Continuous Spikes And Waves During Sleep Research Articles

Evaluation of long-term neurocognitive functions in patients with epileptic encephalopathy with continuous spike-and-wave during sleep (CSWS)/epileptic encephalopathy with spike-and-wave activation in sleep (EE-SWAS)

ObjectivesEpileptic encephalopathy with continuous spike-and-wave during sleep (CSWS) or the newly named Epileptic encephalopathy with spike-and-wave activation in sleep (EE-SWAS) is a syndrome in which epileptiform abnormalities are associated with the progressive impairment of cognitive functions. This study aimed to evaluate the neurocognitive executive functions of patients at later ages and determine the long-term prognosis of the condition, as well as the factors affecting this. MethodsThis is a hospital-based cross-sectional study of 17 patients with a diagnosis of CSWS, and a minimum age of 7.5 years. The Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) was used for neurocognitive assessment. The use of immunotherapy (intravenous immunoglobulin and/or steroid for at least 6 months) at the time of initial diagnosis, baseline activity and spike wave index (SWI) of the last wake and sleep EEG, cranial MRI findings, active epileptic seizures since the last examination, and WISC-IV parameters were statistically compared. The results of patients with genetic etiology determined by the whole exome sequencing (WES) method are also reported. ResultsA total of 17 patients were included in the study, with a mean age of 10.30 ± 3.15 years (range from 7.9 to 15.8 years). The mean full scale IQ score of the subjects was 61.41 ± 17.81 (range 39–91), classified as follows: 5.9% (n = 1), average; 23.5% (n = 4), low average; 5.9% (n = 1), very low; 35.3% (n = 6), extremely low (upper range); 29.4% (n = 5), extremely low (lower range) intelligence. Among the four domains of WISC-IV, the most affected index was the Working Memory Index (WMI). EEG parameters, cranial MRI findings and treatment with immunotherapy did not have a significant effect on neurocognitive outcomes. Thirteen patients (76%) were evaluated with WES for a genetic etiology. Pathogenic variants in 5 different genes (GRIN2A, SLC12A5, SCN1A, SCN8A, ADGRV1) associated with epilepsy were detected in 5/13 patients (38%). ConclusionThese results indicated that neurocognition is highly affected in the long term in CSWS.

Continuous Spikes and Waves During Sleep (CSWS), Severe Epileptic Encephalopathy, and Choreoathetosis due to Mutations in FRRS1L.

Background. Biallelic pathogenic variants in the FRRS1L gene are now known to cause developmental and epileptic encephalopathy-37 (DEE37). It can also be associated with chorea and continuous spikes and waves during sleep (CSWS). CSWS is a rare age-related epileptic encephalopathy syndrome of childhood that is characterized by seizures, neurocognitive regression and electrical status epilepticus during sleep (ESES) on electroencephalogram (EEG) that evolves in four stages. Seizures start during the prodromal phase but the ESES on EEG appears only during acute stage and this is the stage when the diagnosis of CSWS can be made. Methods. We present two patients with FRRS1L mutation causing DEE37 with CSWS. We also review twenty-nine cases of DEE37 described in the literature before and discuss its association with CSWS in the total cohort of thirty-one cases. Results. Developmental regression was found in 80% of the patients, mean age of seizure onset was 18 months, ESES or slow spike and wave on the EEG were reported mostly in the older patients (median age of 11 years) and hypsarrhythmia was reported in younger patients (median age of 4 years). This could suggest that if the younger patients were followed longer their EEG would have evolved into ESES during the acute stage of this syndrome and a diagnosis of CSWS could be made. Conclusion. Recognizing ESES and the natural evolution of CSWS is important in diagnosis and proper management of these patients. More detailed report of EEG findings and the evolution of epilepsy and development are needed to further characterize this syndrome.

