Gain of function SCN1A disease-causing variants: Expanding the phenotypic spectrum and functional studies guiding the choice of effective antiseizure medication.

OBJECTIVE: This study was undertaken to refine the spectrum of SCN1A epileptic disorders other than Dravet syndrome (DS) and genetic epilepsy with febrile seizures plus (GEFS+) and optimize antiseizure management by correlating phenotype-genotype relationship and functional consequences of SCN1A variants in a cohort of patients. METHODS: Sixteen probands carrying SCN1A pathogenic variants were ascertained via a national collaborative network. We also performed a literature review including individuals with SCN1A variants causing non-DS and non-GEFS+ phenotypes and compared the features of the two cohorts. Whole cell patch clamp experiments were performed for three representative SCN1A pathogenic variants. RESULTS: Nine of the 16 probands (56%) had de novo pathogenic variants causing developmental and epileptic encephalopathy (DEE) with seizure onset at a median age of 2 months and severe intellectual disability. Seven of the 16 probands (54%), five with inherited and two with de novo variants, manifested focal epilepsies with mild or no intellectual disability. Sodium channel blockers never worsened seizures, and 50% of patients experienced long periods of seizure freedom. We found 13 SCN1A missense variants; eight of them were novel and never reported. Functional studies of three representative variants showed a gain of channel function. The literature review led to the identification of 44 individuals with SCN1A variants and non-DS, non-GEFS+ phenotypes. The comparison with our cohort highlighted that DEE phenotypes are a common feature. SIGNIFICANCE: The boundaries of SCN1A disorders are wide and still expanding. In our cohort, >50% of patients manifested focal epilepsies, which are thus a frequent feature of SCN1A pathogenic variants beyond DS and GEFS+. SCN1A testing should therefore be included in the diagnostic workup of pediatric, familial and nonfamilial, focal epilepsies. Alternatively, non-DS/non-GEFS+ phenotypes might be associated with gain of channel function, and sodium channel blockers could control seizures by counteracting excessive channel function. Functional analysis evaluating the consequences of pathogenic SCN1A variants is thus relevant to tailor the appropriate antiseizure medication.

Long-term effectiveness of add-on perampanel in patients with Lennox-Gastaut syndrome: A multicenter retrospective study.

This retrospective study assessed long-term effectiveness of add-on perampanel (PER) in patients with Lennox-Gastaut syndrome (LGS). Outcomes included time to PER failure and time to seizure relapse in responders. PER failure was defined as either discontinuation of PER or initiation of another treatment. Seizure relapse in responders was defined as occurrence of a seizure in seizure-free patients and increase of at least 50% in average monthly seizure frequency for those who were responders. Eighty-seven patients were included. Treatment failure occurred in 52 (59.8%) subjects at a median time of 12 months. Treatment failure was due to lack of efficacy in 27 (52.0%) patients, lack of tolerability in 14 (27.0%), and both reasons in 11 (21.0%). A slower titration was associated with a lower risk of PER failure compared to faster titration schedules, and the occurrence of adverse events increased the risk of treatment failure. Thirty-six patients (41.4%) were responders during a median follow-up of 11 months. Seizure relapse occurred in 13 of 36 (36.1%) patients after a median time of 21 months. The overall rate of seizure responders was 23 of 87 (26.4%) at the end of follow-up. This study provides real-world evidence on the effectiveness of PER as adjunctive treatment in LGS patients.

Epilepsy, electroclinical features, and long-term outcomes in Pitt-Hopkins syndrome due to pathogenic variants in the TCF4 gene.

