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Background and ObjectivesWe sought to identify early factors associated with relapse and outcome in paediatric-onset myelin oligodendrocyte glycoprotein antibody-associated disorders (MOGAD).MethodsIn a multicenter retrospective cohort of pediatric MOGAD (≤18 years), onset features and treatment were compared in patients with monophasic vs relapsing disease (including cases with follow-up ≥12 months after onset or relapse at any time) and in patients with final Expanded Disability Status Scale (EDSS) 0 vs ≥1 at last follow-up (including cases with follow-up >3 months after last event or EDSS0 at any time). Multivariable logistic regression models were used to evaluate factors associated with relapsing disease course and EDSS ≥ 1 at final follow-up.ResultsSeventy-five children were included (median onset age 7 years; median 30 months of follow-up). Presentation with acute disseminated encephalomyelitis was more frequent in children aged 8 years or younger (66.7%, 28/42) than in older patients (30.3%, 10/33) (p= 0.002), whereas presentation with optic neuritis was more common in children older than 8 years (57.6%, 19/33) than in younger patients (21.4%, 9/42) (p= 0.001). 40.0% (26/65) of patients relapsed. Time to first relapse was longer in children aged 8 years or younger than in older patients (median 18 vs 4 months) (p= 0.013). Factors at first event independently associated with lower risk of relapsing disease course were immunotherapy p= 0.009), corticosteroid treatment for ≥5 weeks (6.7-fold reduced odds of relapse, OR 0.15, 95% CI 0.03–0.80,p= 0.026), and abnormal optic nerves on onset MRI (12.5-fold reduced odds of relapse, OR 0.08, 95% CI 0.01–0.50,p= 0.007). 21.1% (15/71) had EDSS ≥ 1 at final follow-up. Patients with a relapsing course had a higher proportion of final EDSS ≥ 1 (37.5%, 9/24) than children with monophasic disease (12.8%, 5/39) (p= 0.022, univariate analysis). Each 1-point increment in worst EDSS at onset was independently associated with 6.7-fold increased odds of final EDSS ≥ 1 (OR 6.65, 95% CI 1.33–33.26,p= 0.021).DiscussionAt first attack of pediatric MOGAD, early immunotherapy, longer duration of corticosteroid treatment, and abnormal optic nerves on MRI seem associated with lower risk of relapse, whereas higher disease severity is associated with greater risk of final disability (EDSS ≥ 1).

Background and ObjectivesBRAT1encephalopathy is an ultra-rare autosomal recessive neonatal encephalopathy. We delineate the neonatal electroclinical phenotype at presentation and provide insights for early diagnosis.MethodsThrough a multinational collaborative, we studied a cohort of neonates with encephalopathy associated with biallelic pathogenic variants inBRAT1for whom detailed clinical, neurophysiologic, and neuroimaging information was available from the onset of symptoms. Neuropathologic changes were also analyzed.ResultsWe included 19 neonates. Most neonates were born at term (16/19) from nonconsanguineous parents. 15/19 (79%) were admitted soon after birth to a neonatal intensive care unit, exhibiting multifocal myoclonus, both spontaneous and exacerbated by stimulation. 7/19 (37%) had arthrogryposis at birth, and all except 1 progressively developed hypertonia in the first week of life. Multifocal myoclonus, which was present in all but 1 infant, was the most prominent manifestation and did not show any EEG correlate in 16/19 (84%). Video-EEG at onset was unremarkable in 14/19 (74%) infants, and 6 (33%) had initially been misdiagnosed with hyperekplexia. Multifocal seizures were observed at a median age of 14 days (range: 1–29). During the first months of life, all infants developed progressive encephalopathy, acquired microcephaly, prolonged bouts of apnea, and bradycardia, leading to cardiac arrest and death at a median age of 3.5 months (range: 20 days to 30 months). Only 7 infants (37%) received a definite diagnosis before death, at a median age of 34 days (range: 25–126), and almost two-thirds (12/19, 63%) were diagnosed 8 days to 12 years postmortem (median: 6.5 years). Neuropathology examination, performed in 3 patients, revealed severely delayed myelination and diffuse astrogliosis, sparing the upper cortical layers.DiscussionBRAT1encephalopathy is a neonatal-onset, rapidly progressive neurologic disorder. Neonates are often misdiagnosed as having hyperekplexia, and many die undiagnosed. The key phenotypic features are multifocal myoclonus, an organized EEG, progressive, persistent, and diffuse hypertonia, and an evolution into refractory multifocal seizures, prolonged bouts of apnea, bradycardia, and early death. Early recognition ofBRAT1encephalopathy allows for prompt workup, appropriate management, and genetic counseling.

Objective To investigate the mechanisms by which Perampanel (PER) reduces the severity of action myoclonus, we studied on MEG signals the changes occurring in cortico-muscular coherence (CMC) and cortico-cortical connectivity in patients with progressive myoclonus epilepsies. Methods The subjects performed an isometric extension of the hand; CMC and cortico-cortical connectivity were assessed using autoregressive models and generalized partial-directed coherence. The contralateral (Co) sensors showing average CMC values >0.7 of the maximum (set to 1) were grouped as central (C) regions of interest (ROI), while adjacent sensors showing CMC values >0.3 were grouped as Surrounding (Sr) ROIs. Results Under PER treatment, CMC decreased on Co C and Sr ROIs, but also on homologous ipsilateral (Ip) ROIs; out-degrees and betweenness centrality increased in Co ROIs and decreased in Ip ROIs. The flow from Ip to Co ROIs and from activated muscles to Ip C ROI decreased. Conclusion The improvement of myoclonus corresponded to decreased CMC and recovered leadership of the cortical regions directly involved in the motor task, with a reduced interference of ipsilateral areas. Significance Our study highlights on mechanisms suitable to treating myoclonus and suggests the role of a reduced local synchronization together a better control of distant synaptic effects.

Febrile‐infection related epilepsy syndrome (FIRES) is a devastating neurological condition characterized by a febrile illness preceding new onset refractory status epilepticus (NORSE). Increasing evidence suggests innate immune dysfunction as a potential pathological mechanism. We report an international retrospective cohort of 25 children treated with anakinra, a recombinant interleukin‐1 receptor antagonist, as an immunomodulator for FIRES. Anakinra was potentially safe with only one child discontinuing therapy due to infection. Earlier anakinra initiation was associated with shorter duration of mechanical ventilation, ICU and hospital length of stay. Our retrospective data lay the groundwork for prospective consensus‐driven cohort studies of anakinra in FIRES.

