Endogenous Opioid Systems and Symptom Change in Fibromyalgia

Summary

Participation Requirements

Description

The purpose of this study is to examine µ-opioid receptor (µOR)-mediated neurotransmission in patients diagnosed with persistent pain, fibromyalgia (FM), and its relationship with pain and affect measures. µOR activation is expected to take place in the following brain regions: rostral and dorsal an...

The purpose of this study is to examine µ-opioid receptor (µOR)-mediated neurotransmission in patients diagnosed with persistent pain, fibromyalgia (FM), and its relationship with pain and affect measures. µOR activation is expected to take place in the following brain regions: rostral and dorsal anterior cingulate (rACC, dACC), orbitofrontal cortex (OFC), thalamus (THA), nucleus accumbens (NAC), amygdala (AMY), periaqueductal gray (PAG). Greater regional activation is expected to be associated with improvements in clinical pain ratings and affective state. The endogenous opioid system and µ-opioid receptors (µORs) play a central role in the regulation of pain, the pathophysiology of chronic pain syndromes, mood and emotion; this system is dysregulated in persistent pain syndromes. A substantial body of literature addressing these mechanisms has been developed in our laboratory, including recent data on the cognitive and molecular mechanisms associated with reductions in pain, as well as trait personality and genetic predictors of emotional effects in the context of pain. Eighty individuals who have been diagnosed with FM and who fit the inclusion and exclusion criteria will be enrolled in this 14-week protocol. An initial visit for informed consent procedures and baseline characterization will then be scheduled, as well as the visits for positron emission tomography (PET) and magnetic resonance imaging (MRI) procedures. Subjects will return for testing after 6 and 14 weeks. Volunteers will undergo imaging with structural and functional MRI and PET with [11C]carfentanil to determine baseline µOR non-displaceable binding potential (BPND) and changes in those BPND measures coinciding with symptom severity at the time of scanning.

Tracking Information