Cognitive and behavioral outcomes in benign childhood epilepsy with centrotemporal spikes

Pediatric epilepsy syndromes with associated developmental impairment

In 2022, the International League Against Epilepsy revised their classification of epilepsy syndromes for clinicians to better understand the relationships between different epilepsy syndromes, their underlying causes, and their associated developmental and behavioral features. This review highlights portions of the current classification with an emphasis on epilepsy syndromes that readily present with developmental challenges and provides a unique framework, based on electroencephalography, to easily identify and understand these syndromes. Included in this review are a helpful categorization scheme with visual aid, descriptions of updated epilepsy syndromes, figures of relevant identifiers of syndrome and information regarding future directions toward treatment and research. Covered syndromes include developmental and epileptic encephalopathy, Dravet syndrome, Rasmussen syndrome, and infantile epileptic spasm syndrome, among others. WHAT THIS PAPER ADDS: The revised epilepsy syndrome classification by the International League Against Epilepsy aims to improve the outcomes for children with epilepsy. The electroencephalography features of epilepsy syndromes are grouped based on a categorization model. This model allows clinicians to understand overlapping phenotypes and aid with both identification and diagnosis.

Recognition memory deficits detected through eye-tracking in well-controlled children with self-limited epilepsy with centrotemporal spikes

OBJECTIVE

Children with self-limited epilepsy characterized by centrotemporal spikes (SeLECTS) exhibit cognitive deficits in memory during the active phase, but there is currently a lack of studies and techniques to assess their memory development after well-controlled seizures. In this study, we employed eye-tracking techniques to investigate visual memory and its association with clinical factors and global intellectual ability, aiming to identify potential risk factors by examining encoding and recognition processes.

METHODS

A total of 26 recruited patients diagnosed with SeLECTS who had been seizure-free for at least 2 years, along with 24 control subjects, underwent Wechsler cognitive assessment and an eye-movement-based memory task while video-electroencephalographic (EEG) data were recorded. Fixation and pupil data related to eye movements were utilized to detect distinct memory processes and subsequently to compare the cognitive performance of patients exhibiting different regression patterns on EEG.

RESULTS

The findings revealed persistent impairments in visual memory among children with SeLECTS after being well controlled, primarily observed in the recognition stage rather than the encoding phase. Furthermore, the age at onset, frequency of seizures, and interictal epileptiform discharges exhibited significant correlations with eye movement data.

SIGNIFICANCE

Children with SeLECTS exhibit persistent recognition memory impairment after being well controlled for the disease. Controlling the frequency of seizures and reducing prolonged epileptiform activity may improve memory cognitive development. The application of the eye-tracking technique may provide novel insights into exploring memory cognition as well as underlying mechanisms associated with pediatric epilepsy.

Brain structural changes and molecular analyses in children with benign epilepsy with centrotemporal spikes

BACKGROUND

Benign epilepsy with centrotemporal spikes (BECTS) is a common childhood epilepsy syndrome, accompanied by behavioral problems and cognitive impairments. Previous studies of BECTS-related brain structures applied univariate analysis and showed inconsistent results. And neurotransmitter patterns associated with brain structural alterations were still unclear.

METHODS

Structural images of twenty-one drug-naïve children with BECTS and thirty-five healthy controls (HCs) were scanned. Segmented gray matter volume (GMV) images were decomposed into independent components (ICs) using the source-based morphometry method. Then spatial correlation analyses were applied to examine possible relationships between GMV changes and neurotransmitter systems.

RESULTS

Compared with HCs, drug-naïve children with BECTS showed increased volume in one GMV component (IC7), including bilateral precentral gyrus, bilateral supplementary motor area, left superior frontal cortex, bilateral middle/ inferior frontal cortex and bilateral anterior/ middle cingulate cortex. A positive correlation was observed between one GMV component (IC6) and seizure frequency. There were significantly positive correlations between abnormal GMV in IC7 and serotonergic, GABAergic and glutamatergic systems.

CONCLUSION

These findings provided further evidence of changed GMV in drug-naïve children with BECTS related to their behavioral problems and cognitive impairments, and associated neurotransmitters which could help to better understand neurobiological mechanisms and underlying molecular mechanisms of BECTS.

IMPACT

The article provides further evidence of changed gray matter volume in drug-naïve children with BECTS related to their behavioral problems and cognitive impairments as well as associated neurotransmitters. Most literature to date has applied univariate analysis and showed inconsistent results, and neurotransmitter patterns associated with brain structural alterations were still unclear. Therefore, this article uses multivariate method and JuSpace toolbox to fill the gap. Significantly increased gray matter volume was found in drug-naïve children with BECTS compared with healthy controls. Abnormal gray matter volume was significantly correlated with clinical data and specific neurotransmitters.

Cognitive development in children with new-onset Rolandic epilepsy and Rolandic discharges without seizures: Focusing on intelligence, visual perception, working memory and the role of parents' education

PURPOSE

Our aim was to assess intelligence, visual perception and working memory in children with new-onset Rolandic epilepsy (RE) and children with Rolandic discharges without seizures (RD).

METHODS

The participants in the study were 12 children with RE and 26 children with RD aged 4 to 10 years (all without medication and shortly after diagnosis) and 31 healthy controls. Their cognitive performance was assessed using the German versions of the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-III), the Wechsler Intelligence Scale for Children (WISC-IV), the Developmental Test of Visual Perception-2 (DTVP-2), the Developmental Test of Visual Perception-Adolescent and Adult (DTVP-A) (each according to age) and the Word Order, Hand Movements and Spatial Memory subtests of the German version of the Kaufman Assessment Battery for Children (K-ABC).

RESULTS

The comparison of the entire group of children with RE/RD and the control group conducted in the first step of our analysis revealed a weaker performance of the children with RE/RD in all cognitive domains. Significant deficits, however, were found exclusively in the RD group. Compared to the controls, they performed significantly weaker regarding IQ (full scale IQ: p < 0.001; verbal IQ: p < 0.001; performance IQ: p = 0.002; processing speed: p = 0.005), visual perception (general visual perception: p = 0.005; visual-motor integration: p = 0.002) and working memory (WISC working memory: p = 0.002 and K-ABC Word Order (p = 0.010) and Hand Movements (p = 0.001) subtests. Also, the children without seizures scored significantly lower than those with seizures on the WISC Working Memory Index (p = 0.010) and on the K-ABC Word Order (p = 0.021) and Hand Movements (p = 0.027) subtests. Further analysis of our data demonstrated the particular importance of the family context for child development. Significant cognitive deficits were found only in children with RD from parents with lower educational levels. This group consistently scored lower compared to the control group regarding IQ (full scale IQ: p < 0.001; verbal IQ: p < 0.001; performance IQ: p = 0.012; processing speed: p = 0.034), visual perception (general visual perception: p = 0.018; visual-motor integration: p = 0.010) and auditory working memory (WISC working memory: p = 0.014). Furthermore, compared to the children with RE, they performed significantly weaker on verbal IQ (p = 0.020), auditory working memory consistently (WISC working memory: p = 0.027; K-ABC: Word Order: p = 0.046) as well as in one of the K-ABC spatial working memory subtests (Hand Movements: p = 0.029). Although we did not find significant deficits in children with new-onset RE compared to healthy controls, the performance of this group tended to be weaker more often. No statistically significant associations were observed between selected clinical markers (focus types: centrotemporal/other foci/laterality of foci and spread of Rolandic discharges) and cognitive test results. Except for spatial working memory, we also found no evidence that the age of our patients at the time of study participation was of significant importance to their cognitive performance.

CONCLUSIONS

Our study provides some evidence that children with Rolandic discharges, with and without seizures, may be at higher risk of cognitive impairment. In addition to medical care, we emphasise early differentiated psychosocial diagnostics to provide these children and their families with targeted support if developmental problems are present.

High-Density (HD) Scalp EEG Findings in "Benign" Childhood Epilepsy with Centrotemporal Spikes (BCECTS)

Despite characteristic clinical and scalp EEG findings, BCECTS pathophysiology is unclear regarding involvement of large-scale neuronal networks. Higher number of scalp electrodes with HD-EEG may promote accurate localization of the cortical generators in BCECTS providing additional insight in those with neurocognitive problems. We aimed to determine the value of visual interpretation of topographical maps using 256 channels (when compared to standard 21 channel array) HD-EEG in BCECTS and attempted to source localize interictal discharges (IEDs) using Geosource 2 software. Patient records were reviewed for demographic, seizure, brain magnetic resonance imaging (MRI) details; scalp and HD-EEG findings. HD-EEG software was used to review raw EEG data (21 scalp EEG electrodes were compared to 256 HD-EEG electrodes); select, average, and source localize IEDs.Five BCECTS patients with HD-EEG were identified. Seizure onset age ranged from 5-11 years with 1-18 lifetime seizures; both focal (n = 3) and focal to bilateral tonic-clonic (n = 2). Neurocognitive co-morbidities noted in our cohort included attention deficit hyperactivity disorder, speech/developmental delay and a specific learning disorder. Scalp EEG showed typical findings with IEDs over the centrotemporal regions (bilateral n = 3; unilateral n = 2). Visualization and inspection of expanded coverage topographic maps with HD-EEG showed well-defined islands of maximum negativity and positivity of a dipole compared to conventional channels where boundary delineation was obscured. Further, HD-EEG localized IEDs/"spike-generator" to areas such as the pre-and post-central, middle-frontal and temporal gyrus, and the inferior parietal lobule. In BCECTS, HD-EEG may show affection for a broader neural network and may provide a better insight into the associated neurocognitive morbidities.

Interictal magnetic signals in new-onset Rolandic epilepsy may help with timing of treatment selection

OBJECTIVE

With research progress on Rolandic epilepsy (RE), its "benign" nature has been phased out. Clinicians are exhibiting an increasing tendency toward a more assertive treatment approach for RE. Nonetheless, in clinical practice, delayed treatment remains common because of the "self-limiting" nature of RE. Therefore, this study aimed to identify an imaging marker to aid treatment decisions and select a more appropriate time for initiating therapy for RE.

