α-L-iduronidase fused with humanized anti-human transferrin receptor antibody (lepunafusp alfa) for mucopolysaccharidosis type I: A phase 1/2 trial

Mucopolysaccharidosis type I (MPS I) causes systemic accumulation of glycosaminoglycans due to a genetic deficiency of α-L-iduronidase (IDUA), which results in progressive systemic symptoms affecting multiple organs, including the central nervous system (CNS). Because the blood-brain barrier (BBB) prevents enzymes from reaching the brain, enzyme replacement therapy is effective only against the somatic symptoms. Hematopoietic stem cell transplantation can address the CNS symptoms, but the risk of complications limits its applicability. We have developed a novel genetically modified protein consisting of IDUA fused with humanized anti-human transferrin receptor antibody (lepunafusp alfa; JR-171), which has been shown in nonclinical studies to be distributed to major organs, including the brain, bringing about systemic reductions in heparan sulfate (HS) and dermatan sulfate concentrations. Subsequently, a first-in-human study was conducted to evaluate the safety, pharmacokinetics, and exploratory efficacy of JR-171 in 18 patients with MPS I. No notable safety issues were observed. Plasma drug concentration increased dose dependently and reached its maximum approximately 4 h after the end of drug administration. Decreased HS in the cerebrospinal fluid suggested successful delivery of JR-171 across the BBB, while suppressed urine and serum concentrations of the substrates indicated that its somatic efficacy was comparable to that of laronidase.

Genetic, electrophysiological, and pathological studies on patients with SCN9A-related pain disorders

BACKGROUND AND AIMS

Voltage-gated sodium channel Nav1.7, encoded by the SCN9A gene, has been linked to diverse painful peripheral neuropathies, represented by the inherited erythromelalgia (EM) and paroxysmal extreme pain disorder (PEPD). The aim of this study was to determine the genetic etiology of patients experiencing neuropathic pain, and shed light on the underlying pathogenesis.

METHODS

We enrolled eight patients presenting with early-onset painful peripheral neuropathies, consisting of six cases exhibiting EM/EM-like disorders and two cases clinically diagnosed with PEPD. We conducted a gene-panel sequencing targeting 18 genes associated with hereditary sensory and/or autonomic neuropathy. We introduced novel SCN9A mutation (F1624S) into a GFP-2A-Nav1.7rNS plasmid, and the constructs were then transiently transfected into HEK293 cells. We characterized both wild-type and F1624S Nav1.7 channels using an automated high-throughput patch-clamp system.

RESULTS

From two patients displaying EM-like/EM phenotypes, we identified two SCN9A mutations, I136V and P1308L. Among two patients diagnosed with PEPD, we found two additional mutations in SCN9A, F1624S (novel) and A1632E. Patch-clamp analysis of Nav1.7-F1624S revealed depolarizing shifts in both steady-state fast inactivation (17.4 mV, p < .001) and slow inactivation (5.5 mV, p < .001), but no effect on channel activation was observed.

INTERPRETATION

Clinical features observed in our patients broaden the phenotypic spectrum of SCN9A-related pain disorders, and the electrophysiological analysis enriches the understanding of genotype-phenotype association caused by Nav1.7 gain-of-function mutations.

Heterogeneity and mitochondrial vulnerability configurate the divergent immunoreactivity of human induced microglia-like cells

Microglia play versatile roles in progression of and protection against neuroinflammatory diseases. Little is known, however, about the mechanisms underlying the diverse reactivity of microglia to inflammatory conditions. We investigated how human induced microglia-like (iMG) cells respond to innate immune ligands. Quantitative PCR showed that poly-I:C and lipopolysaccharide (LPS) activated the expression of IL1B and TNF. Immunoreactivity of iMG did not differ between controls (n = 11) and patients with neuroinflammatory diseases (n = 24). Flow cytometry revealed that CD14high cells expressed interleukin (IL) -1β after LPS treatment. Immunoblotting showed that poly-I:C and LPS differentially activated inflammatory pathways but commonly induced mitochondrial instability and the expression of pyruvate kinase isoform M2 (PKM2). Furthermore, a potent stimulator of PKM2 (DASA-58) alleviated IL-1β production after LPS treatment. These data indicate that heterogeneous cell populations and mitochondrial stability underlie the divergent immunoreactivity of human iMG in environments.

Open-label study to investigate the safety and efficacy of adjunctive perampanel in pediatric patients (aged 4 to <12 years) with inadequately controlled focal-onset seizures: Japanese subgroup analysis

PURPOSE

To evaluate the safety and tolerability of adjunctive perampanel in a Japanese subpopulation of Study 311 (NCT02849626), which was a global, multicenter, open-label, single-arm study of children (aged 4 to <12 years) with inadequately controlled focal-onset seizures (FOS), with or without focal to bilateral tonic-clonic seizures (FBTCS) or generalized tonic-clonic seizures (GTCS).

METHODS

Study 311 comprised a Core Study, Extension A, and Extension B; this report focuses on the Japanese patient subgroup in the Core Study only. In the Core Study, Japanese patients (FOS only) received adjunctive perampanel ≤12 mg/day in a 23-week Treatment Phase. Endpoints included safety/tolerability (primary) and median percent change in seizure frequency per 28 days from baseline. Patients were stratified by age and concomitant enzyme-inducing anti-seizure medication (EIASM) use.

RESULTS

Of 65 enrolled Japanese patients, 56 completed the Core Study and nine withdrew. The most common reason for discontinuation was adverse events (AEs) (n = 4 [6.2%]). The mean (standard deviation) daily dose of perampanel in Japanese FOS patients was 5.8 (2.2) mg/day. During the Core Study, treatment-emergent AEs (TEAEs) were reported by 89% of Japanese patients, most commonly nasopharyngitis (28%) and somnolence (28%). The median percent reduction in seizure frequency per 28 days from baseline was 37% and the lower limit of the 95% CI was greater than 10.5%, satisfying the pre-defined efficacy criteria. Perampanel was effective regardless of age or concomitant EIASM use.

CONCLUSION

Perampanel as adjunctive therapy is generally safe, well-tolerated, and efficacious in Japanese children aged 4 to <12 years with FOS (with/without FBTCS).

