A multicenter retrospective study of patients treated in the thalamus with responsive neurostimulation

Madeline C Fields; Onome Eka; Cristina Schreckinger; Patricia Dugan; Wael F Asaad; Andrew S Blum; Katie Bullinger; Jon T Willie; David E Burdette; Christopher Anderson; Imran H Quraishi; Jason Gerrard; Anuradha Singh; Kyusang Lee; Ji Yeoun Yoo; Saadi Ghatan; Fedor Panov; Lara V Marcuse

doi:10.3389/fneur.2023.1202631

A multicenter retrospective study of patients treated in the thalamus with responsive neurostimulation

Front Neurol. 2023 Sep 8:14:1202631. doi: 10.3389/fneur.2023.1202631. eCollection 2023.

Authors

Madeline C Fields¹, Onome Eka¹, Cristina Schreckinger², Patricia Dugan³, Wael F Asaad⁴, Andrew S Blum⁵, Katie Bullinger⁶, Jon T Willie⁷, David E Burdette⁸, Christopher Anderson⁹, Imran H Quraishi¹⁰, Jason Gerrard¹¹, Anuradha Singh¹, Kyusang Lee¹, Ji Yeoun Yoo¹, Saadi Ghatan¹², Fedor Panov¹², Lara V Marcuse¹

Affiliations

¹ Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY, United States.
² St. Mary's Health Care System, Athens, GA, United States.
³ Department of Neurology, Langone Medical Center, New York University, New York, NY, United States.
⁴ Department of Neurosurgery, Warren Alpert Medical School, Brown University, Providence, RI, United States.
⁵ Department of Neurology, Warren Alpert Medical School, Brown University, Providence, RI, United States.
⁶ Department of Neurology, School of Medicine, Emory University, Atlanta, GA, United States.
⁷ Department of Neurosurgery, School of Medicine, Washington University in St Louis, St. Louis, MO, United States.
⁸ Department of Neurosciences, Corewell Health, Grand Rapids, MI, United States.
⁹ Department of Neurology, Medical College of Wisconsin, Milwaukee, WI, United States.
¹⁰ Department of Neurology, School of Medicine, Yale University, New Haven, CT, United States.
¹¹ Department of Neurosurgery, School of Medicine, Yale University, New Haven, CT, United States.
¹² Department of Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, NY, United States.

Abstract

Introduction: For drug resistant epilepsy patients who are either not candidates for resective surgery or have already failed resective surgery, neuromodulation is a promising option. Neuromodulatory approaches include responsive neurostimulation (RNS), deep brain stimulation (DBS), and vagal nerve stimulation (VNS). Thalamocortical circuits are involved in both generalized and focal onset seizures. This paper explores the use of RNS in the centromedian nucleus of the thalamus (CMN) and in the anterior thalamic nucleus (ANT) of patients with drug resistant epilepsy.

Methods: This is a retrospective multicenter study from seven different epilepsy centers in the United States. Patients that had unilateral or bilateral thalamic RNS leads implanted in the CMN or ANT for at least 6 months were included. Primary objectives were to describe the implant location and determine changes in the frequency of disabling seizures at 6 months, 1 year, 2 years, and > 2 years. Secondary objectives included documenting seizure free periods, anti-seizure medication regimen changes, stimulation side effects, and serious adverse events. In addition, the global clinical impression scale was completed.

Results: Twelve patients had at least one lead placed in the CMN, and 13 had at least one lead placed in the ANT. The median baseline seizure frequency was 15 per month. Overall, the median seizure reduction was 33% at 6 months, 55% at 1 year, 65% at 2 years, and 74% at >2 years. Seizure free intervals of at least 3 months occurred in nine patients. Most patients (60%, 15/25) did not have a change in anti-seizure medications post RNS placement. Two serious adverse events were recorded, one related to RNS implantation. Lastly, overall functioning seemed to improve with 88% showing improvement on the global clinical impression scale.

Discussion: Meaningful seizure reduction was observed in patients who suffer from drug resistant epilepsy with unilateral or bilateral RNS in either the ANT or CMN of the thalamus. Most patients remained on their pre-operative anti-seizure medication regimen. The device was well tolerated with few side effects. There were rare serious adverse events. Most patients showed an improvement in global clinical impression scores.

Keywords: anterior thalamic nucleus; centromedian nucleus of thalamus; drug-resistant epilepsy (DRE); epilepsy surgery; neuromodulation; responsive neurostimulation (RNS).