METHODS

We followed up with children newly diagnosed with RE, classified them into medicated and non-medicated groups according to the follow-up results, and compared them with matched healthy controls. Before beginning follow-up visits, interictal magnetic data were collected using magnetoencephalography in treatment-naïve recently diagnosed patients. The spectral power of the whole brain during initial diagnosis was determined using minimum normative estimation combined with the Welch technique.

RESULTS

A difference was observed in the magnetic source intensity within the left caudal anterior cingulate and precentral and postcentral gyri in the delta band between the medicated and non-medicated groups. The results revealed good discriminatory ability within the receiver operator characteristic curve. In the medicated group, there was a specific change in the frontotemporal magnetic source intensity, which shifted from high to low frequencies, compared with the healthy control group.

SIGNIFICANCE

The intensity of the precentral gyrus magnetic source within the delta band showed good specificity. Considering the rigor of initial treatment, the intensity of the precentral gyrus magnetic source can provide some help as an imaging marker for initial RE treatment, particularly for the timing of treatment initiation.

How the Spreading and Intensity of Interictal Epileptic Activity Are Associated with Visuo-Spatial Skills in Children with Self-Limited Focal Epilepsy with Centro-Temporal Spikes

This paper investigates brain-behaviour associations between interictal epileptic discharges and cognitive performance in a population of children with self-limited focal epilepsy with centro-temporal spikes (SeLECTS). Sixteen patients with SeLECTS underwent an extensive neuropsychological assessment, including verbal short-term and episodic memory, non-verbal short-term memory, attentional abilities and executive function. Two quantitative EEG indices were analysed, i.e., the Spike Wave Index (SWI) and the Spike Wave Frequency (SWF), and one qualitative EEG index, i.e., the EEG score, was used to evaluate the spreading of focal SW to other parts of the brain. We investigated associations between EEG indices and neuropsychological performance with non-parametric Spearman correlation analyses, including correction for multiple comparisons. The results showed a significant negative correlation between (i) the awake EEG score and the Block Tapping Test, a visuo-spatial short-term memory task, and (ii) the sleep SWI and the Tower of London, a visuo-spatial planning task (pcorr < 0.05). These findings suggest that, in addition to the usual quantitative EEG indices, the EEG analysis should include the qualitative EEG score evaluating the spreading of focal SW to other parts of the brain and that neuropsychological assessment should include visuo-spatial skills.

Care and three-year outcomes of children with Benign Epilepsy with Centro-Temporal Spikes in England

PURPOSE

Benign Epilepsy with Centro-Temporal Spikes (BECTS) is a pediatric epilepsy with typically good seizure control. Although BECTS may increase patients' risk of developing neurological comorbidities, their clinical care and short-term outcomes are poorly quantified.

METHODS

We retrospectively assessed adherence to National Institute for Health and Care Excellence (NICE) guidelines relating to specialist referral, electroencephalogram (EEG) conduct and annual review in the care of patients with BECTS, and measured their seizure, neurodevelopmental and learning outcomes at three years post-diagnosis.

RESULTS

Across ten centers in England, we identified 124 patients (74 male) diagnosed with BECTS between 2015 and 2017. Patients had a mean age at diagnosis of 8.0 (95% CI = 7.6-8.4) years. 24/95 (25%) patients were seen by a specialist within two weeks of presentation; 59/100 (59%) received an EEG within two weeks of request; and 59/114 (52%) were reviewed annually. At three years post-diagnosis, 32/114 (28%) experienced ongoing seizures; 26/114 (23%) had reported poor school progress; 15/114 (13%) were diagnosed with a neurodevelopmental disorder (six autism spectrum disorder, six attention-deficit/hyperactivity disorder); and 10/114 (8.8%) were diagnosed with a learning difficulty (three processing deficit, three dyslexia). Center-level random effects models estimated neurodevelopmental diagnoses in 9% (95% CI: 2-16%) of patients and learning difficulty diagnoses in 7% (95% CI: 2-12%).

CONCLUSIONS

In this multicenter work, we found variable adherence to NICE guidelines in the care of patients with BECTS and identified a notable level of neurological comorbidity. Patients with BECTS may benefit from enhanced cognitive and behavioral assessment and monitoring.

Connectivity increases during spikes and spike-free periods in self-limited epilepsy with centrotemporal spikes

OBJECTIVE

To understand the impact of interictal spikes on brain connectivity in patients with Self-Limited Epilepsy with Centrotemporal Spikes (SeLECTS).

METHODS

Electroencephalograms from 56 consecutive SeLECTS patients were segmented into periods with and without spikes. Connectivity between electrodes was calculated using the weighted phase lag index. To determine if there are chronic alterations in connectivity in SeLECTS, we compared spike-free connectivity to connectivity in 65 matched controls. To understand the acute impact of spikes, we compared connectivity immediately before, during, and after spikes versus baseline, spike-free connectivity. We explored whether behavioral state, spike laterality, or antiseizure medications affected connectivity.

RESULTS

Children with SeLECTS had markedly higher connectivity than controls during sleep but not wakefulness, with greatest difference in the right hemisphere. During spikes, connectivity increased globally; before and after spikes, left frontal and bicentral connectivity increased. Right hemisphere connectivity increased more during right-sided than left-sided spikes; left hemisphere connectivity was equally affected by right and left spikes.

CONCLUSIONS

SeLECTS patient have persistent increased connectivity during sleep; connectivity is further elevated during the spike and perispike periods.

SIGNIFICANCE

Testing whether increased connectivity impacts cognition or seizure susceptibility in SeLECTS and more severe epilepsies could help determine if spikes should be treated.

Relationship between brain activity, cognitive function, and sleep spiking activation in new-onset self-limited epilepsy with centrotemporal spikes

Objective

This study aimed to investigate the relationship between cognitive function sleep spiking activation and brain activity in self-limited epilepsy with centrotemporal spikes (SeLECTS).

Methods

We used spike-wave index (SWI), which means the percentage of the spike and slow wave duration to the total non-REM (NREM) sleep time, as the grouping standard. A total of 14 children with SeLECTS (SWI ≥ 50%), 21 children with SeLECTS (SWI &lt; 50%), and 20 healthy control children were recruited for this study. Cognitive function was evaluated using the Wechsler Intelligence Scale for Children, Fourth Edition (Chinese version) (WISC-IV). Magnetic source activity was assessed using magnetoencephalography calculated for each frequency band using the accumulated source imaging (ASI) technique.

Results

Children with SeLECTS (SWI ≥ 50%) had the lowest cognitive function scores, followed by those with SeLECTS (SWI &lt; 50%) and then healthy controls. There were significant differences in the localization of magnetic source activity between the three groups: in the alpha (8–12 Hz) frequency band, children with SeLECTS (SWI ≥ 50%) showed deactivation of the medial frontal cortex (MFC) region; in the beta (12–30 Hz) frequency band, children with SeLECTS (SWI ≥ 50%) showed deactivation of the posterior cingulate cortex (PCC) segment; and in the gamma (30–80 Hz) frequency band, children in the healthy group showed activation of the PCC region.

Conclusion

This study revealed significant decreases in cognitive function in children with SeLECTS (SWI ≥ 50%) compared to children with SeLECTS (SWI &lt; 50%) and healthy children, as well as significant differences in magnetic source activity between the three groups. The findings suggest that deactivation of magnetic source activity in the PCC and MFC regions is the main cause of cognitive function decline in SeLECTS patients with some frequency dependence.

Alterations in the default mode network in rolandic epilepsy with mild spike-wave index in non-rapid eye movement sleep

Purpose

Rolandic epilepsy (RE) is one of the most common epilepsy syndromes during childhood. The aim of this study was to investigate the alterations in the default mode network (DMN) of RE patients whose spike-wave index (SWI) was within the 50–85% range during non-rapid eye movement (NREM) during sleep, as well as to detect early neuroimaging markers.

Methods

Resting-state data was recorded for each subject using magnetoencephalography (MEG). DMN-related brain regions were chosen as regions of interest. The spectral power and functional connectivity (FC) of the DMN were estimated through the use of minimum norm estimation (MNE) combined with Welch technique and corrected amplitude envelope correlation (AEC-c).

Results

The patient group included 20 patients with NREM phase 50% ≤ SWI < 85% (mild SWI group), and 18 typical RE patients (SWI < 50% group). At the regional level, the mild SWI group exhibited enhanced spectral power in the delta band of the bilateral posterial cingulate cortex and attenuated the spectral power in the alpha band of the bilateral posterial cingulate cortex. Enhanced spectral power in the bilateral precuneus (PCu) in the delta band and attenuated spectral power in the right lateral temporal cortex (LTC) in the alpha band were common across all RE patients. At the FC level, patients in the mild SWI group indicated increased AEC-c values between the bilateral posterial cingulate cortex in the delta band and between the left medial frontal cortex (MFC) and bilateral posterial cingulate cortex in the alpha band. Increased AEC-c values between the right PCu and left MFC in the delta band, and between the left PCu and right MFC in the theta band, were common across all RE patients. Moreover, the spectral power in the bilateral posterial cingulate cortex in the alpha band and the AEC-c value between the bilateral posterial cingulate cortex in the delta band demonstrated good discrimination ability.

Conclusion

The spectral power of the bilateral posterior cingulate cortex (PCC) in the alpha band and the AEC-c value between the bilateral PCC in the delta band may be promising indicators of early differentiation between mild SWI and typical RE.

High-Frequency Oscillations and Epileptogenic Network

Epilepsy is a network disease caused by aberrant neocortical large-scale connectivity spanning regions on the scale of several centimeters. High-frequency oscillations, characterized by the 80-600 Hz signals in electroencephalography, have been proven to be a promising biomarker of epilepsy that can be used in assessing the severity and susceptibility of epilepsy as well as the location of the epileptogenic zone. However, the presence of a high-frequency oscillation network remains a topic of debate as high-frequency oscillations have been previously thought to be incapable of propagation, and the relationship between high-frequency oscillations and the epileptogenic network has rarely been discussed. Some recent studies reported that high-frequency oscillations may behave like networks that are closely relevant to the epileptogenic network. Pathological highfrequency oscillations are network-driven phenomena and elucidate epileptogenic network development; high-frequency oscillations show different characteristics coincident with the epileptogenic network dynamics, and cross-frequency coupling between high-frequency oscillations and other signals may mediate the generation and propagation of abnormal discharges across the network.