Neuropsychological Assessment of a Continuous Spikes and Waves During Sleep (CSWS) Patient: a Case Study/Description in Childhood

Neuropsychological Assessment of a Continuous Spikes and Waves During Sleep (CSWS) Patient: a Case Study/Description in Childhood

Epileptic Encephalopathies in Infants and Children: Study of Clinico-Electroencephalographic Spectrum in a Tertiary Hospital in Bangladesh

Background: The epileptic encephalopathies collectively exact an immense personal, medical, and financial toll on the affected children, their families, and the healthcare system. Objective: This study was aimed to delineate the clinical spectrum of patients with Epileptic encephalopathies (EEs) and classify them under various epileptic syndromes. Methods: This was a cross-sectional study that was carried out in the department of Neurophysiology of the National Institute of Neurosciences and Hospital, Bangladesh from July 2016 to June 2019. Children with recurrent seizures which were difficult to control and associated with developmental arrest or regression in absence of a progressive brain pathology were considered to be suffering from EE. Children under 12 years of age fulfilling the inclusion criteria were enrolled in the study. These patients were evaluated clinically and Electroencephalography (EEG) was done in all children at presentation. Based on the clinical profile and EEG findings the patients were categorized under various epileptic syndromes according to International League Against Epilepsy (ILAE) classification 2010. Results: A total of 1256 children under 12 years of age were referred to the Neurophysiology Department. Among them, 162 (12.90%) fulfilled the inclusion criteria. Most of the patients were male (64.2%) and below 1 year (37.7%) of age. The majority (56.8%) were delivered at the hospital and 40.1% had a history of perinatal asphyxia. Development was age-appropriate before the onset of a seizure in 38.9% of cases. Most (53.7%) of the patients had seizure onset within 3 months of age. Categorization of Epileptic syndromes found that majority had West Syndrome (WS) (37.65%) followed by Lennox-Gastaut syndrome (LGS) (22.22%), Otahara syndrome (11.73%), Continuous spike-and-wave during sleep (CSWS) (5.66%), Myoclonic astatic epilepsy (MAE) (4.94%), Early myoclonic encephalopathy (EME) (3.7%), Dravet syndrome (3.7%) and Landau-Kleffner syndrome (LKS) (1.23%). 9.26% of syndromes were unclassified. Conclusion: EEG was found to be a useful tool in the evaluation of Epileptic encephalopathies. The clinico-electroencephalographic features are age-related. Their recognition and appropriate management are critical.

A qualitative awake EEG score for the diagnosis of continuous spike and waves during sleep (CSWS) syndrome in self-limited focal epilepsy (SFE): A case-control study

PurposeTo determine whether awake EEG criteria can differentiate epileptic encephalopathy with continuous spike and waves during sleep (EE-CSWS) at the time of cognitive regression from typical, self-limited focal epilepsy (SFE). MethodsThis retrospective case-control study was based on the analysis of awake EEGs and included 15 patients with EE-CSWS and 15 age-matched and sex-matched patients with typical SFE. The EEGs were anonymised and scored by four independent readers. The following qualitative and quantitative EEG indices were analysed: slow-wave index (SLWI), spike-wave index (SWI), spike-wave frequency (SWF), long spike-wave clusters (CLSW) and EEG score (between grades 0 and 4). Sensitivity and specificity were assessed using receiver operating characteristic (ROC) curves and their reproducibility with a kappa test. ResultsBased on a highly sensitive cut-off, EE-CSWS patients were 8.4 times more likely than those with SFE to have an SLWI > 6%, 15 times more likely to have an SWI > 10 % and six times more likely to have a CLSW of ≥ 1 s. There was substantial agreement between readers (with kappa values of 0.64, 0.69 and 0.67). EE-CSWS patients were 13 times more likely to have an SWF of > 11 % and 149 times more likely to have an EEG score of ≥ 3 than typical SFE patients. Agreement about these ratings was almost perfect (kappa 0.91 and 0.86). ConclusionAn EEG score of ≥ 3 on a 20-min awake EEG differentiates typical SFE from EE-CSWS at the time of cognitive regression, with good reliability across readers with different levels of expertise.

Clinical Forms and GRIN2A Genotype of Severe End of Epileptic-Aphasia Spectrum Disorder.

