Assessing the degree of cortical dislamination through electrical pattern analysis

Abstract

Focal cortical dysplasia (FCD) is a leading cause of pharmacoresistant epilepsy in pediatric populations, although its contribution to epileptogenesis remains incompletely understood. Recent findings indicate that hyperexcitability might stem from peripheral areas that are not dysplastic, rather than from the malformation itself. However, consid-ering the significant variability associated with these malformations, it remains challenging to clarify whether this degree of disorganization contributes to changes in activity. In this study, we used the carmustine-induced animal model to investigate how varying degrees of cortical malformation influence neural dynamics. Local field potentials (LFP) were recorded using a multielectrode array (MEA) during both spontaneous activity and external perturbation. We developed a novel metric to quantify spatial heterogeneity in signal organization and evaluated its association with excitation-inhibition (E/I) balance. Our results reveal that alterations such as the aperiodic exponent value and the sparcity of clustering in signal classification are related to the extent and distribution of cortical abnormalities, underscoring the functional relevance of cytoarchitectural variability. This work advances the understanding of FCD-related network dysfunction and introduces analytical approaches with potential translational value for neuroscience research and pre-surgical evaluation.