Levetiracetam Efficacy in Epileptic Syndromes with Continuous Spikes and Waves during Slow Sleep: Experience in 12 Cases

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.

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

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

Is sleep captured during a standard daytime EEG sufficient to diagnose Electrical Status Epilepticus in Sleep

Electrical Status epilepticus of sleep (SES) is an EEG pattern where there is significant activation of epileptiform activity in NREM sleep. A spike wave index (SWI) of > 80-85% is often labelled as typical SES. We aimed to explore if sleep during a standard daytime-EEG, as compared an overnight-EEG, was adequate to diagnose ESES. Ten children with daytime and overnight studies suggestive of SES were audited. SWI and Spike Wave Density (SWD) were calculated for 5-minute epochs of wake in the daytime and overnight study, as well daytime-EEG sleep and first and last NREM cycle in the overnight-EEG. SWI in daytime NREM was not significantly different from SWI in the first sleep cycle of the overnight study. SWI in the last sleep cycle was significantly lower than the first sleep cycle in the overnight-EEG. SWD was significantly higher in the first sleep cycle in the overnight-EEG than the daytime sleep and the last NREM cycle. SES may be diagnosed in NREM sleep from a daytime-EEG study. Larger studies are needed to explore the significance of the disparity between SWI and SWD in the first and last NREM cycles in the overnight study.

N-acetyl cysteine: A new look at its effect on PTZ-induced convulsions

INTRODUCTION/AIM

Epilepsy is widely investigated as a common neurological disease requiring pharmacologically effective agents. N-acetyl cysteine (NAC), has become a remarkable molecule with its role in both antioxidant and glutaminergic modulation. There are many points and processes waiting to be revealed regarding the role of NAC in epilepsy.

MATERIALS AND METHODS

Pentylenetetrazole (PTZ) was administered to induce seizures in a total number of 48 Sprague-Dawley rats. 35 mg/kg PTZ dose as a sub-convulsive dose was administered to 24 animals to monitor EEG changes, while 70 mg/kg PTZ dose which was a convulsive dose was administered to 24 animals to determine seizure-related behavioral changes with the Racine's scale. 30 min before the seizure-induced procedure, NAC was administered at doses of 300 and 600 mg/kg as pretreatment to investigate anti-seizure and anti-oxidative effects. The spike percentage, the stage of convulsion, and the onset time of the first myoclonic jerk were evaluated to determine the anti-seizure effect. Furthermore, its effect on oxidative stress was determined by measuring both malondialdehyde (MDA) level and superoxide dismutase (SOD) enzyme activity.

RESULTS

There was a dose-dependent reduction in the seizure stage and prolonged onset time of the first myoclonic jerk in rats with NAC pretreatment. EEG recordings resulted in a dose-dependent decrease in spike percentages. Moreover, the same dose-dependent changes were observed in oxidative stress biomarkers, both 300 mg/kg NAC and 600 mg/kg decreased MDA levels and ameliorated SOD activity.

CONCLUSION

We can report that 300 mg/kg and 600 mg/kg doses of NAC are promising with their reducing effect on convulsions and have a beneficial effect by preventing oxidative stress. In addition, NAC has been also determined that this effect is dose-dependent. Detailed and comparative studies are needed on the convulsion-reducing effect of NAC in epilepsy.

Efficacy of pulse intravenous methylprednisolone in epileptic encephalopathy: a randomised controlled trial

BACKGROUND

High-level evidence for using steroids in epileptic encephalopathy (EE), other than West syndrome (WS), is lacking. This study investigated the efficacy and safety of pulse intravenous methylprednisolone (IVMP) in EE other than WS.

METHODS

This is an open-label evaluator-blinded randomised controlled study. Children aged 6 months or more with EE other than WS were included. Eighty children were randomised into intervention and non-intervention groups with 40 in each group. At the first visit (T1) seizure frequency, electroencephalographic (EEG) and Vineland Social Maturity Scale (VSMS) were obtained, and antiseizure medication (ASM) were optimised. After 1 month (T2), subjects were randomised to intervention (ASM+3 months IVMP pulse) or non-intervention group (only ASM) with 40 subjects in each group. They were followed up for 4 months (T3) and assessed.

RESULTS

After 4 months of follow-up, 75% of patients receiving IVMP had >50% seizure reduction versus 15.4% in control group (χ2=28.29, p<0.001) (RR 4.88, 95% CI 2.29 to 10.40), median percentage change in seizure frequency (91.41% vs 10%, p<0.001), improvement in EEG (45.5% vs 9.4%, χ2=10.866, p=0.001) and social age domain of VSMS scores (Z=-3.62, p<0.001) compared with baseline. None of the patients in the intervention group had any serious side-effects.

DISCUSSION

Three-month pulse IVMP therapy showed significant improvement in seizure frequency, EEG parameters and VSMS scores, with no steroid-related serious adverse effects. It can be considered as a safe and effective add on treatment in children with EE other than WS.

TRIAL REGISTRATION NUMBER

CTRI/2019/02/017807.

Effectiveness of perampanel in the treatment of pediatric patients with focal epilepsy and ESES: A single-center retrospective study

Objective: To investigate the therapeutic effect and influencing factors of perampanel (PER) on electrical status epilepticus during sleep (ESES).

Methods: We retrospectively analyzed the clinical data of pediatric patients with focal epilepsy and ESES who were treated at the Epilepsy Center of Shengjing Hospital of China Medical University between January 2016 and March 2022. Changes in the spike wave index (SWI) after 24 weeks of PER add-on treatment were compared. Kaplan‒Meier survival analysis, the log-rank test and multivariate Cox regression analysis were performed.

Results: A total of 54 pediatric patients met the inclusion criteria, including 33 males and 21 females. The mean age at the diagnosis of epilepsy was 6.41 ± 2.14 years and at ESES diagnosis was 7.58 ± 2.40 years. The mean ESES duration before add-on PER was 25.31 ± 15.12 months. The mean age of the patients at add-on PER initiation was 9.69 ± 2.12 years. The ESES resolved in 29 children after 6 months of PER add-on treatment, and the response rate was 53.7%. Univariate analysis with the log-rank test showed that the therapeutic effect of PER differed according to the age at ESES diagnosis and ESES duration before add-on PER treatment. Multivariate Cox regression analysis showed that only ESES duration before PER administration was a risk factor for PER treatment failure, and the other factors had no effect on the therapeutic effect.

Conclusion: PER add-on treatment has a good therapeutic effect on ESES and can be used as an alternative to corticosteroid and benzodiazepines. The therapeutic effect of PER add-on treatment was not related to the dose. A longer ESES duration results in a worse therapeutic effect. Therefore, more aggressive treatment measures should be implemented for ESES.

