Ryoko Ihara
A5086245745- Dementia and Cognitive Impairment Research
- Alzheimer's disease research and treatments
- Functional Brain Connectivity Studies
- Parkinson's Disease Mechanisms and Treatments
- Neurological Disease Mechanisms and Treatments
- Amyotrophic Lateral Sclerosis Research
- Neurological disorders and treatments
- Advanced Neuroimaging Techniques and Applications
- Health Systems, Economic Evaluations, Quality of Life
- Advanced MRI Techniques and Applications
- Neuroinflammation and Neurodegeneration Mechanisms
- Prion Diseases and Protein Misfolding
- Botulinum Toxin and Related Neurological Disorders
- Bioinformatics and Genomic Networks
- Glioma Diagnosis and Treatment
- Health Literacy and Information Accessibility
- Nutrition, Genetics, and Disease
- Cancer-related gene regulation
- Health, Environment, Cognitive Aging
- Chronic Disease Management Strategies
- Antiplatelet Therapy and Cardiovascular Diseases
- RNA Research and Splicing
- Ethics in Clinical Research
- Cerebrospinal fluid and hydrocephalus
- Neurological Disorders and Treatments
Tokyo Metropolitan Institute of Gerontology
2023-2025
Tokyo Metropolitan Geriatric Hospital
2020-2024
San Francisco VA Medical Center
2024
University of California, San Francisco
2024
University of Tokyo Hospital
2014-2023
Center for Inherited Blood Disorders
2022
Neurology, Inc
2022
The University of Tokyo
2013-2021
Washington University in St. Louis
2017
Graduate School USA
2013
Therapeutic modulation of TREM2-dependent microglial function might provide an additional strategy to slow the progression Alzheimer's disease. Although studies in animal models suggest that TREM2 is protective against pathology, its effect on tau pathology and potential beneficial role people with disease still unclear. Our aim was study associations between dynamics soluble TREM2, as a biomarker signalling, amyloid β (Aβ) deposition, tau-related neuroimaging markers, cognitive decline,...
Abstract 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 early stage Alzheimer’s disease (AD). In this study, we elucidate utility combination plasma amyloid-β (Aβ)-related tau phosphorylated at threonine 217 (p-tau217) predict abnormal Aβ-positron emission tomography (PET) preclinical prodromal AD. Methods We designed cross-sectional...
Abstract Introduction We conducted Japanese Alzheimer's Disease Neuroimaging Initiative (J‐ADNI) and compared the basic characteristics progression profiles with those of ADNI in North America. Methods A total 537 subjects normal cognition, late amnestic mild cognitive impairment (LMCI), or disease (AD) were enrolled using same criteria as ADNI. Rates changes representative functional measures for amyloid positron emission tomography‐ cerebrospinal fluid β(1–42)‐positive LMCI AD between...
"Brain-predicted age" quantifies apparent brain age compared to normative neuroimaging trajectories. Advanced brain-predicted has been well established in symptomatic Alzheimer disease (AD), but is underexplored preclinical AD. Prior studies have typically used structural MRI, resting-state functional connectivity (FC) remains underexplored. Our model predicted from FC 391 cognitively normal, amyloid-negative controls (ages 18-89). We applied the trained 145 amyloid-negative, 151 AD, and 156...
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by progressive and selective loss of motor neurons. The discovery mutations in the gene encoding an RNA-binding protein, TAR DNA-binding protein 43 kD (TDP-43), familial ALS, strongly implicated abnormalities RNA processing pathogenesis although mechanisms whereby TDP-43 leads to neurodegeneration remain elusive. To clarify mechanism degeneration caused TDP-43, we generated transgenic Drosophila melanogaster...
<h3>Importance</h3> Allelic variation in the brain-derived neurotrophic factor (<i>BDNF</i>) Val66Met polymorphism moderates increases cerebrospinal fluid (CSF) levels of tau and phosphorylated 181 (p-tau181), measured using immunoassay, cognitive decline presymptomatic dominantly inherited Alzheimer disease (DIAD). Advances mass spectrometry show that CSF phosphorylation occupancy at threonine 217 (p-tau181/tau181, p-tau217/tau217) with initial β-amyloid (Aβ) aggregation, while 205...
Abstract Neurofilament light chain, a putative measure of neuronal damage, is measurable in blood and CSF predictive cognitive function individuals with Alzheimer’s disease. There has been limited prior work linking neurofilament functional connectivity, no investigated associations connectivity autosomal dominant Here, we assessed relationships between light, cognition, cross-sectional sample 106 disease mutation carriers 76 non-carriers. We employed an innovative network-level enrichment...
The APOE-ε4 allele(s) is a strong risk factor for Alzheimer's disease (AD). A significant point of access this allele testing through services provided by medical facilities in Japan, which advertise out-of-insurance APOE on their websites. There concern that website advertisements may influence the ability individuals to adequately self-determine whether undergo testing. We conducted cross-sectional survey facility websites Japan advertising genetic predefined desirable features...