Whole-Brain Dynamic Resting-State Functional Network Analysis in Benign Epilepsy with Centrotemporal Spikes

Benign epilepsy with centrotemporal spikes (BECTS), the most common type of epilepsy among children, is considered a network disorder. Both fMRI and EEG source imaging (ESI) studies have indicated that BECTS is associated with static resting-state functional network (SFN) alterations (e.g., decreased global efficiency) in source space. However, we find that the abovementioned alterations are not significant when the SFN calculations are performed in the scalp space using only clinical routine low-density (e.g., 19 channels) EEG recordings (shown in our results). In the context of EEG microstates, it is clear that networks in the scalp space with resting-state EEG recordings dynamically reconfigure in a well-organized way based on different functional states. We are therefore inspired to propose a whole-brain dynamic resting-state functional network (DFN) computation method based on resting-state low-density EEG recordings with four classical microstates in scalp space. Notably, on the one hand, this approach is suitable for clinical conditions, and, on the other hand, the dynamic alternations calculated with a DFN may promote our understanding of how the networks change in BECTS. We analysed the changes in a DFN in six frequency bands (, low, high, and) in patients with BECTS compared to those for healthy controls. Superior to traditional SFNs, the proposed DFN can reveal significant differences between individuals with BECTS and healthy controls (e.g., lower global efficiency), thus matching traditional fMRI and ESI methods in the source space. Our method directly performs DFN computations from low-density EEG recordings and avoids complex ESI computations, making it promising for clinical applications, especially in the outpatient diagnosis stage.

Source EEG reveals that Rolandic epilepsy is a regional epileptic encephalopathy

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Children with RE have fewer spindles but they have typical time–frequency features.

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Spindle deficits extend to multiple cortical regions in Rolandic epilepsy.

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Cognitive deficits are predicted by spindle rate in Rolandic epilepsy.

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Regional spindle rate predicts motor deficits better than Rolandic spindle deficit.

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Spindle features in RE identify a regional thalamocortical epileptic encephalopathy.

Rolandic epilepsy is the most common form of epileptic encephalopathy, characterized by sleep-potentiated inferior Rolandic epileptiform spikes, seizures, and cognitive deficits in school-age children that spontaneously resolve by adolescence. We recently identified a paucity of sleep spindles, physiological thalamocortical rhythms associated with sleep-dependent learning, in the Rolandic cortex during the active phase of this disease. Because spindles are generated in the thalamus and amplified through regional thalamocortical circuits, we hypothesized that: 1) deficits in spindle rate would involve but extend beyond the inferior Rolandic cortex in active epilepsy and 2) regional spindle deficits would better predict cognitive function than inferior Rolandic spindle deficits alone. To test these hypotheses, we obtained high-resolution MRI, high-density EEG recordings, and focused neuropsychological assessments in children with Rolandic epilepsy during active (n = 8, age 9–14.7 years, 3F) and resolved (seizure free for > 1 year, n = 10, age 10.3–16.7 years, 1F) stages of disease and age-matched controls (n = 8, age 8.9–14.5 years, 5F). Using a validated spindle detector applied to estimates of electrical source activity in 31 cortical regions, including the inferior Rolandic cortex, during stages 2 and 3 of non-rapid eye movement sleep, we compared spindle rates in each cortical region across groups. Among detected spindles, we compared spindle features (power, duration, coherence, bilateral synchrony) between groups. We then used regression models to examine the relationship between spindle rate and cognitive function (fine motor dexterity, phonological processing, attention, and intelligence, and a global measure of all functions). We found that spindle rate was reduced in the inferior Rolandic cortices in active but not resolved disease (active P = 0.007; resolved P = 0.2) compared to controls. Spindles in this region were less synchronous between hemispheres in the active group (P = 0.005; resolved P = 0.1) compared to controls; but there were no differences in spindle power, duration, or coherence between groups. Compared to controls, spindle rate in the active group was also reduced in the prefrontal, insular, superior temporal, and posterior parietal regions (i.e., “regional spindle rate”, P < 0.039 for all). Independent of group, regional spindle rate positively correlated with fine motor dexterity (P < 1e-3), attention (P = 0.02), intelligence (P = 0.04), and global cognitive performance (P < 1e-4). Compared to the inferior Rolandic spindle rate alone, models including regional spindle rate trended to improve prediction of global cognitive performance (P = 0.052), and markedly improved prediction of fine motor dexterity (P = 0.006). These results identify a spindle disruption in Rolandic epilepsy that extends beyond the epileptic cortex and a potential mechanistic explanation for the broad cognitive deficits that can be observed in this epileptic encephalopathy.

Neuropsychological and behavioral profiles of self-limited epileptic syndromes of childhood: a cross-syndrome comparison

Childhood epilepsy with centro-temporal spikes (CECTS), Childhood absence epilepsy (CAE) and Panayiotopoulos syndrome (PS) are some of the most common pediatric epileptic syndromes. Despite the relatively benign (self-limited) course of epilepsy, current evidence suggests that these conditions are associated with an increased risk of neuropsychological and behavioral comorbidities. This study provides a cross-epileptic syndromes' comparison reporting on the cognitive and behavioral profile of a cohort of 32 children with CECTS (n = 14), CAE (n = 10) and PS (n = 8), aged 6 to 15 years old. Frequent, although often subclinical cognitive difficulties involving attention, executive functions and academic abilities were found in children with CECTS and CAE, and to a lesser extent in PS. Internalizing symptoms (particularly anxiety) were more common in the PS group compared to CECTS and CAE based on parental reports. Correlational analysis revealed a significant correlation between phonemic fluency and seizure-free interval at the time of evaluation, suggesting a beneficial effect of epilepsy remission on this executive function measure in all the three groups. These results add to existing literature providing further detail on neuropsychological and behavioral peculiarities of children with CECTS, CAE, and PS. Moreover, the need for neuropsychological assessment as part of the standard childhood epilepsy evaluation is stressed. The results are discussed in the context of the current literature, highlighting areas of consensus and controversies related to the clinical management of these epileptic syndromes as well as directions for future research.

EMD-WOG-2DCNN based EEG signal processing for Rolandic seizure classification

Objective Approximately 65 million people have epilepsy around the world. Recognition of epilepsy types is the basis to determine the treatment method and predict the prognosis in epilepsy patients. Childhood benign epilepsy with centrotemporal spikes (BECTS) or benign Rolandic epilepsy is the most common focal epilepsy in children, accounting for 15-20% of childhood epilepsies. These EEG patterns of individuals usually predict good treatment responses and prognosis. Until now, the interpretation of EEG still depends entirely on experienced neurologists, which may be a lengthy and tedious task. Method In this article, we proposed a novel machine learning model that efficiently distinguished Rolandic seizures from normal EEG signals. The proposed machine learning model processes the identification procedure in the following order (1) creating preliminary EEG features using signal empirical mode decomposition, (2) applying weighted overlook graph (WOG) to represent the decomposed EMD of IMF, and (3) classifying the results through a two Dimensional Convolutional Neural Network (2DCNN). The performance of our classification model is compared with other representative machine learning models. Results The model offered in this article gains an accuracy performance exceeding 97.6% in the Rolandic dataset, which is higher than other classification models. The effect of the model on the Bonn public dataset is also comparable to existing methods and even performs better in some subsets. Conclusion The purpose of this study is to introduce the most common childhood benign epilepsy type and propose a model that meets the real clinical needs to distinguish this Rolandic EEG pattern from normal signals accurately. Significance Future research will optimize the model to categorize other types of epilepsies beyond BECTS and finally implement them in the hospital system.

Involvement of brain structures in childhood epilepsy with centrotemporal spikes

BACKGROUND

We aimed to investigate electroencephalography (EEG)-functional magnetic resonance imaging (fMRI) findings to elucidate the interictal epileptiform discharge (IED)-related functional alterations in deep brain structures and the neocortex in childhood epilepsy with centrotemporal spikes (CECTS).

METHODS

Ten children with CECTS (median age 8.2 years), referred to our hospital within a year of onset, were eligible for inclusion. They underwent EEG-fMRI recording during sleep. Llongitudinal evaluations, including medical examinations, intelligence tests, and questionnaires about developmental disabilities, were performed. The initial evaluation was performed at the same time as the EEG-fMRI, and the second evaluation was performed over 2 years after the initial evaluation.

RESULTS

Three children were unable to maintain sleep during the EEG-fMRI recording, and the remaining seven children were eligible for further assessment. All patients showed unilateral-dominant centrotemporal spikes during scans. One patient had only positive hemodynamic responses, while the others had both positive and negative hemodynamic responses. All patients showed IED-related hemodynamic responses in the bilateral neocortex. For deep brain structures, IED-related hemodynamic responses were observed in the cingulate gyrus (n = 4), basal ganglia (n = 3), thalamus (n = 2), and default mode network (n = 1). Seizure frequencies at the second evaluation were infrequent or absent, and the longitudinal results of intelligence tests and questionnaires were within normal ranges.

CONCLUSIONS

We demonstrated that IEDs affect broad brain areas, including deep brain structures such as the cingulate gyrus, basal ganglia, and thalamus. Deep brain structures may play an important role in the pathophysiology of CECTS.

Epilepsy Syndromes: Current Classifications and Future Directions

This review describes the clinical presentations and treatment options for commonly recognized epilepsy syndromes in the pediatric age group, based on the 2017 International League Against Epilepsy classification. Structural epilepsies that are amenable to surgical intervention are discussed. Lastly, emerging technologies are reviewed that are expanding our knowledge of underlying epilepsy pathologies and will guide future syndromic classification systems including genetic testing and tissue repositories.