Long-lasting pain and somatosensory disturbances in children with myelin oligodendrocyte glycoprotein antibody-associated disease

Myelin oligodendrocyte glycoprotein antibody (MOG-Ab) is an autoantibody associated with acquired demyelinating syndrome (ADS) in childhood and adults. The pathogenic roles of MOG-Ab and long-term outcomes of children with MOG-Ab-associated disease (MOGAD) remain elusive. We investigated the clinical features of children with ADS during follow-up in our institute. Clinical data were retrospectively analyzed using medical charts of patients managed in Kyushu University Hospital from January 1st, 2001, to March 31st, 2022. Participants were children of < 18 years of age when they received a diagnosis of ADS in our hospital. Cell-based assays were used to detect MOG-Ab in serum or cerebrospinal fluid at the onset or recurrence of ADS. The clinical and neuroimaging data of MOG-Ab-positive and MOG-Ab-negative patients were statistically analyzed. Among 31 patients enrolled in this study, 22 (13 females, 59%) received tests for MOG antibodies. Thirteen cases (59%) were MOG-Ab-positive and were therefore defined as MOGAD; 9 (41%) were MOG-Ab-negative. There were no differences between MOGAD and MOG-Ab-negative patients in age at onset, sex, diagnostic subcategories, or duration of follow-up. MOGAD patients experienced headache and/or somatosensory symptoms more frequently than MOG-Ab-negative patients (12/13 (92%) vs. 3/9 (22%); p = 0.0066). Somatosensory problems included persistent pain with hyperesthesia in the left toe, perineal dysesthesia, and facial hypesthesia. No specific neuroimaging findings were associated with MOGAD or the presence of somatosensory symptoms.

CONCLUSIONS

Long-lasting somatosensory disturbances are prominent comorbidities in children with MOGAD. Prospective cohorts are required to identify molecular and immunogenetic profiles associated with somatosensory problems in MOGAD.

WHAT IS KNOWN

• Recurrence of demyelinating events occurs in a group of children with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD).

WHAT IS NEW

• Long-lasting headache and somatosensory problems are frequent comorbidities with pediatric MOGAD. Pain and somatosensory problems may persist for more than 5 years. • Neuroimaging data do not indicate specific findings in children with somatic disturbances.

Severe encephalopathy associated with SARS-CoV-2 Omicron BA.1 variant infection in a neonate

INTRODUCTION

The coronavirus disease 2019 (COVID-19), including the Omicron variant, is less severe in children than in adults. To date, there has been no detailed description of COVID-19-associated severe encephalopathy due to the Omicron variant during the neonatal and early infantile periods.

CASE PRESENTATION

During the outbreak of the Omicron variant, a 29-day-old male presented with a pale and ill appearance. The patient was intubated for mechanical ventilation owing to recurrent apnea, which subsequently turned out to be a breath-holding that may have been caused by seizure. In addition, nonconvulsive status epilepticus was observed. Total duration of repetitive seizure activities was approximately 30 min per hour when seizures were most severe. Brain magnetic resonance imaging (MRI) on day 14 revealed extensive hyperintensity in the T2 sequence, hypointensity in the fluid-attenuated inversion recovery (FLAIR) sequence in the deep and subcortical white matter, and diffusion restriction in the corpus callosum. The Omicron BA.1 variant of the severe acute respiratory syndrome coronavirus 2 was detected in his respiratory sample. Follow-up MRI on day 45 revealed multiple cystic cavitations.

CONCLUSION

Although COVID-19 is not severe in most children, life-threatening conditions such as COVID-19-associated severe encephalopathy can occur during the neonatal and early infantile periods.

Interstitial deletions in the proximal regions of 6q: 12 original cases and a literature review

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.

Monogenic causes of pigmentary mosaicism

Pigmentary mosaicism of the Ito type, also known as hypomelanosis of Ito, is a neurocutaneous syndrome considered to be predominantly caused by somatic chromosomal mosaicism. However, a few monogenic causes of pigmentary mosaicism have been recently reported. Eleven unrelated individuals with pigmentary mosaicism (mostly hypopigmented skin) were recruited for this study. Skin punch biopsies of the probands and trio-based blood samples (from probands and both biological parents) were collected, and genomic DNA was extracted and analyzed by exome sequencing. In all patients, plausible monogenic causes were detected with somatic and germline variants identified in five and six patients, respectively. Among the somatic variants, four patients had MTOR variant (36%) and another had an RHOA variant. De novo germline variants in USP9X, TFE3, and KCNQ5 were detected in two, one, and one patients, respectively. A maternally inherited PHF6 variant was detected in one patient with hyperpigmented skin. Compound heterozygous GTF3C5 variants were highlighted as strong candidates in the remaining patient. Exome sequencing, using patients' blood and skin samples is highly recommended as the first choice for detecting causative genetic variants of pigmentary mosaicism.

The clinical characteristics of pediatric coronavirus disease 2019 in 2020 in Japan

BACKGROUND

The COVID-19 pandemic has affected the lives of people of all ages. Most reports on pediatric cases suggest that children experience fewer and milder symptoms than do adults. This is the first nationwide study in Japan focusing on pediatric cases reported by pediatricians, including cases with no or mild symptoms.

METHODS

We analyzed the epidemiological and clinical characteristics and transmission patterns of 840 pediatric (<16 years old) COVID-19 cases reported between February and December 2020 in Japan, using a dedicated database which was maintained voluntarily by members of the Japan Pediatric Society.

RESULTS

Almost half of the patients (47.7%) were asymptomatic, while most of the others presented mild symptoms. At the time of admission or first outpatient clinic visit, 84.0% of the cases were afebrile (<37.5°C). In total, 609 cases (72.5%) were exposed to COVID-19-positive household members. We analyzed the influence of nationwide school closures that were introduced in March 2020 on COVID-19 transmission routes among children in Japan. Transmission within households occurred most frequently, with no significant difference between the periods before and after declaring nationwide school closures (70.9% and 74.5%, respectively).

CONCLUSIONS

COVID-19 symptoms in children are less severe than those in adults. School closure appeared to have a limited effect on transmission. Controlling household transmission from adult family members is the most important measure for prevention of COVID-19 among children.

Incidence and risk factors of acute encephalopathy with biphasic seizures in febrile status epilepticus

OBJECTIVE

To clarify the incidence and risk factors of acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) in pediatric patients with febrile status epilepticus (FSE).

METHODS

We retrospectively surveyed patients with FSE (≥20 min and ≥40 min) who were younger than 6 years by mailing a questionnaire to 1123 hospitals in Japan. The survey period was 2 years. We then collected clinical data on patients with prolonged febrile seizures (PFS) ≥40 min and those with AESD, and compared clinical data between the PFS and AESD groups.

RESULTS

The response rate for the primary survey was 42.3%, and 28.0% of hospitals which had applicable cases responded in the secondary survey. The incidence of AESD was 4.3% in patients with FSE ≥20 min and 7.1% in those with FSE ≥40 min. In the second survey, a total of 548 patients had FSE ≥40 min (AESD group, n = 93; PFS group, n = 455). Univariate analysis revealed significant between-group differences in pH, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, creatine kinase, NH₃, procalcitonin (PCT), uric acid, blood urea nitrogen, creatinine (Cr), and lactate. Multivariate analysis using stratified values showed that high PCT was an only risk factor for AESD. A prediction score of ≥3 was indicative of AESD, as determined using the following indexes: HCO3^- < 20 mmol/L (1 point), Cl <100 mEq/L (1 point), Cr ≥0.35 mg/dL (1 point), glucose ≥200 mg/dL (1 point), and PCT ≥1.7 pg/mL (2 points). The scoring system had sensitivity of 84.2% and specificity of 81.0%.

