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Using vertical spin-valve devices, we experimentally investigate the room-temperature spin diffusion length in an undoped p -Ge layer grown on ferromagnetic Fe 3 Si. Because low-temperature molecular beam epitaxy techniques enable us to grow vertically stacked and all-epitaxial CoFe/Ge/Fe 3 Si trilayers on Si(111), we can intentionally vary the thickness (t Ge ) of the intermediate undoped p -Ge layer during the growth. With decreasing t Ge , the magnitude of the spin signals gradually increases at room temperature. From the analysis based on the model by Fert and Jaffrès, the room-temperature spin diffusion length in the undoped p -Ge grown on Fe 3 Si is experimentally estimated to be ∼ 8.4 nm, much shorter than those reported in previous works on commercial p -Ge substrates. [ABSTRACT FROM AUTHOR]

Background and Objectives: To clarify whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection cause acute encephalopathy in children and which are the most common syndromes that cause them and what are the outcomes., Methods: A nationwide web-based survey among all members of the Japanese Society of Child Neurology to identify pediatric patients aged < 18 years who developed acute encephalopathy in Japan between 1 January 2020 and 31 May 2022 associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection confirmed by polymerase chain reaction or antigen tests using pharyngeal swabs. Acute encephalopathy was defined as acute onset of impaired consciousness lasting > 24 h or an altered mental state; neurological symptoms arising within 2 weeks of onset of COVID-19 or multisystem inflammatory syndrome in children (MIS-C)/pediatric inflammatory multisystem syndrome (PIMS); evidence of SARS-CoV-2 infection; and reasonable exclusion of other diseases. Patients were divided into the known clinico-radiological acute encephalopathy syndrome group and unexplained or unclassifiable acute encephalopathy group. Outcomes were assessed by pediatric cerebral performance category (PCPC) score at hospital discharge., Results: Of the 3,802 society members, 217 representing institutions responded, and 39 patients with suspected acute encephalopathy were reported, of which 31 met inclusion criteria. Of these patients, 14 were diagnosed with known clinico-radiological acute encephalopathy syndromes, with acute encephalopathy with biphasic seizures and late reduced diffusion (five patients) being the most common. Five developed acute encephalopathy associated with MIS-C/PIMS. Among 31 patients, 9 (29.0%) had severe sequelae or died (PCPC ≥ 4). Two of three patients with encephalopathy with acute fulminant cerebral edema and two with hemorrhagic shock and encephalopathy syndrome died. The PCPC scores were higher in the known clinico-radiological acute encephalopathy syndrome group than in the unexplained or unclassifiable acute encephalopathy group ( P < 0.01)., Discussion: Acute encephalopathy related to SARS-CoV-2 infection was demonstrated to be more severe than that caused by other viruses in Japan. Acute encephalopathy syndromes characterized by specific neuroradiological findings was associated with poor clinical outcomes., Competing Interests: HS received a University–Industry Joint Research Fund from Meiji Co., Ltd. KK received research funds from Syneos Health Clinical Co., Ltd. for the clinical trial of Zogenix. The funders were not involved in the study design, collection, analysis, interpretation of data, the writing of this article or the decision to submit it for publication. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Sakuma, Takanashi, Muramatsu, Kondo, Shiihara, Suzuki, Okanari, Kasai, Mitani, Nakazawa, Omata, Shimoda, Abe, Maegaki, Murayama, Murofushi, Nagase, Okumura, Sakai, Tada and Mizuguchi.)

Interstitial microdeletions in the long arm of chromosome 3 are rare. In this study, we identified two patients with approximately 5-Mb overlapping deletions in the 3q26.2q26.31 region. Both patients showed neurodevelopmental delays, congenital heart defects, and distinctive facial features. One of them showed growth deficiency and brain abnormalities, as shown on a magnetic resonance imaging scan. Haploinsufficiency of NLGN1 and FNDC3B present in the common deletion region was considered to be responsible for neurodevelopmental delay and the distinctive features, respectively. The possibility of unmasked variants in PLD1 was considered and analyzed, but no possible pathogenic variant was found, and the mechanism of the congenital heart defects observed in the patients is unknown. Because 3q26.2q26.31 deletions are rare, more information is required to establish genotype-phenotype correlations associated with microdeletions in this region., (© 2022 Wiley Periodicals LLC.)

