Abstracts

Rationale: Epilepsy involving insula and cingulate regions have 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 in identifying the electrographic patterns. In addition, accessibility of these regions for surgical management had been also a challenge. With the recent advancements in intracranial EEG monitoring, the electrographic patterns have been described better. This has paved the way for using Laser Interstitial Thermal Therapy (LITT) as a strategy for management of insula seizures. We report the experience in our center on stereo EEG and subsequent laser ablation in patients having epilepsy in insular/cingulate regions. Methods: Fourteen patients in our center with intractable epilepsy underwent stereoEEG evaluation followed by LASER ablation (LA). Ages of these patients ranged from 6-47 years at the time of LA, and included 5 males and 9 female patients. These patients had a onset of seizures between 3 weeks -39 years. The suspected cause of the seizures included trauma, infection or prematurity. All the patients underwent 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. Patients who were noted to have epileptogenic zone in insula or cingulate cortex underwent LA. Results: The number of insular contacts ranged from 6-28 and cingulate contacts ranged between 12-24. Electrode related bleeding was noted in 3 of the 14 cases. No neurological deficits were associated with electrode placement. Among the patients who underwent insular LA, who were followed between 3 months to 15 months, 2 patients had ILAE class 1 outcome. 2 patients had ILAE class 2 outcome. 6 patients had ILAE class 3 outcome and 1 patient had ILAE class 4 outcome. The patient who underwent both insula and cingulate ablation had Class 1 outcome. Among the 3 patients who had cingulate LA, 2 patients achieved ILAE class 1 outcome. One of the patients had ILAE class 3 outcome, with > 90 % seizure reduction. Conclusions: Our experience suggests that intracranial monitoring can be used as an effective strategy for localizing non-lesional epileptogenic zones in case of insular/ cingulate epilepsy. Also, LA can be an effective surgical management tool for treating these patients. Funding: No funding