Electrographic seizures during low-current thalamic deep brain stimulation in mice.

Background: Deep brain stimulation of the central thalamus (CT-DBS) has potential for modulating states of consciousness, but it can also trigger electrographic seizures, including poly-spike-wave trains (PSWT).
Objectives: To report the probability of inducing PSWTs during CT-DBS in awake, freely-moving mice.
Methods: Mice were implanted with electrodes to deliver unilateral and bilateral CT-DBS at different frequencies while recording electroencephalogram (EEG). We titrated stimulation current by gradually increasing it at each frequency until a PSWT appeared. Subsequent stimulations to test arousal modulation were performed at the current one step below the current that caused a PSWT during titration.
Results: In 2.21% of the test stimulations (10 out of 12 mice), CT-DBS caused PSWTs at currents lower than the titrated current, including currents as low as 20 μA.
Conclusion: Our study found a small but significant probability of inducing PSWTs even after titration and at relatively low currents. EEG should be closely monitored for electrographic seizures when performing CT-DBS in both research and clinical settings.
Competing Interests: Declaration of competing interest Emery N. Brown holds patents on anesthetic state monitoring and control; holds founding interest in PASCALL, a start-up developing physiological monitoring systems; receives royalties from intellectual property through Massachusetts General Hospital licensed to Masimo. The interests of Emery N. Brown were reviewed and are managed by Massachusetts General Hospital and Mass General Brigham in accordance with their conflict of interest policies. The rest of the authors do not have any interest to report.
(Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)