Sommer Bjoern, Rampp Stefan, Doerfler Arnd, Stefan Hermann, Hamer Hajo M, Buchfelder Michael, Roessler Karl
a Department of Neurosurgery , University Hospital Erlangen , Erlangen , Germany.
b Department of Neuroradiology , University Hospital Erlangen , Erlangen , Germany.
Neurol Res. 2018 Oct;40(10):811-821. doi: 10.1080/01616412.2018.1484588. Epub 2018 Jun 19.
One of the main obstacles of electrode implantation in epilepsy surgery is the electrode shift between implantation and the day of explantation. We evaluated this possible electrode displacement using intraoperative MRI (iopMRI) data and CT/MRI reconstruction.
Thirteen patients (nine female, four male, median age 26 ± 9.4 years) suffering from drug-resistant epilepsy were examined. After implantation, the position of subdural electrodes was evaluated by 3.0 T-MRI and thin-slice CCT for 3D reconstruction. Localization of electrodes was performed with the volume-rendering technique. Post-implantation and pre-explantation 1.5 T-iopMRI scans were coregistered with the 3D reconstructions to determine the extent of electrode dislocation.
Intraoperative MRI at the time of explantation revealed a relevant electrode shift in one patient (8%) of 10 mm. Median electrode displacement was 1.7 ± 2.6 mm with a coregistration error of 1.9 ± 0.7 mm. The median accuracy of the neuronavigation system was 2.2 ± 0.9 mm. Six of twelve patients undergoing resective surgery were seizure free (Engel class 1A, median follow-up 37.5 ± 11.8 months).
Comparison of pre-explantation and post-implantation iopMRI scans with CT/MRI data using the volume-rendering technique resulted in an accurate placement of electrodes. In one patient with a considerable electrode dislocation, the surgical approach and extent was changed due to the detected electrode shift.
ECoG: electrocorticography; EZ: epileptogenic zone; iEEG: invasive EEG; iopMRI: intraoperative MRI; MEG: magnetoencephalography; PET: positron emission tomography; SPECT: single photon emission computed tomography; 3D: three-dimensional.
癫痫手术中电极植入的主要障碍之一是从植入到取出期间电极发生移位。我们使用术中磁共振成像（iopMRI）数据和CT/MRI重建来评估这种可能的电极移位情况。
对13例耐药性癫痫患者（9例女性，4例男性，中位年龄26±9.4岁）进行检查。植入后，通过3.0T-MRI和薄层CT进行三维重建以评估硬膜下电极的位置。采用容积再现技术对电极进行定位。将植入后和取出前的1.5T-iopMRI扫描与三维重建进行配准，以确定电极移位的程度。
取出时的术中磁共振成像显示1例患者（8%）电极发生了10mm的明显移位。电极移位的中位数为1.7±2.6mm，配准误差为1.9±0.7mm。神经导航系统的中位精度为2.2±0.9mm。12例接受切除性手术的患者中有6例无癫痫发作（Engel 1A级，中位随访时间37.5±11.8个月）。
使用容积再现技术将取出前和植入后的iopMRI扫描与CT/MRI数据进行比较，可实现电极的精确放置。在1例电极发生明显移位的患者中，由于检测到电极移位，手术入路和范围发生了改变。
ECoG：皮质脑电图；EZ：致痫区；iEEG：侵入性脑电图；iopMRI：术中磁共振成像；MEG：脑磁图；PET：正电子发射断层扫描；SPECT：单光子发射计算机断层扫描；3D：三维
