Corticosteroids versus clobazam in epileptic encephalopathy with ESES: a European multicentre randomised controlled clinical trial (RESCUE ESES*)

Efficacy and Safety of Pulse Intravenous Methylprednisolone in Pediatric Epileptic Encephalopathies: Timing and Networks Consideration

Background: Epileptic encephalopathies (EE) are characterized by severe drug-resistant seizures, early onset, and unfavorable developmental outcomes. This article discusses the use of intravenous methylprednisolone (IVMP) pulse therapy in pediatric patients with EE to evaluate its efficacy and tolerability. Methods: This is a retrospective study from 2020 to 2023. Inclusion criteria were ≤18 years at the time of IVMP pulse therapy and at least 6 months of follow-up. Efficacy and outcome, defined as seizure reduction > 50% (responder rate), were evaluated at 6 and 9 months of therapy, and 6 months after therapy suspension; quality of life (QoL) was also assessed. Variables predicting positive post-IVMP outcomes were identified using statistical analysis. Results: The study included 21 patients, with a responder rate of 85.7% at 6 and 9 months of therapy, and 80.9% at 6 months after therapy suspension. Variables significantly predicting favorable outcome were etiology (p = 0.0475) and epilepsy type (p = 0.0475), with the best outcome achieved in patients with genetic epilepsy and those with encephalopathy related to electrical status epilepticus during slow-wave sleep (ESES). All patients evidenced improvements in QoL at the last follow-up, with no relevant adverse events reported. Conclusions: Our study confirmed the efficacy and high tolerability of IVMP pulse therapy in pediatric patients with EE. Genetic epilepsy and ESES were positive predictors of a favorable clinical outcome. QOL, EEG tracing, and postural-motor development showed an improving trend as well. IVMP pulse therapy should be considered earlier in patients with EE.

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.

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.

Corticosteroids in childhood epilepsies: A systematic review

Corticosteroids have been used for the treatment of patients with epilepsy for more than 6 decades, based on the hypothesis of inflammation in the genesis and/or promotion of epilepsy. We, therefore, aimed to provide a systematic overview of the use of corticosteroid regimes in childhood epilepsies in line with the PRISMA guidelines. We performed a structured literature search via PubMed and identified 160 papers with only three randomized controlled trials excluding the substantial trials on epileptic spasms. Corticosteroid regimes, duration of treatment (days to several months), and dosage protocols were highly variable in these studies. Evidence supports the use of steroids in epileptic spasms; however, there is only limited evidence for a positive effect for other epilepsy syndromes, e.g., epileptic encephalopathy with spike-and-wave activity in sleep [(D)EE-SWAS] or drug-resistant epilepsies (DREs). In (D)EE-SWAS (nine studies, 126 patients), 64% of patients showed an improvement either in the EEG or in their language/cognition following various steroid treatment regimes. In DRE (15 studies, 436 patients), a positive effect with a seizure reduction in 50% of pediatric and adult patients and seizure freedom in 15% was identified; however, no recommendation can be drawn due to the heterozygous cohort. This review highlights the immense need for controlled studies using steroids, especially in DRE, to offer patients new treatment options.

International League Against Epilepsy classification and definition of epilepsy syndromes with onset in childhood: Position paper by the ILAE Task Force on Nosology and Definitions

The 2017 International League Against Epilepsy classification has defined a three-tier system with epilepsy syndrome identification at the third level. Although a syndrome cannot be determined in all children with epilepsy, identification of a specific syndrome provides guidance on management and prognosis. In this paper, we describe the childhood onset epilepsy syndromes, most of which have both mandatory seizure type(s) and interictal electroencephalographic (EEG) features. Based on the 2017 Classification of Seizures and Epilepsies, some syndrome names have been updated using terms directly describing the seizure semiology. Epilepsy syndromes beginning in childhood have been divided into three categories: (1) self-limited focal epilepsies, comprising four syndromes: self-limited epilepsy with centrotemporal spikes, self-limited epilepsy with autonomic seizures, childhood occipital visual epilepsy, and photosensitive occipital lobe epilepsy; (2) generalized epilepsies, comprising three syndromes: childhood absence epilepsy, epilepsy with myoclonic absence, and epilepsy with eyelid myoclonia; and (3) developmental and/or epileptic encephalopathies, comprising five syndromes: epilepsy with myoclonic-atonic seizures, Lennox-Gastaut syndrome, developmental and/or epileptic encephalopathy with spike-and-wave activation in sleep, hemiconvulsion-hemiplegia-epilepsy syndrome, and febrile infection-related epilepsy syndrome. We define each, highlighting the mandatory seizure(s), EEG features, phenotypic variations, and findings from key investigations.

Neurobehavioral deterioration associated with sleep-augmented epileptiform abnormalities: A steroid responsive state in children

OBJECTIVE

Retrospective case record analysis of children with Neurobehavioral Deterioration associated with Sleep-augmented Epileptiform abnormalities (NDSE).

METHODS

Hospital records of children with NDSE (July, 2015 through December, 2016) were analyzed. Children were categorized as: Encephalopathy with electrical status epilepticus in sleep (ESES) if sleep EEG Spike-wave-Index (SWI) was ≥50% and sleep-induced epileptiform activity (SIEA)-related cognitive dysfunction if SWI ≥25% but <50%. Demography, neurobehavior profile (IQ/SQ and behavior using validated psychometric tools), etiology, investigations and treatment details were documented. Outcome assessment was based on three-month follow-up records.

RESULTS

Eighteen children with NDSE {12 boys; median age at diagnosis: 7.5 years (IQR: 6-10 years); SIEA (7); ESES (11)} were included. Etiology was structural (23%) and presumed genetic (77%). All children received intravenous-methylprednisolone pulse followed by oral steroids for eight weeks. Electroencephalography of children with SIEA was partly organized with median SWI of 40% (IQR 35, 42), with anterior-predominant epileptiform abnormalities and less apparent secondary synchronization. Children with ESES had a disorganized EEG background with median SWI of 80% (IQR 66, 95). Both SIEA and ESES groups had a similar neurobehavior profile. Behavior scores improved in 6/8 children with ESES and 5/7 in SIEA post steroids. In both the groups, median SWI improved (to <5% in SIEA, 45% in ESES). Mild improvement in IQ/SQ was also noted {SIEA [Median (IQR): 3 (1.6, 4.3)]; ESES [Median (IQR): 3.8 (2.8, 7)]}.

CONCLUSION

The study supports the fact that SWI >50% in the nap EEG is not mandatory for the diagnosis of ESES, thus it should not be a constraint for steroid treatment.