Abstract: Altered resting-state (RS) brain activity, as a measure of functional connectivity (FC), is commonly observed in chronic pain. Identifying a reliable signature pattern of altered RS activity for chronic pain could provide strong mechanistic insights and serve as a highly beneficial neuroimaging-based diagnostic tool. We collected and analyzed RS functional magnetic resonance imaging data from female patients with urologic chronic pelvic pain syndrome (N = 45) and matched healthy participants (N = 45) as part of an NIDDK-funded multicenter project (www.mappnetwork.org). Using dual regression and seed-based analyses, we observed significantly decreased FC of the default mode network to 2 regions in the posterior medial cortex (PMC): the posterior cingulate cortex (PCC) and the left precuneus (threshold-free cluster enhancement, family-wise error corrected P < 0.05). Further investigation revealed that patients demonstrated increased FC between the PCC and several brain regions implicated in pain, sensory, motor, and emotion regulation processes (eg, insular cortex, dorsolateral prefrontal cortex, thalamus, globus pallidus, putamen, amygdala, hippocampus). The left precuneus demonstrated decreased FC to several regions of pain processing, reward, and higher executive functioning within the prefrontal (orbitofrontal, anterior cingulate, ventromedial prefrontal) and parietal cortices (angular gyrus, superior and inferior parietal lobules). The altered PMC connectivity was associated with several phenotype measures, including pain and urologic symptom intensity, depression, anxiety, quality of relationships, and self-esteem levels in patients. Collectively, these findings indicate that in patients with urologic chronic pelvic pain syndrome, regions of the PMC are detached from the default mode network, whereas neurological processes of self-referential thought and introspection may be joined to pain and emotion regulatory processes.
In chronic pelvic pain, the posterior cingulate cortex is functionally detached from the default mode network and instead joined to pain and emotion processing regions.
aDepartment of Anesthesiology, Perioperative and Pain Medicine, Division of Pain Medicine, Stanford University, Stanford, CA, USA
bDepartment of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA
cDepartment of Physiology, Northwestern University, Chicago, IL, USA
dDepartment of Medicine, David Geffen School of Medicine, Division of Digestive Diseases, University of California, Los Angeles, CA, USA
eDepartment of Radiology, University of Alabama at Birmingham, Birmingham, AL, USA
fDepartment of Anesthesiology, University of Michigan Ann Arbor, Ann Arbor, MI, USA
Corresponding author. Address: Department of Anesthesiology, Perioperative and Pain Medicine, Division of Pain Medicine, Stanford University, 1070 Arastradero Rd, Room 285, MC 5596, Palo Alto, CA 94304-1336, USA. Tel.: +650 498-6477; fax: +650 725-9642. E-mail address: firstname.lastname@example.org (S. C. Mackey).
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Received February 12, 2015
Received in revised form May 01, 2015
Accepted May 12, 2015