Effect of antiepileptic drug levetiracetam on cochlear function

BACKGROUND

Levetiracetam (LEV, 5-100 mg/kg) has been shown to prevent audiogenic seizures in a dose-dependent manner. This chemical is known to bind to synaptic vesicle protein 2A and inhibit l-type calcium channels, affecting neurotransmitter release. We hypothesize that the drug prevents audiogenic seizures partially by affecting cochlear neural response.

METHODS

To test this hypothesis, rats were given 1000, 500, 50, or 0 mg/kg (saline control) LEV-injection. Distortion product otoacoustic emissions (DPOAE), reflecting outer hair cell (OHC) function, and cochlear compound action potentials (CAP), reflecting cochlear neural output, were recorded and compared pre- and post-LEV.

RESULTS

1000 mg/kg LEV-injection did not significantly affect DPOAE. The high dose LEV-injection, however, significantly reduced CAP amplitude resulting threshold shift (TS), prolonged CAP latency, and enhanced CAP forward masking. CAP latency and forward masking were significantly affected at the 500 mg/kg dose, but CAP-TS remained unchanged after LEV-injection. Interestingly, CAP latency wassignificantly prolonged, at least at the low stimulation levels, although the amplitude of CAP remained constant after a clinical dose of LEV-injection (50 mg/kg).

DISCUSSION

Since the clinical dose of LEV-injection does not reduce CAP amplitude, the reduction of cochlear neural output is unlikely to be the underlying mechanism of LEV in the treatment of audiogenic seizure. The delayed cochlear neural response may be partially related to the prevention of audiogenic seizure. However, neuropharmacological changes in the central nervous system must play a major role in the treatment of audiogenic seizure, as it does in the treatment of focal epilepsy.

Electrical status epilepticus in sleep: The role of thalamus in etiopathogenesis

PURPOSE

In patients diagnosed with epilepsy, decreased ratio of N-acetyl aspartate to creatine (NAA/Cr) measured in magnetic resonance spectroscopy (MRS) has been accepted as a sign of neuronal cell loss or dysfunction. In this study, we aimed to determine whether a similar neuronal cell loss is present in a group of encephalopathy with electrical status epilepticus in sleep (ESES) patients METHODS: We performed this case-control study at a tertiary pediatric neurology center with patients with ESES. Inclusion criteria for the patient group were as follows: 1) a spike-wave index of at least 50%, 2) acquired neuropsychological regression, 3) normal cranial MRI. Eventually, a total of 21 patients with ESES and 17 control subjects were enrolled in the study. MRI of all control subjects was also within normal limits. 3D Slicer program was used for the analysis of thalamic and brain volumes. LCModel spectral fitting software was used to analyze single-voxel MRS data from the right and left thalamus of the subjects.

RESULTS

The mean age was 8.0 ± 1.88 years and 8.3 ± 1.70 years in ESES patients and the control subjects. After correcting for the main potential confounders (age and gender) with a linear regression model, NAA/Creatine ratio of the right thalamus was significantly lower in the ESES patient group compared to the healthy control group (p = 0.026). Likewise, the left thalamus NAA/Cr ratio was significantly lower in the ESES patient group than the healthy control group (p = 0.007). After correcting for age and gender, right thalamic volume was not statistically significantly smaller in ESES patients than in healthy controls (p = 0.337), but left thalamic volume was smaller in ESES patients than in healthy controls (p = 0.024).

CONCLUSION

In ESES patients, the NAA/Creatine ratio, which is an indicator of neuronal cell loss or dysfunction in the right and left thalamus, which appears regular on MRI, was found to be significantly lower than the healthy control group. This metabolic-induced thalamic dysfunction, which was reported for the first time up to date, may play a role in ESES epileptogenesis.

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.

Corpus callosotomy in pediatric patients with non-lesional epileptic encephalopathy with electrical status epilepticus during sleep

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Corpus callosotomy (CC) was performed in 3 pediatric patients with refractory epileptic encephalopathy with ESES.

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IQ was improved after CC with complete resolution of ESES in one patient.

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Developmental regression ceased after CC with worthwhile seizure reduction and temporary improvement of ESES in 2 patients.

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Epileptiform discharges disappeared or became lateralized after CC.

Epileptic encephalopathy with electrical status epilepticus during sleep (ESES) is often refractory to medical treatment and leads to poor cognitive outcomes. Corpus callosotomy may be an effective treatment option for drug-resistant ESES with no focal etiology. We retrospectively identified three patients who underwent corpus callosotomy for drug-resistant ESES in our institution. Electroencephalography (EEG) findings and cognitive functions were evaluated before surgery, at 3 months, 6 months, 1 year, and 2 years after surgery. Age at surgery was 6 years 10 months, 7 years 9 months, and 8 years 4 months, respectively. Period between the diagnosis of ESES and surgery ranged from 7 to 25 months. All patients had no obvious structural abnormalities and presented with cognitive decline despite multiple antiseizure medications and steroid therapies. One patient showed complete resolution of ESES and an improvement of intelligence quotient after surgery. Epileptiform EEG was lateralized to one hemisphere after surgery and spike wave index (SWI) was decreased with moderate improvement in development and seizures in the other 2 patients. SWI re-exacerbated from 6 months after surgery, but without subsequent developmental regression in these 2 patients. Corpus callosotomy may become an important treatment option for drug-resistant ESES in patients with no structural abnormalities.

Levetiracetam monotherapy in children with epilepsy: Experience from a tertiary pediatric neurology center

OBJECTIVES

Levetiracetam (LEV) is a second-generation antiepileptic drug with high efficacy and tolerability in children and adults with epilepsy. We aimed to retrospectively assess the long-term efficacy, tolerability, and safety of LEV monotherapy in children with epilepsy.

METHODS

All patients who received LEV monotherapy at the Ankara University Children Hospital between January 2010 and June 2020 were evaluated. This retrospective pediatric cohort study determined the efficacy and safety of LEV monotherapy in 281 outpatients with epilepsy.

RESULTS

There were 281 patients, 50.5% female, aged 5 months to 18 years with a mean age of 9 years. Of these, 48% of patients had idiopathic epilepsy, 40.6% had symptomatic epilepsy, and 11,4% had cryptogenic/genetic epilepsy. Primary generalized seizures occurred in 61.6% of patients, focal seizures in 19.6%, both generalized and focal seizures in 15,3%, focal to bilateral tonic-clonic seizures in 2.5%, and undefined type of seizure in 1.1%. A total of 22.8% patients had an accompanying extra neurological disease, mostly cardiological and hematological. The range of final daily dose was 10-71 mg/kg/day, with mean 29.5 mg/kg/day. Duration of therapy ranged from 7 days to 96 months, with median 12 months (IQR: 6-22). For the all cohort, a 6th month retention rate was 81%, a 12th month retention rate was 71.4%, and a 24th month retention rate was 61.8%. Eighty five percent of the patients had a seizure reduction of at least 50% and 55.9% of patients remained seizure-free for median 12 months treatment duration with LEV monotherapy. Improvement of electroencephalography (EEG) findings was found in 42% of patients on control EEGs. A total of 67 adverse events were documented in 45 (16%) patients. The most common adverse events were behavioral problems such as aggression (n:18) and irritability (n:17). The discontinuation rate due to adverse events was 2.5%, and due to inefficacy was 5.3%.

