A prospective study of levetiracetam efficacy in epileptic syndromes with continuous spikes-waves during slow sleep

Corticosteroids versus clobazam for treatment of children with epileptic encephalopathy with spike-wave activation in sleep (RESCUE ESES): a multicentre randomised controlled trial

BACKGROUND

Epileptic encephalopathy with spike-wave activation in sleep (EE-SWAS) is a rare syndrome associated with cognitive and behavioural regression. On the basis of mostly small observational and retrospective studies, corticosteroids and clobazam are often considered the most effective treatments for this syndrome. We aimed to compare cognitive outcomes of children with EE-SWAS 6 months after starting treatment with either corticosteroids or clobazam.

METHODS

We did a multicentre, randomised controlled trial at eight tertiary referral centres for rare epilepsies in seven European countries. Children were eligible to participate if they were aged 2-12 years, were diagnosed with EE-SWAS within 6 months before inclusion, and had not been treated with corticosteroids or clobazam previously. Participants were randomly assigned (1:1) to treatment with corticosteroids (either continuous treatment with 1-2 mg/kg per day of prednisolone orally or pulse treatment with 20 mg/kg per day of methylprednisolone intravenously for 3 days every 4 weeks) or clobazam (0·5-1·2 mg/kg per day orally). The primary outcome was cognitive functioning after 6 months of treatment, which was assessed by either the intelligence quotient (IQ) responder rate (defined as improvement of ≥11·25 IQ points) or the cognitive sum score responder rate (defined as improvement of ≥0·75 points). Safety was assessed by number of adverse events and serious adverse events. Data were analysed in the intention-to-treat population, which included all children as randomised who had primary outcome data available at 6 months. The trial is registered with the Dutch Trial Register, Toetsingonline, NL43510.041.13, and the ISRCTN registry, ISRCTN42686094. The trial was terminated prematurely because enrolment of the predefined number of 130 participants was deemed not feasible.

FINDINGS

Between July 22, 2014, and Sept 3, 2022, 45 children were randomly assigned to either corticosteroids (n=22) or clobazam (n=23); two children assigned clobazam dropped out before 6 months and were excluded from the intention-to-treat analysis. At the 6-month assessment, an improvement of 11·25 IQ points or greater was reported for five (25%) of 20 children assigned corticosteroids versus zero (0%) of 18 assigned clobazam (risk ratio [RR] 10·0, 95% CI 1·2-1310·4; p=0·025). An improvement of 0·75 points or more in the cognitive sum score was recorded for one (5%) of 22 children assigned corticosteroids versus one (5%) of 21 children assigned clobazam (RR 1·0, 95% CI 0·1-11·7, p=0·97). Adverse events occurred in ten (45%) of 22 children who received corticosteroids, most frequently weight gain, and in 11 (52%) of 21 children who received clobazam, most often fatigue and behavioural disturbances. Occurrence of adverse events did not differ between groups (RR 0·8, 95% CI 0·4-1·4; p=0·65). Serious adverse events occurred in one child in the corticosteroid group (hospitalisation due to laryngitis) and in two children in the clobazam group (hospitalisation due to seizure aggravation, and respiratory tract infection). No deaths were reported.

INTERPRETATION

The trial was terminated prematurely, and the target sample size was not met, so our findings must be interpreted with caution. Our data indicated an improvement in IQ outcomes with corticosteroids compared with clobazam treatment, but no difference was seen in cognitive sum score. Our findings strengthen those from previous uncontrolled studies that support the early use of corticosteroids for children with EE-SWAS.

FUNDING

EpilepsieNL, WKZ fund, European Clinical Research Infrastructure Network, and Ming fund.

Encephalopathy Associated with Electrical Status Epilepticus of Sleep (ESES): A Practical Approach

Encephalopathy associated with electrical status epilepticus of sleep (ESES) is an underdiagnosed epileptic encephalopathy syndrome. Though there is considerable controversy regarding the terminology of this condition, there is increasing acceptance of the term, 'encephalopathy associated with electrical status epilepticus of sleep,' as it implies a clinical component as well as EEG feature. Core EEG feature of sleep activation of epileptiform discharges temporarily associated with cognitive or behavioral regression in a child with epilepsy is sufficient to make a diagnosis of ESES. It is important to quantify the spike wave index (SWI) during awake state and sleep to assess for sleep activation. Since focal spikes are also included in the counting of SWI, some grading to assess the distribution of epileptiform discharges is suggested to obtain the complete sleep EEG picture. MRI of the brain does not show abnormality in a number of patients. But common structural lesions include perinatal vascular insults and cortical malformations. Response to treatment is usually variable, but highest success rate is reported with the steroids. Prognosis usually depends on the duration of ESES.

Treatment strategies for encephalopathy related to status epilepticus during slow sleep, a narrative review of the literature

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

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.

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.

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.

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.

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.

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.

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.