CONCLUSION

Incidence data and prediction scores for AESD will be useful for future intervention trials for AESD.

Neurodevelopmental Outcomes of High-Risk Preterm Infants: A Prospective Study in Japan

Objectives

To determine the neurodevelopmental outcomes of very-low-birth-weight infants (VLBWIs, birth weight <1,500 g) after 9 years of follow-up.

Methods

This study prospectively recruited 224 VLBWIs born from 2003 to 2009 in Kyushu University Hospital, Japan. Comorbidities of neurocognitive impairment, epilepsy, and autism spectrum disorder or attention-deficit hyperactivity disorder (ASD/ADHD) were assessed at age 3, 6, and 9 years.

Results

Neurodevelopmental profiles were obtained from 185 (83%), 150 (67%), and 119 (53%) participants at age 3, 6, and 9 years, respectively. At age 9 years, 25 (21%) VLBWIs showed intelligence quotient (IQ) <70, 11 (9%) developed epilepsy, and 14 (12%) had a diagnosis of ASD/ADHD. The prevalence of epilepsy was higher in children with an IQ <70 at age 9 years than in those with an IQ ≥70 (44% vs 0%). In contrast, ASD/ADHD appeared at similar frequencies in children with an IQ <70 (16%) and ≥70 (11%). Perinatal complications and severe brain lesions on MRI were considered common perinatal risks for developmental delay and epilepsy but not for ASD/ADHD. Male sex was identified as a unique risk factor for ASD/ADHD.

Conclusion

These data suggest that VLBWIs showed a higher prevalence of developmental delay, epilepsy, and ASD/ADHD at age 9 years than the general population. Distinct mechanisms might be involved in the pathogenic process of ASD/ADHD from those of developmental delay and epilepsy.

Clinical and electrophysiological features of acute flaccid myelitis: A national cohort study

OBJECTIVE

To summarize the neurophysiological properties of acute flaccid myelitis (AFM) and evaluate limb-based motor outcomes.

METHODS

Nerve conduction studies (NCS) in 49 patients (21 females, 28 males; median age = 52 m) with AFM (median = 7 d after onset; range 1-122 d) were reviewed. Neurophysiological findings, together with treatment and prognosis, and neurophysiology-neuroimaging correlations were analyzed.

RESULTS

The findings indicated that 64% of paralytic limbs during the acute stage (≤14 d after onset) showed diminished or absent compound muscle action potentials (CMAPs), 79% showed normal motor nerve conduction velocities, 55% showed decreased persistence or absent F-waves, and 95% showed normal sensory nerve conduction velocities. The rate of CMAP abnormalities increased from 41% on days 1-2 to 83% on days 13-14. The reduction in CMAP amplitude was correlated with weaker muscle strength at both the peak neurological deficit and the last follow-up. The baseline limb-based muscle strength at nadir and anterior horn-localized magnetic resonance imaging lesions at recovery stage (>14 d) were strong predictors of outcome at the last follow-up.

CONCLUSIONS

AFM typically shows neurophysiological features of neuronopathy.

SIGNIFICANCE

NCS is probably useful in the diagnosis and evaluation of AFM.

Favorable outcomes of interferon-α and ribavirin treatment for a male with subacute sclerosing panencephalitis

Subacute sclerosing panencephalitis (SSPE) is a slow virus infection associated with mutant measles virus (MeV). The long-term outcome of antiviral treatments remains to be determined. We herein present a Japanese boy who was diagnosed with SSPE at 10 years of age. Intraventricular infusions of interferon-α effectively prevented the progress of symptoms during 14 years of follow-up period. Flow-cytometric analysis demonstrated higher proportion of T helper 17 cells (Th17, 18.2%) than healthy controls (4.8-14.5%) despite the normal subpopulation of peripheral lymphocytes. These data suggest that a group of patients with SSPE may show favorable responses to intraventricular infusions of interferon-α.

Spatially varying correlation between environmental conditions and human leptospirosis in Sarawak, Malaysia

The spatial distribution of environmental conditions may influence the dynamics of vectorborne diseases like leptospirosis. This study aims to investigate the global and localised relationships between leptospirosis with selected environmental variables. The association between environmental variables and the spatial density of geocoded leptospirosis cases was determined using global Poisson regression (GPR) and geographically weighted Poisson regression (GWPR). A higher prevalence of leptospirosis was detected in areas with higher water vapour pressure (exp(â): 1.12; 95% CI: 1.02 - 1.25) and annual precipitation (exp(â): 1.15; 95% CI: 1.02 - 1.31), with lower precipitation in the driest month (exp(â): 0.85; 95% CI: 0.75 - 0.96) and the wettest quarter (exp(â): 0.88; 95% CI: 0.77 - 1.00). Water vapor pressure (WVP) varied the most in the hotspot regions with a standard deviation of 0.62 (LQ: 0.15; UQ; 0.99) while the least variation was observed in annual precipitation (ANNP) with a standard deviation of 0.14 (LQ: 0.11; UQ; 0.30). The reduction in AICc value from 519.73 to 443.49 indicates that the GWPR model is able to identify the spatially varying correlation between leptospirosis and selected environmental variables. The results of the localised relationships in this study could be used to formulate spatially targeted interventions. This would be particularly useful in localities with a strong environmental or socio-demographical determinants for the transmission of leptospirosis.

Brain-sparing cord blood transplantation for the borderline stage of adrenoleukodystrophy

Background

Adrenoleukodystrophy (ALD) is an X-linked disorder characterized by rapidly progressive deterioration of neurocognitive functions and premature death. In addition to the difficulty in identifying the earliest signs of ALD, treatment-associated exacerbation of neurological symptoms has been an obstacle to achieve successful hematopoietic cell transplantation (HCT) for affected children.

Case report

We report a 9-year-boy with ALD. He presented with impairment in social skills compatible to the diagnosis of autism spectrum disorder from 3 years of age. He showed progressive strabismus, slurred speech and dysmetria at 6 years of age. The head MRI showed symmetrical T2-hyperintense lesions in the occipital white matters with a gadolinium enhancement, which extended to the internal capsules. The Loes score was thus calculated as 13. Very-long-chain-fatty-acids were increased to 1.800 (C24:0/C22:0) and 0.077 (C26:0/C22:0) in leukocytes. Sanger sequencing confirmed the pathogenic variant in ABCD1 (NM_000033.4:p.Gly512Ser). After multidisciplinary discussions over the treatment options, we performed a cord blood HCT with a reduced intensity conditioning (fludarabine, melphalan and brain-sparing total body irradiation). He was fully recovered with >90% chimerism of donor leukocytes at 55 days after HCT. He experienced three times of generalized seizures after discharge, that has been well controlled for 2 years without other complications or neurocognitive deteriorations.

Conclusion

For patients with ALD on a borderline indication for HCT, brain-sparing irradiation might be an alternative option in reduced intensity conditioning. Careful decision-making process and tailored conditioning are critical for the successful outcome of HCT for children with ALD.