Interstitial microdeletions in the proximal region of the long arm of chromosome 6 are rare. Herein we have reported 12 patients with developmental delays associated with interstitial microdeletions in 6q ranging from q12 to q22. The microdeletions were detected by chromosomal microarray testing. To confirm the clinical significance of these deletions, genotype-phenotype correlation analysis was performed using genetic and predicted loss-of-function data. SIM1 was recognized as the gene responsible for developmental delay, particularly in Prader-Willi syndrome-like phenotypes. Other genes possibly related to developmental delay were ZNF292 , PHIP , KCNQ5 , and NUS1 . To further establish the correlation between the genotype and phenotype, more patient information is required., Competing Interests: The authors have no conflicts of interest to disclose., (2022, International Research and Cooperation Association for Bio & Socio - Sciences Advancement.)

Objective: We examined the clinical manifestations of acute encephalopathy (AE) and identify risk factors for AE in children with tuberous sclerosis complex (TSC)., Methods: The clinical data of 11 children with clinically diagnosed TSC associated with AE and 109 children with clinically diagnosed TSC alone aged 4 years or older were collected from 13 hospitals., Results: Of the 11 children with AE, 5 had histories of febrile seizures (FS), and all had histories of febrile status epilepticus (FSE). AE developed within 24 h after fever onset in all children with seizures lasting 30 min or longer. All children developed coma after seizure cessation. Head magnetic resonance imaging (MRI) revealed widespread abnormalities in the cerebral cortex, subcortical white matter, corpus callosum, basal ganglia, and thalamus. One child died; seven had severe neurological sequelae; and the other three, mild sequelae. Logistic regression analysis revealed that a history of FSE was correlated with the development of AE., Significance: AE in children with TSC was characterized by sudden onset after fever, followed by coma, widespread brain edema evident on MRI, and poor outcomes. A history of FSE was a risk factor for the development of AE.

Background: Tuberous sclerosis complex (TSC)-associated neuropsychiatric disorders (TAND) have a large impact on patients and their families. Improving intellectual ability outcomes using preventive vigabatrin (VGB) treatment has recently been reported., Aim: The aim of this study was to investigate the severity of behavioral problems and degree of distress among families of patients with TSC with and without a history of VGB treatment., Method: The study enrolled 21 children and adolescents who were patients with TSC from four hospitals: 14 in the VGB group and 7 in the no-VGB group. To evaluate patients' psychiatric and neurological symptoms, we used the TAND Checklist, Aberrant Behavior Checklist (ABC), Social Communication Questionnaire (SCQ), and Social Responsive Scale-2nd edition (SRS-2)., Results: All VGB-group patients were administered VGB after the onset of epileptic seizures. No obvious differences were observed between the VGB and no-VGB groups in behavioral problem scores on the TAND Checklist, or on the ABC, SCQ, and SRS-2 total scores. Behavioral problem scores were lower in patients with normal intelligence than in those with mild intellectual disability (ID; P = 0.042). Degrees of family distress assessed with the TAND Checklist were not correlated with the intelligence quotient/developmental quotient (IQ/DQ) or seizure frequency but were correlated with the total SRS-2 scores (P = 0.022). For several patients, there were large discrepancies between familial and physician ratings of the TAND impact score., Conclusion: Children and adolescents with TSC may present with significant behavioral difficulties and family distress, regardless of whether they were treated with VGB or not after the onset of seizures. Difficulties in social communication may have the strongest "TAND impact" on families., Competing Interests: Declaration of competing interest Mitsugu Uematsu declares the following competing interests: This study was funded by The NOVARTIS Foundation (Japan) for the Promotion of Science (Novartis Research Grants 2016 and 2017). The other authors (Yurika Numata-Uematsu, Yu Aihara, Tomoko Kobayashi, Mayu Fujikawa, Noriko Togashi, Takashi Shiihara, Kei Ohashi, Ayako Hattori, Shinji Saitoh, Shigeo Kure) declare no competing interests., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Pyridoxine-dependent epilepsy (PDE) is a rare autosomal-recessive disorder typically presenting with neonatal seizures and is sometimes difficult to diagnose, because the clinical features mimic those of birth asphyxia. A Japanese newborn boy presented with pulmonary haemorrhage and convulsions on the day of birth. Brain computed tomography showed diffuse, but mild, low-density cerebral white matter and a thin subdural hematoma in the posterior fossa. He did not have thrombocytopenia or coagulopathy. His respiratory status improved with conservative treatment, but his convulsions were persistent even after prescription of several antiepileptic drugs. His serum and cerebrospinal fluid showed decreased vitamin B6 vitamers and increased upstream metabolites of α-aminoadipic semialdehyde dehydrogenase, strongly suggesting a diagnosis of PDE; the epileptic spasms ceased after administration of intravenous pyridoxal phosphate hydrate. Gene analysis revealed novel compound heterozygous mutations in ALDH7A1 that included NM&#95;001182.4:[c.1196G > T] and [c.1200 + 1G > A]. Atypical birth asphyxia with persistent neonatal seizure should prompt vitamin B6/metabolite screening., (© The Author(s) 2020. Published by Oxford University Press.)

