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Purpose Polymicrogyria (PMG), although the most common brain malformation, represents a low percentage among patients operated on for epilepsy. In cases of hemispheric PMG, electrical status epilepticus during slow sleep (ESESS) may occur leading to an aggravation of the neurological condition and a risk of drug resistance. In such cases, surgical treatment can be offered. Methods From a population of 230 children who underwent hemispherotomy for epilepsy, we retrospectively reviewed the patients with unilateral PMG and drug-resistant ESESS focusing on clinical charts, electrophysiological data and post-surgical outcome. Results Eighteen patients were operated on at a mean age of 7.2 years. The average age was 2 years at seizure onset and 4.4 years at diagnosis of ESESS. All the patients preoperatively had some degree of developmental delay associated with a hemiparesis. During ESESS all of them evidenced a cognitive decline and eight experienced a worsening of the hemiparesis; ESESS was resistant to at least three antiepileptic drugs. The outcome of epilepsy, with a mean follow-up of 12.8 years showed that ESESS disappeared in all patients while 16 of 18 became seizure-free. An improvement of behavior and cognitive condition was observed in all. Conclusion Hemispherotomy can be helpful in patients with drug-resistant ESESS and hemispheric PMG while keeping in mind that more often an accurate medical treatment can be sufficient. The main benefit of surgery is to definitively stop the seizures and to withdraw the medical treatment while keeping in mind the risk of motor aggravation.

Objective We describe the evolution of the electroclinical picture of patients with different types of self-limited epilepsy of childhood (SLEC) occurring at the same or at different times with or without atypical evolutions as well as patients with SLEC associated with childhood absence epilepsy (CAE). Material and methods A multicenter, retrospective, descriptive study was conducted evaluating patients with SLEC who had focal seizures of different types of SLEC including atypical evolutions as well as SLEC associated with absence epilepsy seen at eight Argentinian centers between April 2000 and April 2019. Of 7705 patients with SLEC, aged between 2 and 14 years (mean, 7.5 years), of whom 2013 were female and 5692 male (ratio, 1:2.8), 5068 patients had SLECTS, 2260 patients had self-limited childhood occipital epilepsy Panayiotopoulos type (SLE-P), 356 had self-limited childhood occipital epilepsy Gastaut type (SLE-G), and 21 had self-limited epilepsy with affective seizures (SLEAS). Electroclinical features typical of more than one SLEC syndrome were recognized in 998 (13 %) children. Results We recognized three well-defined groups of patients. The most frequent association was SLE-P and SLECTS, the paradigmatic type, but associations of SLE-P and SLE-G, SLECTS and SLE-G, and SLEAS and SLE-P or SLECTS were also recognized. The second-most-common association was SLEC and an atypical evolution. In this group, the most frequent combination was SLECTS with its atypical evolution, opercular status epilepticus, epileptic encephalopathy with continuous spike‐and‐waves during slow sleep, or Landau-Kleffner syndrome. SLE-P and SLE-G associated with an atypical evolution were also identified. The third, less-frequent group had SLECTS, SLE-P, or SLE-G associated with CAE. These cases support the concept that the different types of SLEC are part of a self-limited childhood seizure susceptibility syndrome. Conclusion Our study demonstrated that 13 % of our patients with SLEC have with different types of SLEC occurring at the same or at different times with or without atypical evolutions - i.e. CSWSS - as well as patients with SLEC associated with CAE, supporting the concept of the self-limited childhood seizure susceptibility syndrome.

Objective It is argued that early and adequate treatment of electrical status epilepticus in sleep (ESES) is essential to preserve cognitive functions and possibly recovering lost skills. Although antiepileptic drugs (AEDs) are effective in ESES, there is not much experience in the use of sulthiame. In this study, we aimed to examine the efficiency and tolerability of sulthiame in ESES. Methods The data of 39 patients diagnosed as ESES and who received sulthiame as an additional treatment between 2016 and 2020 were reviewed retrospectively. Electroencephalographic (EEG) findings and seizure rates were compared before and after the sulthiame treatment. Results The mean age was 8.5 ± 4.1 (1.5–16 years). Nine out of 39 patients had benign childhood focal epilepsies. Structural causes were identified in 13 patients. The mean duration of sulthiame use was 32.5 ± 13.7 months. After sulthiame treatment, 25 patients (64.1%) were seizure free, and 8 (20.5%) had more than a 50% decrease in seizure frequency. The mean seizure-free time after the sulthiame treatment was 27.8 ± 17.9 months. Nineteen patients (48.7%) had complete, and nine patients (23.1%) had partial EEG improvement. Complete seizure control was significantly higher in benign focal epilepsy of childhood (p = 0.01). Significant neurocognitive and behavioral recovery, improvement in school performance was observed following sulthiame treatment (p Conclusion Sulthiame was found to be effective in seizure control and EEG improvement in ESES. We think that the use of sulthiame alone can be a good choice with high efficacy and tolerability in ESES.

