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Neurobiologic Features of Fibromyalgia Are Also Present Among Rheumatoid Arthritis Patients
Author(s) -
Basu Neil,
Kaplan Chelsea M.,
Ichesco Eric,
Larkin Tony,
Harris Richard E.,
Murray Alison,
Waiter Gordon,
Clauw Daniel J.
Publication year - 2018
Publication title -
arthritis and rheumatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.106
H-Index - 314
eISSN - 2326-5205
pISSN - 2326-5191
DOI - 10.1002/art.40451
Subject(s) - fibromyalgia , medicine , rheumatoid arthritis , insula , functional magnetic resonance imaging , default mode network , functional connectivity , magnetic resonance imaging , rheumatology , physical therapy , psychology , neuroscience , radiology
Objective Many patients with rheumatoid arthritis ( RA ) report pain despite excellent control of inflammation with immunotherapies. Variable degrees of coexisting fibromyalgia ( FM ) may explain this disparity. FM has been characterized by aberrant brain functional connectivity, especially between the default mode network ( DMN ) and insula. We undertook this study to test the hypothesis that RA patients with the highest 2011 American College of Rheumatology FM survey criteria scores—a continuous measure of the degree of FM also known as “fibromyalgianess” ( FM ness)—would demonstrate functional connectivity abnormalities similar to those in FM . Methods RA patients underwent an 11‐minute functional connectivity magnetic resonance imaging ( MRI ) brain scan and a clinical evaluation which included a measure of FM ness. Brain networks were isolated from functional connectivity MRI data. Individual patient network‐to–whole brain connectivity analyses were then conducted, followed by group‐level regression, which correlated the connectivity of each network with FM ness. Results were significant on the cluster level with a family‐wise error ( FWE ) rate P value less than 0.05 derived from an uncorrected voxel‐level P value less than 0.001. Results A total of 54 patients participated (mean age 54.9 years, 75.9% women, mean FM ness score 13.2 [range 1–29]). From the whole brain analyses, a single significant positive correlation between DMN connectivity to the left mid/posterior insula and FM ness (r = 0.58, FWE ‐corrected P = 0.001) was demonstrated. Conclusion RA patients who have increased levels of FM ness appear to share neurobiologic features consistently observed in FM patients. This study is the first to provide neuroimaging evidence that RA is a mixed pain state, with many patients’ symptoms being related to the central nervous system rather than to classic inflammatory mechanisms.