Epidemiology of epilepsy in childhood: a cohort of 440 consecutive patients

The Prevalence and Risk Factors of Electrical Status Epilepticus During Slow-Wave Sleep in Self-Limited Epilepsy With Centrotemporal Spikes

Objective. To investigate the prevalence and risk factors for electrical status epilepticus during slow-wave sleep (ESES) in patients with self-limited epilepsy with centrotemporal spikes (SeLECTS). Methods. The clinical and follow-up data of children with SeLECTS were collected between 2017 and 2021. Patients were divided into typical ESES, atypical ESES, and non-ESES groups according to spike-wave indices (SWI). Clinical and electroencephalography characteristics were retrospectively analyzed. Logistic regression was used to identify risk factors for ESES. Results. A total of 95 patients with SeLECTS were enrolled. Seven patients (7.4%) developed typical ESES, 30 (31.6%) developed atypical ESES, 25 (26.3%) developed ESES at the first visit, and 12 (12.6%) developed ESES during treatment and follow-up. Multivariate logistic regression analysis showed that the risk factors for SeLECTS combined with ESES were Rolandic double or multiple spikes (OR = 8.626, 95% CI: 2.644-28.147, P < .001) and Rolandic slow waves (OR = 53.550, 95% CI: 6.339-452.368, P < .001). There were no significant differences in seizure characteristics, electroencephalogram (EEG) findings, or cognitive impairment between the atypical and typical ESES groups. Conclusion. More than one-third of the SeLECTS patients combined with ESES. Both atypical and typical ESES scores can affect cognitive function. On electroencephalography, interictal Rolandic double/multiple spikes and slow-wave abnormalities may indicate SeLECTS with ESES.

Unmet needs in epileptic encephalopathy with spike-and-wave activation in sleep: A systematic review

INTRODUCTION

Developmental and/or epileptic encephalopathy with spike-and-wave activation in sleep (D/EE-SWAS), also referred to as electrical status epilepticus during sleep (ESES) or epileptic encephalopathy with continuous spike-and-wave during sleep (CSWS or EE-CSWS), is a spectrum of rare childhood epileptic encephalopathies that can lead to long-term cognitive impairment. Despite the importance of early diagnosis and intervention for D/EE-SWAS, there is a paucity of well-controlled clinical trial data to inform treatment, and no approved treatments are available. To assess correlations between diagnosis, treatment, and outcomes in D/EE-SWAS, we carried out a systematic review of the literature.

METHODS

In August 2020, we conducted comprehensive database searches using search terms including "electrical status epilepticus," "ESES," "CSWS," and "Landau-Kleffner syndrome." Two or more independent reviewers screened titles, abstracts, and full-text articles for those that met the following criteria: prospective studies (randomized controlled trials [RCTs] or open-label trials), retrospective studies (drug evaluations or observational studies/chart reviews), and case series with ≥ 10 participants. Both interventional and non-interventional studies were included (i.e., drug intervention was not an inclusion criterion). Articles published before 2012, review articles, animal studies, and studies of surgical or dietary interventions were excluded. Standardized data extraction templates were used to capture data on study design, patient characteristics, interventions, and outcomes from each of the selected publications. Study quality was assessed using the Cochrane Risk of Bias Tool for RCTs and the Newcastle-Ottawa Scale (NOS) or the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for retrospective, observational studies.

RESULTS

A total of 34 studies were included for full data extraction, most of which were uncontrolled and observational. Interpretation of study outcomes was limited by small study populations, variability in inclusion criteria, and inconsistency in methods of assessment and reporting of outcomes, which resulted in large heterogeneity in patients and their presenting symptoms. Despite these limitations, some patterns could be discerned. Several studies found that longer duration of ESES and younger age at onset were correlated with more severe language and cognitive deficits. In addition, several studies reported an association between improvement in cognitive outcomes and reduction in electroencephalogram (EEG) abnormalities and/or seizure frequency. In the 16 prospective or retrospective studies that evaluated drug treatments (e.g., antiseizure medications, corticosteroids, and high-dose diazepam), there was some improvement in EEG, seizure, and/or cognitive outcomes, although the specific outcomes and rates of improvement reported varied from study to study.

CONCLUSION

Long-term cognitive deficits remain common in D/EE-SWAS, and data gaps exist in the literature that preclude an evidence-based approach to managing this complex epilepsy indication. Early intervention with more effective medications is needed to optimize long-term outcomes. Sufficiently powered, randomized, double-blind, controlled trials with standardized methods and predefined primary and secondary outcomes are needed.

Preliminary evidence of a relationship between sleep spindles and treatment response in epileptic encephalopathy

OBJECTIVE

Epileptic encephalopathy with spike-wave activation in sleep (EE-SWAS) is a challenging neurodevelopmental disease characterized by abundant epileptiform spikes during non-rapid eye movement (NREM) sleep accompanied by cognitive dysfunction. The mechanism of cognitive dysfunction is unknown, but treatment with high-dose diazepam may improve symptoms. Spike rate does not predict treatment response, but spikes may disrupt sleep spindles. We hypothesized that in patients with EE-SWAS: (1) spikes and spindles would be anti-correlated, (2) high-dose diazepam would increase spindles and decrease spikes, and (3) spindle response would be greater in those with cognitive improvement.

METHODS

Consecutive EE-SWAS patients treated with high-dose diazepam that met the criteria were included. Using a validated automated spindle detector, spindle rate, duration, and percentage were computed in pre- and post-treatment NREM sleep. Spikes were quantified using a validated automated spike detector. The cognitive response was determined from a chart review.

RESULTS

Spindle rate was anti-correlated with the spike rate in the channel with the maximal spike rate (p = 0.002) and averaged across all channels (p = 0.0005). Spindle rate, duration, and percentage each increased, and spike rate decreased, after high-dose diazepam treatment (p ≤ 2e-5, all tests). Spindle rate, duration, and percentage (p ≤ 0.004, all tests) were increased in patients with cognitive improvement after treatment, but not those without. Changes in spindle rate but not changes in spike rate distinguished between groups.

