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Dive into the research topics where Yasutaka Toyota is active.

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Featured researches published by Yasutaka Toyota.


Dementia and Geriatric Cognitive Disorders | 2007

Caregiver burden associated with behavioral and psychological symptoms of dementia in elderly people in the local community

Naomi Matsumoto; Manabu Ikeda; Ryuji Fukuhara; Shunichiro Shinagawa; Tomohisa Ishikawa; Takaaki Mori; Yasutaka Toyota; Teruhisa Matsumoto; Hiroyoshi Adachi; Nobutsugu Hirono; Hirotaka Tanabe

Background: Despite many studies about the association between caregiver burden and behavioral and psychological symptoms of dementia (BPSD), there have been no population-based studies to evaluate caregiver burden associated with each BPSD. Objective: To evaluate caregiver burden associated with the individual BPSD in elderly people living in the community. Methods: The subjects were 67 participants with dementia living with their caregivers (diagnosed in the third Nakayama study): 51 Alzheimer’s disease, 5 vascular dementia and 11 other. The Neuropsychiatric Inventory (NPI) and NPI Caregiver Distress Scale (NPI-D) were used to assess subjects’ BPSD and related caregiver distress, respectively. Results: In the subjects exhibiting BPSD, aberrant motor behavior had the highest mean NPI score, and depression/dysphoria had the lowest. Agitation/aggression had the highest mean NPI-D score, and euphoria/elation had the lowest. Delusion, agitation/aggression, apathy/indifference, irritability/lability and aberrant motor behavior showed a correlation between the NPI and NPI-D scores. Conclusion: The burden associated with BPSD is different for each symptom and does not always depend on frequency and severity of BPSD. These findings suggest that some symptoms, such as agitation/aggression and irritability/lability, may affect the caregivers significantly, although their frequency and severity are low.


Dementia and Geriatric Cognitive Disorders | 2007

Frequency and Clinical Characteristics of Early-Onset Dementia in Consecutive Patients in a Memory Clinic

Shunichiro Shinagawa; Manabu Ikeda; Yasutaka Toyota; Teruhisa Matsumoto; Naomi Matsumoto; Takaaki Mori; Tomohisa Ishikawa; Ryuji Fukuhara; Kenjiro Komori; Kazuhiko Hokoishi; Hirotaka Tanabe

Aims: To investigate the frequency, rate of causes of dementia, and clinical characteristics of early-onset dementia in consecutive patients of a memory clinic. Methods: A total of 668 consecutive demented patients were involved in this study. We examined the distribution of patients’ diagnosis, differences in sex, education, dementia severity and cognitive function at the first visit, and the duration from onset to consultation. We also examined the changes in the proportion of subjects during the research period. Results: There were 185 early-onset patients, 28% of all demented patients. No significant differences were observed between the early-onset and late-onset dementia groups in Clinical Dementia Rating and Mini-Mental State Examination score at the first consultation, but the duration from onset to consultation was significantly longer in the early-onset group. In the early-onset group, the rates of patients with Alzheimer’s disease and dementia with Lewy bodies were relatively low and the rate of patients with frontotemporal lobar degeneration was relatively high. There were no significant differences in the proportion between either demented subjects and nondemented subjects or early-onset dementia patients and late-onset dementia patients during the research period. Conclusion: We conclude that early-onset dementia is not rare and its clinical characteristics and causes are different from late-onset dementia.


Dementia and Geriatric Cognitive Disorders | 2008

Cognitive function and psychiatric symptoms in early- and late-onset frontotemporal dementia.

Shunichiro Shinagawa; Yasutaka Toyota; Tomohisa Ishikawa; Ryuji Fukuhara; Kazuhiko Hokoishi; Kenjiro Komori; Satoshi Tanimukai; Manabu Ikeda

