Seizure control during spontaneous battery failure with responsive neurostimulation

Objective: We examined seizure control during spontaneous responsive neurostimulation (RNS) battery failure to investigate the persistent benefits of RNS in the absence of neurostimulation. We hypothesized that the loss of direct RNS does not immediately result in seizure worsening.

Methods: Patients with RNS battery failure between August 2019 and December 2020 at a single institution were studied. During periods of battery depletion, the RNS device does not store any electrocorticography records, so we used a telephone-based survey and chart review to assess seizure control during battery depletion.

Results: Eight of 10 eligible participants responded to the survey, with a mean duration of battery failure of 36 days (range: 10-219 days). During battery depletion, one patient reported decreased seizures and five reported no changes in seizure frequency. Only two patients reported increased seizure frequency.

Significance: The benefits of RNS treatment may outlast the immediate effects of direct neurostimulation, lending support to the notion of persistent neuroplasticity. Larger studies should confirm our preliminary findings.