INTERPRETATION

These findings confirm thalamocortical disruption in EE-SWAS, identify a mechanism through which benzodiazepines may support cognitive recovery, and introduce sleep spindles as a promising mechanistic biomarker to detect treatment response in severe epileptic encephalopathies.

Preliminary evidence of a relationship between sleep spindles and treatment response in epileptic encephalopathy

Objective

Epileptic encephalopathy with spike wave activation in sleep (EE-SWAS) is a challenging neurodevelopmental disease characterized by abundant epileptiform spikes during non-rapid eye movement (NREM) sleep accompanied by cognitive dysfunction. The mechanism of cognitive dysfunction is unknown, but treatment with high-dose diazepam may improve symptoms. Spike rate does not predict treatment response, but spikes may disrupt sleep spindles. We hypothesized that in patients with EE-SWAS: 1) spikes and spindles would be anticorrelated, 2) high-dose diazepam would increase spindles and decrease spikes, and 3) spindle response would be greater in those with cognitive improvement.

Methods

Consecutive EE-SWAS patients treated with high-dose diazepam that met criteria were included. Using a validated automated spindle detector, spindle rate, duration, and percentage were computed in pre- and post-treatment NREM sleep. Spikes were quantified using a validated automated spike detector. Cognitive response was determined from chart review.

Results

Spindle rate was anticorrelated with spike rate in the channel with the maximal spike rate ( p =0.002) and averaged across all channels ( p =0.0005). Spindle rate, duration, and percentage each increased, and spike rate decreased, after high-dose diazepam treatment ( p≤ 2e-5, all tests). Spindle rate, duration, and percentage ( p ≤0.004, all tests) were increased in patients with cognitive improvement after treatment, but not those without. Changes in spike rate did not distinguish between groups.

Interpretation

These findings confirm thalamocortical disruption in EE-SWAS, identify a mechanism through which benzodiazepines may support cognitive recovery, and introduce sleep spindles as a promising mechanistic biomarker to detect treatment response in severe epileptic encephalopathies.

Deep Brain Stimulation of the Centromedian Nucleus of the Thalamus for Lennox-Gastaut Syndrome: A Systematic Review and Individual Patient Data Analysis

BACKGROUND

Lennox-Gastaut syndrome (LGS) is a severe childhood-onset pharmacoresistant epilepsy. Deep brain stimulation (DBS) of the centromedian nucleus of the thalamus (CMN) has been utilized.

OBJECTIVE

To conduct a systematic review and individual patient data (IPD) analysis to characterize outcomes of DBS of CMN in LGS.

METHODS

PubMed, Embase, and Scopus were searched per Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Articles were screened by title/abstract then full text. Included articles were reviewed for bibliographic, demographic, and outcome data. IPD were extracted from studies providing IPD for all patients.

RESULTS

Of 72 resultant articles, 10 studies (114 patients) were included. Six of 7 studies reporting the outcome of ≥50% seizure reduction indicated that ≥50% of patients achieved this, with improved functional ability. Seizure freedom rate was generally <10%. Six studies with 47 patients provided IPD. The mean ages at epilepsy onset and CMN DBS were 3.9 ± 4.5 years and 17.4 ± 8.8 years, respectively. Nineteen of 41 (46.3%) patients had positive MRI findings. Seizure types included atypical absence in 39 (83.0%) patients, generalized tonic-clonic in 32 (68.1%), tonic in 22 (46.8%), and atonic in 20 (42.6%). Thirty-eight (80.9%) patients experienced ≥50% reduction in seizure frequency, and only 3 (6.4%) experienced seizure freedom. The mean seizure reduction was 62.9% ± 31.2% overall. Quality of life improved in 30/34 (88.2%) and was unchanged in the remainder (11.8%). The complication rate was 2/41 (4.9%). The mean length of follow-up was 19.8 ± 26.1 months (IQR: 4-18 months).

CONCLUSION

Limited data indicate that DBS of the CMN may be effective and safe for people with LGS.

18 F-FDG PET Brain Findings in a Case of Idiopathic Benign Rolandic Epilepsy of Childhood

Idiopathic benign rolandic epilepsy, also known as benign childhood epilepsy with centrotemporal spikes (BCECTS), is one of the commonly seen electroclinical epilepsy syndromes of childhood with a generally favorable long-term prognosis. We describe a 5-year-old female child who presented with recurrent focal seizures involving right side of face since the age of 6 months. She had no perinatal or postnatal insults, had normal development, and her neurological examination was unremarkable. Electroencephalogram showed rolandic spikes, suggesting BCETCS. Her seizures remained refractory to two appropriately dosed antiepileptic drugs. Magnetic resonance imaging of the brain did not reveal any structural lesion. Interictal fluorodeoxyglucose ¹⁸ F-positron emission tomography brain showed hypometabolism in the left lower rolandic region.

Electrical Status Epilepticus during Sleep and Evaluating the Electroencephalogram

Electrical status epilepticus during sleep (ESES) is an age-related, self-limited epileptic encephalopathy characterized by heterogeneous clinical manifestations and a specific electroencephalographic pattern of continuous spikes and waves during slow sleep. The etiology of ESES is not completely clear, although structural brain lesions, abnormal immunological markers, and genetic mutations have been associated with the syndrome. ESES was first described in 1971 and since then, the diagnostic criteria have changed multiple times. Additionally, inconsistency between authors in how to record and evaluate the electroencephalogram also leads to variability between studies. These inconsistencies hamper objectivity, comparison, and generalization. Because of this, one of the first priorities of physicians treating this condition should be defining the parameters of this disease so that cooperative building can occur.

GRIN2A and GRIN2B and Their Related Phenotypes

Glutamate is the most relevant excitatory neurotransmitter of the central nervous system; it binds with several receptors, including N-methyl-D-aspartate receptors (NMDARs), a subtype of ionotropic glutamate receptor that displays voltage-dependent block by Mg2+ and a high permeability to Ca2+. GRIN2A and GRIN2B genes encode the GluN2A and GluN2B subunits of the NMDARs, which play important roles in synaptogenesis, synaptic transmission, and synaptic plasticity, as well as contributing to neuronal loss and dysfunction in several neurological disorders. Recently, individuals with a range of childhood-onset drug-resistant epilepsies, such as Landau–Kleffner or Lennox–Gastaut syndrome, intellectual disability (ID), and other neurodevelopmental abnormalities have been found to carry mutations in GRIN2A and GRIN2B, with high variable expressivity in phenotype. The first one is found mainly in epilepsy-aphasia syndromes, while the second one mainly in autism, schizophrenia, and ID, such as autism spectrum disorders. Brain magnetic resonance imaging alterations are found in some patients, even if without a clear clinical correlation. At the same time, increasing data on genotype–phenotype correlation have been found, but this is still not fully demonstrated. There are no specific therapies for the treatment of correlated NMDARs epilepsy, although some evidence with memantine, an antagonist of glutamate receptor, is reported in the literature in selected cases with mutation determining a gain of function.