BACKGROUND AND PURPOSE: Pitt-Hopkins syndrome (PTHS) is a rare neurodevelopmental disorder caused by deletions/variants in the TCF4 gene. Seizures may be present in up to half of the patients, leading to a more severe disease burden. This study aims to analyse the electroclinical phenotype, treatment options, and long-term outcomes of epilepsy in PTHS. METHODS: A multicentre observational cohort study was performed, and the electroclinical data of PTHS individuals affected by epileptic seizures were retrospectively reviewed and analysed. RESULTS: The series includes 21 patients (11 female) with a median age at seizure onset of 2 years (range = 0.5-8). The median time of follow-up was 7.9 years (range = 2-27). Both generalized and focal epilepsies were present at the same prevalence (42.8%), whereas a minority of patients presented developmental and epileptic encephalopathies (14.4%). At the long-term follow-up, 42.8% achieved seizure freedom, whereas 42.8% developed drug-resistant epilepsy (DRE). The age at seizure onset was found to be an independent predictor for seizure outcome; in this regard, patients having seizure onset after the age of 2 years were more prone to achieve seizure freedom (odds ratio = 0.04, 95% confidence interval = 0.003-0.53; p = 0.01). During evolution, seizures tended to settle down, and even in patients with DRE, seizures tended to persist at a lower frequency and appeared to be more easily manageable over time. CONCLUSIONS: This study provides new insight into the natural history of epilepsy in PTHS. Better characterization of epileptic phenotype and prompt tailored treatment improve overall management and quality of life.

Temporal lobe epilepsy surgery in children and adults: A multicenter study.

OBJECTIVE: To assess seizure and cognitive outcomes and their predictors in children (<16 years at surgery) and adults undergoing temporal lobe epilepsy (TLE) surgery in eight Italian centers. METHODS: This is a retrospective multicenter study. We performed a descriptive analysis and subsequently carried out multivariable mixed-effect models corrected for multiple comparisons. RESULTS: We analyzed data from 511 patients (114 children) and observed significant differences in several clinical features between adults and children. The possibility of achieving Engel class IA outcome and discontinuing antiepileptic drugs (AEDs) at last follow-up (FU) was significantly higher in children (P = .006 and < .0001). However, percentages of children and adults in Engel class I at last FU (mean ± SD, 45.9 ± 17 months in children; 45.9 ± 20.6 months in adults) did not differ significantly. We identified different predictors of seizure outcome in children vs adults and at short- vs long-term FU. The only variables consistently associated with class I outcome over time were postoperative electroencephalography (EEG) in adults (abnormal, improved,odds ratio [OR] = 0.414, P = .023, Q = 0.046 vs normal, at 2-year FU and abnormal, improved, OR = 0.301, P = .001, Q = 0.002 vs normal, at last FU) and the completeness of resection of temporal magnetic resonance (MR) abnormalities other than hippocampal sclerosis in children (OR = 7.93, P = .001, Q = 0.003, at 2-year FU and OR = 45.03, P < .0001, Q < 0.0001, at last FU). Cognitive outcome was best predicted by preoperative performances in either age group. SIGNIFICANCE: Clinical differences between adult and pediatric patients undergoing TLE surgery are reflected in differences in long-term outcomes and predictors of failures. Children are more likely to achieve sustained seizure freedom and withdraw AEDs after TLE surgery. Earlier referral should be encouraged as it can improve surgical outcome.

Perampanel effectiveness and tolerability in patients with epilepsy at long-term follow-up.