Objectives: Acute encephalopathy is an acute brain dysfunction after preceding infection, consisting of multiple syndromes. Some syndromes, such as acute encephalopathy with biphasic seizures and late reduced diffusion (AESD), are severe with poor outcome, whereas others, such as clinically mild encephalitis/encephalopathy with reversible splenial lesion (MERS), are mild with favorable outcome. Previous study reported the association of the thermolabile polymorphism in Carnitine Palmitoyltransferase 2 (CPT2) gene and severe syndromes of acute encephalopathy. To further explore the pathogenetic role of CPT2 in acute encephalopathy, we conducted a case-control association study of a typical thermolabile CPT2 polymorphism, rs2229291, in 416 patients of acute encephalopathy, including both severe and mild syndromes., Methods: The case cohort consisted of 416 patients, including AESD, MERS, and other syndromes. The control subjects were 100 healthy Japanese. rs2229291 was genotyped by Sanger sequencing. Genetic distribution was compared between the patients and controls using Cochran-Armitage trend test., Results: Minor allele frequency of rs2229291 was significantly higher in AESD (p = 0.044), MERS (p = 0.015) and entire acute encephalopathy (p = 0.044) compared to the controls. The polymorphism showed no significant association with influenza virus, or with outcome., Conclusions: This study provided evidence that CPT2 is a susceptibility gene for overall acute encephalopathy, including both severe and mild syndromes, and suggested that impairment of mitochondrial metabolism is common to various syndromes of acute encephalopathy., (Copyright © 2019 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

Although there are many known Mendelian genes linked to epileptic or developmental and epileptic encephalopathy (EE/DEE), its genetic architecture is not fully explained. Here, we address this incompleteness by analyzing exomes of 743 EE/DEE cases and 2366 controls. We observe that damaging ultra-rare variants (dURVs) unique to an individual are significantly overrepresented in EE/DEE, both in known EE/DEE genes and the other non-EE/DEE genes. Importantly, enrichment of dURVs in non-EE/DEE genes is significant, even in the subset of cases with diagnostic dURVs (P = 0.000215), suggesting oligogenic contribution of non-EE/DEE gene dURVs. Gene-based analysis identifies exome-wide significant (P = 2.04 × 10 -6 ) enrichment of damaging de novo mutations in NF1, a gene primarily linked to neurofibromatosis, in infantile spasm. Together with accumulating evidence for roles of oligogenic or modifier variants in severe neurodevelopmental disorders, our results highlight genetic complexity in EE/DEE, and indicate that EE/DEE is not an aggregate of simple Mendelian disorders.

Background: Rhinovirus is a common respiratory pathogen for children throughout the year; nevertheless, its central nervous system involvement is extremely rare, and only two cases have been reported to date: meningitis and sepsis-like illness., Patient: A previously healthy 2-year-old Japanese boy developed fever, followed by seizures and lethargy. His cerebrospinal fluid cell count and protein level were slightly increased; brain magnetic resonance imaging showed abnormal intensities in the bilateral cerebellar dentate nuclei, which were prominent in diffusion-weighted images. After his consciousness disturbance improved, cerebellar dysfunction became apparent. He was treated symptomatically, without steroids or any other immunosuppressants. He almost recovered within a few months; however, cerebellar atrophy became evident on brain magnetic resonance imaging. Using acute specimens, human rhinovirus A was detected in his throat swab and cerebrospinal fluid., Discussion: Acute cerebellitis, in which cerebellar inflammation is predominant, is occasionally accompanied by cerebral symptoms, such as consciousness disturbance and seizures. As a causative pathogen, rotavirus is the most common; however, rhinovirus-associated acute encephalitis/encephalopathy and concurrent cerebellitis have not been reported before. Further research, using recent molecular techniques to detect various central nervous system pathogens, including rhinovirus, is needed to delineate the underlying pathophysiology., (Copyright © 2019 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

Introduction: Sweet potato may contain furanoterpenoids, including ipomeamarone, which cause lung edema., Case Presentation: A 10-year-old schoolgirl was hospitalized with asthma exacerbation and acute pneumonia. Chest radiographs showed a diffuse opacity of the left lung and hyperpermeability of the right lung. Computed tomography indicated foreign-body aspiration. Flexible bronchoscopy revealed an inhaled piece of sweet potato obstructing the left main bronchus. Although the patient's dyspnea worsened after removal of the sweet potato, she recovered with the treatment based on the 2014 Japanese Childhood Asthma Guidelines., Conclusion: Cases of sweet potato aspiration need careful treatment after removal of the foreign body.