Objective: This study aims to analyze the electroclinical characteristics and gene test results of children on the severe end of the epilepsy aphasia spectrum (EAS) and also the correlation of EAS-related GRIN2A genes to explore the genotype-phenotype relationships, as well as potential pathogenic mechanism of EAS.Methods: A retrospective study was conducted on the participants diagnosed with Landau-Kleffner syndrome (LKS), epileptic encephalopathy with continuous spike-and-wave during sleep (CSWS), and atypical benign partial epilepsy (ABPE) at the Children's Hospital of Chongqing Medical University from January 2013 to June 2019. Whole-exome sequencing was performed in six patients, and epileptic panel was carried out in two. In addition, we reviewed all the published literatures reporting EAS patients with pathogenic variants until June 2019 and conducted Gene Ontology (GO) analysis, as well as protein-protein interaction (PPI) network.Results: The mean age at seizure onset was 55.4 ± 27.0 months. The baseline severity of the spike-wave index (SWI) was not significantly correlated with intellectual disability (ID) level. Two pathogenic de novo GRIN2A null variants were identified in patients with ABPE who had less severe ID, despite the electrical status epilepticus during slow-wave sleep (ESES). By literature reviewing, 18 GRIN2A missense mutations and 11 GRIN2A truncating mutations which lead to N-methyl-d-aspartate receptors' loss of function has been reported. Of these mutations, 9 (31.0%) are situated in amino (N)-terminal domain, 6 (20.7%) in linger-binding domain S1, and 10 (34.5%) in linger-binding domain S2. EAS-related genes were enriched in the biological process of chemical synaptic transmission and vocalization (FDR, <0.01). The hub protein in PPI network is GluN2A, which might affect language function via foxp2-srpx2/uPAR signal network.Conclusion: Our data suggested that when children suspected with benign epilepsy of children with centrotemporal spikes (BECTs) have early-onset age, changed seizure semiology, and deterioration of behavior/cognition/motor function, neurologists should be alert of the appearance of ESES. The neuropsychological deterioration in children with EAS might not only be completely affected by electric discharge severity but also genetic etiology. Our finding also enforced the current genotype-phenotype relationship theory about EAS. For EAS children, GRIN2A-FOXP2-SRPX2/uPAR signal network might contribute to the mechanism of their language deficit.

Clinical spectrum and treatment outcome of 95 children with continuous spikes and waves during sleep (CSWS).

Continuous spikes and waves during sleep (CSWS) is an epileptic encephalopathy characterized by generalised epileptiform activity and neurocognitive dysfunction. Causes and outcome are diverse and treatment is mainly empirical. Retrospective descriptive analysis of clinical and EEG data of children with CSWS diagnosed between 1998 and 2018at the University Hospital Heidelberg. Ninety-five children were included with a median age at diagnosis of 5.4 years. A structural/metabolic aetiology was found in 43.2%, genetic alterations in 17.9%, while it remained unknown in 38.9%. The proportion of patients with genetic aetiology increased from 10.3% (1998-2007) to 22.8% (2008-2018). On average, each patient received 5 different treatments. CSWS was refractory in >70% of cases, steroids and neurosurgery were most effective. No difference was observed between children with CSWS or Near-CSWS (Spike-Wave-Index 40-85%). Our cohort confirms CSWS as an age-dependent epileptic encephalopathy. Structural brain abnormalities were most frequent, but genetic causes are increasingly identified. More specific criteria for the diagnosis and treatment goals should be elaborated and implemented based on evidence. This study is the largest monocentric observational study on treatment effects in children with CSWS, providing data for diagnostic and therapeutic decisions.

Predictors of one-year language and seizure outcomes in children with epileptic encephalopathy with continuous spike-and-wave during sleep (CSWS)

PurposeEpileptic encephalopathy with continuous spike-and-wave during sleep (CSWS), with its associated impact on language, is an important cause of morbidity with epilepsy in children. The effects of various treatment-approaches and the aetiological/electrophysiological factors affecting therapeutic response are not fully understood. MethodA retrospective study of patients admitted to the institute and diagnosed to have CSWS pattern on EEG was conducted. Spike and Wave Frequency/100 s(SWF) was calculated from sleep-EEG records. Language development and seizure outcomes were assessed at baseline and 1 year. ResultsFifty-two children were included (idiopathic CSWS, N = 19; symptomatic CSWS N = 33).The 2 groups differed in terms of younger age at seizure onset in symptomatic CSWS (p = 0.006), early age at language regression (p = 0.046), history of neonatal seizures (p = 0.038) and slowing of background activity on EEG (p = 0.024). Language regression was noted in 63.5 % of the cohort. Twenty-five (48%) patients received steroids with improvement in seizures (p < 0.001). Twenty-one (40.3 %) received steroids and intravenous immunoglobulin (IVIG) with improvement in seizure score (p = 0.002) at 1 year. Both immune-modulation arms irrespective of etiological subgroups had comparable proportions of children with expressive and receptive language gains. On 1 year follow-up, seizure remission was noted in 13(25 %) patients, with improved seizure score in 32/39 (61.5 %) patients and language improvement in 32 children (60.8 %). Patients with normal background on baseline EEG, generalised spikes, absent frontal-negative spikes and SWF < 170 were found to have improved language estimates on follow-up. ConclusionsDespite clinical and therapeutic outcome differences between idiopathic and symptomatic CSWS, immune-modulation appears effective irrespective of aetiology. Analysis of EEG variables enables prediction of language outcomes at 1 year follow-up.