Interictal epileptiform discharges changed epilepsy-related brain network architecture in BECTS

To investigate directed information flow of epileptiform activity in benign epilepsy with centrotemporal spikes (BECTS) during ictal epileptiform discharges (IEDs) and non-IEDs periods. In this multi-center study, a total of 188 subjects, including 50 BECTS and 138 normal children's controls (NCs) from three different centers (Center 1: females/males, 38/55; mean age, 9.33 ± 2.6 years; Center 2: females/males,7/10; mean age, 8.59 ± 2.32 years; Center 3: females/males, 14/14; mean age, 13 ± 3.42 years) were recruited. The BECTS were classified into IEDs (females/males, 12/15; mean age, 8.15 ± 1.68 years) and non-IEDs (females/males, 10/13; mean age, 9.09 ± 1.98 years) subgroups depending on presence of central-temporal spikes from an EEG-fMRI examination. Three new methods, structural equation parametric modeling, dynamic causal modeling and granger causality density (GCD) were used to determine optimal network architectures for BECTS. Three multicentric NCs determined a reliable and consistent network architecture by structural equation parametric modeling method. Further analyses were used for IEDs and non-IEDs to determine the brain network architecture by structural equation parametric modeling, dynamic causal modeling and GCD, respectively. The brain network architecture of IEDs substate, non-IEDs substate and NCs are different. IEDs promoted the driving effect of the Rolandic areas with more output information flows, and increased the targeted effect of the top of pre-/post-central gyrus with more input information flows. The information flow arises from the Rolandic areas, and subsequently propagates to the top of pre-/post-central gyrus and thalamus. From non-IEDs status to IEDs status, the thalamus load may play an important role in the modulation and regulation of epileptiform activity. These findings shed new light on pathophysiological mechanism of directed localization of epileptiform activity in BECTS.

Systematic review of executive functions in children with self-limited epilepsy with centrotemporal spikes

Self-limited Epilepsy with Centrotemporal Spikes (ECTS) is a self-limiting childhood epilepsy with an overall good prognosis. The neurocognitive profile of ECTS shows various degrees of neuropsychological impairment, with speech impairment and executive dysfunction being the most prominent. This review aimed to clarify the executive function (EF) profile of children with ECTS and the clinical variables' impact on these abilities. We conducted a systematic review of the relevant literature for articles published up to January 2021. Demographic and clinical characteristics were abstracted from the original records. EF tasks used in the studies were classified according to Diamond's model, which identified four components: working memory, inhibitory control, cognitive flexibility, and higher order EFs. Twenty-three studies were included. Among the included records, 14 studies examined working memory, 15 inhibitory control, 15 flexibility, 4 higher order EFs, and 2 general EFs. Results confirmed the presence of a specific impairment in two abilities: inhibitory control and cognitive flexibility. This review confirms the need to assess each EF both in verbal and visual-spatial tasks. The early detection of children with ECTS at risk of developing neuropsychological impairment could activate interventions and prevent worse school achievement, social functioning, and a poor quality of life. Systematic review registration: PROSPERO: CRD42021245959.

Altered functional connectivity in newly diagnosed benign epilepsy with unilateral or bilateral centrotemporal spikes: A multi-frequency MEG study

OBJECTIVE

Rolandic epilepsy (RE) is one of the most common forms of epilepsy syndromes in children. The condition is usually accompanied with either unilateral or bilateral centrotemporal epileptic discharge. Despite the term "benign", many studies have reported that children with benign epilepsy with centrotemporal spikes (BECTS) display a range of pervasive cognitive difficulties. In addition, existing research suggests that unilateral and bilateral centrotemporal spikes may affect cognition through different mechanisms. Consequently, the present study aimed to investigate cognitive impairment and the resting-state network topology of children with benign epilepsy with unilateral centrotemporal spikes (U-BECTS) and with bilateral centrotemporal spikes (B-BECTS).

METHODS

This study recruited 14 children with U-BECTS and 14 with B-BECTS. Thereafter, cognition was assessed in 28 children with BECTS and 14 healthy controls, using the fourth edition of the Wechsler Intelligence Scale (WISC-IV). Additionally, the functional network of the brain was constructed through magnetoencephalography (MEG) to record the resting-state brain magnetic signals of the brain and by computing virtual sensor waveforms at the source level. Moreover, graph theory (GT) analysis was used to assess the properties of the brain network.

RESULTS

Children in the B-BECTS group had an earlier onset of epilepsy compared to those in the U-BECTS category. In addition, both the B-BECTS and U-BECTS groups had lower Full Scale Intelligence Quotient (FSIQ), Verbal Comprehension Index (VCI), and Working Memory Index (WMI) scores, compared to the healthy controls although only children in the B-BECTS category had lower Perceptual Reasoning Index (PRI) scores. The results also showed that both BECTS groups had increased frontal cortex connectivity in specific frequency bands. Notably, children with B-BECTS showed a more disorderly and randomized network in the 1-4-Hz and 80-250-Hz frequency bands. Moreover, GT analysis showed that children with B-BECTS had lower clustering coefficient and characteristic path length in the 80-250-Hz frequency bands and higher connection strength in the 4-8-Hz frequency bands. On the other hand, the U-BECTS group had a higher clustering coefficient in the 8-12-Hz frequency bands, compared to the healthy controls. Correlation analysis revealed that there were negative correlations between network parameters, clinical characteristics, and neuropsychological data in the U-BECTS category.

CONCLUSION

The findings revealed that children with BECTS display a diffuse early cognitive deficit. In addition, resting-state suboptimal network topology may be the mechanism of cognitive impairment in children with BECTS. The study also showed that and children with B-BECTS may be at a higher risk of cognitive impairment.

Longitudinal impact of cannabidiol on EEG measures in subjects with treatment-resistant epilepsy

OBJECTIVE

To assess the longitudinal impact of highly purified cannabidiol (CBD) on the electroencephalogram (EEG) of children and adults.

METHODS

Participants received an EEG prior to starting CBD, after approximately 12 weeks of CBD (FU1) and after approximately one year of CBD therapy (FU2). Longitudinal changes in five EEG measures (background frequency, focal slowing, reactivity, frequency of interictal, and ictal discharges) were examined following CBD exposure. Data were compared between pediatric and adult groups at two follow-up time points and within groups over time. Population-averaged models with generalized estimation equations or linear mixed effects models were used to analyze data where appropriate. Correlation analysis was used to assess any association between changes in seizure frequency and changes in EEG interictal discharge (IED) frequency. An alpha level of 5% was used to assess statistical significance.

RESULTS

At FU1, the adult group showed significant decrease in IED/minute (IDR 0.07, 95% CI [0.04, 0.14], P < 0.001); a nonsignificant decrease was observed among children (IDR 0.87, 95% CI [0.47, 0.64], P = 0.67). The difference in changes over time between participant groups was significant after adjusting for last CBD dose (IDR 11.8, 95% CI [4.86, 28.65], P < 0.0001). At FU2 both groups showed significant reduction from baseline after controlling for last CBD dose. This decrease was more pronounced in children (IDR 15.38, 95% CI [4.93, 47.99], P < 0.001). There was no significant correlation between changes in seizure frequency and EEG IED frequency at each timepoint (P = 0.542, 0.917 and 0.989 from baseline to FU1, FU1 to FU2 and baseline to FU2, respectively).

SIGNIFICANCE

This longitudinal EEG study shows that highly-purified plant-derived CBD has positive effects on interictal epileptiform discharge frequency but no effects on other EEG measures. The effect of CBD does not appear to be dose or treatment-duration dependent.

Reliability and availability of granger causality density in localization of Rolandic focus in BECTS

A new method, called granger causality density (GCD), could reflect the directed information flow of the epileptiform activity, which is much closely match with excitatory and inhibitory imbalance theory of epilepsy. Here, we investigated if GCD could effectively localize the Rolandic focus in 50 patients with benign childhood epilepsy with central-temporal spikes (BECTS) from 27 normal children. The BECTS were classified into ictal epileptiform discharges (IEDs; 12 females, 15 males;age, 8.15 ± 1.68 years) and non-IEDs (10 females, 13 males; age, 9.09 ± 1.98 years) subgroups depending on the presence of central-temporal spikes. Multiple correlation-modality analyses (Pearson, across-voxel and across-subject correlations) were used to calculate the couplings between the GCD maps and IEDs-related brain activation map. The individual lateralization coefficient of localize IEDs and multiple regression analysis were used to identify the reliability of the GCD method in localizing the Rolandic focus. In this study, multiple correlation-modality analyses showed that the IEDs-related brain activation map and the GCD maps had highly temporal (coefficient ׀r\= 0.56 ~ 0.65) and spatial (\r\=0.53~0.91) (r\=~ couplings. The proposed GCD method and multiple regression analyses showed consistent findings with the clinical EEG recordings in lateralization of Rolandic focus. Furthermore, the GCD method could reflect the epilepsy-related brain activity during non-IEDs substate. Therefore, the proposed GCD method has the potential to be served as an effective and reliable neuroimaging biomarker to localize the Rolandic focus of BECTS. These findings are critical for clinical early diagnosis, and may promote the progression of treatment and management of pediatric epilepsy.

Reviewing Evidence for the Relationship of EEG Abnormalities and RTT Phenotype Paralleled by Insights from Animal Studies

Rett syndrome (RTT) is a rare neurodevelopmental disorder that is usually caused by mutations of the MECP2 gene. Patients with RTT suffer from severe deficits in motor, perceptual and cognitive domains. Electroencephalogram (EEG) has provided useful information to clinicians and scientists, from the very first descriptions of RTT, and yet no reliable neurophysiological biomarkers related to the pathophysiology of the disorder or symptom severity have been identified to date. To identify consistently observed and potentially informative EEG characteristics of RTT pathophysiology, and ascertain areas most worthy of further systematic investigation, here we review the literature for EEG abnormalities reported in patients with RTT and in its disease models. While pointing to some promising potential EEG biomarkers of RTT, our review identify areas of need to realize the potential of EEG including (1) quantitative investigation of promising clinical-EEG observations in RTT, e.g., shift of mu rhythm frequency and EEG during sleep; (2) closer alignment of approaches between patients with RTT and its animal models to strengthen the translational significance of the work (e.g., EEG measurements and behavioral states); (3) establishment of large-scale consortium research, to provide adequate Ns to investigate age and genotype effects.

