Authors :
Presenting Author: Natasha Llanes, MD – Univeristy of South Florida
Marina Azevedo, BSc – Senior Clinical Research Associate, Neurology, University of South Florida; Kimberly Corso, BSc – Medical Assistant, Neurology, University of South Florida; Yarema Bezchlibnyk, MD, PhD – Assistant Professor, Department of Neurosurgery and Brain Repair, University of South Florida; Ushtar Amin, MD – Assistant Professor, Neurology, University of South Florida; Angelica Rivera-Cruz, MD – Assistant Professor, Neurology, University of South Florida; Selim Benbadis, MD – Division Director, Professor, Neurology, Univeristy of South Florida
Rationale:
The currently FDA-approved neurostimulation devices are: vagus nerve stimulation (VNS), brain-responsive neurostimulation (RNS), and deep brain stimulation (DBS); approved in 1997, 2013 and 2018 respectively. We report a series of refractory epilepsy patients with combined neurostimulation modalities. Methods:
We retrospectively reviewed patients with two or more neurostimulation modalities in our epilepsy center from 2017 to 2023. . Results:
Group 1: VNS+RNS (n=12, 11 after 1 had RNS removed)
- Epilepsy diagnoses were: bitemporal epilepsy (7), unlocalizable focal epilepsy (1, implant in bilateral anterior nucleus of the thalamus and right mesial temporal RNS), left temporal lobe epilepsy (1), Lennox Gastaut syndrome (LGS) (1, implant in bilateral centromedian nucleus of the thalamus and right parietal RNS), right frontal lobe epilepsy (1), left parietal/insular epilepsy (1).
- Chronology of implants: All 12 patients had VNS placed before RNS. The time between VNS and RNS placement ranged from one to 17 years with an average of 7.25 years.
- Five patients had resective surgery: one patient had resective surgery prior to VNS+RNS, one patient had resective surgery, then VNS, a second resective surgery, followed by RNS, and three patients had VNS, followed by surgery, then RNS.
- VNS was kept on after RNS in eight patients, disabled in three patients, and removed in one.
- Seizure outcome after RNS compared to just VNS: Three patients reported GTC freedom, nine patients reported a reduction in GTCs frequency, and one patient reported unchanged seizure frequency.
Group 2: VNS+DBS (n=7)
- Epilepsy diagnoses: left frontal/opercular epilepsy (1), left frontotemporal epilepsy (1), left frontal lobe epilepsy (1), generalized vs bifrontal epilepsy (1), LGS (1), bifrontal epilepsy (1), bitemporal lobe epilepsy (1).
- Chronology of implants: Five patients had DBS placed after VNS and two patients had DBS placed before VNS. The time between the first and the second modality ranged from one to 24 years, with an average of 7.42 years.
- Two patients had resective surgery, both between VNS and DBS.
- VNS was kept on after DBS in six patients and disabled in one.
- Seizure outcome after DBS preceding VNS placement: One patient reported reduction in daily seizures. One patient reported GTC freedom with DBS and reduction in auras after VNS.
- Seizure outcome after VNS preceding DBS placement: Three patients reported reduction in GTC frequency. Two patients reported unchanged seizure frequency.
Group 3: No patients had RNS+DBS
Conclusions:
Although this study is a small population, it appears that both combinations of VNS+RNS and VNS+DBS can provide further improvement in seizure control versus a single modality.
Funding:
N/A