Objective:

This retrospective study aims to compare seizure freedom and adverse events associated with Centro-median (CM) thalamic nucleus stimulation by DBS vs RNS device. 

Background:

Deep brain stimulation (DBS) and responsive nerve stimulation (RNS) are evolving treatment modalities for refractory epilepsy. Both DBS and RNS are increasingly being placed at various anatomical sites, including the Centro-median (CM) thalamic nucleus. Research is currently limited on efficacy and adverse outcomes of CM nucleus DBS and RNS stimulation.

Design/Methods:

A retrospective analysis was performed on our cohort of 10 refractory epilepsy cases who underwent RNS and DBS placement over the CM thalamic nucleus. Data was collected from chart review. Seizure frequency reduction was based on reports by patient or caretaker, with >50% reduction in disabling seizure frequency considered significant reduction. 

Results:

Out of ten refractory epilepsy cases, half of patients had CM thalamic nucleus stimulation with DBS (80% male) and half with RNS (60% male) device. Mean seizure duration for DBS patients was 20.8 years compared to RNS patients at 25.2 years.  In the DBS cohort, 40% of patients had refractory generalized epilepsy, 40% multifocal epilepsy, 20% focal epilepsy. 100% of RNS patients had refractory generalized epilepsy. The significant seizure reduction rate for both DBS and RNS stimulation was 80%. One RNS patient achieved total seizure freedom over 12 months, and one multifocal epilepsy patient with DBS had 100% generalized epilepsy freedom for 15 months but continued to have focal nondisabling seizures. One RNS patient required reimplantation due to post-operative infection. One DBS patient reported significant mania and one reported sensory changes with faster stim parameter changes.  

Conclusions:

Both Centro-median DBS and RNS showed 80% of patients with significant seizure reduction (>50% from baseline). Based on this data, Centro-median DBS and RNS have roughly equivalent efficacy in the treatment of refractory epilepsy, without significant difference in adverse outcomes.