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Updated: Apr 26, 2026
Stereo-Electro-Encephalo-Graphy SEEG With Robotic Assistance in the Presurgical Evaluation of Medical Refractory Epilepsy: A Technical Note
Published on: June 13, 2016
Frameless stereotactic drilling for placement of depth electrodes in refractory epilepsy: operative technique and
Christian Dorfer1, Harald Stefanits, Ekaterina Pataraia
1*Departments of Neurosurgery, ‡Pediatrics and Adolescence Medicine, and §Neurology, Medical University of Vienna, Vienna, Austria; ¶2nd Neurological Department, General Hospital Hietzing, Vienna, Austria.
Background:
For stereotactic implantation of depth electrodes in refractory epilepsy, both frame-based and frameless techniques have been developed. The higher versatility of current frameless techniques compared with framed-based methods is paid by the need of a standard burr hole for the implantation of 1 electrode.
Objective:
To develop a frameless method that allows convenient implantation of the electrode via a percutaneous bolt as used in frame-based methods, thereby avoiding the need for a standard burr hole.
Methods:
We adopted our technique from frameless stereotactic biopsy and designed the GIDE, a bone-fixated Guide for Implantation of Depth Electrodes. This reducing sleeve works as a stabilizer of the neuronavigation arm through bony contact and allows percutaneous stereotactic drilling, screwing of an implantation bolt, and placement of the depth electrode.
Results:
Twenty-six electrodes in 7 patients (5 male and 2 female patients; median age, 19.6 years; range, 5.5-39.1 years) were successfully implanted. The overall accuracy was comparable to that of frameless stereotactic biopsy with a target deviation of 3.0±1.9 mm (mean±SD). All electrodes were within or touched the targeted anatomic structure with an adequate quality of the recordings. We encountered no hemorrhage or neurological deficit related to the depth electrode.
Conclusion:
Our technique combines the high versatility of frameless stereotaxy with the convenient implantation and fixation of the depth electrode via a percutaneous bolt used in frame-based stereotactic methods. Thus, our technique allows fast, efficient implantation of depth electrodes for intracranial electroencephalography recordings.