High-frequency oscillations in a spectrum of pediatric epilepsies characterized by sleep-activated spikes in scalp EEG

ObjectiveWe studied ripple-band (80–200 Hz) high-frequency oscillations in scalp electroencephalogram (EEG) in various pediatric epilepsies featuring sleep-activated spikes, such as epileptic encephalopathy with continuous spike-and-wave during sleep (CSWS) and investigated their characteristics. MethodsThe subjects were 94 children with epileptic disorders including idiopathic and non-idiopathic CSWS, benign epilepsy with centrotemporal spikes (BECTS), Panayiotopoulos syndrome, other types of focal epilepsies (oFE), and focal spikes without clinical seizures (Latent). We detected ripple oscillations using a semi-automatic detection tool based on localized power increase. ResultsIn the idiopathic CSWS Group, the median ratio of ripples per spike in the initial EEG was 5.73, which was significantly higher than those in the BECTS, Panayiotopoulos syndrome, oFE, and Latent Groups (0.39, 0.02, 0.35, 0, respectively, all with p < 0.01). Ripples were particularly frequent at younger ages. ConclusionsThis paper is the first to confirm a high ratio of ripples per spike in CSWS in the largest number of patients to date. SignificanceThe dense generation of ripples, which occurs through a combination of heavy loading of individual spikes with ripples and large numbers of spikes during sleep, characterizes CSWS and might be closely related to the pathophysiology of this epileptic encephalopathy.

Scalp EEG high frequency oscillations as a biomarker of treatment response in epileptic encephalopathy with continuous spike-and-wave during sleep (CSWS)

PurposeWe investigated whether the presence of interictal scalp EEG high frequency oscillations (HFOs) in children with epileptic encephalopathy with continuous spike-and-wave during sleep (CSWS) can predict seizure and cognitive outcome after steroid therapy. MethodsTwenty-two children with CSWS were prospectively enrolled and received methylprednisolone therapy. Interictal scalp HFOs, spike wave index (SWI) and intelligence quotient (IQ) were assessed before and after the treatment. The children were divided into two groups based on the early seizure reduction ratio at 2 weeks (≥50%, “response group”; otherwise “non-response group”). The “response group” was further divided into two subgroups (“relapse” and “non-relapse” subgroups) according to the late seizure outcome (after 3 months). ResultsInterictal HFOs and electrical status epilepticus in sleep (ESES) (defined as SWI ≥ 85%) were detected in all children at the baseline. In the response with relapse group (n = 11), the detection ratio of HFOs was significantly higher than that of ESES at 2 weeks (81.2 vs. 27.3%), 3 months (90.9 vs. 36.4%), and 6 months (100 vs. 54.5%) post-therapy. In the non-response group (n = 4), both HFOs and ESES persisted in all children. The average IQ improved significantly only in the response with non-relapse group. The persistence of HFOs negatively correlated with both the average IQ, yet the persistence of ESES did not. ConclusionInterictal scalp HFOs may be a favorable non-invasive biomarker of predicting seizure and cognitive outcome in CSWS.

A new cause of developmental and epileptic encephalopathy with continuous spike-and-wave during sleep: CDKL5 disorder

ABSTRACTThe CDKL5 disorder is characterized by early onset epilepsy, stereotypical hand movement, absent speech and severe hypotonia. Herein, we report epileptic encephalopathy with continuous spike-and-wave during sleep (CSWS) in apatient with CDKL5 disorder. She admitted with complaints of frequently recurring generalized tonic and myoclonic seizures. The diagnoses were confirmed by de novo CDKL5 mutation, c.197_198delCT (p.L67QfsX23). Interictal EEG revealed generalized spike and slow-wave activity, occurring intermittently in wakefulness but present for at least 85% of non-REM sleep, consistent with the diagnosis of CSWS. To our knowledge, this is the first report of CSWS associated with CDKL5 disorder.

