Early predictors of remission in children and adolescents with new-onset epilepsy: A prospective study.

PURPOSE: This study aims to identify predictive factors of a two-year remission (2YR) in a cohort of children and adolescents with new-onset seizures based on baseline clinical characteristics, initial EEG and brain MRI findings. METHODS: A prospective cohort of 688 patients with new onset seizures, initiated on treatment with antiseizure medication was evaluated. 2YR was defined as achieving at least two years of seizure freedom during the follow-up period. Multivariable analysis was performed and recursive partition analysis was utilized to develop a decision tree. RESULTS: The median age at seizure onset was 6.7 years, and the median follow-up was 7.4 years. 548 (79.7%) patients achieved a 2YR during the follow up period. Multivariable analysis found that presence and degree of intellectual and developmental delay (IDD), epileptogenic lesion on brain MRI and a higher number of pretreatment seizures were significantly associated with a lower probability of achieving a 2YR. Recursive partition analysis showed that the absence of IDD was the most important predictor of remission. An epileptogenic lesion was a significant predictor of non-remission only in patients without evidence of IDD, and a high number of pretreatment seizures was a predictive factor in children without IDD and in the absence of an epileptogenic lesion. CONCLUSION: Our results indicate that it is possible to identify patients at risk of not achieving a 2YR based on variables obtained at the initial evaluation. This could allow for a timely selection of patients who require close follow-up, consideration for neurosurgical intervention, or investigational treatments trials.

PI4K2A deficiency causes innate error in intracellular trafficking with developmental and epileptic-dyskinetic encephalopathy.

OBJECTIVE: Intracellular signaling networks rely on proper membrane organization to control an array of cellular processes such as metabolism, proliferation, apoptosis, and macroautophagy in eukaryotic cells and organisms. Phosphatidylinositol 4-phosphate (PI4P) emerged as an essential regulatory lipid within organelle membranes that defines their lipid composition and signaling properties. PI4P is generated by four distinct phosphatidylinositol 4-kinases (PI4K) in mammalian cells: PI4KA, PI4KB, PI4K2A, PI4K2B. Animal models and human genetic studies suggest vital roles of PI4K enzymes in development and function of various organs, including the nervous system. Bi-allelic variants in PI4KA were recently associated with neurodevelopmental disorders (NDD), brain malformations, leukodystrophy, primary immunodeficiency, and inflammatory bowel disease. Here, we describe patients from two unrelated consanguineous families with PI4K2A deficiency and functionally explored the pathogenic mechanism. METHODS: Two patients with PI4K2A deficiency were identified by exome sequencing, presenting with developmental and epileptic-dyskinetic encephalopathy. Neuroimaging showed corpus callosum dysgenesis, diffuse white matter volume loss, and hypoplastic vermis. In addition to NDD, we observed recurrent infections and death at toddler age. We further explored identified variants with cellular assays. RESULTS: This clinical presentation overlaps with what was previously reported in two affected siblings with homozygous nonsense PI4K2A variant. Cellular studies analyzing these human variants confirmed their deleterious effect on PI4K2A activity and, together with the central role of PI4K2A in Rab7-associated vesicular trafficking, establish a link between late endosome-lysosome defects and NDD. INTERPRETATION: Our study establishes the genotype-phenotype spectrum of PI4K-associated NDD and highlights several commonalities with other innate errors of intracellular trafficking.

Early infantile epileptic encephalopathy related to NECAP1: Clinical delineation of the disease and review.

BACKGROUND AND PURPOSE: Epileptic encephalopathy (EE) refers to a heterogeneous group of epilepsy syndromes characterized by seizures as well as encephalopathies, leading to cognitive and behavioral disturbances. These conditions vary in their age at onset, their severity, and their electroencephalographic patterns. Whereas genetic factors are involved in approximately 40% of all epilepsy cases, they contribute to 80% of early infantile EEs (EIEEs), with approximately 125 genes previously linked to this disease. METHODS: Whole exome sequencing (WES) was performed in a 9-month-old Lebanese girl presenting with EIEE. RESULTS: WES enabled the detection of a homozygous missense mutation in the NECAP1 gene (NM_015509.3: p.Glu8Lys) in the proband. CONCLUSIONS: Here, we report the first homozygous missense mutation in the NECAP1 gene in a 9-month-old girl presenting with EIEE. Our findings allow a better characterization of the NECAP1-linked disease and enable broadening its clinical spectrum by including, in addition to EIEE, severe generalized hypotonia, poor feeding, developmental delay, severe microcephaly, delayed myelination, abnormalities of the corpus callosum, and eye abnormalities.

