Uncovering Spatiotemporal Dynamics of the Corticothalamic Network during Seizures

Abstract

ABSTRACTObjectiveAlthough the clinical efficacy of deep brain stimulation targeting the anterior nucleus (AN) and centromedian nucleus (CM) of the thalamus has been actively investigated for the treatment of medication-resistant epilepsy, few studies have investigated dynamic ictal changes in corticothalamic connectivity in human EEG recording. This study aims to establish the complex spatiotemporal dynamics of the ictal corticothalamic network associated with various seizure foci.MethodsWe analyzed ten patients (aged 2.7–28.1) with medication-resistant focal epilepsy who underwent stereotactic EEG evaluation with thalamic coverage. We examined both undirected and directed connectivity, incorporating coherence and spectral Granger causality analysis (GCA) between the diverse seizure foci and thalamic nuclei (AN and CM).ResultsIn our analysis of 36 seizures, coherence between seizure onset and thalamic nuclei increased across all frequencies, especially in slower bands (delta, theta, alpha). GCA showed increased information flow from seizure onset to the thalamus across all frequency bands, but outflows from the thalamus were mainly in slower frequencies, particularly delta. In the subgroup analysis based on various seizure foci, the delta coherence showed a more pronounced increase at CM than at AN during frontal lobe seizures. Conversely, in limbic seizures, the delta coherence increase was greater at AN compared to CM.InterpretationIt appears that the delta frequency plays a pivotal role in modulating the corticothalamic network during seizures. Our results underscore the significance of comprehending the spatiotemporal dynamics of the corticothalamic network during seizures, and this knowledge could guide personalized neuromodulation treatment strategies.Summary for Social MediaTwitter handles:@saarang_p; @BillSpeierWhat is the current knowledge on the topicAlthough the clinical efficacy of deep brain stimulation targeting the anterior nucleus and centromedian nucleus of the thalamus has been actively investigated for the treatment of medication-resistant epilepsy, few studies have investigated dynamic ictal changes in corticothalamic connectivity in human EEG recording.What question did this study addressThis study aimed to establish the complex spatiotemporal dynamics of the ictal corticothalamic network associated with various seizure foci.What does this study add to our knowledgeThe delta frequency plays a pivotal role in modulating the corticothalamic network during seizures. There are seizure-onset dependent spatiotemporal dynamics of the ictal corticothalamic network.How might this potentially impact on the practice of neurologyThis knowledge could guide personalized neuromodulation treatment strategies.