Attempt to replicate voxel-based morphometry analysis in fibromyalgia: Detection of below threshold differences framed by contributions of variable clinical presentation to low reproducibility.

BackgroundFibromyalgia is a prevalent chronic pain condition characterized by widespread pain and sensory hypersensitivity. While much remains unknown about fibromyalgias neurobiological underpinnings, central nervous system alterations appear to be heavily implicated in its pathophysiology. Previous research examining brain structural abnormalities associated with fibromyalgia has yielded inconsistent findings. Thus, we followed previous methods to examine brain gray matter differences in fibromyalgia. We hypothesized that, relative to healthy controls, participants with fibromyalgia would exhibit lower gray matter volume in regions consistently implicated in fibromyalgia: the anterior cingulate cortex and medial prefrontal cortex. MethodsThis study used magnetic resonance imaging to evaluate regional and whole brain differences in gray matter among females with and without fibromyalgia. Group differences were analyzed with two-sample t-tests, controlling for total intracranial volume. ResultsNo significant differences in regional or whole brain gray matter volumes were detected between fibromyalgia and healthy controls. ConclusionsResults add to an existing body of disparate findings regarding brain gray matter volume differences in fibromyalgia, and suggest structural differences previously detected in fibromyalgia should be examined for reproducibility. Absent significant differences may also suggest that functional, but not structural, brain adaptations are primarily associated with fibromyalgia.