Association of Time to Clinical Remission With Sustained Resolution in Children With New-Onset Infantile Spasms

Predictive model for initial response to first-line treatment in children with infantile epileptic spasms syndrome

BACKGROUND

Previous studies have suggested that factors such as the treatment interval and aetiology may influence the initial response rate to first-line treatment for infantile epileptic spasms syndrome (IESS). However, few children with IECSS have undergone clinically accessible tests to determine the aetiology.

METHODS

Using a dataset from our previously published research, we constructed and tested a predictive model for the initial response to first-line treatment in children with IESS. Random sampling and 5-fold cross-validation were performed, with synthetic minority oversampling technique to correct data imbalance. Machine learning algorithms and evaluation metrics optimised model accuracy and efficacy.

RESULTS

This study included 532 children with IESS who had completed monotherapy first-line treatment, of whom 160 achieved an initial response. The model's accuracy, F1 score, and area under the curve (AUC) in the validation set were 0.7836 ± 0.0229 (ranging from 0.75167 to 0.80536), 0.7833 ± 0.0229 (ranging from 0.75145 to 0.80531), and 0.8516 ± 0.0165 (ranging from 0.82468 to 0.86936), respectively. Factors such as the age of seizure onset, age of spasm onset, lead time, MRI subtype, treatment choice, and age at treatment consistently ranked in the top six for importance in contributing to the model.

CONCLUSIONS

The study findings suggest that this model may help effectively predict the initial response to first-line treatment, supporting clinical decision-making for children with IESS. Key predictors such as the age of seizure onset and MRI subtype enable early, data-driven intervention strategies in clinical practice.

Symptomatic vigabatrin-associated MRI toxicity is associated with simultaneous hormonal therapy among patients with infantile spasms

Vigabatrin-associated brain abnormalities on MRI (VABAM) are observed in approximately 20% of children who receive vigabatrin for treatment of infantile epileptic spasms syndrome. Although usually reversible and asymptomatic, VABAM is occasionally symptomatic. Whereas asymptomatic VABAM appears to be dose-dependent, symptomatic VABAM is possibly associated with co-administration of vigabatrin and hormonal therapy (i.e., corticosteroids or adrenocorticotropic hormone). With retrospective study of a cohort of vigabatrin-treated children, we evaluated candidate risk factors for VABAM. Among 108 children with detailed vigabatrin exposure data, we identified VABAM in 17 children (11 symptomatic). Symptomatic VABAM was strongly associated with simultaneous exposure to hormonal therapy (p = 0.001). Neither symptomatic nor asymptomatic VABAM were associated with peak vigabatrin dose. Although these data support the hypothesis that symptomatic VABAM risk is higher with coadministration of vigabatrin and hormonal therapy, this study does not establish a causal link. Further study is warranted to better understand the pathogenesis of VABAM and devise strategies to mitigate risk. Clinicians should carefully weigh the potential risk of symptomatic vigabatrin toxicity against the known benefit of vigabatrin and hormonal therapy coadministration. PLAIN LANGUAGE SUMMARY: Several case reports suggest that the combination of vigabatrin and hormonal therapy for treatment of infantile spasms may provoke an adverse reaction known as symptomatic vigabatrin MRI toxicity (sVABAM, which includes characteristic changes on MRI images and associated symptoms). In response to these reports, we studied a large single-center cohort of children with infantile spasms and determined that combination therapy is indeed statistically associated with sVABAM. However, we have not proven that combination therapy actually causes sVABAM. Further study is needed to clarify the nature of sVABAM and risk factors thereof.