A 20-year Clinical and Genetic Neuromuscular Cohort Analysis in Lebanon: An International Effort.

BACKGROUND: Clinical and molecular data on the occurrence and frequency of inherited neuromuscular disorders (NMD) in the Lebanese population is scarce. OBJECTIVE: This study aims to provide a retrospective overview of hereditary NMDs based on our clinical consultations in Lebanon. METHODS: Clinical and molecular data of patients referred to a multi-disciplinary consultation for neuromuscular disorders over a 20-year period (1999-2019) was reviewed. RESULTS: A total of 506 patients were diagnosed with 62 different disorders encompassing 10 classes of NMDs. 103 variants in 49 genes were identified. In this cohort, 81.4% of patients were diagnosed with motor neuron diseases and muscular dystrophies, with almost half of these described with spinal muscular atrophy (SMA) (40.3% of patients). We estimate a high SMA incidence of 1 in 7,500 births in Lebanon. Duchenne and Becker muscular dystrophy were the second most frequently diagnosed NMDs (17% of patients). These disorders were associated with the highest number of variants (39) identified in this study. A highly heterogeneous presentation of Limb Girdle Muscular Dystrophy and Charcot-Marie-Tooth disease was notably identified. The least common disorders (5.5% of patients) involved congenital, metabolic, and mitochondrial myopathies, congenital myasthenic syndromes, and myotonic dystrophies. A review of the literature for selected NMDs in Lebanon is provided. CONCLUSIONS: Our study indicates a high prevalence and underreporting of heterogeneous forms of NMDs in Lebanon- a major challenge with many novel NMD treatments in the pipeline. This report calls for a regional NMD patient registry.

The importance of acknowledging diagnostic uncertainty in patients with new-onset paroxysmal spells.

OBJECTIVE: The aims of this study were to evaluate the frequency of paroxysmal spells of indeterminate nature (PSIN) in a large cohort of children and adults with suspected new-onset seizures, to evaluate the reasons for including patients in this category, and to calculate the rate of erroneous diagnoses if the epileptologists were compelled to label those events as epileptic seizures or nonepileptic paroxysmal spells. METHODS: Patients identified for this study participated in a prospective study evaluating patients with suspected new-onset unprovoked seizures. The workup included a detailed history and a thorough description of the spells, a 3-hour video EEG recording, and an epilepsy protocol brain MRI. Based exclusively on a detailed description of the ictal events, two epileptologists were asked to independently classify each patient into those with a definite diagnosis of unprovoked seizures or a definite diagnosis of a nonepileptic paroxysmal spells (group 1) and those with PSIN (group 2). RESULTS: A total of 1880 consecutive patients were enrolled with 255 (13.6%) included in the PSIN group. Patients with PSIN were significantly younger than those with a definite diagnosis, and PSIN were significantly more frequent in children with developmental delay. The most common reason for including patients in the PSIN group was the inability to categorically discriminate between a seizure and a nonepileptic mimicker. When the raters were compelled to classify the spells in the PSIN group, the frequencies of erroneous diagnoses ranged between 32% and 38%. The final diagnoses on those patients were made based on the results of the EEG, MRI, and follow-up visits. SIGNIFICANCE: Our data indicate that a diagnostic category of PSIN should be recognized and ought to be used in clinical practice. Acknowledging this uncertainty will result in lower frequencies of erroneous diagnoses, possible stigma, and potential exposure to unnecessary antiseizure medications.

Efficacy and tolerability of treatment with lacosamide in children: Postmarketing experience from the Middle East.