In young adults, memory consolidation during sleep is supported by a time-coordinated interplay of sleep spindles and slow oscillations. However, given tremendous developmental changes in sleep spindle and slow oscillation morphology, it remains elusive whether the same mechanisms as identified in young adults are comparably functional across childhood. Here, we characterise slow and fast sleep spindles and their temporal coupling to slow oscillations in 24 pre-school children. Further, we ask whether slow and fast sleep spindles and their modulation during slow oscillations are similarly associated with behavioural indicators of declarative memory consolidation as suggested from adult literature. Employing a development-sensitive, individualised approach, we reliably identify an inherent, development-specific fast sleep spindle type, though nested in the adult-like slow sleep spindle frequency range, along with a dominant slow sleep spindle type. Further, we provide evidence for the modulation of fast sleep spindles during slow oscillations, already in pre-school children. However, the temporal coordination between fast sleep spindles and slow oscillations is weaker and less precise than expected from adult research. While we do not find evidence for a critical contribution of the pattern of fast sleep spindle modulation during slow oscillations for memory consolidation, crucially, both inherent slow and fast sleep spindles separately are differentially related to sleep-associated consolidation of items of varying quality. While a higher number of slow sleep spindles is associated with stronger maintenance of medium-quality memories, more fast sleep spindles are linked to higher gain of low-quality items. Our results provide evidence for two functionally relevant inherent sleep spindle types in pre-school children despite not fully matured sleep spindle - slow oscillation coupling.

Encephalopathy related to Status Epilepticus during slow Sleep (ESES) is an age-dependent syndrome characterized by the appearance of neuropsychological and behavioral disorders associated with extreme activation of epileptic activity during sleep. The major goal of therapy in ESES is to prevent neuropsychological deficits. Effective therapy to reduce seizures and resolve the EEG pattern of status epilepticus during sleep (SES) may be crucial to improve long-term prognosis. However, whether to improve neurodevelopmental deficits by suppressing or eliminating SES remains unknown. The purpose of this article is to review current therapeutic options in ESES, in order to provide better alternatives. Treatment options consist of antiepileptic drugs, steroids, immunoglobulins, the ketogenic diet, and surgery. Maybe therapy targeted mechanisms can be developed with deep insight into the etiology of ESES.

Objective/Background Massive changes in brain morphology and function in the first years of life reveal a postero-anterior trajectory of cortical maturation accompanied by regional modifications of NREM sleep. One of the most sensible marker of this maturation process is represented by electroencephalographic (EEG) activity within the frequency range of sleep spindles. However, direct evidence that these changes actually reflect maturational modifications of fast and slow spindles still lacks. Our study aimed at answering the following questions: 1. Do cortical changes at 11.50 Hz frequency correspond to slow spindles? 2. Do fast and slow spindles show different age trajectories and different topographical distributions? 3. Do changes in peak frequency explain age changes of slow and fast spindles? Patients/Methods We measured the antero-posterior changes of slow and fast spindles in the first 60 min of nightly sleep of 39 infants and children (0–48 mo.). Results We found that (A) changes of slow spindles from birth to childhood mostly affect frontal areas (B) variations of fast and slow spindles across age groups go in opposite direction, the latter progressively increasing across ages; (C) this process is not merely reducible to changes of spindle frequency. Conclusions As a main finding, our cross-sectional study shows that the first form of mature spindle (i.e., corresponding to the adult phasic event of NREM sleep) is marked by the emergence of slow spindles on anterior regions around the age of 12 months.

