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Cortical local and long-range synchronization interplay in human absence seizure initiation.

Abstract : Brain activity relies on transient, fluctuating interactions between segregated neuronal populations. Synchronization within a single and between distributed neuronal clusters reflects the dynamics of these cooperative patterns. Thus absence epilepsy can be used as a model for integrated, large-scale investigation of the emergence of pathological collective dynamics in the brain. Indeed, spike-wave discharges (SWD) of an absence seizure are thought to reflect abnormal cortical hypersynchronization. In this paper, we address two questions: how and where do SWD arise in the human brain? Therefore, we explored the spatio-temporal dynamics of interactions within and between widely distributed cortical sites using magneto-encephalographic recordings of spontaneous absence seizures. We then extracted, from their time-frequency analysis, local synchronization of cortical sources and long-range synchronization linking distant sites. Our analyses revealed a reproducible sequence of 1) long-range desynchronization, 2) increased local synchronization and 3) increased long-range synchronization. Although both local and long-range synchronization displayed different spatio-temporal profiles, their cortical projection within an initiation time window overlap and reveal a multifocal fronto-central network. These observations contradict the classical view of sudden generalized synchronous activities in absence epilepsy. Furthermore, they suggest that brain states transition may rely on multi-scale processes involving both local and distant interactions.
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Contributor : Olivier Colliot Connect in order to contact the contributor
Submitted on : Wednesday, March 27, 2013 - 7:01:43 PM
Last modification on : Friday, August 5, 2022 - 3:41:14 AM



Frédérique Amor, Sylvain Baillet, Vincent Navarro, Claude Adam, Jacques Martinerie, et al.. Cortical local and long-range synchronization interplay in human absence seizure initiation.. NeuroImage, Elsevier, 2009, 45 (3), pp.950-62. ⟨10.1016/j.neuroimage.2008.12.011⟩. ⟨hal-00805418⟩



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