Bilateral Responsive Neurostimulation Targeting Bilateral Periventricular Nodular Heterotopia and Pulvinar Thalamus in Drug-Resistant Epilepsy
Abstract number :
3.396
Submission category :
9. Surgery / 9A. Adult
Year :
2025
Submission ID :
908
Source :
www.aesnet.org
Presentation date :
12/8/2025 12:00:00 AM
Published date :
Authors :
Presenting Author: Muhammad Usman Khalid, MD – University of Kentucky
Farhan Mirza, MD, FAANS – University of Kentucky
Rationale: Periventricular nodular heterotopia (PVNH) is a malformation of cortical development often associated with drug-resistant epilepsy (DRE). Surgical intervention is frequently precluded by bilateral and multifocal epileptogenic zones, particularly when involving deep structures such as the thalamus. Responsive neurostimulation (RNS) offers a tailored approach to seizure management in non-resectable cases. We present a unique case utilizing two separate RNS systems to independently target bilateral PVNH and pulvinar thalamic nuclei in a patient with multifocal, bihemispheric epilepsy.
Methods: A 41-year-old male with longstanding DRE and MRI evidence of bilateral PVNH underwent comprehensive pre-surgical evaluation. Stereo-EEG monitoring confirmed independent seizure onsets from bilateral PVNH with rapid propagation involving pulvinar thalamic regions. Given the multifocal and bilateral nature of the epileptogenic network, the patient was not a candidate for resective surgery. Instead, two RNS neurostimulators were implanted, each connected to two depth electrodes: one targeting PVNH and the other targeting the pulvinar nucleus on the same hemisphere. Electrode placement was confirmed via post-operative imaging. Seizure frequency, electrographic recordings, and patient-reported outcomes were tracked for 36 months post-implantation.
Results: Thirty-six months after implantation, the patient reported a substantial reduction in seizure frequency, with significant improvement in seizure severity and post-ictal recovery. Electrocorticographic data from both RNS systems demonstrated independent seizure activity arising from each PVNH region, often followed by engagement of the ipsilateral pulvinar, supporting its role in propagation. Stimulation was well tolerated, and no device-related complications occurred. The patient also reported subjective improvements in mood and cognition.
Conclusions: This case illustrates the feasibility and clinical benefit of bilateral RNS systems targeting both PVNH and pulvinar nuclei in complex, multifocal epilepsy. Pulvinar stimulation may contribute to modulation of thalamocortical seizure networks.
Funding: This study received no external or industry funding.
Surgery