Background/Aim: Some recent studies mentioned that late-onset frontotemporal dementia (FTD) is more common than previously assumed. Although much research has been done in the field, there are no systematic studies which have compared clinical characteristics of early- and late-onset FTD. The aim of this study was to compare cognitive function and psychiatric symptoms in patients with early- and late-onset FTD. Methods: Study participants were consecutive outpatients. There were 35 FTD patients; their mean age at onset was 63.0 years. We studied sex, education, duration from onset to consultation, Clinical Dementia Rating (CDR) scores, Mini-Mental State Examination (MMSE) scores, Raven’s Coloured Progressive Matrices (RCPM) scores, and Neuropsychiatric Inventory (NPI) scores at first consultation of early- and late-onset FTD patients. Results: There were no significant differences in sex ratio, education, CDR scores, and duration from onset to consultation. There were significant differences in the total MMSE scores, ‘three-word recall task’, ‘construction task’, and RCPM scores; late-onset groups scored significantly lower than early-onset groups. There were significant differences in the apathy domain of NPI and total NPI scores; late-onset groups scored significantly higher than early-onset groups. Conclusion: Late-onset FTD patients may have memory and visuospatial deficits in addition to their behavioural changes, even if they are clinically diagnosed according to consensus diagnostic criteria. They also present more apathy, and they may have a different histolopathological background.


Dementia and Geriatric Cognitive Disorders | 2010

Transition of Distinctive Symptoms of Semantic Dementia during Longitudinal Clinical Observation

Tetsuo Kashibayashi; Manabu Ikeda; Kenjiro Komori; Shunichiro Shinagawa; Hideaki Shimizu; Yasutaka Toyota; Takaaki Mori; Tomohisa Ishikawa; Ryuji Fukuhara; Shu-ichi Ueno; Satoshi Tanimukai

Background/Aims: The aim of this study is to examine the clinical symptoms in a number of semantic dementia (SD) patients and to reveal the longitudinal progression and clinical course of these distinctive symptoms of SD. Methods: 19 consecutive SD patients were examined. Symptoms were classified into 23 distinct categories: behavioral symptoms, language and cognitive symptoms and symptoms concerning the impairment of activities of daily living (ADL). We divided patients into two subgroups, left- and right-dominant SD, and compared the onset of each symptom. Results: Language impairments occurred as the initial symptom in 16 cases. At the first examination, all cases showed both anomia and impairment of word comprehension. By around 3 years after onset, almost all language impairments were observed. Approximately 3–5 years after onset, prosopagnosia and behavioral symptoms appeared. Around the period when the loss of the language faculty and apathy became remarkable, impairment of ADL appeared. Patients spent all day in bed at this stage. Moreover, prosopagnosia appeared significantly earlier in right-dominant SD. Conclusion: Our findings clarify the progression of distinctive symptoms of SD patients. It is necessary to create a treatment strategy for SD patients with such a disease-specific course of SD.


Psychiatry and Clinical Neurosciences | 2013

Comparison of the utility of everyday memory test and the alzheimer's disease assessment scale-cognitive part for evaluation of mild cognitive impairment and very mild Alzheimer's disease

Hiroyoshi Adachi; Shunichiro Shinagawa; Kenjiro Komori; Yasutaka Toyota; Takaaki Mori; Teruhisa Matsumoto; Naomi Sonobe; Tetsuo Kashibayashi; Tomohisa Ishikawa; Ryuji Fukuhara; Manabu Ikeda

The purpose of this study was to compare the utility of the Rivermead Behavioural Memory Test (RBMT) and the Alzheimers Disease Assessment Scale‐Cognitive part (ADAS‐Cog) for the evaluation of mild cognitive impairment (MCI) or very mild Alzheimers disease (AD).


Psychogeriatrics | 2011

Clinical profiles of late-onset semantic dementia, compared with early-onset semantic dementia and late-onset Alzheimer's disease

Hideaki Shimizu; Kenjiro Komori; Ryuji Fukuhara; Shunichiro Shinagawa; Yasutaka Toyota; Tetsuo Kashibayashi; Naomi Sonobe; Teruhisa Matsumoto; Takaaki Mori; Tomohisa Ishikawa; Kazuhiko Hokoishi; Satoshi Tanimukai; Shu-ichi Ueno; Manabu Ikeda

Background:  Semantic dementia (SD) has been recognized as a representative of dementia with presenile onset; however, recent epidemiological studies have shown that SD also occurs in the elderly. There have been few studies about the differences of clinical profiles between early‐onset SD (EO‐SD) and late‐onset SD (LO‐SD). Age‐associated changes in the brain might cause some additional cognitive and behavioural profiles of LO‐SD in contrast to the typical EO‐SD cases. The aim of the present study was to clarify the characteristics of neuropsychological, and behavioural and psychological symptoms of dementia (BPSD) profiles of LO‐SD patients observed in screening tests in comparison with EO‐SD patients and late‐onset Alzheimers disease (LO‐AD) patients as controls.


International Psychogeriatrics | 2011

Risk of progression from mild memory impairment to clinically diagnosable Alzheimer's disease in a Japanese community (from the Nakayama Study).

