A Brain Morphometry Study with Across-Site Harmonization Using a ComBat-Generalized Additive Model in Children and Adolescents

Regional anatomical structures of the brain are intimately connected to functions corresponding to specific regions and the temporospatial pattern of genetic expression and their functions from the fetal period to old age. Therefore, quantitative brain morphometry has often been employed in neuroscience investigations, while controlling for the scanner effect of the scanner is a critical issue for ensuring accuracy in brain morphometric studies of rare orphan diseases due to the lack of normal reference values available for multicenter studies. This study aimed to provide across-site normal reference values of global and regional brain volumes for each sex and age group in children and adolescents. We collected magnetic resonance imaging (MRI) examinations of 846 neurotypical participants aged 6.0-17.9 years (339 male and 507 female participants) from 5 institutions comprising healthy volunteers or neurotypical patients without neurological disorders, neuropsychological disorders, or epilepsy. Regional-based analysis using the CIVET 2.1.0. pipeline provided regional brain volumes, and the measurements were across-site combined using ComBat-GAM harmonization. The normal reference values of global and regional brain volumes and lateral indices in our study could be helpful for evaluating the characteristics of the brain morphology of each individual in a clinical setting and investigating the brain morphology of ultra-rare diseases.

Neuroimaging in acute infection-triggered encephalopathy syndromes

Acute encephalopathy associated with infectious diseases occurs frequently in Japanese children (400-700 children/year) and is the most common in infants aged 0-3 years. Acute encephalopathy is classified into several clinicoradiological syndromes; acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is the most common subtype, followed by clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) and acute necrotizing encephalopathy (ANE). Neuroimaging, especially magnetic resonance imaging (MRI), is useful for the diagnosis, assessment of treatment efficacy, and evaluation of the pathophysiology of encephalopathy syndromes. MRI findings essential for diagnosis include delayed subcortical reduced diffusion (bright tree appearance) for AESD, reversible splenial lesions with homogeneously reduced diffusion for MERS, and symmetric hemorrhagic thalamic lesions for ANE. We reviewed several MRI techniques that have been applied in recent years, including diffusion-weighted imaging for the characterization of cerebral edema, arterial spin labeling for evaluating cerebral perfusion, and magnetic resonance spectroscopy for evaluating metabolic abnormality.

A case of early-infantile onset, rapidly progressive leukoencephalopathy with calcifications and cysts caused by biallelic SNORD118 variants

Leukoencephalopathy with calcifications and cysts is a rare autosomal recessive genetic disorder neuroradiologically characterized by intracranial calcification, cerebral white matter disease, and multiple cysts. Although SNORD118 genes have recently been identified as a cause of this disorder, its clinical course varies for each patient. We report an early infantile case of this disease that progressed rapidly with confirmed SNORD118 variants. A 3-month-old female infant presented with epileptic seizures. Computed tomography revealed intracranial calcifications in the basal ganglia and thalamus. Magnetic resonance imaging demonstrated hyperintense lesions in the diffuse white matter on T2-weighted images starting at 7 months of age. Calcifications developed in the cerebral white matter, pons, and cerebellum. Small cysts appeared in the cerebral white matter at 1 year and 6 months. These cysts then began to increase bilaterally and expand rapidly. Although her epilepsy was controlled, she exhibited severe developmental delays and was unable to speak or walk at the age of 4 years. Whole-exome sequencing did not reveal any causal variants in the coding sequences. Further, Sanger sequencing revealed biallelic SNORD118 variants. Clinical features of this disease have not been established. To date, no cases with rapid changes in imaging results have been reported in detail prior to the appearance of cysts. Thus, we report a novel case that had an early infantile-onset and progressed rapidly with sequential appearance of calcification, white matter lesions and cysts. As SNORD118 variants might be missed by regular whole-exome sequencing, careful neuroimaging follow-up may be necessary to diagnose this disease.

Multimodal MR imaging in acute exacerbation of methylmalonic acidemia

Methylmalonic acidemia (MMA) is a disorder of methylmalonic acid metabolism caused by impaired methylmalonyl CoA mutase. Neuroimaging shows symmetric hypodensity on CT, and T2 prolongation on MRI in the globus pallidus; however, there have been only a few reports on MR spectroscopy findings and no previous reports on arterial spin labeling (ASL), both of which could reflect neurochemical derangement in MMA. We herein report an 18-month-old Sri Lankan boy presented with severe acute exacerbation of MMA due to bacteremia of Salmonella sp. O7. MRI on the seventh day showed T1 and T2 prolongation with decreased diffusion in the bilateral globus pallidus. ASL revealed hyperperfusion in the bilateral globus pallidus. MR spectroscopy showed increased choline (Cho), myo-inositol (mIns), glutamine (Gln), and lactate (Lac) in the globus pallidus; and increased Gln and Lac in the white matter. The globus pallidus is the site of high energy demand around the age of 1 year. In severe acute exacerbation of MMA, increased anaerobic metabolism due to impaired mitochondrial function may lead to hyperperfusion in the globus pallidus to compensate for a disturbed energy supply. Increased Cho, mIns, and Lac in the globus pallidus may result from active demyelination, astrogliosis, and increased anaerobic metabolism. Increased Gln in the basal ganglia and white matter may reflect excitotoxicity.

2000. Clinical characteristics and prognosis of patients with Shiga toxin-producing Escherichia coli hemolytic uremic syndrome and encephalopathy: a nationwide observational study in Japan

Background

Shiga toxin-producing Escherichia coli (STEC) may cause hemolytic uremic syndrome (STEC-HUS) and encephalopathy which possibly lead to neurological sequelae and mortality. However, the detailed epidemiology of this disease remains unclear due to its low frequency. This study aimed to describe the characteristics, demographics, and mortality of patients with STEC-HUS using a nationwide database.