This review discusses the data of new researches on the functional purpose of sleep and its stages, and its role in the development of pathological conditions. The main modern hypotheses and concepts about a role of slow sleep and REM-sleep (rapid eye movement) are interpreted. The visceral theory of slow sleep as an activator of restorative processes in the brain and manager of internal organs functions is described. A brain "drainage" function of slow sleep is known. Recent studies suggest sleep-wake disturbances, for example, obstructive apnea syndrome, may influence Alzheimer's disease (AD) onset and progression. Possible mechanisms such asfunctional disorders of brain lymphatic system during slow sleep and the extracellular accumulation of the amyloid-s (As) peptide underlying the relationship between the sleep-wake disturbances and AD are described. The role of REM-sleep in the formation of the central nervous system in the early postnatal period and the performance of the function of mental adaptation are discussed. In this article, we presented data about the role both of neurotransmitters and neuropeptides in the regulation of sleep-wake cycle and the maintenance of wakefulness and REM-sleep. The possible new approach to the forecasting of cognitive and emotional-affective disorders in sleep disturbances is substantiated from the perspective of modern neuroscience and sleep neurophysiology still in childhood is justified.

The questions of the ontogeny of a child’s sleep, starting with the stage of fetation, are considered. Data on the formation of certain fetal conditions that are analogues of fast and slow sleep in the postnatal period are given. The most important neurobiological preconditions for the formation of the child’s behavioral states are discussed, beginning with the neonatal period and until adolescence. Information on the specifics of the formation of periods of sleep and waking in infants, born in the outcome of premature birth, is presented. Changes in the bioelectrical activity of the brain in various states of the child at different stages of ontogeny are considered. The rationale for the risk of forming certain variants of sleep disorders in children of different age groups is given. The Russian-language version of the standardized questionnaire Child’s Sleep Habits Questionnaire (CSHQ), designed to detect sleep disorders in preschool and school-age children on the basis of parents’ questionnaires, is developed.

Encephalopathy with continuous spike-waves during slow-wave sleep (CSWS) evolves over time, and three stages can be recognized: before the onset of CSWS, during CSWS, and after the CSWS period. Clinical seizures tend to remit spontaneously around puberty. This pattern is independent of the etiological lesion. The CSWS also disappears in all cases. Focal abnormalities instead, may persist for some time after the disappearance of CSWS. The disappearance of the clinical seizures and CSWS may be simultaneous or seizures may disappear before or after disappearance of the CSWS pattern on the EEG. Electroclinical parameters in the pre-CSWS period that have been proposed to predict a poor outcome are early-onset seizures, appearance of new seizures, and a significant increase in seizure frequency. From the electrical point of view, an increase in the frequency of the interictal EEG paroxysms while awake and during sleep and bilateral spike-and-wave paroxysms may also be predictive of a poor evolution in CSWS. When CSWS disappears, neurocognitive and behavioral status improve, but in most patients, residual moderate to severe neurocognitive impairments remain. In non-lesional epilepsy, cognitive recovery after cessation of the CSWS depends on the severity and duration of the initial regression. The duration of the CSWS seems to be the most important predictor of cognitive outcome. Early recognition and effective therapy to reduce the seizures and resolve the CSWS may be crucial to improve long-term prognosis. Cognitive recovery is observed in patients who respond well to AED treatment and outcome depends on the etiology.

Objective The aim of this study was to describe the electroclinical spectrum in children with electrical status epilepticus in sleep (ESES)/continuous spikes and waves during slow sleep (CSWS) syndrome according to the EEG patterns. Methods Clinical data of 44 patients with ESES/CSWS syndrome who were treated and followed at least two years were analyzed. Records of EEGs of patients were reevaluated to determine two aspects of the ESES pattern: (1) the spike–wave index (SWI) on the NREM sleep EEG (Group I: typical vs. atypical ESES pattern (33/11 patients)) and (2) the area of maximum amplitude of continuous epileptic activity (Group II: anterior vs. posterior ESES pattern (33/11 patients)). Results Symptomatic etiology was more defined in patients with the typical ESES pattern (40%) than the group with the atypical ESES pattern (9%) by a factor of four. All patients were receiving at least two antiepileptic drug (AED) treatments. Eighteen patients (41%) received AEDs plus ACTH therapy. Complete disappearance of the ESES pattern on the EEG was observed in 18 patients (41%), more than 50% reduction was observed in five patients (11%), less than 50% reduction was observed in eight patients (18%), and no response was observed in five patients (11%). No significant difference was found when comparing the groups in terms of reduction of seizures and the SWI. Seizure outcome at the two-year follow-up was similar between the group with ESES treated with AEDs plus ACTH and the group with ESES treated with AEDs without ACTH therapy. Significance This study demonstrated that the rate of the SWI (typical vs. atypical ESES) and the maximum amplitude of the ESES pattern (anterior vs. posterior) have no significant correlation with seizure control and reduction of the SWI on the EEG in children with ESES syndrome.

