Cerebral Activation in Patients With Irritable Bowel Syndrome and Control Subjects During Rectosigmoid Stimulation

Abstract

IBS patients show altered brain responses to rectal stimuli, regardless of whether these stimuli are actually delivered or simply anticipated. These alterations are consistent with reported alterations in autonomic and perceptual responses and may be related to altered central noradrenergic modulation.

Regional brain activation in conscious, nonrestrained rats in response to noxious visceral stimulation

“…Several human studies also showed activation in the striatum in response to CRD [5,52,63] or gastric distention [37] in normal subjects. Neuroanatomical evidence suggests that nociceptive information may reach the basal ganglia through several afferent sources including the medial and posterior thalamus, amygdala, PBN area, dorsal raphe nucleus, as well as cortical regions.…”

“…In healthy human subjects, amygdala activation has been reported in response to gastric dis-tension [42], whereas decrease in activation has been reported in response to CRD (at least in female subjects) [5,11,52,63], though these studies have not provided information on subnuclei. In patients with IBS both increased activation [11] and no change [5,52,63] have been reported in response to CRD. The discrepancy may be attributable to differences in the experimental design and differences in CRD delivery parameters.…”

“…To date, the majority of human studies in this field have used distension of the rectosigmoid colon [4,5,8,41,44,48,52,62], stomach [37,69], and esophagus [2,3,9,73]. Activation of the insular and dorsal anterior cingulate cortex (dACC) has been most consistently reported, with other brain regions, including the prefrontal cortex, thalamus and brainstem being reported in some, but not in other studies.…”

Mapping of Brain Activations to Rectal Balloon Distension Stimuli in Male Patients with Irritable Bowel Syndrome Using Functional Magnetic Resonance Imaging

“…Functional imaging studies using positron emission tomography and fMRI revealed that patients with IBS often have exaggerated activation of cerebral sensory areas, especially emotional areas of brain following visceral stimulation as compared to healthy subjects. [12][13][14][15][16][17][18][19][20] Evidence from these studies indicates differential activation of the anterior cingulate cortex (ACC), prefrontal cortex (PFC), thalamus, insular cortex, and other limbic brain regions during colorectal stimulation, heterotopic stimulation or rectal balloon distension in IBS patients compared with healthy subjects. [12][13][14][15]18 Furthermore, resting state fMRI study performed on IBS patients demonstrated increased spontaneous neuronal activity in visceral afferent processing regions, while decreased regional brain activity in cognitive and pain regulatory regions.…”

The development of functional gastrointestinal diseases: Genetic aspects

“…В исследовании [5] по-лучены данные, что у пациентов с СРК -носителей гена 5-HTTLPR отмечается увеличение регионального кровотока в го-ловном мозге в ответ на растяжение кишечника, особенно выра-женное в коре орбитофронтальной области. Аналогичные ре-зультаты в ответ на стимуляцию ректосигмоидного отдела ки-шечника получены и в другом исследовании [24]. Принимая во внимания эти данные, можно отметить, что у пациентов с СРК повышение болевой чувствительности кишечника сопровожда-ется повышением активности участков мозга, ответственных за эмоциональную сферу.…”