Naoki Saji

National Center for Geriatrics and Gerontology | NCGG · Center for Comprehensive Care and Research on Memory Disorders

Introduction Sensory dysfunctions and cognitive impairments are related to each other. Although a relationship between tinnitus and subjective olfactory dysfunction has been reported, there have been no reports investigating the relationship between tinnitus and olfactory test results. Methods To investigate the relationship between tinnitus and o...

Aims/introduction: To investigate the changes in the glycated hemoglobin (HbA1c) levels and the relative status of the glycemic control related to the new glycemic targets recommended by the Japan Diabetes Society/Japan Geriatrics Society Joint Committee in 2016 in patients with diabetes mellitus visiting a memory clinic from 2012 to 2020. Materi...

Aim: Olfactory impairment is associated with cognitive impairment. However, differences between subjective and objective olfactory impairment measurements in older adults and their relationship with cognitive impairment are unclear. Methods: We assessed the relationship between cognitive and olfactory impairments via a single-center observationa...

Objective We aimed to evaluate the relationship between hearing ability and cognitive domains and determine how the relationship changes after 6 months of introducing a hearing aid. Methods We conducted a 6-month hearing aid lending study between September 2014 and March 2019, including 59 older participants who visited the Memory Clinic at the Na...

Objective White matter hyperintensity (WMH), defined as abnormal signals on magnetic resonance imaging (MRI), is an important clinical indicator of aging and dementia. Although MRI image analysis software can automatically detect WMH, the quantitative accuracy of periventricular hyperintensity (PVH) and deep white matter hyperintensity (DWMH) is un...

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune demyelinating disease of the central nervous system. Although recent reports have noted that cognitive impairment is common in NMOSD, little longitudinal information is available on the trajectories of cognitive function in the disease. Here, we report a case of a 55-year-old woman wit...

Background: With increasingly aging societies, a comprehensive strategy for dementia research is important. The Organized Registration for the Assessment of dementia by the Nationwide General consortium toward Effective treatment (ORANGE) Registry is the first longitudinal multicenter prospective trial-ready cohort in Japan. Objective: To establ...

Background & Aims While cross-sectional studies report associations between behavioral and psychological symptoms of dementia (BPSD) and nutritional status as a modifiable factor, their causal relationship remains unclear. Therefore, this study investigated the impact of nutritional status on BPSD. Methods This study included women with mild cogni...

Objective Dementia with Lewy bodies (DLB) is the second-most common form of neurodegenerative dementia after Alzheimer's disease (AD). Falls are a vital prognostic factor in patients with dementia and are a characteristic feature of DLB. This study investigated the screening potential of the fall risk evaluation for DLB and compared it with that of...

Background: The association of sarcopenia with cognitive function in its specific domains remains poorly understood. Objectives: To investigate the association of sarcopenia and its components with neuropsychological performance among patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD). Design: Cross-sectional design. S...

Background: Previous studies have demonstrated associations between gut microbiota, microbial metabolites, and cognitive decline. However, relationships between these factors and lipopolysaccharides (LPS; molecules of the outer membrane of gram-negative bacteria) remain controversial. Objective: To evaluate associations between plasma LPS, gut m...

Background: Previous studies have demonstrated associations between gut microbiota, microbial metabolites, and cognitive decline. However, relationships between these factors and neurofilament light chain (NfL; a disease-nonspecific biomarker of neural damage) remain controversial. Objective: To evaluate the associations between plasma NfL, gut...

A lower body mass is associated with the progression of Alzheimer's disease (AD) and the risk of mortality in patients with AD; however, evidence of genetic determinants of decreased body mass in cognitively impaired older adults is limited. We therefore investigated the genetic effect of APOE-ε4 on body composition in older adults with mild cognit...

Objective Previous studies have shown associations between the gut microbiota, microbial metabolites, and cognitive decline. However, the effect of the dietary composition on such associations has not been fully investigated. Methods We performed a cross-sectional sub-analysis of data from our prospective hospital-based cohort study. We assessed t...

Relationships between hearing impairment (HI) and dementia have been reported in elderly adults, and there is growing evidence that HI is an independent modifiable risk factor for dementia. However, there is insufficient evidence to recommend the use of hearing aids to reduce the risk of cognitive decline. To address these issues, we are currently...

