Department of Urology, Antwerp University Hospital (UZA), Edegem, Belgium.
Faculty of Medicine and Health Sciences, University of Antwerp (UA), Antwerp, Belgium.
Neurourol Urodyn. 2020 Aug;39(6):1815-1823. doi: 10.1002/nau.24425. Epub 2020 Jun 25.
To assess the activation of the different parts of the pelvic floor muscles (PFM) upon electrical stimulation of the sacral spinal nerves while comparing the different lead electrode configurations.
PFM electromyography (EMG) was recorded using an intravaginal multiple array probe with 12 electrodes pairs, which allows to make a distinction between the different sides and depths of the pelvic floor. In addition concentric needle EMG of the external anal sphincter was performed to exclude far-field recording. A medtronic InterStim tined lead (model 3889) was used as stimulation source. Standard SNM parameters (monophasic pulsed square wave, 210 microseconds, 14 Hz) were used to stimulate five different bipolar electrode configurations (3+0-/3+2-/3+1-/0+3-/1+3-) up to and around the sensory threshold. Of each EMG signal the stimulation intensity needed to evoke the EMG signals as well as its amplitude and latency were determined. Linear mixed models was used to analyse the data.
Twenty female patients and 100 lead electrode configurations were stimulated around the sensory response threshold resulting in 722 stimulations and 12 times as many (8664) EMG recordings. A significant increase in EMG amplitude was seen upon increasing stimulation intensity (P < .0001). Large differences were noted between the EMG amplitude recorded at the different sides (ipsilateral>posterior>anterior>contralateral) and depths (deep>center>superficial) of the pelvic floor. These differences were noted for all lead electrodes configurations stimulated (P < .0001). Larger EMG amplitudes were measured when the active electrode was located near the entry point of the sacral spinal nerves through the sacral foramen (electrode #3). No differences in EMG latency could be withheld, most likely due to the sacral neuroanatomy (P > .05).
A distinct activation pattern of the PFM could be identified for all stimulated lead electrode configurations. Electrical stimulation with the most proximal electrode (electrode #3) as the active one elicited the largest PFM contractions.
通过比较不同导联电极配置，评估骶神经根电刺激时盆底肌（PFM）不同部位的激活情况。
采用带有 12 对电极的阴道内多阵列探头记录 PFM 肌电图（EMG），可区分盆底的不同侧面和深度。此外，还进行了肛门外括约肌同心针 EMG 以排除远场记录。使用 Medtronic InterStim 带刺导联（型号 3889）作为刺激源。采用标准的 SNM 参数（单相脉冲方波，210μs，14Hz）刺激 5 种不同的双极电极配置（3+0-/3+2-/3+1-/0+3-/1+3-），直至感觉阈上。记录每种 EMG 信号的刺激强度、振幅和潜伏期。采用线性混合模型分析数据。
共刺激了 20 名女性患者和 100 个导联电极配置，直至感觉反应阈，共进行了 722 次刺激和 12 倍（8664）次 EMG 记录。随着刺激强度的增加，EMG 振幅显著增加（P<.0001）。在盆底的不同侧面（同侧>后侧>前侧>对侧）和深度（深层>中心>浅层）记录的 EMG 振幅存在较大差异。所有刺激的导联电极配置均观察到这种差异（P<.0001）。当活性电极位于骶神经根通过骶孔进入点附近（电极#3）时，可测量到较大的 EMG 振幅。由于骶神经解剖结构，无法检测到 EMG 潜伏期的差异（P>.05）。
对于所有刺激的导联电极配置，都可以识别出 PFM 的明显激活模式。用最靠近骶神经根进入点的电极（电极#3）作为活性电极进行电刺激可引起最大的 PFM 收缩。
