Regional Gray Matter Density Changes in Brains of Patients with Irritable Bowel Syndrome.
Gastroenterology. 2010 Mar 25;
Authors: Seminowicz DA, Labus JS, Bueller JA, Tillisch K, Naliboff BD, Bushnell MC, Mayer EA
BACKGROUND & AIMS:: Several studies have examined structural brain changes associated with chronic pain syndromes, including irritable bowel syndrome (IBS), but study sample sizes have been small and heterogeneous. METHODS:: We used magnetic resonance imaging (MRI)-based techniques, voxel-based morphometry, and cortical thickness analysis, to examine brain anatomical differences in a relatively large, tightly screened sample of IBS patients (n=55); we compared data with that from healthy individuals (controls, n=48). RESULTS:: IBS was associated with decreased gray matter density (GMD) in widespread areas of the brain, including medial prefrontal and ventrolateral prefrontal cortex, posterior parietal cortex, ventral striatum, and thalamus. Compared with controls, we observed increased GMD in patients with IBS in the pregenual anterior cingulate cortex and the orbitofrontal cortex, as well as trends in the posterior insula/secondary somatosensory cortex, (para)hippocampus, and left dorsolateral prefrontal cortex. In accounting for anxiety and depression, we found that several of the regions involved in affective processing no longer differed between patients with IBS and controls, whereas the differences in prefrontal and posterior parietal cortices remained. The areas of decreased GMD associated with IBS were largely consistent across clinical subgroups, based on predominant bowel habit and pain predominance of symptoms. There were no overall or regional differences in cortical thickness between patients with IBS and controls. CONCLUSIONS:: Changes in density of gray matter among regions involved in cognitive/evaluative functions are specifically observed in patients with IBS, whereas changes in other areas of the brain can be accounted for explained by levels of anxiety and depression.
PMID: 20347816 [PubMed - as supplied by publisher]
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