PURPOSE: The aim of this study was to evaluate the tolerability and efficacy of lacosamide (LCM) in Lebanese children with focal-onset seizures and to determine if specific variables are predictive of better effectiveness. METHODS: This is a retrospective analysis from three medical centers on consecutive children diagnosed with focal onset seizures and initiated on LCM. The seizure frequencies following the introduction of LCM were recorded and compared to the baseline monthly frequency at 3, 6, 12, 18, and 24 months. The primary efficacy variables were the 50% responder and seizure-free rates. The secondary outcome variables included the terminal 6-month seizure remission and percentages of discontinuation due to lack of efficacy or tolerability. RESULTS: 58 patients with a mean age of 10 years experiencing a mean of 36.2 seizures per month during baseline were included. The seizure-free rates were 32.8%, 29.7%, and 12.5% at 6, 12 and 24 months follow up, respectively. Patients concomitantly treated with a sodium channel blocker were less likely to achieve a terminal 6-month seizure remission while the early introduction of LCM resulted in a significantly higher likelihood of attaining such a remission. 74.1% of patients were still maintained on LCM at the last follow-up. The most common adverse events consisted of dizziness, somnolence, nausea, vomiting, and rarely double vision. CONCLUSIONS: LCM is efficacious and overall well tolerated in children with focal-onset seizures and exhibits higher efficacy with early introduction and when added to a non-sodium channel blocker.

CNTNAP1 Mutations and Their Clinical Presentations: New Case Report and Systematic Review.

Lethal congenital contracture syndrome type 7 (LCCS7) and congenital hypomyelinating neuropathy type 3 (CHN3) are rare autosomal recessive diseases, characterized by severe neonatal hypotonia, polyhydramnios, arthrogryposis, facial diplegia, and severe motor paralysis, leading to death in early infancy. They are related to mutations in the CNTNAP1 (contactin associated protein 1) gene, playing an important role in myelination. Recent studies have shown that both diseases could present with a wide phenotypic spectrum, with promising survival up to early childhood. We report on a 7-year-old boy from a nonconsanguineous Lebanese family presenting with neonatal hypotonia, respiratory distress, and arthrogryposis. Molecular analysis revealed the presence of a pathogenic variant in the CNTNAP1 gene leading to a premature stop codon: NM_003632.2:c.3361C>T p.(Arg1121 ∗ ). A review of the literature is discussed.

Hyperventilation-induced high-amplitude rhythmic slowing: A mimicker of absence seizures in children.

PURPOSE: Hyperventilation (HV) in children can lead to HV-induced high-amplitude rhythmic slowing (HIHARS) on the EEG (electroencephalogram) which is sometimes associated with altered awareness (AA) and concomitant semiological features. Our aims were to determine the frequency of HIHARS in children, to assess if the associated semiological features were temporally related to HV, and to evaluate if specific semiological features can differentiate HIHARS with AA from absence seizures. METHODS: Consecutive children with suspected new onset seizure(s) underwent HV and awareness testing during video-EEG acquisition. Hyperventilation-induced high-amplitude rhythmic slowing was defined as 2.5- to 5-Hz generalized rhythmic slowing with amplitude ≥100 µv lasting for ≥3 s. The associated semiological features were compared between the group of children with HIHARS and AA, an age- and gender-matched control group without HIHARS, and in children who experienced absence seizures during HV. RESULTS: One hundred sixteen children with a mean age of 9.8 years were included. Hyperventilation-induced high-amplitude rhythmic slowing occurred in 39 children (33.6%) with AA documented in 30 (76.9%). The probability of developing AA during HIHARS was significantly and positively correlated with the HIHARS duration. The frequencies of HIHARS were not significantly different between children diagnosed with seizure(s) and those with nonepileptic spells. Hyperventilation cessation and staring did not occur in any child of the control group. Fidgeting and yawning were significantly more common in the group with HIHARS with AA while staring and blinking were significantly more frequent in the group of children with absence seizures. CONCLUSIONS: We ascertained that HIHARS with AA is a relatively common occurrence in children and most likely represents an age-related nonepileptic phenomenon. When associated with fidgeting or yawning, it can help differentiate this phenomenon from absence seizures. However, recording the concomitant presence of generalized spike wave discharges on the EEG remains essential to confirm the diagnosis of absence seizures.

Further Delineation of the TRAPPC6B Disorder: Report on a New Family and Review.

