Retrospective Analysis of Presymptomatic Treatment In Sturge-Weber Syndrome.

Background: Ninety percent of infants with Sturge-Weber syndrome (SWS) brain involvement have seizure onset before 2 years of age; this is associated with worse neurologic outcome. Presymptomatic treatment before seizure onset may delay seizure onset and improve outcome, as has been shown in other conditions with a high-risk of developing epilepsy such as tuberous sclerosis complex. Electroencephalogram (EEG) may be a biomarker to predict seizure onset. This retrospective clinical data analysis aims to assess impact of presymptomatic treatment in SWS. Methods: This two-centered, IRB-approved, retrospective study analyzed records from patients with SWS brain involvement. Clinical data recorded included demographics, age of seizure onset (if present), brain involvement extent (unilateral versus bilateral), port-wine birthmark (PWB) extent, family history of seizure, presymptomatic treatment if received, neuroscore, and anti-seizure medication. EEG reports prior to seizure onset were analyzed. Results: Ninety-two patients were included (48 females), and 32 received presymptomatic treatment outside of a formal protocol (5 aspirin, 16 aspirin and levetiracetam; 9 aspirin and oxcarbazepine, 2 valproic acid). Presymptomatically-treated patients were more likely to be seizure-free at 2 years (15 of 32; 47% versus 7 of 60; 12%; p<.001). A greater percentage of presymptomatically-treated patients had bilateral brain involvement (38% treated versus 17% untreated; p=.026). Median hemiparesis neuroscore at 2 years was better in presymptomatically-treated patients. In EEG reports prior to seizure onset, the presence of slowing, epileptiform discharges, or EEG-identified seizures was associated with seizure onset by 2 (p=.001). Conclusion: Presymptomatic treatment is a promising approach to children diagnosed with SWS prior to seizure onset. Further study is needed, including prospective drug trials, long-term neuropsychological outcome, and prospective EEG analysis to assess this approach and determine biomarkers for presymptomatic treatment.

Changes in pediatric referrals after the 2009 ketogenic diet consensus recommendations.

BACKGROUND: In 2009, the International Ketogenic Diet Study Group published recommendations for children receiving ketogenic diet (KD) therapy for epilepsy. The document included a table listing epilepsy syndromes and conditions in which the KD has been particularly beneficial, hoping that physicians would refer children for the KD sooner. PURPOSE: To measure the impact of these 2009 recommendations on referral practice, we compared children initiated on the KD at Johns Hopkins Hospital (JHH) 10 years before and after the recommendations. RESULTS: Overall, children referred to the KD who met indications increased from the pre- to post-recommendation group, 44 % (112/256) to 69 % (175/255) (p < 0.001), with JHH neurologists specifically referring more frequently (10/112, 9 % to 58/175, 33 %) (p < 0.01). Referrals increased for Glut-1 deficiency (0 % to 2.4 %, p = 0.015), Dravet syndrome (0 % to 6.7 %, p < 0.01), Rett syndrome (0.4 % to 3 %, p = 0.018), and formula-fed only status (16 % to 31 %, p < 0.01). The chances of > 50 % seizure reduction for all children referred improved slightly between decades (56 % to 61 %, p = 0.30). CONCLUSIONS: Following the 2009 recommendations, our study shows there was an increase in referrals for children with indications at our center. Referrals from neurologists at our own institution increased the most. Ketogenic diet efficacy improved slightly over time but did not reach significance.

Efficacy of felbamate in a cohort of patients with epilepsy with myoclonic atonic seizures (EMAtS).

Epilepsy with myoclonic atonic seizures (EMAtS) is a rare childhood onset developmental and epileptic encephalopathy which is frequently refractory to medical therapy. The optimal antiseizure medication remains unknown. This study reports the efficacy of felbamate in children with EMAtS. Six large pediatric epilepsy centers performed a retrospective chart review on patients diagnosed with EMAtS at their institutions and collected data on felbamate usage and efficacy. Responders were classified as patients who had a 50% or greater reduction in seizures with a given therapy. Out of 259 patients, 37 (14%) were treated with felbamate. The efficacy of felbamate was 62%, which was greater than that of either levetiracetam or valproic acid (15%, p < 0.001% and 32%, p = 0.001 respectively) and similar to that of the ketogenic diet (69%, p = 0.8). Felbamate appears to be an effective treatment for EMAtS and should be strongly considered in the treatment course of this disease.

