OBJECTIVE:SCN2A loss-of-function (LoF) variants are associated with epilepsy (onset age ≥ 3 months), intellectual disability (ID), and autism spectrum disorder (ASD). Despite numerous identified variants and the description of phenotypic subgroups, relationships between Nav1.2 channel dysfunction and clinical phenotypes remain unclear. This study examined how distinct LoF mechanisms relate to phenotypic outcomes. METHODS:Whole-cell patch-clamp electrophysiology was used to characterize 15 presumed LoF SCN2A variants. Mechanism-phenotype correlations were assessed in 33 patients with these variants (six recurrent) and 41 patients with 15 previously characterized LoF variants (four recurrent). Phenotypic subgroups were categorized as later onset epilepsy-midinfancy (onset between 3 and 18 months), later onset epilepsy-childhood (onset after 18 months), ID/ASD without epilepsy, and "other" for unclassified cases. RESULTS:Of the 15 electrophysiologically characterized SCN2A variants, 11 caused total Nav1.2 LoF, three caused partial LoF, and one showed mixed LoF and gain-of-function (GoF) effects. Among previously published variants, seven showed total LoF, five partial LoF, and two mixed LoF/GoF, and one was undetermined. Across both cohorts, seven of 10 recurrent variants (70%) were associated with multiple phenotypic subgroups. Partial or total Nav1.2 LoF variants were identified in all subgroups. Notably, a midinfancy epilepsy phenotype was observed in 22 of 24 individuals (92%) carrying a mixed LoF variant, with phenotype data unavailable for seven additional individuals. A novel LoF-associated phenotype-episodic ataxia with or without developmental delay or ID-was identified in five of six individuals with the L1650P variant. Although episodic ataxia has been previously associated with GoF variants in SCN2A, this is the first reported instance in individuals with a confirmed LoF variant. SIGNIFICANCE:Distinct SCN2A LoF phenotypes cannot be reliably linked to specific biophysical mechanisms, as both total and partial Nav1.2 LoF occurs across diverse phenotypes. For efficient personalized treatment, it is crucial not to rely solely on clinical phenotype to predict the underlying LoF mechanism.

Abstract Background Attention to non-seizure outcomes in Developmental and/or Epileptic Encephalopathies (DEs, EEs, DEEs) is growing, and there is increasing interest in understanding key determinants of health-related quality of life (HRQoL) in this population. This study investigates personal and family HRQoL in a real-world pediatric cohort with DEs, EEs, or DEEs and explores predictors of reduced HRQoL. Methods Single-center, cross-sectional study conducted at a tertiary pediatric neurology center. Individuals with DE, EE or DEE aged 1–20 years were enrolled. Patient and family HRQoL were measured using the Pediatric Quality of Life Inventory™ (PedsQL™ Epilepsy Module and PedsQL™ Family Impact Module). Demographics, epilepsy history and functional scores were collected. Analyses included descriptive statistics, Mann-Whitney U tests, Spearman correlations, and exploratory bootstrapped multivariable linear regression models. Results One hundred patients (58 males; mean age: 9.9 ± 4.1 years) and caregivers participated. Patients’ HRQoL was most impaired in Cognitive (16.7/100) and Executive Functioning (25.0/100). Drug-resistant epilepsy was independently associated with lower patient HRQoL across multiple PedsQL™ Epilepsy Module subscales. Additional determinants of poorer patient HRQoL in specific domains included gastrointestinal comorbidities, daily seizures, early epilepsy onset, and higher modified Rankin scale scores. Family HRQoL was also impaired, especially in Worry (35/100) and Daily Activities (41.7/100) subscales. Lower overall Family Impact scores were independently associated with a history of intensive care hospitalization (b = −12.2, p = 0.004), lower patient Sleep/Rest scores (b = 0.3, p = 0.001), and Mood/Behavior scores (b = 0.2, p = 0.005). Conclusions DEs, EEs and DEEs substantially affect both patient and family HRQoL. Patient HRQoL was particularly impaired in cognitive and executive functioning domains, whereas family burden was most evident in terms of worry and daily activities impairment. Drug-resistant epilepsy, daily seizure frequency, gastrointestinal comorbidities, greater functional impairment, and earlier epilepsy onset were associated with poorer patient HRQoL, whereas child sleep/rest and mood/behavior difficulties were independently associated with greater family burden. These findings support the importance of multidisciplinary approaches addressing both seizure-related and non-seizure-related outcomes in affected children and families.