INTRODUCTION: The main of the present study was to assess the effectiveness and tolerability of perampanel (PER) in association with 1 or 2 concomitant antiseizure medications (ASMs) in patients with epilepsy throughout a follow-up period of 24 months or longer in a real-world setting. METHODS: This retrospective, observational, multi-center study collected data from both underage (<18 years old) and adult patients who had started PER in association with 1 or 2 ASMs. Only patients who had started PER and were followed up for at least 24 months were included. Response to treatment was analyzed at the 24-, 36-, and 48-month visits by considering the last visit undergone by patients. Subgroup analyses were performed according to age, gender, and epilepsy type and patients were categorized following PER treatment in concomitance with 1 or 2 ASMs to evaluate the factors affecting the achievement of seizure freedom (SF) at the 24-month FU. RESULTS: Ninety-four patients were included (mean age 36.89 years; 51.1% female). At the 24-month follow-up visit, 90 (95.74%) patients were still receiving PER concomitantly with 1 or 2 ASMs. The mean PER dose was 6.02 mg/day and SF was achieved by 33 (35.1%) patients. A significantly higher SF rate was found in patients who had started PER with only 1 ASM when compared to those who had started PER with 2 concomitant ASMs. Effectiveness was maintained also in the subgroups of patients with a 36- or 48-month follow-up visit. Adult patients had a higher final daily dosage of PER than underage patients. Logistic regression found that the lowest number of previously failed ASMs was associated with a higher SF rate (p = 0.036). CONCLUSION: Perampanel demonstrated a good effectiveness in association with 1 or 2 ASMs in both pediatric and adult patients, without having to use a high dose of the drug. The possibility to present SF was higher when PER was added early. Finally, the maintenance of effectiveness was observed also in the subgroups of patients with a follow-up of 36 and 48 months.

Trends in pediatric epilepsy surgery in Europe between 2008 and 2015: Country-, center-, and age-specific variation.

OBJECTIVE: To profile European trends in pediatric epilepsy surgery (<16 years of age) between 2008 and 2015. METHODS: We collected information on volumes and types of surgery, pathology, and seizure outcome from 20 recognized epilepsy surgery reference centers in 10 European countries. RESULTS: We analyzed retrospective aggregate data on 1859 operations. The proportion of surgeries significantly increased over time (P < .0001). Engel class I outcome was achieved in 69.3% of children, with no significant improvement between 2008 and 2015. The proportion of histopathological findings consistent with glial scars significantly increased between the ages of 7 and 16 years (P for trend = .0033), whereas that of the remaining pathologies did not vary across ages. A significant increase in unilobar extratemporal surgeries (P for trend = .0047) and a significant decrease in unilobar temporal surgeries (P for trend = .0030) were observed between 2008 and 2015. Conversely, the proportion of multilobar surgeries and unrevealing magnetic resonance imaging cases remained unchanged. Invasive investigations significantly increased, especially stereo-electroencephalography. We found different trends comparing centers starting their activity in the 1990s to those whose programs were developed in the past decade. Multivariate analysis revealed a significant variability of the proportion of the different pathologies and surgical approaches across countries, centers, and age groups between 2008 and 2015. SIGNIFICANCE: Between 2008 and 2015, we observed a significant increase in the volume of pediatric epilepsy surgeries, stability in the proportion of Engel class I outcomes, and a modest increment in complexity of the procedures.

Defining the electroclinical phenotype and outcome of PCDH19-related epilepsy: A multicenter study.

OBJECTIVE: PCDH19-related epilepsy is an epileptic syndrome with infantile onset, characterized by clustered and fever-induced seizures, often associated with intellectual disability (ID) and autistic features. The aim of this study was to analyze a large cohort of patients with PCDH19-related epilepsy and better define the epileptic phenotype, genotype-phenotype correlations, and related outcome-predicting factors. METHODS: We retrospectively collected genetic, clinical, and electroencephalogram (EEG) data of 61 patients with PCDH19-related epilepsy followed at 15 epilepsy centers. All consecutively performed EEGs were analyzed, totaling 551. We considered as outcome measures the development of ID, autistic spectrum disorder (ASD), and seizure persistence. The analyzed variables were the following: gender, age at onset, age at study, genetic variant, fever sensitivity, seizure type, cluster occurrence, status epilepticus, EEG abnormalities, and cognitive and behavioral disorders. Receiver operating characteristic curve analysis was performed to evaluate the age at which seizures might decrease in frequency. RESULTS: At last follow-up (median = 12 years, range = 1.9-42.1 years), 48 patients (78.7%) had annual seizures/clusters, 13 patients (21.3%) had monthly to weekly seizures, and 12 patients (19.7%) were seizure-free for ≥2 years. Receiver operating characteristic analysis showed a significant decrease of seizure frequency after the age of 10.5 years (sensitivity = 81.0%, specificity = 70.0%). Thirty-six patients (59.0%) had ID and behavioral disturbances. ASD was present in 31 patients. An earlier age at epilepsy onset emerged as the only predictive factor for ID (P = 0.047) and ASD (P = 0.014). Conversely, age at onset was not a predictive factor for seizure outcome (P = 0.124). SIGNIFICANCE: We found that earlier age at epilepsy onset is related to a significant risk for ID and ASD. Furthermore, long-term follow-up showed that after the age of 10 years, seizures decrease in frequency and cognitive and behavioral disturbances remain the primary clinical problems.

