral blood flow 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, 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 then the researchers determined positive and negative correlations.
The investigators confirmed that patients with the syndrome exhibited brain perfusion abnormalities in comparison to the healthy subjects, and that abnormalities were directly correlated with the severity of the disease. The investigators reported that hyperperfusion was found in that region of the brain known to discriminate pain intensity, and hypoperfusion was found within those areas thought to be involved in emotional responses to pain.
In the past, 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.”