Ketogenic Diet: Parental Experiences and Expectations.

BACKGROUND: The ketogenic diet may be difficult for some patients and their families to implement and can impact physical, emotional, and social well-being. METHODS: Through principles of fundamental qualitative description, we completed an exploratory study on parents' experiences and expectations on the use and efficacy of the ketogenic diet for children with medically refractory epilepsy. RESULTS: Seventeen parents (10 mothers and 7 fathers) of 12 children with epilepsy participated. At the time of the interview, parents had experienced an average of 25 months of ketogenic diet treatment for their child (range 2 months to 98 months). Half of the caregivers learned about the ketogenic diet from their neurologist, whereas the remainder had heard about it from another source (ie, the internet). Most caregivers' (n = 13) diet expectations were related to seizure control. However, child development (n = 5) and quality of life (n = 5) were also crucial to some. Physical impacts of the diet were most commonly gastrointestinal for children (n = 9). Social and emotional effects were noted in some older children with typical development. Most caregivers described negative impacts on finances (n = 15), relationships (n = 14), and emotional well-being (ie, stress) (n = 12). Caregivers benefited from the ketogenic diet team's regular communication, close follow-up, and family-centered care. CONCLUSIONS: Despite the impacts that the ketogenic diet may have on caregivers' emotional and social well-being, the positive impacts of the diet were felt to outweigh any perceived risks. Effects (both positive and negative) on quality of life and child development (eg, social, emotional, cognitive) are essential for caregivers and require additional investigation.

The Modified Atkins Diet for Epilepsy: Two Decades of an "Alternative" Ketogenic Diet Therapy.

In 2003, the first case series of six patients treated with an Atkins diet for epilepsy was published in the journal Neurology. The concept was a simple, outpatient-initiated diet in which ketosis could be maintained by eating high-fat foods while tracking and limiting daily carbohydrate counts based on food ingredient labels. Twenty years later, after dozens of studies encompassing hundreds of patients, including several randomized controlled trials, the Modified Atkins Diet is a proven method of providing ketogenic dietary therapy for epilepsy. It is a diet therapy of choice for adolescents and adults, is being investigated for new-onset epilepsy, and is researched for neurological conditions other than epilepsy. Adverse effects do exist but may be less common than the classic ketogenic diet. This review will cover the history, clinical trials, implementation, current utilization, and future directions of this "alternative" ketogenic diet therapy on its 20-year anniversary.

Early Clinical Variables Associated With Refractory Convulsive Status Epilepticus in Children.

BACKGROUND AND OBJECTIVES: The objective of this study was to determine patient-specific factors known proximate to the presentation to emergency care associated with the development of refractory convulsive status epilepticus (RSE) in children. METHODS: An observational case-control study was conducted comparing pediatric patients (1 month-21 years) with convulsive SE whose seizures stopped after benzodiazepine (BZD) and a single second-line antiseizure medication (ASM) (responsive established status epilepticus [rESE]) with patients requiring more than a BZD and a single second-line ASM to stop their seizures (RSE). These subpopulations were obtained from the pediatric Status Epilepticus Research Group study cohort. We explored clinical variables that could be acquired early after presentation to emergency medical services with univariate analysis of the raw data. Variables with p < 0.1 were retained for univariable and multivariable regression analyses. Multivariable logistic regression models were fit to age-matched and sex-matched data to obtain variables associated with RSE. RESULTS: We compared data from a total of 595 episodes of pediatric SE. Univariate analysis demonstrated no differences in time to the first BZD (RSE 16 minutes [IQR 5-45]; rESE 18 minutes [IQR 6-44], p = 0.068). Time to second-line ASM was shorter in patients with RSE (RSE 65 minutes; rESE 70 minutes; p = 0.021). Both univariable and multivariable regression analyses revealed a family history of seizures (OR 0.37; 95% CI 0.20-0.70, p = 0.0022) or a prescription for rectal diazepam (OR 0.21; 95% CI 0.078-0.53, p = 0.0012) was associated with decreased odds of RSE. DISCUSSION: Time to initial BZD or second-line ASM was not associated with progression to RSE in our cohort of patients with rESE. A family history of seizures and a prescription for rectal diazepam were associated with a decreased likelihood of progression to RSE. Early attainment of these variables may help care for pediatric rESE in a more patient-tailored manner. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that patient and clinical factors may predict RSE in children with convulsive seizures.