Individual circadian preference types and sleep EEG patterns related to spindle characteristics, have both been associated with similar cognitive and mental health phenotypes. However, no previous study has examined whether sleep spindles would differ by circadian preference. Here, we explore if spindle amplitude, density, duration or intensity differ by circadian preference and whether these associations are moderated by spindle location, frequency, and time distribution across the night. The participants (N = 170, 59% girls; mean age = 16.9, SD = 0.1 years) filled in the shortened 6-item Horne-Östberg Morningness-Eveningness Questionnaire. We performed an overnight sleep EEG at the homes of the participants. In linear mixed model analyses, we found statistically significant lower spindle amplitude and intensity in the morning as compared to intermediate (P 0.06 for spindle duration and density). Spindle frequency moderated the associations (P 0.2 for fast (>13 Hz)). Growth curve analyses revealed a distinct time distribution of spindles across the night by the circadian preference: both spindle amplitude and intensity decreased more towards morning in the morning preference group than in other groups. Our results indicate that circadian preference is not only affecting the sleep timing, but also associates with sleep microstructure regarding sleep spindle phenotypes.

Fil: Cardinali, Daniel P. Pontificia Universidad Católica Argentina. Facultad de Ciencias Médicas. Departamento de Docencia e Investigación; Argentina Fil: Cardinali, Daniel P. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Fisiología; Argentina Fil: Esquifino, Ana I. Universidad Complutense. Facultad de Medicina. Departamento de Bioquímica y Biología Molecular III; España Abstract: From a physiological perspective the sleep-wake cycle can be envisioned as a sequence of three physiological states, identified by a particular homeostatic patent: wakefulness, non-rapid eye movement (NREM) or slow sleep, and REM sleep. These three physiological states are defined by a particular neuroendocrine-immune profile that regulates the immune system response. This review discusses the physiological basis of such a control of the immune system at different sleep stages, as well as the manner in which humoral signals (cytokines) produced by immunocompetent cells modify the mechanisms of sleep.

Since the age of three years the patient suffered from early drug-resistant partial epilepsy with electric status during slow sleep, owing to a micropolygyric malformation of the right fronto-temporo-parietal lobes. The hemispherotomy (when five years of age) was followed by immediate and persistent disappearance of the seizures and withdrawal of the treatment. The transfer of right hemispheric functions to the left hemisphere occurred very early; the child’s development was examined in relation to the restoration of these functions and the age at surgery. The early surgical intervention and the plasticity of the brain – along with an intensive cognitive rehabilitation – seem to be important in determining the favorable global cognitive outcome. Visuo-spatial abilities and multi-modal integration of these functions with memory, attention and language have been the most critical domains and are recently in progress. The rapidity of processing complex tasks is particularly lacking. This seems to be the expression of the defective development of the Central Executive System.

We present a patient with cryptogenic focal epilepsy and another with Dravet syndrome, who experienced seizure aggravation and negative myoclonus, associated with continuous spikes and waves during slow sleep, induced by levetiracetam. For both patients levetiracetam was discontinued, and there was significant improvement of this particular electroclinical picture.

Sudden epileptic falls are frequently reported in continuous spike-waves during slow sleep (CSWS) syndrome. Inhibitory seizures are usually considered as the underlying mechanism. However, published polygraphic recordings are rare. We report the case of a 22 month-old boy suffering from a symptomatic CSWS syndrome associated with a perinatal stroke involving the right middle cerebral artery territory. He presented with psychomotor regression and daily multiple falls related to myoclonic-atonic seizures. Neurophysiological examination showed secondary generalized myoclonus systematically correlated with a bilateral spike spreading from the right central area. This confirms that positive myoclonus, in addition to negative myoclonus, may be responsible for epileptic falls in CSWS syndrome. [Published with video sequences].