Methods

We performed a retrospective cohort study using the Diagnosis Procedure Combination database, which includes approximately half of acute-care inpatients across Japan. We enrolled patients who were hospitalized for STEC-HUS from July 2010 to March 2020. We defined patients with unfavorable outcomes as any of the following at discharge: in-hospital death within three months, tracheostomy, mechanical ventilation, dialysis, and rehabilitation.

Results

This study included 655 patients with STEC-HUS (median age, 7 years). 62 patients (9.5%) were admitted to intensive care units within 2 days of admission. A total of 125 (19.1%) patients had any one of the composite unfavorable outcomes: 24 (3.7%) in-hospital death within 3 months, 9 (1.4%) tracheostomy during hospitalization, 24 (3.7%) mechanical ventilation at discharge, 22 (3.4%) dialysis at discharge, and 95 (14.5%) rehabilitation at discharge. Thirty-one patients (4.7%) developed STEC-HUS related acute encephalopathy.

Conclusion

Regardless of advances in multidisciplinary medicine, we found STEC-HUS remains a poor prognostic condition.

Disclosures

All Authors: No reported disclosures.

A child with mitochondrial DNA deletion presenting diabetes mellitus as an initial symptom

Children with mitochondrial disease may present with diabetes mellitus (DM) without autoimmune antibodies as an initial manifestation, however, it is difficult to make a precise diagnosis in early stages. We present a 2-year-old male patient with mitochondrial disease who showed insulin-dependent DM without autoimmune antibodies as an initial symptom. He later presented with progressive motor deterioration, hearing disability, ptosis, external ophthalmoplegia, and retinitis pigmentosa at 6 years and 6 months. T2- and diffusion-weighted imaging revealed high signal lesions in the subcortical white matter, anterior thalamus, globus pallidus, and brainstem. MR spectroscopy showed elevated lactate and low N-acetylaspartate in the affected white matter. Genetic analysis revealed a single large-scale mitochondrial DNA deletion at 7117-13994, leading to a diagnosis of mitochondrial DNA deletion syndrome associated with insulin-dependent DM. Although the frequency of DM in pediatric mitochondrial disease is low, mitochondrial disease, especially due to mitochondrial DNA deletion, should be considered as a differential diagnosis in those with insulin-dependent DM without autoimmune antibodies, and MRI and MR spectroscopy are recommended for an early diagnosis.

Kawasaki Disease Shock Syndrome in Japan and Comparison With Multisystem Inflammatory Syndrome in Children in European countries

Multisystem inflammatory syndrome in children (MIS-C) is a severe Kawasaki-like illness that was first linked to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in European countries in the spring of 2020 and has been suggested to have overlap with Kawasaki disease shock syndrome (KDSS). There are few reports of MIS-C from Asia. This observational study aimed to identify the clinical features in children presenting with KDSS in Japan over a 5-year period and to summarize similarities and differences between KDSS and MIS-C. We retrospectively collected data on patient characteristics, clinical signs and symptoms, treatment, and prognosis including coronary artery abnormalities (CAAs), which were compared with data of patients with KDSS worldwide and patients with MIS-C from a review. KDSS was identified in 6 (1.1%) of 552 patients with Kawasaki disease (KD) treated at a single institution in Japan between 2015 and 2020 (1 in 2020). In patients with KDSS in Japan or worldwide vs. patients with MIS-C, KDSS was more likely to have a diagnosis of complete KD (100, 70 vs. 6.3%), a higher incidence of CAAs (50, 65 vs. 11%), and a greater requirement for vasoactive agonists (67, 67 vs. 43%) because of circulatory shock (100, 50 vs. 26%). Both KDSS and MIS-C had good prognosis (mortality 0, 6.7 vs. 1.7%). Although KDSS in Japan and MIS-C show some overlap in clinical symptoms, they are unlikely to be the same disease entity. KDSS is more likely to have a cardiovascular phenotype with CAAs and requires treatment with cardiovascular agents.

A case of de novo splice site variant in SLC35A2 showing developmental delays, spastic paraplegia, and delayed myelination

Background

Congenital disorders of glycosylation (CDGs) are genetic diseases caused by pathogenic variants of genes involved in protein or lipid glycosylation. De novo variants in the SLC35A2 gene, which encodes a UDP‐galactose transporter, are responsible for CDGs with an X‐linked dominant manner. Common symptoms related to SLC35A2 variants include epilepsy, psychomotor developmental delay, hypotonia, abnormal facial and skeletal features, and various magnetic resonance imaging (MRI) findings.

Methods

Whole‐exome sequencing was performed on the patient's DNA, and candidate variants were confirmed by Sanger sequencing. cDNA analysis was performed to assess the effect of the splice site variant using peripheral leukocytes. The X‐chromosome inactivation pattern was studied using the human androgen receptor assay.

Results

We identified a de novo splice site variant in SLC35A2 (NM_005660.2: c.274+1G>A) in a female patient who showed severe developmental delay, spastic paraplegia, mild cerebral atrophy, and delayed myelination on MRI, but no seizures. The variant led to an aberrant splicing resulting in an in‐frame 33‐bp insertion, which caused an 11‐amino acid insertion in the presumptive cytoplasmic loop. X‐inactivation pattern was random. Partial loss of galactose and sialic acid of the N‐linked glycans of serum transferrin was observed.

Conclusion

This case would expand the phenotypic spectrum of SLC35A2‐related disorders to delayed myelination with spasticity and no seizures.