The safety, tolerability, and effectiveness of PTL-101, an oral cannabidiol formulation, in pediatric intractable epilepsy: A phase II, open-label, single-center study

INTRODUCTION

Several works have reported on the antiepileptic impact of cannabis-based preparations in patients with treatment-resistant epilepsy (TRE). However, current formulations suffer from low bioavailability and side effects. PTL-101, an oral formulation containing highly purified cannabidiol (CBD) embedded in seamless gelatin matrix beadlets was designed to enhance bioavailability and maintain a constant gastrointestinal transit time.

METHODS

This phase II, prospective study was open to pediatric patients with TRE on stable antiepileptic drugs' (AEDs) doses, who experienced ≥4 seizures within four weeks of enrolment and with a history of ≥4 AEDs failing to provide seizure control. Following a 4-week observation period, patients began a 2-week dose-titration phase (up to ≤25mg/kg or 450mg, the lower of the two), followed by a 10-week maintenance treatment period. Caregivers recorded seizure frequency, type, and severity and ranked their global impressions after 7 and 12weeks of treatment. Responders were those showing a ≥50% reduction from baseline monthly seizure frequency. Safety assessments monitored vital signs, adverse effects, physical and neurological exams, and laboratory tests.

RESULTS

Sixteen patients (age: 9.1±3.4) enrolled in the study; 11 completed the full treatment program. The average maintenance dose was 13.6±4.2mg/kg. Patient adherence to treatment regimens was 96.3±9.9%. By the end of the treatment period, 81.9% and 73.4±24.6% (p<0.05) reductions from baseline median seizure count and monthly seizure frequency, respectively, were recorded. Responders' rate was 56%; two patients became fully seizure-free. By study end, 8 (73%) caregivers reported an improved/very much improved condition, and 9 (82%) reported reduced/very much reduced seizure severity. Most commonly reported treatment-related adverse effects were sleep disturbance/insomnia, (4 (25.0%) patients), followed by somnolence, increased seizure frequency, and restlessness (3 patients each (18.8%)). None were serious or severe, and all resolved.

CONCLUSIONS

PTL-101 was safe and tolerable for use and demonstrated a potent seizure-reducing effect among pediatric patients with TRE.

Trends in sodium valproate prescriptions among children aged 0 to 14 years between 2010 and 2016: A study based on the French National Health Insurance Database

PURPOSE

After a huge campaign of information on the teratogenic risk of sodium valproate (VPA) having taken place in France we aimed to evaluate the trend of its prescriptions in young epileptic girls.

METHOD

Using the French National Health Insurance Database we searched for patients aged 0-14 years being supplied an antiepileptic drug (AED) between 2010 and 2016.

RESULTS

113,362 children received at least one AED, 61,259 boys and 52,103 girls. Compared to 2010-2014 years, VPA was less prescribed in 2016 as first AED (29% vs 37.3% respectively). The difference between the two periods was greater for girls (-41%) than for boys (-12%).

CONCLUSION

The changing trend of VPA as first AED prescribed, particularly in girls, reflects published evidence in terms of safety.

Epidemiology of children with epilepsy at a tertiary referral centre in South Africa

PURPOSE

This retrospective observational hospital-based study assessed the characteristics of children with epilepsy in a sub-Saharan African tertiary service over a 10-year period.

METHODS

Children with a primary or secondary diagnosis of epilepsy seen during the study period were identified from the departmental database. Demographic and clinical data were collected from the database and available medical records.

RESULTS

Of 4701 children managed in the neurology service, 2407 children (51%) had epilepsy. The 2017 International League Against Epilepsy Classification of the Epilepsies was used to ascribe seizure and epilepsy type, epilepsy syndrome diagnosis and aetiologic categories. Forty-three percent of children had seizure onset before age one year. Focal Epilepsy occurred in 48% of the cohort (n = 1145). Twenty-five percent had an epilepsy syndrome diagnosis. Most children (54%) had epilepsy of unknown aetiology. Among those with underlying non-genetic aetiologies (33%), sequelae of intracranial infections, perinatal insults and structural brain malformations were most prevalent. Motor disability was present in 24% of children. Seventy-four percent had at least one associated motor disability, intellectual or learning disability, developmental delay or psychiatric comorbidity.

CONCLUSION

Epilepsy is common in sub-Saharan Africa. Many affected children have avoidable aetiologies. Compared to data from similar hospital-based studies in poorly resourced and resource-equipped settings, our cohort had a higher proportion of seizure onset below the age of one year and a greater number of infectious aetiologies, which is similar to population-based studies reported in sub-Saharan Africa. The presence of comorbidities is significant and demands greater advocacy for services for these children.

Early identification of epileptic encephalopathy with continuous spikes-and-waves during sleep: A case-control study

Epileptic encephalopathy with continuous spikes-and-waves during sleep (EE-CSWS) is a rare childhood epilepsy syndrome characterized by a regression in cognitive, behavioral and psychiatric functioning, seizures and a specific electroencephalographic pattern. An early recognition and an appropriate treatment might play a key role in the outcome of this epileptic encephalopathy. We conducted a case-control study to evaluate if there is any clinical or electroencephalographic sign suggestive of EE-CSWS after the first seizure. We retrospectively identified 10 EE-CSWS patients with available EEG recordings at time of the first seizure. We matched them with 10 controls from our first seizure clinics. All EEG recording were analyzed for the study. We did not find any clinical or EEG features that would suggest later development of EE-CSWS. As reported by others, the occurrence of multiple seizures types and a seizure worsening during the follow-up is more frequent in the cases than in the controls. These clinical criteria might be used as a red flag in clinical practice to identify the very few patients with EE-CSWS among the frequent patients with BECTS.