•

Therapeutic strategies remain to be established for adrenoleukodystrophy.

•

Multidisciplinary discussions are necessary for making a decision of treatment.

•

A 6-year-old boy achieved a successful engraftment after the transplantation.

•

The brain-sparing method might provide favorable outcomes for adrenoleukodystrophy.

A nation-wide survey of Japanese pediatric MOG antibody-associated diseases

OBJECTIVE

To elucidate the clinical characteristics of Japanese pediatric patients with acquired demyelinating diseases (ADS), positive for myelin oligodendrocyte glycoprotein antibody (MOG-IgG), we conducted a nation-wide survey.

METHODS

Information about pediatric patients under 18 years old with ADS was solicited with surveys sent to 323 facilities. In an initial survey, we asked whether the center had any patients with ADS, and the MOG-IgG serostatus of the patients. In a follow-up survey, we requested more precise information on patients with ADS.

RESULTS

Initial survey: 263 replies providing information on 175 patients were received. MOG-IgG were examined in 78 patients and 54 of those (69%) were positive for MOG-IgG. Follow-up survey: The characteristic involvement was optic neuritis, with visual disturbance and optic pain as characteristic symptoms. The relapse rate was 44% in patients positive for MOG-IgG, which was higher than that in seronegative patients (38%). For acute phase treatments, corticosteroid (CS), plasma exchange, and intravenous immunoglobulin (IVIG) were useful. To prevent relapse, CS, intermittent IVIG, immunosuppressants, and monoclonal antibodies were useful, but the efficacies of disease modifying drugs were uncertain. Sequelae such as visual disturbance, cognitive impairment, motor dysfunction, and epilepsy were observed in 11% of patients with MOG-IgG.

CONCLUSIONS

MOG antibody-associated diseases were found to be common among pediatric ADS patients. Since a variety of sequelae were observed in these patients, it is important to identify the appropriate treatment to ensure the best outcome. The presence of the MOG autoantibody should be taken into consideration as part of the diagnostic criteria for pediatric ADS.

Comprehensive genetic analysis confers high diagnostic yield in 16 Japanese patients with corpus callosum anomalies

Corpus callosum anomalies (CCA) is a common congenital brain anomaly with various etiologies. Although one of the most important etiologies is genetic factors, the genetic background of CCA is heterogenous and diverse types of variants are likely to be causative. In this study, we analyzed 16 Japanese patients with corpus callosum anomalies to delineate clinical features and the genetic background of CCAs. We observed the common phenotypes accompanied by CCAs: intellectual disability (100%), motor developmental delay (93.8%), seizures (60%), and facial dysmorphisms (50%). Brain magnetic resonance imaging showed colpocephaly (enlarged posterior horn of the lateral ventricles, 84.6%) and enlarged supracerebellar cistern (41.7%). Whole exome sequencing revealed genetic alterations in 9 of the 16 patients (56.3%), including 8 de novo alterations (2 copy number variants and variants in ARID1B, CDK8, HIVEP2, and TCF4) and a recessive variant of TBCK. De novo ARID1B variants were identified in three unrelated individuals, suggesting that ARID1B variants are major genetic causes of CCAs. A de novo TCF4 variant and somatic mosaic deletion at 18q21.31-qter encompassing TCF4 suggest an association of TCF4 abnormalities with CCAs. This study, which analyzes CCA patients usung whole exome sequencing, demonstrates that comprehensive genetic analysis would be useful for investigating various causal variants of CCAs.

Three-Year Longitudinal Motor Function and Disability Level of Acute Flaccid Myelitis

BACKGROUND

We summarize the long-term motor outcome and disability level in a cluster of pediatric patients with acute flaccid myelitis (AFM) associated with the enterovirus D68 outbreak in 2015.

METHODS

This is a nationwide follow-up questionnaire analysis study. Clinical data including the motor function (manual muscle strength test) and other neurological symptoms were collected at the acute (nadir), recovery (six months), and chronic (three years) stages. We use the Barthel index, which measures 10 variables describing activity of daily living and mobility to assess the disability level.

RESULTS

Clinical data of 33 patients with AFM (13 females, 20 males; median age = 4.1 years) were available. Among patients with tetraplegia or triplegia, paraplegia, and monoplegia at the acute stage, two of seven, four of thirteen, and two of thirteen exhibited complete recovery without paralysis; of those five of seven, eight of thirteen, and two of thirteen showed improvement with lesser limb involvement at the chronic stage, respectively. Nine patients (27%) demonstrated improvement at the recovery-to-chronic period. All six patients with positive isolation of enterovirus D68 from biological samples at the acute stage showed persistent motor deficits. Other neurological findings had better prognosis than motor weakness. Better Barthel index score at the chronic stage was observed (P < 0.001; median difference [95% confidence interval], 53 [40 to 63]), implying an improved disability level even in patients with persistent motor deficits.

CONCLUSIONS

AFM has a high rate of persistent motor deficits showing one- to two-limb paralysis. Disability level of patients with AFM, however, generally improved at the three-year time point.

Acute flaccid myelitis: cause, diagnosis, and management

Acute flaccid myelitis (AFM) is a disabling, polio-like illness mainly affecting children. Outbreaks of AFM have occurred across multiple global regions since 2012, and the disease appears to be caused by non-polio enterovirus infection, posing a major public health challenge. The clinical presentation of flaccid and often profound muscle weakness (which can invoke respiratory failure and other critical complications) can mimic several other acute neurological illnesses. There is no single sensitive and specific test for AFM, and the diagnosis relies on identification of several important clinical, neuroimaging, and cerebrospinal fluid characteristics. Following the acute phase of AFM, patients typically have substantial residual disability and unique long-term rehabilitation needs. In this Review we describe the epidemiology, clinical features, course, and outcomes of AFM to help to guide diagnosis, management, and rehabilitation. Future research directions include further studies evaluating host and pathogen factors, including investigations into genetic, viral, and immunological features of affected patients, host-virus interactions, and investigations of targeted therapeutic approaches to improve the long-term outcomes in this population.

Case Report: Acute Fulminant Cerebral Edema With Perivascular Abnormalities Related to Kawasaki Disease

Introduction: Kawasaki disease (KD) is an acute systemic vasculitis in children, but 0.4% of patients with KD exhibit central nervous system involvement. Acute encephalitis and encephalopathy accompanied with KD have been reported to be mostly self-limiting complications. Case Presentation: A 2-year-old girl developed recurrent vomiting, a cluster of generalized seizures, and decreased consciousness on day 12 after the onset of KD. Magnetic resonance imaging (MRI) T2-weighted images on day 13 showed high signal intensities in bilaterally symmetrical and subcortical white matter and thalamus, and linear radial hyperintensities parallel to the cerebral vessels of the periventricular white matter. Diffuse white matter hyperintensity on the apparent diffusion coefficient map suggested vasogenic edema. Subsequently, lethal cerebral edema rapidly progressed in 8 hrs after the MRI examination. Conclusion: To our knowledge, acute fulminant cerebral edema in patients with KD has not been previously reported. We should be aware of the possibility of severe encephalitis related to KD. Furthermore, diffuse white matter vasogenic edema with perivascular abnormalities on MRI may be an alerm, potentially leading to fatal cerebral edema.