Comprehensive investigation of CASK mutations and other genetic etiologies in 41 patients with intellectual disability and microcephaly with pontine and cerebellar hypoplasia (MICPCH)

The CASK gene (Xp11.4) is highly expressed in the mammalian nervous system and plays several roles in neural development and synaptic function. Loss-of-function mutations of CASK are associated with intellectual disability and microcephaly with pontine and cerebellar hypoplasia (MICPCH), especially in females. Here, we present a comprehensive investigation of 41 MICPCH patients, analyzed by mutational search of CASK and screening of candidate genes using an SNP array, targeted resequencing and whole-exome sequencing (WES). In total, we identified causative or candidate genomic aberrations in 37 of the 41 cases (90.2%). CASK aberrations including a rare mosaic mutation in a male patient, were found in 32 cases, and a mutation in ITPR1, another known gene in which mutations are causative for MICPCH, was found in one case. We also found aberrations involving genes other than CASK, such as HDAC2, MARCKS, and possibly HS3ST5, which may be associated with MICPCH. Moreover, the targeted resequencing screening detected heterozygous variants in RELN in two cases, of uncertain pathogenicity, and WES analysis suggested that concurrent mutations of both DYNC1H1 and DCTN1 in one case could lead to MICPCH. Our results not only identified the etiology of MICPCH in nearly all the investigated patients but also suggest that MICPCH is a genetically heterogeneous condition, in which CASK inactivating mutations appear to account for the majority of cases.

Neurochemistry of Hypomyelination Investigated with MR Spectroscopy

Proton magnetic resonance spectroscopy (MRS) allows the noninvasive exploration of tissue metabolism in vivo, providing neurophysiological and neurochemical information. N-acetylaspartate (NAA) is generally considered to be a marker of neurons and axons, and many neurodegenerative disorders, including demyelinating disorders, exhibit a decrease in total NAA (tNAA). MRS in human hypomyelination disorders, such as Pelizaeus-Merzbacher disease (PMD), is characterized by normal to elevated tNAA, elevated myo-inositol and creatine (Cr), and normal to decreased choline (Cho). MRS in the thalamus of a hypomyelinating mouse model, a myelin synthesis-deficient (msd) mouse, a model of connatal PMD with mutation of the Plp1 gene, revealed increased tNAA and Cr and decreased Cho. That of a shiverer mouse with an autosomal recessive mutation of the Mbp gene showed decreased Cho with normal tNAA and Cr. Accordingly, the reduction of Cho on MRS might be a common marker for hypomyelinating disorders. tNAA concentrations range from normal to increased, probably depending upon the underlying pathology of oligodendrocytes. tNAA may be increased in hypomyelination with a reduced number of mature oligodendrocytes, such as PMD.

Diffusion-weighted MRI for early diagnosis of neonatal herpes simplex encephalitis

AIM

To determine the early changes and evolutions of brain diffusion-weighted imaging (DWI), and analyze prognostic factors of the early changes among patients with neonatal herpes simplex encephalitis (NHSE).

METHOD

We selected patients who developed encephalitis by 28 d after birth; had herpes simplex infection; and who underwent magnetic resonance imaging, including DWI, ⩽7 d of symptom onset. Thirty-two DWI scans between 0 and 28 d after onset in 13 patients and the clinical data were recruited. The distribution, evolution of the lesions, and neurological outcome were analyzed.

RESULTS

DWI frequently showed multiple cortical lesions in both hemispheres in the early period and both hemispheres on DWI (8/9 scans at ⩽48 h, 7/7 patients). As time from onset increased, the cortical lesions tended to coincide with subcortical white matter lesions beneath the initial cortical lesions (p<0.01). Lesions from the cortex extended to the subcortical white matter in 7 patients. Deep cerebral lesions, involving basal ganglia, internal capsules, thalamus, were also found in 9 patients ⩽7 d of onset. The distributions of deep cerebral lesions (none/unilateral/bilateral) ⩽7 d of onset showed significant correlations with neurological prognoses (gross motor functions: p<0.01; developmental or intellectual quotient scores: p<0.01).

INTERPRETATION

Cortical lesions were main findings of DWI in NHSE in the early period. Bilateral deep cerebral lesions ⩽7 d were highly indicative of poor motor and cognitive outcomes.

Serum and CSF biomarkers in acute pediatric neurological disorders

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.

[MRI and CT in the diagnosis of epilepsy]

MRI and CT are important for the diagnosis and treatment of epilepsy. Diffusion-weighted images are particularly useful for detecting early changes in the brain. In this article, I reviewed radiological findings associated with seizures (reduced diffusion and swelling of hippocampus and cortex, and a reversible splenial lesion), and lesions causing epilepsy and seizures, such as congenital abnormality of the brain (holoprosencephaly, hemimegalencephaly, lissencephaly, heterotopia, polymicrogyria, schizencephaly, and focal cortical dysplasia), neurocutaneous syndromes (tuberous sclerosis and Sturge-Weber syndrome), vascular disorders (moyamoya disease/syndrome and cavernous angioma), and encephalitis/encephalopathy (herpes encephalitis, anti-NMDA receptor encephalitis, acute necrotizing encephalopathy of childhood, and acute encephalopathy with biphasic seizures and late reduced diffusion).

Different patterns of cerebellar abnormality and hypomyelination between POLR3A and POLR3B mutations

BACKGROUND

Mutations of POLR3A and POLR3B have been reported to cause several allelic hypomyelinating disorders, including hypomyelination with hypogonadotropic hypogonadism and hypodontia (4H syndrome).

PATIENTS AND METHODS

To clarify the difference in MRI between the two genotypes, we reviewed MRI in three patients with POLR3B mutations, and three with POLR3A mutations.

