Dotnet Electrode as a Novel Approach to Explore Epilepsy: Technical Note with Illustrative Cases

Intracranial electroencephalography (iEEG) is utilized to localize the seizure-onset zone (SOZ). However, sampling sites of electrodes for iEEG are limited to partial brain coverage because of the unacceptable trauma of implantation. The limitation may lead to missing the SOZ because of no data beyond sampling sites. The completely seizure-free rates after iEEG are generally less than 50%. To this end, we designed a novel electrode, the Dotnet electrode (DNE), for whole-brain data sampling implanted through the keyhole approach.

This study described 2 cases with intractable epilepsy for surgical evaluations. For accurate SOZ localization, DNEs were implanted. Comprehensive records included preoperative image data, detailed surgical notes, and postoperative outcomes.

In the first patient, 27 DNEs with 256 contacts were successfully implanted to cover the right hemisphere. The patient tolerated 12 days of iEEG monitoring. In the second patient, 63 DNEs with 548 contacts were implanted across the whole-brain surface. The patient tolerated 9 days of iEEG monitoring. No complications occurred after surgery. The iEEG signals were of good quality and stability throughout monitoring. The SOZs were localized and surgically removed. Two patients achieved seizure freedom after surgery.

As a minimally invasive technique, DNEs dramatically increase iEEG data for precise localization of SOZ and improve efficacy. DNEs constitute a significant advancement in iEEG monitoring. Further studies are warranted to verify its safety and efficacy and determine the generalizability of DNE.