Authors :
Presenting Author: Mohammad Taba, MD – Division of Adult Neurology, Ronald Reagan Hospital, David Geffen School of Medicine
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
Aria Fallah, MD, MSc, MBA – Department of Neurosurgery, UCLA Medical Center, David Geffen School of Medicine
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
Dawn Eliashiv, MD – David Geffen School of Medicine at UCLA
Rationale:
For patients with drug-resistant epilepsy (DRE), surgical intervention may not be viable when seizures originate from multiple foci or eloquent brain regions. In such scenarios, neuromodulation represents a promising alternative. Studies have shown that responsive neurostimulation (RNS) targeting various thalamic nuclei can be effective in treating multifocal or generalized epilepsy. However, the indications and outcomes of corticothalamic RNS placement are still under investigation.
Methods:
We retrospectively reviewed eight patients (both adults and pediatric) who underwent corticothalamic RNS placement between 2022 and 2024 at a single level 4 epilepsy center: UCLA Ronald Reagan Medical Center and Mattel Children’s Hospital. RNS placement was performed either as a primary intervention or as a revision following original cortical RNS placement. Clinical data were collected retrospectively from electronic medical records (EMR) and the NeuroPace PDMS system.
Results:
The cohort consisted of six male and two female patients, including five pediatric and three adult individuals. At the time of surgery, patient ages ranged from 4 to 28 years (median age: 15.5 years). All patients had at least one year of follow-up (range: 13 to 39 months), except for one patient whose electrodes were removed two months post-implantation due to infection. In six patients, the centromedian (CM) nucleus was targeted, while in two patients the pulvinar nucleus was the chosen target. Three patients already had cortical RNS placement and thalamic electrode was either switched to or later added as a new electrode. Five patients out of eight in our case series showed more than 50% reduction in seizure frequency. A summary of the indications and outcomes of corticothalamic RNS placement is provided in the accompanying table.
Conclusions:
Corticothalamic RNS may be a viable option for patients with broad hemispheric epilepsy or those whose seizures originate from multiple foci within one hemisphere. Bilateral corticothalamic RNS can also be considered in patients with bihemispheric multifocal epilepsy. While the centromedian (CM) nucleus has shown promise as a target for frontal or peri-Rolandic epilepsy, the pulvinar nucleus may be more suitable for occipital or posterior parietal epilepsy. Early seizure propagation to the centromedian (CM) or pulvinar nucleus observed during intracranial monitoring may serve as an additional indication for selecting these nuclei as RNS targets.
Funding: No funding was received. Dr. Eliashiv who is a senior co-author on this abstract, receives trial fundings from NeuroPace which is unrelated to this study