Epilepsy research
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Microdeletions at 15q11.2, 15q13.3 and 16p13.11 are known genetic risk factors for idiopathic generalized epilepsies and other neurodevelopmental disorders. The full phenotypic range of this microdeletion triad in pediatric epilepsies is unknown. We attempted to describe associated phenotypes in a cohort of pediatric epilepsy patients. ⋯ In contrast to previous reports, these recurrent microdeletions are virtually absent in focal epilepsies, FS, FS+ and GEFS+. Microdeletion carriers have a five-fold risk to present with various degrees of ID compared to patients without these risk factors. This microdeletion triad might help delineate a novel spectrum of epilepsy phenotypes classifiable through clinical, electrographic and genetic data.
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MRI is routinely used in patients undergoing intracerebral electroencephalography (icEEG) in order to precisely locate the position of intracerebral electrodes. In contrast, fMRI has been considered unsafe due to suspected greater risk of radiofrequency-induced (RF) tissue heating at the vicinity of intracerebral electrodes. We determined the possible temperature change at the tip of such electrodes during fMRI sessions in phantom and animals. ⋯ Variation of the temperature depends on the electrode and wire position relative to the transmit body coil and orientation of the constant magnetic field (B0). EPI sequence with intracerebral electrodes appears as safe as standard T1 and T2 sequence for implanted electrodes placed perpendicular to the z-axis of the magnetic bore, using a 1.5T MRI system, with the free-end wires moving posteriorly, in phantom and animals.
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The structural connection patterns of the human brain are the underlying bases for functional connectivity. Although abnormal functional connectivity has been uncovered in childhood absence epilepsy (CAE) in previous electroencephalography and functional magnetic resonance imaging studies, little is known regarding the structural connectivity in CAE. We hypothesized that the structural connectivity would be disrupted in response to the decreased brain function in CAE. ⋯ The present study demonstrated, for the first time, the disrupted topological organization of WM networks in CAE. The decreased connectivity and efficiency in the orbitofrontal and sub-cortical regions may serve as anatomical evidence to support the functional abnormalities related to the epileptic discharges observed in CAE. Moreover, the orbitofrontal sub-network may play a key role in CAE. These findings open up new avenues toward the understanding of absence epilepsy.