Outcomes following resective and disconnective strategies in the treatment of epileptic spasms: a systematic review of the literature and individual patient data meta-analysis

Epileptic spasms (ES) are a unique seizure type typically presenting in the form of infantile epileptic spasms syndrome (IESS) with characteristic hypsarrhythmia on scalp EEG and a preponderance with developmental delay or regression. While pharmacotherapy is the mainstay of treatment, surgical options, including disconnective or resective procedures, are increasingly recognized as viable therapeutic options for recurrent or persistent ES. However, limited data on safety, effectiveness, and prognostic factors hinder informed decision-making regarding surgery indications, timing, and intervention type. We performed a systematic review and an individual patient data meta-analysis (IPDMA) in accordance with PRISMA guidelines, focusing on surgical interventions for ES and reporting seizure outcomes using the Engel or ILAE scales. Twenty-six studies encompassing 358 ES patients undergoing resection/callosotomy were included. Participants undergoing other approaches (e.g., multiple subpial transections) or multimodality approaches were excluded from analysis. The median age at spasm onset was 6 months (IQR = 3.0-15.6), with a median age at surgery of 37 months (IQR = 17.2-76.8). Most patients (74.1%) exhibited additional seizure types. A total of 136 patients (35.8%) underwent corpus callosotomy (CC), of whom 125 (91.9%) had a complete callosotomy, while 11 (8.1%) had a partial callosotomy. Resective surgery was performed on 222 patients (58.4%). Among those who underwent resection, 109 (49.1%) had both lesional MRI findings and lateralized EEG abnormalities. Overall, 201 patients (56.1%) remained spasm-free at a median postoperative follow-up of 36 months (interquartile range, IQR = 21-60), including 52 (38.2%) from the callosotomy group and 149 (67.1%) from the resective surgery group. In the resective surgery cohort, patients with MRI-confirmed lesions (p = 0.026; HR = 0.53, 95% CI = 0.31-0.93) and those who underwent hemispherectomy (p = 0.026, HR = 0.46, 95% CI = 0.23-0.91) had better seizure outcomes. Only a minority (24.4%) underwent invasive EEG monitoring prior to ES surgery. Surgical treatment of ES proves effective, with two thirds of patients undergoing resective surgery and a third undergoing CC becoming spasm free. Post-operative developmental improvement was observed in 44 participants (65.7% of those with available data). The presence of lesional MRI and more extensive resection/disconnection (e.g., hemispherectomy) emerged as significant prognostic factors for spasm freedom and can inform clinical decision-making.

Characteristics of overnight video-EEG monitoring in infantile epileptic spasms syndrome at 2-week follow-up

OBJECTIVE

To determine the optimal duration of electroencephalography (EEG) recording to detect epileptic spasms (ES) based on inpatient overnight video-EEG monitoring in patients with infantile epileptic spasms syndrome (IESS) at the 2-week follow-up.

METHODS

Patients with IESS and overnight EEG monitoring between January 2020 and June 2022 were retrospectively reviewed. Time-to-ES, time-to-sleep and time-to-epileptic encephalopathy (EE) per the Burden of Amplitudes and Epileptiform Discharges (BASED 2021) score. BASED 2021 score were reported. ES and sleep detection sensitivity were calculated with respect to monitoring time. Etiology, treatment, and EEG features were assessed for strength of association with continued ES. Time-to-event analysis was performed with the first ES as the event of interest.

RESULTS

Of 90 patients, 39 (43%) continued to have ES; 78.6% with EE continued to have ES, whereas only 27.4% without EE had ES (odds ratio [OR] 12.05). Structural etiologies were also associated with continued ES (OR 5.24). ES detection was 35.9%, 76.9%, and 84.6% at 1, 4, and 6 h, respectively, with corresponding negative likelihood ratios (NLRs) of .64, .23, and .15. ES detection reached >90% and >95% at 14 and 19 h, respectively. Sleep detection was 52.2%, 84.4%, and 95.6% at 1, 4, and 6 h, respectively, and captured in all patients by 11 h. EE was observed by 6 h for all associated patients.