Increasing volume and complexity of pediatric epilepsy surgery with stable seizure outcome between 2008 and 2014: A nationwide multicenter study.

OBJECTIVE: The objective of the study was to assess common practice in pediatric epilepsy surgery in Italy between 2008 and 2014. METHODS: A survey was conducted among nine Italian epilepsy surgery centers to collect information on presurgical and postsurgical evaluation protocols, volumes and types of surgical interventions, and etiologies and seizure outcomes in pediatric epilepsy surgery between 2008 and 2014. RESULTS: Retrospective data on 527 surgical procedures were collected. The most frequent surgical approaches were temporal lobe resections and disconnections (133, 25.2%) and extratemporal lesionectomies (128, 24.3%); the most frequent etiologies were FCD II (107, 20.3%) and glioneuronal tumors (105, 19.9%). Volumes of surgeries increased over time independently from the age at surgery and the epilepsy surgery center. Engel class I was achieved in 73.6% of patients (range: 54.8 to 91.7%), with no significant changes between 2008 and 2014. Univariate analyses showed a decrease in the proportion of temporal resections and tumors and an increase in the proportion of FCDII, while multivariate analyses revealed an increase in the proportion of extratemporal surgeries over time. A higher proportion of temporal surgeries and tumors and a lower proportion of extratemporal and multilobar surgeries and of FCD were observed in low (<50surgeries/year) versus high-volume centers. There was a high variability across centers concerning pre- and postsurgical evaluation protocols, depending on local expertise and facilities. SIGNIFICANCE: This survey reveals an increase in volume and complexity of pediatric epilepsy surgery in Italy between 2008 and 2014, associated with a stable seizure outcome.

Symptomatic and presumed symptomatic focal epilepsies in childhood: An observational, prospective multicentre study.

OBJECTIVE: To describe the clinical, neuropsychological, and psychopathologic features of a cohort of children with a new diagnosis of symptomatic or presumed symptomatic focal epilepsy at time of recruitment and through the first month. The selected population will be followed for 2-5 years after enrollment to investigate the epilepsy course and identify early predictors of drug resistance. METHODS: In this observational, multicenter, nationwide study, children (age 1 month-12.9 years) with a new diagnosis of symptomatic or presumed symptomatic focal epilepsy were consecutively enrolled in 15 Italian tertiary childhood epilepsy centers. Inclusion criteria were as follows: (1) diagnosis of symptomatic focal epilepsy due to acquired and developmental etiologies, and presumed symptomatic focal epilepsy; (2) age at diagnosis older than 1 month and <13 years; and (3) written informed consent. Children were subdivided into three groups: ≤3 years, >3 to 6 years, and >6 years. Clinical, electroencephalography (EEG), neuroimaging, and neuropsychological variables were identified for statistical analyses. RESULTS: Two hundred fifty-nine children were enrolled (116 female and 143 male). Median age: 4.4 years (range 1 month-12.9 years); 46.0% (n = 119) of children were younger than 3 years, 24% (61) from 3 to 6 years of age, and 30% (79) older than 6 years. Neurologic examination findings were normal in 71.8%. Brain magnetic resonance imaging (MRI) was abnormal in 59.9%. Children age ≤3 years experienced the highest seizure frequency in the first month after recruitment (p < 0.0001). Monotherapy in the first month was used in 67.2%. Cognitive tests at baseline revealed abnormal scores in 30%; behavioral problems were present in 21%. At multivariate analysis, higher chances to exhibit more than five seizures in the first month after epilepsy onset was confirmed for younger children and those with temporal lobe epilepsy. SIGNIFICANCE: In this prospective cohort study, an extensive characterization of epilepsy onset in children with symptomatic or presumed symptomatic focal epilepsies is reported in relation to the age group and the localization of the epileptogenic zone.