Using magnetoencephalography (MEG), we evaluated epilepsy patients who displayed a widespread distribution of electroencephalography (EEG) spikes. The propagation of intra- and inter-hemispheric interictal spikes was measured using MEG in 9 cases. Five cases with continuous spikes and waves during slow sleep (CSWS) showed inter-hemispheric propagation that suggested secondary bilateral synchrony. Three of the four patients with localization-related epilepsy (LRE) showed intra-hemispheric, anterior–posterior or posterior–anterior propagation, with one patient with LRE exhibiting inter-hemispheric propagation. MEG was used to measure the propagation of interictal spikes from epilepsy patients who displayed a widespread distribution of spikes by EEG. MEG may thus be a useful tool for determining the true epileptic focus in these patients.

We developed an EEG- and audio-based sleep sensing and enhancing system, called iSleep (interactive Sleep enhancement apparatus). The system adopts a closed-loop approach which optimizes the audio recording selection based on user's sleep status detected through our online EEG computing algorithm. The iSleep prototype comprises two major parts: 1) a sleeping mask integrated with a single channel EEG electrode and amplifier, a pair of stereo earphones and a microcontroller with wireless circuit for control and data streaming; 2) a mobile app to receive EEG signals for online sleep monitoring and audio playback control. In this study we attempt to validate our hypothesis that appropriate audio stimulation in relation to brain state can induce faster onset of sleep and improve the quality of a nap. We conduct experiments on 28 healthy subjects, each undergoing two nap sessions - one with a quiet background and one with our audio-stimulation. We compare the time-to-sleep in both sessions between two groups of subjects, e.g., fast and slow sleep onset groups. The p-value obtained from Wilcoxon Signed Rank Test is 1.22e-04 for slow onset group, which demonstrates that iSleep can significantly reduce the time-to-sleep for people with difficulty in falling sleep.

Objective – To evaluate the efficacy of levetiracetam (LEV) in continuous spikes and waves during slow sleep (CSWS). Despite first description dates back to 1971, no agreement exists about CSWS treatment. The condition is rare and controlled clinical trials are very difficult to perform, so the reports about efficacy of different drugs are anecdotal. Patients and methods – We introduced LEV in three children affected by symptomatic focal epilepsy and pharmacoresistant CSWS and evaluated clinical, neuropsychological and electroencephalographic outcome. Results – Two cases responded completely, one case showed only a mild reduction of spikes and waves during slow sleep. Conclusion – Even if our report is anecdotal, LEV expands the spectrum of antiepileptic drugs that can be used for the treatment of CSWS. LEV efficacy should be confirmed in larger series.

Hormonal therapy or ketogenic diet often permits overcoming the challenging periods of many epileptic encephalopathies (West and Lennox-Gastaut syndromes and encephalopathy with continuous spike-waves in slow sleep), but relapse affects over 20% of patients. We report here a monocenter pilot series of 42 consecutive patients in whom we combined oral steroids with the ketogenic diet for corticosteroid-resistant or -dependent epileptic encephalopathy. We retrospectively evaluated the effect on seizure frequency, interictal spike activity, neuropsychological course, and steroid treatment course. Twenty-three patients had West syndrome (WS), 13 had encephalopathy with continuous spike-waves in slow sleep (CSWS), and six others had miscellaneous epileptic encephalopathies. All patients succeeded to reach 0.8 to 1.6g/l ketone bodies in the urine following the usual KD regimen. For at least 6 months, 14/42 responded to the addition of the ketogenic diet: 4/23 with WS, 8/13 with CSWS, and 2/6 with miscellaneous epileptic encephalopathies. The addition of the KD allowed withdrawing steroids in all responders. Among them, 10/15 had been patients with steroid-dependent epileptic encephalopathy and 4/27 patients with steroid-resistant epileptic encephalopathy. Therefore, the ketogenic diet can be used successfully in combination with corticosteroids for epileptic encephalopathies. Patients presenting with steroid-dependent CSWS seem to be the best candidates.

