Publications by authors named "Tomoyuki Akiyama"

Article Synopsis
  • The 2015 updated definition of status epilepticus (SE) emphasizes the importance of early treatment, identifying key time points for diagnosis and management.
  • Japan has revised its pediatric SE treatment guidelines, recommending buccal midazolam for pre-hospital and in-hospital treatment when intravenous access is not possible, while benzodiazepines are preferred when intravenous access is available.
  • The updated guidelines note similarities in seizure cessation rates across different medications, highlight the need for further recommendations on nonconvulsive status epilepticus (NCSE), and plan to explore the effects of NCSE treatment on children's outcomes in future editions.
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Introduction: Post-operative complications of corpus callosotomy (CC) in children, prolonged hospitalization due to inactivity as acute disconnection syndrome is occasionally experienced. We aimed to clarify this issue and its risk factors with a hypothesis that electroencephalogram (EEG) findings as measures of functional lateralization may be among prognostic factors for post-operative recovery.

Materials And Methods: Twenty-three patients with childhood-onset drug-resistant epilepsy who underwent total CC between April 2017 and December 2023 were included in the study and they were divided into two groups based on the duration of post-operative hospitalization as an indicator of recovery of daily living activity.

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Pediatric ALK-positive anaplastic large cell lymphoma is a rare subtype of non-Hodgkin lymphoma, and approximately 30% of patients relapse following treatment with conventional chemotherapy. Alectinib monotherapy has demonstrated excellent activity in relapsed and refractory ALCL, but its role as a maintenance therapy after hematopoietic cell transplantation is unclear. We experienced a relapse case of pediatric ALK-positive ALCL with central nervous system involvement treated with alectinib maintenance therapy following cord blood transplantation.

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Purpose: In developmental and epileptic encephalopathy with spike-and-wave activation in sleep (DEE-SWAS), the thalamocortical network is suggested to play an important role in the pathophysiology of the progression from focal epilepsy to DEE-SWAS. Ethosuximide (ESM) exerts effects by blocking T-type calcium channels in thalamic neurons. With the thalamocortical network in mind, we studied the prediction of ESM effectiveness in DEE-SWAS treatment using phase-amplitude coupling (PAC) analysis.

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Objectives: Hypophosphatasia (HPP) is a rare skeletal dysplasia caused by variants in the () gene. More than 400 pathogenic variants of the gene have been registered in the ALPL gene variant database. Here, we describe the case of a Japanese child with odonto-hypophsphatasia (odonto-HPP) and a novel variant.

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Objective: The discovery of objective indicators for recent epileptic seizures will help confirm the diagnosis of epilepsy and evaluate therapeutic effects. Past studies had shortcomings such as the inclusion of patients under treatment and those with various etiologies that could confound the analysis results significantly. We aimed to minimize such confounding effects and to explore the small molecule biomarkers associated with the recent occurrence of epileptic seizures using urine metabolomics.

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West syndrome, an infantile developmental and epileptic encephalopathy with a deleterious impact on long-term development, requires early treatment to minimize developmental abnormality; in such cases, epilepsy surgery should be considered a powerful therapeutic option. We describe a 10-month-old female admitted with West syndrome associated with a hemispheric lesion following abusive head trauma. Her seizures were suppressed by hemispherotomy at 12 months of age, leading to developmental improvement.

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Background: MECP2 is a well-known causative gene for Rett syndrome but other phenotypes have also been reported. Here, we report a case of a female patient with adolescent-onset progressive myoclonus epilepsy (PME) carrying a novel truncating mutation in the MECP2 gene.

Case Report: The patient was a 29-year-old woman with infantile-onset intellectual disability of unspecified cause.

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Background: Children with a congenital heart disease (CHD) are at a higher risk of developing epilepsy than the general population, but detailed characteristics of CHD-associated epilepsy have not been clarified. The purposes of this study were to determine the risk factors for developing epilepsy associated with CHD and to elucidate the characteristics of such epilepsy.

