The Utility of Limited-Montage Electroencephalography for Seizure Detection in Children.

BACKGROUND: The primary objective of this study was to investigate the utility of limited-montage electroencephalography (EEG) for seizure detection in children. We also aimed to determine whether the detection rate differed among different montage patterns. METHODS: This study was carried out between November 2019 and October 2020 at a tertiary children's hospital in Japan. The subjects were inpatients in the pediatric intensive care unit who had an epileptic seizure during EEG monitoring. Each patient's EEG record, consisting of a 15-minute recording during an epileptic seizure and a 15-minute recording in the absence of an epileptic seizure, was extracted from the medical charts. The EEG data were then analyzed using six, limited-montage coverage patterns: (1) Fp1-C3, Fp2-C4, (2) Fp1-O1, Fp2-O2, (3) Fp1-T3, Fp2-T4, (4) C3-O1, C4-O2, (5) C3-T3, C4-T4, and (6) O1-T3, O2-T4. The sensitivity and specificity of each montage for seizure detection was analyzed. RESULTS: One hundred thirty-two EEG data points from 11 patients were examined. Sensitivity and specificity were the highest for Fp1-O1 and Fp2-O2 at 73% and 91%, respectively. Overall, the montage covering the frontopolar area had the highest detection rate, followed by the montage covering the occipital, central, and temporal areas. CONCLUSION: Limited-montage EEG identified seizures in children hospitalized in the intensive care unit, but the detection rate differed by montage coverage. The detection rate was highest in the montage covering the frontopolar area.

HPeV3-associated acute encephalitis/encephalopathy among Japanese infants.

OBJECTIVE: The current study aimed to identify and compare the clinical characteristics of human parechovirus type 3 (HPeV3)-associated acute encephalitis/encephalopathy (HPeV3E/E) between infants with abnormal brain magnetic resonance imaging (MRI) findings (typical, or MRI-positive HPeV3E/E) and those with MRI-negative findings (MRI-negative HPeV3E/E). METHODS: This is a retrospective study on patients with HPeV3 infection, and a two-step questionnaire survey performed on 837 hospitals in Japan between 2014 and 2016. RESULTS: We identified 240 infants with HPeV3 infection, of which 34 had been clinically-diagnosed HPeV3E/E (cHPeV3E/E). However, detailed clinical data were provided by 32 of the 34 patients. Among these 32, 23 had undergone MRI and were categorized into two groups, MRI-positive (n = 17) and -negative (n = 6). There were no significant intergroup differences in clinical lab results or symptoms, except for gastrointestinal symptoms that were only present in the MRI-negative patients. The MRI-positive group showed white matter involvement on brain MRI during the acute phase, and 8 patients presented with lesions on follow-up MRI. Furthermore, 4 (50%) of the 8 patients had neurological sequelae. CONCLUSION: Clinical characteristics of cHPeV3E/E patients with and without lesions on brain MRI showed no significant differences. Therefore, considering the difficulty in distinguishing febrile infants with cHPeV3E/E from those with a sepsis-like illness, during an HPeV3 infection epidemic, it is imperative to frequently perform brain MRI in febrile infants presenting with severe disease for the early diagnosis of HPeV3E/E presenting with brain lesions.

Refractory cerebral infarction in a child with an ACTA2 mutation.

INTRODUCTIONS: A specific mutation in the ACTA2 gene is known to cause multisystemic smooth muscle dysfunction syndrome, which is associated with cerebrovascular diseases and various organ disorders. Cerebral infarctions resulting from severe vasculopathy can be refractory; however, there are no previous reports describing the detailed clinical course of recurrent cerebral infarctions due to an ACTA2 mutation. Herein, we report a patient with an ACTA2 mutation who experienced multiple refractory cerebral infarctions in early childhood. PATIENT DESCRIPTION: The patient was aged 1 year and 5 months at her first episode of cerebral infarction. Arteriopathy due to an ACTA2 mutation was diagnosed based on the characteristic cerebrovascular findings and abnormal physical findings, such as bilateral dilated pupils. Bilateral encephaloduroarteriosynangiosis and encephalogaleosynangiosis were performed after the first episode. Because the cerebral infarctions recurred postoperatively, administration of cilostazol followed by bosentan was started. However, despite these treatments she experienced seven cerebral infarctions by age 2 years and 6 months. INTERPRETATION: Cerebral infarctions in patients with a specific ACTA2 mutation can occur even in early childhood, recur frequently, and cause severe motor and cognitive impairment. Physicians should be highly aware of this disease and be ready to provide the medical and surgical interventions necessary to minimize the disabling sequelae.

Coloboma may be a shared feature in a spectrum of disorders caused by mutations in the WDR37-PACS1-PACS2 axis.