To investigate differences in sleep spindle properties and scalp topography between patients with rapid eye movement sleep behaviour disorder (RBD) and healthy controls, whole-night polysomnograms of 35 patients diagnosed with RBD and 35 healthy control subjects matched for age and sex were compared. Recordings included a 19-lead 10-20 electroencephalogram montage and standard electromyogram, electrooculogram, electrocardiogram and respiratory leads. Sleep spindles were automatically detected using a standard algorithm, and their characteristics (amplitude, duration, density, frequency and frequency slope) compared between groups. Topological analyses of group-discriminative features were conducted. Sleep spindles occurred at a significantly (e.g. t34 = -4.49; P = 0.00008 for C3) lower density (spindles ∙ min(-1) ) for RBD (mean ± SD: 1.61 ± 0.56 for C3) than for control (2.19 ± 0.61 for C3) participants. However, when distinguishing slow and fast spindles using thresholds individually adapted to the electroencephalogram spectrum of each participant, densities smaller (31-96%) for fast but larger (20-120%) for slow spindles were observed in RBD in all derivations. Maximal differences were in more posterior regions for slow spindles, but over the entire scalp for fast spindles. Results suggest that the density of sleep spindles is altered in patients with RBD and should therefore be investigated as a potential marker of future neurodegeneration in these patients.

Objective To determine the etiology of epilepsy with continuous spikes and waves during slow sleep (CSWS)/electrical status epilepticus during sleep (ESES) in an 8-year old boy with a history of neuroblastoma and opsoclonus-myoclonus. Material & methods A combination of clinical characterization and follow-up, video EEG and laboratory investigations. Results We report the case of an 8-year old boy with a history of neuroblastoma and opsoclonus-myoclonus, who presented with intellectual disability, pharmacotherapy-resistant epilepsy and CSWS/ESES. Although the patient's neuroblastoma had been successfully treated 8 years prior to presentation and an extensive workup did not show a tumor reoccurrence, testing for onconeuronal antibodies was positive for anti-Ma2 and anti-CV2/CRMP5 antibodies. High-dose intravenous methylprednisolone and a taper of oral methylprednisolone were given, leading to a significant clinical improvement. During the taper the patient's condition and EEG manifestations deteriorated again necessitating another cycle of steroid therapy, which lead to a stable improvement. During a 6-month follow-up no CSWS/ESES was seen on EEG and anti-Ma2 and anti-CV2/CRMP5 antibodies remained undetectable. Conclusion This case suggests that onconeuronal antibodies may be involved in the pathogenesis of CSWS/ESES.

The XYY syndrome is a sex chromosome aneuploidy occurring in one of 1,000 live male births. Only few data exist regarding the correlation between this syndrome and epilepsy. An EEG pattern suggestive of benign focal epilepsy with centro-temporal spikes has recently been described in four XYY patients. We report the first patient with XYY trisomy, rolandic spikes, and atypical evolution with continuous spikes and waves during slow sleep (CSWSS). The present report suggests that the association between an EEG pattern similar to that of BECTS and 47, XYY karyotype may not be coincidental. Moreover, we show that an atypical evolution with CSWSS may occur in this chromosomal disorder.

This paper presents the relations between the slow (< 1 Hz) oscillation (characterizing the activity of corticothalamic networks during quiescent sleep in cats and humans), sleep K-complexes, and some paroxysmal developments of sleep patterns. At the cellular level, the slow oscillation is built up by rhythmic membrane depolarizations and hyperpolarizations of cortical neurons. The EEG expression of this activity is marked by periodic K-complexes which reflect neuronal excitation. The slow oscillation triggers, groups and synchronizes other sleep rhythms, such as thalamically generated spindles as well as thalamically and cortically generated delta oscillations. We discuss the distinctness of the slow (< 1 Hz) and delta (1-4 Hz) oscillations. We also show that the slow cortical oscillation underlies the onset of spike-wave seizures during sleep by transforming the periodic K-complexes into recurrent paroxysmal spike-wave complexes.

