Stereotactic Electroencephalography Implantation Through Nonautologous Cranioplasty: Proof of Concept.

BACKGROUND Stereoelectroencephalography (SEEG) is an effective method to define the epileptogenic zone (EZ) in patients with medically intractable epilepsy. Typical placement requires passing and anchoring electrodes through native skull. OBJECTIVE To describe the successful placement of SEEG electrodes in patients without native bone. To the best of our knowledge, the use of SEEG in patients with nonautologous cranioplasties has not been described. METHODS We describe 3 cases in which SEEG was performed through nonautologous cranioplasty. The first is a 30-yr-old male with a titanium mesh cranioplasty following a left pterional craniotomy for aneurysm clipping. The second is a 51-yr-old female who previously underwent lesionectomy of a ganglioglioma with mesh cranioplasty and subsequent recurrence of her seizures. The third is a 31-yr-old male with a polyether ether ketone cranioplasty following decompressive hemicraniectomy for trauma. RESULTS SEEG was performed successfully in all three cases without intraoperative difficulties or complications and with excellent electroencephalogram recording and optimal localization of the seizure focus. The EZ was successfully localized in all three patients. There were no limitations related to drilling or inserting the guiding bolt/electrode through the nonautologous cranioplasties. CONCLUSION SEEG through nonautologous cranioplasties was clinically feasible, safe, and effective in our series. The presence of nonautologous bone cranioplasty should not preclude such patients from undergoing SEEG explorations.