We report a male adult with early infantile-onset epilepsy, facial dysmorphism, and iridal and choroidal coloboma who had a de novo heterozygous mutation in PACS2, that is, c.625G > A p.(Glu209Lys). This specific mutation was previously reported in a patient with PACS2-related disorder (early infantile epileptic encephalopathy 66). De novo heterozygous mutations in WDR37 have been shown to cause a novel human disorder, neurooculocardiogenitourinary syndrome (NOCGUS syndrome) (OMIM #618652), characterized by intellectual disability, facial dysmorphism, and coloboma. According to large-scale interactome data, WDR37 interacts most strongly, by far, with PACS1 and PACS2. Clinically, coloboma has been described as a feature in a WDR37-related disorder and a PACS1-related disorder (Schuurs-Hoeijmakers syndrome), but not in a PACS2-related disorder. Our review of the phenotypes of three human disorders caused by WDR37, PACS1, and PACS2 mutations showed a significant overlap of epilepsy, intellectual disability, cerebellar atrophy, and facial features. The present observation of coloboma as a shared feature among these three disorders suggests that this group of genes may be involved in ocular development. We propose that dysregulation of the WDR37-PACS1-PACS2 axis results in a spectrum that is recognizable by intellectual disability, distinctive facial features, and coloboma.

Hereditary spastic paraplegia masqueraded by congenital melanocytic nevus syndrome: Dual pathogenesis of germline non-mosaicism and somatic mosaicism.

Neurocutaneous disorders are caused by germline and/or somatic mutations and involve the integument and central nervous systems. Congenital melanocytic nevus syndrome is characterized by melanotic skin lesions caused by somatic mutations at codon 61 in NRAS. A large cutaneous lesion raises the risk of central nervous system involvement. We report an 8-year-old girl with a congenital giant pigmented nevus that covered almost her entire back. Despite the absence of any radiological evidence of intracranial melanosis, the patient exhibited progressive limb spasticity with preserved intellectual ability. An extensive genetic analysis identified a specific class of heterozygous germline mutation in SPAST, p.(Arg499His), which is responsible for hereditary spastic paraplegia with infantile onset. In addition, a known heterozygous somatic mutation in NRAS, p.(Gln61Lys) was detected in the cutaneous lesion. This observation recapitulates concomitant mosaicism and non-mosaicism within a single individual and suggests that the possibility of a dual genetic diagnosis should be considered when neurological decline is observed in a patient with a neurocutaneous disorder without any detectable intracranial lesions.

CNOT2 as the critical gene for phenotypes of 12q15 microdeletion syndrome.

Chromosome 12q15 microdeletion syndrome is characterized by intellectual disability and dysmorphic facial features, but the associations between each of the deleted genes and the phenotypes of 12q15 microdeletion syndrome remain unclear. Recently, the smallest region of overlap in 16 previously reported patients was used to define three candidate genes for the 12q15 microdeletion syndrome: CNOT2, KCNMB4, and PTPRB. Among these three candidate genes, CNOT2 maintains the structural integrity of the carbon catabolite repressor 4 (CCR4)-negative on TATA (NOT) complex, which plays a key role in regulating global gene expression, and is essential for the enzymatic activity of the CCR4-NOT complex. Disruption of the CCR4-NOT complex results in dysregulation of global gene expression, and is associated with various human disease processes, including neuronal diseases. Therefore, CNOT2 haploinsufficiency might account for the neurological features of the 12q15 microdeletion syndrome. Herein, we document a 12-year-old female patient with mild intellectual disability and multiple structural abnormalities including cleft lip and palate and 2-3 toe syndactyly. She exhibited dysmorphic facial features such as upslanting and short palpebral fissures, micrognathia, low-set ears, and hypoplastic antihelix. A microarray analysis showed a de novo 1.32-Mb deletion within 12q15 that included CNOT2 and 14 other genes. Remapping of the 12q15 deletion region in the 16 previously reported patients together with that in the newly identified patient indicated that CNOT2 is the only gene that is commonly deleted. These findings suggest that CNOT2 is the prime candidate for the neurological phenotypes of the 12q15 microdeletion syndrome.

Haploinsufficiency of NCOR1 associated with autism spectrum disorder, scoliosis, and abnormal palatogenesis.