Neurocognitive Effects of Antiseizure Medications in Children and Adolescents with Epilepsy

Impairments in cognition are common in epilepsy and may be caused or exacerbated by antiseizure medications (ASMs). Positive effects on cognition may also be seen with some ASMs. Cognitive outcomes are of particular concern in children who may be at an increased risk of cognitive adverse effects of treatment. A comprehensive literature search was conducted in PubMed in order to evaluate the evidence for cognitive changes associated with treatment with ASMs in paediatric epilepsy patients. The ASMs considered were those in the current edition of the British National Formulary (BNF). For most ASMs, remarkably few studies providing robust data on cognitive effects in paediatric patients were identified. The available evidence suggests cognitive impairments may be associated with treatment with phenobarbital. Topiramate and phenytoin are also associated with negative effects on cognition, in particular word-finding difficulties and other language deficits with topiramate, but there are few data available specifically on children. Lamotrigine, levetiracetam and fenfluramine are associated with improvements in some cognitive domains, although it is unclear whether these effects are directly attributable to the medications or are a result of improvements in seizures. Neutral effects on cognition (no substantial evidence of worsening) were suggested for carbamazepine, everolimus, lacosamide, oxcarbazepine, perampanel and valproate. There is limited data for cannabidiol, clobazam, eslicarbazepine acetate, ethosuximide, rufinamide, vigabatrin and zonisamide, although the available evidence suggests these drugs are not associated with severe cognitive impairment. There was too little information to reach conclusions about the effects of brivaracetam, felbamate, gabapentin, pregabalin, retigabine, stiripentol or tiagabine.

Implicit cognitive flexibility in self-limited focal epilepsy of childhood: An HD-EEG study

Self-limited focal epilepsy of childhood (SFEC) is often related to mild impairments in several neuropsychological domains, including cognitive flexibility, which is generally considered a process requiring volition and attention. However, recent evidence showed that it can be implicitly adjusted exploiting simple 'stimulus-response' associations as for example, the probability of the stimulus occurrence. Here, we evaluated the capability to implicitly extract environmental patterns of regularities and use them to flexibly adjust proactive control motor control. We tested 21 children with epilepsy (total IQ > 80; 13 with Childhood epilepsy with centro-temporal spikes, 8 with Panayiotopoulos syndrome (PS); 5-13 years old) compared to a healthy age-matched control group (32 participants). We used the Dynamic Temporal Prediction (DTP) task to investigate how behavioral performance is implicitly shaped by the manipulation of the stimulus occurrence probability over time. We recorded EEG to identify neural markers to differentiate the two groups. SFEC group showed a reduction in accuracy (p = .0013) and response speed (p < .001) as well as an absence of response adjustment (p = .65) in relation to the implicit changes in stimulus probability occurrence, in comparison to the control group. The epilepsy group performance in the DTP showed a significant correlation with the phonemic fluency (r = -0.50) and the Perseverations index of the CPT test (r = 0.53). Finally, children with SFEC did not show the modulation of the contingent negative variation (CNV) evoked potential. Overall, children with SFEC showed poor implicit flexibility compared to a control group. This pattern is individually related to high-level executive function, suggesting to extend neuropsychological assessment to the implicit domain.

Focal Sleep Spindle Deficits Reveal Focal Thalamocortical Dysfunction and Predict Cognitive Deficits in Sleep Activated Developmental Epilepsy

Childhood epilepsy with centrotemporal spikes (CECTS) is the most common focal epilepsy syndrome, yet the cause of this disease remains unknown. Now recognized as a mild epileptic encephalopathy, children exhibit sleep-activated focal epileptiform discharges and cognitive difficulties during the active phase of the disease. The association between the abnormal electrophysiology and sleep suggests disruption to thalamocortical circuits. Thalamocortical circuit dysfunction resulting in pathologic epileptiform activity could hinder the production of sleep spindles, a brain rhythm essential for memory processes. Despite this pathophysiologic connection, the relationship between spindles and cognitive symptoms in epileptic encephalopathies has not been previously evaluated. A significant challenge limiting such work has been the poor performance of available automated spindle detection methods in the setting of sharp activities, such as epileptic spikes. Here, we validate a robust new method to accurately measure sleep spindles in patients with epilepsy. We then apply this detector to a prospective cohort of male and female children with CECTS with combined high-density EEGs during sleep and cognitive testing at varying time points of disease. We show that: (1) children have a transient, focal deficit in spindles during the symptomatic phase of disease; (2) spindle rate anticorrelates with spike rate; and (3) spindle rate, but not spike rate, predicts performance on cognitive tasks. These findings demonstrate focal thalamocortical circuit dysfunction and provide a pathophysiological explanation for the shared seizures and cognitive symptoms in CECTS. Further, this work identifies sleep spindles as a potential treatment target of cognitive dysfunction in this common epileptic encephalopathy.SIGNIFICANCE STATEMENT Childhood epilepsy with centrotemporal spikes is the most common idiopathic focal epilepsy syndrome, characterized by self-limited focal seizures and cognitive symptoms. Here, we provide the first evidence that focal thalamocortical circuit dysfunction underlies the shared seizures and cognitive dysfunction observed. In doing so, we identify sleep spindles as a mechanistic biomarker, and potential treatment target, of cognitive dysfunction in this common developmental epilepsy and provide a novel method to reliably quantify spindles in brain recordings from patients with epilepsy.

Evaluation of auditory spectral resolution abilities in children with benign epilepsy with centrotemporal spikes using spectral temporally modulated ripple test

PURPOSE

Spectral resolution is imperative for complex listening tasks such as understanding speech in the presence of background noise and has a significant role in children, particularly classroom learning. The present study evaluated the auditory spectral resolution abilities of children with Benign epilepsy with centrotemporal spikes (BECTS).

METHOD

This cross-sectional study conducted from August 2017 to March 2020 recruited 23 children with clinical and electrographic features consistent with BECTS as cases. Fifteen age and sex matched typically developing children (TDC) were taken as controls. Spectral resolution abilities were evaluated using the recently developed Spectral temporally modulated Ripple test (SMRT).

RESULTS

The mean age of the cases was 10.63 ± 1.91 years with a slight male preponderance (69%). The mean (±SD) SMRT thresholds in the cases and controls were 5.90 (±1.91) and 7.21 (±1.03) respectively. The auditory spectral resolution threshold measured by SMRT in children with BECTS was observed to be significantly lower when compared to the controls (p of 0.021).

CONCLUSION

Children with BECTS have a lower spectral resolution threshold by SMRT.

The relationship between epilepsy and cognitive function in benign childhood epilepsy with centrotemporal spikes

INTRODUCTION

This study was aimed to explore the relationship between neural network changes in newly diagnosed children with Benign Childhood Epilepsy with Centrotemporal Spikes (BECTS) and cognitive impairment.

METHODS

Children's cognition was evaluated using the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV). Magnetoencephalographic (MEG) data of 18 healthy children and 22 BECTS patients were recorded in order to construct a functional connectivity (FC) network, which was quantified by graph theory (GT).

RESULTS

The mean age of the control group was 7.94 ± 1.89 years, and the mean age of BECTS patients was 8.14 ± 1.73 years. Our results show that the WISC-IV index scores in the BECTS group were significantly lower than those in the control group. Besides, the FC network pattern of BECTS patients changed significantly in the 12-30, 30-80, and 250-500 Hz frequency band. The local functional connections between posterior cingulate cortex (PCC) and frontal lobe varied significantly in 12-30, 80-250, and 250-500 Hz. Our GT analysis shows that the connection strength of BECTS patients increases significantly in the 12-30 Hz frequency band, the path length decreases significantly in the 12-30 Hz and 30-80 Hz frequency bands, with the clustering coefficient decreasing significantly in the 12-30 Hz, 30-80 Hz, and 250-500 Hz frequency bands. Correlation analysis showed that the full-scale IQ (FSIQ) was positively correlated with the 12-30 Hz clustering coefficient, verbal comprehension index (VCI) was positively correlated with the 250-500 Hz clustering coefficient, perceptual reasoning index (PRI) was positively correlated with the 12-30 Hz clustering coefficient, and perceptual reasoning index (PSI) was negatively correlated with the 12-30 Hz path length.

CONCLUSION

There is a trend of cognitive impairment in patients with early BECTS. This trend of cognitive impairment in early BECTS children may be related to the changes in the FC network pattern.

Childhood Epilepsy with Centrotemporal Spikes: Clinical and Neuropsychological Outcomes 5 Years after Remission

Although specific neuropsychological deficits have been recognized during the active phase of epilepsy with centrotemporal spikes (ECTS), the natural cognitive and neuropsychological history after remission has not been elucidated so far. We evaluated the natural cognitive and neuropsychological outcomes five years after disease remission and investigated possible predictors of long-term outcome among socio-demographic and electro-clinical variables. We performed an observational cross-sectional study. Electro-clinical characteristics during the active phase of epilepsy, as well as antiepileptic treatment and premorbid neurodevelopmental concerns were reviewed for 70 patients. At least five years after epilepsy remission, all patients were contacted, and 46 completed a structured questionnaire about patients’ current education and academic skills, general health, and parents’ socio-economic status. Among them, 23 patients underwent an ad hoc cognitive and neuropsychological protocol and emotional-behavioral assessment. Chi-square tests and t-tests were carried out to define the role of putative predictors of neuropsychological outcomes. Mean cognitive and neuropsychological performances appeared to be overall adequate, except for the dictation. Positive family history for epilepsy (p = 0.01769) and familial socioeconomic status (mother’s schooling (p = 0.04169), father’s schooling (p = 0.01939), mother’s income (p = 0.0262), father’s income (p = 0.01331)) were identified as predictors of outcomes. Our data suggest that ECTS with typical electro-clinical features depicts an overall preserved cognitive and neuropsychological long-term outcome. We suggest particular attention should be paid to patients with socio-economic disadvantage and familial history of epilepsy, as they may experience worse neurocognitive post-morbid performances.