Treatment Guideline Nonadherence Pretransport Associated With Need for Higher Level of Care in Children Transferred to a Pediatric Tertiary Care Center for Status Epilepticus.

OBJECTIVES: We sought to investigate the association between adherence to the American Epilepsy Society (AES) 2016 guidelines for management of convulsive status epilepticus (SE) and clinical outcomes among children requiring interhospital transport for SE. We hypothesized that pretransport guideline nonadherence would be associated with needing higher level of care posttransfer. METHODS: This was a retrospective cohort study of children aged 30 days to 18 years transferred to our pediatric tertiary center from 2017 to 2019 for management of SE. Their care episodes were classified as 2016 American Epilepsy Society guideline adherent or nonadherent. There were 40 referring hospitals represented in this cohort. RESULTS: Of 260 care episodes, 55 (21%) were guideline adherent, 184 (71%) were guideline nonadherent, and 21 (8%) had insufficient data to determine guideline adherence. Compared with the adherent group, patients in the nonadherent care group had longer hospitalizations (32 hours [17-68] vs 21 hours [7-48], P = 0.006), were more likely to require intensive care unit admission (47% vs 31%), and less likely to be discharged home from the emergency department (16% vs 35%; χ 2 test, P = 0.01). Intubation rates did not differ significantly between groups (25% vs 18%, P = 0.37). When we fit a multivariable model to adjust for confounding variables, guideline nonadherence was associated with need for higher level of care (odds ratio, 2.04; 95% confidence interval, 1.04-3.99). Treatment guideline adherence did not improve over the 3-year study period (2017: 22%, 2018: 19%, 2019: 29% [χ 2 test for differences between any 2 years, P = 0.295]). CONCLUSIONS: Guideline nonadherence pretransport was associated with longer hospitalizations and need for higher level of care among children transferred for SE at our institution. These findings suggest a need to improve SE guideline adherence through multifaceted quality improvement efforts targeting both the prehospital and community hospital settings.

Let food be thy medicine. The interaction between ketogenic diet therapy and anti-seizure medications: A systematic review.

Ketogenic diet therapy (KDT) is a nonpharmacological treatment that has been demonstrated to be effective in reducing seizures in patients with drug-resistant epilepsy. As the majority of patients on KDT are also receiving anti-seizure medications (ASMs), questions about their combination often arise. KDT is typically implemented as an add-on, and not a substitute for ASMs. Drug monitoring and specific laboratory studies may be helpful in specific cases of cotherapy. Valproate, topiramate, zonisamide, and lamotrigine may be potentially problematic with KDT, but the evidence for this is not conclusive. ASM reduction is usually attempted after 1 month of KDT if a child is showing seizure reduction (but weaning ASMs does not require seizure freedom). Failure to wean an ASM does not mean KDT has failed and adding a new ASM may be beneficial in those cases after several months of KDT fine-tuning. The purpose of this review was to discuss the evidence for possible negative (or positive) pharmacodynamic interactions between KDT and ASMs. In addition, practical suggestions for the weaning or adding of ASMs in patients on KDT are provided.

Does the ketogenic ratio matter when using ketogenic diet therapy in pediatric epilepsy?

The ketogenic diet (KD) is a widely used therapeutic option for individuals with medically refractory epilepsy. As the diet's name implies, ketosis is a historically important component of the diet, but it is not well understood how important ketosis is for seizure control. The ketogenic ratio is defined as the ratio of fat to carbohydrate plus protein by weight in the diet (grams). Traditionally, the classic KD contains a 4:1 ratio, and a very high proportion of fat in the diet. The classic KD, with its high proportion of fat and limited carbohydrate intake can be restrictive for patients with epilepsy. Recently, there is experience with use of lower ketogenic ratios and less-restrictive diets such as the modified Atkins diet and the low glycemic index treatment. In this narrative review, we examine the role of ketosis and ketogenic ratios in determining the efficacy of the KD in children with epilepsy.

Dietary Treatments for Epilepsy.