Objective: Autosomal recessive pathogenic variants of the SLC13A5 gene are associated with severe neonatal epilepsy, developmental delay, and tooth hypoplasia/hypodontia. We report on 14 additional patients and compare their phenotypic features to previously published patients to identify the clinical hallmarks of this disorder. Methods: We collected clinical features of 14 patients carrying biallelic variants in SLC13A5 and performed a PubMed search to identify previously published patients. Results: All patients presented clonic or tonic seizures in the first days of life, evolving into status epilepticus in 57%. Analysis of seizure frequency and developmental milestones divided into five epochs showed an evolutionary trajectory of both items. In the first 3 years of life, 72% of patients had weekly/monthly seizures, often triggered by fever; 14% were seizure-free. Between the ages of 3 and 12 years, 60% become seizure-free; in the following years, up to age 18 years, 57% were seizure-free. After the age of 18 years, all three patients reaching this age were seizure-free. Similarly, 86% of patients at onset presented mild to moderate developmental impairment and diffuse hypotonia. In late childhood, all had developmental delay that was severe in most. Benzodiazepines, phenobarbital, phenytoin, and carbamazepine were the most effective drugs. Eight probands carried heterozygous compound variants, and homozygous pathogenic variants occurred in six. Literature review identified 45 patients carrying SLC13A5 gene pathogenic variants whose clinical features overlapped with our cohort. A peculiar and distinguishing sign is the presence of tooth hypoplasia and/or hypodontia in most patients. Significance: Autosomal recessive pathogenic variants in SLC13A5 are associated with a distinct neonatal epileptic encephalopathy evolving into severe cognitive and motor impairment, yet with seizures that settle down in late childhood. Tooth hypoplasia or hypodontia remains the peculiar feature. The SLC13A5 gene should be screened in neonatal epileptic encephalopathies; its recessive inheritance has relevance for genetic counseling.

We report the atypical presentation of Lafora disease in a Senegalese girl carrying the homozygous variant, c.560A>C, in the NHLRC1 gene. At 13 years, the patient developed myoclonic and visual seizures, progressive psychomotor slowing, and cognitive decline. At 14 years, a neurological examination showed severe hypomimia, bradykinesia, rigidity and low-amplitude myoclonic jerks. Flash-visual and somatosensory evoked potentials showed an increased amplitude of the cortical components, while an electroretinogram showed attenuated responses. An EEG showed diffuse polyspikes associated with positive-negative jerks as well as posterior slow waves and irregular spikes. The electroclinical picture suggested the diagnosis of Lafora disease regarding the association of visual seizures, cognitive deterioration, and action myoclonus, together with the EEG and evoked potential findings. Two uncommon findings were the prominence of extrapyramidal signs in the early stage of disease (which are rarely reported) and attenuation of electroretinal responses. We consider that Lafora disease should be included in the diagnostic work-up for juvenile Parkinsonism, when associated with epilepsy.

AMPA-type glutamate receptors (AMPARs) are postsynaptic ionotropic receptors which mediate fast excitatory currents. AMPARs have a heterotetrameric structure, variably composed by the four subunits GluA1-4 which are encoded by genes GRIA1-4. Increasing evidence support the role of pathogenic variants in GRIA1-4 genes as causative for syndromic intellectual disability (ID). We report an Italian pedigree where some male individuals share ID, seizures and facial dysmorphisms. The index subject was referred for severe ID, myoclonic seizures, cerebellar signs and short stature. Whole exome sequencing identified a novel variant in GRIA3, c.2360A G, p.(Glu787Gly). The GRIA3 gene maps to chromosome Xq25 and the c.2360A G variant was transmitted by his healthy mother. Subsequent analysis in the family showed a segregation pattern compatible with the causative role of this variant, further supported by preliminary functional insights. We provide a detailed description of the clinical evolution of the index subjects and stress the relevance of myoclonic seizures and cerebellar syndrome as cardinal features of his presentation.

Rationale Juvenile myoclonic epilepsy (JME) and juvenile absence epilepsy (JAE) are generalized epileptic syndromes presenting in the same age range. To explore whether uneven network dysfunctions may underlie the two different phenotypes, we examined drug-naive patients with JME and JAE at the time of their earliest presentation. Methods Patients were recruited based on typical JME (n = 23) or JAE (n = 18) presentation and compared with 16 age-matched healthy subjects (HS). We analyzed their awake EEG signals by Partial Directed Coherence and graph indexes. Results Out-density and betweenness centrality values were different between groups. With respect to both JAE and HS, JME showed unbalanced out-density and out-strength in alpha and beta bands on central regions and reduced alpha out-strength from fronto-polar to occipital regions, correlating with photosensitivity. With respect to HS, JAE showed enhanced alpha out-density and out-strength on fronto-polar regions. In gamma band, JAE showed reduced Global/Local Efficiency and Clustering Coefficient with respect to HS, while JME showed more scattered values. Conclusions Our data suggest that regional network changes in alpha and beta bands underlie the different presentation distinguishing JME and JAE resulting in motor vs non-motor seizures characterizing these two syndromes. Conversely, impaired gamma-activity within the network seems to be a non-local marker of defective inhibition.

Pathogenic variants in the SCN8A gene have been associated with a broad phenotypic spectrum, ranging from benign familial infantile seizures to severe, early-onset developmental and epileptic encephalopathy. This spectrum also includes an "intermediate phenotype" characterized by different degrees of cognitive disability, mild neurological impairment, and therapeutically manageable epilepsy. We report on a child harbouring a de novo, novel SCN8A deletion, whose clinical picture is consistent with an SCN8A-related "intermediate phenotype". This patient's peculiar feature is the occurrence of paroxysmal tonic upgaze (PTU), a non-epileptic disorder consisting of sustained conjugate upward deviation of the eyes, with neck flexion, and downbeat saccades. PTU has been described in otherwise healthy children, as well as in a few genetic syndromes, but has never been observed in SCN8A-related phenotypes. This report, therefore, adds a new symptom to the spectrum of movement disorders associated with SCN8A-related developmental and epileptic encephalopathy. In this short communication, we provide video-EEG documentation of PTU and seizures, and discuss the challenging differential diagnosis between the two symptoms.

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The role of inflammation is increasingly recognized in triggering or sustaining epileptic activity. In the last decades, increasing research has provided definite evidence to support the link between immunity, inflammatory process, and epilepsy. Neuro- and systemic inflammation play a pivotal role in driving epileptogenesis through different pathogenetic mechanisms: the activation of innate immunity in glia, neurons, and microvasculature, the brain mediated by blood-brain barrier (BBB) impairment, and the imbalance of pro- and anti-inflammatory molecules produced by both arms of immunity. More recently, research has focused on the adverse effects of maternal or early-life immune activation and cytokine imbalance on fetal neurodevelopment and postnatal epilepsy. A complex crosstalk between the immune and nervous system, and a crucial interplay of genetic, epigenetic, and environmental factors may influence structures and functions of the developing brain. A better understanding of the inflammatory process in promoting epilepsy implies that targeting specific pathways may be effective in seizure control. Multiple targets have been identified so far, and several antiseizure interventions are obtained by inhibiting inflammatory signaling or protecting/restoring BBB. All this evidence has changed the field of epilepsy research and neuropharmacology. Further developments and new treatments will rapidly emerge to improve seizure management in inflammation-related epilepsies. This article is part of the Special Issue "Severe Infantile Epilepsies".