CONCLUSION

The present study suggests that the high retention rates, high percentage of seizure reduction, the low discontinuation rate due to adverse events and inefficacy, and the relatively benign and transient profile of adverse events make LEV preferable as monotherapy in the pediatric population.

Spike-Wave Index Assessment and Electro-Clinical Correlation in Patients with Encephalopathy Associated with Epileptic State During Slow Sleep (ESES / CSWS); Single-Center Experience

PURPOSE

This study aimed to describe the electroclinical spectrum and neurocognitive outcome in children with epileptic encephalopathy with status epilepticus during sleep (ESES) according to the EEG patterns.

METHODS

Records of 48 (19 males, 29 females) patients with ESES/CSWS syndrome were retrospectively evaluated for data on sleep and awake EEGs, psychometric tests, and brain MRI. Patients with a spike-wave index (SWI) of at least 50 % in the NREM sleep EEG were included in the study. Electrophysiologic findings were separated into two groups based on SWI: SWI>85-100 % (typical ESES) and SWI < 85 % (atypical ESES). The neurocognitive prognosis was also evaluated in two groups; favorable and unfavorable.

RESULTS

The median age at the onset of ESES was 6 years and 5 months and ranged from 3 to 13 years. The median duration of follow-up after the ESES diagnosis was 57 months (range 24-150 months). Etiology was evaluated in three groups: symptomatic/structural, idiopathic, and unknown (cryptogenic). Twenty-seven (56.25 %) patients had atypical ESES patterns and 21 patients (43.75 %) had typical ESES patterns. Twenty-eight patients (58.3 %) had cognitive deterioration. Long term neurocognitive outcome was unfavorable in half of the patients. Symptomatic/structural etiology was more common in patients with unfavorable (p < 0.001) outcomes. The median age at the diagnosis of ESES (p < 0.001) was significantly earlier in the patients with unfavorable neurocognitive outcomes. The longer duration of ESES(p < 0.001), and the longer time between the onset of epilepsy and ESES (p = 0.039) was significantly associated with unfavorable outcomes. We found that patients with typical ESES had a higher risk for poor neurocognitive outcomes than patients with atypical ESES (OR: 31.096 [1.565-617.696]).

CONCLUSION

The long-term outcome of ESES is exceedingly variable. An unfavorable neurocognitive outcome seems to be related to ESES with a long-duration and early-onset epileptic activity, SWI ≥ 85 %, and etiology.

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

PURPOSE

To 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).

METHODS

This 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.

RESULTS

Based 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).

CONCLUSION

An 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.

Nocturnal events in children: When and how to evaluate

Nocturnal events of wide variety and concern are frequently reported by patients and their caregivers. To evaluate suspected abnormal events, primary care physicians must first be familiar with normal behaviors, movements and breathing patterns. Abnormal nocturnal events can then be categorized as nocturnal seizure, parasomnia, sleep-related movement disorder or sleep-related breathing disorder. Diagnoses in the above categories can be made clinically; however, it is important to know when to refer for additional evaluation. Comprehensive literature review was undertaken of nocturnal and sleep-related disorders. This guide reviews nocturnal seizures, normal and abnormal nonepileptic movements and behaviors, discusses broad indications for referral for electroencephalography (EEG) or polysomnography (PSG), and guides counseling and management for patients and their families, ultimately aiding in interpretation of both findings and prognosis. Epilepsy syndromes can result in seizures during sleep or adjacent periods of wakefulness. Parasomnias and sleep-related movement disorders tend to also occur in childhood and may be distinguished clinically. Referral to additional specialists for specific studies including EEG or PSG can be necessary, while other times a knowledgeable and vigilant clinician can contribute to a prompt diagnosis based on clinical features. Nocturnal events often can be managed with parental reassurance and watchful waiting, but treatment or evaluation may be needed. Sleep-related breathing disorders are important to recognize as they present very differently in children than in adults and early intervention can be life-saving. This review should allow both primary and subspecialty non-neurologic pediatric and adolescent health care providers to better utilize EEG and PSG as part of a larger comprehensive clinical approach, distinguishing and managing both epileptic and nonepileptic nocturnal disorders of concern while fostering communication across providers to facilitate and coordinate better holistic long-term care of pediatric and adolescent patients.

Sleep-dependent memory consolidation in children with self-limited focal epilepsies

OBJECTIVE

Children with self-limited focal epilepsies of childhood (SLFE) are known to show impaired memory functions, particularly in the verbal domain. Interictal epileptiform discharges (IED) in these epilepsies are more pronounced in nonrapid eye movement (NREM) sleep. Nonrapid eye movement sleep is crucial for consolidation of newly-encoded memories. Therefore, we hypothesize that sleep-dependent memory consolidation is altered in relation to IED in children with SLFE.

METHODS

We conducted a prospective case-control study. We applied a verbal (word pair) and a visuospatial (two-dimensional [2D] object location) learning task, both previously shown to benefit from sleep in terms of memory consolidation. Learning took place in the evening, and retrieval was tested in the morning after a night of sleep. Electroencephalogram (EEG) was recorded across night. After sleep-stage scoring, the spike-wave index (SWI) was assessed at the beginning and the end of sleep. Fourteen patients with SLFE (age: 5.5 to 11.6 years) were compared with 15 healthy controls (age: 6.8 to 9.1 years) examined in a previous study.

RESULTS

In contrast to healthy controls (mean: +12.9% recalled word pairs, p = .003, standard deviation (SD) = 12.4%), patients did not show overnight performance gains in the verbal memory task (mean: +6.4% recalled word pairs, p > .05, SD = 17.3) Neither patients nor controls showed significant overnight changes in visuospatial task performance. Spike-wave index was negatively correlated with recall performance in the verbal but not in the visuospatial task.

SIGNIFICANCE

We found evidence for impaired overnight improvement of performance in children with SLFE in a verbal learning task, with high SWI rates predicting low recall performance. We speculate that spike-waves hamper long-term memory consolidation by interfering with NREM sleep.

Self-limited epilepsy with centro-temporal spikes: A study of 46 patients with unusual clinical manifestations

PURPOSE

We retrospectively analyzed the seizure characteristics, EEG pattern, treatment, and outcome in a series of patients with self-limited epilepsy with centrotemporal spikes (SLECTS) who presented with unusual clinical manifestations.

