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.

Cenobamate in Generalized Epilepsy and Combined Generalized and Focal Epilepsy.

Background and Objectives: Cenobamate (CNB) is a United States Food and Drug Administration-approved antiseizure medication (ASM) for focal-onset seizures; however, its potential clinical effectiveness as a broad-spectrum ASM is not established. CNB has a proposed dual mechanism of action with preferential blockade of persistent sodium currents and positive allosteric modulation of the γ-aminobutyric acid-A (GABA-A) receptor. We evaluated the efficacy of CNB in drug refractory patients with genetic generalized epilepsies (GGE) or combined generalized and focal epilepsies (CGFE), including developmental and epileptic encephalopathies. Methods: We performed a retrospective review and identified the following: cohort 1 (n = 4) with GGE, of which 2 patients had idiopathic generalized epilepsy, and cohort 2 with CGFE (n = 9), of which 4 patients had Lennox-Gastaut syndrome and 1 had Dravet syndrome. Results: In cohort 1, all 3 patients with frequent generalized tonic-clonic seizures (GTCs) had a greater than 50% reduction in GTCs. In cohort 2, reduction in both generalized and focal-onset seizures was noted. In these groups together, the mean reduction of all seizure types was 58%, and ≥50% responder rate was 70% (SD = ±34.16, median = 50%). No worsening of generalized-onset seizures occurred in either cohort. Seventy-seven percent of patients experienced side effects, warranting a modification of treatment managed by slower titration, dose reduction of CNB, or discontinuing other ASMs. Discussion: In our retrospective case series, CNB seems to be an effective ASM for patients with drug-resistant GGE and CGFE. The ongoing CNB trial assessing effectiveness for primary GTCs will provide more data on generalized-onset seizures. Classification of Evidence: This study provides Class IV evidence that CNB in generalized epilepsy and combined generalized and focal epilepsy reduces seizure frequency.

Temporal Encephalocele: A Treatable Etiology of Drug-Resistant Pediatric Temporal Lobe Epilepsy.

BACKGROUND: Temporal lobe encephaloceles (TEs) are a rare cause of drug-resistant temporal lobe epilepsy (DR-TLE), with head trauma and obesity identified as risk factors in adults. This study evaluated the clinical characteristics of childhood-onset DR-TLE due to TE. METHODS: This is a single-institution retrospective review of childhood-onset DR-TLE with radiographic TE identified between 2008 and 2020. The epilepsy history, brain imaging features, and surgical outcomes were collected. RESULTS: Eleven children with DR-TLE due to TE were included (median age at epilepsy onset was 11 years, interquartile range 8.5 to 13.5 years). Median latency between epilepsy diagnosis and TE detection was 3 years (range of 0 to 13 years). None had history of head trauma. Body mass index greater than 85 percentile for age and sex was seen in 36% of the children. No patient had bilateral TE identified. TEs were diagnosed based on epilepsy surgery conference re-review of imaging in 36% of cases. All herniations were contained defects without osseous dehiscence. Regional fluorodeoxyglucose (FDG) hypometabolism ipsilateral to the encephalocele was seen in all children who had FDG-positron emission tomography (PET) of the brain. Of the children who had surgery, 70% were seizure free or had nondisabling seizures at last follow-up (mean follow-up 52 months). CONCLUSIONS: TE is a surgically remediable etiology of DR-TLE in childhood. TEs are often overlooked at pediatric epilepsy diagnosis, calling for the need to increase awareness of this entity. FDG-PET temporal hypometabolism in children with presumed nonlesional DR-TLE should be carefully examined for occult TEs.

Fenfluramine provides clinically meaningful reduction in frequency of drop seizures in patients with Lennox-Gastaut syndrome: Interim analysis of an open-label extension study.