SIGNIFICANCE

Typical routine EEG durations (<1 h) were not sufficient to detect ES, EE, or sleep in patients with IESS at the 2-week follow-up. Four hour outpatient EEG will capture ES in 77% and sleep in 84% of the patients. EE, if present, was shortly after sleep onset. Additional monitoring of up to 19 h was needed to capture >95% of patients with ES. Although EE was strongly associated with continued ES, 27.4% of patients without EE demonstrated ES. This study will help guide adequate duration of EEG monitoring at the 2-week follow-up for patients with IESS.

Optimization of vigabatrin dosage in children with epileptic spasms: A population pharmacokinetic approach

AIMS

Vigabatrin is an antiepileptic drug used to treat some forms of severe epilepsy in children. The main adverse effect is ocular toxicity, which is related to the cumulative dose. The aim of the study is to identify an acceptable exposure range, both through the development of a population pharmacokinetic model of vigabatrin in children enabling us to calculate patient exposure and through the study of therapeutic response.

METHODS

We performed a retrospective study including children with epilepsy followed at Necker-Enfants Malades hospital who had a vigabatrin assay between January 2019 and January 2022. The population pharmacokinetic study was performed on Monolix2021 using a nonlinear mixed-effects modelling approach. Children treated for epileptic spasms were classified into responder and nonresponder groups according to whether the spasms resolved, in order to identify an effective plasma exposure range.

RESULTS

We included 79 patients and analysed 159 samples. The median age was 4.2 years (range 0.3-18). A 2-compartment model with allometry and creatinine clearance on clearance best fit our data. Exposure analysis was performed on 61 patients with epileptic spasms. Of the 22 patients who responded (36%), 95% had an AUC0-24 between 264 and 549 mg.h.L-1.

CONCLUSIONS

The population pharmacokinetic model allowed us to identify bodyweight and creatinine clearance as the 2 main factors explaining the observed interindividual variability of vigabatrin. An acceptable exposure range was defined in this study. A target concentration intervention approach using this pharmacokinetic model could be used to avoid overexposure in responder patients.

Exhaustive clinical examination of etiology and initial response to first-line treatment in 577 children with infantile epileptic spasm syndrome children: A 5-year retrospective observational study

OBJECTIVE

Employing whole-exome sequencing (WES) technology to investigate the etiology of infantile epileptic spasm syndrome (IESS), and determining whether different etiologies exhibit phenotypic variations, while elucidating the potential associated factors, might improve short-term responses to first-line treatment.

METHODS

We retrospectively evaluated patients with IESS admitted for treatment between January 2018 and June 2023. Clinical phenotypic differences among etiological classifications and clinical manifestations were analyzed. Variable selection using the best subset method was performed, followed by logistic regression analysis to identify the factors influencing treatment response.

RESULTS

A total of 577 patients were included; 412 completed trio-WES. Magnetic resonance imaging abnormalities were detected in 387 patients (67.1%). Patients with etiology as structural abnormalities were likelier to have non-spasms at the initial seizure onset. A total of 532 patients completed the first-line treatment; 273 patients received it for the first time at our hospital (initial response rates: 30.1% and 42.1%, respectively). The response group had a lower proportion of early-onset seizures (≤3 months) than the no-response group (11.3% vs. 23.7%, p < 0.01 and 11.3% vs. 21.5%, p = 0.03, respectively). Logistic regression analysis indicated that earlier initiation of first-line treatment was associated with a higher likelihood of an initial response. However, the etiological classification did not have a significant impact on the initial response.

INTERPRETATION

IESS patients with structural abnormalities are more likely to present with non-spasm seizures at initial onset. Early initiation of first-line treatment is crucial; however, initial responses may be less favorable when seizures occur in early infancy.

Effective treatment of NR2F1-related epilepsy with perampanel

BACKGROUND

NR2F1 mutations are associated with Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS). Although ~ 46.7% of BBSOAS patients present with epilepsy, which is always drug-resistant and associated with higher rates of behavioral and cognitive problems, the treatment and outcomes of NR2F1-related epilepsy have rarely been described. Here, we present new cases of BBSOAS-related epilepsy and summarize all previously reported cases to explore the effective treatment for this type of epilepsy.