Overnight Video-Polysomnographic Studies in Children with Intractable Epileptic Encephalopathies

Background

The aim of this study was to assess sleep architecture and respiration during sleep in children with intractable epileptic encephalopathies using overnight video-polysomnography (V-PSG).

Material/Methods

Between 2015 to 2017 overnight V-PSG recordings were made for 31 children (22 boys and 9 girls) with intractable epileptic encephalopathy with a mean age of 6.78±3.61 years and a mean body mass index (BMI) of 15.83±3.16 kg/m³. Thirty-one healthy children were matched for sex, age, and BMI as the control group. The phases of sleep studied included rapid eye movement (REM) sleep, and non-REM (NREM) phases NREM 1, NREM 2, and NREM 3. Respiratory function during sleep was evaluated.

Results

Children with epileptic encephalopathies receiving antiepileptic treatment had significantly decreased total sleep time (TST) (p=0.038), significantly increased percentage of NREM1 (p=0.033), and a significantly lower percentage of total REM (p<0.0001), compared with the control group. All children 31/31 (100%) with epileptic encephalopathies had interictal epileptiform discharges, and 4/31 (12.9%) had ictal events. The number of respiratory events did not differ significantly between the two groups (p=0.118), but children in the epileptic encephalopathy group had a significantly shorter average duration (p=0.008) and longest duration (p=0.048) of respiratory events. Average (p=0.006) and least (p=0.0004) oxygen saturation (SatO₂) were significantly lower in children with epileptic encephalopathies compared with the control group.

Conclusions

Children with epileptic encephalopathies had altered sleep architecture and marked oxygen desaturation, which supports the need for referral of children with epileptic encephalopathy for overnight sleep evaluation.

Progress in unraveling the genetic etiology of rolandic epilepsy

Rolandic epilepsy (RE), or benign epilepsy of childhood with centrotemporal spikes (BECT), is the most frequent idiopathic partial epilepsy syndrome of childhood, where the "idiopathic" implies a genetic predisposition. Although RE has long been presumed to have a genetic component, clinical and genetic studies have shown a complex inheritance pattern. Furthermore, the underlying major genetic influence in RE has been challenged by recent reports of twin studies. Meanwhile, many genes or loci have been shown to be associated the RE/atypical RE (ARE) spectrum, with a higher frequency of causative variants in ARE. However, a full understanding of the genetic basis in the more common forms of the RE spectrum remains elusive.

[Genetics and treatment of early infantile epileptic encephalopathies]

Epileptic encephalopathies (EE) are the group of progressive conditions with various etiologies that can produce neurocognitive deficit both per se and due to constant epileptiform discharges. Epileptic encephalopathies constitute about 15% of epilepsy in childhood and 40% of all seizures occurring in the first 3 years of life. Ten syndrome forms of EE are identified. Genetic factors contribute to 70-80% of all epileptic diseases and approximately 40% of idiopathic epilepsies have a monogenic mode of inheritance. Thirty-five genes of EE have been identified and the search is still continuing. The marked genetic heterogeneity of early EE, including 16 with autosomal-dominant-, 13 with autosomal-recessive-, 4 with X-linked recessive- and 2 with X-linked autosomal inheritance, was shown. The article describes differentiated approaches to the treatment of certain EE syndromes. Recent publications record the effectiveness of targeted therapy for certain forms of monogenic early EE (stiripentol in SCN1A mutations, diphenine in SCN8A mutations, levetiracetam in STXBP1 mutations). These results indicate the necessity for accurate diagnosis of genetic variants in early infantile EE for preventive actions in burdened families and for increasing the effectiveness of treatment.

Syndrome of Electrical Status Epilepticus During Sleep: Epileptic Encephalopathy Related to Brain Development

BACKGROUND

Epileptic encephalopathy with electrical status epilepticus during sleep is an age-related and self-limited disorder. The present study analyzed the etiology, demographics, and pathogenesis of patients with electrical status epilepticus during sleep to provide information on the diagnosis and therapy of this syndrome.

METHODS

The etiologies of epileptic encephalopathy with electrical status epilepticus during sleep in patients admitted in Chinese People's Liberation Army General Hospital from 2009 to 2014 were retrospectively analyzed. Patients were classified into the genetic, structural-metabolic, and unknown groups according to the etiology. Demographics and clinical characteristics of all the patients were then analyzed and compared among groups.

RESULTS

The etiologies of epileptic encephalopathy with electrical status epilepticus during sleep in 75 patients mainly included benign childhood epilepsy with centrotemporal spikes, Landau-Kleffner syndrome, polymicrogyria, and migration disorders. Age at onset of epilepsy did not show a specific pattern, but age at onset of epileptic encephalopathy with electrical status epilepticus during sleep was concentrated at age 6-9 years. The mean age at onset of epilepsy in the genetic group was significantly older than that in the structural-metabolic group (P < 0.05). Age at onset of epileptic encephalopathy with electrical status epilepticus during sleep did not significantly differ between the two groups.

CONCLUSIONS

Electrical status epilepticus during sleep is an epileptic encephalopathy related to brain development and presents an age-dependent occurrence.

Epidemiology of epilepsy

Epilepsy is a burden affecting no fewer than 50 million patients worldwide. It is a heterogeneous group of disorders comprising both common and very rare forms, thus rendering its epidemiological investigations rather difficult. Moreover, making an epilepsy diagnosis per se can be challenging due to an evolving system of classification, and its dependency on local habits and culture. Any attempt at meta-analyses must consider such biases when pooling data from different centers and countries. Differentiating a contextual seizure from chronic epilepsy is every epileptologist's daily mission, yet it is also crucial for achieving a proper estimation of the epidemiology of epilepsy. Our present objective was to provide an overview of the epidemiology of both syndromic and non-syndromic epilepsy. Most epileptic syndromes tend to be rare and, thus, the feasibility of epidemiological quantification in populations is also addressed. Regarding its prevalence and cost, epilepsy deserves greater attention than it generally receives, as it appears to continue to be a condition under persistent taboos.