Patients with autoimmune encephalitis (AE) are likely to exhibit an acute onset of severe psychiatric features, including psychosis and/or catatonia. Based on the high prevalence of catatonia in AE and our clinical experience, we hypothesized that catatonia might be a marker of severity requiring more aggressive treatment approaches.To reach a sufficient number of cases with brain-autoimmune conditions, we pooled two samples (N = 58): the first from the French National Network of Rare Psychiatric diseases and the second from the largest Italian neuro-pediatrics center for encephalopathies. Autoimmune conditions were diagnosed using a multidisciplinary approach and numerous paraclinical investigations. We retrospectively compared patients with and without catatonia for psychiatric and non-psychiatric clinical features, biological and imaging assessments, type of immunotherapy used and outcomes.The sample included 25 patients (43%) with catatonia and 33 (57%) without catatonia. Forty-two patients (72.4%) had a definite AE (including 27 anti-NMDA receptor encephalitis) and 16 (27.6%) suspected autoimmune encephalitis. Patients with catatonia showed significantly more psychotic features [18 (72%) vs 9 (27.3%), p 0.001)] and more movement disorders [25 (100%) vs 20 (60.6%), p 0.001] than patients without catatonia. First line (corticoids, immunoglobulin and plasma exchanges) and second line (e.g., rituximab) therapies were more effective in patients with catatonia, with 24 (96%) vs 22 (66.7%) (p = 0.006) and 17 (68%) vs 9 (27.3%) (p = 0.002), respectively. However, those with catatonia received more combinations of first and second line treatments and had more relapses during outcomes.Despite its exploratory design, the study supports the idea that autoimmune catatonia may be a marker of severity and morbidity in terms of initial presentation and relapses, requiring the need for early and aggressive treatment.

The altered function of the Hyperpolarization-activated Cyclic-Nucleotide-gated (HCN) ion channels plays an important role in the pathogenesis of epilepsy in humans. In particular, HCN1 missense mutations have been recently identified in patients with different epileptic phenotypes, varying from mild to severe. Their electrophysiological characterization shows that mutated channels can act both with loss-of-function and gain-of-function mechanisms of action, without an evident correlation with the phenotype. In search for a correlation between clinical features and biophysical properties of the mutations, in this work we considered sixteen HCN1 mutations, found in eighteen Early Infantile Epileptic Encephalopathy (EIEE) patients. Statistical analysis did not establish any significant correlation between the clinical parameters and the current properties of the mutant channels. The lack of significance of our results could depend on the small number of mutations analyzed, epilepsy-associated with certainty. With the progressive increase of Next Generation Sequencing in patients with early-onset epilepsy, it is expected that the number of patients with HCN1 mutations will grow steadily. Functional characterization of epilepsy-associated HCN1 mutations remains a fundamental tool for a better understanding of the pathogenetic mechanisms leading to the disease in humans.

EBioMedicine 72, 103588 (2021). doi:10.1016/j.ebiom.2021.103588, Published by Elsevier, Amsterdam [u.a.]

Summary Both mild and severe epilepsies are influenced by variants in the same genes, yet an explanation for the resulting phenotypic variation is unknown. As part of the ongoing Epi25 Collaboration, we performed a whole-exome sequencing analysis of 13,487 epilepsy-affected individuals and 15,678 control individuals. While prior Epi25 studies focused on gene-based collapsing analyses, we asked how the pattern of variation within genes differs by epilepsy type. Specifically, we compared the genetic architectures of severe developmental and epileptic encephalopathies (DEEs) and two generally less severe epilepsies, genetic generalized epilepsy and non-acquired focal epilepsy (NAFE). Our gene-based rare variant collapsing analysis used geographic ancestry-based clustering that included broader ancestries than previously possible and revealed novel associations. Using the missense intolerance ratio (MTR), we found that variants in DEE-affected individuals are in significantly more intolerant genic sub-regions than those in NAFE-affected individuals. Only previously reported pathogenic variants absent in available genomic datasets showed a significant burden in epilepsy-affected individuals compared with control individuals, and the ultra-rare pathogenic variants associated with DEE were located in more intolerant genic sub-regions than variants associated with non-DEE epilepsies. MTR filtering improved the yield of ultra-rare pathogenic variants in affected individuals compared with control individuals. Finally, analysis of variants in genes without a disease association revealed a significant burden of loss-of-function variants in the genes most intolerant to such variation, indicating additional epilepsy-risk genes yet to be discovered. Taken together, our study suggests that genic and sub-genic intolerance are critical characteristics for interpreting the effects of variation in genes that influence epilepsy.

The objective of this study was to identify developmental trajectories of developmental/behavioral phenotypes and possibly their relationship to epilepsy and genotype by analyzing developmental and behavioral features collected prospectively and longitudinally in a cohort of patients with Dravet syndrome (DS). Thirty-four patients from seven Italian tertiary pediatric neurology centers were enrolled in the study. All patients were examined for the SCN1A gene mutation and prospectively assessed from the first years of life with repeated full clinical observations including neurological and developmental examinations. Subjects were found to follow three neurodevelopmental trajectories. In the first group (16 patients), an initial and usually mild decline was observed between the second and the third year of life, specifically concerning visuomotor abilities, later progressing towards global involvement of all abilities. The second group (12 patients) showed an earlier onset of global developmental impairment, progressing towards a generally worse outcome. The third group of only two patients ended up with a normal neurodevelopmental quotient, but with behavioral and linguistic problems. The remaining four patients were not classifiable due to a lack of critical assessments just before developmental decline. The neurodevelopmental trajectories described in this study suggest a differential contribution of neurobiological and genetic factors. The profile of the first group, which included the largest fraction of patients, suggests that in the initial phase of the disease, visuomotor defects might play a major role in determining developmental decline. Early diagnosis of milder cases with initial visuomotor impairment may therefore provide new tools for a more accurate habilitation strategy.

De novo variants in KCNQ2 encoding for Kv7.2 voltage-dependent neuronal potassium (K+) channel subunits are associated with developmental epileptic encephalopathy (DEE). We herein describe a the clinical and electroencephalographic (EEG) features of a child with early-onset DEE caused by the novel KCNQ2 p.G310S variant. In vitro experiments demonstrated that the mutation induces loss-of-function effects on the currents produced by channels incorporating mutant subunits; these effects were counteracted by the selective Kv7 opener retigabine and by gabapentin, a recently described Kv7 activator. Given these data, the patient started treatment with gabapentin, showing a rapid and sustained clinical and EEG improvement over the following months. Overall, these results suggest that gabapentin can be regarded as a precision therapy for DEEs due to KCNQ2 loss-of-function mutations.