The ketogenic diet is one of the four major treatments for epilepsy, along with antiseizure medications, neuromodulation, and surgery. Ketogenic diet therapy has been proven to be a safe and effective antiseizure regimen for a century. There are multiple methods to administer the diet and the initiation should be individualized for each patient. The diet has been shown to be an effective treatment of choice for Glut1 deficiency, pyruvate dehydrogenase deficiency, infantile spasms, and superrefractory status epilepticus among others. This review discusses the administration of ketogenic diet therapy and highlights its role for specific epilepsy syndromes.

Six-month effects of modified Atkins diet implementation on indices of cardiovascular disease risk in adults with epilepsy.

BACKGROUND/AIMS: Ketogenic diet therapies (KDTs) offer a needed therapeutic option for patients with drug-resistant epilepsy. The current study investigated biochemical and anthropometric indices of cardiovascular disease (CVD) risk in adults with epilepsy treated with KDT over 6 months. METHOD: 65 adults with epilepsy naïve to diet therapy were enrolled in a prospective longitudinal study and instructed on modified Atkins diet (MAD) use. Seizure frequency, anthropometric measures, blood levels of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, apolipoproteins A1 and B, and lipoprotein sub-fractions were assessed at baseline, 3 months, and 6 months. RESULTS: Subsequent to study enrollment, 34 participants were lost to follow-up, elected not to start, or stopped MAD prior to study completion, leaving a total of 31 participants in the study at 6 months. Compared to baseline, participants on MAD showed significant reductions in median seizure frequency/week, weight, body mass index, waist and hip circumference, and percent body fat at 3 and 6 months. Compared to baseline, participants on MAD for 3 months showed significantly increased levels of total, small and medium LDL particles, ApoB and ApoB/A1 ratio. At 6 months, only small LDL particles and ApoB levels remained elevated and levels of ApoA1 had risen, suggesting possible compensatory adaptation over time. CONCLUSIONS: This study provides evidence demonstrating the efficacy and cardiovascular safety of 6 months of MAD use by adults with epilepsy. It also highlights an index of CVD risk - small LDL particles - that should be closely monitored.Trial registration: ClinicalTrials.gov identifier: NCT02694094..

Quantitative EEG improves prediction of Sturge-Weber syndrome in infants with port-wine birthmark.

OBJECTIVE: Port-wine birthmark (PWB) is a common occurrence in the newborn, and general pediatricians, dermatologists, and ophthalmologists are often called on to make an assessment of risk for Sturge-Weber syndrome (SWS) due to workforce shortages in pediatric neurologists and MRI's low sensitivity for SWS brain involvement in infants. We therefore aimed to develop a quantitative EEG (qEEG) approach to safely screen young infants with PWB for SWS risk and optimal timing of diagnostic MRI. METHODS: Forty-eight infants (prior to first birthday) underwent EEG recording. Signal processing methods compared voltage between left and right sides using a previously defined pipeline and diagnostic threshold. In this test sample, we compared sensitivity/specificity of the qEEG metric against MRI performed after the first birthday. We also used likelihood ratio testing to determine whether qEEG adds incremental information beyond topographical extent of PWB, another risk marker of brain involvement. RESULTS: qEEG helped predict SWS risk in the first year of life (p = 0.031), with a sensitivity of 50% and a specificity of 81%. It added about 40% incremental information beyond PWB extent alone (p = 0.042). CONCLUSION: qEEG adds information to risk prediction in infants with facial PWB. SIGNIFICANCE: qEEG can be used to help determine whether to obtain an MRI in the first year of life. The data collected can assist in developing a predictive model risk calculator that incorporates both PWB extent and qEEG results, which can be validated and then employed in the community.

Ketogenic Diet Therapy for Epilepsy Associated With Aicardi Syndrome.

INTRODUCTION: Aicardi syndrome is a rare neurodevelopmental disorder associated with epilepsy in females. Ketogenic diet therapy represents a possible nonpharmacologic treatment in Aicardi syndrome patients. METHODS: All patients with Aicardi syndrome seen at Johns Hopkins Hospital (Baltimore, MD) and Johns Hopkins All Children's Hospital (St Petersburg, FL) treated with ketogenic diet therapy since 1994 were evaluated retrospectively. RESULTS: Fifteen patients, ages 4 months to 34 years, were identified. Ten (67%) patients experienced a ≥50% seizure reduction after 3 months, with 3 (20%) having a ≥90% reduction. Only 1 patient was seizure-free for a short period of time. The number of drugs tried prior to ketogenic diet therapy initiation was correlated with ≥50% seizure reduction at 3 months, 5.8 vs 2.6 in responders versus nonresponders (P = .01). In addition, the mean number of drugs actively received also correlated, 3.0 vs 1.2, P = .005. Ketogenic diet therapy was slightly more successful in those without infantile spasms, 78% vs 50%, P = .33. CONCLUSION: Ketogenic diet therapy was helpful in Aicardi syndrome, although seizure freedom was rare. It was especially helpful for those who were more drug-resistant and did not have infantile spasms at ketogenic diet therapy onset.