Benign childhood epilepsy with Centro-Temporal spikes (BCECTSs), electrical status epilepticus in sleep (ESES), and academic decline--how aggressive should we be?

Since many of the children with BCECTSs display electrical status epilepticus during sleep and many present with different comorbidities, mainly ADHD and behavioral disturbances, clinicians are often confronted with the dilemma of how aggressive they should be with their efforts of normalizing the EEG. We conducted a retrospective study by screening medical records of all consecutive patients with BCECTSs, spike-wave index (SWI) >30%, and ADHD/ADD that were evaluated in our pediatric epilepsy service and were followed up for at least two years. Patients with neurocognitive deterioration detected by formal testing were excluded. A total of 17 patients with mean age of 6.9years at BCECTS diagnosis were identified. The patients' mean SWI was 60% and that dense electrical activity lasted 1.5years on average (range: 1-4.5years). Six children were formally diagnosed with learning disabilities in addition to ADD/ADHD. All of them were treated with an average of three antiepileptic medications, mainly for the purpose of normalizing the EEG, but none of them was treated with steroids or high-dose diazepam. The mean duration of follow-up was 5.5years. A cognitive or behavioral deterioration was not detected in any of them. Our data suggest that when treating a child with BCECTSs, high SWI, and school difficulties, the most critical parameter that determines the necessity of using second-line antiepileptic agents such as steroids or high-dose diazepam is a formal psychological evaluation that proves cognitive (I.Q.) decline. Otherwise, these agents may be avoided.

Conceptualizing lennox-gastaut syndrome as a secondary network epilepsy

Lennox–Gastaut Syndrome (LGS) is a category of severe, disabling epilepsy, characterized by frequent, treatment-resistant seizures, and cognitive impairment. Electroencephalography (EEG) shows characteristic generalized epileptic activity that is similar in those with lesional, genetic, or unknown causes, suggesting a common underlying mechanism. The condition typically begins in young children, leaving many severely disabled with recurring seizures throughout their adult life. Scalp EEG of the tonic seizures of LGS is characterized by a diffuse high-voltage slow transient evolving into generalized low-voltage fast activity, likely reflecting sustained fast neuronal firing over a wide cortical area. The typical interictal discharges (runs of slow spike-and-wave and bursts of generalized paroxysmal fast activity) also have a “generalized” electrical field, suggesting widespread cortical involvement. Recent brain mapping studies have begun to reveal which cortical and subcortical regions are active during these “generalized” discharges. In this critical review, we examine findings from neuroimaging studies of LGS and place these in the context of the electrical and clinical features of the syndrome. We suggest that LGS can be conceptualized as “secondary network epilepsy,” where the epileptic activity is expressed through large-scale brain networks, particularly the attention and default-mode networks. Cortical lesions, when present, appear to chronically interact with these networks to produce network instability rather than triggering each individual epileptic discharge. LGS can be considered as “secondary” network epilepsy because the epileptic manifestations of the disorder reflect the networks being driven, rather than the specific initiating process. In this review, we begin with a summation of the clinical manifestations of LGS and what this has revealed about the underlying etiology of the condition. We then undertake a systematic review of the functional neuroimaging literature in LGS, which leads us to conclude that LGS can best be conceptualized as “secondary network epilepsy.”

Epilepsy surgery for early infantile epileptic encephalopathy (ohtahara syndrome)

Early infantile epileptic encephalopathy or Ohtahara syndrome is the earliest form of the age-dependent epileptic encephalopathies. Its manifestations include tonic spasms, focal motor seizures, suppression burst pattern, pharmaco-resistance, and dismal prognosis. The purpose of this study was to evaluate the effectiveness of epilepsy surgery in selected infants. We identified 11 patients, 9 from the literature and 2 from our institution that fulfilled diagnostic criteria of Ohtahara syndrome and had undergone epilepsy surgery in infancy. Seven of the 11 infants have remained seizure free (Engel class IA) and four are reportedly having rare to infrequent seizures (Engel class IIB). All patients experienced "catch up" development. In contrast to Ohtahara's15 pharmacotherapy managed patients, who had a mortality rate of approximately fifty percent, and those that survived continued to have seizures and were severely impaired, the outcome of selected surgically managed patients is much more favorable.

Continuous Spikes and Waves during Sleep: Electroclinical Presentation and Suggestions for Management

Continuous spikes and waves during sleep (CSWS) is an epileptic encephalopathy characterized in most patients by (1) difficult to control seizures, (2) interictal epileptiform activity that becomes prominent during sleep leading to an electroencephalogram (EEG) pattern of electrical status epilepticus in sleep (ESES), and (3) neurocognitive regression. In this paper, we will summarize current epidemiological, clinical, and EEG knowledge on CSWS and will provide suggestions for treatment. CSWS typically presents with seizures around 2-4 years of age. Neurocognitive regression occurs around 5-6 years of age, and it is accompanied by subacute worsening of EEG abnormalities and seizures. At approximately 6-9 years of age, there is a gradual resolution of seizures and EEG abnormalities, but the neurocognitive deficits persist in most patients. The cause of CSWS is unknown, but early developmental lesions play a major role in approximately half of the patients, and genetic associations have recently been described. High-dose benzodiazepines and corticosteroids have been successfully used to treat clinical and electroencephalographic features. Corticosteroids are often reserved for refractory disease because of adverse events. Valproate, ethosuximide, levetiracetam, sulthiame, and lamotrigine have been also used with some success. Epilepsy surgery may be considered in a few selected patients.