Purpose: Epilepsy is a main manifestation in the autosomal dominant mental retardation syndrome caused by heterozygous variants in MEF2C. We aimed to delineate the electro-clinical features and refine the genotype-phenotype correlations in patients with MEF2C haploinsufficiency. Methods: We thoroughly investigated 25 patients with genetically confirmed MEF2C-syndrome across 12 different European Genetics and Epilepsy Centers, focusing on the epileptic phenotype. Clinical features (seizure types, onset, evolution, and response to therapy), EEG recordings during waking/sleep, and neuroimaging findings were analyzed. We also performed a detailed literature review using the terms “MEF2C”, “seizures”, and “epilepsy”. Results: Epilepsy was diagnosed in 19 out of 25 (~80%) subjects, with age at onset

Objectives Pediatric catatonia is a rare and life-threatening syndrome. Around 20% of juvenile catatonia is associated with organic condition (Consoli et al., 2012). Autoimmune conditions represent a diagnostic and therapeutic challenge since specific antibodies can be missed. To facilitate decision making, we recently formulated a causality assessment score (CAUS) using a stepwise approach and an immunosuppressive therapeutic challenge (Ferrafiat et al., 2016). Our objectives were to validate retrospectively CAUS and to define its threshold for an accurate distinction between organic catatonia and non-organic catatonia, and specifically between autoimmune catatonia and non-organic catatonia. Method To obtain a sufficient number of cases with organic catatonia, we pooled two samples ( N = 104) – one from a child psychiatry center, the other from neuro-pediatrics center – expert in catatonia and autoimmune conditions. Organic conditions were diagnosed using a multidisciplinary approach and numerous paraclinical investigations. Given the binary classification needs, we used receiver operating characteristic (ROC) analysis (Peacock and Peacock, 2010) to calculate the best classification threshold. Results The cohort included 67 cases of non-organic catatonia and 37 cases of organic catatonia. ROC analysis showed that the CAUS performance in discriminating both organic catatonia vs. non-organic catatonia, and autoimmune catatonia vs. non-organic catatonia was excellent (Area Under the Curve = 0.99). In both analyses, for a CAUS threshold ≥ 5, accuracy equaled to 0.96. Conclusion Regarding juvenile catatonia, the use of the CAUS score algorithm combining a therapeutic challenge and a threshold ≥ 5 may help to diagnose and treat autoimmune conditions even without formal identification of auto-antibodies.

The presence of redundant copy number variants (CNVs) in groups of patients with neurological diseases suggests that these variants could have pathogenic effect. We have collected array comparative genomic hybridization (CGH) data of about 2,500 patients affected by neurocognitive disorders and we observed that CNVs in 2p16.3 locus were as frequent as those in 15q11.2, being both the most frequent unbalances in our cohort of patients. Focusing to 2p16.3 region, unbalances involving NRXN1 coding region have been already associated with neuropsychiatric disorders, although with incomplete penetrance, but little is known about CNVs located proximal to the gene, in the long noncoding RNA AK127244. We found that, in our cohort of patients with neuropsychiatric disorders, the frequency of CNVs involving AK127244 was comparable to that of NRXN1 gene. Patients carrying 2p16.3 unbalances shared some common clinical characteristics regardless NRXN1 and AK127244 CNVs localization, suggesting that the AK127244 long noncoding RNA could be involved in neurocognitive disease with the same effect of NRXN1 unbalances. AK127244 as well as NRXN1 unbalances seem to have a particular influence on language development, behavior or mood, according with the topographic correlation between NRXN1 expression and prefrontal cortex functions.

Anti-N-Methyl- d -aspartate-receptor (NMDAR) encephalitis is the most frequent autoimmune encephalitis in pediatric age. This retrospective observational study was aimed at describing the clinical characteristics of the disease in a cohort of children and teenagers. Eighteen patients (10 females and 8 males), with a median age of 12.4 years at symptom onset were enrolled. The clinical presentation of the disease was marked by neurological manifestations in 13 patients and by severe psychiatric and behavioral symptoms in 5. The symptoms at onset varied according to the age: all the children presented with prominent neurological symptoms, whereas psychiatric symptoms were prominent in teenagers. Regardless the age, movement disorders (MDs) were distinctive symptoms during the acute stage of the disease. Several MDs might coexist in a given patient, and persist during sleep. The complexity, and the oddness of MDs often challenged their definition and the differential diagnosis with psychiatric manifestations and epileptic seizures. Stereotyped motor phenomena were the most typical MDs, and were recorded in all patients. Among them, perseveration, reproduction of acquired complex motor activities, and orofacial dyskinesia were the most distinctive features. In children, hyperkinetic MDs dominate; in teenagers, by contrast, a constellation of symptoms consistent with catatonia was the most frequent syndrome observed. The management of the several symptoms requires their accurate recognition, definition and assessment, and the knowledge of the potential side effects of antiepileptic and psychotropic drugs which could either mimic or worsen symptoms of encephalitis.

Objective We aimed this study at identifying cortical areas involved in the generation of interictal spikes in Rasmussen’s Encephalitis (RE) patients using magnetoencephalography (MEG), at comparing spike localization with the degree of cortical atrophy detected by MRI, and at identifying short-term changes during the follow-up. Methods Five patients with RE underwent two MEG and magnetic resonance imaging (MRI) (six months interval). The sources of visually detected spikes were estimated using equivalent current dipoles technique; these were then superimposed on individual MRI and clustered; the locations of the clusters were related to the MRI stage of cortical atrophy. Results All patients showed spikes and clusters located in different cortical areas in both recordings; the locations had a limited correspondence with cortical atrophy. The second recordings showed changes in the localisation of spikes and clusters, and confirmed the dissimilarities with neuroradiological abnormalities. Conclusions The presence of clusters of spikes of variable localisation suggests that RE progresses in a multifocal and fluctuating manner. The cortical areas most involved in epileptogenesis did not completely coincide with the most atrophic areas. Significance MEG can contribute to evaluating multifocal hemispheric spikes in RE and to better understand the time course of epileptogenic process.

SummaryObjective To report the presurgical workup, surgical procedures, and outcomes in a series of pediatric patients with drug-resistant epilepsy involving the perisylvian/insular regions. Methods We retrospectively assessed 16 pediatric patients affected by drug-resistant focal epilepsy involving perisylvian/insular regions, who consecutively underwent tailored resective surgery. All patients underwent a detailed presurgical workup, which included the analysis of the anatomoelectroclinical correlations with scalp electroencephalography (EEG) and/or with stereo-electroencephalography (SEEG), brain magnetic resonance imaging (MRI), and comprehensive cognitive and neuropsychological evaluations. After surgery, all patients underwent serial clinical and laboratory evaluations. Results Focal motor seizures restricted to perioral area, associated with symptoms related to the surrounding areas (as auditory hallucinations, unpleasant paresthesia, fear, and epigastric sensation), characterized the ictal semiology in 75% of patients. In 50%, autonomic manifestations were present and in 56% subjective manifestations were reported. The 50% of the patients underwent SEEG with insular sampling to better define the epileptogenic zone. In all patients, the insular cortex was always part of the epileptogenic zone, and tailored resections also involved, with variable degree, the frontal, parietal, and temporal opercula. Preoperatively, the neuropsychological assessment revealed impairments in specific cognitive functions and mild or moderate cognitive compromise in 88% of the patients. Postoperatively, one patient had permanent slight hemiparesis. At the most recent follow-up (median 39 months), seizure outcome was satisfactory in 69% of patients: seven patients were completely seizure-free (Engel class Ia), two were free of disabling seizure (class Ic), and two had rare disabling seizures (class II). The cognitive functioning remained unchanged in 62%, and improved in 38%. Significance The assessment of perisylvian/insular epilepsy in children is particularly challenging. However, tailored resections based on a careful presurgical evaluation, including SEEG recording, may lead to a good seizure control and to a better overall outcome.

