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Objective Prenatal exposure to antiepileptic drugs ( AEDs) is associated with an increased risk of cognitive dysfunction at early school age. Our aim was to investigate whether signs of adverse drug effects on brain function could be detected already during the first 2 weeks of life. Methods We studied prospectively 56 full-term newborns with prenatal exposure to AEDs and 67 unexposed newborns for the following characteristics: Background information, AED exposure data, pregnancy outcome, neuropsychological evaluation of the mothers, clinical neurologic status with Hammersmith Neonatal Neurological Examination and early cortical activity using electroencephalography ( EEG). For EEG assessment, we developed and provide automated quantitation algorithms of several earlier described features: oscillatory bouts at theta and alpha frequencies, frequency spectra, interhemispheric synchrony, and interburst intervals ( IBIs). Results The AED-exposed newborns had lower limb and axial tone and were less irritable than the unexposed newborns. EEG assessment disclosed significant differences in alpha bouts, in the frequency spectra, as well as in the spatial distributions of interhemispheric synchrony and IBIs. Significance The results indicate that fetal AED exposure may affect early neonatal neurologic status and several features of early cortical activity. The findings suggest that interference of activity-dependent network development may be a possible mechanism to explain the link from fetal AED exposure to later neurocognitive sequelae. [ABSTRACT FROM AUTHOR]

Purpose: Ictal video-electroencephalography (EEG) is commonly used to establish ictal onset-zone location. Recently software development has enabled systematic studies of ictal magnetoencephalography (MEG). In this article, we evaluate the ability of ictal MEG signals to localize the seizure-onset zone. Methods: Twenty-six patients underwent ictal MEG and epilepsy surgery. Prediction of seizure-onset zone by ictal and interictal MEG was retrospectively compared with ictal-onset area found by intracranial EEG in 12 patients. The specificity and sensitivity of the prediction were calculated at hemisphere-lobe (HL) and at hemisphere-lobe-surface (HLS) levels. Key Findings: The sensitivity of ictal MEG source localization was 0.958 on HL and 0.706 on HLS levels, and its specificity was 0.900 on HL and 0.731 on HLS levels. The interictal MEG dipole cluster, defined as >10 dipoles on one lobar surface, had sensitivity of 0.400 and specificity of 0.769. Ictal MEG was equally sensitive and specific on dorsolateral and nondorsolateral neocortical surfaces up to a depth of 4 cm from the scalp. Significance: Sources of ictal-onset MEG signals and interictal dipole clusters are essentially equally specific in estimation of the ictal-onset zone on lobar surface resolution, but ictal MEG is more sensitive. On the lobe resolution, ictal MEG estimates ictal-onset zone with high sensitivity and specificity. [ABSTRACT FROM AUTHOR]