Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022104 (irritable bowel syndrome)
 8,033 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In healthy subjects, the brain regions most consistently activated in visceral and somatic pain are the key regions in the central pain matrix,including the mid/anterior insula, subregions of the ACC, PFC, thalamus,and in some cases, pontine regions such as the dorsal pons and PAG. Functional neuroimaging studies have demonstrated evidence of altered regional brain activation responses during visceral and somatic stimuli in IBS that have been associated with perceptual differences. Although perceptual studies have shown increased sensitivity to rectosigmoid distension in IBS, most somatic pain studies have demonstrated normal or decreased sensitivity compared with controls; however, a recent study showed increased sensitivity to thermal heat. Altered brain responses in IBS,particularly to visceral stimuli, include activation of regions concerned with attentional processes and response selection, corticolimbic regions concerned with emotional and autonomic responses to stimuli, and subcortical regions receiving cortical projections from the latter and afferent input from the soma and viscera. Altered activations of these regions also may be present in the absence of a noxious visceral stimulus. Changes in rCBF of some of these regions have been associated with treatment response in IBS. With regard to differences in cortical processing of visceral versus somatic stimuli in IBS, there have been only two studies. Greater activations of the dorsal ACC, thalamus, and PFC have been shown with visceral stimuli compared with somatic stimuli in IBS. A plausible hypothesis for the observations from brain imaging studies is that IBS patients demonstrate a compromised activation of pain inhibition circuits including those of the cortico-pontine circuit but increased activation of limbic and paralimbic circuits that may be related to pain facilitation.
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PMID:Brain responses to visceral and somatic stimuli in irritable bowel syndrome: a central nervous system disorder? 1586 35

Irritable bowel syndrome (IBS) is a disorder involving dysfunctional brain-gut interactions characterized by chronic recurrent abdominal pain, altered bowel habits, and negative emotion. Previous studies have linked the habenula to the pathophysiology of negative emotion and pain. However, no studies to date have investigated habenular function in IBS patients. In this study, we investigated the resting-state functional connectivity (rsFC) and effective connectivity of the habenula in 34 subjects with IBS and 34 healthy controls and assessed the feasibility of differentiating IBS patients from healthy controls using a machine learning method. Our results showed significantly enhanced rsFC of the habenula-left dorsolateral prefrontal cortex (dlPFC) and habenula-periaqueductal grey (PAG, dorsomedial part), as well as decreased rsFC of the habenula-right thalamus (dorsolateral part), in the IBS patients compared with the healthy controls. Habenula-thalamus rsFC was positively correlated with pain intensity (r = .467, p = .005). Dynamic causal modeling (DCM) revealed significantly decreased effective connectivity from the right habenula to the right thalamus in the IBS patients compared to the healthy controls that was negatively correlated with disease duration (r = -.407, p = .017). In addition, IBS was classified with an accuracy of 71.5% based on the rsFC of the habenula-dlPFC, habenula-thalamus, and habenula-PAG in a support vector machine (SVM), which was further validated in an independent cohort of subjects (N = 44, accuracy = 65.2%, p = .026). Taken together, these findings establish altered habenular rsFC and effective connectivity in IBS, which extends our mechanistic understanding of the habenula's role in IBS.
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PMID:Altered resting-state functional connectivity and effective connectivity of the habenula in irritable bowel syndrome: A cross-sectional and machine learning study. 3248 29