Sleep-related hypermotor epilepsy is characterized by complex seizures predominantly during sleep, marked by hyperkinetic movements and/or asymmetric tonic/dystonic posturing. The etiology often remains unknown, but when identified it is attributed to genetic and/or structural factors, implicating genes such as CHRNA4, CHRNB2, CHRNA2, KCNT1, and DEPDC5. ADGRV1 pathogenic variants are associated with an autosomal recessive form IIC of Usher syndrome and several epilepsy types, including generalized auditory-induced seizures, focal epilepsy, genetic generalized epilepsy, and epileptic encephalopathy. An association between SHE and ADGRV1 gene has never been described. Here we describe a pediatric patient with SHE harboring a de novo heterozygous pathogenic variant on the ADGRV1 gene (c.14165A>G; p.Glu4722Gly). Our findings prompt discussion about the potential phenotype expansion associated with this ADGRV1 variant and its pathogenic link with SHE.

Lennox-Gastaut syndrome (LGS) is one of the most severe, yet one of the most discussed, childhood-onset developmental and epileptic encephalopathies (DEEs). Dissent among epileptologists on the definition and minimum set of electroclinical features derives from the high etiological heterogeneity within the syndrome, which could make its prevalence overestimated. However, in recent years, our diagnostic strategies, including both high-resolution magnetic resonance imaging and next-generation sequencing techniques, have enabled us to disentangle many cases previously classified as "idiopathic." In addition, some electroencephalographic and circulating biomarkers have been identified that could predict disease progression and treatment response if confirmed in larger patient populations. As our diagnostic capacity increases, so do our treatment strategies. Although progress has been made, the implementation of better clinical trial designs, individualized treatments, and therapies that address the genetic roots of the disease remains necessary in clinical practice. A lot is being done in this direction, thanks to the involvement of families and the creation of international networks, such as the ERNs, which are rapidly promoting collaboration among highly specialized centers and the establishment of disease registries to shed light on the natural history of LGS. Yet, many unmet needs still afflict patients and their families, including uncertainties arising from the transition process and a lack of administrative support and comprehensive care as patients transition into adulthood. This article summarizes these key challenges in diagnosing, treating, and caring for patients with LGS, as well as the roadmap to enhanced future care discussed during the international LGS meeting held in Genoa.

Sunflower syndrome, a rare photosensitive epilepsy characterized by handwaving episodes and fixation on light sources, remains poorly understood, especially regarding its neuropsychological profile. This study provides a detailed cognitive evaluation of two patients, revealing a likely disruption in the visual dorsal stream, with particular involvement of the ventral attention network (VAN). Despite normal overall intellectual functioning, both patients exhibited significant deficits in Processing Speed Index and inhibitory control, indicating selective executive dysfunction. Coupled with EEG anomalies predominantly in the right frontal lobe, these findings suggest right hemisphere involvement, potentially along the VAN pathway. This study highlights the need for further research, particularly functional neuroimaging, to better understand the neurocognitive aspects of sunflower syndrome and its impact on patients' quality of life.

