EEG-Findings during long-term treatment with everolimus in TSC-associated and therapy-resistant epilepsies in children.

Aim: This prospective observational study evaluated the long-term EEG changes in children treated with everolimus (EVO) for refractory TSC-associated epilepsy. Changes in EEG-abnormalities were related to developmental outcomes.

Methods: Thirteen children treated with EVO were examined for EEG-recorded seizures and interictal epileptic discharges (IED) during a 72-hour-video-EEG-monitoring, which was performed at baseline and repeated at follow-up intervals of at least 9 months.

Neuronal networks underlying ictal and subclinical discharges in childhood absence epilepsy.

Childhood absence epilepsy (CAE), involves 3 Hz generalized spikes and waves discharges (GSWDs) on the electroencephalogram (EEG), associated with ictal discharges (seizures) with clinical symptoms and impairment of consciousness and subclinical discharges without any objective clinical symptoms or impairment of consciousness. This study aims to comparatively characterize neuronal networks underlying absence seizures and subclinical discharges, using source localization and functional connectivity (FC), to better understand the pathophysiological mechanism of these discharges. Routine EEG data from 12 CAE patients, consisting of 45 ictal and 42 subclinical discharges were selected.

Differentiating ictal/subclinical spikes and waves in childhood absence epilepsy by spectral and network analyses: A pilot study.

Objective: Childhood absence epilepsy (CAE) is a disease with distinct seizure semiology and electroencephalographic (EEG) features. Differentiating ictal and subclinical generalized spikes and waves discharges (GSWDs) in the EEG is challenging, since they appear to be identical upon visual inspection. Here, spectral and functional connectivity (FC) analyses were applied to routine EEG data of CAE patients, to differentiate ictal and subclinical GSWDs.

Source imaging of deep-brain activity using the regional spatiotemporal Kalman filter.

Background And Objective: The human brain displays rich and complex patterns of interaction within and among brain networks that involve both cortical and subcortical brain regions. Due to the limited spatial resolution of surface electroencephalography (EEG), EEG source imaging is used to reconstruct brain sources and investigate their spatial and temporal dynamics. The majority of EEG source imaging methods fail to detect activity from subcortical brain structures.

Source reconstruction via the spatiotemporal Kalman filter and LORETA from EEG time series with 32 or fewer electrodes.

The clinical routine of non-invasive electroencephalography (EEG) is usually performed with 8-40 electrodes, especially in long-term monitoring, infants or emergency care. There is a need in clinical and scientific brain imaging to develop inverse solution methods that can reconstruct brain sources from these low-density EEG recordings. In this proof-of-principle paper we investigate the performance of the spatiotemporal Kalman filter (STKF) in EEG source reconstruction with 9-, 19- and 32- electrodes.

Spatial projection as a preprocessing step for EEG source reconstruction using spatiotemporal Kalman filtering.

The reconstruction of brain sources from non-invasive electroencephalography (EEG) or magnetoencephalography (MEG) via source imaging can be distorted by information redundancy in case of high-resolution recordings. Dimensionality reduction approaches such as spatial projection may be used to alleviate this problem. In this proof-of-principle paper we apply spatial projection to solve the problem of information redundancy in case of source reconstruction via spatiotemporal Kalman filtering (STKF), which is based on state-space modeling.

Neuronal networks in epileptic encephalopathies with CSWS.

Objective: The aim of our study was to investigate the neuronal networks underlying background oscillations of epileptic encephalopathy with continuous spikes and waves during slow sleep (CSWS).

Methods: Sleep electroencephalography (EEG) studies before and after the treatment were investigated in 15 patients with CSWS. To investigate functional and effective connectivity within the network generating the delta activity in the background sleep EEG, the methods of dynamic imaging of coherent sources (DICS) and renormalized partial directed coherence (RPDC) were applied.

The choice of the source space and the Laplacian matrix in LORETA and the spatio-temporal Kalman filter EEG inverse methods.

The discretization of the brain and the definition of the Laplacian matrix influence the results of methods based on spatial and spatio-temporal smoothness, since the Laplacian operator is used to define the smoothness based on the neighborhood of each grid point. In this paper, the results of low resolution electromagnetic tomography (LORETA) and the spatiotemporal Kalman filter (STKF) are computed using, first, a greymatter source space with the standard definition of the Laplacian matrix and, second, using a whole-brain source space and a modified definition of the Laplacian matrix. Electroencephalographic (EEG) source imaging results of five inter-ictal spikes from a pre-surgical patient with epilepsy are used to validate the two aforementioned approaches.

The performance of the spatiotemporal Kalman filter and LORETA in seizure onset localization.

The assumption of spatial-smoothness is often used to solve the bioelectric inverse problem during electroencephalographic (EEG) source imaging, e.g., in low resolution electromagnetic tomography (LORETA).

Altered information processing in children with focal epilepsies with and without intellectual disability.

The aim of this exploratory study was to investigate the relationship between focal interictal epileptiform discharges (IEDs), intellectual disability and cortical information processing in children with partial epilepsy. Two groups of patients--Group 1 (n = 9 patients) with focal IEDs and normal IQ and Group 2 (n = 10 patients) with focal IEDs and intellectual disability--were compared with 14 healthy control participants. A computerized choice reaction time task (go/no-go paradigm) was performed and event-related potentials (ERPs) were recorded.

Risk factors of cognitive outcome in patients with atypical benign partial epilepsy/pseudo-Lennox syndrome (ABPE/PLS) and continues spike and wave during sleep (CSWS).

Background: Atypical benign partial epilepsy/pseudo-Lennox syndrome (ABPE/PLS) and continues spike and wave during sleep (CSWS) belong to a spectrum of idiopathic focal epilepsy syndromes ranging from benign Rolandic epilepsy to more severe seizure disorders, which are commonly characterized by the association of various epileptic seizure types, aggravation of spike-wave discharges during slow sleep, and cognitive and/or behavioral disturbances. The Aim of our study was to evaluate the risk factors that influence cognitive outcome in patients with ABPE/PLS and CSWS in a retrospective analysis.

Methods: Thirty patients fulfilled the diagnostic criteria for ABPE/PLS and 12 for CSWS and were chosen for the descriptive analysis.

Neuronal networks in west syndrome as revealed by source analysis and renormalized partial directed coherence.

West syndrome is a severe epileptic encephalopathy of infancy with a poor developmental outcome. This syndrome is associated with the pathognomonic EEG feature of hypsarrhythmia. The aim of the study was to describe neuronal networks underlying hypsarrhythmia using the source analysis method (dynamic imaging of coherent sources or DICS) which represents an inverse solution algorithm in the frequency domain.

Electroencephalographic features in dravet syndrome: five-year follow-up study in 22 patients.

The aim of the study was to evaluate interictal electroencephalogram features in 22 patients with Dravet syndrome from the onset of the disease through the next 5 years. Electroencephalogram was abnormal in 5 patients (22.7%) at onset, and in 17 (77.

Convulsions associated with gastroenteritis in the spectrum of benign focal epilepsies in infancy: 30 cases including four cases with ictal EEG recording.

Benign convulsions associated with gastroenteritis are now recognized as a clinical entity, characterized by an acute cluster of afebrile seizures during an episode of mild diarrhoea with excellent prognosis. We observed 30 children who each experienced at least two seizures associated with mild gastroenteritis. The inclusion criteria were: afebrile seizures during gastroenteritis, dehydration at ≤ 5%, normal neurological findings, normal psychomotor development and no underlying pathology according to laboratory and neuroimaging studies.