Pathogenic variants in the TRAPPC6B gene were recently found to be associated in three consanguineous families, with microcephaly, epilepsy, and brain malformations. Here, we report on a 3.5-year-old boy, born to consanguineous Lebanese parents, who presented with developmental delay, lactic acidosis, postnatal microcephaly, and abnormal brain magnetic resonance imaging. By whole exome sequencing, a novel homozygous likely pathogenic variant in exon 1 of the TRAPPC6B gene (c.23T > A; [p.Leu8*]) was identified. A review of the clinical description and literature is discussed, pointing out the phenotypic heterogeneity associated with mutations in this gene.

Report of a Second Lebanese Family with Basel-Vanagaite-Smirin-Yosef Syndrome: Possible Founder Mutation.

Basel-Vanagaite-Smirin-Yosef syndrome (OMIM 616449) is a rare autosomal recessive genetic disorder characterized by severe developmental delay and variable craniofacial, neurological, cardiac, and ocular anomalies in the presence of variants in the MED25 gene. So far, only a handful of patients have been reported with this condition globally. Here, we report an additional Lebanese family with 2 affected siblings presenting with severely delayed psychomotor and language development as well as craniofacial anomalies. By whole-exome sequencing (WES), a homozygous variant was found in the MED25 gene, c.518T>C, predicted to result in a p.Ile173Thr change in the MED25 protein. This change has recently been reported in another Lebanese family. Review of the literature, the importance of this mutation in the Lebanese population, and the possibility that this condition may be underdiagnosed and only effectively detected using molecular techniques such as WES are discussed.

The Lebanese Allele in the PET100 Gene: Report on Two New Families with Cytochrome c Oxidase Deficiency.

Cytochrome c oxidase deficiency is caused by mutations in any of at least 30 mitochondrial and nuclear genes involved in mitochondrial complex IV biogenesis and structure, including the recently identified PET100 gene. Here, we report two families, of which one is consanguineous, with two affected siblings each. In one family, the siblings presented with developmental delay, seizures, lactic acidosis, abnormal brain magnetic resonance imaging, and low muscle mitochondrial complex IV activity at 30%. In the other family, the two siblings, now deceased, had a history of global developmental delay, failure to thrive, muscular hypotonia, seizures, developmental regression, respiratory insufficiency, and lactic acidosis. By whole exome sequencing, a missense mutation in exon 1 of the PET100 gene (c.3G > C; [p.Met1?]) was identified in both families. A review of the clinical description and literature is discussed, highlighting the importance of this variant in the Lebanese population.

Dravet Syndrome in Lebanon: First Report on Cases with SCN1A Mutations.

Dravet syndrome, also known as severe myoclonic epilepsy in infancy, is a rare disease characterized by the appearance of different types of seizures in a healthy baby, triggered by various factors and stressful events. We report 8 Lebanese cases referred for molecular analysis of the SCN1A gene. Results were positive in 7 cases and revealed de novo variants at the heterozygous state in different exons of the gene for all except one, where the variant was intronic. Four variants were novel. Confirmation of Dravet syndrome is important for a better follow-up and treatment, preventing the occurrence of status epilepticus and severe neurological deterioration.

Contribution of next generation sequencing in pediatric practice in Lebanon. A Study on 213 cases.

BACKGROUND: According to the Catalogue of Transmission Genetics in Arabs, less than half of diseases reported in Lebanese patients are mapped. In the recent years, Next Generation Sequencing (NGS) techniques have significantly improved clinical diagnosis, compared to traditional sequencing methods. METHODS: A total of 213 analyses by NGS (167 by whole exome sequencing (WES) and 46 by multigene panels tests) were performed on pediatric patients across different regions of Lebanon over a period of two years (December 2015-December 2017). RESULTS: Neurological disorders were the most frequent referral demand for both WES and gene panels (122/213). Pathogenic, likely pathogenic, or variants of unknown significance were identified in 69.5% of the WES and panel patients combined. Over half of the patients with such variants had an autosomal recessive disorder. A definite molecular diagnosis (pathogenic or likely pathogenic variants) was achieved in 34.1% and 47.8% of the patients studied by WES and the multigene panels, respectively. Thirty-three novel variants were found in the cases that were molecularly solved; 26 of these being identified by WES and seven by the multigene panels. In three consanguineous families, autosomal recessive inheritance of genes previously reported as showing dominant inheritance patterns were found. Biallelism was found in six cases, digenism in four cases, and one case was trigenic. CONCLUSION: Our study thus suggests that NGS tools are valuable for an improved clinical diagnosis, and highlights that the increased adoption of such techniques will significantly further improve our understanding of the genetic basis of inherited diseases in Lebanon.