Epileptiform activity index for the evaluation of treatment efficacy in patients with epileptic encephalopathy

Continuous spike and waves during sleep (CSWS) may lead to different cognitive, motor and behavioral symptoms. CSWS is characterized by an electroencephalography (EEG) pattern of electrical status epilepticus during sleep (ESES). The article reviews the main criteria of ESES, localization of EEG-changes and main EEG-patterns. An analysis of abnormal neuroimaging findings in patients with ESES was performed. The main pathophysiologic theories of ESES pattern formation are reviewed. ESES diagnosis is usually based on rough visual assessment of the number of spikes and waves, but other methods of assessment are also utilized, including spike-wave index (SWI), which is widely used in clinical practice. SWI reflects the percentage of sleep covered with spikes and waves. Two different strategies of SWI calculation are used, but none of them is officially validated. Moreover, there is no consensus on the period of sleep to be used for the calculation of SWI. The article presents a detailed review of calculation and utilization of SWI. It is concluded that further research is needed to develop an optimal algorithm of SWI calculation.

Study of GRIN2A mutation in epilepsy-aphasia spectrum disorders

To detect potential mutations of the glutamate receptor subunit (GRIN2A) gene and delineate the clinical-genetic characteristics of patients with epilepsy-aphasia spectrum (EAS) disorders. One hundred twenty two patients with Landau-Kleffner syndrome (LKS), epileptic encephalopathy with continuous spike-and-wave during sleep (CSWS), benign childhood epilepsy with centrotemporal spikes (BECT) and BECT variants were recruited. Potential mutations of the GRIN2A gene were screened with Sanger sequencing. And clinical-genetic characteristics for all patients were analyzed. The patients have included 9 LKS, 26 CSWS, 42 BECT variants and 45 BECT. The mean age of onset of seizure or aphasia was 5 years old (10 months to 11 years). Mutation screening has detected 4 possible pathogenic missense mutations including c.2278G>A (p.G760S), c.4153G>T (p.D1385Y), c.1364G>A (p.C455Y) and c.691T>C (p.C231R) in four unrelated probands, which comprised one case with LKS and three with BECT variants. The mutation rate was 11.1% (1/9) for LKS and 7.2% (3/42) for BECT variants. No GRIN2A mutation was found in the 26 patients with CSWS and 45 patients with BECT. Among the 122 probands, 25 (20.5%) patients without a GRIN2A mutation had a positive family history of febrile seizures or epilepsy. GRIN2A mutation do exist in EAS patients, but with a relatively low rate. A proportion of EAS patients without a GRIN2A mutation have a positive family history, which suggested a complex mechanism for EAS.

Scalp-recorded high-frequency oscillations in childhood epileptic encephalopathy with continuous spike-and-wave during sleep with different etiologies

ObjectiveTo investigate high-frequency oscillations (HFOs) in epileptic encephalopathy with continuous spike-and-wave during sleep (CSWS) with different etiologies. MethodsTwenty-one CSWS patients treated with methylprednisolone were divided into structural group and genetic/unknown group. Comparisons were made between the two etiological groups: selected clinical variables including gender, age parameters, seizure frequencies and antiepileptic drugs; distribution of HFOs in pre-methylprednisolone electroencephalography (EEG) and percentage changes of HFOs and spikes after methylprednisolone treatment. ResultsThere were 7 patients (33%) in structural group and 14 patients (68%) in genetic/unknown group. No significant difference was found between the two groups regarding selected clinical variables. HFOs were found in 12 patients in pre-methylprednisolone EEG. The distribution of HFOs was focal and accordant with lesions in 5 of structural group, and it was also focal but in different brain regions in 7 of genetic/unknown group. The percentage reduction of total HFOs and spikes was 81% (158/195) and 19% (1956/10,037) in structural group, while 98% (315/323) and 55% (6658/12,258) in genetic/unknown group after methylprednisolone treatment. ConclusionThe etiologies had no distinct correlation with some clinical characteristics in CSWS. HFOs recorded on scalp EEG might not only be used as makers of seizure-onset zone (SOZ), but also have association with functional disruption of brain networks. Both HFOs and spikes reduced more in genetic/unknown patients than that in structural patients after methylprednisolone treatment and HFOs were more sensitive to treatment than spikes.

