By: Dr Alex Robber
Researchers at the University of Colorado Boulder have identified a brain signature that recognizes patients with fibromyalgia with 93 per cent specificity, a possible advance for future clinical diagnosis and highly prevalent disease treatment.
Fibromyalgia is generally characterized as chronic widespread musculoskeletal pain, with symptoms such as fatigue, anxiety, and mood disorders. The Centers for Disease Control and Prevention (CDC) reports that in the U.S., fibromyalgia affects more than five million people annually, with prevalence rates slightly higher in women than in men.
Historically, because of a lack of well-categorized tissue pathology and symptoms which overlap with other common chronic diseases, fibromyalgia has been difficult to diagnose and treat.
Diagnostic marker for fibromyalgia
Scientists have used a multisensory approach to define a brain signature that separates individuals with fibromyalgia from those without it to establish an objective diagnostic test for fibromyalgia. Of the 72 participating participants, all of whom were females, 37 had a confirmed fibromyalgia diagnosis according to the guidelines of the American College of Rheumatology in 1990.
The remaining 35 were safe controls balanced for age, educational status, and handiness (all were right-handed). Participants were subjected to visual and auditory stimuli and were asked to perform a task of finger opposition.
A neurological pain signature (NPS) based on functional magnetic resonance imaging (fMRI) (previously established to predict experimental pain and differentiate it from other unpleasant / arousing emotional experiences) has been applied to subjects during pain treatment. However, researchers segregated patients with fibromyalgia from healthy controls using patterns of activation during painful pressure (FM-pain) and without intense, multi-sensory stimulation.
When exposed to the same painful stimuli patients with fibromyalgia reported greater NPS than healthy participants. In addition, this composite classifier was able to distinguish patients from healthy participants with 92 percent sensitivity when pattern response values for NPS, FM pain, and multisensory patterns were composite using logistic regression.
To Wager, PhD, director of the cognitive and affective neuroscience laboratory and professor in the psychology and neuroscience department and the University of Colorado’s Institute of Cognitive Science, Boulder, and author of the study, said, “Abnormal responses to multisensory experiences were the best individual predictors of whether a person had fibromyalgia. This means it is a neurological condition which is systemic rather than pain specific.
MRI scans (fMRI) to study brain activity
CU Boulder researchers used functional MRI scans (fMRI) to study brain activity in a group of 37 patients with fibromyalgia and 35 patients with control as they were exposed to a number of non-painful visual, auditory, tactile, and painful pressure signals.
The multisensory testing allowed the researchers to identify a series of three submarkers, or neurological patterns, that correlated with the pain hypersensitivity characterizing fibromyalgia. “The significance of this study is that it offers possible neuroimaging-based methods that can be used with new patients to educate them about the degree of some neural dysfunction that underlies their pain symptoms,” said Marina López-Solà, a post-doctoral researcher at CU Boulder’s Cognitive and Affective Regulation Laboratory and lead author of the new study.
“The collection of resources may be helpful in recognizing patient subtypes which may be critical for individualized modification of treatment selection.” The results have recently been published in the journal PAIN, published by the International Association for the Study of Pain.
Fibromyalgia is a disorder of central nervous system
“While many pain specialists have developed clinical protocols for fibromyalgia diagnosis, the clinical label does not clarify what is happening neurologically and it does not show the complete complexity of the suffering of patients,” said Tor Wager, director of the Cognitive and Affective Control Laboratory.
“The promise for brain interventions like those we have established here is that they can teach us much about the specific disorders of the brain that cause the suffering of an person. It will allow all us to understand fibromyalgia as a central nervous system condition-and manage it more effectively.
“If repeated and extended in future research, the findings could potentially provide a neural blueprint for brain activity that would guide fibromyalgia diagnosis and therapeutic treatments.
Neuropathophysiologic basis for the unique syndrome of fibromyalgia
Identifying a fibromyalgia-specific brain signature has the potential to send the medical community well ahead of previous notion that the disorder is in the heads of patients. According to Daniel G. Arkfeld, MD, associate professor of clinical medicine at the University of Southern California’s Keck School of Medicine (USC) and director of rheumatological education at USC’s Keck Hospital, “It’s an old myth that fibromyalgia is a developed condition that doesn’t exist.
Research such as this and others that have demonstrated elevated levels of substance P [a pain-promoting or algesic neurotransmitter] in the spinal fluid of fibromyalgic patients indicate that there is a neuropathophysiological basis for the specific fibromyalgia syndrome.
Finding the best treatment
Usage of such a brain signature has effects that go beyond enhancing treatment of fibromyalgia. “In fibromyalgia objective measures are required. This work can help point to appropriate targets for a more oriented approach to fibromyalgia care, “Dr Arkfeld said. Dr Wager agreed, “We need to classify patients and group them based on the neuropathology that underlies them. Then we have a better chance to find the right therapies that are based on biology of a person.
- Neural Signature for Fibromyalgia May Aid Diagnosis, Treatment by University of Colorado at Boulder via laboratoryequipment.com