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Corresponding Author: Farrell, Michael, PhD Category: 11. Soft tissue and regional musculoskeletal disease, fibromyalgia: studies of regional pain syndromes, local diseases of muscle, ligament and tendon fibromyalgia
ACR 65th Annual Scientific Meeting Filename: 23722316 Corresponding Author: Michael J Farrell PhD Dept: CMMU, PNMB Institution:Nat'l Institute of Dental & Craniofacial Research Address: Building 10, room 1N-103, Bethesda, MD, 20892 Phone: 301 402 0195 Fax:301 496 1005 E-mail:
[email protected] Award Consideration: Category: 11. Soft tissue and regional musculoskeletal disease, fibromyalgia: studies of regional pain syndromes, local diseases of muscle, ligament and tendon fibromyalgia Poster only Presentation: No Author Status: No member status indicated ACR Sponsor: Daniel J Clauw SUPRASPINAL ACTIVITY ASSOCIATED WITH PAINFUL PRESSURE IN FIBROMYALGIA (FM) IS ASSOCIATED WITH BELIEFS ABOUT LOCUS OF PAIN CONTROL Michael J Farrell PhD 1, John W VanMeter PhD 3, David Williams PhD 2, Julie M Wolf BA 1, Masilo AB Grant BA 1, Richard H Gracely PhD 1 and Daniel J Clauw MD2. 1 CMMU, PNMB, NIDCR, Bethesda, MD, 2Chronic Pain and Fatigue Research Center and 3Center for the Study of Learning, Georgetown University, Washington, DC. Aim: Functional MRI (fMRI) can examine changes in regional cerebral blood flow associated with painful stimulation. Previous fMRI studies in FM have indicated differences in pain processing, suggesting supraspinal pain amplification. This study examines the effect of an important clinical construct in chronic pain patients – their perceived locus of control of their pain – on regional blood flow patterns associated with painful pressure stimuli. Methods: Subjects (n=21) with fibromyalgia completed the study. Pressure was applied to subjects' left thumb nails in alternating 30 s blocks at innocuous and painful intensities for 10 min. Echo-planar images with TR= 5s, TE=40ms, 90degree flip angle, 64x64 matrix and 192mm field of view over 50 horizontal slices of 3mm thickness were obtained with a Siemens 1.5 Tesla scanner during stimulation. The fMRI data were corrected for head motion, spatially smoothed with a Gaussian filter (FWHM= 6mm< SUP > 3< /SUP> ) and ratio normalized. Mean differences in fMRI signal
between the painful and innocuous conditions were computed and transformed into the Taliarach atlas space allowing for inter-subject analyses and anatomical localization. Each subjects also completed the Beliefs in Pain Control Questionnaire (BPCQ). Correlations were computed at each voxel in the brain between the mean difference value and BPCQ subscale scores (Internal - I, Powerful Doctors - PD, Chance - C). A RESEL correction was applied to account for multiple comparisons. Correlations significant at p < 0.05 are reported here. Results: Relationships were demonstrated between BPCQ subscale scores and the average increase in blood flow as assessed with fMRI from the innocuous to painful condition - I with the right SII (r = 0.84), PD with bilateral inferior parietal gyri/BA40 (Right r = 0.82, Left r = 0.75), C with right superior temporal gyrus (STG)/BA 22 (r = 0.82). Conclusions: Endorsing a strong internal locus is associated with greater levels of pain related activity in SII possibly reflecting differential degrees of stimulus labeling and selective attention. Increased parietal activity associated with PD scores may indicate recruitment of cortico-limbic pathways involved in pain hedonics and affective responses. The implications of the relationship between C and STG activation are not readily apparent. The results of this study support the notion that beliefs about paincontrol influence central processing of noxious extrinsic stimuli. Disclosure: There is no information to disclose.