Objective: α ( CAMK2A ) and β ( CAMK2B ) isoforms of Calcium/calmodulin-dependent protein kinase II (CaMKII) play a pivotal role in neuronal plasticity and in learning and memory processes in the brain. Here, we explore the possible involvement of α - and β -CaMKII variants in neurodevelopmental disorders., Methods: Whole-exome sequencing was performed for 976 individuals with intellectual disability, developmental delay, and epilepsy. The effect of CAMK2A and CAMK2B variants on CaMKII structure and firing of neurons was evaluated by computational structural analysis, immunoblotting, and electrophysiological analysis., Results: We identified a total of five de novo CAMK2A and CAMK2B variants in three and two individuals, respectively. Seizures were common to three individuals with CAMK2A variants. Using a minigene splicing assay, we demonstrated that a splice site variant caused skipping of exon 11 leading to an in-frame deletion of the regulatory segment of CaMKII α . By structural analysis, four missense variants are predicted to impair the interaction between the kinase domain and the regulatory segment responsible for the autoinhibition of its kinase activity. The Thr286/Thr287 phosphorylation as a result of release from autoinhibition was increased in three mutants when the mutants were stably expressed in Neuro-2a neuroblastoma cells. Expression of a CaMKII α mutant in primary hippocampal neurons significantly increased A-type K + currents, which facilitated spike repolarization of single action potentials., Interpretation: Our data highlight the importance of CaMKII α and CaMKII β and their autoinhibitory regulation in human brain function, and suggest the enhancement of A-type K + currents as a possible pathophysiological basis.

Background: Mumps is a common childhood viral disease characterized by fever and swelling of the parotid gland. The prognosis is generally good, although some complications, such as encephalitis (0.1%), exist. Acute encephalopathy with biphasic seizures and late reduced diffusion is the most common type of acute encephalopathy. However, this type of encephalopathy has not been reported in association with mumps infection., Patient: A previously healthy 3-year-old Japanese boy had a brief convulsion after fever for 3days, and then had conscious disturbance and parotitis. After several days, he had a second brief convulsion and was admitted. Increased serum amylase levels and presence of anti-mumps immunoglobulin M antibody confirmed mumps parotitis. The patient had another brief seizure later the day of admission. He did not have status or cluster seizures, although the biphasic nature of his seizures, conscious disturbance between the seizures, no pleocytosis in cerebrospinal fluid, and brain magnetic resonance images were consistent with acute encephalopathy with biphasic seizures and late reduced diffusion., Discussion: In Japan, the mumps vaccine is not administered as a part of routine immunizations. It thus has low coverage (30-40%), and as a result, mumps infections are still common. However, this is the first case of mumps-related acute encephalopathy with biphasic seizures and late reduced diffusion. This case may be representative of only a minority of patients with mumps-associated central nervous system involvement. Nevertheless, this diagnostic possibility may be considered. In order to prevent mumps-related complications, routine mumps vaccination might be warranted., (Copyright © 2017 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

Galloway-Mowat syndrome (GAMOS) is an autosomal-recessive disease characterized by the combination of early-onset nephrotic syndrome (SRNS) and microcephaly with brain anomalies. Here we identified recessive mutations in OSGEP, TP53RK, TPRKB, and LAGE3, genes encoding the four subunits of the KEOPS complex, in 37 individuals from 32 families with GAMOS. CRISPR-Cas9 knockout in zebrafish and mice recapitulated the human phenotype of primary microcephaly and resulted in early lethality. Knockdown of OSGEP, TP53RK, or TPRKB inhibited cell proliferation, which human mutations did not rescue. Furthermore, knockdown of these genes impaired protein translation, caused endoplasmic reticulum stress, activated DNA-damage-response signaling, and ultimately induced apoptosis. Knockdown of OSGEP or TP53RK induced defects in the actin cytoskeleton and decreased the migration rate of human podocytes, an established intermediate phenotype of SRNS. We thus identified four new monogenic causes of GAMOS, describe a link between KEOPS function and human disease, and delineate potential pathogenic mechanisms.

