Brain functional connectivity is associated with visceral sensitivity in women with Irritable Bowel Syndrome

Abstract

Increased perception of visceral stimuli is a key feature of Irritable Bowel Syndrome (IBS). While altered resting-state functional connectivity (rsFC) has been also reported in IBS, the relationship between visceral hypersensitivity and aberrant rsFC is unknown. We therefore assessed rsFC within the salience, sensorimotor and default mode networks in patients with and without visceral hypersensitivity and in healthy controls (HCs).An exploratory resting-state functional magnetic resonance imaging study was performed in 41 women with IBS and 20 HCs. Group independent component analysis was used to derive intrinsic brain networks. Rectal thresholds were determined and patients were subdivided into groups with increased (hypersensitive IBS, N = 21) or normal (normosensitive IBS, N = 20) visceral sensitivity. Between-group comparisons of rsFC were carried-out using region-of-interest analyses and peak rsFC values were extracted for correlational analyses.Relative to normosensitive IBS, hypersensitive patients showed increased positive rsFC of pregenual anterior cingulate cortex and thalamus within the salience network and of posterior insula within the sensorimotor network. When compared to both hypersensitive IBS and HCs, normosensitive IBS showed decreased positive rsFC of amygdala and decreased negative rsFC in dorsal anterior insula within the DMN. DMN and sensorimotor network rsFC were associated with rectal perception thresholds, and rsFC in posterior insula was correlated with reported symptom severity in IBS.Our exploratory findings suggest that visceral sensitivity in IBS is related to changes in FC within resting-state networks associated with interoception, salience and sensory processing. These alterations may play an important role in hypervigilance and hyperalgesia in IBS.

Sex‐related differences in resting‐state brain activity and connectivity in the orbital frontal cortex and insula in patients with functional constipation

“…Female patients with IBS showed an upregulation of emotional arousal circuits during an aversive rectal stimulus, and greater emotional arousal circuit activation was found during expectation of the rectal stimulus . Female patients with IBS also showed alterations in intrinsic oscillation in the INS and its functional connectivity . Like IBS and many other FGID, FC is more prevalence in women with a mean female to male ratio of 2.1:1 .…”

“…15 Female patients with IBS also showed alterations in intrinsic oscillation in the INS 8 and its functional connectivity. 16,17 Like IBS and many other FGID, FC is more prevalence in women with a mean female to male ratio of 2.1:1. 18,19 To the best of our knowledge, only one resting-state fMRI (RS-fMRI) study from our group has been performed in patients with FC and revealing brain abnormalities in regions implicated in emotional process modulation, somatic and sensory processing, and motor control.…”

Understanding Neurogastroenterology From Neuroimaging Perspective: A Comprehensive Review of Functional and Structural Brain Imaging in Functional Gastrointestinal Disorders

“…Icenhour et al 63 reported that resting-state functional connectivity value in the default mode network (DMN) (Fig. 3B) and the sensorimotor network was associated with rectal perception thresholds, and that the resting-state functional connectivity value in the posterior insula was correlated with the reported symptom severity in IBS.…”

Susceptibility to diarrhea is related to hemodynamic markers of sympathetic activation in the general population

“…Since our study is cross-sectional, the signs of cardiovascular autonomic dysfunction in patients with severe functional GI symptoms may be primary or secondary to the GI disease, with several possible explanations. First, autonomic neuropathy secondary to GI symptoms may be an effect of the peripheral and/or central hypersensitization associated with functional GI disorders [3], with aggravated ANS responses, due to afferent signals from the GI tract being dispersed to amygdala, hippocampus, insula, cingulate cortex and other brain centers modulating pain signals [5,29]. Second, a primary autonomic dysfunction such as present in genetic diseases [16], Parkinson's disease [10] or diabetes mellitus [9], may act as a causal agent disturbing both afferent and efferent pathways between the gut and brain.…”

“…The most prevalent manifestation of FGID is irritable bowel syndrome (IBS) [1]. It has been demonstrated that IBS is strongly related to stress, psychological disorders [2] and visceral hypersensitivity [3]. The enteric nervous system (ENS) is a part of the autonomic nervous system (ANS), which constitutes the anatomical and physiological basis for correlations between visceral hypersensitization and autonomic dysfunction [4].…”