Speech and language neurodevelopmental disorders in epilepsy: pathophysiologic mechanisms and therapeutic approaches

Speech and language development may be impaired in all forms of epilepsy involving specialized functional areas in the dominant cerebral hemisphere and their connections. The concept of epilepsy-aphasia clinical spectrum was recently proposed, but the notion of aphasia is quite conditional here as many of these patients demonstrate disorders of speech and language development from their infancy. Those forms of epilepsy are considered as continuum from the most severe Landau-Kleffner syndrome (LKS) and epilepsy with continuous spike-and-wave during sleep (CSWS) (also indicating as electrical status epilepticus during sleep - ESES) to intermediate epilepsy-aphasia disorders (with incomplete correspondence to diagnostic criteria of LKS and epilepsy with CSWS). The mild end of the spectrum is represented by benign childhood epilepsy with centrotemporal spikes (rolandic), which is often associated with speech and language disorders. The importance of genetic factors is discussed, including mutations in SRPX2, GRIN2A and other genes. The perspectives of individualized pharmacotherapy in epilepsy, co-morbid with neurodevelopmental disorders or impairments of speech and language development, are depending on the progress in genetic studies. In the new generation of antiepileptic drugs the positive influence on neuroplasticity mechanisms and higher cerebral functions are supposed for levetiracetam.

Age-Dependency of Location of Epileptic Foci in "Continuous Spike-and-Waves during Sleep": A Parallel to the Posterior-Anterior Trajectory of Slow Wave Activity.

Epileptic encephalopathy with continuous spike-and-waves during sleep (CSWS) occurs during childhood and is characterized by an activation of spike wave complexes during slow wave sleep. The location of epileptic foci is variable, as is etiology. A relationship between the epileptic focus and age has been shown in various focal epilepsies following a posterior-anterior trajectory, and a link to brain maturation has been proposed. We hypothesize that in CSWS, maximal spike wave activity, corresponding to the epileptic focus, is related to age and shows a posterior-anterior evolution. In a retrospective cross-sectional study on CSWS (22 EEGs of 22 patients aged 3.1–13.5 years), the location of the epileptic focus is related to age and follows a posterior-anterior course. Younger patients are more likely to have posterior foci than older ones. We propose that the posterior-anterior trajectory of maximal spike waves in CSWS might reflect maturational changes of maximal expression of sleep slow waves, which follow a comparable course. Epileptic spike waves, that is, “hyper-synchronized slow waves” may occur at the place where the highest and therefore most synchronized slow waves meet brain tissue with an increased susceptibility to synchronization.

Hemispherotomy in children with electrical status epilepticus of sleep

OBJECTIVE Electrical status epilepticus of sleep (ESES) is a rare electrographic pattern associated with global regression, which is often poorly responsive to traditional epilepsy treatments and can have a devastating and permanent neurocognitive outcome. The authors analyzed clinical, electroencephalographic, and neuropsychological outcomes in 9 patients with refractory ESES treated with functional hemispherotomy to illustrate the wide clinical spectrum associated with the disease and explore the role of hemispherotomy in its treatment. METHODS During the period between 2003 and 2015, 80 patients underwent hemispherotomy at the authors' institution. Video electroencephalography (EEG) reports were reviewed for ESES or continuous spikes and waves during sleep (CSWS). Patients with preoperative ESES (> 85% slow-wave sleep occupied by spike waves), a unilateral structural lesion amenable to surgery, and more than 6 months of follow-up data were included in the analysis. Clinical data, EEG recordings, neuropsychological testing, and parental and clinician reports were retrospectively reviewed. RESULTS Nine patients were eligible for study inclusion. Age at seizure onset ranged from birth to 4.2 years (mean 1.9 years), age at ESES diagnosis ranged from 3.5 to 8.8 years (mean 6.0 years), and age at hemispherotomy ranged from 3.7 to 11.5 years (mean 6.8 years). All patients had drug-resistant epilepsy. The duration of epilepsy prior to hemispherotomy ranged from 2.7 to 8.9 years (mean ± SD, 5.0 ± 2.2 years). Engel Class I seizure outcome was observed in all 9 children, with a mean follow-up of 3.0 years (range 0.5-6.1 years). Hemispherotomy terminated ESES in 6 of 6 patients with available postoperative sleep EEG. All children had preoperative neuropsychological impairments. Developmental regression was halted postoperatively, but none of the children returned to their original pre-ESES baseline. Four children demonstrated academic gains, 2 of whom transitioned to mainstream classes. CONCLUSIONS Children with drug-resistant ESES and a unilateral structural lesion should be evaluated for hemispherotomy as they may experience the cessation of seizures, termination of ESES, and improvement in neuropsychological status.