The relationship between neuromagnetic activity and cognitive function in benign childhood epilepsy with centrotemporal spikes

PURPOSE

Our aim was to explore the pathophysiological mechanism of cognitive function changes in early untreated children with benign childhood epilepsy with centrotemporal spikes (BECTS).

METHODS

Magnetoencephalography (MEG) was performed in 33 children with BECTS and 18 healthy children. Wechsler Intelligence Scale for Children, fourth edition (WISC-IV) was used to divide children with BECTS into two groups. Normal cognitive function was defined as a full-scale intelligence quotient (FSIQ) of >80, while decreased cognitive function was defined as a FSIQ of <80. Accumulated source imaging was used to evaluate the neuromagnetic source activity in multifrequency bands.

RESULTS

Of the 33 patients with early untreated BECTS, a total of 17 had a FSIQ of <80 and 16 had FSIQ of >80. The course of epilepsy and number of seizures in the FSIQ <80 group were higher than that in the FSIQ >80 group. Our MEG results showed that in the 4-8 Hz frequency band, both patient groups had inactivation of the posterior cingulate cortex (PCC) region compared with the healthy control group. In the 30-80 Hz frequency band, the FSIQ <80 group showed inactivation of the PCC region compared with both the healthy control group and the FSIQ >80 group. In the 80-250 Hz frequency band, the FSIQ <80 group had inactivated of the medial frontal cortex (MFC) region compared with the healthy control group. In the 30-80 Hz frequency band, the strength of neuromagnetic source in patients with BECTS with FSIQ <80 was higher than that in the FSIQ >80 group and the healthy control group.

CONCLUSIONS

The magnetic source inactivation of the MFC and PCC regions during the interictal time may be the reason for cognitive decline in early untreated children with BECTS. Children with BECTS with cognitive decline had a longer course of epilepsy and more seizures. The magnetic source localization in the 4-8 Hz frequency band may be a new imaging marker for the diagnosis of new BECTS.

ADHD and ADHD-related neural networks in benign epilepsy with centrotemporal spikes: A systematic review

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) and benign epilepsy with centrotemporal spikes (BECTS or rolandic epilepsy) present with a very high level of comorbidity. We aimed to review the existing literature focusing on two aspects: the possible role of epileptic activity in the damage of ADHD-related neural networks and the clinical approach to patients presenting with both conditions.

MATERIAL AND METHODS

A systematic review was performed using Sapienza Library System and PubMed. The following search terms have been considered: attention networks, ADHD, attention systems, rolandic epilepsy, benign epilepsy with centrotemporal spikes, centrotemporal spikes epilepsy, and focal epilepsy in children. The target population consisted of patients under 18 years of age diagnosed with either BECTS and ADHD or healthy controls.

RESULTS

Nine case-control and cohort studies have been selected. The reported prevalence of ADHD in patients with BECTS was around 60%. No clinical correlation was found between the medical records and the presence of ADHD in patients with BECTS, if not due to febrile convulsion (FC). One study showed higher levels of bilateral discharges in patients with severe ADHD. The negative influence of the age at onset of seizures was demonstrated on attention but not on intelligence quotient (IQ). Moreover, the frequency of seizures and the occurrence of discharges during nonrapid eye movement (NREM) sleep were correlated to attention impairment. From a neurobiological point of view, functional connectivity in patients with BECTS and ADHD appears to be disrupted. Two studies reported a specific impairment in selective visual attention, while one study underlined a decreased activation of the dorsal attention network (DAN). Two different studies found that patients with BECTS and comorbid ADHD presented with altered thickness in their magnetic resonance imaging (MRI) scans in the cortical and subcortical regions (including the frontal lobes, lingual-fusiform cortex, cuneus and precuneus, limbic area and pericalcarine cortex among others). This might explain the cognitive and behavioral symptoms such as poor selective visual attention, speech disturbance, and impulsivity.

CONCLUSIONS

Despite BECTS being considered to have a relative benign course, many studies have documented cognitive and/or behavioral problems in patients diagnosed with this type of epilepsy. In particular, children affected by rolandic epilepsy should receive a complete neuropsychological evaluation at seizure onset considering the high rate of comorbidity with ADHD. A further investigation of the common pathogenic substrate is desirable to better orientate the clinical and therapeutic interventions applied.

Persistent abnormalities in Rolandic thalamocortical white matter circuits in childhood epilepsy with centrotemporal spikes

OBJECTIVE

Childhood epilepsy with centrotemporal spikes (CECTS) is a common, focal, transient, developmental epilepsy syndrome characterized by unilateral or bilateral, independent epileptiform spikes in the Rolandic regions of unknown etiology. Given that CECTS presents during a period of dramatic white matter maturation and thatspikes in CECTS are activated during non-rapid eye movement (REM) sleep, we hypothesized that children with CECTS would have aberrant development of white matter connectivity between the thalamus and the Rolandic cortex. We further tested whether Rolandic thalamocortical structural connectivity correlates with spike rate during non-REM sleep.

METHODS

Twenty-three children with CECTS (age = 8-15 years) and 19 controls (age = 7-15 years) underwent 3-T structural and diffusion-weighted magnetic resonance imaging and 72-electrode electroencephalographic recordings. Thalamocortical structural connectivity to Rolandic and non-Rolandic cortices was quantified using probabilistic tractography. Developmental changes in connectivity were compared between groups using bootstrap analyses. Longitudinal analysis was performed in four subjects with 1-year follow-up data. Spike rate was quantified during non-REM sleep using manual and automated techniques and compared to Rolandic connectivity using regression analyses.

RESULTS

Children with CECTS had aberrant development of thalamocortical connectivity to the Rolandic cortex compared to controls (P = .01), where the expected increase in connectivity with age was not observed in CECTS. There was no difference in the development of thalamocortical connectivity to non-Rolandic regions between CECTS subjects and controls (P = .19). Subjects with CECTS observed longitudinally had reductions in thalamocortical connectivity to the Rolandic cortex over time. No definite relationship was found between Rolandic connectivity and non-REM spike rate (P > .05).

SIGNIFICANCE

These data provide evidence that abnormal maturation of thalamocortical white matter circuits to the Rolandic cortex is a feature of CECTS. Our data further suggest that the abnormalities in these tracts do not recover, but are increasingly dysmature over time, implicating a permanent but potentially compensatory process contributing to disease resolution.

Factors associated with motor dexterity on the grooved pegboard test in a Lebanese sample

The Grooved Pegboard Test (GPT) is a cognitive test used to assess patients' manual dexterity, rapid visual-motor coordination and psychomotor speed. Studies have shown that performance on the GPT is associated to cognitive functions and examinee's demographics; however, none of which involved Arab populations. The present study aims to explore motor dexterity as measured by the GPT and its relationship to intellectual abilities, age, gender and education in a sample of Lebanese individuals. We reviewed the charts of 330 patients who were administered the GPT as part of larger cognitive batteries in an outpatient diagnostic center in Beirut, Lebanon between September 2013 and September 2016. Results from this sample suggest that a higher Full Scale IQ, and an older age contribute to a better performance on the GPT, whereas gender and grade level are not significant predictors of performance. Results also show a significant difference between the performance of patients diagnosed with a Developmental Coordination Disorder and patients with no neurodevelopmental diagnosis.

Temporal trends in incidence of Rolandic epilepsy, prevalence of comorbidities and prescribing trends: birth cohort study

OBJECTIVE

To examine temporal trends in incidence of Rolandic epilepsy (RE), prevalence of comorbidities and antiepileptic drug (AED) prescribing patterns.

DESIGN

Retrospective cohort study.

SETTING

The UK.

PATIENTS

Children aged 0-16 years born 1994-2012 were followed from birth until September 2017, transfer to another general practitioner practice or death or practice withdrawal from The Health Improvement Network (THIN), whichever occurred first.

MAIN OUTCOME MEASURES

Incidence of RE, prevalence of comorbidity and AED prescribing patterns. Read codes for comorbidities and AEDs were adapted from other UK population-based epilepsy studies.

RESULTS

There were 379 children with first RE event recorded between 2000 and 2014 from active THIN practices with available mid-year population counts. Crude annual incidence across all years was 5.31/100 000 (95% CI 4.81 to 5.88). There was no significant time trend in adjusted incidence rate ratios (aIRR) (0.99/year, 95% CI 0.96 to 1.02). Males had higher aIRR (1.48, 95% CI 1.20 to 1.82) as did children aged 6-8 and 9-11 years compared with 4-5 years (aIRR 2.43, 95% CI 1.73 to 3.40; aIRR 2.77, 95% CI 1.97 to 3.90, respectively). There was recorded comorbidity in 12% with 6% with a recorded diagnosis of pervasive developmental disorder. Half of children with RE had a record of being prescribed AEDs.

CONCLUSIONS

UK incidence of RE has remained stable with crude incidence of 5/100 000/year. Carers and clinicians need to be aware that comorbidities may exist, particularly pervasive developmental disorders. Carbamazepine is consistently the most commonly prescribed AED for RE in the UK.

Sleep architecture and homeostasis in children with epilepsy: a neurodevelopmental perspective

Although the influence of sleep on epilepsy has long been recognized, this relationship has yet to be fully exploited to benefit patients. The past decade has seen significant advances in understanding paediatric sleep, providing a framework by which to properly evaluate the sleep of children with epilepsy, which itself has been subject to increasing scrutiny. The role of sleep in learning and the potential for interictal discharges to disrupt sleep-related memory consolidation provide a novel perspective for understanding the association of childhood epilepsy with a high rate of intellectual disability. In this review, I outline the evolution of sleep duration, architecture, and homeostasis across childhood, relating this to the development of cognitive functions. I describe how these may be disrupted or preserved in children with epilepsy; in particular, collating data from polysomnography. Finally, I explore how sleep may, in the future, be modulated to improve cognitive outcome in these patients. WHAT THIS PAPER ADDS: Children with epilepsy have less rapid eye movement sleep than controls, but this improves with seizure cessation. Deep or slow-wave sleep is highly conserved in children with epilepsy. Sleep homeostasis may be disrupted either at a local or global level by the presence of interictal epileptiform discharges.

