Functional and structural network disorganizations in typical epilepsy with centro-temporal spikes and impact on cognitive neurodevelopment
- 1INSERM U1105 Groupe de Recherches sur l'Analyse Multimodale de la Fonction Cérébrale, France
- 2University Hospital Center (CHU) of Amiens, France
Epilepsy with Centrotemporal Spikes (ECTS) is the most common form of self-limited focal epilepsy. The pathophysiological mechanisms by which ECTS induces neuropsychological impairment in 15–30% of affected children remain unclear.
The objective of this study is to review the current state of knowledge concerning the brain structural and functional changes that may be involved in cognitive dysfunctions in ECTS.
Structural brain imaging suggests the presence of subtle neurodevelopmental changes over the epileptogenic zone and over distant regions in ECTS. This structural remodelling likely occurs prior to the diagnosis and evolves over time, especially in patients with cognitive impairment, suggesting that the epileptogenic processes might interfere with the dynamics of the brain development and/or the normal maturation processes.
Functional brain imaging demonstrates profound disorganization accentuated by IES in the epileptogenic zone and in remote networks in ECTS. Over the epileptogenic zone, the literature demonstrates the existence of local synchronization/desynchronization and higher levels of neuronal activity which are effective several hundred milliseconds before the IES. In the same time window, desynchronization and changes in neuronal activity are also observed in bilateral distant networks, notably in the frontal and temporal lobes. This is associated with alteration of global small-world properties towards a more random network. The direction of information flow between the various brain regions demonstrates that, in ECTS, the epileptogenic zone constitutes the key area at the origin of IES propagation towards distant cortical regions, including frontal areas.
Altogether, structural and functional network disorganizations, in terms of: (i) power spectral values, (ii) functional and effective connectivity, are likely to participate in the cognitive impairment commonly reported in children with ECTS. These results suggest a central and causal role of network disorganizations related to IES in the neuropsychological impairment described in ECTS children.
Keywords: Benign Epilepsy with Centro Temporal Spike, Neurocognitive impairment (NCI), interictal epileptic spike, high density EEG, Time frequency analysis, connectivity
Received: 02 Apr 2019;
Accepted: 15 Jul 2019.
Copyright: © 2019 Emilie, Mahmoudzadeh, Adebimpe and Wallois. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Bourel-Ponchel Emilie, INSERM U1105 Groupe de Recherches sur l'Analyse Multimodale de la Fonction Cérébrale, Amiens, Picardy, France, firstname.lastname@example.org