肠易激综合征患者直肠扩张后脑诱发电位的研究

目的 通过比较直肠扩张后脑诱发电位(CEP)的改变,探讨肠易激综合征(IBS)患者内脏高敏感性的发生机制,旨在进一步获得IBS感觉传入通路异常的客观依据。方法 根据罗马Ⅱ标准选择女性IBS患者10例,其中腹泻型6例,便秘型2例,腹泻-便秘交替型2例,另设7例女性健康志愿者为对照组,对其进行直肠气囊扩张,首先测出每例受试者感觉阈值,用1.5倍该阈值空气体积作为刺激(频率1Hz,连续100次,休息10分钟,重复一次),启动并记录两组受试者CEP的变化。结果 直肠节律性机械扩张引出可识别、可复制的CEP。与健康对照者相比,IBS患者N_1,P_1,N_2潜伏期明显缩短(P<0.05),同时,峰间波幅有增大趋势,但无统计学意义(P>0.05)。结论 IBS患者经直肠扩张后产生的CEP的改变证实了其内脏高敏感性及内脏传入通路的异常。

A study on cerebral potentials evoked by rectal distension in patients with irritable bowel syndrome

Objective To study the mechanism of the visceral hypersensitivity in patients with irritable bowel syndrome (IBS) and try to obtain further objective evidence of alterations in intestinal afferent pathways in IBS patients through a new technique: cerebral evoked potentials (CEP) .Methods We Selected 10 female IBS patients according to Roman II diagnostic standard and 7 female healthy volunteers. Rectal perception thresholds to balloon distention were measured and CEP were recorded in response to rhythmic rectal distension (two distension series each of 100 repetitions at a frequency of 1 Hz) at an volume 50% above perception thresholds. Results Rectal distension led to recognizable and reproducible CEP. Compared to healthy subjects, IBS patients demonstrated significantly shorter N1 , P1 , N2 latencies, and N1 , P1 , N2 amplitudes were increased, but did not show significant difference. Conclusion The shorter latency and increased amplitude of cerebral potentials evoked by rectal distension in IBS patients provided further objective evidence for defective visceral afferent transmission in IBS patients .