OBJECTIVE Dravet syndrome (DS) is a drug-resistant, infantile onset epilepsy syndrome with multiple seizure types and developmental delay. In recently published randomized controlled trials, fenfluramine (FFA) proved to be safe and effective in DS. METHODS DS patients were treated with FFA in the Zogenix Early Access Program at four Italian pediatric epilepsy centers. FFA was administered as add-on, twice daily at an initial dose of 0.2 mg/kg/d up to 0.7 mg/kg/d. Seizures were recorded in a diary. Adverse events and cardiac safety (with Doppler echocardiography) were investigated every 3 to 6 months. RESULTS Fifty-two patients were enrolled, with a median age of 8.6 years (interquartile range [IQR] = 4.1-13.9). Forty-five (86.5%) patients completed the efficacy analysis. The median follow-up was 9.0 months (IQR = 3.2-9.5). At last follow-up visit, there was a 77.4% median reduction in convulsive seizures. Thirty-two patients (71.1%) had a ≥50% reduction of convulsive seizures, 24 (53.3%) had a ≥75% reduction, and five (11.1%) were seizure-free. The most common adverse event was decreased appetite (n = 7, 13.4%). No echocardiographic signs of cardiac valvulopathy or pulmonary hypertension were observed. There was no correlation between type of genetic variants and response to FFA. SIGNIFICANCE In this real-world study, FFA provided a clinically meaningful reduction in convulsive seizure frequency in the majority of patients with DS and was well tolerated.

Objective To define the risks and consequences of cardiac abnormalities in ATP1A3-related syndromes. Methods Patients meeting clinical diagnostic criteria for rapid-onset dystonia-parkinsonism (RDP), alternating hemiplegia of childhood (AHC), and cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss (CAPOS) with ATP1A3 genetic analysis and at least 1 cardiac assessment were included. We evaluated the cardiac phenotype in an Atp1a3 knock-in mouse (Mashl+/−) to determine the sequence of events in seizure-related cardiac death. Results Ninety-eight patients with AHC, 9 with RDP, and 3 with CAPOS (63 female, mean age 17 years) were included. Resting ECG abnormalities were found in 52 of 87 (60%) with AHC, 2 of 3 (67%) with CAPOS, and 6 of 9 (67%) with RDP. Serial ECGs showed dynamic changes in 10 of 18 patients with AHC. The first Holter ECG was abnormal in 24 of 65 (37%) cases with AHC and RDP with either repolarization or conduction abnormalities. Echocardiography was normal. Cardiac intervention was required in 3 of 98 (≈3%) patients with AHC. In the mouse model, resting ECGs showed intracardiac conduction delay; during induced seizures, heart block or complete sinus arrest led to death. Conclusions We found increased prevalence of ECG dynamic abnormalities in all ATP1A3-related syndromes, with a risk of life-threatening cardiac rhythm abnormalities equivalent to that in established cardiac channelopathies (≈3%). Sudden cardiac death due to conduction abnormality emerged as a seizure-related outcome in murine Atp1a3-related disease. ATP1A3-related syndromes are cardiac diseases and neurologic diseases. We provide guidance to identify patients potentially at higher risk of sudden cardiac death who may benefit from insertion of a pacemaker or implantable cardioverter-defibrillator.

To describe the outcome of Dravet syndrome (DS) in adolescents and adults we conducted a longitudinal retrospective study of two independent cohorts of 34 adolescents (group 1) and 50 adults (group 2). In both cohorts, we collected information about genetic mutation, and semiology of seizures at onset and during disease course. At the last evaluation, we considered the following features: epilepsy (distinguishing myoclonic/complete and nonmyoclonic/incomplete phenotype), neurologic signs, intellectual disability (ID), and behavioral disorders. Moreover, in both cohorts, we performed a correlation analysis between early characteristics of the disease and the outcome of DS with regard to seizure persistence, ID, behavioral disorder, and neurologic impairment at last evaluation. Group 1 includes 22 adolescents with complete form of DS and 12 with incomplete form; group 2 includes 35 adults with complete form and 15 with incomplete form. The seizures persisted in 73.6% of adolescents and in 80% of adults, but epilepsy severity progressively decreased through age. Seizure persistence correlated with the complete phenotype and with the occurrence of reflex seizures. At last evaluation, ID was moderate or severe in 70.5% of adolescents and in 80% of adults. The most severe cognitive and motor impairment was observed in patients with persisting seizures. The severity of cognition, language, and neurologic impairment at last evaluation correlated statistically with the complete phenotype. The study confirms that the global outcome of DS is poor in most cases, albeit epilepsy severity decreases throughout adulthood. The improvement of epilepsy throughout ages is not associated with improvement in intellectual abilities and motor skills; this confirms that the unfavorable outcome is not a pure consequence of epilepsy.

Objectives The objective of this study was to investigate several clinical electroencephalogram (EEG) findings possibly predicting the early response to antiepileptic drugs (AEDs) and the late outcome in children with clinical EEG features fitting the syndromic diagnosis of childhood absence epilepsy (CAE). Methods In 117 untreated patients with typical absences, we analyzed clinical EEG features, and resting EEG activity using partial directed coherence to calculate out- and inflow of cortical oscillations in different regions of interest. Results Absences began before 4 years in 12.0%, at 4–9.5 years in 71.8%, and at 10–13 years in 16.2% of the cases. Valproate was started in 91 patients and ethosuximide in 27. With one of AEDs, 77.8% reached seizure control, while the remaining patients needed to switch to the alternative AED. Only 5.9% patients remained drug-resistant. Absences with simple automatisms were the only feature associated with a lack of response to the first AED. Connectivity analysis of resting EEGs showed increased frontal outflow in patients compared with controls, which was significantly greater in the nonresponders to the first AED than in responders. Among the 91 patients followed for 61.2 ± 31.7 months, 14.2% relapsed after a seizure-free period, without differences between the responders to the first or second AED. Conclusions The assessment of electroclinical features provided only minimal prognostic indices. The enhanced outflow of frontal oscillations suggests a circuitry dysfunction significantly greater in the nonresponder to the early treatment. Seizure relapses were rare and comparable in patients who reached seizure freedom with first or second AED, indicating that the resistance to one AED does not influence the outcome.

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.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 and13 years; and (3) written informed consent. Children were subdivided into three groups: ≤3 years,3 to 6 years, and6 years. Clinical, electroencephalography (EEG), neuroimaging, and neuropsychological variables were identified for statistical analyses.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 (p0.0001). 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.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.