An educational campaign about epilepsy among Italian primary school teachers. 2. The results of a focused training program.

A cohort of 582 Italian primary school teachers underwent a questionnaire survey to test their knowledge and attitudes toward epilepsy and verify whether an intensive and focused educational program could result in improvement of knowledge and attitudes. The program consisted of a presentation of the clinical manifestations of epilepsy and the distribution of informative brochures and an educational kit on the disease and its management to be used with their students. After several months, 317 teachers were retested using the same questions. Upon retest, the number of "don't know" answers decreased significantly for almost all questions. This was not the case for negative attitudes. The same holds true for teachers believing that epilepsy is a source of learning disability and social disadvantage. These findings support the beliefs that education on epilepsy is more likely to affect ignorance than prejudice and that stronger interventions are needed to counteract stigmatizing behaviors.

Long-term seizure and behavioral outcomes after corpus callosotomy.

Outcomes of corpus callosotomy (CC) have been mainly focused on seizures. The present study aimed to evaluate the long-term effects of CC on adaptive behaviors and caregivers' satisfaction in addition to seizures and to identify clinical predictors of postsurgical outcomes. Medical records of 26 patients (mean age at study time: 40 years, mean follow-up: 14 years) with childhood-onset epilepsy who underwent anterior or 2-stage complete CC were reviewed. A structured questionnaire was submitted to caregivers asking about relative changes in different seizure types, behavioral functions, and satisfaction with the postoperative outcomes. Formal neuropsychological assessment was carried out in a subgroup of patients. Selected clinical variables including age at surgery, extent of callosal section, length of follow-up, epilepsy syndrome, and presurgical cognitive level were submitted to multiple regression analysis. At the last follow-up visit, a reduction greater than 50% was observed mainly for drop attacks (65% of patients), followed by generalized tonic-clonic seizures (53%), and complex partial seizures (50%). No presurgical variables were significantly associated with seizure outcome. After surgery, more than half of patients showed attention enhancement, which was related to drop seizure improvement. Early age at surgery was associated with better behavioral regulation; complete CC slightly worsened language abilities. Satisfaction with surgery outcomes was expressed by 73% of caregivers and was dependent on drop seizure reduction and improvements in activities of daily living. A long-term positive psychosocial outcome is likely after CC also in severely disabled patients, especially if surgery is performed early.

Biochemical, structural, and computational analyses of two new clinically identified missense mutations of ALDH7A1.