NCOR1 (nuclear receptor corepressor 1) is a transcriptional coregulatory protein that regulates the balance between histone acetylation and histone deacetylation. NCOR1 is listed as one of the 3,230 dose-sensitive genes which very rarely show truncating mutations in the pediatric population without severe diseases, even in a heterozygous state. In a large cohort study of intellectual disability/autism spectrum disorder, splicing mutations were identified in two individuals, however, the truncating effects of these splicing mutations have not been examined at the transcription level. We describe a 3-year-old girl who had behavior consistent with autism spectrum disorder, a bifid uvula, and early-onset scoliosis. Trio exome analysis showed a de novo heterozygous mutation at the splice donor site in exon 19 of NCOR1, c.2182 + 1G > T (NM_00190440.1). Reverse transcription polymerase chain reaction assay confirmed that the splicing mutation results in skipping of exon 19, a shift in the reading frame and then to nonsense-mediated mRNA decay. This patient represents the first patient who has had unequivocal documentation of haploinsufficient for the NCOR1 gene. Based on our observations, we conclude that NCOR1 is indeed a human disease-causing gene. We further suggest that bifid uvula, a micro form of cleft palate, may well be causally related to de novo NCOR1 haploinsufficiency, in that a previously reported deletion mapping study of atypical Smith-Magenis syndrome patients with large deletions and cleft palate identified that NCOR1, the only loss-of-function-intolerant gene within the region, is located in the smallest region of overlap.

Further evidence that a blepharophimosis syndrome phenotype is associated with a specific class of mutation in the ADNP gene.

Heterozygous truncating mutations in ADNP are associated with a syndromic form of intellectual disability known as Helsmoortel-van der Aa syndrome. Among 17 previously reported patients with Helsmoortel-van der Aa syndrome, one patient exhibited blepharophimosis. Whether blepharophimosis represents a phenotypic expression of the ADNP mutation spectrum or a chance association remains unclear. Herein, we report another patient with a de novo truncating mutation in ADNP who exhibited a combination of blepharophimosis and epicanthal folds. In our retrospective re-evaluation of six originally reported patients whose facial photographs were available, at least one patient indeed had blepharophimosis and epicanthal folds. Furthermore, all three patients with blepharophimosis and epicanthal folds, including the presently reported patient, had truncating mutations at the same specific portion of the protein, that is the bipartite nuclear localization signal. We suggest that this specific class of ADNP mutation is likely associated with a blepharophimosis syndrome phenotype. From a clinical standpoint, a differential diagnosis of patients with blepharophimosis should include ADNP mutations in addition to blepharophimosis ptosis epicanthus inversus syndrome, especially when intellectual disability is present.

[Irreversible cerebral ischemia caused by febrile status epilepticus in Sturge-Weber syndrome type III].

We report a 9-year-old girl with Sturge-Weber syndrome (SWS) type III, whose motor function deteriorated after an episode of febrile status epilepticus. The patient had leptomeningeal angiomas in the left temporal, occipital, and parietal lobes. Complex partial seizures, which started at 8 months, were controlled by antiepileptic medications. At 9 years of age, she developed irreversible ischemic lesions in the left temporal and occipital regions after the febrile status epilepticus and her motor function deteriorated. In addition to antiepileptic medications, aspirin therapy was started.SWS type III is a rare disorder characterized by leptomeningeal angiomatosis without facial nevus. In addition to the chronic ischemia in the affected cortex, epileptic seizures result in a phased progression of ischemia in SWS. Although the patient's complex partial seizures had been well-controlled, a single episode of febrile status epilepticus resulted in permanent brain lesions. The impairment of appropriate hemodynamic response to status epilepticus, together with venous hypertension in the affected side in SWS may have caused the cerebral infarction in our case. Seizure control is crucial to improving the neurological prognosis of SWS.

Hirschsprung disease as a yet undescribed phenotype in a patient with ARID1B mutation.

Mutations in the BAF complex (mammalian SWI/SNF complex) are responsible for Coffin-Siris syndrome, which is characterized by developmental delay, distinctive facial features, hirsutism, and hypoplasia/aplasia of the fifth finger/fingernails. Hirschsprung disease is characterized by defective stem cells in the enteric neural system, and the involvement of multiple signaling cascades has been implicated. So far, the roles of the BAF complex in the genesis of Hirschsprung disease have remained unknown. Here, we document a patient with coarse facial features, postnatal growth failure, developmental delay, epilepsy, and hypoplasia of the corpus callosum and cerebellum but without a hypoplastic fifth finger/fingernail. In addition, he had Hirschsprung disease. Exome sequencing with a gene set representing a total of 4,813 genes with known relationships to human diseases revealed a heterozygous frameshift mutation in ARID1B (c.5789delC p.Pro1930Leufs*44). The presence of a congenital cataract and Hirschsprung disease in the presently reported patient further expands the phenotypic spectrum of patients with ARID1B mutations and may suggest the potential role of the BAF complex in the pathogenesis of the enteric neural system. The present observation is in agreement with a recent study of Drosophila neuroblasts showing that the dysregulated BAF complex leads to an abnormal lineage progression of neural stem cell lineages and that Hirschsprung disease is caused by abnormal stem cell lineages in the peripheral neural tissues. © 2016 Wiley Periodicals, Inc.