Authors :
Presenting Author: Eric Ronne, MD – Division of Pediatric Neurology, Department of Pediatrics, UCLA Mattel Children's Hospital, David Geffen School of Medicine
Samuel S. Ahn, MD – UCLA
Sotaro Kanai, MD, PhD – Division of Pediatric Neurology, Department of Pediatrics, David Geffen School of Medicine at the University of California, Los Angeles, California, USA
Mohammad Tabaeizadeh Fesharaki, MD – UCLA
Aria Fallah, MD, MSc, MBA – Department of Neurosurgery, UCLA Medical Center, David Geffen School of Medicine
Ausuf Bari, MD, PhD – UCLA
Dawn Eliashiv, MD – David Geffen School of Medicine at UCLA
Hiroki Nariai, MD, PhD, MS – Department of Pediatrics, Division of Pediatric Neurology, David Geffen School of Medicine at the University of California, Los Angeles, California, USA
Rationale:
Bilateral tonic-clonic (BTC) seizures are associated with increased morbidity and mortality in patients with medically refractory epilepsy, and adequate control of these seizures is therefore critically important in improving outcomes. Neuromodulation therapies targeting the thalamus, such as responsive neurostimulation (RNS), have become increasingly utilized surgical options in patients with drug-resistant generalized-onset and focal to BTC seizures (example RNS recording, Figure 1). However, outcome data following bi-thalamic RNS placement are still forthcoming. Here we report a single-center retrospective case series of patients with bilateral tonic-clonic seizures due to idiopathic generalized epilepsy (IGE) or focal/multifocal epilepsy who underwent RNS device implantation targeting the bilateral centromedian nucleus (CM) of the thalamus.Methods:
Patients evaluated at a single level 4 epilepsy center who ultimately received RNS implantation of the bilateral CM were retrospectively reviewed using electronic medical records and RNS recording data. Patients with BTC seizures due to IGE or focal/multifocal epilepsy were included. Overall seizure burden was assessed at clinic follow up via categorical clinician assessment of seizure frequency and family-reported subjective seizure severity, each as compared to pre-implantation baseline. Additional data including complications were obtained via chart review.Results:
Nine patients were included in the study: 4 with IGE and 5 with focal to bilateral tonic-clonic seizures of various etiologies. The median age at RNS implantation was 22 years (range 19-60 years). The median duration of follow-up from RNS implant was 25 months (range 8-43 months). Three patients had received Vagus Nerve Stimulation (VNS) therapy prior to RNS implant. At most recent follow-up, 7 patients (78%) reported ≥50% reduction in seizure frequency from pre-implant baseline, 1 patient reported some but less than 50% reduction, and 1 patient reported no change in seizure frequency. Four patients reported “much better” subjective seizure severity, while 2 reported “better” and 3 reported “no change” in seizure severity. All patients with IGE reported “better” or “much better” seizure severity at most recent follow up. No surgical-related complications were reported, and no stimulation related side effects were present at most recent follow up.Conclusions:
RNS targeting bilateral CM in patients with IGE and focal to BTC seizures is a safe and feasible therapeutic option. Further analyses of longitudinal seizure response, cognitive outcomes, and quality-of-life measures are needed.Funding:
AF: paid speaker for educational lectures for NeuroPace, Dr. Alfonsina Q. Davies Endowed Chair for Epilepsy Research
AB: receives funding from NeuroPace and Medtronic
DE: National Institute of Neurological Disorders and Stroke (NINDS), receives clinical trial funding from NeuroPace and Medtronic
HN: NINDS, the Sudha Neelakantan & Venky Harinarayan Charitable Fund, the Elsie and Isaac Fogelman Endowment, and the UCLA Children's Discovery and Innovation Institute (CDI) Junior Faculty Career Development Grant