Effect of a vaccine information statement (VIS) on immunization status and parental knowledge, attitudes, and beliefs regarding infant immunization in Japan

BACKGROUND

Because of the overabundance of vaccination information on the internet, in the media, and on social media, providing clear and correct information on immunization is critical for parental decision-making. In 2018, the Japan Pediatric Society created and distributed a Vaccine Information Statement (VIS) to provide appropriate immunization information to caregivers. The objectives of the present study were to evaluate the effect of the VIS on immunization rates, adherence to schedule, and parental understanding of immunization in Japan.

METHODS

This cross-sectional study was conducted at 18 centers in 2 prefectures in Japan. Caregivers were assigned to an intervention group, which received the VIS and a questionnaire when their child reached the age of 1 month, and a control group, which received only the questionnaire. Using the self-reported questionnaires, we evaluated vaccination rates and schedule adherence at age 2 months, and parental knowledge, attitudes, and beliefs regarding immunization. Three months later, the questionnaires were returned, and the findings were compared between the 2 groups.

RESULTS

We contacted 422 and 428 persons in the intervention and control groups, respectively, and 111/422 (26.3%) and 119/428 (27.8%) returned the surveys. Vaccination rates and adherence rates for the first dose of 4 recommended vaccines did not differ significantly (P > 0.25); however, there were some positive effects on items related to vaccine knowledge (P = 0.03), perceived benefits (P = 0.02), perceived barriers (P < 0.001), and perceived behavioral control (P = 0.01).

CONCLUSION

The VIS improved parent comprehension of infant immunization. Future studies should examine if the effects of such an intervention persist and affect vaccine uptake throughout childhood.

Clinical and genetic characteristics of patients with Doose syndrome

OBJECTIVE

To elucidate the genetic background and genotype-phenotype correlations for epilepsy with myoclonic-atonic seizures, also known as myoclonic-astatic epilepsy (MAE) or Doose syndrome.

METHODS

We collected clinical information and blood samples from 29 patients with MAE. We performed whole-exome sequencing for all except one MAE case in whom custom capture sequencing identified a variant.

RESULTS

We newly identified four variants: SLC6A1 and HNRNPU missense variants and microdeletions at 2q24.2 involving SCN1A and Xp22.31 involving STS. Febrile seizures preceded epileptic or afebrile seizures in four patients, of which two patients had gene variants. Myoclonic-atonic seizures occurred at onset in four patients, of which two had variants, and during the course of disease in three patients. Variants were more commonly identified in patients with a developmental delay or intellectual disability (DD/ID), but genetic status was not associated with the severity of DD/ID. Attention-deficit/hyperactivity disorder and autistic spectrum disorder were less frequently observed in patients with variants than in those with unknown etiology.

SIGNIFICANCE

MAE patients had genetic heterogeneity, and HNRNPU and STS emerged as possible candidate causative genes. Febrile seizures prior to epileptic seizures and myoclonic-atonic seizure at onset indicate a genetic predisposition to MAE. Comorbid conditions were not related to genetic predisposition to MAE.

Acute Flaccid Myelitis With Neuroradiological Finding of Brachial Plexus Swelling

BACKGROUND

Acute flaccid myelitis is a recently defined clinically distinct syndrome of polio-like acute flaccid paralysis. Acute flaccid myelitis cases show characteristic neuroradiological features of longitudinal spinal cord lesions with predominant gray matter involvement. Current evidence suggests injury to the anterior horn neurons as the underlying mechanism.

METHODS

We describe three patients with acute flaccid myelitis who developed flaccid upper limb weakness with diminished deep tendon reflexes after prodromal fever. Spinal magnetic resonance imaging (MRI) (axial and sagittal T1- and T2-weighted sequences) and brachial plexus MRI (coronal short tau inversion recovery sequence) at the acute stage were performed.

RESULTS

Spinal MRI showed extensive longitudinal lesion in the spinal cord with predominant gray matter involvement. We were able to demonstrate concurrent swelling and hyperintensity in the brachial plexus in all the three patients at the acute stage.

CONCLUSION

The coexisting signal intensities suggest an extension of acute flaccid myelitis pathology to the brachial plexus, highlighting the possible peripheral nerve involvement in acute flaccid myelitis.

Disseminated cortical and subcortical lesions in neonatal enterovirus 71 encephalitis

Enteroviruses are one of the most important causes of viral encephalitis in the neonatal period. However, the non-specificity of the symptoms presented renders its diagnosis challenging. Intracranial MRI has been reported to be a very useful imaging modality that can detect the characteristic white matter lesions around the periventricular regions. In this study, we report a case of a patient with neonatal encephalitis who presented with normal white blood cell counts in the initial cerebrospinal fluid analysis. A lumbar puncture retap identified pleocytosis, and polymerase chain reaction assays detected enterovirus 71 in the blood and stool samples. Furthermore, MRI revealed atypical disseminated cortical and subcortical white matter lesions on diffusion weighted images, and neuroradiological re-evaluation showed necrotic changes 2 weeks later. This unique case expands our knowledge of the spectrum of neurological disorders due to enterovirus 71 infection in neonatal period.

Isolated cranial neuritis of the oculomotor nerve: Expanding the MOG phenotype?

Autoantibody against myelin oligodendrocyte glycoprotein (MOG) has been reported in a range of demyelinating neurological entities. Recent studies demonstrate a wider spectrum of MOG-IgG-associated disorders with the discovery of MOG-IgG-positive brainstem encephalitis, cortical encephalitis, and cranial nerve involvement with concurrent central nervous system involvement. We present a MOG-IgG-positive pediatric patient diagnosed with isolated oculomotor neuritis without concurrent central nervous system neuroimaging lesions, in the absence of a demyelinating event. Brain MRI shows swelling and gadolinium enhancement of the left oculomotor nerve at the cisternal segment. This is the first report to demonstrate MOG-IgG seropositivity in isolated cranial nerve lesions. This case may expand the clinical phenotype of MOG-IgG-associated diseases, and clinicians should not hesitate to test for MOG-IgG in cases with neuroimaging features of cranial neuritis alone.