RESULTS

Though small cerebellar hemispheres and vermis are common MRI findings with both types of mutations, MRI in patients with POLR3B mutations revealed smaller cerebellar structures, especially vermis, than those in POLR3A mutations. MRI also showed milder hypomyelination in patients with POLR3B mutations than those with POLR3A mutations, which might explain milder clinical manifestations.

CONCLUSIONS

MRI findings are distinct between patients with POLR3A and 3B mutations, and can provide important clues for the diagnosis, as these patients sometimes have no clinical symptoms suggesting 4H syndrome.

Clinical and radiologic features of encephalopathy during 2011 E coli O111 outbreak in Japan

OBJECTIVE

To elucidate the clinical and radiologic features and analyze factors associated with neurologic outcomes of encephalopathy secondary to Shiga toxin-producing Escherichia coli (STEC) O111.

METHODS

We reviewed medical records and neuroimaging in 22 patients with neurologic symptoms among 86 with STEC O111 infection.

RESULTS

Twenty-one (6 males and 15 females, 10 children and 11 adults) of the 22 patients were diagnosed with encephalopathy. All patients with encephalopathy also presented with hemolytic-uremic syndrome. Five patients died, from day 1 to 6 months (days 1-5 in 4 patients), due to progressive encephalopathy with severe cerebral edema observed in neuroimaging (4 patients). Fifteen of the 16 surviving patients clinically recovered completely. Statistical analysis revealed differences between patients with poor (n = 6) and good (n = 15) outcomes in the interval from hemolytic-uremic syndrome presentation to encephalopathy, creatinine levels, and the methylprednisolone administration ratio.

CONCLUSION

We note a high incidence of encephalopathy in the Toyama STEC O111 outbreak. All fatal cases resulted from progressive encephalopathy. Methylprednisolone pulse therapy represents a possible therapeutic choice.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that methylprednisolone pulse therapy increases the probability of a good outcome for patients with encephalopathy associated with STEC O111.

MR spectroscopy in 18q(-) syndrome suggesting other than hypomyelination

We reported a 5-year-old boy with 18q(-) syndrome who showed typical magnetic resonance imaging (MRI) findings of high signal intensity on T2-weighted imaging, and a slightly high but lower than normal signal on T1-weighted imaging of the white matter. MR spectroscopy (MRS) revealed increased concentrations of creatine, myoinositol and choline with a normal N-acetylaspartate one. The cerebral white matter lesions observed on MRI in patients with 18q(-) syndrome have been considered to reflect hypomyelination due to a decrease in myelin basic protein so far, however, MRS suggested reactive astrocytic gliosis and accelerated myelin turnover, which are compatible with recent pathological reports of 18q(-) syndrome.

MLL2 and KDM6A mutations in patients with Kabuki syndrome

Kabuki syndrome is a congenital anomaly syndrome characterized by developmental delay, intellectual disability, specific facial features including long palpebral fissures and ectropion of the lateral third of the lower eyelids, prominent digit pads, and skeletal and visceral abnormalities. Mutations in MLL2 and KDM6A cause Kabuki syndrome. We screened 81 individuals with Kabuki syndrome for mutations in these genes by conventional methods (n = 58) and/or targeted resequencing (n = 45) or whole exome sequencing (n = 5). We identified a mutation in MLL2 or KDM6A in 50 (61.7%) and 5 (6.2%) cases, respectively. Thirty-five MLL2 mutations and two KDM6A mutations were novel. Non-protein truncating-type MLL2 mutations were mainly located around functional domains, while truncating-type mutations were scattered through the entire coding region. The facial features of patients in the MLL2 truncating-type mutation group were typical based on those of the 10 originally reported patients with Kabuki syndrome; those of the other groups were less typical. High arched eyebrows, short fifth finger, and hypotonia in infancy were more frequent in the MLL2 mutation group than in the KDM6A mutation group. Short stature and postnatal growth retardation were observed in all individuals with KDM6A mutations, but in only half of the group with MLL2 mutations.

A child with three episodes of reversible splenial lesion

In this study, we report the case of an 8-year-old girl who had three episodes of reversible splenial lesion of the corpus callosum (SCC) in 2 years. Vomiting, hypoglycemia, and fever were followed by altered consciousness and diminished muscle tone. In each episode, the clinical manifestations and abnormalities detected during magnetic resonance imaging resolved in 2 weeks. Transient alteration of vision and spike discharges revealed by interictal electroencephalogram implied the SCC lesions were related to epileptic activities. At follow-up, the patient had not presented with SCC lesions or altered consciousness for more than 4 years after undergoing carbamazepine treatment. Our case is the first report of a patient who presented with three episodes of reversible splenial lesion.

ADORA2A polymorphism predisposes children to encephalopathy with febrile status epilepticus

OBJECTIVE

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is a childhood encephalopathy following severe febrile seizures, leaving neurologic sequelae in many patients. However, its pathogenesis remains unclear. In this study, we clarified that genetic variation in the adenosine A2A receptor (ADORA2A), whose activation is involved in excitotoxicity, may be a predisposing factor of AESD.

METHODS

We analyzed 4 ADORA2A single nucleotide polymorphisms in 85 patients with AESD. The mRNA expression in brain samples, mRNA and protein expression in lymphoblasts, as well as the production of cyclic adenosine monophosphate (cAMP) by lymphoblasts in response to adenosine were compared among ADORA2A diplotypes.