Prevalence of epilepsy in the People's Republic of China: a systematic review

To date there has not been a nationwide systematic analysis of the prevalence of epilepsy in China. The aim of this study was to estimate the prevalence of epilepsy in mainland China from the published studies and analyze the prevalence of epilepsy by survey method, gender, location, age, seizure type and prevalence of date. We searched the PubMed, Embase, Chinese Biological Medical Literature (CBM), Chinese National Knowledge Infrastructure (CNKI), Chinese Wanfang and Chongqing VIP databases for epidemiological studies on the prevalence of epilepsy. Thirty-eight studies were included that comprised a total sample size of 7,695,961, among whom 13,224 had epilepsy. The overall prevalence of epilepsy was 2.89‰. The prevalence of males and females were 3.83‰ and 3.45‰, respectively. The location-specific prevalence in urban and rural areas was 2.34‰ and 3.17‰, respectively. Prevalence by age groups, 0-9, 10-19, 20-29, 30-39, 40-49, 50-59, 60-69 and ≥70 were 2.21‰, 3.23‰, 3.14‰, 2.83‰, 2.96‰, 2.61‰, 2.76‰ and 2.22‰, respectively. In the subgroup analysis by prevalence date, prevalence rate of epilepsy ranged from 1.19‰ to 6.70‰. As for the seizure types, the overall prevalence of generalized seizures, partial seizures and unclassifiable seizures were 3.12‰, 0.57‰ and 0.23‰, respectively. Overall, the prevalence rate of epilepsy is different for each area in mainland China. A higher prevalence of epilepsy is found in the subgroup analysis by male, rural, age group of 10-19 and generalized seizures. However, more epidemiological studies are needed from other provinces to estimate the overall prevalence of epilepsy in mainland China.

Electrical status epilepticus in sleep: clinical presentation and pathophysiology

Electrical status epilepticus in sleep involves an electroencephalographic pattern where interictal epileptiform activity is potentiated in the transition from wakefulness to sleep. Near-continuous spikes and waves that occupy a significant proportion of nonrapid eye movement sleep appear as a result of sleep-potentiated epileptiform activity. This electroencephalographic pattern appears in different electroclinical syndromes that present three common characteristics with different degrees of severity: seizures, sleep-potentiated epileptiform activity, and neuropsychologic regression. Continuous spikes and waves during sleep comprise the severest epileptic encephalopathy in the electroclinical spectrum. Landau-Kleffner syndrome presents with intermediate severity. Some "benign" pediatric focal epileptic syndromes represent the mildest end of this continuum. Based on published data, we provide a framework for clinical and electrical events. The underlying mechanisms leading to sleep potentiation of epileptiform activity in electrical status epilepticus in sleep are incompletely understood. A genetic basis or acquired early developmental insult may disrupt the normal maturation of neuronal networks. These factors may dynamically alter normal processes of brain development, leading to an age-related pattern of electroclinical expression of electrical status epilepticus in sleep.

Epileptic encephalopathies in adults and childhood

Epileptic encephalopathies are motor-mental retardations or cognitive disorders secondary to epileptic seizures or epileptiform activities. Encephalopaties due to brain damage, medications, or systemic diseases are generally not in the scope of this definition, but they may rarely accompany the condition. Appropriate differential diagnosis of epileptic seizures as well as subclinical electroencephalographic discharges are crucial for management of seizures and epileptiform discharges and relative regression of cognitive deterioration in long-term followup. Proper antiepileptic drug, hormonal treatment, or i.v. immunoglobulin choice play major role in prognosis. In this paper, we evaluated the current treatment approaches by reviewing clinical electrophysiological characteristics of epileptic encephalopathies.

Epilepsy: Ever-changing states of cortical excitability

It has been proposed that the underlying epileptic process is mediated by changes in both excitatory and inhibitory circuits leading to the formation of hyper-excitable seizure networks. In this review we aim to shed light on the many physiological factors that modulate excitability within these networks. These factors have been discussed extensively in many reviews each as a separate entity and cannot be extensively covered in a single manuscript. Thus for the purpose of this work in which we aim to bring those factors together to explain how they interact with epilepsy, we only provide brief descriptions. We present reported evidence supporting the existence of the epileptic brain in several states; interictal, peri-ictal and ictal, each with distinct excitability features. We then provide an overview of how many physiological factors influence the excitatory/inhibitory balance within the interictal state, where the networks are presumed to be functioning normally. We conclude that these changes result in constantly changing states of cortical excitability in patients with epilepsy.

Ohtahara syndrome with emphasis on recent genetic discovery

Ohtahara syndrome or Early Infantile Epileptic Encephalopathy (EIEE) with Suppression-Burst, is the most severe and the earliest developing age-related epileptic encephalopathy. Clinically, the syndrome is characterized by early onset tonic spasms associated with a severe and continuous pattern of burst activity. It is a debilitating and early progressive neurological disorder, resulting in intractable seizures and severe mental retardation. Specific mutations in at least four genes (whose protein products are essential in lower brain's neuronal and interneuronal functions, including mitochondrial respiratory chains have been identified in unrelated individuals with EIEE and include: (a) the ARX (aristaless-related) homeobox gene at Xp22.13 (EIEE-1 variant); (b) the CDKL5 (SYK9) gene at Xp22 (EIEE-2 variant); (c) the SLC25A22 (GC1) gene at 11p15.5 (EIEE-3 variant); and (d) the Stxbp1 (MUNC18-1) gene at 9q34-1 (EIEE-4 variant). A yet unresolved issue involves the relationship between early myoclonic encephalopathy (EME-ErbB4 mutations) versus the EIEE spectrum of disorders.

Atonic variant of benign childhood epilepsy with centrotemporal spikes (atonic-BECTS): a distinct electro-clinical syndrome

PURPOSE

To describe the clinical and electroencephalographic features, treatment strategies and outcome in a series of children with the atonic variant of benign childhood epilepsy with centrotemporal spikes (atonic-BECTS).

MATERIAL AND METHODS

Out of the 148 patients with BECTS reviewed from January 2005 to June 2010 in our Institute, there were seven (5%) with atonic-BECTS. All underwent video EEG, high-resolution magnetic resonance imaging (MRI), neuropsychological evaluation and language assessment. Their progress was followed. In addition to sodium valproate, three were treated with steroids, followed by intravenous immunoglobulin (IVIG) when the seizures relapsed while tapering or after stopping the steroids.

RESULTS

All of the children had earlier onset (mean=2.4 years), increased frequency and increased duration of focal seizures compared to typical BECTS. Head drop and truncal sway due to axial or axiorhizomelic atonia occurring several times per day or week was the key manifestation. The atonic seizures worsened with carbamazepine in three, clonazepam in two and clobazam in one. When the atypical seizures commenced, some children developed one or more of the following problems: hyperactivity, attention deficit, clumsy gait, and mild cognitive or language dysfunction. Three children became seizure free, one on steroids and the other two on IVIG.