Objective: To quantify gait abnormalities in people with Dravet syndrome (DS). Methods: Individuals with a confirmed diagnosis of DS were enrolled, and stratified according to knee flexion at initial contact (IC) and range of motion (ROM) during stance (atypical crouch: knee flexion >20° at IC and knee ROM >15° during stance; straight: knee flexion

The Hyperpolarization-activated Cyclic Nucleotide-gated (HCN) channels are highly expressed in the Central Nervous Systems, where they are responsible for the I h current. Together with specific accessory proteins, these channels finely regulate neuronal excitability and discharge activity. In the last few years, a substantial body of evidence has been gathered showing that modifications of I h can play an important role in the pathogenesis of epilepsy. However, the extent to which HCN dysfunction is spread among the epileptic population is still unknown. The aim of this work is to evaluate the impact of genetic mutations potentially affecting the HCN channels’ activity, using a NGS approach. We screened a large cohort of patients with epilepsy of unknown etiology for mutations in HCN1, HCN2 and HCN4 and in genes coding for accessory proteins (MiRP1, Filamin A, Caveolin-3, TRIP8b, Tamalin, S-SCAM and Mint2). We confirmed the presence of specific mutations of HCN genes affecting channel function and predisposing to the development of the disease. We also found several previously unreported additional genetic variants, whose contribution to the phenotype remains to be clarified. According to these results and data from literature, alteration of HCN1 channel function seems to play a major role in epilepsy, but also dysfunctional HCN2 and HCN4 channels can predispose to the development of the disease. Our findings suggest that inclusion of the genetic screening of HCN channels in diagnostic procedures of epileptic patients should be recommended. This would help pave the way for a better understanding of the role played by I h dysfunction in the pathogenesis of epilepsy.

Sequencing-based studies have identified novel risk genes for rare, severe epilepsies and revealed a role of rare deleterious variation in common epilepsies. To identify the shared and distinct ultra-rare genetic risk factors for rare and common epilepsies, we performed a whole-exome sequencing (WES) analysis of 9,170 epilepsy-affected individuals and 8,364 controls of European ancestry. We focused on three phenotypic groups; the rare but severe developmental and epileptic encephalopathies (DEE), and the commoner phenotypes of genetic generalized epilepsy (GGE) and non-acquired focal epilepsy (NAFE). We observed that compared to controls, individuals with any type of epilepsy carried an excess of ultra-rare, deleterious variants in constrained genes and in genes previously associated with epilepsy, with the strongest enrichment seen in DEE and the least in NAFE. Moreover, we found that inhibitory GABAA receptor genes were enriched for missense variants across all three classes of epilepsy, while no enrichment was seen in excitatory receptor genes. The larger gene groups for the GABAergic pathway or cation channels also showed a significant mutational burden in DEE and GGE. Although no single gene surpassed exome-wide significance among individuals with GGE or NAFE, highly constrained genes and genes encoding ion channels were among the top associations, including CACNA1G, EEF1A2, and GABRG2 for GGE and LGI1, TRIM3, and GABRG2 for NAFE. Our study confirms a convergence in the genetics of common and rare epilepsies associated with ultra-rare coding variation and highlights a ubiquitous role for GABAergic inhibition in epilepsy etiology in the largest epilepsy WES study to date.

Perampanel (PER) is a novel anti-seizure medication useful in different types of epilepsy. We intended to assess the effectiveness of PER on cortical myoclonus and seizure frequency in patients with progressive myoclonus epilepsy (PME), using quantitative validated scales. Forty-nine patients aged 36.6 ± 15.6 years with PME of various aetiology (18 EPM1, 12 EPM2, five with sialidosis, one with Kufs disease, one with EPM7, and 12 undetermined) were enrolled between January 2017 and June 2018. PER at the dose of 2–12 mg (5.3 ± 2.5) was added to existing therapy. Myoclonus severity was assessed using a minimal myoclonus scale (MMS) in all the patients before and after 4–6 months of steady PER dose, and by means of the Unified Myoclonus Rating Scale (UMRS) in 20 patients. Logistic regression analysis was used to identify the factors potentially predicting treatment efficacy. Four patients dropped out in the first two months due to psychiatric side effects. In the remaining patients, PER reduced myoclonus severity as assessed using MMS (Wilcoxon test: p < 0.001) and UMRS (p < 0.001), with the ‘Action myoclonus’ section of the UMRS showing the greatest improvement. The patients with EPM1 or EPM1-like phenotype were more likely to improve with PER (p = 0.011). Convulsive seizures which have recurred at least monthly in 17 patients were reduced by >50%. Side effects occurred in 22/49 (44.8%) patients, the most common being irritability followed by drowsiness. PER is effective in treating myoclonus and seizures in PME patients. The frequency of psychiatric side effects suggests the need for careful patient monitoring.

Glucose transporter type 1 deficiency syndrome (Glut1 DS) is a rare neurological disorder caused by impaired glucose delivery to the brain. The clinical spectrum of Glut1 DS mainly includes epilepsy, paroxysmal dyskinesia (PD), developmental delay and microcephaly. Glut1 DS diagnosis is based on the identification of hypoglycorrhachia and pathogenic mutations of the SLC2A1 gene. Here, we report the molecular screening of SLC2A1 in 354 patients clinically suspected for Glut1 DS. From this cohort, we selected 245 patients for whom comprehensive clinical and laboratory data were available. Among them, we identified 19 patients carrying nucleotide variants of pathological significance, 5 of which were novel. The symptoms of onset, which varied from neonatal to adult age, included epilepsy, PD or non-epileptic paroxysmal manifestations. The comparison of the clinical features between the 19 SLC2A1 mutated and the 226 non-mutated patients revealed that the onset of epilepsy within the first year of life (when associated with developmental delay or other neurological manifestations), the association of epilepsy with PD and acquired microcephaly are more common in mutated subjects. Taken together, these data confirm the variability of expression of the phenotypes associated with mutation of SLC2A1 and provide useful clinical tools for the early identification of subjects highly suspected for the disease.

