Initial Experience of Stereotactic EEG Insertion with Anchor Bolt:Problem Extraction and Improvement of Insertion Accuracy

Abstract

In recent years, stereotactic electroencephalography(SEEG)has been focused on as a new invasive method for epileptic focus detection. Although the covering area of the brain surface is smaller than the invasive estimation with subdural electrodes, SEEG can evaluate foci that are deeply seated, noncontiguous leaves, and/or bilateral hemispheres. In addition, SEEG can capture consecutive changes in seizure activity in three dimensions. Due to the development of neuroimaging, computer-assisted, and robotic surgery technology, SEEG insertion began to be commonly used worldwide. Although the approximate complication rates of SEEG are estimated as 1% to 3%, which is lower than that of subdural electrode implantation, the risks of major complications, such as permanent neurological deficit and death, are equivalent. Therefore, meticulous procedure must be needed. To introduce SEEG for intractable partial epilepsy, we acquired approval from the institutional review board and concurrently imported surgical devices and electrodes from the manufacturer in the United States for two surgical candidates. We safely performed SEEG insertion, focal identification, and brain functional mapping by cortical electrical stimulation in two cases. Insertion was difficult for some electrodes, which could be due to the lack of adequate surgical device and large skull angle. Hopefully, the official installation of SEEG will be planned in the near future. We hereby reported tips and pitfalls of SEEG implantation through our own experience in a single institute.