Background: Congenital cytomegalovirus (CMV) infection causes various neurological sequelae. However, most infected infants are asymptomatic at birth, and retrospective diagnosis is difficult beyond the neonatal period., Objective: This study aimed to investigate the aspects of neurological sequelae associated with asymptomatic congenital CMV infection., Methods: We retrospectively analyzed 182 patients who were suspected of having asymptomatic congenital CMV infection with neurological symptoms in Japan. Congenital CMV infection was diagnosed by quantitative polymerase chain reaction amplification of CMV from dried umbilical cord DNA., Results: Fifty-nine patients (32.4%) who tested positive for CMV were confirmed as having congenital CMV infection. Among 54 congenital CMV patients, major neurological symptoms included intellectual disability (n=51, 94.4%), hearing impairment (n=36, 66.7%) and cerebral palsy (n=21, 38.9%), while microcephaly (n=16, 29.6%) and epilepsy (n=14, 25.9%) were less common. In a brain magnetic resonance imaging (MRI) study, cortical dysplasia was observed in 27 CMV-positive patients (50.0%), and all patients (100%) had cerebral white matter (WM) abnormality. Intracranial calcification was detected by CT in 16 (48.5%) of 33 CMV-positive patients. Cerebral palsy, cortical dysplasia and a WM abnormality with a diffuse pattern were associated with marked intellectual disability., Conclusions: Brain MRI investigations are important for making a diagnosis and formulating an intellectual prognosis. Analysis of umbilical cord tissue represents a unique and useful way to retrospectively diagnose congenital CMV infection., (Copyright © 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

Background: Mucolipidosis IV (MLIV; OMIM #252650) is an autosomal recessive lysosomal storage disorder, frequently observed in the Ashkenazi Jewish population. MLIV typically results in intellectual disability, corneal opacities, and delayed motor milestones during infancy, with a relatively static course. To date, reports of MLIV in other ethnic groups have been sparse., Patient: The present study is a case report of a 9-year-old Japanese boy, diagnosed via whole-exome sequencing, with compound heterozygous mutations of MCOLN1 (OMIM(*)605248): c.410T>C (p.Leu137Pro) and c.802&#95;803delAG (p.Ser268Trpfs*17). Although his clinical course was mild (due to a lack of corneal clouding), other relevant features were present. These included strabismus, white matter signal abnormalities, and a hypoplastic corpus callosum at 2years of age. After a molecular diagnosis, a markedly elevated serum gastrin level (which is also common in MLIV) was confirmed., Discussion: The present results suggest that MLIV could be added as a differential diagnosis for white matter disorders, regardless of ethnicity. Beyond neurological or ophthalmologic findings, serum gastrin could be a useful diagnostic marker for MLIV., (Copyright © 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

An 11-year-old boy presented with progressive walking disturbances. He exhibited severe equinovarus feet that together presented with hyperreflexia of the patellar tendon and extensor plantar, resembling spastic paraplegia or upper neuron disease. He showed mild distal muscle atrophy, as well. We did not observe signs of cognitive impairment, cerebellar signs, or brain magnetic resonance imaging abnormalities. Nerve biopsy showed giant axon swellings filled with neurofilaments. Gene analysis revealed novel compound heterozygous missense mutations in the gigaxonin gene, c.808G>A (p.G270S) and c.1727C>A (p.A576E). He was diagnosed with mild giant axonal neuropathy (GAN) without apparent central nervous system involvement. Patients with classical GAN manifest their symptoms during early childhood. Mild GAN, particularly in early stages, can be misdiagnosed because of lack of typical hair features and incomplete or indistinct peripheral and central nervous system symptoms. This case is important since it can aid to identify atypical and milder clinical courses of GAN. This report widens the mild GAN clinical spectrum, alerting physicians for correct diagnosis., (Copyright © 2015 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) at onset manifests an early seizure (ES) usually lasting more than 30 min. Following ES, some patients exhibit almost clear consciousness with no neurological symptoms, and no MRI abnormality for a few days, which may lead to an initial misdiagnosis of prolonged febrile seizures (PFS). To allow an early diagnosis of AESD, we retrospectively analyzed clinical manifestations, laboratory data, and radiologic and EEG findings in patients with AESD (n=62) having ES of over 30 min, and ones with PFS (n=54), using logistic regression analyses. Multivariate logistic regression analysis revealed that an age below 1.5 years and a Glasgow Coma Scale score of 14 or less than 14 (Japan Coma Scale score of 1 or higher) were high risk factors of developing AESD. We proposed an AESD prediction score system consisting of consciousness level, age, duration of convulsions, enforcement of mechanical intubation, and aspartate aminotransferase, blood glucose and creatinine levels (full score: 9), the mean scores in AESD and PFS being 5.9 and 1.8, which were significantly different (p<0.001). We herein propose a scoring system for differentiating patients with AESD and PFS around the time of ES (score of 4 or more than 4 suggesting AESD), which may contribute to early therapeutic intervention and an improved neurologic outcome., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Objective: The present study aimed to evaluate the efficacy of surgical treatment for intractable aspiration in patients with severe motor and intellectual disabilities (SMID) and neuromuscular diseases (NMD)., Methods: A retrospective analysis was performed of 20 patients who underwent laryngotracheal separation (LTS) or the tracheal flap method (TFM) between 2003 and 2012 at Gunma Children's Medical Center., Results: All patients were bedridden and fed either through a naso-gastric or naso-esophageal tube or via a gastric fistula. Of the 20 participants, 60% underwent surgical treatment before 3 years of age. The incidence of aspiration pneumonia decreased after surgery, and 8 of 10 patients, who were previously hospitalized for a long duration, were discharged. The most frequent complications observed were granulation around the tracheostomy stoma and endotracheal granuloma. Two patients presented with a tracheal fistula., Conclusion: LTS and TFM can be used as treatment modalities for patients with intractable aspiration along with SMID and NMD. In patients with intractable aspiration, after considering their underlying conditions, adaptation and type of operative procedures should be determined.