International audience; Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels control neuronal excitability and their dysfunction has been linked to epileptogenesis but few individuals with neurological disorders related to variants altering HCN channels have been reported so far. In 2014, we described five individuals with epileptic encephalopathy due to de novo HCN1 variants. To delineate HCN1-related disorders and investigate genotype-phenotype correlations further, we assembled a cohort of 33 unpublished patients with novel pathogenic or likely pathogenic variants: 19 probands carrying 14 different de novo mutations and four families with dominantly inherited variants segregating with epilepsy in 14 individuals, but not penetrant in six additional individuals. Sporadic patients had epilepsy with median onset at age 7 months and in 36% the first seizure occurred during a febrile illness. Overall, considering familial and sporadic patients, the predominant phenotypes were mild, including genetic generalized epilepsies and genetic epilepsy with febrile seizures plus (GEFS+) spectrum. About 20% manifested neonatal/infantile onset otherwise unclassified epileptic encephalopathy. The study also included eight patients with variants of unknown significance: one adopted patient had two HCN1 variants, four probands had intellectual disability without seizures, and three individuals had missense variants inherited from an asymptomatic parent. Of the 18 novel pathogenic missense variants identified, 12 were associated with severe phenotypes and clustered within or close to transmembrane domains, while variants segregating with milder phenotypes were located outside transmembrane domains, in the intracellular N- and C-terminal parts of the channel. Five recurrent variants were associated with similar phenotypes. Using whole-cell patch-clamp, we showed that the impact of 12 selected variants ranged from complete loss-of-function to significant shifts in activation kinetics and/or voltage dependence. Functional analysis of three different substitutions altering Gly391 revealed that these variants had different consequences on channel biophysical properties. The Gly391Asp variant, associated with the most severe, neonatal phenotype, also had the most severe impact on channel function. Molecular dynamics simulation on channel structure showed that homotetramers were not conducting ions because the permeation path was blocked by cation(s) strongly complexed to the Asp residue, whereas heterotetramers showed an instantaneous current component possibly linked to deformation of the channel pore. In conclusion, our results considerably expand the clinical spectrum related to HCN1 variants to include common generalized epilepsy phenotypes and further illustrate how HCN1 has a pivotal function in brain development and control of neuronal excitability.

OBJECTIVES To determine the prevalence of epilepsy in children with early-onset mitochondrial diseases (MDs) and to evaluate the epileptic phenotypes and associated features. MATERIALS AND METHODS Children affected by MD with onset during the first year of life were enrolled. Patients were classified according to their mitochondrial phenotype, and all findings in patients with epilepsy versus patients without were compared. The epileptic features were analyzed. RESULTS The series includes 129 patients (70 females) with median age at disease onset of 3 months. The median time of follow-up was 5 years. Non-syndromic mitochondrial encephalopathy and pyruvate dehydrogenase complex deficiency were the main mitochondrial diseases associated with epilepsy (P

Background Paroxysmal Kinesigenic Dyskinesia (PKD, OMIM 128200) is the most common type of autosomal dominant Paroxysmal Dyskinesias characterized by attacks of dystonia and choreoathetosis triggered by sudden movements. Recently PRRT2, encoding proline-rich transmembrane protein 2, has been described as the most frequent causative gene for PKD. Methods We studied the incidence of PRRT2 mutations in a cohort of 16 PKD patients and their relatives for a total of 39 individuals. Results We identify mutations in 10/16 patients and 23 relatives. In 27/33 the mutation was the c.insC649 p.Arg217Profs*8. In 6 individuals from 3 families we found three new mutations: c.insT27 p.Ser9*, c.G967A p.Gly323Arg and c.delCA215_216 p.Thr72Argfs*62. Family history was positive in 9 patients. The mean age of onset was 10 years. Attacks lasted from a few seconds to 1 min and ranged from several per day to some per week, and were generalised in all patients. The main distinctive features of mutation-negative patients were the sporadic occurrence, the absence of association with epilepsy or EEG abnormalities and the poor response to Carbamazepine or other antiepileptic agents. Conclusions We report the first cohort of Italian patients mutated in PRRT2 and we confirm that this is the most frequent gene involved in PKD.

Electroencephalographic (EEG) photoparoxysmal response has been little investigated in very young patients. We studied 5055 patients aged less than 5 years with no acquired brain damage, who underwent EEG recording. We determined the prevalence and significance of photoparoxysmal response induced by 1 to 20 Hz photic stimulation. Fifty-three showed photoparoxysmal response and were diagnosed as having Dravet syndrome (11), epileptic encephalopathy with myoclonic seizures (8), neurodegenerative disorders (8), benign idiopathic epilepsies (9), and static disorders with a known or suspected genetic origin (17). Photoparoxysmal response occurred in response to 1 to 5 Hz trains in 41.5% subjects. In most patients with epileptic encephalopathies, photoparoxysmal response was a transient finding: in 53.2%, it failed to be replicated in the recordings performed more than 6 months after initial evaluation. Photoparoxysmal response is rare in patients aged less than 5 years and has some peculiarities such as occurrence with low-frequency stimuli. Its distribution in specific conditions indicates that photoparoxysmal response may be useful in diagnostic workup.

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.

Objective: To define the electroclinical phenotype and long-term outcomes in a cohort of patients with inv dup (15) syndrome. Material and Methods: The electroclinical data of 45 patients (25 males) affected by inv dup (15) and seizures were retrospectively analysed, and long-term follow-up of epilepsy was evaluated. Results: Epilepsy onset was marked by generalized seizures in 53% of patients, epileptic spasms in 51%, focal seizures in 26%, atypical absences in 11% and epileptic falls in 9%. The epileptic syndromes defined were: generalized epilepsy (26.7%), focal epilepsy (22.3%), epileptic encephalopathy with epileptic spasms as the only seizure type (17.7%) and Lennox-Gastaut syndrome (33.3%). Drug-resistant epilepsy was detected in 55.5% of patients. There was a significant higher prevalence of seizure-free patients in those with seizure onset after the age of 5 years and with focal epilepsy, with respect to those with earlier epilepsy onset because most of these later developed an epileptic encephalopathy (69.2% vs 34.4%; P = .03), usually Lennox-Gastaut Syndrome in type. In fact, among patients with early-onset epilepsy, those presenting with epileptic spasms as the only seizure type associated with classical hypsarrhythmia achieved seizure freedom (P < .001) compared to patients with spasms and other seizure types associated with modified hypsarrhythmia. Conclusions: Epilepsy in inv dup (15) leads to a more severe burden of disease. Frequently, these patients show drug resistance, in particular when epilepsy onset is before the age of five and features epileptic encephalopathy.

Objectivies Monosomy 1p36 syndrome is a recognized syndrome with multiple congenital anomalies; medical problems of this syndrome include developmental delay, facial dysmorphisms, hearing loss, short stature, brain anomalies, congenital heart defects. Epilepsy can be another feature but there are few data about the types of seizures and long term prognosis. The aim of this work was to analyse the electroclinical phenotype and the long-term outcome in patients with monosomy 1p36 syndrome and epilepsy. Materials and methods Data of 22 patients with monosomy 1p36 syndrome and epilepsy were reconstructed by reviewing medical records. For each patient we analysed age at time of diagnosis, first signs of the syndrome, age at seizure onset, seizure type and its frequency, EEG and neuroimaging findings, the response to antiepileptic drugs treatment and clinical outcome up to the last follow-up assessment. Results Infantile Spasm (IS) represents the most frequent type at epilepsy onset, which occurs in 36.4% of children, and a half of these were associated with hypsarrhythmic electroencephalogram. All patients with IS had persistence of seizures, unlike other patients with different seizures onset. Children with abnormal brain neuroimaging have a greater chance to develop pharmacoresistant epilepsy. Conclusion This syndrome represents a significant cause of IS: these patients, who develop IS, can suffer from pharmacoresistent epilepsy, that is more frequent in children with brain abnormalities.