METHOD

A retrospective, descriptive, multicenter study was conducted evaluating 46 patients with SLECTS who had seizures with an unusual semiology. We collected data from patients with SLECTS seen at eight Argentine centers between April 1998 and April 2018.

RESULTS

Thirteen patients (28.2 %) had seizures with affective symptoms characterized by sudden fright and autonomic disturbances and mild impairment of consciousness. Eleven patients (24.8 %) had frequent seizures characterized by unilateral facial sensorimotor symptoms, oropharyngolaryngeal manifestations, and speech arrest with sialorrhea only when awake. Seven patients (15.3 %) started with opercular epileptic status with unilateral or bilateral clonic seizures of the mouth with speech arrest and sialorrhea when awake and during sleep. Seven patients (15.3 %) had postictal Todd's paralysis after unilateral clonic seizures with facial and limb movements lasting between 60 min and 130 min. Six patients (13 %) had negative myoclonus, two in a unilateral upper limb, two in a unilateral lower limb, and the remaining two patients had frequent falls. One patient (2.1 %) had focal sensorimotor seizures characterized by unilateral numbness in the cheeks and one upper limb, additional to unilateral facial clonic seizures, speech arrest, and sialorrhea. The remaining patient (2.1 %) had sporadic focal tonic-dystonic seizures in the left upper limb only during sleep.

CONCLUSION

In our study, we found evidence of the existence of unusual clinical cases of SLECTS with typical EEG patterns and an excellent prognosis.

Pharmacological treatment for continuous spike-wave during slow wave sleep syndrome and Landau-Kleffner Syndrome

BACKGROUND

Continuous spike-wave during slow wave sleep syndrome (CSWS) and Landau-Kleffner syndrome (LKS) are two epileptic encephalopathies that present with neurocognitive regression, aphasia, and clinical seizures, typically presenting in children around five years of age. The pathophysiology of these conditions is not completely understood. Some studies suggest a common origin for both. No systematic reviews have assessed the efficacy of pharmacological interventions for these conditions.

OBJECTIVES

To assess the benefit and adverse effects of pharmacological interventions for the treatment of CSWS and LKS.

SEARCH METHODS

On 8 September 2020, we searched the Cochrane Register of Studies (CRS Web) and MEDLINE Ovid (1946 to September 04, 2020). We applied no language restrictions. CRS Web includes randomised or quasi-randomised, controlled trials from CENTRAL, PubMed, Embase, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform.

SELECTION CRITERIA

Randomised controlled trials, quasi-randomised controlled trials, and cluster-randomised trials comparing antiepileptic drugs alone, or with steroids or intravenous immunoglobulins, or both versus other antiepileptic drugs, or placebo, or no treatment, administered to children with CSWS and LKS. We planned to compare treatments for the two conditions separately.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies identified by the search strategy for inclusion. The primary outcomes considered in this review were neuropsychological-neurolinguistic functions.

MAIN RESULTS

Our search strategy yielded 18 references. Two review authors independently assessed all references. We did not find any completed studies to include. We identified one ongoing trial, which was terminated because of lack of enrolment.

AUTHORS' CONCLUSIONS

There was no evidence from trials to support or refute the use of pharmacological treatment for continuous spike-wave during slow wave sleep syndrome or Landau-Kleffner syndrome. Well-designed randomised controlled trials are needed to inform practice.

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

PURPOSE

Epileptic 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.

METHOD

A 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.

RESULTS

Fifty-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.

CONCLUSIONS

Despite 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.

Sulthiame add-on treatment in children with epileptic encephalopathy with status epilepticus: an efficacy analysis in etiologic subgroups

PURPOSE

Sulthiame (STM) has been recommended as an effective antiepileptic drug (AED) in children with epileptic encephalopathy with status epilepticus in sleep (ESES). The aim of this study is to evaluate the efficacy of STM add-on treatment in children with pattern of ESES with respect to the etiologic subgroup.

METHODS

Twenty-nine children with ESES pattern with three different etiologic subgroups (epileptic syndromes: 14, structural/infectious: 9, unknown: 6) who were given STM as add-on treatment were included into the study. The efficacy of STM was evaluated in terms of seizure control, electroencephalography (EEG) findings, need of the new AEDs after add-on STM, and behavioral and cognitive improvement.

RESULTS

The range of the follow-up duration after add-on STM treatment was between 5 and 51 months. At the end of 1 year of STM treatment, the most successful electrophysiologic improvement was identified in the well-defined epileptic syndrome group; epileptic syndrome, 71.4% (10/14); structural/infectious, 33.3% (3/9); and unknown, 0% (0/6). Patients who had complete response or persistent ESES pattern at the 3rd month were still in the same condition at the 6th and 12th months. However, the ESES pattern reappeared in 35.2% of the patients who had partial electrophysiological improvement at the 3rd month. In the epilepsy syndrome group, eight out of ten patients who had either complete or partial EEG response after 1 year of STM treatment displayed behavioral and cognitive improvement.

CONCLUSION

Sulthiame might be a valid add-on treatment of ESES especially in children with epilepsy syndromes.

[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.

Closed-Loop Acoustic Stimulation During Sleep in Children With Epilepsy: A Hypothesis-Driven Novel Approach to Interact With Spike-Wave Activity and Pilot Data Assessing Feasibility

Slow waves, the electroencephalographic (EEG) hallmark of deep sleep, can be systematically manipulated by acoustic stimulation: stimulation time-locked to the down phase of slow waves reduces, whereas stimulation time-locked to the up phase increases slow waves. Spike-waves during sleep seem to be related to slow waves, raising the question of whether spike-waves can be systematically influenced by such acoustic stimulation. In five pediatric patients, all-night EEG was recorded, combined with real-time slow wave detection. Throughout the night, acoustic stimulation was performed in a 3 × 5-min-block design (no stimulation—stimulation—no stimulation). Tones were applied time-locked either to the up or to the down phase of the detected slow waves in an alternating pattern. All patients tolerated the acoustic stimulation during sleep well. They showed high sleep quality and no signs of clinical or non-convulsive electrographic seizures. Our preliminary analysis shows no systematic effect of acoustic stimulation on spike-wave activity. Moreover, with our stimulation approach tones were distributed over a rather broad phase-range during the DOWN or UP stimulation and showed inter-individual differences in their distribution. In this study, we applied for the first time an acoustic closed-loop slow wave stimulation tool for a non-invasive manipulation of spike-wave activity. Thus, our pilot data show that closed-loop acoustic stimulation is feasible and well tolerated in children with spike wave activity during sleep. Improved precision in phase targeting and personalized stimulation parameters in a larger sample of subjects might be needed to show systematic effects.

