Embedding digital chronotherapy into medical devices -- A canine validation for controlling status epilepticus through multi-scale rhythmic brain stimulation
Abstract
Circadian and other physiological rhythms play a key role in both normal homeostasis and disease processes. Such is the case of circadian and infradian seizure patterns observed in epilepsy. In this paper we explore a new implantable stimulator that implements chronotherapy as a feedforward input to supplement both open-loop and closed-loop methods. This integrated algorithm allows for stimulation to be adjusted to the ultradian, circadian and infradian patterns observed in patients through slowly-varying temporal adjustments of stimulation and algorithm sub-components, while also enabling adaption of stimulation based on immediate physiological needs such as a breakthrough seizure or change of posture. Embedded physiological sensors in the stimulator can be used to refine the baseline stimulation circadian pattern as a "digital zeitgeber". This approach is tested on a canine with severe drug-resistant idiopathic generalized epilepsy exhibiting a diurnal pattern correlated with sleep-wake cycles. Prior to implantation, the canine's cluster seizures evolved to status epilepticus (SE) and required emergency pharmacological intervention. The cranially-mounted system was fully-implanted bilaterally into the centromedian nucleus of the thalamus. Using time-based modulation, thalamocortical rhythm-specific tuning of frequency parameters as well as fast-adaptive modes based on activity, the canine experienced no further SE events post-implant as of the time of writing (seven months). Importantly, no significant cluster seizures have been observed either, allowing the reduction of rescue medication. The use of chronotherapy as a feedforward signal to augment adaptive neurostimulators could prove a useful method in conditions where sensitivity to temporal patterns are characteristics of the disease state, providing a novel mechanism for tailoring a more patient-specific therapy approach.
Keywords
Cite
@article{arxiv.2107.02993,
title = {Embedding digital chronotherapy into medical devices -- A canine validation for controlling status epilepticus through multi-scale rhythmic brain stimulation},
author = {Mayela Zamora and Sebastian Meller and Filip Kajin and James J Sermon and Robert Toth and Moaad Benjaber and Derk-Jan Dijk and Rafal Bogacz and Gregory A Worrell and Antonio Valentin and Benoit Duchet and Holger A Volk and Timothy Denison},
journal= {arXiv preprint arXiv:2107.02993},
year = {2021}
}
Comments
6 text pages, 4 main figures, Fig 1 has 4 panels, Fig 2 has 3 panels, Fig 4 has 2 panels. 2 text pages of supplementary material, 1 supplementary figure