Naomi Sonobe; Ryuji Hata; Tomohisa Ishikawa; Kantaro Sonobe; Teruhisa Matsumoto; Yasutaka Toyota; Takaaki Mori; Ryuji Fukuhara; Kenjiro Komori; Shu-ichi Ueno; Satoshi Tanimukai; Manabu Ikeda

BACKGROUND Memory impairment has been proposed as the most common early sign of Alzheimers disease (AD). The aims of this work were to evaluate the risk of progression from mild memory impairment/no dementia (MMI/ND) to clinically diagnosable AD in a community-based prospective cohort and to establish the risk factors for progression from MMI/ND to AD in the elderly. METHODS Elderly subjects aged over 65 years were selected from the participants in the first Nakayama study. MMI/ND was defined as memory deficit on objective memory assessment, without dementia, impairment of general cognitive function, or disability in activities of daily living. A total of 104 MMI/ND subjects selected from 1242 community-dwellers were followed longitudinally for five years. RESULTS During the five-year follow-up, 11 (10.6%) subjects were diagnosed with AD, five (4.8%) with vascular dementia (VaD), and six (5.8%) with dementia of other etiology. Logistic regression analysis revealed that diabetes mellitus (DM) and a family history of dementia (within third-degree relatives) were positively associated with progression to AD, while no factor was significantly associated with progression to VaD or all types of dementia. CONCLUSIONS DM and a family history of dementia were significant risk factors for progression from MMI/ND to clinically diagnosable AD in the elderly in a Japanese community.


Mitochondrion | 2012

Heteroplasmic m.1624C>T mutation of the mitochondrial tRNAVal gene in a proband and his mother with repeated consciousness disturbances

Yoko Sangatsuda; Masayuki Nakamura; Akiyuki Tomiyasu; Akiko Deguchi; Yasutaka Toyota; Yu-ichi Goto; Ichizo Nishino; Shu-ichi Ueno; Akira Sano

Homoplasmic m.1624C>T mutation of the mitochondrial tRNA(Val) gene was previously demonstrated to cause fatal neonatal Leigh syndrome. Here, we report the clinical phenotypes of a Japanese male and his mother with heteroplasmic m.1624C>T mutation. The 36-year-old male presented with repeated episodes of consciousness disturbance since the age of 25, cognitive decline, and personality change. Cerebrospinal fluid levels of lactate and pyruvate were elevated. His mother showed similar symptoms and course. The mutation m.1624C>T was identified heteroplasmically in the probands muscle and leukocytes and in the mothers leukocytes. The heteroplasmy load decreased with age.


Clinical Psychopharmacology and Neuroscience | 2017

Improvement of Visuo-spatial Function Assessed by Raven’s Colored Progressive Matrices in Dementia with Lewy Bodies by Donepezil Treatment

Yuta Yoshino; Takaaki Mori; Taku Yoshida; Yasutaka Toyota; Hideaki Shimizu; Jun-ichi Iga; Shusaku Nishitani; Shu-ichi Ueno

Objective Donepezil is used to improve cognitive impairment of dementia with Lewy bodies (DLB). Visuo-spatial dysfunction is a well-known symptom of DLB. Non-verbal Raven’s Colored Progressive Matrices (RCPM) were used to assess both visual perception and reasoning ability in DLB subjects treated with donepezil. Methods Twenty-one DLB patients (mean age, 78.7±4.5 years) were enrolled. RCPM assessment was performed at the time of starting donepezil and within one year after starting donepezil. Results There were significant improvements of RCPM in the total scores between one year donepezil treatment (p=0.013), in both Set A score (p=0.002) and Set AB score (p=0.015), but trend in the Set B score (p=0.083). Conclusion Donepezil is useful for improving visuo-spatial impairment in DLB, but not for problem-solving impairment.


International Journal of Geriatric Psychiatry | 2007

Comparison of behavioral and psychological symptoms in early-onset and late-onset Alzheimer's disease.

Yasutaka Toyota; Manabu Ikeda; Shunichiro Shinagawa; Teruhisa Matsumoto; Naomi Matsumoto; Kazuhiko Hokoishi; Ryuji Fukuhara; Tomohisa Ishikawa; Takaaki Mori; Hiroyoshi Adachi; Kenjiro Komori; Hirotaka Tanabe

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Shunichiro Shinagawa

Jikei University School of Medicine

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