OBJECTIVE: This study was undertaken to evaluate the long-term safety and effectiveness of fenfluramine in patients with Lennox-Gastaut syndrome (LGS). METHODS: Eligible patients with LGS who completed a 14-week phase 3 randomized clinical trial enrolled in an open-label extension (OLE; NCT03355209). All patients were initially started on .2 mg/kg/day fenfluramine and after 1 month were titrated by effectiveness and tolerability, which were assessed at 3-month intervals. The protocol-specified treatment duration was 12 months, but COVID-19-related delays resulted in 142 patients completing their final visit after 12 months. RESULTS: As of October 19, 2020, 247 patients were enrolled in the OLE. Mean age was 14.3 ± 7.6 years (79 [32%] adults) and median fenfluramine treatment duration was 364 days; 88.3% of patients received 2-4 concomitant antiseizure medications. Median percentage change in monthly drop seizure frequency was -28.6% over the entire OLE (n = 241) and -50.5% at Month 15 (n = 142, p < .0001); 75 of 241 patients (31.1%) experienced ≥50% reduction in drop seizure frequency. Median percentage change in nondrop seizure frequency was -45.9% (n = 192, p = .0038). Generalized tonic-clonic seizures (GTCS) and tonic seizures were most responsive to treatment, with median reductions over the entire OLE of 48.8% (p < .0001, n = 106) and 35.8% (p < .0001, n = 186), respectively. A total of 37.6% (95% confidence interval [CI] = 31.4%-44.1%, n = 237) of investigators and 35.2% of caregivers (95% CI = 29.1%-41.8%, n = 230) rated patients as Much Improved/Very Much Improved on the Clinical Global Impression of Improvement scale. The most frequent treatment-emergent adverse events were decreased appetite (16.2%) and fatigue (13.4%). No cases of valvular heart disease (VHD) or pulmonary arterial hypertension (PAH) were observed. SIGNIFICANCE: Patients with LGS experienced sustained reductions in drop seizure frequency on fenfluramine treatment, with a particularly robust reduction in frequency of GTCS, the key risk factor for sudden unexpected death in epilepsy. Fenfluramine was generally well tolerated; VHD or PAH was not observed long-term. Fenfluramine may provide an important long-term treatment option for LGS.

Childhood Neurologic Conditions: Epilepsy Management.

Epilepsy is the most common neurologic condition in children and is characterized by recurrent unprovoked seizures. Epilepsy can be diagnosed after a first unprovoked seizure if characteristic clinical and electroencephalographic features suggest a high risk of future seizures. Epilepsy is classified based on seizure type, underlying causes, and potential electroclinical syndromes. This classification guides management and predicts its effectiveness. Some epilepsy syndromes resolve spontaneously (ie, are self-limited) or improve with management (ie, are pharmacoresponsive). Syndromes that contribute to intellectual disability, referred to as developmental and epileptic encephalopathies, are not self-limited, are unlikely to improve with management (ie, are pharmacoresistant), and are associated with poor long-term outcomes. Antiseizure drugs are the mainstay of epilepsy management. Some broad-spectrum drugs are used to manage multiple seizure types, and others have indications for specific seizure types or epilepsy syndromes. Dietary therapy, surgical resection, and neuromodulation may be options if drugs do not control seizures. Neurodevelopmental and mental conditions are common in children with epilepsy. These include intellectual disability, learning disabilities, autism spectrum disorder, attention-deficit/hyperactivity disorder, depression, and anxiety. Patients with epilepsy should undergo screening for these associated conditions as part of routine care. Physicians should instruct caregivers and family members on how to manage seizures, including use of rescue drugs.

Efficacy and Safety of Fenfluramine for the Treatment of Seizures Associated With Lennox-Gastaut Syndrome: A Randomized Clinical Trial.