KCNT1 mutations have been found in epilepsy of infancy with migrating focal seizures (EIMFS; also known as migrating partial seizures in infancy), autosomal dominant nocturnal frontal lobe epilepsy, and other types of early onset epileptic encephalopathies (EOEEs). We performed KCNT1-targeted next-generation sequencing (207 samples) and/or whole-exome sequencing (229 samples) in a total of 362 patients with Ohtahara syndrome, West syndrome, EIMFS, or unclassified EOEEs. We identified nine heterozygous KCNT1 mutations in 11 patients: nine of 18 EIMFS cases (50%) in whom migrating foci were observed, one of 180 West syndrome cases (0.56%), and one of 66 unclassified EOEE cases (1.52%). KCNT1 mutations occurred de novo in 10 patients, and one was transmitted from the patient's mother who carried a somatic mosaic mutation. The mutations accumulated in transmembrane segment 5 (2/9, 22.2%) and regulators of K(+) conductance domains (7/9, 77.8%). Five of nine mutations were recurrent. Onset ages ranged from the neonatal period (<1 month) in five patients (5/11, 45.5%) to 1-4 months in six patients (6/11, 54.5%). A generalized attenuation of background activity on electroencephalography was seen in six patients (6/11, 54.5%). Our study demonstrates that the phenotypic spectrum of de novo KCNT1 mutations is largely restricted to EIMFS., (Wiley Periodicals, Inc. © 2015 International League Against Epilepsy.)

We describe two unrelated patients with terminal deletions in the long arm of chromosome 13 showing brain malformation consisting of holoprosencephaly and cerebellar vermis hypoplasia. Array comparative genomic hybridization analysis revealed a pure terminal deletion of 13q31.3q34 in one patient and a mosaic ring chromosome with 13q32.2q34 deletion in the other. Mutations in ZIC2, located within region 13q32, cause holoprosencephaly, whereas the 13q32.2q32.3 region is associated with cerebellar vermis hypoplasia (Dandy-Walker syndrome). The rare concurrence of these major brain malformations in our patients provides further evidence that 13q32.2q32.3 deletion, harboring ZIC2 and ZIC5, leads to cerebellar dysgenesis., (Copyright © 2014 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