Methods: We performed a retrospective cohort study based on medical records of pediatric patients with CHD who were born between January 2006 and December 2016, underwent cardiac surgery at Okayama University Hospital, and were followed up until at least age three years.

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Objective: The ketogenic diet (KD), a high-fat and low-carbohydrate diet, is effective for a subset of patients with drug-resistant epilepsy, although the mechanisms of the KD have not been fully elucidated. The aims of this observational study were to investigate comprehensive short-term metabolic changes induced by the KD and to explore candidate metabolites or pathways for potential new therapeutic targets.

Methods: Subjects included patients with intractable epilepsy who had undergone the KD therapy (the medium-chain triglyceride [MCT] KD or the modified Atkins diet using MCT oil).

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We developed an artificial intelligence (AI) technique to identify epileptic discharges (spikes) in pediatric scalp electroencephalograms (EEGs). We built a convolutional neural network (CNN) model to automatically classify steep potential images into spikes and background activity. For the CNN model' training and validation, we examined 100 children with spikes in EEGs and another 100 without spikes.

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Objective: The use of folic acid (FA) has been discouraged in cerebral folate deficiency (CFD) because, theoretically, it could inhibit the transport of 5-methyltetrahydrofolic acid (5MTHF) across the blood-cerebrospinal fluid (CSF) barrier. We present the clinical biochemical data of two cases with CFD to support this hypothesis.

Methods: We measured CSF and serum 5MTHF concentrations in a patient with Kearns-Sayre syndrome (KSS) and a patient homozygous for C677T polymorphism before and during folate supplementation therapy.

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Early-onset isolated (DYT1) dystonia is one of the most common forms of primary dystonia in childhood, and deep brain stimulation of the globus pallidus internus (GPi-DBS) is a highly effective treatment for it. However, the effectiveness of GPi-DBS in monozygotic twins with DYT1 dystonia has never been reported globally. Here, we report the cases of monozygotic twins with DYT1 dystonia who were treated using GPi-DBS, and we include a literature review.

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Objectives: Sepiapterin reductase deficiency (SRD) causes central nervous system symptoms due to dopamine and serotonin depletion because sepiapterin reductase plays an important role in tetrahydrobiopterin biosynthesis. SRD cannot be detected by newborn screening because of the absent hyperphenylalaninemia. To diagnose SRD biochemically, confirmation of reduced monoamine metabolites and elevated sepiapterin in the cerebrospinal fluid (CSF) has been considered necessary, because a past study showed no elevation of urine sepiapterin.

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Background: Hypophosphatasia (HPP) is a rare inherited metabolic disorder caused by mutations in the ALPL gene, which encodes tissue nonspecific alkaline phosphatase. The severity of HPP is widely diverse from the perinatal form to the adult mild form. The former represents the most severe form and was earlier associated with high mortality due to pneumonia which was caused by severe hypomineralization of the bones-such as chest deformity and fractured ribs-and muscle weakness.

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Objective: To determine whether sirolimus, a mechanistic target of rapamycin (mTOR) inhibitor, reduces epileptic seizures associated with focal cortical dysplasia (FCD) type II.

Methods: Sixteen patients (aged 6-57 years) with FCD type II received sirolimus at an initial dose of 1 or 2 mg/day based on body weight (FCDS-01). In 15 patients, the dose was adjusted to achieve target trough ranges of 5-15 ng/mL, followed by a 12-week maintenance therapy period.

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Fast oscillations (FOs) >40 Hz in electroencephalograms (EEGs) are associated with ictogenesis and epileptogenesis in adults and children with epilepsy. However, only a few previous studies showed FOs in neonates. Reported frequencies of such neonatal FOs were in the low-gamma (<60 Hz) band and, therefore, they were not high compared to those in pediatric patients.