A higher levodopa dose is a risk factor for motor complications in Parkinson's disease (PD). Istradefylline (IST) used as adjunctive treatment to PD patients with off episodes, but its impact on titration remains unclear. The objective of this study was investigate the effect IST escalation wearing-off. This multicenter, open-label, randomized, parallel-group controlled (ISTRA ADJUST PD) which experiencing wearing-off (n = 114) who were receiving 300–400 mg/day randomized receive or no...
Abstract Background PSEN1, PSEN2, and APP mutations cause Alzheimer’s disease (AD) with an early age at onset (AAO) progressive cognitive decline. PSEN1 are more common generally have earlier AAO; however, certain a later AAO, similar to those observed in PSEN2 . Methods We examined whether endotypes exist across these AAO (~ 55 years) using hiPSC-derived neurons from familial (FAD) patients harboring A79V , N141I V717I mechanistically characterized by integrating RNA-seq ATAC-seq. Results...
Lecanemab, an anti-amyloid therapy for early Alzheimer's disease, received approval by the FDA and Japan in 2023. Public response on social media was scrutinized, aiming to obtain insights into communication treatment development. For 478 posts from X Facebook, their sentiments efficacy, safety, societal significance, overall lecanemab impression were assessed GPT-4 authors. Results indicated impressions 43.7% negative, 26.6% neutral, 29.7% positive. Social significance concerns dominated...
Anosognosia, a lack of self-awareness regarding cognitive dysfunction, often accompanies the progression Alzheimer's disease (AD) pathology. This study explored relationship between AD pathology and anosognosia measured by discrepancies in Cognitive Function Instrument (CFI) scores, as rated participants their partners (SP). Using mixed-effects models on non-demented participant data, results revealed that lower self-reported CFI score compared to SP ratings was significantly associated with...
To the Editor: We have recently highlighted potential pitfalls of amyloid-beta (Aβ) PET, suggesting that both Aβ and tau assessments are necessary to relate clinical symptoms Alzheimer disease (AD) pathology.1 Herein, we would like present 3 additional cases related practice disease-modifying therapy (DMT) for AD. Lecanemab donanemab, which monoclonal antibodies directed against aggregated forms Aβ, currently available use as DMT under universal health insurance system in Japan. According...
The AT(N) classification was proposed for categorising individuals according to biomarkers. However, profiles may vary depending on the markers chosen and target population.We stratified 177 who participated in Japanese Alzheimer's Disease Neuroimaging Initiative by cerebrospinal fluid (CSF) We compared frequency of between using total tau neurofilament light chain (NfL) as N (AT(N)tau AT(N)NfL). Baseline characteristics, longitudinal biological clinical changes were examined profiles.We...
CSF tau phosphorylated at threonine 181 (p-tau181) is a widely used biomarker for Alzheimer disease (AD) and has recently been regarded to reflect β-amyloid and/or p-tau deposition in the AD brain. Neuronal intranuclear inclusion (NIID) neurodegenerative characterized by inclusions neurons, glial cells, other somatic cells. Symptoms include dementia, neuropathy, others. biomarkers were not reported. The objective of this study was investigate whether including p-tau181 are altered patients...
APOE -ε4 allele[s] is a risk factor for Alzheimer's disease (AD) and Amyloid-Related Imaging Abnormalities (ARIA) in anti-amyloid beta therapy, also associated with cerebrovascular factors such as hyperlipidemia or atherosclerosis. During AD clinical trials, carriers may experience neuropsychiatric adverse events (AEs) related to these risks, complicating the differentiation of ARIA from based on symptoms. This study aimed examine hypothetical impact considering allele's non-ARIA AEs during...
Abstract Introduction Possession of the apolipoprotein E ( APO ) ε4 allele advances amyloid β (Aβ) deposition and symptomatic onset Alzheimer's disease (AD), whereas its effect on rate cognitive decline remained controversial. We examined effects APOE cognition in biomarker‐confirmed late mild impairment (LMCI) AD subjects Japanese Disease Neuroimaging Initiative (J‐ADNI) North American ADNI (NA‐ADNI). Methods The “early AD” (ie, combined LMCI AD) cohort 649 from J‐ADNI NA‐ADNI were selected...
Objective To characterize the pattern of neuron loss in hippocampal sclerosis aging (HS‐Aging) and age‐related diseases to evaluate its contribution cognitive impairment elderly. Methods Participants (n = 1,361) came from longitudinal observational studies at Knight Alzheimer Disease Research Center, Washington University (St. Louis, MO). Relative hippocampus HS‐Aging was measured using unbiased stereological methods. Transactive response DNA‐binding protein 43 kDa (TDP‐43) proteinopathy, a...