Usefulness of perampanel with concomitant levetiracetam for patients with drug-resistant epilepsy

PURPOSE

The purpose was to evaluate the efficacy of treatment and the occurrence of aggression-related adverse events among children receiving perampanel (PER) with concomitant levetiracetam (LEV).

METHODS

Patients were selected according to the following criteria: 1) between 12 and 18 years old; 2) seizures refractory to at least 2 first-line drugs; 3) at least 4 seizures a month before PER administration; and 4) at least 12 months of follow-up. Patients were subdivided into groups with and without LEV as concomitant treatment. PER was administered at a dose of 2 mg/day, increasing by 2 mg/day every 2 weeks up to 12 mg/day if seizures appeared. In comparison with the baseline seizure frequency, response to PER treatment was classified as follows: complete cessation (100% seizure control); response (≥50% reduction in seizures); and exacerbation (≥50% increase in seizures). Responders were identified as patients showing complete cessation or response.

RESULTS

The study group comprised 39 outpatients with a mean age of 13.7 years at enrollment. Responder status was seen in 13 of the 19 patients with LEV and 4 of the 20 patients without LEV. PER appeared significantly more effective in patients with LEV than in those without LEV (p = 0.0076). Seizure-free status was significantly more frequent among patients with LEV (47.4%) than among those without LEV (15.0% (p = 0.0407)). Aggression was present in 2 patients without LEV, but none with LEV.

CONCLUSION

The present study suggests the utility of PER with concomitant LEV for children with drug-resistant epilepsy.

Levodropropizine suppresses seizure activity in rats with pentylenetetrazol-induced epilepsy

BACKGROUND

Millions of individuals worldwide suffer from epilepsy, and up to 25% of patients have seizures that are resistant to currently available antiepileptic drugs. Hence, there continues to be a need for more seizure medications that are effective yet tolerable. Levodropropizine (LVDP) is an established antitussive drug that, based on preclinical data, may also have antiepileptic activity.

METHODS

We treated rats with either intraperitoneal (IP) LVDP at two different doses or placebo in randomized fashion and then exposed them to IP pentylenetetrazol (PTZ), a potent seizure-inducing compound. We measured the rats' subsequent seizure activity with electroencephalography (EEG), Racine's convulsion scale (RCS) and time to first myoclonic jerk (TFMJ) to determine whether LVDP has antiepileptic properties in our murine model for epilepsy.

RESULTS

When compared to placebo, LVDP at both doses significantly suppressed seizure activity. Mean EEG spike wave percentage score decreased from 76.8% (placebo) to 13.1% (lower dose) and 7.6% (higher dose, bothp <  0.0001). RCS decreased from a mean of 5.8 (placebo) to 1.83 (lower dose) and 1.16 (higher dose, both p <  0.05). TFMJ had increased from a mean of 65.1 s (placebo), to 247.3 s (lower dose) and 295.5 s (higher dose, both p <  0.0001).

CONCLUSIONS

Levodropropizine, a common antitussive drug, suppresses seizure activity in rats with PTZ-induced status epilepticus. Given the ongoing need to find effective therapies for refractory epilepsy, the possibility of using levodropropizine as an antiepilepticshould be further explored.

Benign epilepsy with centrotemporal spikes: Correlating spike frequency and neuropsychology

OBJECTIVES

Neuropsychological sequelae are a feature of benign epilepsy with centrotemporal spikes (BECTS) in children. A correlation between the frequency of interictal EEG discharges and the cognitive as well as behavioral profile of the patients has been suspected but not proven.

MATERIALS AND METHODS

Children with BECTS that had not yet been treated were included into a randomized controlled trial. In the initial visit, EEGs were recorded. The frequency of interictal discharges was quantified. Correlations between the discharge frequency and the performance in a neuropsychological test battery were examined.

RESULTS

The cognitive test results were within or slightly above normal range (Culture-free intelligence test: 99.4%-confidence interval [CI]: [50.3, 59.9], test standardized to a population mean of 50). Parent-reported behavioral abnormalities were statistically significantly increased (CBCL total score CI: [51.9, 61.9], population mean as above). Correlations between the frequency of interictal epileptic discharges and the test results could not be identified (lowest encountered P-value: 0.034, not significant after correction for multiple testing).

CONCLUSION

The data do not support the hypothesis that the frequency of the interictal EEG discharges influences the neurocognitive performance or behavioral parameters of children with BECTS.

Highly selective SGLT2 inhibitor dapagliflozin reduces seizure activity in pentylenetetrazol-induced murine model of epilepsy

Background

Worldwide, over 10 million individuals suffer from drug-resistant epilepsy. New therapeutic strategies are needed to address this debilitating disease. Inhibition of sodium-glucose linked transporters (SGLTs), which are variably expressed in the brain, has been demonstrated to reduce seizure activity in murine models of epilepsy. Here we investigated the effects of dapagliflozin, a highly competitive SGLT2 inhibitor currently used as a drug for diabetes mellitus, on seizure activity in rats with pentylenetetrazol (PTZ) induced seizures.

Methods

Laboratory rats (n = 48) were evenly randomized into two experiments, each with four study arms: (1) a vehicle-treated (placebo) arm infused with saline; (2) a control arm infused with PTZ; (3) a treatment arm with PTZ and dapagliflozin at 75 mg/kg, and (4) another treatment arm with PTZ and dapagliflozin at 150 mg/kg. Study subjects were assessed for seizures either via EEG as measured by spike wave percentage (SWP), or clinically via Racine’s scales scores (RSS) and time to first myoclonic jerk (TFMJ).

Results

Rats treated with dapagliflozin had lower mean SWP on EEG (20.4% versus 75.3% for untreated rats). Behaviorally, treatment with dapagliflozin improved means RSS (2.33 versus 5.5) and mean TFMJ (68.3 versus 196.7 s). All of these findings were statistically significant with p-values of < 0.0001. There was a trend towards even better seizure control with the higher dose of dapagliflozin at 150 mg/kg, however this was not consistently statistically significant.

Conclusions

Dapagliflozin decreased seizure activity in rats with PTZ–induced seizures. This may be explained by the anti-seizure effects of decreased glucose availability and a reduction in sodium transport across neuronal membranes which can confer a stabilizing effect against excitability and unwanted depolarization. The potential clinical role of dapagliflozin and other SGLT2 inhibitors as anti-seizure medications should be further explored.