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Aim: Ripple-band epileptic high-frequency oscillations (HFOs) can be recorded by scalp electroencephalography (EEG), and tend to be associated with epileptic spikes. However, there is a concern that the filtration of steep waveforms such as spikes may cause spurious oscillations or "false ripples." We excluded such possibility from at least some ripples by EEG differentiation, which, in theory, enhances high-frequency signals and does not generate spurious oscillations or ringing.

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Epileptic seizures are core symptoms in focal cortical dysplasia (FCD), a disease that often develops in infancy. Such seizures are refractory to conventional antiepileptic drugs (AED) and temporarily disappear in response to AED in only 17% of patients. Currently, surgical resection is an important option for the treatment of epileptic seizures in FCD.

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Objective: Physiological gamma and ripple activities may be linked to neurocognitive functions. This study investigated the relationship between development and non-epileptic, probably physiological, fast (40-200 Hz) oscillations (FOs) including gamma (40 - 80 Hz) and ripple (80 - 200 Hz) oscillations in scalp EEG in children with neurodevelopmental disorders.

Methods: Participants were 124 children with autism spectrum disorder (ASD) and/or attention deficit/hyperactivity disorder (ADHD).

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Background: DYT-TOR1A is caused by a GAG deletion in the TOR1A gene. While it usually manifests as early-onset dystonia, its phenotype is extremely diverse, even within one family. Recent reports have revealed that some DYT-TOR1A cases have novel mutations in the TOR1A gene while others have mutations in both TOR1A and another DYT gene (THAP1 or SGCE).

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We propose a class of wavelength-division multiplexing (WDM) demultiplexers having a novel monitor and control scheme enabling dense WDM on Si nano-waveguide (NW) photonic integrated circuits (PICs), which had been impossible due to the critically small fabrication tolerance of the extremely miniaturized waveguide structure. With a computer simulation, we show our proposed demultiplexers enable crosstalk in the range of -50 to -40 dB, flat-topped spectrum for high spectral efficiency, and channel counts as large as 64. We have experimentally evaluated the validity of this type of demultiplexers by using a 4-ch WDM demultiplexer, which has shown total crosstalk of < -49 dB as a result of fully automatic control of heaters.

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Tuberous sclerosis complex (TSC) is an autosomal dominant hereditary disorder caused by mutations in either TSC1 on chromosome 16 or TSC2 on chromosome 9, clinically characterized mainly by facial angiofibroma, epilepsy, and intellectual disability. Cortical dysplasias, subependymal nodules, and subependymal giant cell astrocytoma are characteristic central nervous system lesions among 11 major features in the current clinical diagnostic criteria for TSC. We encountered an unusual case of genetically confirmed TSC1 presenting with symptomatic West syndrome due to an isolated cortical dysplasia in the left occipital lobe of a six-month-old male infant who did not meet the clinical diagnostic criteria for TSC.

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Article Synopsis
  • - Hypophosphatasia (HPP) is a rare genetic disorder caused by mutations in a specific gene, leading to symptoms like severe musculoskeletal pain, muscle weakness, and early tooth loss.
  • - A case study of a 32-year-old woman with childhood-onset HPP showed significant impairment in daily activities and the need for assistance with housework and child-rearing.
  • - Treatment with the drug asfotase alfa resulted in notable improvements in muscle strength and reduced pain, validated by standardized tests commonly used for other muscular disorders, suggesting these assessments could also be useful for HPP.
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Synopsis of recent research by authors named "Tomoyuki Akiyama"

  • Recent research by Tomoyuki Akiyama focuses primarily on epilepsy-related conditions in pediatric patients, exploring various aspects such as post-operative recovery, treatment efficacy, and metabolic indicators associated with seizures.
  • His studies examine innovative therapeutic approaches, including the use of alectinib post-transplant and the effectiveness of the ketogenic diet in managing drug-resistant epilepsy, revealing the complexities of treatment outcomes and metabolic changes.
  • Additionally, Akiyama investigates the role of genetic mutations in conditions such as myoclonus epilepsy and hypophosphatasia, contributing to a deeper understanding of the interplay between genetic factors and neurological disorders in children.