Altered viscerotopic cortical innervation in patients with irritable bowel syndrome

• Published in: Neurogastroenterology and motility Vol. 27; no. 8; pp. 1075 - 1081
• Main Authors: Irimia, A., Labus, J. S., Torgerson, C. M., Van Horn, J. D., Mayer, E. A.
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.08.2015
• Subjects: Adult; Brain; connectomics; Diffusion Tensor Imaging; Female; Humans; Irritable bowel syndrome; Irritable Bowel Syndrome - pathology; Magnetic Resonance Imaging; Male; neuroimaging; NMR; Nuclear magnetic resonance; somatosensory cortex; Somatosensory Cortex - pathology; White Matter - pathology; diffusion tensor imaging; connectomics; magnetic resonance imaging; somatosensory cortex; irritable bowel syndrome; neuroimaging
• ISSN: 1350-1925; 1365-2982
• DOI: 10.1111/nmo.12586

Background Studies have demonstrated the existence of regional gray matter and white matter (WM) alterations in the brains of patients with irritable bowel syndrome (IBS), but the extent to which altered anatomical connectivity between brain regions is altered in IBS remains incompletely understood. Methods In this study, magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) were used to identify significant brain connectivity differences between IBS patients and healthy control (HC) subjects. Based on MRI and DTI volumes acquired from 66 IBS patients and 23 HC subjects, multivariate regression was used to investigate whether subject age, sex, cortical thickness, or the mean fractional anisotropy (FA) of WM connections innervating each location on the cortex could predict IBS diagnosis. Key Results HC and IBS subjects were found to differ significantly within both left and right viscerotopic portions of the primary somatosensory cortex (S1), with the mean FA of WM bundles innervating S1 being the predictor variable responsible for these significant differences. Conclusions & Inferences These preliminary findings illustrate how a chronic visceral pain syndrome and brain structure are related in the cohort examined, and because of their indication that IBS diagnosis is associated with anatomic neuropathology of potential neurological relevance in this patient sample. View the podcast on this paper at the following sites: iTunes: https://itunes.apple.com/gb/podcast/neurogastroenterology-motility/id1003210803 Youtube: https://www.youtube.com/watch?v=5ysaCCTfaI8&feature=em-upload_owner Visual representation of WM connections innervating S1 in a representative study patient. Depicted is a frontal view of the left and right postcentral gyri (red) together with the WM connections innervating S1. WM tracts connecting the postcentral gyri to the corticospinal tracts are drawn in bright green and highlighted by green arrows.