Treatment of Epileptic Encephalopathies: Current State of the Art

Childhood epileptic encephalopathies are age-dependent disorders of the brain whose hallmarks include loss of neurologic function over time, abnormal electroencephalographic findings, and seizures. Ictal and interictal electrographic activity are conjointly thought to be at the root of the often devastating neuropsychological deterioration, which is specific to the maturing brain. The goals of treatment are not only to control seizures, but also to prevent or reverse neurologic loss of function. In general, time is of the essence in diagnosis, and experienced specialists should promptly design a treatment plan. Hormonal and immune therapies are at the forefront of treatment in many cases, with traditional antiepileptic drugs and surgery (when an identifiable lesion is present) playing a limited role. However, gold standard evidence for treatment of epileptic encephalopathies remains limited. Ongoing clinical and basic research may lead to better understanding of these catastrophic conditions and to better and more effective therapies.

Topiramate in childhood epileptic encephalopathy with continuous spike-waves during sleep: A retrospective study of 21 cases

OBJECTIVE

Encephalopathy with continuous spike-wave during sleep (CSWS) is a particularly difficult-to-treat childhood epileptic syndrome. This study sought to present the EEG improvement and clinical efficacy of topiramate (TPM), a broad spectrum antiepileptic drug (AED), in a series of 21 children with CSWS encephalopathy.

METHODS

We retrospectively reviewed the EEG results and clinical data of children with CSWS followed-up in our institution and treated with TPM. Sleep EEGs were performed 0-3 months prior to TPM introduction and then at 3 and 12 months. The exclusion criteria were (1) introduction of another AED and (2) withdrawal of a potentially aggravating AED during the first 3 months of treatment. In addition to spike index (SI), the severity of EEG abnormalities was rated using an original scale that also considered the spatial extent of interictal epileptiform discharges.

RESULTS

21 patients were included (18 males, 4-14y, three symptomatic cases). At 3 months, sleep EEG was improved in 14 and normalized in four (TPM doses: 2-5.5 mg/kg/day). Among these 18 patients, 16 manifested cognitive or behavioural improvement. In a subgroup of seven patients with frequent seizures, five became seizure-free and one had over 75% decrease in seizure frequency. At the one-year follow-up, 20 children were still on TPM and 10 exhibited persistent EEG improvement without any other AED being introduced, most of them with clinical benefits.

CONCLUSION

TPM can decrease EEG abnormalities in epileptic encephalopathy with CSWS, achieving clinical improvement in the majority of patients. However, relapse may occur in the long-term in nearly half of cases. Otherwise, TPM has proven particularly useful in reducing seizure frequency in refractory cases.

ACTH has beneficial effects on stuttering in ADHD and ASD patients with ESES: A retrospective study

INTRODUCTION

Etiology of stuttering remains unknown and no pharmacologic intervention has been approved for treatment. We aimed to evaluate EEG parameters and the effect of adrenocorticotropic hormone (ACTH) therapy in stuttering.

METHODS

In this retrospective study, 25 patients with attention deficit and hyperactivity (ADHD) or autism spectrum disorder (ASD), and comorbid stuttering were followed and treated with ACTH for electrical status epilepticus in sleep (ESES). Sleep EEGs were recorded at referral and follow-up visits and short courses of ACTH were administered when spike-wave index (SWI) was ⩾15%. The assessment of treatment effectiveness was based on reduction in SWI, and the clinician-reported improvement in stuttering, and ADHD or ASD. Statistical analyses were conducted in order to investigate the relationship between the clinical and EEG parameters.

RESULTS

Following treatment with ACTH, a reduction in SWI in all the patients was accompanied by a 72% improvement in ADHD or ASD, and 83.8% improvement in stuttering. Twelve of the 25 patients with stuttering showed complete treatment response. Linear regressions established that SWI at final visit significantly predicted improvement in ADHD or ASD, and in stuttering. If symptoms had recurred, improvement was once again achieved with repeated ACTH therapies. Stuttering always improved prior to, and recurred following ADHD or ASD.

CONCLUSION

The underlying etiology leading to ESES may play a significant role in the pathophysiology of stuttering and connect stuttering to other developmental disorders. ACTH therapy has beneficial effects on stuttering and improves EEG parameters.

Immediate termination of electrical status epilepticus in sleep after hemispherotomy is associated with significant progress in language development

AIM

To study the effect of hemispherotomy on electrical status epilepticus in sleep (ESES) and language development.

METHOD

Children with a confirmed diagnosis of ESES prior to surgery and a minimum of 24 months of developmental follow-up data were compared with age-matched controls without ESES. Language quotients (LQs) were calculated before and after surgery.

RESULTS

Eleven patients (five females, six males) and 21 controls (11 females, 10 males) were included. Before surgery a significantly higher number of children in the study group (n=9) demonstrated severe developmental delay compared with children in the control group (n=13; p=0.015). In the study group ESES remitted immediately after surgery in 10 children, and a significant catch-up in LQs was observed in this group (preoperative mean 40.0 [standard deviation (SD) 22.2, interquartile range (IQR) 30.0-62.0]; postoperative mean 73.0 [SD 33.5, IQR 41.0-97.0]; p=0.037). There was no significant difference compared with controls at last follow-up after surgery (study group: five with severe impairment; control group: eight with severe impairment [p=0.971]). Overall, a favourable developmental outcome was associated with freedom from seizures (seizure-free group: median preoperative LQ 61.5, median postoperative LQ 78.0 [p=0.017]; seizure group: median preoperative LQ 35.5, median postoperative LQ 56.5 [p=0.273]) and antiepileptic drug withdrawal (off medication: median preoperative LQ 49.5, median postoperative LQ 78.0 [p=0.011]; on medication: median preoperative LQ 78.0, median postoperative LQ 83.5 [p=0.889]).

INTERPRETATION

Children with ESES showed significantly lower preoperative language abilities than children without ESES. In cases with remission of ESES after surgery, marked improvement in LQs was noticed. This improvement cannot be fully explained by seizure-freedom alone as seizure-free children without preoperative ESES showed less improvement.

Inhibitor effect of paricalcitol in rat model of pentylenetetrazol-induced seizures

Vitamin D has various systemic effects on bone metabolism, modulation of the immune system, stabilization of the cell membrane, oxidative stress, inflammation, apoptosis, and various other hormones. Differing from active vitamin D, paricalcitol is a relatively safe VDR agonist due to its relatively few side effects. This study has investigated the anticonvulsant effect of paricalcitol in convulsions induced by pentylenetetrazole (PTZ). 36 male Sprague-Dawley rats were divided randomly into two groups: 18 for EEG recording (PTZ 35 mg/kg) and 18 for behavioral studies (PTZ 70 mg/kg). Forty-five minutes before the PTZ injection, both groups of rats were given 5 and 10 μg/kg of paricalcitol i.p., respectively. Racine convulsion scores, first myoclonic jerk time, spike percentages, and antioxidant status were evaluated in the groups. Our results showed that the Racine's Convulsion Scale (RCS) score significantly dropped in the paricalcitol-treated group, analysis of the first myoclonic jerk (FMJ) latencies demonstrated a significantly longer latency in the paricalcitol-applied group, and spike percentages at EEG recordings significantly decreased with paricalcitol. Moreover, MDA levels were lower and SOD activity were higher in the 5 μg/kg paricalcitol group compared to the saline group; these results were more prominent in 10 μg/kg paricalcitol group. Our study has demonstrated that paricalcitol has protective effects on PTZ-induced convulsions. Based on the SOD and MDA levels in our study, these effects may result from the antioxidant characteristics of paricalcitol.