Aldehyde dehydrogenase 7A1 (ALDH7A1) catalyzes a step of lysine catabolism. Certain missense mutations in the ALDH7A1 gene cause pyridoxine dependent epilepsy (PDE), a rare autosomal neurometabolic disorder with recessive inheritance that affects almost 1:65,000 live births and is classically characterized by recurrent seizures from the neonatal period. We report a biochemical, structural, and computational study of two novel ALDH7A1 missense mutations that were identified in a child with rare recurrent seizures from the third month of life. The mutations affect two residues in the oligomer interfaces of ALDH7A1, Arg134 and Arg441 (Arg162 and Arg469 in the HGVS nomenclature). The corresponding enzyme variants R134S and R441C (p.Arg162Ser and p.Arg469Cys in the HGVS nomenclature) were expressed in Escherichia coli and purified. R134S and R441C have 10,000- and 50-fold lower catalytic efficiency than wild-type ALDH7A1, respectively. Sedimentation velocity analytical ultracentrifugation shows that R134S is defective in tetramerization, remaining locked in a dimeric state even in the presence of the tetramer-inducing coenzyme NAD+. Because the tetramer is the active form of ALDH7A1, the defect in oligomerization explains the very low catalytic activity of R134S. In contrast, R441C exhibits wild-type oligomerization behavior, and the 2.0 Å resolution crystal structure of R441C complexed with NAD+ revealed no obvious structural perturbations when compared to the wild-type enzyme structure. Molecular dynamics simulations suggest that the mutation of Arg441 to Cys may increase intersubunit ion pairs and alter the dynamics of the active site gate. Our biochemical, structural, and computational data on two novel clinical variants of ALDH7A1 add to the complexity of the molecular determinants underlying pyridoxine dependent epilepsy.

Molecular and Phenotypic Characterization of the RORB-Related Disorder.

BACKGROUND AND OBJECTIVES: Heterozygous variants in RAR-related orphan receptor B (RORB) have recently been associated with susceptibility to idiopathic generalized epilepsy. However, few reports have been published so far describing pathogenic variants of this gene in patients with epilepsy and intellectual disability (ID). In this study, we aimed to delineate the epilepsy phenotype associated with RORB pathogenic variants and to provide arguments in favor of the pathogenicity of variants. METHODS: Through an international collaboration, we analyzed seizure characteristics, EEG data, and genotypes of a cohort of patients with heterozygous variants in RORB. To gain insight into disease mechanisms, we performed ex vivo cortical electroporation in mouse embryos of 5 selected variants, 2 truncating and 3 missense, and evaluated on expression and quantified changes in axonal morphology. RESULTS: We identified 35 patients (17 male, median age 10 years, range 2.5-23 years) carrying 32 different heterozygous variants in RORB, including 28 single-nucleotide variants or small insertions/deletions (12 missense, 12 frameshift or nonsense, 2 splice-site variants, and 2 in-frame deletions), and 4 microdeletions; de novo in 18 patients and inherited in 10. Seizures were reported in 31/35 (89%) patients, with a median age at onset of 3 years (range 4 months-12 years). Absence seizures occurred in 25 patients with epilepsy (81%). Nineteen patients experienced a single seizure type: absences, myoclonic absences, or absences with eyelid myoclonia and focal seizures. Nine patients had absence seizures combined with other generalized seizure types. One patient had presented with absences associated with photosensitive occipital seizures. Three other patients had generalized tonic-clonic seizures without absences. ID of variable degree was observed in 85% of the patients. Expression studies in cultured neurons showed shorter axons for the 5 tested variants, both truncating and missense variants, supporting an impaired protein function. DISCUSSION: In most patients, the phenotype of the RORB-related disorder associates absence seizures with mild-to-moderate ID. In silico and in vitro evaluation of the variants in our cohort, including axonal morphogenetic experiments in cultured neurons, supports their pathogenicity, showing a hypomorphic effect.

Electroclinical features and long-term outcome of cryptogenic epilepsy in children with Down syndrome.