RESULTS

Four single nucleotide polymorphisms were completely linked, which resulted in 2 haplotypes, A and B. Haplotype A (C at rs2298383, T at rs5751876, deletion at rs35320474, and C at rs4822492) frequency in patients was significantly higher than in controls (p = 0.005). Homozygous haplotype A (AA diplotype) had a higher risk of developing AESD (odds ratio 2.32, 95% confidence interval 1.32-4.08; p = 0.003) via a recessive model. mRNA expression was significantly higher in AA than AB and BB diplotypes, both in the brain (p = 0.003 and 0.002, respectively) and lymphoblasts (p = 0.035 and 0.003, respectively). In lymphoblasts, ADORA2A protein expression (p = 0.024), as well as cellular cAMP production (p = 0.0006), was significantly higher in AA than BB diplotype.

CONCLUSIONS

AA diplotype of ADORA2A is associated with AESD and may alter the intracellular adenosine/cAMP cascade, thereby promoting seizures and excitotoxic brain damage in patients.

Whole-exome sequencing of a unique brain malformation with periventricular heterotopia, cingulate polymicrogyria and midbrain tectal hyperplasia

We report a case of an infant with unique and unreported combinations of brain anomalies. The patient showed distinctive facial findings, severe delay in psychomotor development, cranial nerve palsy and seizures. Brain magnetic resonance imaging performed at 5 days of age revealed complex brain malformations, including heterotopia around the mesial wall of lateral ventricles, dysmorphic cingulate gyrus, and enlarged midbrain tectum. The patient unexpectedly died at 13 months of age. Postmortem pathological findings included a polymicrogyric cingulate cortex, periventricular nodular heterotopia, basal ganglia and thalamic anomalies, and dysmorphic midbrain tectum. Potential candidate genes showed no abnormalities by traditional PCR-based sequencing. Whole-exome sequencing confirmed the presence of novel gene variants for filamin B (FLNB), guanylate binding protein family member 6, and chromosome X open reading frame 59, which adapt to the autosomal recessive mode or X-linked recessive mode. Although immunohistochemical analysis confirmed the expression of FLNB protein in the vessel walls and white matter in autopsied specimens, there may be functional relevance of the compound heterozygous FLNB variants during brain development.

Clinical and radiological features of Japanese patients with a severe phenotype due to CASK mutations

Heterozygous loss of function mutations of CASK at Xp11.4 in females cause severe intellectual disability (ID) and microcephaly with pontine and cerebellar hypoplasia (MICPCH). However, the longitudinal clinical and radiological course of affected patients, including patterns of postnatal growth, has not been described. Neurodevelopmental and imaging information was retrospectively accrued for 16 Japanese (15 female and 1 male) patients with ID and MICPCH associated with CASK mutations. All records were analyzed; patient age ranged from 2 to 16 years at the time of the most recent examinations. The growth pattern, neurological development, neurological signs/symptoms, and facial features were similar in the 15 female patients. Their head circumference at birth was within the normal range in about half, and their height and weight were frequently normal. This was followed by early development of severe microcephaly and postnatal growth retardation. The patients acquired head control almost normally between 3 and 6 months, followed by motor delay. More than half of the female patients had epilepsy. Their MRIs showed microcephaly, brainstem, and cerebellar hypoplasia in early infancy, and a normal or large appearing corpus callosum. The male patient showed a more severe clinical phenotype. These uniform clinical and radiological features should facilitate an early diagnosis and be useful for medical care of females with ID and MICPCH associated with CASK mutations.

A severe form of epidermal nevus syndrome associated with brainstem and cerebellar malformations and neonatal medulloblastoma

Here we report a boy with epidermal nevus syndrome associated with brainstem and cerebellar malformations and neonatal medulloblastoma. The patient had epidermal nevi and complicated brain malformations including macrocephaly with polymicrogyria, dysmorphic and enlarged midbrain tectum, enlarged cerebellar hemispheres with small and maloriented folia. The patient died after surgical resection of medulloblastoma which was newly recognized on MRI at 51 days of age. Postmortem pathological examinations showed very unique and bizarre malformation of the midbrain and hindbrain. The cerebellar cortex exhibited a coarse, irregular and bumpy surface, blurred border between the Purkinje cell layer and internal granule cell layer, and many foci of heterotopia in the cerebellar white matter. The brainstem showed multiple anomalies, including enlargement of superior colliculi, hypoplasia of pyramidal tracts and dysplasia of inferior olivary nuclei. The unusual constellation of brain malformations of our patient will widen the spectrum of epidermal nevus syndrome.

Late delirious behavior with 2009 H1N1 influenza: mild autoimmune-mediated encephalitis?

Delirious behavior associated with influenza usually has an onset within a few days after fever and lasts <24 hours. As we encountered several patients with 2009 H1N1 influenza who presented with late-onset and long-standing delirious behavior, we retrospectively evaluated the clinical, radiologic, and laboratory features to elucidate the possible pathophysiology. This information was collected on 5 previously healthy patients (2 boys and 3 girls, aged 10-15 years) with 2009 H1N1 influenza who presented with late onset (>3 days after fever) and long-standing (>48 hours) delirious behavior. Each exhibited mild to moderate drowsiness between the episodes of delirious behavior. Electroencephalography was normal except for 1 patient with high voltage and slow activity bilaterally in the occipital regions. Brain MRI was normal. The outcome was excellent with no neurologic sequel in 4 of the 5 patients. In all 5 patients, autoantibodies against N-methyl-D-aspartate type glutamate receptor were elevated or positive in cerebrospinal fluid or serum; the autoantibody levels normalized in the 3 patients who had follow-up studies. This study indicates that 2009 H1N1 influenza has a tendency to cause late-onset and long-standing delirious behavior, at least in Japanese children. Mild autoimmune-mediated encephalitis should be considered as an underlying cause.