Summary Background Epileptic syndromes with continuous spikes-waves during sleep (CSWS) represent a wide spectrum of epileptic disorders having CSWS as a common EEG-feature. Defined therapeutic strategies are still lacking. We evaluated the efficacy of lacosamide add-on therapy on the EEG, behavior, and cognition in children with CSWS. Material and methods Eight children with CSWS refractory to other conventional antiepileptic drugs were included in the study. A 24-h EEG recording was performed at 6-month-interval in all patients. The spike-wave index (SWI) was obtained in each 24-h EEG recording. Neuropsychological data were obtained before lacosamide introduction and after a minimum of 12 months of therapy. Results After a 6-month period of therapy, 75% of patients was defined as responder, 12.5% as partial responder and another 12.5% as non-responder. In particular, 24-h EEG normalized in 3 cases (37%). After a minimum of 12 months, 24-h EEG normalized in another patient while two patients showed electroclinical relapses. A total of 62.5% of patients was therefore defined as responder. Neuropsychological functions slightly improved in 25% of patients. Conclusion Although further studies are needed to validate our observations, this study suggests that lacosamide add-on therapy may be safe and effective in children affected by CSWS.

The child is cast into slow sleep phase (SSP) by exposure to monotonous action of the locomotor robot thus creating movement stereotypes during recurrent day sessions.

A long‐term follow‐up study was conducted in patients affected by Continuous Spikes and Waves during slow Sleep (CSWS) to evaluate the long-term outcomes. Twenty-five patients (19 males, 6 females), from 2 to 16 years of age (mean age 6 years ± 3 SD), affected by CSWS syndrome, as defined by the International League Against Epilepsy (ILAE, 1989), were enrolled and followed for 11 years (mean duration of follow‐up: 3.9 years). At the time of the appearance of CSWS, one or more neuropsychiatric disorders were present in 96% of the patients, such as behavioral problems in 54%, mental retardation in 37.5%, learning disabilities in 33%, developmental coordination disorder in 17%, language disorder in 12.5%, and pervasive developmental disorder in 8%. During the follow-up, neuropsychiatric dysfunctions remained unaltered in 52% of the patients, worsened in 24%, and improved in only 24%. Our data confirm that CSWS may be associated with a broad spectrum of neuropsychiatric disorders and may promote their worsening over time. Moreover, the findings cannot be generalized to all cases of children with CSWS because most of the children in the subgroups with no change in outcome and worse outcome had symptomatic CSWS.

Epilepsy with continuous spike-waves during slow sleep (CSWS),which is one of the hallmarks of electrical status epilepticus during slow wave sleep (ESES), is a functional disorder with the following features: severe paroxysmal EEG disturbance; seizures that may be severe but self-limited; behavioral deterioration, with or without premorbid developmental disturbances; no demonstrable brain pathology sufficient to explain the behavioral deterioration; and stabilization or improvement of behavior once the epileptiform EEG abnormalities resolve [1]. Much serious in CSWS are cognitive and behavioral disturbances. In CSWS, paroxysmal activity permanently affects the frontal lobes and higher cognitive functions. At highest risk for permanent sequelae are those with the earliest and longest exposure to the active phase of CSWS. When and how should CSWS be treated?

Cathodal transcranial direct current stimulation (tDCS) decreases cortical excitability. The purpose of the study was to investigate whether cathodal tDCS could interrupt the continuous epileptiform activity. Five patients with focal, refractory continuous spikes and waves during slow sleep were recruited. Cathodal tDCS and sham stimulation were applied to the epileptic focus, before sleep (1 mA; 20 min). Cathodal tDCS did not reduce the spike-index in any of the patients.