The natural history of seizures and neuropsychiatric symptoms in childhood epilepsy with centrotemporal spikes (CECTS)

OBJECTIVE

Childhood epilepsy with centrotemporal spikes (CECTS) (formally benign epilepsy with centrotemporal spikes, BECTS) is a common childhood epilepsy syndrome characterized by psychiatric, behavioral, and cognitive abnormalities and self-limited seizures. Although CECTS is one of the most well-characterized electroclinical epilepsy syndromes, the natural history of neuropsychiatric outcomes is poorly understood. We report the psychiatric, behavioral, and cognitive profiles over the course of disease from a large, prospectively-enrolled, longitudinal cohort of children with CECTS. We further characterize the detailed seizure course and test the relationship between several proposed risk factors and neuropsychiatric and seizure outcomes in these children.

METHODS

Patients diagnosed with CECTS were enrolled as part of a community-based study and followed from diagnosis through disease resolution (16.0 ± 3.1 years, N = 60). Twenty sibling controls were also recruited. We report the natural history of premorbid neuropsychiatric concerns, postmorbid neuropsychiatric diagnoses, long-term neuropsychological performance, seizure course, antiseizure medication (ASM) treatment response, and the relationship between duration seizure-free and remission. Age at onset and premorbid neuropsychiatric concerns were tested as predictors of seizure count, epilepsy duration, postmorbid neuropsychiatric diagnoses, and long-term neuropsychological performance. Antiseizure medication treatment duration, seizure count, and epilepsy duration were tested as predictors of postmorbid neuropsychiatric diagnoses and long-term neuropsychological performance.

RESULTS

Children with CECTS had a high incidence of ADD/ADHD symptoms (18.3%) or learning difficulties (21.7%) before diagnosis. New or persistent ADHD (20%), mood disorders (23.6%), learning difficulties (14.5%), and behavioral disorders (7.3%) were common after CECTS diagnosis. At 9-year follow-up, performance on formal neuropsychological testing was comparable to population statistics and sibling controls. More than two-thirds of treated children experienced at least one seizure during treatment. Most children (61.7%) had entered terminal resolution after 12 months seizure-free. Among all children, for each month seizure-free, there was a 6-7% increase in the probability of achieving terminal remission (p < 1e-10). The presence of a premorbid neurodevelopmental concern predicted a longer epilepsy duration (p = 0.02), higher seizure count (p = 0.02), and a postmorbid psychiatric or neurodevelopmental diagnosis (p = 0.002). None of the tested features predicted long-term neuropsychological performance.

SIGNIFICANCE

Children are at high risk of neuropsychiatric symptoms along the course of the disease in CECTS, however, long-term cognitive performance is favorable. The majority of children had a seizure while being treated with ASMs, suggesting that CECTS is not as pharmacoresponsive as assumed or that treatment approaches are not optimized. Among treated and untreated children, future seizure-risk can be estimated from duration seizure-free. The presence of a premorbid neuropsychiatric concern predicted a more severe disease course in CECTS.

Impact of epilepsy on language and discourse: Two self-limited focal epileptic syndromes of childhood

Self-limited focal epilepsy with centro-temporal spikes, also known as Rolandic epilepsy (RE), is a well-established focal epilepsy of childhood, characterized with language impairment. To investigate the relationship between language deficits and clinical parameters of self-limited focal epilepsies of childhood (SFEC), 21 patients with RE, 10 patients with childhood occipital epilepsy of Gastaut type (COE-G) (another SFEC that is not typically associated with language impairment), and 31 healthy controls were recruited. A broad panel of language tests also including narration sample was administered, and clinical features were documented. The language was significantly impaired in both RE and COE-G. Patients with COE-G showed worse scores than patients with RE in subtests measuring semantic functions. Clinical parameters were not associated with impaired language domains. Language impairment is experienced in different types of SFEC, emphasizing the broad representation of the language network. In SFEC, recent activity of epilepsy does not affect the severity of language dysfunction.

Mapping the Effect of Interictal Epileptic Activity Density During Wakefulness on Brain Functioning in Focal Childhood Epilepsies With Centrotemporal Spikes

Childhood epilepsy with centrotemporal spikes (CECTS) is the most common type of “self-limited focal epilepsies.” In its typical presentation, CECTS is a condition reflecting non-lesional cortical hyperexcitability of rolandic regions. The benign evolution of this disorder is challenged by the frequent observation of associated neuropsychological deficits and behavioral impairment. The abundance (or frequency) of interictal centrotemporal spikes (CTS) in CECTS is considered a risk factor for deficits in cognition. Herein, we captured the hemodynamic changes triggered by the CTS density measure (i.e., the number of CTS for time bin) obtained in a cohort of CECTS, studied by means of video electroencephalophy/functional MRI during quite wakefulness. We aim to demonstrate a direct influence of the diurnal CTS frequency on epileptogenic and cognitive networks of children with CECTS. A total number of 8,950 CTS (range between 27 and 801) were recorded in 23 CECTS (21 male), with a mean number of 255 CTS/patient and a mean density of CTS/30 s equal to 10,866 ± 11.46. Two independent general linear model models were created for each patient based on the effect of interest: “individual CTS” in model 1 and “CTS density” in model 2. Hemodynamic correlates of CTS density revealed the involvement of a widespread cortical–subcortical network encompassing the sensory-motor cortex, the Broca's area, the premotor cortex, the thalamus, the putamen, and red nucleus, while in the CTS event-related model, changes were limited to blood–oxygen-level-dependent (BOLD) signal increases in the sensory-motor cortices. A linear relationship was observed between the CTS density hemodynamic changes and both disease duration (positive correlation) and age (negative correlation) within the language network and the bilateral insular cortices. Our results strongly support the critical role of the CTS frequency, even during wakefulness, to interfere with the normal functioning of language brain networks.

BECTS Substate Classification by Granger Causality Density Based Support Vector Machine Model

Objectives: To investigate the performance of substate classification of children with benign epilepsy with centrotemporal spikes (BECTS) by granger causality density (GCD) based support vector machine (SVM) model.

Methods: Forty-two children with BECTS (21 females, 21 males; mean age, 8.6 ± 1.96 years) were classified into interictal epileptic discharges (IEDs; 11 females, 10 males) and non-IEDs (10 females, 11 males) substates depending on presence of central-temporal spikes or not. GCD was calculated on four metrics, including inflow, outflow, total-flow (inflow + outflow) and int-flow (inflow – outflow) connectivity. SVM classifier was applied to discriminate the two substates.

Results: The Rolandic area, caudate, dorsal attention network, visual cortex, language networks, and cerebellum had discriminative effect on distinguishing the two substates. Relative to each of the four GCD metrics, using combined metrics could reach up the classification performance (best value; AUC, 0.928; accuracy rate, 90.83%; sensitivity, 90%; specificity, 95%), especially for the combinations with more than three GCD metrics. Specially, combined the inflow, outflow and int-flow metric received the best classification performance with the highest AUC value, classification accuracy and specificity. Furthermore, the GCD-SVM model received good and stable classification performance across 14 dimension reduced data sets.

Conclusions: The GCD-SVM model could be used for BECTS substate classification, which might have the potential to provide a promising model for IEDs detection. This may help assist clinicians for administer drugs and prognosis evaluation.

Analysis of serial electroencephalographic predictors of seizure recurrence in Rolandic epilepsy

PURPOSE

We aimed to assess the relationship between electroencephalography (EEG) markers and seizure recurrence in cases with benign epilepsy with centrotemporal spikes (BECT) in a long-term follow-up study.

METHODS

We analyzed the data of 52 children with BECT who were divided into 2 groups: the isolated group and recurrence group. The clinical profiles and initial/serial visual EEG recordings of both groups were evaluated. The entire follow-up period ranged from 12 to 65 months.

RESULTS

None of the clinical characteristics differed between the 2 groups. Serial EEGs showed that the appearance of Rolandic spikes in the frontal region was more prevalent in the recurrence group. Moreover, a significant correlation was found between bilateral asynchronous discharges and seizure recurrence. However, on initial EEG of these patients, neither of the EEG features exhibited statistical significance.

CONCLUSION

The presence of frontal focus and bilateral asynchrony appeared to be hallmarks of BECT patients with higher risk for seizure recurrence.

Functional and Structural Network Disorganizations in Typical Epilepsy With Centro-Temporal Spikes and Impact on Cognitive Neurodevelopment

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 remodeling 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 interictal epileptic spikes (IES) in the epileptogenic zone and in remote networks in ECTS. Over the epileptogenic zone, the literature demonstrates changes in term of neuronal activity and synchronization, which are effective several hundred milliseconds before the IES. In the same time window, functional changes are also observed in bilateral distant networks, notably in the frontal and temporal lobes. Effective connectivity demonstrates that the epileptogenic zone constitutes the key area at the origin of IES propagation toward 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.

Cognitive profile in BECTS treated with levetiracetam: A 2-year follow-up

INTRODUCTION

Benign epilepsy with centrotemporal spikes (BECTS) is a common epileptic syndrome in childhood, characterized by brief and infrequent partial motor seizures, with or without generalization and mostly recurring during sleep. Because of its favorable efficacy, tolerability, and safety profile, levetiracetam (LEV) monotherapy is often administered in these patients. Long-term effects of LEV therapy and its influence on cognitive functions remain controversial.

PURPOSE

This evaluated the changes in the cognitive profile of children with BECTS treated with LEV monotherapy for 2 years, compared with a control group of children with specific learning disabilities.

METHOD

Our patient cohort included 20 children aged 8-14 years diagnosed as having BECTS and administered LEV monotherapy and 10 age/sex-matched controls with specific learning disabilities. All participants underwent a standardized test for assessing cognitive profile (Wechsler Intelligence Scale for Children - Fourth Edition [WISC-IV]) before drug therapy and after 2 years of treatment. Average LEV blood level and electroencephalographic (EEG) recordings were periodically monitored. Several factors such as age, sex, response to therapy, and EEG pattern changes were considered. Statistical analysis was performed using Student's t-test for paired and independent samples. p < 0.05 was considered statistically significant.