[Congenital cerebral hypomyelination---Pelizaeus-Merzbacher disease and associated disorders]

Congenital cerebral hypomyelination includes a group of genetic disorders, such as Pelizaeus-Merzbacher disease (PMD), and is characterized by hypomyelination of the cerebral white matter. Until recently, no classification system was available for congenital hypomyelination disorders that are clinically and genetically excluded for PMD. However, the establishment of new disease entities with gene discoveries has generated a clinical need for a new classification and diagnostic criteria for this group of disorders. Here, we review the recent findings on congenital cerebral hypomyelination, which includes 11 diseases, with a novel disease classification and diagnostic criteria with flow charts.

Metabolic changes in early childhood using LCModel with corrected water scaling method

PURPOSE

To examine metabolic changes of the brain in early infancy measured by the LCModel with the water scaling method (LCModel-WS), and to determine whether the unsuppressed water signal (UWS) on the MR console and the area of the unsuppressed water peak (AUW) in the LCModel can be used to correct metabolite concentrations.

MATERIALS AND METHODS

MR spectroscopy was performed on a 1.5 Tesla MR scanner. To determine whether UWS and AUW increases linearly with PD and exp(-TE/T2), these values were measured using three phantoms with different PD and T2 values. UWS and AUW were also measured (PRESS, TR = 5000 ms, TE = 30 ms, VOI = 4.5 mL) in 57 pediatric controls (aged 2 weeks to 15 years).

RESULTS

Phantom studies revealed UWS and AUW increases linearly with PD and exp(-TE/T2). UWS and AUW were high in controls younger than 2 years of age, but gradually decreased to become almost constant after 4 years (UWS = 504 × 10(3) , AUW = 2.05 × 10(7)). AUW was linearly proportional to UWS in controls. These indicated that metabolite concentrations should be multiplied by the ratio of UWS/504 × 10(3) or AUW/2.05 × 10(7). Age dependent metabolite concentrations corrected by the ratio were obtained.

CONCLUSION

Both UWS and AUW can be used to correct metabolite concentrations; these corrections can significantly improve quantification of metabolites' concentration in early childhood.

Lesions in the central tegmental tract in autopsy cases of developmental brain disorders

We retrospectively analyzed central tegmental tract (CTT) lesions in 120 consecutive autopsy cases of developmental brain disorders to investigate the significance of symmetrical CTT lesions. Magnetic resonance imaging (MRI) findings of CTT lesions have been sporadically reported in various cases of child neurological diseases. In this study, symmetrical CTT lesions were observed in 25 (20.8%) among 120 cases of developmental brain disorders. These 25 cases were classified into three groups (groups I-III) in decreasing order of the severity of the lesion. Compared to five cases of group I in which CTT lesions were accompanied by diffuse tegmental damage, 20 cases of groups II or III developed relatively selective CTT lesions in which the medial longitudinal fasciculus and/or medial or lateral lemniscus were preserved. The causes of brain disorders in all three groups seemed to be different, and lysosomal disorders and congenital brain anomalies were frequently seen in cases in groups II and III, respectively. The dentato-rubro-olivary system is known to be involved in palatal myoclonus, and five out of 13 cases in group II showed myoclonic epilepsy. Compared with 95 cases without the CTT lesion, the changes in the pontine reticular formation were more closely associated with the CTT lesion than those in the inferior olivary nucleus. In conclusion, in cases of developmental brain disorders, the neuropathology of the symmetrical CTT lesion should be investigated.

Molecular analysis of TSC2/PKD1 contiguous gene deletion syndrome

BACKGROUND

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder caused by mutations in either of two genes, TSC1 and TSC2. Autosomal dominant polycystic kidney disease (ADPKD) is caused by mutations in either PKD1 or PKD2. TSC2 lies immediately adjacent to PKD1 and large heterozygous deletions can result in the TSC2/PKD1 contiguous gene syndrome (PKDTS). PKDTS has been identified in patients with TSC and early-onset severe ADPKD. However, genetic diagnosis with conventional methods proved to be difficult because its genetic aberrations are large monoallelic mutations.

METHODS

In the study presented here, we used both multiplex ligation-dependent probe amplification (MLPA) and array comparative genomic hybridization (array-CGH) for four PKDTS patients.

RESULTS

We were able to detect large heterozygous deletions including TSC2 and PKD1 by both of MLPA and array-CGH in all four patients. And in two patients, array-CGH identified relatively large genomic aberrations (RAB26, NTHL1, etc.), that extended outside of TSC2 or PKD1.

CONCLUSION

The identical results obtained with these two completely different methods show that both constitute highly reliable strategies. Only a few studies have determined the breakpoints of large deletions in this disease and ours is the first to have identified the breakpoints by using array-CGH. We suggest that these methods are not only useful for the diagnosis of PKDTS but also for elucidation of its molecular mechanism.

Genetic diagnosis and acetazolamide treatment of familial hemiplegic migraine

A female patient presented with horizontal gaze nystagmus, mild cerebellar ataxia, recurrent headache and hemiplegia since childhood with cerebellar atrophy on magnetic resonance imaging. Genetic analysis revealed a CACNA1A gene mutation, leading to a diagnosis of familial hemiplegic migraine (FHM1). FHM is very rare, but should be considered as a differential diagnosis for childhood cerebellar symptoms and/or cerebellar atrophy. To avoid missing FHM1, a detailed clinical history including headache or hemiplegia is essential. Oral acetazolamide during the aura phase, comprising mild headache and abnormal leg sensation, relieved these symptoms in this patient, suggesting that acetazolamide could represent a first line of treatment.

