Rapid rate magnetic stimulation of human sacral nerve roots alters excitability within the cortico-anal pathway
Rapid rate magnetic stimulation of human sacral nerve roots alters excitability within the cortico-anal pathway
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DOI：
10.1111/j.1365-2982.2008.01153.x
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发表时间：
2008-10-01
影响因子：
3.5
通讯作者：
Hamdy, S.
中科院分区：
文献类型：
--
作者：
Harris, M. L.;Singh, S.;Hamdy, S.
骶神经根刺激（SNS）可显著改善大便失禁（FI）的症状。然而，这种改善背后的生理机制仍然未知。一种假设是SNS可以调节皮质-肛门通路，并驱动脊髓或大脑皮质内的代偿性变化，从而有益地改变括约肌功能。我们的目的是评估短期实验SNS是否可以诱导人类皮质-肛门通路的变化。8名健康志愿者（平均年龄30岁）进行了研究。受试者在三个不同的场合进行了研究，并随机接受主动（5和15 Hz）或假快速腰骶磁刺激（rLSMS）。在基线、rLSMS后即刻、30 min和60 min，在（i）5 Hz持续15 min、（ii）15 Hz持续15 min或（iii）假刺激15 min条件下，单脉冲经颅磁刺激后通过肛门探头记录肛门括约肌肌电图（EMG）。此外，在一个受试者亚组中测量测压和肛门括约肌感觉。使用ANOVA将干预与假手术进行比较。15赫兹rLSMS在干预后1小时增加了皮质-肛门EMG反应幅度（F-4，F- 28 = 3.2，P = 0.027），而反应潜伏期没有变化。5 Hz或假刺激均未证明此效应。rLSMS对感觉或生理没有短期影响。短期磁刺激骶神经根引起皮质-肛门兴奋性的变化，这是频率特异性的。这些数据支持了SNS通过改变皮质-肛门通路的兴奋性对FI患者产生一些有益作用的假设。
Sacral nerve root stimulation (SNS) can produce dramatic symptomatic improvement in faecal incontinence (FI). However, the physiological mechanism behind this improvement remains unknown. One hypothesis is that SNS may modulate cortico-anal pathways and drive compensatory changes within the spinal cord or cerebral cortex that beneficially alter sphincter function. Our aim was to assess whether short-term experimental SNS can induce changes in the human cortico-anal pathway. Eight healthy volunteers (mean age 30 years) were studied. Subjects were investigated on three separate occasions and randomized to either active (5 and 15 Hz) or sham rapid-rate lumbosacral magnetic stimulation (rLSMS). Anal sphincter electromyograms (EMG) were recorded from an anal probe following single-pulse transcranial magnetic stimulation, at baseline, immediately, 30 and 60 min following rLSMS at either (i) 5 Hz for 15 min, (ii) 15 Hz for 15 min or (iii) sham stimulation for 15 min. In addition, manometry and anal sphincter sensation was measured in a subset of subjects. Interventions were compared to sham using ANOVA. Fifteen hertz rLSMS increased cortico-anal EMG response amplitude in the 1 h postintervention (F-4,F- 28 = 3.2, P = 0.027), without a shift in response latency. This effect was not demonstrated with either 5 Hz or sham stimulation. rLSMS had no short-term effect on sensation or physiology. Short-term magnetic stimulation of the sacral nerve roots induces changes in cortico-anal excitability which is frequency specific. These data support the hypothesis that SNS produces some of its beneficial effect in patients with FI by altering the excitability of the cortico-anal pathway.