CONCLUSIONS

BECTS in children with an early age of onset and frequent and prolonged seizures is more likely to evolve into atonic-BECTS. Carbamazepine and some benzodiazepines may worsen these seizures. Three children became seizure free with immunomodulatory therapy, one on steroids and the other two on IVIG, and had complete resolution of the transient motor and cognitive impairment. Atonic-BECTS needs to be differentiated from Lennox-Gastaut syndrome since it is potentially treatable and children recover with no sequel. Although all the children in this series continued to be on treatment with sodium valproate it is currently undetermined whether they would have required to do so if followed up for an extended period of time.

The effect of levetiracetam on focal nocturnal epileptiform activity during sleep--a placebo-controlled double-blind cross-over study

Electric Status Epilepticus during Sleep (ESES) occurs in children with and without epilepsy. It may be related to disturbances as autism spectrum disorder, attention-deficit hyperactivity disorder and acquired aphasia (Landau-Kleffner syndrome). Antiepileptic drug (AED) treatment has been reported in small studies without placebo control. This study was designed to assess AED effect in a placebo-controlled double-blind cross-over study. Levetiracetam (LEV) was chosen based on clinical evidence. Eighteen patients fulfilled the inclusion criteria. The mean spike index at baseline was 56, falling to a mean of 37 at the end of the LEV treatment period. Assessed with a 2-way ANOVA, there is a significant treatment effect (p<0.0002). To the best of our knowledge, this is the first placebo-controlled double-blind cross-over study for any AED in patients with ESES. The effect of LEV is comparable with its effect in treatment of epileptic seizures.

Electroencephalography in clinical epilepsy research

Electroencephalography (EEG) remains central to the investigation of epilepsy. This review discusses two clinical problems at the temporal extremes of neurophysiologic recording: evaluation of the clinical significance of individual spike discharges in benign epilepsy of childhood with centrotemporal spikes (BECTS), and prolonged (several days) continuous EEG monitoring in the ICU. BECTS is misdiagnosed often, and probably mis-treated often as well. Though the long-term outcome is usually excellent, it remains unclear whether the individual epileptiform discharges have a clinical effect. Answering this question is difficult, in part because of the natural evolution of the epilepsy and its different appearance depending on wakefulness or sleep state, and also due to substantial methodologic problems in measuring short and long-term cognitive effects. Continuous EEG (CEEG) recording has grown remarkably over the last 10 years. It has proved crucial in the diagnosis of nonconvulsive status epilepticus (NCSE), especially in the ICU, given the usual lack of obvious clinical signs of seizures in most of these patients, many of whom are critically ill. Much progress has been made in agreeing on terminology for the EEG findings, but diagnosis is still complicated. More efficient and reliable technology is being developed to help process the massive amount of data captured by CEEG and make it more useful (and in a timely fashion) clinically. Still, it is not completely clear which patients should be monitored, for how long, and what is the best role for CEEG in assessing and adjusting treatment once the diagnosis has been made. Investigators are using CEEG to study "seizure burden," to help determine what are the long-term effects of nonconvulsive seizures and NCSE, and to help guide treatment and improve outcome.

A review of the relationships between Landau-Kleffner syndrome, electrical status epilepticus during sleep, and continuous spike-waves during sleep

The goal of this report is to review the relationships between Landau-Kleffner syndrome (LKS), electrical status epilepticus during sleep (ESES), and continuous spike-waves during sleep (CSWS). LKS is a clinical syndrome involving mainly acquired aphasia and sometimes seizures. Other clinical findings include cognitive impairments and global regression of behavior. The EEG may evolve from more benign conditions into ESES (or CSWS), seen in 50% of patients with LKS, or may also show focal findings. Seizures include atypical absence, generalized tonic-clonic, atonic, and partial motor attacks. Effective medications are discussed. The EEG patterns CSWS and ESES are likely equivalent terms. CSWS is used by some authors, and ESES by others. Patients with these patterns usually show mental retardation, seizures, and global regression. More benign EEG patterns, like focal discharges, may develop into these more severe generalized patterns, which are associated with atypical absences, negative myoclonus, and cognitive disturbances. Memory disorders are common, because the nearly continuous generalized discharges in sleep do not allow for the memory consolidation that also occurs during sleep. Medications and possible etiologies are discussed.

Rolandic epilepsy: an uncommon presentation with leg motor seizures

Rolandic epilepsy (RE) is the most common and one of the most benign epileptic syndromes of childhood. It is typically characterized by sleep-related orofacial seizures, of brief duration, of variable frequency, in otherwise healthy children. Electroencephalography (EEG) shows typical centrotemporal spike and spike-and-wave complexes, often bilateral and asynchronous, activated by sleep. Therapy is often unnecessary and seizures spontaneously end at puberty. Apart from typical orofacial localization, arm or more diffuse clonic jerks are frequently described by parents. More rare and probably underestimated are sensorimotor seizure localized to one leg. When such seizures represent the only type of seizures in RE, the exact recognition of this benign epileptic syndrome appears difficult, leading to unnecessary investigation and therapy. We describe six children, among 230 with RE, who presented leg sensorimotor seizures as the mainly type of ictal manifestations.

The prevalence and management of epilepsy in secondary school pupils with and without special educational needs

OBJECTIVES

The objectives of this paper were to (i) determine the prevalence of epilepsy (including the various epilepsies and epilepsy syndromes) in a secondary school population; and (ii) compare the management of epilepsy between secondary school pupils with and without special educational needs.

METHODS

Retrospective observational study of a 250, 000 population (West Cheshire Health District). Pupils attending secondary school with epilepsy over a 1-year period were identified from the local Child Health Computer, school nurse and DGH records. Health records were examined to determine the prevalence, characteristics and management of the epilepsy, and the presence of any special educational needs, other learning difficulties or physical disability.

