Abstracts

Rationale: Insular epilepsy has been recognized for several years but surgical treatment for this disease has been limited partly because of the difficulty in describing semiology as well as identifying the electrographic patterns.  With the recent advancements in intracranial EEG monitoring, the electrographic patterns have been described better.   This has paved the way for using LASER ablation as a strategy for management of insula seizures. This study was done to analyze our experience with this group of patients and to define the changes in the evaluation of non-lesional epilepsy and surgical techniques.  Methods: We report a series of cases (n=4) from our center where patients with epilepsy underwent stereo-EEG evaluation followed by LASER ablation. Ages of these patients ranged from 7-46 during the time of LASER ablation, and the cohort included 2 males and 2 female patients.  These patients had a history of seizures lasting between 1--21 years.  The suspected cause of the seizures included trauma, infection or prematurity.  All the patients underwent initial video EEG evaluation in epilepsy monitoring unit where the typical clinical seizures were captured.  In addition, they underwent MRI, SPECT, PET, MEG and Neuropsychological evaluation for localization of the epileptogenic zones.   The cases were discussed in the epilepsy monitoring unit conference and as per the recommendations, patients underwent intracranial monitoring with stereo EEG and/ grid and depth electrodes bilaterally.  Epileptogenic zone was noted to be located around the insular regions based on the intracranial EEG monitoring. Results: During the series the surgical procedure performed evolved toward incorporating more techniques of stereo-EEG rather than grids and depth electrodes.  At least two depth electrodes with 5-10 contacts were placed on each insular region.  Insular LASER ablation was planned based on the electrode contacts showing epileptic activity.  Three patients underwent left Insular LASER ablation and one had right insular ablation.  No major complications causing permanent neurological deficits were encountered during this procedure. Conclusions: Our experience suggest that intracranial monitoring can be used as an effective and safe strategy for localizing non-lesional epileptogenic zones in case of insular epilepsy. Also, LASER ablation can an effective surgical management tool for treating these group of patients. Funding: None