Importance: New treatment options are needed for patients with Lennox-Gastaut syndrome (LGS), a profoundly impairing, treatment-resistant, developmental and epileptic encephalopathy. Objective: To evaluate the efficacy and safety of fenfluramine in patients with LGS. Design, Setting, and Participants: This multicenter, double-blind, placebo-controlled, parallel-group randomized clinical trial was conducted from November 27, 2017, to October 25, 2019, and had a 20-week trial duration. Patients were enrolled at 65 study sites in North America, Europe, and Australia. Included patients were aged 2 to 35 years with confirmed diagnosis of LGS and experienced 2 or more drop seizures per week during the 4-week baseline. Using a modified intent-to-treat method, data analysis was performed from November 27, 2017, to October 25, 2019. The database lock date was January 30, 2020, and the date of final report was September 11, 2021. Interventions: Patients were randomized to receive either a 0.7-mg/kg/d or 0.2-mg/kg/d (maximum 26 mg/d) dose of fenfluramine or placebo. After titration (2-week period), patients were taking their randomized dose for 12 additional weeks. Main Outcomes and Measures: Primary efficacy end point was percentage change from baseline in drop seizure frequency in patients who received 0.7 mg/kg/d of fenfluramine vs placebo. Results: A total of 263 patients (median [range] age, 13 [2-35] years; 146 male patients [56%]) were randomized to the 0.7-mg/kg/d fenfluramine group (n = 87), 0.2-mg/kg/d fenfluramine group (n = 89), or placebo group (n = 87). The median percentage reduction in frequency of drop seizures was 26.5 percentage points in the 0.7-mg/kg/d fenfluramine group, 14.2 percentage points in the 0.2-mg/kg/d fenfluramine group, and 7.6 percentage points in the placebo group. The trial met its primary efficacy end point: patients in the 0.7-mg/kg/d fenfluramine group achieved a -19.9 percentage points (95% CI, -31.0 to -8.7 percentage points; P = .001) estimated median difference in drop seizures from baseline vs placebo. More patients in the 0.7-mg/kg/d fenfluramine group achieved a 50% or greater response (22 of 87 [25%]; P = .02) vs placebo (9 of 87 [10%]). Site investigators and caregivers gave a much improved or very much improved rating on the Clinical Global Impression of Improvement scale to more patients in the 0.7-mg/kg/d fenfluramine group than patients in the placebo group (21 [26%] vs 5 [6%]; P = .001). The seizure subtype that appeared most responsive to fenfluramine was generalized tonic-clonic seizure (120 of 263 [46%]), with a decrease in frequency of 45.7% in the 0.7-mg/kg/d fenfluramine group and 58.2% in the 0.2-mg/kg/d fenfluramine group compared with an increase of 3.7% in the placebo group. Most common treatment-emergent adverse events included decreased appetite (59 [22%]), somnolence (33 [13%]), and fatigue (33 [13%]). No cases of valvular heart disease or pulmonary arterial hypertension were observed. Conclusions and Relevance: Results of this trial showed that, in patients with LGS, fenfluramine compared with placebo provided a significantly greater reduction in drop seizures and may be a particularly advantageous choice in patients who experience generalized tonic-clonic seizures. Trial Registration: ClinicalTrials.gov Identifier: NCT03355209.

Safety and efficacy of responsive neurostimulation in the pediatric population: Evidence from institutional review and patient-level meta-analysis.

BACKGROUND: Responsive neurostimulation (RNS) is a novel technology for drug-resistant epilepsy rising from bilateral hemispheres or eloquent cortex. Although recently approved for adults, its safety and efficacy for pediatric patients is under investigation. METHODS: A comprehensive literature search (Pubmed/Medline, Scopus, Cochrane) was conducted for studies on RNS for pediatric epilepsy (<18 y/o) and supplemented by our institutional series (4 cases). Reduction in seizure frequency at last follow-up compared to preoperative baseline comprised the primary endpoint. RESULTS: A total of 8 studies (49 patients) were analyzed. Median age at implant was 15 years (interquartile range [IQR] 12-17) and 63% were males. A lesional MRI was noted in 64% (14/22). Prior invasive EEG recording was performed in the majority of patients (90%) and the most common modality was stereoelectroencephalography (57%). The most common implant location (total of 94 RNS leads) was the frontal lobe (27%), followed by mesial temporal structures (23%) and thalamus (17%). At a median follow-up of 22 months, median seizure frequency reduction was 75% (IQR: 50-88%) and 80% were responders (>50% seizure reduction). Responses ranged from 50% for temporal lobe epilepsy to 81-93% for frontal, parietal, and multilobar epilepsy. Four infections were observed (8%) and there were no hematomas or postoperative neurological deficits. CONCLUSION: Current evidence, albeit limited by potential publication bias, supports the promising safety and efficacy profile of RNS for medically refractory pediatric epilepsy. Randomized controlled trial data are needed to further establish the role of this intervention in preoperative discussions with patients and their families.

A tale of two cohorts: Differing outcomes in infantile-onset focal epilepsy.