Longitudinal stability of interictal spikes in benign epilepsy with centrotemporal spikes

OBJECTIVE

To describe the natural history of electroencephalography (EEG) changes in patients with benign epilepsy with centrotemporal spikes (BECTS) over 1 year.

METHODS

Centrotemporal spikes were visually evaluated based on 24-h ambulatory EEG studies to determine the total, left, right, and bilateral centrotemporal spikes patients were awake and asleep. These spike rates were then used to compare the entire night of sleep to the first 2 h of sleep, the repeatability of spike frequency over two recordings (done within days to weeks), and longitudinal changes in spike rate over 6 and 12 months.

RESULTS

Nineteen children with newly diagnosed and untreated BECTS were included in this analysis. An excellent correlation was found between the centrotemporal spike rate during the entire duration of sleep and the first 2 h of sleep (intraclass correlation [ICC] 0.87, 95% confidence interval [CI] 0.67-0.95). In addition, an excellent correlation was found between two recordings completed an average of 23 days apart while patients were asleep (ICC 0.92, 95% CI 0.80-0.97) and good correlation while patients were awake (ICC 0.70, 95% CI 0.39-0.87). The average change in spike rate between recordings at baseline and at 6 months was a decrease of 64.7% (range -100% to +51.5%, p = 0.01) and the average change in rate between recordings at baseline and at 12 months was a decrease of 57.7% (range -100% to +29.1%, p = 0.01). In addition, within 6 months, most children had decreased centrotemporal rates, with 30% of children being spike-free. This absence of spikes did not continue in all children, since the majority (60%) had some spikes at 1 year following diagnosis.

SIGNIFICANCE

Centrotemporal spike rates during sleep are stable when compared over days to weeks; however, when comparing spike rates over months there is a larger degree of variability.

Should epileptiform discharges be treated?

To evaluate the impact of epileptiform discharges (EDs) that do not occur within seizure patterns--such as spikes, sharp waves or spike waves--on cognitive function and to discuss the circumstances under which treatment of EDs might be considered. Methods used in this article is "Review of the literature". EDs may disrupt short-term cognition in humans. Frequent EDs for a prolonged period can potentially impair long-term cognitive function in humans. However, there is conflicting evidence on the impact of EDs on long-term cognitive outcome because this relationship may be confounded by multiple factors such as underlying etiology, seizures, and medication effects. Limitations of existing studies include the lack of standardized ED quantification methods and of widely accepted automated spike quantification methods. Although there is no solid evidence for or against treatment of EDs, a non-evidence-based practical approach is suggested. EDs in otherwise asymptomatic individuals should not be treated because the risks of treatment probably outweigh its dubious benefits. A treatment trial for EDs may be considered when there is cognitive dysfunction or regression or neurologic symptoms that are unexplained by the underlying etiology, comorbid conditions, or seizure severity. In patients with cognitive or neurologic dysfunction with epilepsy or EDs, treatment may be warranted to control the underlying epileptic syndrome. EDs may cause cognitive or neurologic dysfunction in humans in the short term. There is conflicting evidence on the impact of EDs on long-term cognitive outcome. There is no evidence for or against treatment of asymptomatic ED.

Effects of antiepileptic drugs on interictal epileptiform discharges in focal epilepsies: an update on current evidence

Interictal epileptiform discharges (IEDs), occurring in the electroencephalograms (EEG) of patients with focal epilepsy, are crucial for diagnosis, while their relationship with seizure severity and recurrence is controversial. The effects of antiepileptic drugs (AEDs) on IEDs are even more debated. In general, it is currently believed by experts in the field that most of the classical AEDs do not significantly affect IEDs occurrence in these patients, and that monitoring their EEG effects during treatment is useless. In this review, we update the existing literature on the effects of classical and newer AEDs on focal IEDs, emphasizing the scarcity of data concerning the latter. We also discuss potential limits of available clinical and experimental data and future perspectives.

Montelukast inhibits pentylenetetrazol-induced seizures in rats

Background

Montelukast is an antiinflammatory drug with an antioxidant property. In this study, we aimed to reveal whether montelukast has a preventive effect against seizures and post-seizure oxidative stress in pentylenetetrazol (PTZ)-induced seizures in rats.

Material/Methods

Of the 48 male Sprague-Dawley rats used in the study, 24 were assigned to EEG recordings (group A) and 24 were assigned to behavioral studies (group B). In group A, the electrodes were implanted on dura over the left frontal cortex for EEG recording. After 10 days, in group A, i.p. saline, 25, 50, or 100 mg/kg montelukast+35 mg/kg PTZ was administered to the rats. EEG was recorded and spike percentage was evaluated. In group B, i.p. saline, 25, 50, or 100 mg/kg montelukast+70 mg/kg PTZ was administered to the rats. Racine’s Convulsion Scale (RCS) and onset times of first myoclonic jerk (FMJ) was used to evaluate the seizures. Malondialdehyde (MDA) and superoxide dismutase (SOD) levels were determined in the brain tissue of animals.

Results

Animals treated with 50 or 100 mg/kg montelukast had significantly lower RCS and significantly increased FMJ onset time compared to the saline-treated animals. Moreover, groups given 25, 50, or 100 mg/kg montelukast had significantly lower MDA and higher SOD levels compared to the saline-treated group. The differences were more pronounced in the 100 mg/kg montelukast-pretreated group (p<0.001).

Conclusions

Montelukast showed anticonvulsant action and led to amelioration of oxidative stress markers in PTZ-induced seizures in rats.

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.

Levetiracetam efficacy in children with epilepsy with electrical status epilepticus in sleep

PURPOSE

Epilepsy with electrical status epilepticus in sleep (ESES) is a devastating disease, and we sought to evaluate the efficacy of levetiracetam (LEV) for the treatment of patients with this epileptic encephalopathy in China.

METHODS

Clinical data from all patients with ESES who received LEV therapy at our pediatric neurology outpatient clinic between 2007 and 2014 (n=71) were retrospectively analyzed. The LEV dosage was 30-50mg/kg/day. Electroencephalography recordings and neuropsychological evaluations were performed repeatedly for 3-75months after the start of LEV therapy.