Contribution of copy number variants (CNVs) to congenital, unexplained intellectual and developmental disabilities in Lebanese patients.

BACKGROUND: Chromosomal microarray analysis (CMA) is currently the most widely adopted clinical test for patients with unexplained intellectual disability (ID), developmental delay (DD), and congenital anomalies. Its use has revealed the capacity to detect copy number variants (CNVs), as well as regions of homozygosity, that, based on their distribution on chromosomes, indicate uniparental disomy or parental consanguinity that is suggestive of an increased probability of recessive disease. RESULTS: We screened 149 Lebanese probands with ID/DD and 99 healthy controls using the Affymetrix Cyto 2.7 M and SNP6.0 arrays. We report all identified CNVs, which we divided into groups. Pathogenic CNVs were identified in 12.1% of the patients. We review the genotype/phenotype correlation in a patient with a 1q44 microdeletion and refine the minimal critical regions responsible for the 10q26 and 16q monosomy syndromes. Several likely causative CNVs were also detected, including new homozygous microdeletions (9p23p24.1, 10q25.2, and 8p23.1) in 3 patients born to consanguineous parents, involving potential candidate genes. However, the clinical interpretation of several other CNVs remains uncertain, including a microdeletion affecting ATRNL1. This CNV of unknown significance was inherited from the patient's unaffected-mother; therefore, additional ethnically matched controls must be screened to obtain enough evidence for classification of this CNV. CONCLUSION: This study has provided supporting evidence that whole-genome analysis is a powerful method for uncovering chromosomal imbalances, regardless of consanguinity in the parents of patients and despite the challenge presented by analyzing some CNVs.

Valproate-induced enuresis: a prospective study.

AIM: The aim of this study was to determine the frequency and characteristics of secondary enuresis in children initiated on valproate treatment. METHOD: This was a prospective study conducted in children aged 5 to 12 years with suspected newly diagnosed epilepsy and maintained on valproate for at least 1 month. Adverse events spontaneously reported by parents were recorded at each follow-up visit. In addition, we specifically asked about enuresis and other side effects known to occur with valproate treatment. We assessed the frequency of enuresis and its association with a number of variables. RESULTS: Seventy-two children (43 males and 29 females) with a mean age of 8 years 7 months (range 5-12y) were included in this study. Secondary enuresis developed in 17 (24%) of these children after, on average, 19.8 days of exposure to valproate. The data obtained from a multivariate analysis indicate that age was the only significant factor in predicting the development of enuresis. Enuresis ceased in all children after discontinuation of valproate use, and in 10 out of 11 children still on the drug. INTERPRETATION: Secondary enuresis is a common adverse event associated with valproate use in children, which is not usually spontaneously reported and is reversible in most cases.

Homozygous stop mutation in the SNX10 gene in a consanguineous Iraqi boy with osteopetrosis and corpus callosum hypoplasia.

Recently a mutation in the SNX10 gene that belongs to the sorting nexin family was identified as a cause of a new subset of human autosomal recessive osteopetrosis. Here, we identified a novel homozygous mutation (c.46C > T, p.Arg16X) in SNX10, in an Iraqi boy from a consanguineous family with a history of infantile osteopetrosis. The proband exhibited macrocephaly, prominent forehead, proptosis of the eyes, strabismus, splenomegaly and joint hyperlaxity. Bone X-rays showed increased bone density, metaphyseal under-modelling, transverse alternating bands of greater and lesser density in tubular bones, anteriorly notched vertebral bodies and bone-in-bone appearance. Brain atrophy, external hydrocephalus and thin corpus callosum were noted at the brain MRI and CT scan. Blood test results revealed the presence of anaemia and leukopenia. Our findings confirm the role of SNX10 in autosomal recessive osteopetrosis and help to better define the core set of manifestations associated with this new pathological entity.

Behavioral problems, cognitive difficulties and quality of life in children with epilepsy: an analysis of parental concerns.