Feasibility and Biological Activity of a Ketogenic/Intermittent-Fasting Diet in Patients With Glioma.

OBJECTIVE: To examine the feasibility, safety, systemic biological activity, and cerebral activity of a ketogenic dietary intervention in patients with glioma. METHODS: Twenty-five patients with biopsy-confirmed World Health Organization grade 2 to 4 astrocytoma with stable disease after adjuvant chemotherapy were enrolled in an 8-week Glioma Atkins-Based Diet (GLAD). GLAD consisted of 2 fasting days (calories <20% calculated estimated needs) interleaved between 5 modified Atkins diet days (net carbohydrates ≤20 g/d) each week. The primary outcome was dietary adherence by food records. Markers of systemic and cerebral activity included weekly urine ketones, serum insulin, glucose, hemoglobin A1c, insulin-like growth factor-1, and magnetic resonance spectroscopy at baseline and week 8. RESULTS: Twenty-one patients (84%) completed the study. Eighty percent of patients reached ≥40 mg/dL urine acetoacetate during the study. Forty-eight percent of patients were adherent by food record. The diet was well tolerated, with two grade 3 adverse events (neutropenia, seizure). Measures of systemic activity, including hemoglobin A1c, insulin, and fat body mass, decreased significantly, while lean body mass increased. Magnetic resonance spectroscopy demonstrated increased ketone concentrations (ß-hydroxybutyrate [bHB] and acetone) in both lesional and contralateral brain compared to baseline. Average ketonuria correlated with cerebral ketones in lesional (tumor) and contralateral brain (bHB R s = 0.52, p = 0.05). Subgroup analysis of isocitrate dehydrogenase-mutant glioma showed no differences in cerebral metabolites after controlling for ketonuria. CONCLUSION: The GLAD dietary intervention, while demanding, produced meaningful ketonuria and significant systemic and cerebral metabolic changes in participants. Ketonuria in participants correlated with cerebral ketone concentration and appears to be a better indicator of systemic activity than patient-reported food records. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov Identifier: NCT02286167.

Does the size of a ketogenic diet admission group influence outcomes?

INTRODUCTION: Most pediatric centers admit children with epilepsy for several days when initiating the ketogenic diet (KD). At some institutions, children are admitted in groups in order to save staff time and allow families to bond together for support. It is unknown if admitting children in larger groups for the KD affects outcomes. METHODS: We performed a retrospective study of all children with intractable epilepsy admitted for KD initiation at Johns Hopkins Hospital from 2010 to 2020. Charts were reviewed for size of admission groups, 3-month seizure reduction, and total KD duration. A linear mixed effects model was used to analyze KD duration between different size admission groups. RESULTS: 245 children were started on the KD, mean age 5.2 years. Thirty-three (13%) children were admitted in one-child admission groups, 52 (21%) in 2-children groups, 78 (32%) in 3-children groups, 72 (29%) in 4-children groups, and 10 (4%) in 5-children groups. At our center, fewer large admission groups and shorter KD durations have occurred over time. After adjusting for time, the 3-children admission group had higher KD duration than 1-child (1.9 times duration, p = 0.035). Additionally, after grouping cohort sizes into small (1-2 patients) versus large (3-5 patients), KD durations in the large groups were 1.6 times those in the small groups, p = 0.036. There was no statistically significant correlation between the size of the admission groups and 3-month seizure reduction. CONCLUSIONS: Admitting children in larger groups, specifically 3 children at a time, was associated with longer KD durations. This may be due to parent support from groups, listening and learning from other parents' questions, or other factors.

Diagnosing and managing childhood absence epilepsy by telemedicine.