Introduction: The ketogenic diet is a valuable therapy for patients with intractable epilepsy, but it can result in a variety of complications that sometimes limits its usefulness. Hypoproteinemia is one of the common adverse effects of this diet, although the underling mechanism is largely unknown except for the diet's reduced protein intake. Only one case of protein-losing enteropathy during the ketogenic diet has been reported., Patient Description: A previously healthy 9-year-old girl experienced fever for 5 days then suddenly developed convulsive seizures that subsequently evolved to severe refractory status epilepticus. After multiple antiepileptic drugs failed to improve the patient's condition, we introduced the ketogenic diet. Although her seizures diminished, her course was complicated by hypoproteinemia. An abdominal dynamic scintigraphy and colonoscopy findings indicated protein-losing enteropathy with nonspecific mucosal inflammation. Her nutritional status deteriorated; thus, we discontinued the ketogenic diet. Her nutritional status gradually improved, whereas her seizures increased., Discussion: Hypoproteinemia during the ketogenic diet is common, but the underlying etiologies are not well understood. Abdominal dynamic scintigraphy could be valuable for clarifying the etiology of hypoproteinemia during the ketogenic diet., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: Pelizaeus-Merzbacher disease (PMD), a hypomyelinating leukodystrophy, and the related but less severe allelic spastic paraplegia 2 (SPG2) are caused by mutations in the proteolipid protein 1 (PLP1) gene. Magnetic resonance imaging (MRI) is pivotal for diagnosing these disorders. The severity of PMD/SPG2 varies, and for a milder form of PMD, there have been some reports of near-normal findings in T1-weighted images but abnormal findings in T2-weighted images., Patient: We report the case of a 5-year-old boy diagnosed with a milder form of PMD caused by a novel PLP1 mutation in exon 3: c.300delC (p.I100IfsX13). He had delayed development from several months of age and was able to walk with support at 19 months in spite of the spasticity in his lower extremities. Hypomyelination was noted at 12 months by brain MRI. Motor nerve conduction studies showed decreased velocities with reduced amplitudes. Follow-up MRI at 1-year intervals from 18 months until 55 months of age showed gradual myelination progress., Discussion: The single nucleotide deletion identified in this patient can cause a frameshift and premature termination of PLP1. Via the nonsense-mediated mRNA decay mechanism of this mutation will result in loss-of-function, leading to a milder form of PMD. The present case is compatible with previously reported cases of milder form of PMD. We incidentally identified progressive myelination in this patient by T1-weighted images obtained by serial MRI. This finding adds to our understanding of the pathological stages of a milder form of PMD., (Copyright © 2014 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

We retrospectively collected three patients with clinically mild encephalitis with a reversible splenial lesion (MERS) after mumps vaccination, and reviewed five patients, including two patients previously reported. The five patients (all males, aged 1 to 9) presented with fever, vomiting, or headache as the initial symptoms (day 0), suggesting meningitis, at 13 to 21 days after mumps vaccination. Consciousness disturbance, delirious behavior, seizures, or dysarthria was observed on days 1 to 3, which had completely resolved before day 11. Hyponatremia was observed in all patients. A cerebrospinal fluid study showed pleocytosis, and confirmed the vaccine strain genome. MRI revealed reduced diffusion in the splenium of the corpus callosum on days 2 to 4, which had completely disappeared on the follow-up studies performed on days 7-15. EEG showed high voltage slow wave in three patients, which later normalized. These findings led to a diagnosis of MERS after mumps vaccination. MERS after mumps vaccination may be more common than previously considered. MERS is suspected when a male patient after mumps vaccination presents with neurological symptoms with hyponatremia, following symptoms of aseptic meningitis, and MRI would be performed to examine the splenium of the corpus callosum., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Background: There have been numerous reports regarding serum or cerebrospinal fluid (CSF) biomarkers in various disorders; however, the validities of such biomarkers for more precise diagnoses and prognosis estimates remain to be determined, especially in pediatric patients with neurological disorders., Methods: Serum/CSF S100B, neuron-specific enolase, and total tau (tTau) were measured in various acute pediatric neurological disorders, and their usefulness for diagnostic and prognostic predictions was validated using receiver operating characteristic curves and area under the curve (AUC) analysis., Results: A total of 336 serum and 200 CSF specimens from 313 patients were examined, and we identified statistically significant differences that were relevant from diagnostic and prognostic viewpoints. CSF and serum tTau levels could be good predictors for diagnosis (CSF tTau; AUC=0.76) and prognosis (serum tTau; AUC=0.78)., Conclusions: Both CSF and serum tTau levels could be useful for precise diagnostic and prognostic estimations in acute pediatric neurological disorders. Further studies are needed to clarify the clinical significance of such biomarkers., (Copyright © 2013 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