OBJECTIVE: To describe the electroclinical features and the long-term outcomes of epilepsy in a large cohort of males and females with Down syndrome who developed epilepsy in childhood. STUDY DESIGN: Subjects with Down syndrome and cryptogenic epilepsy with onset in childhood were identified retrospectively from the databases of 16 Italian epilepsy centers over a 40-year period. For each subject, age at onset of seizures, seizure semiology and frequency, electroencephalography characteristics, treatment with antiepileptic drugs, and long-term clinical and electroencephalography outcomes were analyzed. RESULTS: A total of 104 subjects (64 males [61.5%], 40 females [38.5%]) were identified. Seizure onset occurred within 1 year of birth in 54 subjects (51.9%), between 1 and 12 years in 42 subjects (40.4%), and after 12 years in 8 subjects (7.7%). Males had a younger age of seizure onset than females. Of the 104 subjects, 51 (49.0%) had infantile spasms (IS), 35 (33.7%) had partial seizures (PS), and 18 (17.3%) had generalized seizures (GS). Febrile seizures were recorded in 5 (4.8%) subjects. Intractable seizures were observed in 23 (22.1%) subjects, including 5 (9.8%) with IS, 8 (44.4%) with PS, and 10 (31.3%) with GS. CONCLUSION: Cryptogenic epilepsy in Down syndrome may develop during the first year of life in the form of IS or, successively, as PS or GS. Electroclinical features of IS resemble those of idiopathic West syndrome, with a favorable response to treatment with adrenocorticotropic hormone seen. Patients experiencing PS and GS may be resistant to therapy with antiepileptic drugs.

A registry for Dravet syndrome: The Italian experience.

OBJECTIVES: We describe the Residras registry, dedicated to Dravet syndrome (DS) and to other phenotypes related to SCN1A mutations, as a paradigm of registry for rare and complex epilepsies. Our primary objectives are to present the tools and framework of the integrative platform, the main characteristics emerging from the patient cohort included in the registry, with emphasis on demographic, clinical outcome, and mortality. METHODS: Standardized data of enrolled pediatric and adult patients were collected in 24 Italian expert centers and regularly updated at least on a yearly basis. Patients were prospectively enrolled, at registry starting, but historical retrospective data were also included. RESULTS: At present, 281 individuals with DS and a confirmed SCN1A mutation are included. Most patients have data available on epilepsy (n = 263) and their overall neurological condition (n = 255), based on at least one follow-up update. Median age at first clinical assessment was 2 years (IQR 0-9) while at last follow-up was 11 years (IQR 5-18.5). During the 7-year activity of the registry, five patients died resulting in a mortality rate of 1.84 per 1000-person-years. When analyzing clinical changes over the first 5-year follow-up, we observed a significant difference in cognitive function (P < 0.001), an increased prevalence of behavioral disorders including attention deficit (P < 0.001), a significant worsening of language (P = 0.001), and intellectual disability (P < 0.001). SIGNIFICANCE: The Residras registry represents a large collection of standardized national data for the DS population. The registry platform relies on a shareable and interoperable framework, which promotes multicenter high-quality data collection. In the future, such integrated platform may represent an invaluable asset for easing access to cohorts of patients that may benefit from clinical trials with emerging novel therapies, for drug safety monitoring, and for delineating natural history. Its framework makes it improvable based on growing experience with its use and easily adaptable to other rare and complex epilepsy syndromes.

Focal seizures with affective symptoms are a major feature of PCDH19 gene-related epilepsy.

