Publications by authors named "Takeshi Ikeuchi"

Background: Progressive supranuclear palsy (PSP) is a major atypical parkinsonism. Because diagnosis based on the cardinal clinical features is often difficult, misdiagnosis with Parkinson's disease (PD) and multiple system atrophy (MSA) is common in PSP patients. Iron metabolism genes are reportedly involved in tau-accumulating neuronal cell death and ferroptosis in PSP, which is more severe than PD and MSA.

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Introduction: The SORL1 locus exhibits protective effects against Alzheimer's disease (AD) across ancestries, yet systematic studies in diverse populations are sparse.

Methods: Logistic regression identified AD-associated SORL1 haplotypes in East Asian (N = 5249) and European (N = 8588) populations. Association analysis between SORL1 haplotypes and AD-associated traits or plasma biomarkers was conducted.

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  • Bryant-Li-Bhoj syndrome (BLBS) is a genetic disorder linked to mutations in the H3F3A and H3F3B genes, leading to developmental issues and physical abnormalities.
  • A Japanese patient was identified with a new variant (p.A48G) in the H3F3A gene, showcasing additional symptoms not previously associated with BLBS, specifically neonatal myoclonus.
  • This case expands our understanding of the range of symptoms associated with BLBS, highlighting the variability in how the syndrome can manifest.
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Disease-modifying therapies for Alzheimer's disease (AD) are likely to be most beneficial when initiated in the presymptomatic phase. To track the benefit of such interventions, fluid biomarkers are of great importance, with neurofilament light chain protein (NfL) showing promise for monitoring neurodegeneration and predicting cognitive outcomes. Here, we update and complement previous findings from the Dominantly Inherited Alzheimer Network Observational Study by using matched cross-sectional and longitudinal cerebrospinal fluid (CSF) and plasma samples from 567 individuals, allowing timely comparative analyses of CSF and blood trajectories across the entire disease spectrum.

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  • A multicenter study in Japan began in 2014 to gather data on progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) to better understand their clinical features and identify potential biomarkers.
  • Initial assessments of 349 patients focused on symptoms, clinical scores (like the PSPRS), and factors affecting disease progression over eight years.
  • Results indicated that patients with Richardson's syndrome (RS) had better clinical scores compared to those with CBD, and cognitive dysfunction played a significant role in disease severity and progression.
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Clinical diagnosis of progressive supranuclear palsy (PSP) is difficult due to various phenotypes. Neuropathologically, PSP is defined by neuronal loss in the basal ganglia and brainstem with widespread occurrence of neurofibrillary tangles (NFTs) and accumulation of phosphorylated tau protein in neurons and glial cells in the brain. We previously identified the point mutation p.

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The clinical and neuropathological characteristics of progressive supranuclear palsy (PSP) with preservation of levodopa (L-dopa) response are described in this report. We present the case of a 73-year-old Japanese man with a 13-year history of dopa-responsive Parkinsonism and abnormalities observed in metaiodobenzylguanidine (MIBG) myocardial scintigraphy, suggesting Parkinson's disease. However, autopsy results revealed PSP pathology, including tuft-shaped astrocytes and globose-type neurofibrillary tangles, without Lewy body pathology.

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Blood biomarkers are minimally invasive, are available at a relatively low cost, and are easily accessible; therefore, they are expected to play a pivotal role in the diagnosis of dementia. Measurement of the amyloid-β ratio and phosphorylated tau in plasma has shown high potential for accurate detection of brain pathology in patients with Alzheimer's disease. Studies have investigated blood biomarkers that reflect neurodegeneration and neuroinflammation in patients with dementia.

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This study aimed to clarify associations of clinical and neuropsychological features and change in regional cerebral blood flow (rCBF) on I-IMP-SPECT in patients with Parkinson's disease (PD) who developed dementia. Sixty-one PD patients (mean age, 65.9 ± 8.

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This manuscript describes and summarizes the Dominantly Inherited Alzheimer Network Observational Study (DIAN Obs), highlighting the wealth of longitudinal data, samples, and results from this human cohort study of brain aging and a rare monogenic form of Alzheimer's disease (AD). DIAN Obs is an international collaborative longitudinal study initiated in 2008 with support from the National Institute on Aging (NIA), designed to obtain comprehensive and uniform data on brain biology and function in individuals at risk for autosomal dominant AD (ADAD). ADAD gene mutations in the amyloid protein precursor (), presenilin 1 (), or presenilin 2 () genes are deterministic causes of ADAD, with virtually full penetrance, and a predictable age at symptomatic onset.