Purpose To evaluate the add-on effect of levetiracetam (LEV) treatment on the EEG and clinical status of children with continuous spikes-waves during slow sleep (CSWS). Methods 20 children with CSWS refractory to other conventional antiepileptic drugs (AEDs) received LEV 45–50mg/kg/day as add-on treatment, and were prospectively followed for a minimum period of 18 months. The patient population comprised seven cryptogenic, seven symptomatic and six idiopathic cases (atypical benign partial epilepsy, aBECTs). The electrographic evaluation included 24h EEG recordings taken every six months (minimum of three per child). Electrographically children were categorised as responders, partial responders or non-responders by comparing changes in the spike index (SI) during NREM-sleep with baseline SI before initiation of LEV. The clinical efficacy of LEV was assessed by comparing seizure frequency at the end of follow up with the baseline. The follow up duration varied from 18 to 53 months. Results Electrographic response was observed in 11 patients. Eight patients demonstrated a lasing response (more than 12 months): five from symptomatic, two – cryptogenic and one – idiopathic group respectively. Three children showed a partial response (6–12 months): one from symptomatic and two from idiopathic group. Eleven out of the 20 children were seizure free at baseline and during the whole follow up. The rest, six-symptomatic and three-cryptogenic patients, had seizures prior to LEV treatment initiation. Six became seizure free after add-on therapy with LEV, and in three children a significant reduction of seizure frequency was observed. Conclusion This study suggests that add-on therapy with LEV is more effective in children with CSWS resulting from a known underlying structural brain lesion (the symptomatic group).

Slow-wave sleep is characterized by spontaneous alternations of activity and silence in corticothalamic networks, but the causes of transition from silence to activity remain unknown. We investigated local mechanisms underlying initiation of activity, using simultaneous multisite field potential, multiunit recordings, and intracellular recordings from 2 to 4 nearby neurons in naturally sleeping or anesthetized cats. We demonstrate that activity may start in any neuron or recording location, with tens of milliseconds delay in other cells and sites. Typically, however, activity originated at deep locations, then involved some superficial cells, but appeared later in the middle of the cortex. Neuronal firing was also found to begin, after the onset of active states, at depths that correspond to cortical layer V. These results support the hypothesis that switch from silence to activity is mediated by spontaneous synaptic events, whereby any neuron may become active first. Due to probabilistic nature of activity onset, the large pyramidal cells from deep cortical layers, which are equipped with the most numerous synaptic inputs and large projection fields, are best suited for switching the whole network into active state.

Continuous spikes and waves during slow wave sleep (CSWS) is rare and is considered to be an age-related epileptic syndrome occurring only in children. We report the case of a 21-year-old patient diagnosed with this syndrome. The patient had a history of seizures since the age of 3 and was admitted for continuous video/EEG monitoring to evaluate seizure exacerbation and unprovoked outbursts of anger. During 3 days of monitoring, awake EEG recordings showed focal slow wave activity in the right temporal region. CSWS were observed. After a change in his antiepileptic drug regimen, subsequent EEG recordings showed resolution of CSWS. As shown in our patient, CSWS can be observed in adults. In addition, continuous video/EEG monitoring including sleep is important in the evaluation of patients with sudden deterioration of seizure control accompanied by behavioral changes.

The authors report the case of a child with cerebral palsy and refractory epilepsy who developed nonconvulsive status epilepticus without acute medical cause treated successfully with levetiracetam. In accordance with other studies whose authors hypothesized that aggressive treatment may worsen the prognosis in elderly patients with nonconvulsive status epilepticus, the present authors successfully used a more conservative approach to the treatment of nonconvulsive status epilepticus in their patient. This case suggests that levetiracetam is a useful option for the treatment of nonconvulsive status epilepticus in childhood, in accordance with some authors who have described the anticonvulsant effects of levetiracetam in experimental status epilepticus and in status epilepticus in adults and in children with continuous spike waves during slow sleep.

The present growing field of molecular imaging, including multimodality microimaging techniques and spectroscopic approaches, is mainly based on small animal studies. Monitoring such models requires an efficient treatment and use of electrophysiological signals which may be spoiled by environmental effects especially when working with nuclear magnetic resonance (NMR) since radiofrequency (RF) pulses and magnetic field gradient commutations may create spurious supplementary signals. In this work, a method is given for EEG and EMG denoising of signals acquired during phosphorous magnetic resonance (MR) brain spectroscopy data acquisition on a rat model developed for sleep/awake studies. The proposed approach is based on wavelet decomposition and the key method is to turn into profit the shape variations of EMG during the time course of sleep/awake cycles. Statistical properties of the noise are studied using EMG recorded during paradoxical sleep as noise model. A specific estimation of noise level using EMG recorded during slow sleep leads to an optimal wavelet coefficients thresholding. This approach is well suited to improve signal to noise ratio of EEG and EMG and to preserve small amplitude electro physiological signals.