Abstracts

Safety and Efficacy of Brain-responsive Neurostimulation Treatment with Depth Leads Placed in the Neocortex

Abstract number : 3.231
Submission category : 4. Clinical Epilepsy / 4C. Clinical Treatments
Year : 2022
Submission ID : 2205016
Source : www.aesnet.org
Presentation date : 12/5/2022 12:00:00 PM
Published date : Nov 22, 2022, 05:27 AM

Authors :
Sina Sadeghzadeh, AB – Stanford University School of Medicine; David Purger, MD, PhD – Stanford University; Emily Mirro, BS – NeuroPace Inc; Ioannis Karakis, MD, PhD – Emory University School of Medicine; Robert Gross, MD, PhD – Emory University School of Medicine; Chengyuan Wu, MD – Thomas Jefferson University; Cornelia Drees, MD – University of Colorado Hospital, Mayo Clinic Arizona; Ahmed Raslan, MD – Oregon Health & Science University; Caleb Nerison, BA, BS – Oregon Health & Science University; Lia Ernst, MD – Oregon Health & Science University; Michael Sather, MD – Penn State Health Milton S Hershey Medical Center; Barbara Jobst, MD – Dartmouth Health University; Josh Aronson, MD – Dartmouth Health University; Jonathan Parker, MD, PhD – Stanford University; Casey Halpern, MD – University of Pennsylvania

Rationale: The RNS System is efficacious in treating drug resistant epilepsy (DRE) arising from neocortical foci.1 During clinical trials, a majority of patients with neocortical seizure foci received cortical strip leads, perhaps due to intracranial monitoring with subdural grid/strips. Stereo-EEG (SEEG) has become more widely utilized since the trials, resulting in placement of neocortical RNS System depth leads.  This is also an appealing approach when dural adhesions make strip lead implantation difficult.  We report on patients treated with the RNS System with depth leads in the neocortex at 7 institutions.

Methods: This was a retrospective chart review study of adult patients with drug-resistant focal epilepsy who underwent placement and connection of at least one RNS System depth lead in the neocortex. Median percentage reduction in clinical seizure frequency at 1 year and at last follow-up as compared to pre-RNS System was calculated for all patients. Demographics and safety data were obtained.

Results: There were 61 neocortical depth leads connected to the RNS neurostimulator in 53 patients. Some patients (n=33) also had additional depth leads in a non-neocortical focus, or an additional neocortical strip lead (n=12). The location of the neocortical depth lead (Figure 1) and patient demographics (Table 1) were obtained. The median follow-up was 2.2 years (range, 0.4-5.2 years). The median % reduction in clinical seizures at 1 year was 63% and 75% at last follow-up. Twelve patients (23%) were seizure free at last follow-up, a majority of these (83%) were seizure free for > 6 months and 5 patients for > 1 year._x000D_  _x000D_ There were 2 (3.8%) scalp infections. One patient (1.9%) had each of the following:  Chemical meningitis, epidural hematoma, post-surgical status epilepticus (resolved with stimulation), new-onset non-epileptic seizures, and a stim-related side effect of nausea (resolved with programming).

Conclusions: This multicenter series of 53 patients with RNS System depth leads placed in the neocortex demonstrated a 75% median reduction in seizures at 2 years of follow-up.  The surgical safety is consistent with placement of deep brain electrodes for movement disorders.2 Neocortical depth leads may be preferred with the RNS System following SEEG evaluation and/or if strip placement poses increased surgical risk.3
_x000D_ References:_x000D_ 1. Jobst B, et al. Epilepsia. 2017_x000D_ 2. Engel K, et al. PLoS One. 2018_x000D_ 3. Miller KJ, et al. Seizure. 2015

Funding: Not applicable
Clinical Epilepsy