A Frameless Stereotactic Implantation Technique for Depth Electrodes in Refractory Epilepsy Using Intraoperative Magnetic Resonance Imaging.

Various complex techniques for depth electrode insertion in refractory epilepsy using preoperative imaging have been investigated. We evaluated a simple, accurate, cost-effective, and timesaving method using intraoperative magnetic resonance imaging (MRI). A neuronavigation-guided insertion tube attached to bone facilitated the placement of stereotactic percutaneous drill holes, bolt implantation, and frameless stereotactic insertion of depth electrodes. Image registration was carried out by head coil fiducials with trajectory planning and intraoperative electrode correction. In 6 patients with refractory epilepsy (3 women and 3 men; mean age, 30.0 years; range, 20-37 years), 58 depth electrodes (9-11 per patient) were placed. The mean length of the inserted electrodes was 37.3 mm ± 8.8 (mean ± SD) (range, 22.1-84.4 mm). The overall target point accuracy was 3.2 mm ± 2.2 (range, 0-8.6 mm), which was significantly different from the overall entry point accuracy of 1.4 mm ± 1.2 (P < 0.0001). All electrodes functioned perfectly, enabling high-quality stereo-electroencephalography recordings over a period of 7.3 days ± 0.5 (range, 7-8 days). The mean implantation time for 9-11 electrodes per patient was 115 minutes ± 36.3 (range, 75-160 minutes; 12 minutes for 1 electrode on average) including the intraoperative MRI (T1 three-dimensional magnetization-prepared rapid acquisition gradient echo, T2, and diffusion tensor imaging). There was no hemorrhage, infection, or neurologic deficit related to the procedure. Our frameless technique of depth electrode insertion using intraoperative MRI guidance is an accurate, reliable, cost-effective, and timesaving method for stereo-electroencephalography.

Roessler K ，Sommer B ，Merkel A ，Rampp S ，Gollwitzer S ，Hamer HM ，Buchfelder M ... -  《-》

A novel miniature robotic device for frameless implantation of depth electrodes in refractory epilepsy.

Dorfer C ，Minchev G ，Czech T ，Stefanits H ，Feucht M ，Pataraia E ，Baumgartner C ，Kronreif G ，Wolfsberger S ... -  《-》

Intraoperative computed tomography for intracranial electrode implantation surgery in medically refractory epilepsy.

Lee DJ ，Zwienenberg-Lee M ，Seyal M ，Shahlaie K ... -  《-》

Frameless stereotactic drilling for placement of depth electrodes in refractory epilepsy: operative technique and initial experience.

Dorfer C ，Stefanits H ，Pataraia E ，Wolfsberger S ，Feucht M ，Baumgartner C ，Czech T ... -  《-》

In Vivo Accuracy of a Frameless Stereotactic Drilling Technique for Diagnostic Biopsies and Stereoelectroencephalography Depth Electrodes.

Accurate frameless neuronavigation is highly important in cranial neurosurgery. The accuracy demonstrated in phantom models might not be representative for results in patients. Few studies describe the in vivo quantitative accuracy of neuronavigation in patients. The use of a frameless stereotactic drilling technique for stereoelectroencephalography depth electrode implantation in epilepsy patients, as well as diagnostic biopsies, provides a unique opportunity to assess the accuracy with postoperative imaging of preoperatively planned trajectories. In 7 patients with refractory epilepsy, 89 depth electrodes were implanted using a frameless stereotactic drilling technique. Each electrode was planned on a preoperative magnetic resonance and computed tomographic scan, and verified on postoperative computed tomographic scan. After fusion of preoperative and postoperative imaging, the accuracy for each electrode was calculated as the Euclidean distance between the planned and observed position of the electrode tip. The median Euclidean distance between planned and observed electrode implantations was 3.5 mm (95% confidence interval, 2.9-3.9 mm) with a range of 1.2-13.7 mm. In this study, we showed that the in vivo accuracy of our frameless stereotactic drilling technique, suitable for stereoelectroencephalography depth electrode placement and diagnostic brain biopsies, was 3.5 mm.

Verburg N ，Baayen JC ，Idema S ，Klitsie MA ，Claus S ，de Jonge CS ，Vandertop WP ，de Witt Hamer PC ... -  《-》