OBJECTIVE: Infants with focal-onset epilepsy are an understudied population, requiring additional evaluation for clinical assessment and prognostication. Our goal was to characterize the etiology and natural history of infantile-onset focal epilepsy. METHODS: We retrospectively identified all infants (0-24 months) with onset of focal epilepsy while resident in Olmsted County, Minnesota, between 1980 and 2018, using the Rochester Epidemiology Project Database. We assessed the impact of etiology on both seizure and neurodevelopmental outcome, and mortality. RESULTS: Of 686 children with epilepsy onset <18 years, 125 (18.2%) presented with focal-onset seizures in infancy. Median follow-up for this group was 10.9 years (interquartile range [IQR] 6.2, 19.3). Etiology was identified in 65.6% (structural N = 62, genetic N = 13, both structural and genetic N = 3, metabolic N = 4). Of 107 patients followed >2 years, 38 (35.5%) developed drug-resistant epilepsy (DRE). DRE was more likely with younger age at onset, known etiology, and presence of epileptic spasms. Sixty-eight (63.0% of those with follow-up) were developmentally delayed at last follow-up, and known etiology, DRE, and presence of epileptic spasms were significantly associated with delay (p < .001 for all). Fifteen patients (12.0%) died at a median age of 7.1 years (IQR 1.7, 21.7), but only one death was seizure related (suspected sudden unexpected death in epilepsy [SUDEP]). Of 20 infants with normal development at onset and no known etiology with >2 years follow-up, none developed DRE, all were seizure-free at last follow-up (95% off antiseizure medications [ASMs]), and all remained developmentally normal. SIGNIFICANCE: Infantile-onset focal epilepsy accounts for 18% of all epilepsy in childhood, is frequently due to known etiologies, and has a high rate of DRE. However, developmentally normal infants without a known cause appear to have a very favorable course.

Comparison of Cosyntropin, Vigabatrin, and Combination Therapy in New-Onset Infantile Spasms in a Prospective Randomized Trial.

Objective: In a randomized trial, we aimed to evaluate the efficacy of cosyntropin injectable suspension, 1 mg/mL, compared to vigabatrin for infantile spasms syndrome. An additional arm was included to assess the efficacy of combination therapy (cosyntropin and vigabatrin) compared with cosyntropin monotherapy. Methods: Children (2 months to 2 years) with new-onset infantile spasms syndrome and hypsarhythmia were randomized into 3 arms: cosyntropin, vigabatrin, and cosyntropin and vigabatrin combined. Daily seizures and adverse events were recorded, and EEG was repeated at day 14 to assess for resolution of hypsarhythmia. The primary outcome measure was the composite of resolution of hypsarhythmia and absence of clinical spasms at day 14. Fisher exact test was used to compare outcomes. Results: 37 children were enrolled and 34 were included in the final efficacy analysis (1 withdrew prior to treatment and 2 did not return seizure diaries). Resolution of both hypsarhythmia and clinical spasms was achieved in in 9 of 12 participants (75%) treated with cosyntropin, 1/9 (11%) vigabatrin, and 5/13 (38%) cosyntropin and vigabatrin combined. The primary comparison of cosyntropin versus vigabatrin was significant (64% [95% confidence interval 21, 82], P < .01). Adverse events were reported in all 3 treatment arms: 31 (86%) had an adverse event, 7 (19%) had a serious adverse event, and 15 (42%) had an adverse event of special interest with no difference between treatment arms. Significance: This randomized trial was underpowered because of incomplete enrollment, yet it demonstrated that cosyntropin was more effective for short-term outcomes than vigabatrin as initial treatment for infantile spasms.

Masking for School-Age Children With Epilepsy: We Do Have Consensus!

INTRODUCTION: This study was designed to assess current recommendations from child neurologists and epileptologists on masking for school-age children with epilepsy. METHODS: A 7-item survey was created and sent out to members of the Child Neurology Society and Pediatric Epilepsy Research Consortium in August of 2021 to assess current practice and provider recommendations on masking. RESULTS: One hundred four individuals participated with representation from all regions of the United States. Masking was recommended by 95.1%, with 63.4% (n = 66) noting exception of those with severe intellectual disability, autism, and behavioral problems. Of those who write exemption letters, 54% write these <5% of the time. Only 3% reported potential adverse events associated with masking. CONCLUSION: Nearly all respondents recommended masking for school-age children with epilepsy. Potential risks of masking and adverse events were low. Improved guidance on masking is needed to ensure academic success of our patients with epilepsy.

Results of an international Delphi consensus in epilepsy with myoclonic atonic seizures/ Doose syndrome.