Knowledge of the natural history of CDKL5 deficiency disorder (CDD) is limited to the results of cross-sectional analysis of largely pediatric cohorts. Assessment of outcomes in adulthood is critical for clinical decision-making and future precision medicine approaches but is challenging because of the diagnostic gap and duration of follow-up that would be required for prospective studies. We aimed to delineate the natural history retrospectively from adulthood. We analyzed clinical data about an international cohort of 67 adults with CDD. We analyzed demographic, phenotypic, CDKL5 Developmental Score (CDS), and treatment data, and tested associations with genetic factors, sex, and a positive or negative history of neonatal seizures, as an early predictor of prognosis. All but one of 67 adults (55 females, median age of 24 years at last follow-up) had epilepsy, typically beginning with epileptic spasms or tonic seizures before 4 months of age. Focal-onset and non-motor seizures emerged later. Fewer than a third had been documented as having bilateral tonic-clonic seizures or status epilepticus. Seizures often improved with age, but 73% had never experienced more than 6 months of seizure-freedom. Clobazam, sodium valproate, and lamotrigine were the most frequently prescribed antiseizure medications, but no specific treatment demonstrated superiority. Common comorbidities included movement disorders, visual impairment, sleep disorders, constipation, and scoliosis. All participants had intellectual disability, 75% had not acquired speech and 45% had regressed developmentally. 16% never achieved any CDS skill, but most attained at least three, and 28% attained six or all seven. By adulthood, half of those who had achieved any CDS skill retained all their CDS skills. The skills most frequently lost were independent walking and standing. Those with a history of neonatal seizures tended to attain fewer CDS skills and were more likely to have abnormal muscle tone in adulthood, atrioventricular conduction delay, and potential complications of their illness and treatment. Individuals carrying missense variants attained more CDS skills than those with other variants and were more likely to lose skills in adulthood and develop anxiety, possibly reflecting the limited neurodevelopment of those with non-missense variants, who manifested a more multisystemic disorder. In summary, retrospective data from adulthood elucidates the evolution of symptoms, variation in developmental outcomes, and the treatment landscape in CDKL5 deficiency disorder. Presence a non-missense variants or a history of neonatal seizures indicates a more complex disorder and lower developmental trajectory. Our findings will inform management decisions, prognostication, and the design of clinical trials in CDKL5 Deficiency Disorder.

O’Donnell-Luria-Rodan (ODLURO) syndrome is an autosomal dominant disorder caused by mutations in the KMT2E gene. The clinical phonotype of the affected individuals is typically characterized by global developmental delay, autism, epilepsy, hypotonia, macrocephaly, and very mild dysmorphic facial features. In this report, we describe the case of a 6-year-old boy with ODLURO syndrome who is a carrier of the synonymous mutation c.186G>A (p.Ala62=) in the KMT2E gene, predicted to alter splicing by in silico tools. Given the lack of functional studies on the c.186G>A variant, in order to assess its potential functional effect, we sequenced the patient’s cDNA demonstrating its impact on the mechanism of splicing. To the best of our knowledge, our patient is the second to date reported carrying this synonymous mutation, but he is the first whose functional investigation has confirmed the deleterious consequence of the variant, resulting in exon 4 skipping. Additionally, we suggest a potential etiological mechanism that could be responsible for the aberrant splicing mechanism in KMT2E.

BackgroundEpilepsy is a hallmark of IQSEC2-related encephalopathy within a phenotypic variability ranging between early onset epileptic and developmental encephalopathy and X-linked intellectual disability with epilepsy.Patients and MethodsData including demographic aspects, gene variants, seizure semiology and timing, EEG features, neuroimaging and response to therapy were retrospectively collected in patients with IQSEC2-related epilepsy referring to 8 Italian tertiary centres.ResultsThe reported cohort included 11 patients (8 males and 3 females). Mean age at the onset of epilepsy was 3.90±2.80 years. No cases were reported in the first year of life. No specific epileptic syndromes were recognized. Predominant seizure-types in the age range 12-36 months included focal onset tonic seizures with impaired awareness, myoclonic seizures, and late onset spasms. Generalized motor seizures were predominant in patients between 3 and 6 years and between 12 and 18 years while focal motor seizures with impaired awareness were the most represented types between 6 and 12 years. No patients experienced status epilepticus. EEG patterns included a delayed maturation of EEG organization, irregular focal or diffuse slow activity, multifocal or diffuse epileptiform abnormalities. No structural epileptogenic lesions were detected at MRI. Valproate, lamotrigine, clobazam, topiramate and levetiracetam were the most used antiseizure medication. Complete seizure freedom was achieved only in 2 patients.ConclusionsOnset of epilepsy after the first year of age, predominance of focal seizures with impaired awareness and generalized motor seizures, no pathognomonic underlying epileptic syndrome and infrequent occurrence of status epilepticus emerged as the main features of IQSEC2-related epilepsy phenotype.