RESULTS

Children administered LEV for 24 months showed a mild but statistically significant improvement in overall cognitive abilities. Verbal skills, visual-perceptual reasoning, working memory, and processing speed showed slight but significant improvement. In the control group, cognitive profile remained substantially unchanged at 2-year follow-up.

CONCLUSIONS

Not only do our data suggest a nonworsening of the cognitive profile in BECTS with LEV but, on the contrary, cognitive scores also improved over time, unlike the control group.

Dysmature superficial white matter microstructure in developmental focal epilepsy

Benign epilepsy with centrotemporal spikes is a common childhood epilepsy syndrome that predominantly affects boys, characterized by self-limited focal seizures arising from the perirolandic cortex and fine motor abnormalities. Concurrent with the age-specific presentation of this syndrome, the brain undergoes a developmentally choreographed sequence of white matter microstructural changes, including maturation of association u-fibres abutting the cortex. These short fibres mediate local cortico-cortical communication and provide an age-sensitive structural substrate that could support a focal disease process. To test this hypothesis, we evaluated the microstructural properties of superficial white matter in regions corresponding to u-fibres underlying the perirolandic seizure onset zone in children with this epilepsy syndrome compared with healthy controls. To verify the spatial specificity of these features, we characterized global superficial and deep white matter properties. We further evaluated the characteristics of the perirolandic white matter in relation to performance on a fine motor task, gender and abnormalities observed on EEG. Children with benign epilepsy with centrotemporal spikes (n = 20) and healthy controls (n = 14) underwent multimodal testing with high-resolution MRI including diffusion tensor imaging sequences, sleep EEG recordings and fine motor assessment. We compared white matter microstructural characteristics (axial, radial and mean diffusivity, and fractional anisotropy) between groups in each region. We found distinct abnormalities corresponding to the perirolandic u-fibre region, with increased axial, radial and mean diffusivity and fractional anisotropy values in children with epilepsy (P = 0.039, P = 0.035, P = 0.042 and P = 0.017, respectively). Increased fractional anisotropy in this region, consistent with decreased integrity of crossing sensorimotor u-fibres, correlated with inferior fine motor performance (P = 0.029). There were gender-specific differences in white matter microstructure in the perirolandic region; males and females with epilepsy and healthy males had higher diffusion and fractional anisotropy values than healthy females (P ≤ 0.035 for all measures), suggesting that typical patterns of white matter development disproportionately predispose boys to this developmental epilepsy syndrome. Perirolandic white matter microstructure showed no relationship to epilepsy duration, duration seizure free, or epileptiform burden. There were no group differences in diffusivity or fractional anisotropy in superficial white matter outside of the perirolandic region. Children with epilepsy had increased radial diffusivity (P = 0.022) and decreased fractional anisotropy (P = 0.027) in deep white matter, consistent with a global delay in white matter maturation. These data provide evidence that atypical maturation of white matter microstructure is a basic feature in benign epilepsy with centrotemporal spikes and may contribute to the epilepsy, male predisposition and clinical comorbidities observed in this disorder.

Autism spectrum disorder and attention-deficit/hyperactivity disorder-related symptoms in benign childhood epilepsy with centrotemporal spikes: A prospective case-control study

BACKGROUND

Benign childhood epilepsy with centrotemporal spikes (BECTS), one of the most common idiopathic epilepsy syndromes in children, has been associated with neuropsychological problems.

PURPOSE

The objective of this study was to investigate the frequency of symptoms related to comorbid neurodevelopmental disorders, the autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) in children with typical BECTS, and to identify corresponding risk factors.

METHODS

Children and adolescents with typical BECTS aged 6-16 years were included in the study period from January 1, 2017, to December 31, 2017. Children with atypical presentations of BECTS, other neurological disorders, and preexisting neuropsychiatric disorders were excluded. The ASD and ADHD were assessed by the Social Communication Questionnaire (SCQ) and the Turgay Diagnostic and Statistical Manual of Mental Disorders - 4th Edition - Disruptive Behavior Disorders Rating Scale (T-DSM-IV-S), respectively. Patients' scores were compared with those of healthy subjects. Correlation analyses were performed to evaluate the association between the age at seizure onset, the total number of seizures and the SCQ and T-DSM-IV-S scores.

RESULTS

Fifty-eight children with BECTS and 60 healthy children participated in the study. The total SCQ score, the SCQ reciprocal social interaction score, and the SCQ communication score significantly differed between children with BECTS and the control group (p = 0.001, p < 0.001, p = 0.001, respectively). The total ADHD score was significantly different between patients and controls (p < 0.001). A significant difference was observed between patients and controls in terms of the T-DSM-IV-S hyperactivity-impulsivity score and the T-DSM-IV-S inattention score (p = 0.012, p < 0.001, respectively). The age at seizure onset was significantly correlated with the total SCQ score (p = 0.03). The Spearman's correlation coefficient was 0.352 for the total SCQ score, indicating a positive association between the age at seizure onset and the total SCQ score.

CONCLUSION

Children with typical BECTS may have an increased risk of suffering from symptoms of ASD and ADHD. Children with late onset of seizures may be more likely to develop neuropsychological disturbances regarding ASD and ADHD.

Delayed cortical maturation at the centrotemporal brain regions in patients with benign childhood epilepsy with centrotemporal spikes (BCECTS)

Benign childhood epilepsy with centrotemporal spikes (BCECTS) is an epilepsy syndrome commonly found in child and adolescent. Although the prognosis is mostly favorable as long as the seizure is well controlled. However, they are often suffering from the cognitive and behavioral problems which might be the consequences of the initial insults. It is still not clear whether the initial epileptiform discharges has long term impact on the resting-state brain activities at later ages. This study investigated the resting-state brain activities in BCECTS patients with clinical seizure remission stage (n = 16; 11 males) and compared with the non-epileptic, age-matched control subjects. Quantitative electroencephalography (qEEG) revealed a significantly higher absolute power of the theta and alpha waves in BCECTS patients with clinical seizure remission as compared with the non-epileptic control subjects. Interestingly, the differences were observed mainly over the centrotemporal electrodes which are the common sites of the initial epileptiform discharges. The differences were more significant in patients with bilateral epileptiform discharges than those with the unilateral epileptic activities. Typically, the brain wave power continuously decreases with increasing ages. Therefore, higher absolute powers of the brain waves indicate more delayed in cortical maturation compared with the non-epileptic control group. These findings indicated that BCECTS patients have delay cortical maturation at the centrotemporal brain regions even at the clinical seizure remission phase.

Epilepsy as a derailment of sleep plastic functions may cause chronic cognitive impairment - A theoretical review

We report on a peculiar way of chronic cognitive impairment associated with interictal epileptic activity during NREM sleep. We review three major groups of epilepsy: mesiotemporal epilepsy (MTLE) involving the epileptic derailment of the hippocampal declarative memory system; childhood developmental epileptic encephalopathies; and the spectrum disorders of the perisylvian communication network with the centrotemporal spike phenomenon, overarching child- and adulthood epilepsies, totaling up the majority of epilepsies in childhood. We outline high impact research-lines on the cognitive harm of epilepsy; causing specific or global cognitive decline through its interference with sleep plastic functions. We highlight the key role of interictal activity in the development of cognitive impairment and the fact that we are unarmed against this harm, antiepileptic pharmaco-therapy being ineffective against the interictal process marked by spikes and high frequency oscillations.

Strong relationship between NREM sleep, epilepsy and plastic functions - A conceptual review on the neurophysiology background

The aim of this review is to summarize and discuss the strong bond between NREM sleep and epilepsy underlain by the shared link and effect on brain plasticity. Beyond the seizure occurrence rate, sleep relatedness may manifest in the enhancement of interictal epileptic discharges (spikes and pathological ripples). The number of the discharges as well as their propagation increase during NREM sleep, unmasking the epileptic network that is hidden during wakefulness. The interictal epileptic discharges associate with different sleep constituents (sleep slow waves, spindling and high frequency oscillations); known to play essential role in memory and learning. We highlight three major groups of epilepsies, in which sleep-related plastic functions suffer an epileptic derailment. In absence epilepsy mainly involving the thalamo-cortical system, sleep spindles transform to generalized spike-wave activity. In mesio-temporal epilepsy affecting the hippocampal declarative memory system, the sharp wave ripples derail to dysfunctional epileptic oscillations (spikes and pathological ripples). Idiopathic childhood epilepsies affecting the perisylvian network may progress to catastrophic status electricus during NREM sleep. In these major epilepsies, NREM sleep has a pivotal role in the development and course of the disorder. Epilepsy is born in-, and exhibits its pathological properties during NREM sleep. Interictal discharges are important causative agents in this process.

The Value of Electroencephalogram in Assessing Children With Speech and Language Impairments

Purpose We sought to estimate the prevalence of isolated epileptiform activity (IEA) in children with speech and language impairments and discuss the utility of an electroencephalogram (EEG) in assessing these children. Method We conducted a systematic review and searched for eligible studies in 8 databases. All languages were included, and meta-analyses were performed. Results We found 55 prevalence estimates (8 with control group). The odds of having IEA were 6 times greater for children with speech and language impairments than for typically developing children. The overall pooled prevalence of IEA was 27.3%. A wide variation between the prevalence estimates was, to a certain degree, explained by type of impairment (8.1% in speech impairments, 25.8% in language impairments, and 51.5% in language regression). Sleep EEGs detected a significantly higher prevalence than awake EEGs. Although the presence of epilepsy gave a significantly higher prevalence than if epilepsy was not present, 33.5% of children with language impairment but without epilepsy were found to have IEA in sleep EEGs. Conclusions This systematic review shows that IEA is 6 times more prevalent in children with speech and language impairment than in typically developing children. However, the prevalence rates vary to a great extent. Uncovering IEA will, in addition to information from other clinical assessments, provide a more comprehensive understanding of the child's impairments. We argue that, although EEG is of questionable value when assessing children with speech impairments, sleep EEG could be valuable when assessing children with language impairments and, in particular, children who experience language regression.