Moyamoya disease in children

Moyamoya disease is an uncommon cerebrovascular disease characterized by progressive steno-occlusive changes in the terminal internal carotid arteries (ICA) and their main branches, associated with the development of moyamoya vessels. The incidence of the disease is high in east Asia, especially in Japan and Korea. The familial form accounts for 10-15%. Moyamoya disease has two age distribution peaks at around 5 and 40years. Most pediatric patients exhibit transient ischemic attacks or infarction. Headache and involuntary movements are serious symptoms associated with pediatric moyamoya disease. MRI and MR angiography (MRA) are useful and non-invasive methods for diagnosing or monitoring moyamoya disease. Cerebral angiography is still the gold standard for a diagnosis, however, it is not mandatory when MRI and MRA show typical findings of moyamoya disease; steno-occlusive changes at the ends of ICA and an abnormal vascular network in the basal ganglia. Other MRI findings have been reported, including T2 shortening in the white matter, the ivy sign on fluid-attenuated inversion recovery (FLAIR) images, and medullary streaks on FLAIR or enhanced T1-weighted images.

[Radiological and EEG findings in acute encephalopathy syndromes in children]

Acute infectious encephalopathy, including influenza associated encephalopathy, is more frequently observed in Japanese infants. MRI is accepted as a more sensitive technique than CT for the diagnosis of encephalopathy. Diffusion weighted images and MR spectroscopy are particularly useful for detecting early changes and metabolic derangements in the brain, respectively. EEG can reflect brain function. In this article, I reviewed radiological and EEG findings in three infectious encephalopathy syndromes, i.e., acute encephalopathy with biphasic seizures and late reduced diffusion (AESD), acute necrotizing encephalopathy of childhood (ANE), and clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS), in which MRI is essential for the diagnosis.

Pontine hypoplasia in 5p-syndrome: A key MRI finding for a diagnosis

A 5-year-old female case of 5p-syndrome exhibited pontine hypoplasia on magnetic resonance imaging. A high-pitched cry characteristic of 5p-syndrome disappeared after 2 years. 5p-syndrome should be considered as a differential diagnosis for brainstem, especially pontine, hypoplasia. Older patients with brainstem hypoplasia should be asked about a history of a high-pitched cry in infancy so as not to miss this syndrome.

The axonal damage marker tau protein in the cerebrospinal fluid is increased in patients with acute encephalopathy with biphasic seizures and late reduced diffusion

Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is a recently clinicoradiologically-established encephalopathy syndrome. In the present study, we examined the levels of cerebrospinal fluid (CSF) tau protein, a marker of axonal damage, in 11 patients with AESD. CSF tau levels were normal on day 1 and increased from day 3 of the disease between the initial and the secondary seizures. Magnetic resonance imaging (MRI) reveals reduced diffusion in the subcortical white matter during days 3-7. Two patients showed elevated tau protein prior to the diffusion abnormality of subcortical white matter on MRI. Levels of CSF neuron specific enolase (NSE), a neuronal marker, were elevated in only two out of seven patients with AESD, and CSF tau levels were also increased in these patients. Our results indicated that tau protein is a more sensitive marker than NSE and axonal damage causes the conspicuous MRI findings in AESD patients. A therapeutic strategy for axonal protection should be developed to prevent severe neurological impairment of AESD patients.

A splenial lesion with transiently reduced diffusion in clinically mild encephalitis is not always reversible: A case report

The MR imaging finding of a reversible splenial lesion with transiently reduced diffusion has been reported in patients with clinically mild encephalitis/encephalopathy, leading to a new clinical-radiological syndrome, clinically mild encephalitis/encephalopathy with a reversible splenial lesion. We recently experienced a 3-year-old boy with clinically mild encephalitis with a splenial lesion exhibiting transient reduced diffusion on admission. He recovered completely with no particular treatment within 2 weeks. Though the splenial lesion decreased in size, it was detected for over 5 months in T2-weighted imaging. It is suggested that a splenial lesion with transiently reduced diffusion in clinically mild encephalitis/encephalopathy is not always reversible, and could result in gliosis.

Diffuse cerebral hypomyelination with cerebellar atrophy and hypoplasia of the corpus callosum

Three unrelated Japanese patients who presented with ataxia and mild mental retardation were examined in this study. Early development was normal in two patients and slightly delayed in one. All could walk independently, but were unstable due to cerebellar ataxia. They had mild intellectual retardation and displayed slow, progressive, and mild clinical courses. Two patients lost the ability to walk at 12 and 25 years of age. Brain MRI of the three patients revealed diffuse cerebral hypomyelination, moderate cerebellar cortical atrophy, and hypoplasia of the corpus callosum, which were seen in other diffuse hypomyelination syndrome. No known abnormalities were found in biochemical and genetic studies. Auditory brainstem responses and nerve conduction studies were normal. A definite diagnosis could not be made because of the lack of hypodontia, hypogonadism, cataracts, or basal ganglia atrophy. Based on common MRI findings and the relatively mild clinical courses, we believe that these patients may have another subset form of diffuse hypomyelination syndrome involving the cerebral white matter and cerebellum.

Two newly proposed infectious encephalitis/encephalopathy syndromes

Two newly proposed infectious encephalitis/encephalopathy syndromes, in which magnetic resonance imaging (MRI) is essential for the diagnosis, have been reviewed. Acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) is reported only in East Asian infants, characterized by a febrile seizure (usually >30 min) as the initial neurological symptom on day 1, followed by secondary seizures at day 4 to 6; affected children display variable levels of neurological sequelae. MRI shows no acute abnormality during the first two days; reduced diffusion appears in the frontal or fronto-parietal subcortical white matter during days 3 to 9, then disappears between days 9 and 25. Excitotoxic injury with delayed neuronal death is hypothesized as a possible mechanism based on MR spectroscopic findings. Clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) is characterized by a reversible lesion with homogeneously reduced diffusion in the corpus callosum (at least involving the splenium), sometimes associated with symmetrical white matter lesions. The most common neurological symptom is delirious behavior, followed by consciousness disturbance, and seizures, all of which completely recover within a month. The reason for the transiently reduced diffusion within the lesions is unknown; possibilities that have been postulated include intramyelinic edema, interstitial edema in tightly packed fibers, and a transient inflammatory infiltrate.