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

OBJECTIVE:Status epilepticus (SE) is a neurological emergency in childhood, often leading to neuronal damage and long-term outcomes. The study aims to identify barriers in the pre-hospital and in-hospital management of community-onset pediatric SE and to evaluate the effectiveness of pediatric scores on outcomes prediction. METHODS:This monocentric observational retrospective cohort study included patients treated for community-onset pediatric SE in a tertiary care hospital between 2010 and 2021. Data were extracted following Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. Inclusion criteria were community-onset SE (according to the International League Against Epilepsy [ILAE] Task Force on SE Classification), admission to the pediatric emergency department (PED), age: 1 month to 18 years. Pre-hospital, in-hospital management and outcomes were analyzed. Pediatric scores for prediction of clinical worsening (Pediatric Early Warning Score - PEWS) and SE outcome (Status Epilepticus in Pediatric patients Severity Score - STEPSS; Pre-status Epilepticus PCPCS, background Electroencephalographic abnormalities, Drug refractoriness, Semiology and critical Sickness Score - PEDSS) were retrospectively assessed for their accuracy in predicting short-term and long-term outcomes. RESULTS:A total of 103 consecutive episodes of SE were included. Out-of-hospital rescue medications administration occurred in 54.4% of cases and was associated with higher SE resolution rate before PED admission (48.2% vs 27.6%, p = .033). Longer in-PED time to treatment was observed in case of delay to PED referral (r = 0.268, p = .048) or non-red triage labels (12 vs 5 min, p = 0.032), and was associated with longer in-PED duration of SE (r = 0.645, p < .001). Longer SE duration was observed in episodes leading to hospitalization compared to those discharged (50 vs 16 min, p < .001). In-PED electroencephalography (EEG) recordings were available in 39.8% of events. Predictive scores varied in accuracy, with PEWS ≥5 showing high sensitivity for intensive care unit (ICU) admission but low specificity. No patients died, 6.3% of SE was refractory. SIGNIFICANCE:Effective pre-hospital administration of rescue medications and prompt PED management are crucial to reduce SE duration and improve outcomes. Predictive scores can aid in assessment of the severity and prognosis of SE; their utility is still not defined. Identifying and addressing actionable care barriers in SE management pathways is essential to enhance patient outcomes in pediatric SE.