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This study explored the role of the ubiquitin-proteasome system (UPS) in dominantly inherited Alzheimer's disease (DIAD) by examining changes in cerebrospinal fluid (CSF) levels of UPS proteins along with disease progression, AD imaging biomarkers (PiB PET, tau PET), neurodegeneration imaging measures (MRI, FDG PET), and Clinical Dementia Rating (CDR). Using the SOMAscan assay, we detected subtle increases in specific ubiquitin enzymes associated with proteostasis in mutation carriers (MCs) up to two decades before the estimated symptom onset. This was followed by more pronounced elevations of UPS-activating enzymes, including E2 and E3 proteins, and ubiquitin-related modifiers.

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  • Agyrophilic grains (AGs) are brain lesions that accumulate four-repeat tau and are linked to age-related cognitive decline, but their role in dementia remains uncertain due to conflicting research.
  • A study analyzed 30 cases of pure argyrophilic grain disease (pAGD) and 34 control cases to assess the quantity and distribution of Gallyas-positive AGs and associated neuronal loss in various brain regions.
  • Results indicated that higher concentrations of AGs in the amygdala and hippocampus significantly correlated with neuronal loss and affected dementia independently of other factors like age and other neurodegenerative stages.
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  • - The study investigates how well conventional MRI can differentiate corticobasal degeneration (CBD) from its mimics due to similar clinical features.
  • - Researchers analyzed the degree of brain atrophy and asymmetry in MRI images of 19 CBD patients and 16 patients with conditions that mimic CBD, like Alzheimer's and progressive supranuclear palsy.
  • - Findings suggest that specific patterns of atrophy and the presence of white matter hyperintensity can be used as imaging biomarkers to help diagnose CBD more accurately.
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Background: Positron emission tomography, which assesses the binding of translocator protein radiotracers, C-DPA-713, may be a sensitive method for determining glial-mediated neuroinflammation levels. This study investigated the relationship between regional C-DPA713 binding potential (BP) and anxiety in patients with Alzheimer's disease (AD) continuum.

Methods: Nineteen patients with AD continuum determined to be amyloid-/p-tau 181-positive via cerebrospinal fluid analysis were included in this cross-sectional study (mild cognitive impairment [MCI, n = 5] and AD [n = 14]).

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Background: Maximizing the efficiency to screen amyloid-positive individuals in asymptomatic and non-demented aged population using blood-based biomarkers is essential for future success of clinical trials in the early stage of Alzheimer's disease (AD). In this study, we elucidate the utility of combination of plasma amyloid-β (Aβ)-related biomarkers and tau phosphorylated at threonine 217 (p-tau217) to predict abnormal Aβ-positron emission tomography (PET) in the preclinical and prodromal AD.

Methods: We designed the cross-sectional study including two ethnically distinct cohorts, the Japanese trial-ready cohort for preclinica and prodromal AD (J-TRC) and the Swedish BioFINDER study.

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  • The study focuses on adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP), a rare and severe neurodegenerative disease, emphasizing the importance of prompt and precise diagnosis due to its progressive nature.
  • A review of 291 ALSP cases revealed that only 24.7% received an accurate initial diagnosis, with common misdiagnoses including frontotemporal dementia and multiple sclerosis.
  • The analysis also identified demographic and clinical variations that influenced initial misdiagnosis, highlighting a strong family history in 59.1% of patients and a significant portion presenting with cognitive or psychiatric symptoms.
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Background: Polygenic effects have been proposed to account for some disease phenotypes; these effects are calculated as a polygenic risk score (PRS). This score is correlated with Alzheimer's disease (AD)-related phenotypes, such as biomarker abnormalities and brain atrophy, and is associated with conversion from mild cognitive impairment (MCI) to AD. However, the AD PRS has been examined mainly in Europeans, and owing to differences in genetic structure and lifestyle, it is unclear whether the same relationships between the PRS and AD-related phenotypes exist in non-European populations.

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  • A 44-year-old woman with Lynch syndrome was treated for recurring rectal cancer that had spread to her peritoneum and caused complications like hydronephrosis and a urinary tract infection.
  • Initial treatment with pembrolizumab (an immunotherapy) led to significant shrinkage of the tumor and allowed for a subsequent surgery where the metastasis was successfully removed without needing to sacrifice the left ureter.
  • This case highlights a successful use of pembrolizumab to convert an initially unresectable tumor to a resectable one, marking a significant advancement in treatment for similar cases.
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Cardiospondylocarpofacial syndrome (CSCFS) is a congenital malformation characterized by growth retardation, facial features, short toes with carpal and tarsal fusion, extensive posterior neck vertebral fusion, congenital heart disease, and deafness. Here, we report a severe case of CSCFS with a novel variant, p.Thr187Ile, in MAP3K7.

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Neurocutaneous melanosis (NCM) is a rare congenital neurocutaneous syndrome characterized by congenital melanocytic nevus of skin and abnormal proliferation of leptomeningeal melanocytes. Early acquisition of post-zygotic somatic mutations has been postulated to underlie the pathogenesis of NCM. The pathogenesis of NCM remains to be fully elucidated, and treatment options have not been established.

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