Heterotrimeric G proteins, composed of α, β, and γ subunits, can transduce a variety of signals from seven-transmembrane-type receptors to intracellular effectors. By whole-exome sequencing and subsequent mutation screening, we identified de novo heterozygous mutations in GNAO1, which encodes a Gαo subunit of heterotrimeric G proteins, in four individuals with epileptic encephalopathy. Two of the affected individuals also showed involuntary movements. Somatic mosaicism (approximately 35% to 50% of cells, distributed across multiple cell types, harbored the mutation) was shown in one individual. By mapping the mutation onto three-dimensional models of the Gα subunit in three different complexed states, we found that the three mutants (c.521A>G [p.Asp174Gly], c.836T>A [p.Ile279Asn], and c.572&#95;592del [p.Thr191&#95;Phe197del]) are predicted to destabilize the Gα subunit fold. A fourth mutant (c.607G>A), in which the Gly203 residue located within the highly conserved switch II region is substituted to Arg, is predicted to impair GTP binding and/or activation of downstream effectors, although the p.Gly203Arg substitution might not interfere with Gα binding to G-protein-coupled receptors. Transient-expression experiments suggested that localization to the plasma membrane was variably impaired in the three putatively destabilized mutants. Electrophysiological analysis showed that Gαo-mediated inhibition of calcium currents by norepinephrine tended to be lower in three of the four Gαo mutants. These data suggest that aberrant Gαo signaling can cause multiple neurodevelopmental phenotypes, including epileptic encephalopathy and involuntary movements., (Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)

A 23-month-old Japanese girl with a severe form of congenital fiber type disproportion myopathy under mechanical ventilation suffered from respiratory syncytial virus (RSV) bronchiolitis, complicated with acute encephalopathy. She showed consciousness disturbance and convulsions followed by severe brain damage, a rare complication in RSV infection. Patients with severe neuromuscular diseases are vulnerable to RSV infection. Prophylactic interventions should be recommended., (© 2012 The Authors. Pediatrics International © 2012 Japan Pediatric Society.)

We describe a boy with Fisher syndrome. He presented the typical symptoms of Fisher syndrome, including external ophthalmoplegia, abnormality of convergence, and areflexia, after an episode of Campylobacter enterocolitis. Atypically, however, anti-GA1 antibody was detected in his serum, though anti-GQ1b and anti-GT1a antibodies were not. In addition, the tau protein level in his cerebrospinal fluid was elevated. Generally, Fisher syndrome is a self-limiting disease and has a good prognosis. In our patient, however, mild diplopia and areflexia persisted 6 months after their onset. Here, we report on the first Fisher syndrome patient with anti-GA1 antibody in the serum and elevated tau protein in the cerebrospinal fluid., (Copyright © 2011 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

Background: Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is characterized clinically by biphasic seizures and late magnetic resonance imaging abnormalities, such as reduced subcortical diffusion from day 3 onwards, often accompanied with some neurological sequelae. In the early stages of the disease, AESD closely resembles its far more prevalent and relatively benign counterpart, febrile seizure (FS)., Methods: We measured and compared the serum or cerebrospinal fluid (CSF) levels of S100B, neuron-specific enolase (NSE), and total tau protein in 43 patients with FS and 18 patients with AESD, at any point during the disease. To assess early diagnostic validity, we compared these biomarkers in 43 FS and eight AESD patients, with whom the day 0-2 samples were available. We used the receiver-operator characteristic curve to evaluate the diagnostic values of these markers., Results: The levels of all biomarkers were significantly higher in AESD than FS patients. When only day 0-2 samples from AESD patients were used, the levels of all the measured biomarkers, except serum NSE, were still significantly higher in patients with AESD than in FS, suggesting that AESD could damage astrocytes, neurons, and axons, even in the early stages of the disease. According to the receiver-operator characteristic curve analyses, CSF S100B (cut-off value, 100 pg/mL) and CSF total tau protein (cut-off value, 100 pg/mL) were better predictors of AESD than other biomarkers., Conclusion: The combination of CSF S100B and CSF total tau protein resulted in a positive predictive value of AESD 83.3%, which could be helpful for early diagnosis, facilitating early therapeutic interventions., (© 2011 The Authors. Pediatrics International © 2011 Japan Pediatric Society.)

Alexander disease is a major entity of leukodystrophy; magnetic resonance imaging (MRI) studies of the brain typically show extensive changes in the cerebral white matter with frontal predominance. Heterozygous missense mutations of GFAP are thought to be sufficient for the molecular diagnosis, which has widened the Alexander disease entity beyond the classical one. We report the patient, a 16-year-old Japanese boy, with infantile-onset Alexander disease, showing striking MRI findings; extreme white matter loss of cerebrum through cerebellum, severe atrophy of basal ganglia, cerebellum, brain stem, and cervical spinal cord. Molecular analysis showed a heterozygous mutation R239L (c.730G>T) in GFAP. A relative long disease course, over 15years, with the help of mechanical ventilation revealed the striking MRI progression., (Copyright © 2010 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)