ObjectivePerampanel, an antiseizure drug with alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor antagonist properties, may have a targeted effect in genetic epilepsies with overwhelming glutamate receptor activation. Epilepsies with loss of gamma-aminobutyric acid inhibition (e.g., SCN1A), overactive excitatory neurons (e.g., SCN2A, SCN8A), and variants in glutamate receptors (e.g., GRIN2A) hold special interest. We aimed to collect data from a large rare genetic epilepsy cohort treated with perampanel, to detect possible subgroups with high efficacy. MethodsThis multicenter project was based on the framework of NETRE (Network for Therapy in Rare Epilepsies), a web of pediatric neurologists treating rare epilepsies. Retrospective data from patients with genetic epilepsies treated with perampanel were collected. Outcome measures were responder rate (50% seizure reduction), and percentage of seizure reduction after 3 months of treatment. Subgroups of etiologies with high efficacy were identified. ResultsA total of 137 patients with 79 different etiologies, aged 2 months to 61 years (mean = 15.48 +/- 9.9 years), were enrolled. The mean dosage was 6.45 +/- 2.47 mg, and treatment period was 2.0 +/- 1.78 years (1.5 months-8 years). Sixty-two patients (44.9%) were treated for >2 years. Ninety-eight patients (71%) were responders, and 93 (67.4%) chose to continue therapy. The mean reduction in seizure frequency was 56.61% +/- 34.36%. Sixty patients (43.5%) sustained >75% reduction in seizure frequency, including 38 (27.5%) with >90% reduction in seizure frequency. The following genes showed high treatment efficacy: SCN1A, GNAO1, PIGA, PCDH19, SYNGAP1, POLG1, POLG2, and NEU1. Eleven of 17 (64.7%) patients with Dravet syndrome due to an SCN1A pathogenic variant were responders to perampanel treatment; 35.3% of them had >90% seizure reduction. Other etiologies remarkable for >90% reduction in seizures were GNAO1 and PIGA. Fourteen patients had a continuous spike and wave during sleep electroencephalographic pattern, and in six subjects perampanel reduced epileptiform activity. SignificancePerampanel demonstrated high safety and efficacy in patients with rare genetic epilepsies, especially in SCN1A, GNAO1, PIGA, PCDH19, SYNGAP1, CDKL5, NEU1, and POLG, suggesting a targeted effect related to glutamate transmission.

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.

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.

Mutations in the KCNA1 gene, encoding the voltage-gated potassium channel Kv1.1, have been associated with a spectrum of neurological phenotypes, including episodic ataxia type 1 and developmental and epileptic encephalopathy. We have recently identified a de novo variant in KCNA1 in the highly conserved Pro-Val-Pro motif within the pore of the Kv1.1 channel in a girl affected by early onset epilepsy, ataxia and developmental delay. Other mutations causing severe epilepsy are located in Kv1.1 pore domain. The patient was initially treated with a combination of antiepileptic drugs with limited benefit. Finally, seizures and ataxia control were achieved with lacosamide and acetazolamide. The aim of this study was to functionally characterize Kv1.1 mutant channel to provide a genotype–phenotype correlation and discuss therapeutic options for KCNA1-related epilepsy. To this aim, we transfected HEK 293 cells with Kv1.1 or P403A cDNAs and recorded potassium currents through whole-cell patch-clamp. P403A channels showed smaller potassium currents, voltage-dependent activation shifted by +30 mV towards positive potentials and slower kinetics of activation compared with Kv1.1 wild-type. Heteromeric Kv1.1+P403A channels, resembling the condition of the heterozygous patient, confirmed a loss-of-function biophysical phenotype. Overall, the functional characterization of P403A channels correlates with the clinical symptoms of the patient and supports the observation that mutations associated with severe epileptic phenotype cluster in a highly conserved stretch of residues in Kv1.1 pore domain. This study also strengthens the beneficial effect of acetazolamide and sodium channel blockers in KCNA1 channelopathies.

Variants in SCN2A, encoding the voltage-gated sodium channel Nav1.2, are commonly associated with developmental and epileptic encephalopathy. Although animal studies demonstrated a role for Nav1.2 in intraventricular conduction, heart anomalies have been only occasionally described in patients with SCN2A variants. In this report we trace the prenatal and neonatal history of a fetus/newborn with a de novo pathogenic variant in the SCN2A gene identified by prenatal trio whole-exome sequencing (WES). In addition to more typically SCN2A-associated neurological manifestations, the patient showed sustained tachyarrhythmia, potentially expanding the phenotypic spectrum associated with SCN2A variants and raising the question of whether cardiological assessment and prompt pharmacological intervention in SCN2A channelopathies to avoid heart complications might be beneficial. To the best of our knowledge, this represents the first clinical description of a SCN2A phenotype in a prenatal setting, as well as the first SCN2A diagnosis achieved by prenatal trio-WES approach.