In cognitively impaired or young children with epilepsy, only proxy-report can be used for the assessment of Quality of Life (QOL) and behavior. The present study aims to propose proxy QOL tools applicable in all children with epilepsy and to examine the impact of epilepsy characteristics (e.g., age of onset of epilepsy, epilepsy syndrome) and child's age and situation (in mainstream school or in special institution). We studied 219 children with various types of epilepsy with and without cognitive impairment. The study adapted published QOL scales and used a new parental QOL questionnaire. Selected items concerned 6 "domains" of QOL: global QOL, illness impact, depression/anxiety, hyperactivity/disrupting behavior, sociability, and parental QOL. School situation, epilepsy syndrome, and age were significantly and differentially related to the QOL domains. The proposed QOL tools are applicable to all children with epilepsy independently of comorbid conditions and can be used in a clinical context and for research studies of QOL in children with epilepsy. Epilepsy syndromes in children and their associated factors have a crucial impact on parental concerns and QOL.

Ambiguous genitalia, microcephaly, seizures, bone malformations, and early death: a distinct MCA/MR syndrome.

We report on two siblings with hypotonia, ambiguous genitalia, microcephaly, ptosis, microretrognathia, thin lips, seizures, absent ossification of pubic rami, and brain abnormalities at the MRI. The two siblings died at 5 and 8 months, respectively. Molecular analysis indicated that SOX9, ARX, and DHCR7 genes were normal. Comparative genomic hybridization (CGH)-array analysis performed on the younger boy indicated two notable deletions, one on paternally inherited chromosome 4, and one on maternally inherited chromosome 5. The same deletions were found in a normal sister. Differential diagnoses and the possibility of a hitherto unreported syndrome are discussed.

Epileptic phenotypes in children with respiratory chain disorders.

PURPOSE: Epilepsy is a commonly reported but rarely described clinical hallmark of mitochondrial respiratory chain defects (RCDs) with encephalopathy. METHODS: From 1990-2006 we collected data about 56 children with RCD (single, n = 24 or multiple, n = 20 mitochondrial complex deficiencies; mtDNA mutation, n = 11; mtDNA depletion n = 10 of 21; and nuclear gene mutation n = 11). Epileptic features were reviewed retrospectively. RESULTS: First seizures were frequently (47 patients, 82.5%) preceded by failure to thrive, psychomotor delay, ataxia, or multisystemic dysfunction. Sixty percent of the patients had several seizure types. Six age-related epilepsy phenotypes could be identified: status epilepticus complicating neonatal multivisceral deficiency (2 patients), neonatal myoclonic encephalopathy (3 patients), infantile spasms (8 patients), refractory or recurrent status epilepticus (21 patients), epilepsia partialis continua (4 patients), and myoclonic epilepsy (18 patients). Except for infantile spasms, epilepsy was difficult to control in most patients (95%). Valproate was administered to 25 patients, one of whom developed acute liver failure 6 days later. Twenty-two patients (45%) died, half of them within 9 months from the onset of epilepsy. DISCUSSION: In RCD, epilepsy is not only difficult to control but its occurrence often indicates a severe turn in the course of the disease. For one-third of the patients, classical biochemical measures failed to reveal any abnormality and RCD could be detected in the liver only.

Parental report of cognitive difficulties, quality of life and rehabilitation in children with epilepsy or treated for brain tumour.

PURPOSE: Paediatric neurological chronic conditions are often associated with physical, cognitive, psychological and behavioural difficulties that may affect quality of life (QOL) of children and their families. In this study, we compare parental report of difficulties and rehabilitation in children with various epileptic syndromes or treated for a benign or malignant brain tumour. METHOD: One hundred fifty-three children aged between 6 and 12 years were included, 119 with epilepsy (non-idiopathic generalized 31, non-idiopathic partial 62, idiopathic 26) and 34 treated for a brain tumour. Parents answered a multidimensional questionnaire on child's autonomy and cognitive or behavioural difficulties, impact of the illness on their own everyday life, and rehabilitation. RESULTS: Learning difficulties were reported by a majority of parents in all groups. Behavioural and autonomy problems were more often reported in the non-idiopathic generalized epilepsy group. Report of tiredness was more frequent and of disrupting behaviour less frequent in the tumour group than in epilepsy. Impact of the child's illness on parents' QOL was strong in all groups, and stronger in case of severe forms of epilepsy. CONCLUSIONS: Parental concerns are important to consider for rehabilitation programmes adapted to each child with these neurological conditions.