RESULTS

Thirty-five (70%) of 50 patients who had seizures at the start of LEV therapy had a >50% reduction in seizure frequency. Positive response on EEG was found during the first 3-4months of LEV therapy in 32 (45%) of 71 patients, with normalization of EEG in 5 patients. Relapse occurred in 8 (25%) of the initial electrical responders. Hence, 47 patients (66%) still suffered from ESES and only 13 patients regained their baseline level of function at the last follow-up. The response to LEV was significantly associated with ESES duration, age at onset of ESES, and etiology of epilepsy. Although fatigue and anorexia were the primary adverse events, LEV was well-tolerated by all patients.

CONCLUSIONS

Levetiracetam is safe and may be efficient when used to treat ESES syndrome; however, the efficacy EEG neuropsychological outcomes is limited on the whole.

Impaired sleep-related consolidation of declarative memories in idiopathic focal epilepsies of childhood

OBJECTIVE

Declarative memory is consolidated during sleep in healthy children. We tested the hypothesis that consolidation processes are impaired in idiopathic focal epilepsies (IFE) of childhood in association with frequent interictal epileptiform discharges (IEDs) during sleep.

METHODS

A verbal (word-pair association) and a nonverbal (2D object location) declarative memory task were administrated to 15 children with IFEs and 8 control children 6-12 years of age. Patients had either centrotemporal (11 patients) or occipital (4 patients) IEDs. All but 3 patients had a history of unprovoked seizures, and 6 of them were treated with valproate (VPA). The learning procedure (location of object pairs presented on a grid; association of word pairs) was executed in the evening. Retrieval was tested immediately after learning and on the next morning after a night of sleep. Participants were tested twice, once in natural home conditions and one month later in the unfamiliar conditions of the sleep unit under EEG monitoring.

RESULTS

Overnight recall performance was lower in children with IFE than in control children on both tasks (ps<0.05). Performance in home conditions was similar to that in hospital conditions. Higher spike-wave index (SWI) during nonrapid eye movement (NREM) sleep was associated with poorer performance in the nonverbal task (p<0.05). Valproate treatment was not associated with overnight recall performance for both tasks (ps>0.05).

CONCLUSION

Memory consolidation is impaired in IFE of childhood. The association between higher SWI during NREM sleep and poorer nonverbal declarative memory consolidation supports the hypothesis that interictal epileptic activity could disrupt sleep memory consolidation.

Continuous spike and wave in slow-wave sleep in a patient with Rett syndrome and in a patient with Lhermitte-Duclos syndrome and neurofibromatosis 1

Continuous spike and wave in slow-wave sleep (CSWS) is an electroencephalographic (EEG) pattern characterized by generalized spike-wave discharges occurring for at least 85% of non-rapid eye movement (non-REM) sleep, with marked attenuation during rapid eye movement (REM) sleep. It has been described in a large number of structural and nonstructural neurologic conditions and is associated with epilepsy, behavioral disturbances, and severe neuropsychiatric impairment. We describe continuous spike and wave in slow-wave sleep in 2 patients (one with Rett syndrome and the other with Lhermitte-Duclos syndrome). To our knowledge, continuous spike and wave in slow-wave sleep has not been previously described in these conditions.

Encephalopathy with Electrical Status Epilepticus in Slow Wave Sleep – a review with an emphasis on regional (perisylvian) aspects

Aim.The aim of this article is to review criticaly the Electrical Status Epilepticus in Slow Sleep (ESES) phenomenon from a neurophysiological mechanisms aspect as well as terminological and classification issues.

Methods.The review includes all the relevant papers published during the last 43 years on the subject of ESES and Continous Spike – Wave in Sleep (CSWS).These papers were identified in various large databases via the internet.

Rewiev and remarks.ESES/CSWS phenomena can be held as a common final pathway originating from different etiologies, including patients with early brain damage (probably involving thalamic structures), but also patients without structural pathology as in atypical evolution of idiopathic regional childhood hyperexcitability syndromes (with Rolandic epilepsy as a prototype). There are hints that genetic predisposition might be an important factor in the development of this process. The two large patient groups (lesional and non-lesional) show the same EEG evolution and encephalopathic cognitive consequences. The sleep EEG activation can be held as a common endophenotype. ESES represents an extreme sleep activation/potentiation of the local/regional interictal discharges, enhancing them in frequency, territorial extension, intra and trans-hemispherial propagation, synchrony and continuity. This process is most probably not identical with the development of bilateral spike-wave pattern in „generalized” epilepsies which involves primarily or secondarily the thalamocortical system as it had been explored by Gloor (1979) for idiopathic generalized rpilepsy and Steriade and Amzica (2003) for different types of generalized spike and wave discharges.

Conclusions and syndromological embedding of ESES.In an overwhelming majority of the investigated cases, the maps of the single discharges constituting sleep activation are identical; with focal/regional interictal spikes followed by slow closing wave, as it is seen in childhood regional age dependent hyperexcitability syndromes (prototype of the centro-temporal spikes of Rolandic epilepsy). The main mechanism of the developing cognitive impairment is most probably the consequence of interference with plastic function of slow wave sleep by obliterating synaptic decline during sleep. Presently, the consensus and co-operative research is highly obstacled by the terminological chaos, the controversial definitions and views around this still striking and enigmatic phenomenon.

Neuropsychological implications of adjunctive levetiracetam in childhood epilepsy

INTRODUCTION

Levetiracetam (LEV) is an effective antiepileptic drug also used in childhood and adolescence. Literature data regarding the long-term effects of LEV in childhood epilepsy and based on extensive neuropsychological evaluations using standardized tools are still scanty. Our study aimed to address this topic.

MATERIALS AND METHODS

We studied 10 patients with epilepsy characterized by focal or generalized seizures (4 boys, 6 girls; mean age: 10 years 8 months; range: 6 years 2 months - 16 years 2 months), treated with adjunctive LEV during a follow-up of 12 months. In 6 patients electroencephalogram (EEG) showed continuous spike and waves during sleep. Using standardized tools, we performed seriated assessments of cognitive and behavioral functioning in relation to seizure and EEG outcome.

RESULTS

Six patients completed the trial after 12 months of treatment; 1 patient dropped out of the study after 9 months, 3 patients after 6 months. Adjunctive LEV was effective on seizures in 3/10 patients and on EEG in 2/10 patients, and was well tolerated in all examined cases. Overall, no worsening of cognitive or behavioral functions has been detected during the period of the study; even at 6 and 12 months from baseline, an improvement in patients' abstract reasoning has been found, that was not related to seizure or EEG outcome.

CONCLUSIONS

In our population of children and adolescents, LEV had no adverse cognitive or behavioral effects, short- or long-term. We found an improvement of abstract reasoning, regardless of seizure and EEG outcome.