Seizure Detection and Network Dynamics of Generalized Convulsive Seizures: Towards Rational Designing of Closed-Loop Neuromodulation

Abstract

Objective Studies have demonstrated the utility of closed-loop neuromodulation in treating focal onset seizures. There is an utmost need of neurostimulation therapy for generalized tonic-clonic seizures. The study goals are to map the thalamocortical network dynamics during the generalized convulsive seizures and identify targets for reliable seizure detection. Methods Local field potentials were recorded from bilateral cortex, hippocampi, and centromedian thalami in Sprague-Dawley rats. Pentylenetetrazol was used to induce multiple convulsive seizures. The performances of two automated seizure detection methods (line length and P-operators) as a function of different cortical and subcortical structures were estimated. Multiple linear correlations-Granger's Causality was used to determine the effective connectivity. Results Of the 29 generalized tonic-clonic seizures analyzed, line length detected 100% of seizures in all the channels while the P-operator detected only 35% of seizures. The detection latencies were shortest in the thalamus in comparison to the cortex. There was a decrease in amplitude correlation within the thalamocortical network during the seizure, and flow of information was decreased from thalamus to hippocampal-parietal nodes. Significance The preclinical study confirms thalamus as a superior target for automated detection of generalized seizures and modulation of synchrony to increase coupling may be a strategy to abate seizures.

A universal automated tool for reliable detection of seizures in rodent models of acquired and genetic epilepsy

“…Seizure detection algorithms have been described in the literature, 23,24 most of which are aimed at human EEG analysis; very few are designed particularly for rodents. [25][26][27][28][29][30][31][32][33][34] However, no method has been described to detect all of the seizures in different animal models.…”

Novel Optogenetic Approaches in Epilepsy Research

“…Furthermore, the human brain is much larger than that of rodents, which means much more powerful light sources are required to access deep brain structures (Couzin and Kaiser, 2005; Delbeke et al, 2017). Furthermore, optogenetic seizure interruption requires highly accurate real-time seizure detection, which is still a largely unsolved issue (Dheer et al, 2017). Nonetheless, there are several avenues for anti-epileptic optogenetic intervention in humans.…”