Background and ObjectivesClinical manifestations in STXBP1 developmental and epileptic encephalopathy (DEE) vary in severity and outcome, and the genotypic spectrum is diverse. We aim to trace the neurodevelopmental trajectories in individuals with STXBP1-DEE and dissect the relationship between neurodevelopment and epilepsy.MethodsRetrospective standardized clinical data were collected through international collaboration. A composite neurodevelopmental score system compared the developmental trajectories in STXBP1-DEE.ResultsForty-eight patients with de novo STXBP1 variants and a history of epilepsy were included (age range at the time of the study: 10 months to 35 years, mean 8.5 years). At the time of inclusion, 65% of individuals (31/48) had active epilepsy, whereas 35% (17/48) were seizure free, and 76% of those (13/17) achieved remission within the first year of life. Twenty-two individuals (46%) showed signs of developmental impairment and/or neurologic abnormalities before epilepsy onset. Age at seizure onset correlated with severity of developmental outcome and the developmental milestones achieved, with a later seizure onset associated with better developmental outcome. In contrast, age at seizure remission and epilepsy duration did not affect neurodevelopmental outcomes. Overall, we did not observe a clear genotype-phenotype correlation, but monozygotic twins with de novo STXBP1 variant showed similar phenotype and parallel disease course.DiscussionThe disease course in STXBP1-DEE presents with 2 main trajectories, with either early seizure remission or drug-resistant epilepsy, and a range of neurodevelopmental outcomes from mild to profound intellectual disability. Age at seizure onset is the only epilepsy-related feature associated with neurodevelopment outcome. These findings can inform future dedicated natural history studies and trial design.

Objective: This review article focuses on clinical and genetic features of paroxysmal neurological disorders featuring episodic ataxia (EA) and epilepsy and help clinicians recognize, diagnose, and treat patients with coexisting EA and epilepsy. It also provides an overview of genes and molecular mechanisms underlying these intriguing neurogenetic disorders.Methods: Based on a literature review on Pubmed database, a list of genes linked to paroxysmal neurological disorders featuring EA and epilepsy were compiled. Online Mendelian Inheritance in Man (OMIM) was used to identify further reports relevant to each gene. Results: Among the various forms of EAs, only EA1 (KCNA1), EA2 (CACNA1A), EA5 (CACNB4), EA6 (SLC1A3), and EA9 (SCN2A) phenotypes with associated epilepsy have been described. Next-generation sequencing (NGS) has helped in the identification of other genes (e.g.: KCNA2, ATP1A3, SLC2A1, PRRT2) which have shown an overlapping phenotype with EA and epilepsy.Conclusion: Overlapping clinical features between EA and epilepsy may hinder an accurate classification, and complex genotype-phenotype correlation may often lead to misdiagnosis. NGS has increased the awareness of common genetic etiologies for these conditions. In the future, extensive genetic and phenotypic characterizations can help us to elucidate the boundaries of a wide phenotypic spectrum. These insights may help develop new precision therapies in paroxysmal neurological disorders featuring EA and epilepsy.

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. De-mographic, 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.

Weiss-Kruszka syndrome is a recently described genetic disorder characterized by craniofacial features, ptosis, dysgenesis of the corpus callosum, and neurodevelopmental impairment. It is caused by heterozygous loss-of-function variantsin ZNF462 gene. During the time, the original phenotype was expanded, including several complications, sensorineural hearing loss, congenital hypogonadotropic hypogonadism with anosmia and complete growth hormone deficiency associated with empty sella syndrome. Here we report the first case of Weiss-Kruszka syndrome, associated to a de novo 9q31.1q31.3 microdeletion showing an acute lymphoblastic leukemia. A speculation on the contribution of our case to the phenotypic expansion of WSKA is here discussed. More clinical and functional studies are needed to elucidate this association. A possible expansion of the WSKA phenotype is discussed.