PURPOSE: Mutations of the protocadherin19 gene (PCDH19) cause a female-related epilepsy of variable severity, with or without mental retardation and autistic features. Despite the increasing number of patients and mutations reported, the epilepsy phenotype associated with PCDH19 mutations is still unclear. We analyzed seizure semiology through ictal video-electroencephalography (EEG) recordings in a large series of patients. METHODS: We studied 35 patients with PCDH19 gene-related epilepsy and analyzed clinical history and ictal video-EEG recordings obtained in 34 of them. KEY FINDINGS: Clusters of focal febrile and afebrile seizures had occurred in 34 patients, at a mean age of 10 months. The predominant and more consistent ictal sign was fearful screaming, occurring in 24 patients (70.5%); it was present since epilepsy onset in 12 and appeared later on, during the course in the remaining 12 patients. In infancy, fearful screaming mainly appeared within the context of seizures with prominent hypomotor semiology, whereas during follow-up it was associated with prominent early motor manifestations. In 16 patients, seizures were video-EEG recorded both at onset and during follow-up: in five patients (31%) seizure semiology remained identical, in 7 (44%) semiology varied and in four patients it was unclear whether ictal semiology changed with age. Three patients (9%) had both focal and generalized seizures, the latter consisting of absences and myoclonus. Ictal EEG during focal seizures showed a prominent involvement of the frontotemporal regions (22 patients). About 45% of patients had an alternating EEG pattern, with the ictal discharge migrating from one hemisphere to the contralateral during the same ictal event. Status epilepticus occurred in 30% of patients. Cognitive impairment occurred in 70%, ranging from mild (42%) to moderate (54%) and severe (4%); autistic features occurred in 28.5%. Direct sequencing detected 33 different heterozygous candidate mutations, 8 of which were novel. Mutations were missense substitutions (48.5%), premature termination (10 frameshift, 4 nonsense, and 2 splice-site mutations; 48.5%), and one in-frame deletion. Thirty candidate mutations (91%) were de novo. No specific genotype-phenotype correlation could be established, as missense and truncating mutations were associated with phenotypes of comparable severity. SIGNIFICANCE: Most patients with PCDH19 mutations exhibit a distinctive electroclinical pattern of focal seizures with affective symptoms, suggesting an epileptogenic dysfunction involving the frontotemporal limbic system. Awareness of this distinctive phenotype will likely enhance recognition of this disorder.

First reported case of an inherited PACS2 pathogenic variant with variable expression

Neonatal epilepsy, cerebellar dysgenesis and facial dysmorphisms may be associated with de novo PACS2 missense pathogenic variants (EIEE 66) (OMIM #618067). Here, we report a toddler boy with neonatal-onset seizures, developmental delay with hypotonia, facial dysmorphisms and prominence of the cisterna magna, mild inferior vermian and cerebellar hypoplasia. A nextgeneration epilepsy gene panel revealed a known pathogenic PACS2 missense variant, p.Glu209Lys, that was inherited from his mildly affected mother. We describe the first PACS2 pathogenic variant to be inherited, expanding the clinical spectrum, associated with a mild phenotype in the mother and a more severe phenotype in her son, in keeping with previously reported descriptions.

Brivaracetam add-on treatment in pediatric patients with severe drug-resistant epilepsy: Italian real-world evidence.

PURPOSE: To report the efficacy and tolerability of brivaracetam (BRV) in add-on therapy in pediatric patients with severe drug-resistant epilepsy. Prognostic factors of clinical outcome were also analyzed. METHODS: This Italian multicenter retrospective observational study was conducted on 45 pediatric patients with severe drug-resistant epilepsy, treated with BRV for at least 1 month and with a follow-up >6 months. Demographic, clinical, and treatment variables were assessed at T0 (baseline, BRV introduction) and T1 (6 months after BRV introduction). The response was defined as ≥50% seizure frequency reduction; responders and non-responders were then compared to assess potential prognostic factors. RESULTS: Forty-five patients (M = 28, mean age 12.4+/-4.4 years) were enrolled (focal epilepsy=14; generalized epilepsy=2; epileptic encephalopathy=29). At T1, 19/45 patients (42.2%) were responders (≥50% seizure frequency reduction), with 4 patients (8.9%) achieving a ≥ 75% seizure reduction and 2 patients (4.4%) becoming seizure free. Epilepsy onset at >12 months of age (p = 0.001), disease duration ≤6 years (p = 0.036), and lower seizure frequency at baseline (p = 0.008) were the prognostic factors significantly associated with a better prognosis. No significant difference emerged for demographics, epilepsy types/etiology, intellectual disability, or therapy variables. At T1, 21 patients (46.6%) discontinued BRV, mainly due to lack of efficacy (13 subjects; 28.9%) and adverse events in 8 patients (17.8%). CONCLUSION: Brivaracetam was an effective and tolerated treatment in pediatric patients with severe drug-resistant epilepsy, especially when the seizure onset was at >12 months of age, the epilepsy duration ≤6 years, and the seizure frequency before BRV treatment was low. Further and controlled studies are needed.