Specialist Colorectal and Pelvic Floor Centre, Sydney, New South Wales, Australia.
Academic Colorectal Unit, Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia.
Colorectal Dis. 2017 Oct;19(10):917-926. doi: 10.1111/codi.13694.
Continence is dependent on anorectal-brain interactions. Consequently, aberrations of the brain-gut axis may be important in the pathophysiology of faecal incontinence (FI) in certain patients. The aim of this study was to assess the feasibility of recording brain responses to rectal mechanical stimulation in patients with FI using functional magnetic resonance imaging (fMRI).
A prospective, cohort pilot study was performed to assess brain responses during rectal stimulation in 14 patients [four men, mean (SD) age 62 (15) years]. Blood oxygen level dependent (BOLD) signals were measured by fMRI during rest and mechanical distension, involving random repetitions of isobaric phasic rectal distensions at fixed (15 and 45 mmHg) and variable (10% above sensory perception threshold) pressures.
Increases in BOLD signals in response to high pressure rectal distension (45 mmHg) and maximum toleration were observed in the cingulate gyrus, thalamus, insular cortex, inferior frontal gyrus, cerebellum, caudate nucleus, supramarginal gyrus, putamen and amygdala. Additionally, activation of the supplementary motor cortex and caudate nucleus with inconsistent activity in the frontal lobe was observed.
This study has demonstrated the feasibility of recording brain responses to rectal mechanical stimulation using fMRI in patients with FI, revealing activity in widespread areas of the brain involved in visceral sensory processing. The observed activity in the supplementary motor cortex and caudate nucleus, with relative paucity of activity in the frontal lobes, warrants investigation in future studies to determine whether aberrations in cerebral processing of rectal stimuli play a role in the pathogenesis of FI.
控便能力取决于肛肠-脑相互作用。因此，在某些患者中，脑-肠轴的异常可能在大便失禁（FI）的病理生理学中起重要作用。本研究旨在评估使用功能磁共振成像（fMRI）记录 FI 患者直肠机械刺激时大脑反应的可行性。
前瞻性队列初步研究评估了 14 名患者（4 名男性，平均年龄 62（15）岁）在直肠刺激期间的大脑反应。通过 fMRI 在休息和机械扩张期间测量血氧水平依赖（BOLD）信号，包括在固定（15 和 45mmHg）和可变（高于感觉感知阈值 10%）压力下对等容相直肠扩张的随机重复。
在高压直肠扩张（45mmHg）和最大耐受时观察到扣带回、丘脑、岛叶皮质、下额回、小脑、尾状核、缘上回、壳核和杏仁核的 BOLD 信号增加。此外，还观察到补充运动皮质和尾状核的激活，额叶活动不一致。
本研究证明了在 FI 患者中使用 fMRI 记录直肠机械刺激时大脑反应的可行性，揭示了涉及内脏感觉处理的广泛大脑区域的活动。在补充运动皮质和尾状核中观察到的活动，而额叶活动相对较少，值得在未来的研究中进一步研究，以确定直肠刺激的大脑处理异常是否在 FI 的发病机制中起作用。