Over one hundred mutations in the Kv7.2 (KCNQ2) gene encoding for phosphatidylinositol 4,5-bisphosphate (PIP2)-sensitive voltage-gated K+ channel subunits have been identified in early-onset epilepsies with wide phenotypic variability. By contrast, only few mutations in the closely related Kv7.3 (KCNQ3) gene have been reported, mostly associated with typical benign familial neonatal seizures (BFNS). We herein describe a patient affected by early onset epileptic encephalopathy (EOEE) carrying two Kv7.3 missense mutations (p.Val359Leu/V359L and p.Asp542Asn/D542N) in compound heterozygosis, each inherited from an asymptomatic parent. Patch-clamp recordings from transiently transfected CHO cells showed that, when incorporated in physiologically relevant Kv7.2 + Kv7.3 heteromeric channels, expression of Kv7.3 V359L or Kv7.3 D542N subunits failed to affect current density, whereas a significant decrease was instead observed when these mutant subunits were both simultaneously present. Modeling and functional experiments revealed that each variant decreased PIP2-dependent current regulation, with additive effects when the two were co-expressed. Moreover, expression of Kv7.2 subunits carrying the D535N variant previously described in three sporadic EOEE cases prompted functional changes more dramatic when compared to those of the corresponding D542N variant in Kv7.3, but similar to those observed when both Kv7.3 V359L and Kv7.3 D542N subunits were expressed together. Finally, the Kv7 activator retigabine restored channel dysfunction induced by each Kv7.2 or Kv7.3 variant(s). These results provide a plausible molecular explanation for the apparent recessive inheritance of the phenotype in the family investigated, and a rational basis for personalized therapy with Kv7 channel activators in EOEE patients carrying loss-of-function mutations in Kv7.2 or Kv7.3.

Over one hundred mutations in the Kv7.2 (KCNQ2) gene encoding for phosphatidylinositol 4,5-bisphosphate (PIP

By way of whole-exome sequencing, we identified a homozygous missense mutation in VARS2 in one subject with microcephaly and epilepsy associated with isolated deficiency of the mitochondrial respiratory chain (MRC) complex I and compound heterozygous mutations in TARS2 in two siblings presenting with axial hypotonia and severe psychomotor delay associated with multiple MRC defects. The nucleotide variants segregated within the families, were absent in Single Nucleotide Polymorphism (SNP) databases and are predicted to be deleterious. The amount of VARS2 and TARS2 proteins and valyl-tRNA and threonyl-tRNA levels were decreased in samples of afflicted patients according to the genetic defect. Expression of the corresponding wild-type transcripts in immortalized mutant fibroblasts rescued the biochemical impairment of mitochondrial respiration and yeast modeling of the VARS2 mutation confirmed its pathogenic role. Taken together, these data demonstrate the role of the identified mutations for these mitochondriopathies. Our study reports the first mutations in the VARS2 and TARS2 genes, which encode two mitochondrial aminoacyl-tRNA synthetases, as causes of clinically distinct, early-onset mitochondrial encephalopathies.

Objective:To explore the prognostic value of initial clinical and mutational findings in infants with SCN1A mutations.Methods:Combining sex, age/fever at first seizure, family history of epilepsy, EEG, and mutation type, we analyzed the accuracy of significant associations in predicting Dravet syndrome vs milder outcomes in 182 mutation carriers ascertained after seizure onset. To assess the diagnostic accuracy of all parameters, we calculated sensitivity, specificity, receiver operating characteristic (ROC) curves, diagnostic odds ratios, and positive and negative predictive values and the accuracy of combined information. We also included in the study demographic and mutational data of the healthy relatives of mutation carrier patients.Results:Ninety-seven individuals (48.5%) had Dravet syndrome, 49 (23.8%) had generalized/genetic epilepsy with febrile seizures plus, 30 (14.8%) had febrile seizures, 6 (3.5%) had focal epilepsy, and 18 (8.9%) were healthy relatives. The association study indicated that age at first seizure and frameshift mutations were associated with Dravet syndrome. The risk of Dravet syndrome was 85% in the 0- to 6-month group, 51% in the 6- to 12-month range, and 0% after the 12th month. ROC analysis identified onset within the sixth month as the diagnostic cutoff for progression to Dravet syndrome (sensitivity = 83.3%, specificity = 76.6%).Conclusions:In individuals with SCN1A mutations, age at seizure onset appears to predict outcome better than mutation type. Because outcome is not predetermined by genetic factors only, early recognition and treatment that mitigates prolonged/repeated seizures in the first year of life might also limit the progression to epileptic encephalopathy.

Objective:To explore the course of Unverricht-Lundborg disease (EPM1) and identify the risk factors for severity, we investigated the time course of symptoms and prognostic factors already detectable near to disease onset.Methods:We retrospectively evaluated the features of 59 Italian patients carrying the CSTB expansion mutation, and coded the information every 5 years after the disease onset in order to describe the cumulative time-dependent probability of reaching disabling myoclonus, relevant cognitive impairment, and inability to work, and evaluated the influence of early factors using the log-rank test. The risk factors were included in a Cox multivariate proportional hazards regression model.Results:Disabling myoclonus occurred an average of 32 years after disease onset, whereas cognitive impairment occurred a little later. An age at onset of less than 12 years, the severity of myoclonus at the time of first assessment, and seizure persistence more than 10 years after onset affected the timing of disabling myoclonus and cognitive decline. Most patients became unable to work years before the appearance of disabling myoclonus or cognitive decline.Conclusions:A younger age at onset, early severe myoclonus, and seizure persistence are predictors of a more severe outcome. All of these factors may be genetically determined, but the greater hyperexcitability underlying more severe seizures and myoclonus at onset may also play a role by increasing cell damage due to reduced cystatin B activity.

Mutations in the TBC1D24 gene (MIM 613577) cause familial infantile myoclonic epilepsy (FIME; 605021) and early infantile epileptic encephalopathy-16 (EIEE16; 615338), both inherited with an autosomal recessive trait. The TBC1D24 gene encodes a member of the TBC family domain proteins, involved in cell signaling and oxidative stress resistance. We studied, by a Next Generation Sequencing (NGS) target re-sequencing gene approach, the DNA of a 5 year-old girl, affected by recurrent attacks of Alternating Hemiplegia (AH) and by recurrent episodes of Epilepsia Partialis Continua (EPC). The NGS study showed the presence of two different heterozygous, probably pathogenic variants in the TBC1D24 gene, inherited in trans from her parents: the c.116C>T (p.Ala39Val) and the c.457G>A (p.Glu153Lys). This study describes for the first time the association between TBC1D24 variants and AH expanding the phenotypic spectrum of TBC1D24-related diseases and suggesting that TBC1D24 molecular analysis should be considered in the diagnostic work up of AH patients. An additional peculiar feature is the association of AH and EPC.