METHODS

We identified six new Chinese cases of BBSOAS with epilepsy. Five different de novo heterozygous NR2F1 mutations were identified in these cases, including two novel mutations c.365G > T, p.Cys122Phe and c.449G > T, p.Gly150Val. By combining the six cases and 14 previously reported cases, we analyzed the characteristics and treatment outcomes of NR2F1-related epilepsy.

RESULTS

Twelve of the 20 patients (60%) had infantile epileptic spasms, while the other patients had generalized tonic/tonic-clonic, focal, myoclonic, absence, or unclassified seizures. Several anti-seizure medications, steroids, and a ketogenic diet were administered in these cases. However, seizures were controlled in only 50% of previously reported cases, while all of the six new cases became seizure-free after perampanel as an add-on treatment. The average time from the addition of perampanel to seizure control was 7.33 ± 4.59 months (range, 1-12 months). The median time to seizure freedom was 14 months (1-32 months, > 19 months in 3 cases). The average dosage of perampanel needed for epilepsy control was 0.22 ± 0.17 mg/kg per day.

CONCLUSIONS

In this paper, we comprehensively summarized the clinical characteristics, treatments and outcomes of NR2F1-related epilepsy for the first time. Perampanel exhibits dramatic efficacy for NR2F1-related epilepsy. This will help optimize the treatment of this type of epilepsy and provide clues for its pathogenic mechanisms. The two novel mutations expand the genotype spectrum of this disease.

Epilepsy and Encephalopathy

BACKGROUND

Epilepsy encompasses more than the predisposition to unprovoked seizures. In children, epileptic activity during (ictal) and between (interictal) seizures has the potential to disrupt normal brain development. The term "epileptic encephalopathy (EE)" refers to the concept that such abnormal activity may contribute to cognitive and behavioral impairments beyond that expected from the underlying cause of the epileptic activity.

METHODS

In this review, we survey the concept of EE across a diverse selection of syndromes to illustrate its broad applicability in pediatric epilepsy. We review experimental evidence that provides mechanistic insights into how epileptic activity has the potential to impact normal brain processes and the development of neural networks. We then discuss opportunities to improve developmental outcomes in epilepsy now and in the future.

RESULTS

Epileptic activity in the brain poses a threat to normal physiology and brain development.

CONCLUSION

Until we have treatments that reliably target and effectively treat the underlying causes of epilepsy, a major goal of management is to prevent epileptic activity from worsening developmental outcomes.

Efficacy of vigabatrin in the treatment of infantile epileptic spasms syndrome: A systematic review and meta-analysis

This systematic review and meta-analysis aimed to evaluate the efficacy of vigabatrin (VGB) in treating infantile epileptic spasms syndrome (IESS). Databases of PubMed, Embase, Web of Science, MEDLINE, and Cochrane Library were systematically searched. All the relevant randomized controlled trials (RCTs) and observational studies (OSs) of VGB for IESS were included and analyzed separately. The primary outcome was the cessation of epileptic spasms (ES). Five RCTs and nine OSs compared the efficacy of VGB vs hormonal monotherapy for IESS. Meta-analysis of the five RCTs showed that hormonal monotherapy was significantly better than VGB monotherapy (OR = 0.37, 95% CI = 0.20-0.67) for patients with new-onset IESS. Meta-analysis of the nine OSs agrees with the result from RCTs (OR = 0.61, 95% CI = 0.43-0.85). VGB was more effective in patients with TSC than in those with other etiologies (five OSs, OR = 5.59, 95% CI = 2.17-14.41). There was no significant difference in the efficiency of VGB combined with hormonal therapy vs hormonal monotherapy for IESS (two RCTs, OR = 0.75, 95% CI = 0.09-6.45). Hormonal monotherapy is better than VGB monotherapy for non-TSC-associated IESS. But for patients with IESS due to TSC, VGB is the first choice. VGB combined with hormone therapy does not definitely increase ES control rates compared with that of hormonal monotherapy.