How deep brain stimulation modulates cortical epileptic dynamics — Insights from computational modeling

Despite the growing scientific evidence that supports the efficacy of deep brain stimulation (DBS) for controlling epileptic seizure dynamics, further research remains mandatory to optimize DBS parameters for an efficient clinical use. In particular, progress can be expected from detailed study of the still poorly understood mechanisms that are responsible for the modulation of neural activity by DBS. In this work, a computational model of the thalamocortical loop was developed to explore the mechanisms of thalamic DBS and its effects on cortical dynamics. The model was tuned using real intracerebral EEG (iEEG) signals recorded in an epileptic patient. Results confirmed the dependence of DBS activated mechanisms on the choice of stimulation frequency. They revealed that short-term depression, feed-forward inhibition, and stimulation-induced depolarization of inhibitory reticular neurons seem to be key factors of frequency-dependent effects.