A Multi‐Center Retrospective Study of the Clinical Outcomes in Patients Implanted in the Insula with the RNS System
Abstract number :
2.439
Submission category :
4. Clinical Epilepsy / 4C. Clinical Treatments
Year :
2022
Submission ID :
2232919
Source :
www.aesnet.org
Presentation date :
12/4/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:28 AM
Authors :
Patricia Dugan, MD – New York University Grossman School of Medicine; Reya Hayek, MD – Resident, Medicine, New York University Grossman School of Medicine; Helen Han, MD – Faculty, Neurology, Rutgers Health; Jonathon Parker, MD – Neurosurgery – Mayo Clinic Arizona; Jiyeoun Yoo, MD – Associate Professor, Neurology, Mount Sinai Health System; Yuhao Huang, MD – Resident, Neurosurgery, Stanford Medical Center; Casey Halpern, MD – Chief, Stereotactic and Functional Neurosurgery; Associate Professor, Neurosurgery, Penn Medicine; Onome Eka, MBBS, MPH – Clinical Research Coordinator, Mount Sinai Health System; Charlotte Jeffreys, MLS – Clinical Research Coordinator, Neurology, Dartmouth-Hitchcock Medical Center; Dawn Eliashiv, MD – Professor of Neurology; Co-Director of the UCLA Seizure Disorders Center, Neurology, UCLA Medical Center; Barbara Jobst, MD – Chair and Professor of Neurology, Neurology, Dartmouth-Hitchcock Medical Center
This is a Late-Breaking abstract.
Rationale: Due to the risk of morbidity with surgical resection or ablation of the insula, neurostimulation may be a complementary therapeutic option. The efficacy of the Responsive Neurostimulation (RNS) System has been well-established but there is a paucity of published data describing its use specifically for insular epilepsy. This study aims to retrospectively evaluate the surgical approach, efficacy, and safety in patients that were implanted with the RNS System for the treatment of insular epilepsy.
Methods: Patients from participating sites (NYU Langone Health, Darthmouth-Hitchcock Medical Center, Mount Sinai Health System, Stanford Medical Center, UCLA Medical Center) with at least one lead in the insula &/or operculum connected to RNS were included. Medical records were reviewed through August 31, 2020. Data regarding demographics, epilepsy history, and safety data were abstracted; seizure frequency prior to RNS implantation, 1 and 2 years post-implantation, and at last follow up was assessed.
Results: Thirty patients (15/30, 50.0% male) from 5 participating sites were included. In addition to an insular lead, 9 (30.0%) had a lead in the frontal lobe, 8 (26.67%) in the neocortical temporal lobe, 3 (10.0%) in the hippocampus, 3 (10.0%) in the parietal lobe, and 2 (6.67%) in the occipital lobe. Five (16.67%) had a pair of depth electrodes within the insula. All underwent intracranial EEG (IEEG) monitoring prior to RNS placement; 9 (30%) had suspected insular involvement without clear onsets within the insula, 17 (56.67%) had multifocal onsets that included the insula, and 4 (13.33%) had insular or opercular onsets. Sixteen (53.33%) had abnormal brain MRIs prior to RNS placement that showed remote neurosurgery (10/30, 20.0%), malformations of cortical development (4/30, 13.33%), posttraumatic encephalomalacia (1/30, 3.33%) or stroke (1/30, 3.33%). Fourteen (46.67%) had prior resections and 7 (23.33%) had prior vagus nerve stimulator placement. Nineteen (63.33%) had data on surgical trajectory; all insular RNS leads were implanted with an oblique surgical approach. Four (13.33%) had seizure exacerbation 2.25 (mean) years after implantation and therapy titration. Two (6.67%) had after-discharges and 1 (3.33%) had limb paresthesia after increasing current in the insular lead. Serious adverse events occurred late (mean 3 years), including infection (2/30, 6.67%) and prolonged hospitalization (1/30, 3.33%). Majority showed improvement in terms of clinical global improvement at last follow up with 12 (40.0%) very much improved, 8 (26.67%) much improved, and 5 (16.67%) with minimal improvement. Of the 9 patients with insular RNS leads despite lack of clear IEEG localization in the insula, 7 (7/9, 77.78%) reported improvement in seizure frequency.
Conclusions: The treatment of insular epilepsy with the RNS is relatively safe & may provide meaningful seizure reduction in a diverse cohort of epilepsy patients with insular involvement. These findings highlight significant RNS therapy titration considerations that warrant further investigation, and emphasizes the role of the insular cortex in seizure networks.
Funding: None
Clinical Epilepsy