The recurrent postzygotic pathogenic variant p.Glu47Lys in RHOA causes a novel recognizable neuroectodermal phenotype

RHOA is a member of the Rho family of GTPases that are involved in fundamental cellular processes including cell adhesion, migration, and proliferation. RHOA can stimulate the formation of stress fibers and focal adhesions and is a key regulator of actomyosin dynamics in various tissues. In a Genematcher-facilitated collaboration, we were able to identify four unrelated individuals with a specific phenotype characterized by hypopigmented areas of the skin, dental anomalies, body asymmetry, and limb length discrepancy due to hemihypotrophy of one half of the body, as well as brain magnetic resonance imaging (MRI) anomalies. Using whole-exome and ultra-deep amplicon sequencing and comparing genomic data of affected and unaffected areas of the skin, we discovered that all four individuals carried the identical RHOA missense variant, c.139G>A; p.Glu47Lys, in a postzygotic state. Molecular modeling and in silico analysis of the affected p.Glu47Lys residue in RHOA indicated that this exchange is predicted to specifically alter the interaction of RHOA with its downstream effectors containing a PKN-type binding domain and thereby disrupts its ability to activate signaling. Our findings indicate that the recurrent postzygotic RHOA missense variant p.Glu47Lys causes a specific mosaic disorder in humans.

De novo p.G696S mutation in COL4A1 causes intracranial calcification and late-onset cerebral hemorrhage: A case report and review of the literature

BACKGROUND

The collagen type IV alpha 1 chain (COL4A1) is an essential component of the basement membrane in small vessels. Pathogenic variants in COL4A1 cause perinatal cerebral hemorrhages in an autosomal-dominant fashion. However, little is known about the long-term outcomes of patients with mildly affecting COL4A1 mutations.

CASE REPORT

We report a 17-year-old boy, who presented with recurrent intracranial hemorrhages in the periventricular white matter. He had been followed-up as a child with cerebral palsy bearing intracranial calcifications, developmental delay and epilepsy. Screening tests in infancy provided negative results for intrauterine infections. Severe motor and cognitive deficits persisted after admission. Carbazochrome was introduced on day 19 of admission, which appeared to prevent extension and reactivation of cerebral hemorrhages for over 6 months after discharge.

RESULTS

Targeted sequencing of NOTCH3 and TREX1 excluded causal mutations in these genes. The whole-exome sequencing revealed that he carried a de novo mutation in COL4A1 (p.Gly696Ser). An overview of the literature for 345 cases with COL4A1 mutations supported evidence that p.Gly696Ser is associated with the unique phenotype of late-onset hemorrhage among patients with COL4A1-associated cerebral angiopathy.

CONCLUSIONS

This case first demonstrates that infants with COL4A1-associated leukoencephalopathy and calcifications have a risk for developing the rupture of small vessels in the cerebral white matter after 10 years of age.

Genomic backgrounds of Japanese patients with undiagnosed neurodevelopmental disorders

BACKGROUND

Recently, many genes related to neurodevelopmental disorders have been identified by high-throughput genomic analysis; however, a comprehensive understanding of the mechanism underlying neurodevelopmental disorders remains to be established. To further understand these underlying mechanisms, we performed a comprehensive genomic analysis of patients with undiagnosed neurodevelopmental disorders.

METHODS

Genomic analysis using next-generation sequencing with a targeted panel was performed for a total of 133 Japanese patients (male/female, 81/52) with previously undiagnosed neurodevelopmental disorders, including developmental delay (DD), intellectual disability (ID), autism spectrum disorder (ASD), and epilepsy. Genomic copy numbers were also analyzed using the eXome Hidden Markov Model (XHMM).

RESULTS

Thirty-nine patients (29.3%) exhibited pathogenic or likely pathogenic findings with single-gene variants or chromosomal aberrations. Among them, 20 patients were presented here. Pathogenic or likely pathogenic variants were identified in 18 genes, including ACTG1, CACNA1A, CHD2, CDKL5, DNMT3A, EHMT1, GABRB3, GABRG2, GRIN2B, KCNQ3, KDM5C, MED13L, SCN2A, SHANK3, SMARCA2, STXBP1, SYNGAP1, and TBL1XR1.

CONCLUSION

A diagnostic yield of 29.3% in this study was nearly the same as that previously reported from other countries. Thus, we suggest that there is no difference in genomic backgrounds in Japanese patients with undiagnosed neurodevelopmental disabilities. Although most of the patients possessed de novo variants, one of the patients showed an X-linked inheritance pattern. As X-linked recessive disorders exhibit the possibility of recurrent occurrence in the family, comprehensive molecular diagnosis is important for genetic counseling.

Decision-making dilemmas of paediatricians: a qualitative study in Japan

OBJECTIVE

To delineate the critical decision-making processes that paediatricians apply when treating children with life-threatening conditions and the psychosocial experience of paediatricians involved in such care.

DESIGN

We conducted semistructured, individual face-to-face interviews for each participant from 2014 to 2015. The content of each interview was subjected to a comprehensive qualitative analysis. The categories of dilemma were extracted from a second-round content analysis.

PARTICIPANTS

Participants were board-certified paediatricians with sufficient experience in making decisions in relation to children with severe illnesses or disabilities. We repeated purposive sampling and analyses until we reached saturation of the category data.

RESULTS

We performed interviews with 15 paediatricians. They each reported both unique and overlapping categories of dilemmas that they encountered when making critical decisions. The dilemmas included five types of causal elements: (1) paediatricians' convictions; (2) the quest for the best interests of patients; (3) the quest for medically appropriate plans; (4) confronting parents and families and (5) socioenvironmental issues. Dilemmas occurred and developed as conflicting interactions among these five elements. We further categorised these five elements into three principal domains: the decision-maker (decider); consensus making among families, colleagues and society (process) and the consequential output of the decision (consequence).

CONCLUSIONS

This is the first qualitative study to demonstrate the framework of paediatricians' decision-making processes and the complex structures of dilemmas they face. Our data indicate the necessity of establishing and implementing an effective support system for paediatricians, such as structured professional education and arguments for creating social consensus that assist them to reach the best plan for the management of severely ill children.

Long surviving classical Menkes disease treated with weekly intravenous copper therapy

Menkes diseases (MD) is an X-linked recessive neurodegenerative disorder of copper metabolism, characterized by progressive multisystemic involvement. Death in the early childhood is usually observed in classical patients. Although a definite cure has not been established, copper replacement therapy administered parenterally may modify the severity of MD and permitted survival into adolescence. Subcutaneous copper-histidine supplementation is the current choice of therapy, and long-term administration is not desirable because of the expected nephrotoxicity. We report here the case of a 29-year-old male with MD who tolerated long-term intravenous copper therapy initiated at 2 months. Molecular analysis revealed hemizygous deletion mutation of ATP7A previously reported in classical MD. Although neurodevelopement is poor, no major event of central nervous system is observed, and he enjoys a good social life by interacting using gestures. Optimum management is unknown, and closed follow-up is mandatory for clarification of this phenotype.

Comprehensive analysis of coding variants highlights genetic complexity in developmental and epileptic encephalopathy

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.

Many causative genes are known for epileptic or developmental and epileptic encephalopathies (EE/DEE) yet a genetic diagnosis cannot be made for many patients. Here, the authors analyse whole exome sequencing data from a Japanese case−control cohort to identify common, rare and ultra-rare coding variants associated with EE/DEE.