The diagnosis of childhood absence epilepsy (CAE) is typically based on history and description of spells, supported by an office-based positive hyperventilation test and confirmed by routine electroencephalography (EEG). In the current coronavirus disease 2019 (COVID-19) pandemic, many pediatric neurologists have switched to telemedicine visits for nonemergent outpatient evaluations. We present a series of children diagnosed as having CAE on the basis of a positive hyperventilation test performed during remote televisits. Several of these children were begun on treatment for CAE prior to obtaining an EEG, with significant seizure reduction. Our series documents the feasibility of CAE diagnosis and management by telemedicine.

Sirolimus Treatment in Sturge-Weber Syndrome.

BACKGROUND: Sturge-Weber syndrome is a rare neurovascular disorder associated with capillary malformation, seizures, cognitive impairments, and stroke-like episodes (SLEs), arising from a somatic activating mutation in GNAQ. Studies suggest this mutation may cause hyperactivation of the mammalian target of rapamycin pathway. Sirolimus is an mammalian target of rapamycin inhibitor studied in other vascular anomalies and a potentially promising therapy in Sturge-Weber syndrome. METHODS: Ten patients with Sturge-Weber syndrome brain involvement and cognitive impairments were enrolled. Oral sirolimus was taken for six months (maximum dose: 2 mg/day, target trough level: 4-6 ng/mL). Neuropsychological testing, electroencephalography, and port-wine score were performed at baseline and after six months on sirolimus. Neuroquality of life, adverse events, and Sturge-Weber Syndrome Neurological Score (neuroscore) were recorded at each visit. RESULTS: Sirolimus was generally well tolerated; one subject withdrew early. Adverse events considered related to sirolimus were mostly (15/16) grade 1. A significant increase in processing speed was seen in the overall group (P = 0.031); five of nine patients with available data demonstrated statistically rare improvement in processing speed. Improvements were seen in the neuroquality of life subscales measuring anger (P = 0.011), cognitive function (P = 0.015), and depression (P = 0.046). Three subjects experiencing SLEs before and during the study reported shortened recovery times while on sirolimus. CONCLUSIONS: Sirolimus was well tolerated in individuals with Sturge-Weber syndrome and may be beneficial for cognitive impairments, especially in patients with impaired processing speed or a history of SLE. A future, randomized, placebo-controlled trial of sirolimus in patients with Sturge-Weber syndrome is needed to further understand these potentially beneficial effects.

Epilepsy with myoclonic-atonic seizures (Doose syndrome): Clarification of diagnosis and treatment options through a large retrospective multicenter cohort.

OBJECTIVE: Epilepsy with myoclonic-atonic seizures (EMAS) is a rare childhood onset epileptic encephalopathy. There is no clear consensus for recommended treatments, and pharmacoresistance is common. To better assess the clinical phenotype, most effective treatment, and determinants of cognitive and seizure outcomes, three major pediatric epilepsy centers combined data, creating the largest cohort of patients with EMAS ever studied to date. METHODS: Authors performed a retrospective chart review of patients with EMAS who received care at the authors' institutions. RESULTS: A total of 166 children were identified. Global developmental delay (>1 domain) was present in 2% of children at onset and 49% during the course of the disease. Afebrile seizures occurred after the age of 2 years in 88%, generalized tonic-clonic seizures in 60%, and drop attack or myoclonic seizures in 30%. At onset, electroencephalography (EEG) found 28% normal, background slowing in 20%, and epileptiform discharges or seizures in 69%. Subsequent EEG found slowing in 62% and discharges or seizures in 90%. Response (>50% seizure reduction) to the first three antiseizure drugs (ASDs) was 26% (levetiracetam, 17%; valproic acid, 31%; other ASDs combined, 26%). Diet therapy was used as a second or third therapy in 19% and ultimately used in 57%; response was 79%, significantly greater than the first three ASDs (P = .005, χ2 ). Seizure freedom occurred in 57% and was less likely in the case of persistent global developmental delays (P < .001), seizure recorded on subsequent EEGs (P = .027), and failure to respond to diet therapy (P = .005). Development was normal in 47%, and 12% had delays in one domain, which was less likely in the case of global developmental delay after epilepsy onset (P < .001) and failure to achieve seizure freedom (P < .001). SIGNIFICANCE: This large cohort of children with EMAS clarifies areas of variability in practice. Diet therapy is by far the most effective treatment; failure to respond was associated with failure to attain seizure freedom. This therapy should be used early in the treatment in EMAS. This study also identified a bidirectional link between cognitive and seizure outcomes.