Gross Robert E, Sung Edward K, Mulligan Patrick, Laxpati Nealen G, Mayo Darlene A, Rolston John D
Departments of1Neurosurgery and.
2Neurology, Emory University School of Medicine, Atlanta, Georgia.
J Neurosurg. 2019 Mar 22;132(3):681-691. doi: 10.3171/2018.12.JNS18749. Print 2020 Mar 1.
Various techniques are available for stereotactic implantation of depth electrodes for intracranial epilepsy monitoring. The goal of this study was to evaluate the accuracy and effectiveness of frameless MRI-guided depth electrode implantation.
Using a frameless MRI-guided stereotactic approach (Stealth), depth electrodes were implanted in patients via burr holes or craniotomy, mostly into the medial temporal lobe. In all cases in which it was possible, postoperative MR images were coregistered to planning MR images containing the marked targets for quantitative analysis of intended versus actual location of each electrode tip. In the subset of MR images done with sufficient resolution, qualitative assessment of anatomical accuracy was performed. Finally, the effectiveness of implanted electrodes for identifying seizure onset was retrospectively examined.
Sixty-eight patients underwent frameless implantation of 413 depth electrodes (96% to mesial temporal structures) via burr holes by one surgeon at 2 institutions. In 36 patients (203 electrodes) planning and postoperative MR images were available for quantitative analysis; an additional 8 procedures with 19 electrodes implanted via craniotomy for grid were also available for quantitative analysis. The median distance between intended target and actual tip location was 5.19 mm (mean 6.19 ± 4.13 mm, range < 2 mm-29.4 mm). Inaccuracy for transtemporal depths was greater along the electrode (i.e., deep), and posterior, whereas electrodes inserted via an occipital entry deviated radially. Failure to localize seizure onset did not result from implantation inaccuracy, although 2 of 62 patients (3.2%)-both with electrodes inserted occipitally-required reoperation. Complications were mostly transient, but resulted in long-term deficit in 2 of 68 patients (3%).
Despite modest accuracy, frameless depth electrode implantation was sufficient for seizure localization in the medial temporal lobe when using the orthogonal approach, but may not be adequate for occipital trajectories.
有多种技术可用于立体定向植入深部电极以进行颅内癫痫监测。本研究的目的是评估无框架MRI引导下深部电极植入的准确性和有效性。
采用无框架MRI引导的立体定向方法（Stealth），通过钻孔或开颅手术将深部电极植入患者体内，主要植入内侧颞叶。在所有可行的病例中，术后MR图像与包含标记靶点的计划MR图像进行配准，以对每个电极尖端的预期位置与实际位置进行定量分析。在具有足够分辨率的MR图像子集中，进行解剖准确性的定性评估。最后，回顾性检查植入电极识别癫痫发作起始的有效性。
一名外科医生在2家机构为68例患者通过钻孔进行了413根深部电极的无框架植入（96%植入内侧颞叶结构）。36例患者（203根电极）有计划和术后MR图像可用于定量分析；另外8例通过开颅手术植入格栅的19根电极的手术也可用于定量分析。预期靶点与实际尖端位置之间的中位距离为5.19 mm（平均6.19±4.13 mm，范围<2 mm - 29.4 mm）。经颞叶深度的误差沿电极（即深部）和后部更大，而通过枕部入路插入的电极呈径向偏离。未能定位癫痫发作起始并非由植入不准确导致，尽管62例患者中有2例（3.2%）——均为经枕部插入电极——需要再次手术。并发症大多为短暂性，但68例患者中有2例（3%）出现长期功能缺损。
尽管准确性一般，但使用正交入路时，无框架深部电极植入足以在内侧颞叶定位癫痫发作，但对于枕部轨迹可能不够。