Serial MRI findings of acute flaccid myelitis during an outbreak of enterovirus D68 infection in Japan

OBJECIVE

To clarify the neuroimaging findings of children with acute flaccid myelitis during an outbreak of EV-D68 infection.

METHODS

We performed a detailed review of the spinal and cranial MRI results of 54 children with acute flaccid myelitis. We focused on the range of longitudinal lesions, the localization and appearance of lesions within a horizontal section, Gadolinium-enhancement, and changes over time.

RESULTS

All children had longitudinal spinal lesions involving central gray matter. Twenty-six children had lesions spanning the entire spine. Six of them had weakness in all limbs, whereas seven had weakness of only one limb. Thirty-eight children had lesions in both gray and white matter and limb weakness tended to be more severe in these children. During the acute period, spinal lesions showed bilateral ill-defined widespread T2 hyperintensity. During the subacute period, lesions were well defined and confined to the anterior horn. The distribution of limb weakness was correlated with the appearance of lesions during the subacute period. Gadolinium enhancement was performed in 37 children, and enhancement was seen in the cauda equina in 29 children. Enhancement was infrequent within 2 days after onset but was seen in almost all children thereafter. Twenty-two children had brainstem lesions continuous with spinal lesions.

CONCLUSION

Extensive longitudinal spinal lesions were characteristic in children with acute flaccid myelitis. Lesions were usually bilateral and widespread during the acute period, whereas localization to the anterior horn could become obvious. Although enhancement of the cauda equina was often observed, its appearance was sometimes delayed.

An acute encephalopathy with reduced diffusion in BRAF-associated cardio-facio-cutaneous syndrome

BACKGROUND

Cardio-facio-cutaneous syndrome (CFCS) is a rare genetic disorder characterized by cardiovascular anomalies, dysmorphic faces, ectodermal abnormalities and developmental delays. Mutations in BRAF and other RAS-MAPK pathway-associated genes are commonly identified in patients with CFCS. While this molecular pathway is known to be associated with neuro-inflammatory conditions, only one case with CFCS has been reported thus far to develop acute encephalopathy in childhood.

CASE REPORT

A 3-year-old boy with dysmorphic features and mild psychomotor delay developed acute encephalopathy. After a 45-min long, generalized seizure, the magnetic resonance imaging revealed that the restricted diffusion signals spread to the bilateral subcortical white matters on day 1 of illness. Despite the 14 days of intensive care, the acute symptoms of encephalopathy left him intractable epilepsy and severe neurocognitive impairments. The whole-exome sequencing analysis identified a de novo heterozygous mutation of BRAF (NM_004333:p.Thr241Met) in this case.

CONCLUSION

The present case suggests that the hyperactive condition of ERK signals might augment the development of acute encephalopathy and post-encephalopathic epilepsy in childhood.

Surgical histopathology of limited dorsal myeloschisis with flat skin lesion

PURPOSE

Limited dorsal myeloschisis (LDM) is characterized by two invariable features: a focal closed neural tube defect and a fibroneural stalk linking the skin lesion to the underlying spinal cord. Although detailed histopathological findings of the LDM stalk were originally described by Pang et al., the precise relationship between the histopathological findings and clinical manifestations including intraoperative findings has not been fully determined.

METHODS

We retrospectively analyzed the histopathological findings of the almost entire stalk and their relevance to the clinical manifestations in six Japanese LDM patients with flat skin lesions.

RESULTS

Glial fibrillary acidic protein (GFAP)-immunopositive neuroglial tissues were observed in three of the six patients. Unlike neuroglial tissues, peripheral nerve fibers were observed in every stalk. In four patients, dermal melanocytosis, "Mongolian spot," was seen surrounding the cigarette-burn lesion. In three of these four patients, numerous melanocytes were distributed linearly along the long axis of the LDM stalk, which might represent migration of melanocytes from trunk neural crest cells during formation of the LDM stalk.

CONCLUSION

Immunopositivity for GFAP in the LDM stalk was observed in as few as 50% of our patients, despite the relatively extensive histopathological examination. We confirm that the clinical diagnosis of LDM should be made based on comprehensive histopathological examination as well as clinical manifestations. The profuse network of peripheral nerve fibers in every stalk and the high incidence of melanocyte accumulation associated with dermal melanocytosis might assist the histopathological diagnosis of LDM.

West Syndrome in an Infant With Vitamin B12 Deficiency Born to Autoantibodies Positive Mother

Infantile vitamin B12 deficiency, a rare nutritional disorder in developed countries, is characterized by megaloblastic anemia and non-specific symptoms, including failure to thrive, hypotonia, and seizure. Symptoms usually develop at 6 months of age. Exclusively breast-fed infants of vegan-diet mothers are particularly at risk. We report the case of a 7-month-old boy with West syndrome born to a mother with subclinical vitamin B12 deficiency due to autoantibodies. Electroencephalography revealed the characteristic hypsarrhythmia pattern, whereas cranial magnetic resonance imaging revealed cerebral atrophy and hypomyelination. Biochemical analysis revealed elevated urinary methylmalonic acid and homocysteine and reduced plasma methionine. Serum vitamin B12 levels were extremely low in both the child and his mother. The mother tested positive for both anti-intrinsic factor and anti-parietal cell antibodies. Low-dose adrenocorticotropic hormone was effective for seizure control. Contrary to previous reports, age-appropriate neurodevelopment was not achieved despite rapid normalization of metabolic profile with vitamin B12 supplementation. Further investigations failed to detect any causative mutations in the genes associated with developmental and epileptic encephalopathy as well as metabolic and other identifiable disorders known to cause West syndrome. To the best of our knowledge, this is the first reported case in which maternal anti-intrinsic factor antibody was considered to be the reason for infantile vitamin B12 deficiency with West syndrome. Differential diagnosis of West syndrome should include vitamin B12 deficiency due to its treatable nature, and early diagnosis is essential to prevent permanent neurological consequences.

Mulberries in the urine: a tell-tale sign of Fabry disease

Fabry disease is a treatable progressive illness of inborn error causing eventual multiple organ dysfunction in advanced untreated cases. We report on a classic Fabry child patient presenting with urinary mulberry cells and bodies without renal involvement. This report emphasizes the usefulness of urinary microscopic findings in the early diagnosis of Fabry disease.

Deletions of SCN2A and SCN3A genes in a patient with West syndrome and autistic spectrum disorder

SCN2A encodes the alpha-subunit of voltage-gated sodium channel, Nav1.2, which is highly expressed at an early stage of the postnatal brain. Genetic studies revealed that de novo heterozygous mutations of SCN2A caused severe developmental disorders in childhood, such as autism and epileptic encephalopathy. However, few reports have demonstrated the cases carrying segmental deletions at the SCN2A locus for those with epileptic disorders. In this study, we report a 1.8-year-old boy, who presented with West syndrome in infancy and developed the sequelae of psychomotor delay and autism. Since whole-exome sequencing did not detect pathogenic mutations, we extensively searched for microdeletions and duplications by applying the eXome Hidden Markov Model (XHMM) for read depths of sequenced intervals. Using this approach, we identified a de novo deletion spanning the 1.1-Mb region of chromosome 2q24.3. We found that the deleted interval included the SCN2A and SCN3A loci. These data validate the utility of XHMM and support that SCN2A is involved in the pathogenic processes underlying epileptic encephalopathy in childhood.