Homozygous female Becker muscular dystrophy

We report, for the first time, on a female Becker muscular dystrophy (BMD) patient with homozygous dystrophin deletion. The 14-year-old patient, product of consanguineous parents, presented with a 7-year history of exercise intolerance and recurrent myoglobinuria. Although CK was elevated to 1,800 U/L, no muscle weakness, atrophy, or hypertrophy was seen on examination. Muscle pathology demonstrated a minimal dystrophic change and faint dystrophin staining pattern. Semi-quantitative PCR of dystrophin revealed a homozygous dystrophin deletion of exons 45-55, which is predicted to remove 593 amino acids without frame shifting. Western blot analysis of skeletal muscle for dystrophin showed a 306 kDa band; thus, we made a diagnosis of female BMD. We confirmed identical deletion in both father and mother, in hemizygous and heterozygous modes, respectively. Neither female Duchenne muscular dystrophy (DMD) nor BMD due to homozygous dystrophin mutation has ever been identified although female DMD has been found in patients with Turner syndrome or unilateral parental disomy for X chromosome. Our results indicate that dystrophinopathy can also be caused in females by homozygosity, albeit rare.

Delirious behavior in influenza is associated with a reversible splenial lesion

Delirious behavior is one of the main clinical features in patients with clinically mild encephalitis/encephalopathy with a reversible splenial lesion. On the other hand, it has been reported that more than 10% of patients with influenza in Japan develop delirious behavior. Magnetic resonance imaging (MRI) studies in patients with influenza-associated delirious behavior were examined to determine how often a reversible splenial lesion is associated with this symptom. All patients who presented to Kameda Medical Center between November 2007 and March 2008 with delirious behavior associated with influenza were studied using MRI and EEG. Of the 370 patients with influenza, 11 had delirious behavior, lasting for less than 12h. MRI revealed a reversible splenial lesion with homogeneously reduced diffusion in 5 patients. Transient EEG abnormalities (occipital slow waves during wakefulness) were observed in 4 of the 9 patients examined. A reversible splenial lesion with reduced diffusion should be considered as an underlying condition in patients with delirious behavior associated with influenza.

Encephalopathy with a reversible splenial lesion is associated with hyponatremia

We have encountered several patients with clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) associated hyponatremia. In order to better understand this phenomenon, Na levels were evaluated in a series of patients with MERS. Na was 131.8+/-4.1 mmol/l (mean+/-SD, range 121-140) in 30 patients with MERS; 138.3+/-2.7 mmol/l (range 134-144) in age-matched 21 patients with upper respiratory infection; 136.6+/-2.5 mmol/l (range 132-140) in nine patients with other type of encephalopathy; and 136.2+/-2.6 mmol/l (range 132-140) in 17 patients with febrile seizures. Twenty-five of the thirty patients with MERS had Na<136 mmol/l. There were significant differences between the Na levels of patients with MERS and those with other groups. It is not possible, from the clinical perspective, to completely separate MERS from hyponatremic encephalopathy or to rule out hyponatremia as a contributing factor of MERS.

Negative correlation between brain glutathione level and negative symptoms in schizophrenia: a 3T 1H-MRS study

Background

Glutathione (GSH), a major intracellular antioxidant, plays a role in NMDA receptor-mediated neurotransmission, which is involved in the pathophysiology of schizophrenia. In the present study, we aimed to investigate whether GSH levels are altered in the posterior medial frontal cortex of schizophrenic patients. Furthermore, we examined correlations between GSH levels and clinical variables in patients.

Methods and Findings

Twenty schizophrenia patients and 16 age- and gender-matched normal controls were enrolled to examine the levels of GSH in the posterior medial frontal cortex by using 3T SIGNA EXCITE ¹H-MRS with the spectral editing technique, MEGA-PRESS. Clinical variables of patients were assessed by the Global Assessment of Functioning (GAF), Scale for the Assessment of Negative Symptoms (SANS), Brief Psychiatric Rating Scale (BPRS), Drug-Induced Extra-Pyramidal Symptoms Scale (DIEPSS), and five cognitive performance tests (Word Fluency Test, Stroop Test, Trail Making Test, Wisconsin Card Sorting Test and Digit Span Distractibility Test). Levels of GSH in the posterior medial frontal cortex of schizophrenic patients were not different from those of normal controls. However, we found a significant negative correlation between GSH levels and the severity of negative symptoms (SANS total score and negative symptom subscore on BPRS) in patients. There were no correlations between brain GSH levels and scores on any cognitive performance test except Trail Making Test part A.

Conclusion

These results suggest that GSH levels in the posterior medial frontal cortex may be related to negative symptoms in schizophrenic patients. Therefore, agents that increase GSH levels in the brain could be potential therapeutic drugs for negative symptoms in schizophrenia.

The evolving MR imaging appearance of lissencephaly: a case report

MR imaging of a patient with epilepsy and psychomotor retardation at 5 months revealed parieto-occipital pachygyria with almost normal cortical appearance and thickness in the frontal region; this appearance evolved into diffuse pachygyria at 7 years. The change of the MR imaging findings may have resulted from myelination in the intracortical and subcortical fibers. It is important for clinicians to be aware of the longitudinal changes of the cerebral cortex in lissencephaly.