RESULTS

The prevalence of epilepsy was 4.1 per 1000, being 10 times higher among adolescents who had special educational needs. Pupils with epilepsy and special educational needs had more poorly controlled epilepsy, but did not have a higher number of focal seizures nor were they taking a greater number of anti-epileptic drugs. A physical disability occurred five times more often in those with special educational needs and epilepsy. While epilepsy in pupils at mainstream school without special educational needs was better controlled, one-fifth of these subjects had poorly controlled epilepsy and a few also had physical disabilities.

CONCLUSIONS

Epilepsy is more challenging to control in adolescents with special educational needs attending special schools. However, some pupils in mainstream secondary schools had poorly controlled epilepsy even when they did not have recognized special educational needs. Health and education professionals working across the range of secondary school environments need to be able to support pupils with challenging epilepsy, many of whom will also have special educational needs and some a physical disability, as an increasing number of adolescents with these difficulties are being placed in mainstream schools.

"Epileptic encephalopathy" of infancy and childhood: electro-clinical pictures and recent understandings

There is growing interest in the diagnosis of cognitive impairment among children with epilepsy. It is well known that status of seizures control has to be carefully investigated because it can be sufficient "per se" to cause progressive mental deterioration conditions. Subclinical electroencephalographic discharges may have subtle effects on cognition, learning and sleep patterns, even in the absence of clinical or sub-clinical seizures. In this respect, electroencephalographic monitoring (long-term and nocturnal recording) and in particular an all night video-polysomnography (V-NPSG) record can be crucial to detect the presence of unrecognized seizures and/or an inter-ictal nocturnal EEG discharge increasing. Epileptic encephalopathies (EE) are a group of conditions in which the higher cognitive functions are deteriorate as a consequence of epileptic activity, which, in fact, consists of frequent seizures and/or florid and prolonged interictal paroxysmal discharges, focal or generalized. AEDs represent the first line in opposing the burden of both, the poor seizures control and the poor interictal discharges control, in the cognitive deterioration of EE affected children. Thus, to improve the long-term cognitive/behavioural prognosis in these refractory epileptic children, it should be taken into account both a good seizures control and a strict sleep control, choosing carefully antiepileptic drugs which are able to control not only seizures clinically recognizable but even the EEG discharges onset and its increasing and spreading during sleep. Here, we review the efficacy and safety of the newer AEDs that, to date, are used in the treatment of EE in infancy and childhood.

Features of a subset of children with complex partial epilepsy requiring combination therapy for effective seizure control

To identify children with complex partial seizures with increased risk for suboptimal seizure control with 1 medication, a computerized database containing all patients seen in the context of a single pediatric neurology practice was reviewed for patients with complex partial seizures. Participants included in analysis were then divided into groups; a group in whom seizure control was attained with a single medication (group 1) and a group for whom 2 or more medications were required for seizure control (group 2). Status epilepticus, developmental disabilities, and the presence of coexisting other seizures/types were also significantly different, with a higher predominance in group 2 children. Patients with status epilepticus, coexistent seizure types, and developmental disabilities should be identified and more carefully followed, with a lower threshold for starting these children on a combination of antiepileptic drugs adhered to.

Epileptic negative myoclonus as the presenting seizure type in rolandic epilepsy

Epileptic negative myoclonus is an uncommon seizure type characterized by a sudden, brief loss of muscle tone that may lead to falling. It has been associated largely with benign childhood epilepsy with centrotemporal spikes (rolandic epilepsy), although it may also be a feature of other epileptic syndromes. In patients with rolandic epilepsy, epileptic negative myoclonus usually appears during the course of the disease, well after a diagnosis of the epilepsy has been established. Described here are five patients with rolandic epilepsy in which the presenting seizure was falls due to epileptic negative myoclonus. Because developmental delay or neurocognitive problems were present in three of the children, it is possible that epileptic negative myoclonus may be misinterpreted as clumsiness-related falls in some children who actually have undiagnosed rolandic epilepsy.

Atypical presentations of benign childhood epilepsy with centrotemporal spikes: a review

Benign childhood epilepsy with centrotemporal spikes is the most common epileptic syndrome in childhood. Atypical forms of benign childhood epilepsy with centrotemporal spikes are common. The different atypical forms of the condition are believed to represent a continuum of the same underlying genetic mechanism. The atypical forms of benign childhood epilepsy with centrotemporal spikes include electrical status epilepticus in slow waves sleep, Landau-Kleffner syndrome, status epilepticus of benign childhood epilepsy with centrotemporal spikes, "classic" atypical form, and others. This review delineates the different forms with emphasis on the cognitive hazards of the more malignant types.

Neuropsychological deficits in childhood epilepsy syndromes

Seizure disorders are relatively common in childhood, and the International League Against Epilepsy (ILAE) provides a hierarchical classification system to define seizure types. At the final level of classification, specific epilepsy syndromes are defined that represent a complex of signs and symptoms unique to an epilepsy condition. The present review discusses the issues related to several of these epilepsy syndromes in childhood, including those classified as generalized idiopathic epilepsies (e.g., childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy), focal epilepsies (benign rolandic epilepsy, occipital epilepsy, temporal lobe epilepsy, frontal lobe epilepsy) and the "epileptic encephalopathies," including Dravet's Syndrome, West Syndrome, Lennox-Gastaut Syndrome, Myoclonic Astatic Epilepsy, and Landau-Kleffner Syndrome. For each syndrome, the epidemiology, clinical manifestations, treatments, and neuropsychological findings are discussed.

Neuropsychological deficits in childhood epilepsy syndromes

Seizure disorders are relatively common in childhood, and the International League Against Epilepsy (ILAE) provides a hierarchical classification system to define seizure types. At the final level of classification, specific epilepsy syndromes are defined that represent a complex of signs and symptoms unique to an epilepsy condition. The present review discusses the issues related to several of these epilepsy syndromes in childhood, including those classified as generalized idiopathic epilepsies (e.g., childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy), focal epilepsies (benign rolandic epilepsy, occipital epilepsy, temporal lobe epilepsy, frontal lobe epilepsy) and the "epileptic encephalopathies," including Dravet's Syndrome, West Syndrome, Lennox-Gastaut Syndrome, Myoclonic Astatic Epilepsy, and Landau-Kleffner Syndrome. For each syndrome, the epidemiology, clinical manifestations, treatments, and neuropsychological findings are discussed.