Clinical Features of Acute Flaccid Myelitis Temporally Associated With an Enterovirus D68 Outbreak: Results of a Nationwide Survey of Acute Flaccid Paralysis in Japan, August-December 2015

Background

Acute flaccid myelitis (AFM) is an acute flaccid paralysis syndrome with spinal motor neuron involvement of unknown etiology. We investigated the characteristics and prognostic factors of AFM clusters coincident with an enterovirus D68 (EV-D68) outbreak in Japan during autumn 2015.

Methods

An AFM case series study was conducted following a nationwide survey from August to December 2015. Radiographic and neurophysiologic data were subjected to centralized review, and virology studies were conducted for available specimens.

Results

Fifty-nine AFM cases (58 definite, 1 probable) were identified, including 55 children and 4 adults (median age, 4.4 years). The AFM epidemic curve showed strong temporal correlation with EV-D68 detection from pathogen surveillance, but not with other pathogens. EV-D68 was detected in 9 patients: 5 in nasopharyngeal, 2 in stool, 1 in cerebrospinal fluid (adult case), and 1 in tracheal aspiration, nasopharyngeal, and serum samples (a pediatric case with preceding steroid usage). Cases exhibited heterogeneous paralysis patterns from 1- to 4-limb involvement, but all definite cases had longitudinal spinal gray matter lesions on magnetic resonance imaging (median, 20 spinal segments). Cerebrospinal fluid pleocytosis was observed in 50 of 59 cases (85%), and 8 of 29 (28%) were positive for antiganglioside antibodies, as frequently observed in Guillain-Barré syndrome. Fifty-two patients showed variable residual weakness at follow-up. Good prognostic factors included a pretreatment manual muscle strength test unit score >3, normal F-wave persistence, and EV-D68-negative status.

Conclusions

EV-D68 may be one of the causative agents for AFM, while host susceptibility factors such as immune response could contribute to AFM development.

[Acute Flaccid Myelitis]

Acute flaccid myelitis (AFM) is a newly defined, rare, but clinically distinct syndrome of acute flaccid paralysis with spinal motor neuron involvement of unknown etiology. Clusters of AFM coincided with a nationwide outbreak of enterovirus D68 (EV-D68) in the United States during autumn to winter of 2014 and in Japan during the autumn of 2015. Although EV-D68 was detected in only 20% of the AFM patients, mainly from respiratory specimens without apparent viral detection from blood and cerebrospinal fluid (CSF) samples, strong temporal associations were noted. Core symptoms of AFM are focal limb weakness and cranial nerve dysfunction with acute onset, although limb paralysis varied in type and severity. Most patients showed extensive longitudinal spinal involvement on magnetic resonance imaging, pleocytosis in CSF, and abnormal motor conduction and/or F-waves in neurophysiological investigations in the acute phase which was within two weeks after onset. Immunomodulation therapy consisting of high-dose intravenous immunoglobulin or pulse methylprednisolone did not improve prognosis. Only about 10% of the patients showed complete recovery of limb weakness, but others had variable residual weakness at follow-up. With no effective treatment identified in the acute stage, studies are required to elucidate the pathophysiology and pathomechanisms of AFM and to develop both preventive measures and novel therapeutic interventions.

Mutations in NSD1 and NFIX in Three Patients with Clinical Features of Sotos Syndrome and Malan Syndrome

Mutations in nuclear receptor SET domain-containing protein 1 gene ( NSD1 ) are related to Sotos syndrome, which is characterized by overgrowth, macrocephaly, distinctive features, and neurodevelopmental disabilities. On the other hand, mutations in the nuclear factor I/X gene ( NFIX ) can lead to Malan syndrome, also known as Sotos-like syndrome, or to the Marshall-Smith syndrome. In this study, using next generation sequencing (NGS), we identified de novo mutations in NSD1 and NFIX in three patients with developmental disabilities associated with overgrowth or macrocephaly. Overall, we confirmed that clinical entities of congenital malformation syndromes can be expanded by molecular diagnoses via NGS.

[Successful treatment with topiramate in a case of idiopathic intracranial hypertension refractory to acetazolamide]

A 6-year-old girl experienced nausea and vomiting for 3 weeks and double vision for 1 week prior to her first visit to our hospital. She had bilateral ophthalmoplegia from sixth cranial nerve palsy and papilledema. Her brain MRI showed normal brain parenchyma. The lumbar cerebrospinal fluid (CSF) opening pressure was 1000 mm of water measured with normal CSF contents. From these findings, she was diagnosed with idiopathic intracranial hypertension (IIH). Initial lumbar puncture (LP) immediately improved her symptoms, but acetazolamide, a first line drug for the treatment of IIH, failed to maintain the remission, and three more periodical LP were required to relieve her symptoms every 2 weeks. After the fourth LP, acetazolamide was switched to a second line drug for IIH, topiramate, which was found to be highly effective in controlling IIH in a short time period. The long process of IIH causes vision loss, therefore, its prompt treatment is vital. In cases refractory to medical treatment, surgical treatments such as CSF shunt are considered. Acetazolamide is used in most IIH cases after the initial diagnosis, but in this case, it was ineffective, and topiramate was highly effective. Both acetazolamide and topiramate are inhibitors of carbonic anhydrase isoforms involved in CSF secretion. Inhibition of choroid plexus carbonic anhydrase by these drugs leads to decreased CSF secretion and the consequent control of intracranial pressure. Higher isoform specificity and increased lipophilic nature of topiramate, which are advantageous for passing through the blood brain barrier, may be the reasons for better activity than acetazolamide, at least in the present case. Topiramate might be effective and should be considered for refractory IIH cases before surgical treatments.

Venous anomaly analogous to vertical embryonic positioning of the straight sinus associated with atretic cephalocele at the suboccipital region

BACKGROUND

The coexistence of venous anomalies, such as vertical embryonic positioning of the straight sinus (VEP of SS), has been reported in patients with atretic cephalocele (AC). VEP of SS has been exclusively encountered when the AC is found above the torcular.

CLINICAL PRESENTATION

We report a patient with suboccipital AC associated with venous anomalies analogous to VEP of SS, consisted of the Galenic venous system which did not drain into the straight sinus in the tentorium, but into the falcine sinus instead. Differences with VEP of SS in our case had no anatomical relationship between the falcine sinus and the suboccipital AC and no large cerebrospinal fluid space around the falcine sinus. A detailed neuroradiological examination was helpful for detecting these minute anomalies.