Authors :
Presenting Author: Holly Skinner, DO – Advent Health Orlando
Elakkat Gireesh, MD – Advent Health Orlando
Christina Wombles, ARNP – Advent Health Orlando
JooHee Seo, MD – Advent Health Orlando
Po-Ching Chen, PhD – Advent Health Orlando
Ki Hyeong Lee, MD – Advent Health Orlando
James Baumgartner, MD – Advent Health Orlando
Rationale:
Patients with drug-resistant, poorly localized epilepsy (PLE) and drop seizures often have limited surgical options due to rapid interhemispheric seizure spread via the corpus callosum. Corpus callosotomy (CC) is frequently performed to interrupt this propagation. Postoperative EEG patterns may become more localized, enabling curative interventions in some cases. However, others continue to have diffuse or non-localizable seizures. Prior case series suggest that responsive neurostimulation (RNS) targeting the centromedian nucleus (CMN) of the thalamus can reduce seizure burden in generalized epilepsies and epileptic encephalopathies. The clinical course and safety of CMN RNS following CC remain poorly described. This retrospective series evaluates seizure outcomes and complications of CMN RNS in post-CC patients.
Methods:
Data was collected through retrospective review of 7 patients’ medical record and Neuropace® Patient Data Management System data.
Results:
Seven patients (6 male) with mean age 18.1 years underwent CC between 2014–2022 and CMN RNS between 2022–2023. Mean epilepsy duration was 17.3 years. A genetic etiology was confirmed in 4 and suspected in the remaining 3. After CC, 4 of 7 patients (57%) experienced seizure improvement, including 3 (43%) with ≥50% reduction. Among these CC responders, 2 achieved an additional ≥50% reduction with CMN RNS. Notably, 2 of 3 CC non-responders also achieved ≥50% seizure reduction after RNS.
In total, 5 of 7 patients (71%) showed benefit following CMN RNS: 4 (57%) had ≥50% seizure reduction; 3 (43%) reported improved seizure severity with elimination of generalized tonic-clonic (GTC) seizures; and 1 (14%) had shorter seizure duration. Three patients (43%) experienced both ≥50% seizure reduction and elimination of GTC seizures. Family-reported quality of life improved in 5 of 7 cases (71%).
No permanent neurological deficits occurred due to CMN RNS. Short-term complications included: one right frontal hemorrhage with transient left hemiparesis (resolved in 22 months), one case of bilateral frontal edema and headache (resolved in 1 month), one episode of fever with suspected VP shunt infection but negative cultures (resolved in 1 month), and one instance of left CMN lead migration causing nystagmus, which resolved after deactivation of stimulation at affected contacts.
Conclusions:
CMN RNS implantation following CC appears safe and may provide meaningful seizure reduction and quality of life improvement in selected patients with drug-resistant PLE. Benefit was observed in both CC responders and non-responders, including those with suspected genetic etiologies.Funding: none