OBJECTIVE: To establish a standard framework for early phenotypic diagnosis, investigations, expected findings from investigations, evolution, effective therapies and prognosis in the syndrome of Epilepsy with myoclonic atonic seizures (EMAS) / Doose syndrome. METHODS: A core study group (CSG) interested in EMAS was convened. CSG then identified and nominated 15 experts in the field of EMAS. This expert panel (EP) from English speaking nations was invited to participate in anonymous questionnaires. A literature review was provided to them (supplement 1). Three rounds of questionnaires were sent to identify areas of consensus, strength of consensus and areas of contention. RESULTS: Strong consensus was obtained regarding the clinical phenotype of EMAS: myoclonic atonic seizure was identified among others as a mandatory seizure type with typical onset of afebrile seizures between one and six years. A new term "stormy phase" (SP) was designated to delineate a characteristic phenotypic evolution in EMAS patients associated with seizure worsening. Strong consensus regarding the existence and time of onset of the SP, mandatory investigations to be performed early and later in the clinical course of EMAS, first and second tier treatment and prognostic factors for poor outcome were identified. Areas of lack of consensus included some seizure types that are necessary to diagnose EMAS, interictal EEG findings that prognosticate the course of EMAS, overall duration of SP, time to complete remission, and best approach to treat drug resistant EMAS. SIGNIFICANCE: Expert consensus on core diagnostic criteria of EMAS necessary for natural history studies, phenotype-genotype correlations, and clinical trials including comparative studies was demonstrated. Areas of disagreements (especially prognostic features; treatment options) need further research.

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.

Management of Infantile Spasms During the COVID-19 Pandemic.

Circumstances of the COVID-19 pandemic have mandated a change to standard management of infantile spasms. On April 6, 2020, the Child Neurology Society issued an online statement of immediate recommendations to streamline diagnosis and treatment of infantile spasms with utilization of telemedicine, outpatient studies, and selection of first-line oral therapies as initial treatment. The rationale for the recommendations and specific guidance including follow-up assessment are provided in this manuscript. These recommendations are indicated as enduring if intended to outlast the pandemic, and limited if intended only for the pandemic health care crisis but may be applicable to future disruptions of health care delivery.

Developmental brain abnormalities and acute encephalopathy in a patient with myopathy with extrapyramidal signs secondary to pathogenic variants in MICU1.

Mitochondria play a variety of roles in the cell, far beyond their widely recognized role in ATP generation. One such role is the regulation and sequestration of calcium, which is done with the help of the mitochondrial calcium uniporter (MCU) and its regulators, MICU1 and MICU2. Genetic variations in MICU1 and MICU2 have been reported to cause myopathy, developmental disability and neurological symptoms typical of mitochondrial disorders. The symptoms of MICU1/2 deficiency have generally been attributed to calcium regulation in the metabolic and biochemical roles of mitochondria. Here, we report a female child with heterozygous MICU1 variants and multiple congenital brain malformations on MRI. Specifically, she shows anterior perisylvian polymicrogyria, dysmorphic basal ganglia, and cerebellar dysplasia in addition to white matter abnormalities. These novel findings suggest that MICU1 is necessary for proper neurodevelopment through a variety of potential mechanisms, including calcium-mediated regulation of the neuronal cytoskeleton, Miro1-MCU complex-mediated mitochondrial movement, or enhancing ATP production. This case provides new insight into the molecular pathogenesis of MCU dysfunction and may represent a novel diagnostic feature of calcium-based mitochondrial disease.

Refinement of the clinical and mutational spectrum of UBE2A deficiency syndrome.

UBE2A deficiency, that is, intellectual disability (ID) Nascimento type (MIM 300860), is an X-linked syndrome characterized by developmental delay, moderate to severe ID, seizures, dysmorphisms, skin anomalies, and urogenital malformations. Forty affected subjects have been reported thus far, with 31 cases having intragenic UBE2A variants. Here, we report on additional eight affected subjects from seven unrelated families who were found to be hemizygous for previously unreported UBE2A missense variants (p.Glu62Lys, p.Arg95Cys, p.Thr99Ala, and p.Arg135Trp) or small in-frame deletions (p.Val81_Ala83del, and p.Asp101del). A wide phenotypic spectrum was documented in these subjects, ranging from moderate ID associated with mild dysmorphisms to severe features including congenital heart defects (CHD), severe cognitive impairment, and pineal gland tumors. Four variants affected residues (Glu62, Arg95, Thr99 and Asp101) that contribute to stabilizing the structure of the E3 binding domain. The three-residue in-frame deletion, p.Val81_Ala83del, resulted from aberrant processing of the transcript. This variant and p.Arg135Trp mapped to regions of the protein located far from the E3 binding region, and caused variably accelerated protein degradation. By reviewing available clinical information, we revise the clinical and molecular profile of the disorder and document genotype-phenotype correlations. Pineal gland cysts/tumors, CHD and hypogammaglobulinemia emerge as recurrent features.