Yang Chen-Ya, Liang Muh-Lii, Chen Hsin-Hung, Chiu Jan-Wei, Liao Kwong-Kum, Yang Tsui-Fen
1Department of Physical Medicine and Rehabilitation, Taipei Veterans General Hospital.
Departments of2Neurosurgery and.
J Neurosurg Spine. 2018 Oct;29(4):456-460. doi: 10.3171/2018.2.SPINE171240. Epub 2018 Jul 13.
The aim of this study was to investigate the feasibility of using subdural strip electrodes, placed just rostral to the surgical field, to record sensory evoked potentials (SEPs) from the lumbosacral sensory nerves and define the most inferior functional portion of the conus medullaris during detethering surgery for spinal dysraphism and/or tethered cord syndrome (TCS).
Six patients, 2 boys and 4 girls, aged 0.5 to 16 years, were enrolled in this study. One patient had lipomyelomeningocele-related, 4 had myelomeningocele-related, and 1 had diastematomyelia and lipomyelomeningocele-related TCS. In addition to the routine preparations that are needed for performing functional mapping and monitoring during surgery for spinal dysraphism and TCS, the patients had a 1 × 4 strip of electrodes placed rostral to the surgical field, where it was secured by a surgeon after opening the dura. With the patient under total intravenous anesthesia, the sensory nerves and conus medullaris were stimulated with a concentric bipolar electrode over the surgical field while SEPs were recorded with the strip electrodes to identify any possible sensory roots with remaining function and the most inferior functional portion of the conus medullaris.
The SEP amplitudes that were recorded with the subdural strip electrodes ranged from 4 to 400 μV, and the responses to sensory nerve stimulation were frequently much larger than were those to conus stimulation. Use of the SEP recordings for sensory mapping along with the routine mapping and monitoring techniques allowed detethering to be completed such that none of the patients sustained any new functional deficit after surgery.
Recording SEPs from the functional sensory nerves and conus medullaris through subdural strip electrodes proved to be a feasible and valuable tool during detethering surgery in young patients. This approach may help surgeons achieve maximal detethering while preserving important sensory functions, consequently retaining the patient's quality of life.
本研究旨在探讨在脊髓脊膜膨出和/或脊髓拴系综合征（TCS）的脊髓松解手术中，使用置于手术区域前方的硬膜下条形电极记录腰骶部感觉神经的感觉诱发电位（SEP）并确定脊髓圆锥最下部功能部分的可行性。
本研究纳入了6例患者，年龄在0.5至16岁之间，其中2例为男孩，4例为女孩。1例患者患有脂肪瘤型脊髓脊膜膨出相关疾病，4例患有脊髓脊膜膨出相关疾病，1例患有脊髓纵裂和脂肪瘤型脊髓脊膜膨出相关的TCS。除了脊髓脊膜膨出和TCS手术中进行功能定位和监测所需的常规准备外，患者在手术区域前方放置了一条1×4的电极条，在打开硬脑膜后由外科医生固定。患者在全静脉麻醉下，通过手术区域上方的同心双极电极刺激感觉神经和脊髓圆锥，同时用条形电极记录SEP，以识别任何可能仍有功能的感觉神经根以及脊髓圆锥最下部的功能部分。
硬膜下条形电极记录的SEP波幅范围为4至400μV，感觉神经刺激的反应通常比对脊髓圆锥刺激的反应大得多。将SEP记录用于感觉定位以及常规的定位和监测技术，使得脊髓松解得以完成，术后没有患者出现任何新的功能缺陷。
在年轻患者的脊髓松解手术中，通过硬膜下条形电极记录功能感觉神经和脊髓圆锥的SEP被证明是一种可行且有价值的工具。这种方法可能有助于外科医生在保留重要感觉功能的同时实现最大程度的脊髓松解，从而维持患者的生活质量。