EPILEPSY SYNDROMES WITH CONTINIUOS SPIKE AND WAVE ACTIVITY DURING SLEEP

Syndromes with continuous spikes and waves during sleep (CSWS) are being actively studied now. Etiological factors include both genetic causes and structural brain disorders; frequently – the damage of the thalamus, and congenital malformations. In most cases, the persistence of CSWS pattern leads to a neurocognitive dysfunction. Two mechanisms of the intellectual regression are supposed: a violation of brain maturation processes and the effect of the remote inhibition. The most effective treatment is considered to be a combination of hormones and antiepileptic drugs. It is often possible to restore a normal level of child development in case of the early diagnosis and rational therapeutic tactics. However, if more than 18 months has passed since the onset of seizures, as a rule, intellectual functions can’t be improved.

A prospective study of dexamethasone therapy in refractory epileptic encephalopathy with continuous spike-and-wave during sleep.

Epileptic encephalopathy with continuous spike-and-wave during sleep (CSWS) is an intractable form of epilepsy that has no consensus protocol for corticosteroid therapy. This prospective study aimed to evaluate the efficacy and tolerability of dexamethasone for the treatment of CSWS. Patients (age: 4 years to 12 years and 5 months) with CSWS that failed to respond to several antiepileptic drugs and prednisolone at our pediatric neurology outpatient clinic between 2007 and 2015 were treated with dexamethasone and prospectively analyzed. An initial 4-week dexamethasone (0.15 mg/kg/day p.o.) scheme was employed, and response was assessed. If effective, dexamethasone was maintained for 2-3 months and then slowly weaned over several months, depending on individual patient response at each follow-up. Systemic evaluations (clinical evaluations, electroencephalography recordings, and analysis of side effects) were performed regularly thereafter. Among 15 patients, 7 were defined as initial responders after 4-week dexamethasone treatment based on comprehensive clinical and electroencephalogram evaluations. The duration of dexamethasone treatment (including weaning) in these 7 patients was 6 to 10 months, and the follow-up duration was 6 months to 7 years. Three patients had no relapse after dexamethasone withdrawal at last follow-up. Among the other 4 patients, relapse was observed during dexamethasone withdrawal (n=1) or at 2-6 months after discontinuation of dexamethasone therapy (n=3). There were no serious or life-threatening side effects, and all observed side effects were reversible after discontinuation of dexamethasone. Continuous oral dexamethasone treatment is an effective and tolerable therapy and should be an option for the treatment of CSWS.

Treatment for continuous spikes and waves during sleep (CSWS): survey on treatment choices in North America.

Current literature does not allow an evidence-based approach to the treatment of continuous spikes and waves during sleep (CSWS). The aim of this study was to describe treatment choices made by clinicians caring for patients with CSWS in North America. A 24-question survey on treatment choices for CSWS was distributed to the members of the American Epilepsy Society (AES). The survey presented a clinical vignette of CSWS. The questions addressed treatment choices for that clinical scenario. Surveys were self-administered and collected using an online survey website (www.surveymonkey.com). Two-hundred thirty-two surveys were completed. Prominent sleep-potentiated spiking was considered to warrant treatment by 81% of respondents. The proportion of patients in whom cognitive improvement occurs when sleep-potentiated spiking is effectively treated is in >75% of patients (according to 16% of respondents), in 25-75% of patients (according to 52% of respondents), in <25% of patients (according to 20% of respondents), and no or unclear cognitive changes (according to 12% of respondents). The preferred first choice to reduce sleep-potentiated epileptiform activity was high-dose benzodiazepines (47%), valproate (26%), and corticosteroids (15%). The preferred second-choice was valproate (26%), high-dose benzodiazepines (24%), and corticosteroids (23%). Among high-dose benzodiazepines, the preferred one was diazepam 1 mg/kg for one night followed by 0.5 mg/kg/day. The preferred dose of valproate was 30-49 mg/kg/day. Among corticosteroids the preferred choice was oral prednisone 2 mg/kg/day. The most commonly considered endpoints of treatment efficacy were (in decreasing order): response of epileptiform activity in electroencephalography (EEG), cognitive function, and seizure reduction. Results were consistent among respondents with different levels of training and clinical experience. There were differences in conceptualization and treatment approaches between pediatric and adult neurologists. Most clinicians considered that prominent sleep-potentiated epileptiform activity should be treated. There was no agreement on best treatment, but potential candidates included high-dose benzodiazepines, valproate, levetiracetam, and corticosteroids.