Objective The influence of living alone on multiple food and nutrition behaviors across a range of ages and genders has not been sufficiently investigated. Moreover, no studies have described both dietary status and medical examination findings in persons living alone. We investigated dietary habits and medical examination findings in persons livin...

Existence of a relationship between hearing impairment (HI) and disability or dementia has been reported in older adults, and there is growing evidence to suggest that HI may be an independent modifiable risk factor for dementia. Nevertheless, there is insufficient evidence to recommend the use of hearing aids to reduce the risk of cognitive declin...

Background Previous studies have shown associations between the gut microbiota, microbial metabolites, and cognitive decline. However, the effect of the dietary composition on such associations has not been fully investigated. Methods We performed a cross-sectional sub-analysis of data from our prospective hospital-based cohort study (the Gimlet s...

Background Recent studies have demonstrated an association between the gut microbiome and cognitive function. However, the associations between the gut microbiome and brain parenchyma damage, and their underlying mechanisms, remain unclear. Materials and Methods We performed a cross-sectional sub-analysis using data from our prospective cohort stu...

Background Hearing impairment (HI) is associated with dementia. However, the cognitive screening tasks effective in older community dwellers presenting with HI are unclear. Methods We retrospectively and cross-sectionally investigated the associations between HI and cognitive function assessed with screening tasks using data from two healthcare ch...

Background: Very few studies have investigated the impact of cognitive frailty in clinical settings, especially in memory clinic populations. Objective: To examine the impact of cognitive frailty on activities of daily living (ADL), cognitive function, and conversion to dementia among memory clinic patients with mild cognitive impairment (MCI)....

Dysregulation of the gut microbiome is associated with dementia. However, the relationship between microbiome-associated metabolites and dementia has yet to be identified. Outpatients visiting a memory clinic in Japan enrolled in this cross-sectional study; 107 subjects were eligible for the study, 25 of which had dementia. We collected demographic...

Dysregulation of the gut microbiome is associated with several life-threatening conditions, and might therefore represent a useful target for the prevention of dementia. However, the relationship between the gut microbiome and dementia has not yet been fully elucidated. Here, we recruited outpatients visiting our memory clinic to participate in thi...

Recent studies have revealed an association between the dysregulation of the gut microbiome and dementia. However, whether this dysregulation is associated with mild cognitive impairment (MCI), an early stage of cognitive decline, in patients without dementia remains unclear. We performed a cross-sectional analysis to determine the association betw...

Background: Cognitive frailty (CF) is defined as simultaneous presence of physical frailty (PF) and cognitive impairment among older adults without dementia. Although white matter hyperintensities (WMH) as expressions of cerebral small vessel disease are associated with physical and cognitive decline and could manifest as CF, this association rema...

We examined the nutritional status and its association with behavioral psychiatric symptoms of dementia (BPSD) among 741 memory clinic patients (normal cognition (NC), 152; mild cognitive impairment (MCI), 271; early-stage Alzheimer disease (AD), 318). Nutritional status and BPSD were assessed using the Mini Nutritional Assessment Short-Form (MNA-S...

Background: The gut microbiota is associated with several life-threatening conditions andthus might represent a useful strategy for the prevention of dementia. However, the association between gut microbiota and dementia has not yet been fully clarified. Hypothesis: There are differences in the components of gut microbiota between demented and non-...

Dysregulation of the gut microbiome is associated with several life-threatening conditions and thus might represent a useful target for the prevention of dementia. However, the relationship between the gut microbial population and dementia has not yet been fully clarified. We recruited outpatients visiting our memory clinic to participate in this s...

Background: This study examined the relationship between olfactory function and taste function. A personal function test was calculated from the Yakumo study database, and the odour stick identification test and salt taste identification test were administered to healthy elderly people. The participants were community dwellers who voluntarily parti...

Objective: The aim of this study was to clarify the association of physical frailty with behavioral and psychological symptoms of dementia (BPSD) and caregiver burden in patients with Alzheimer's disease (AD). Methods: The subjects were 1,193 AD patients who presented to the Memory Clinic at the National Center for Geriatrics and Gerontology of...

Introduction Non-valvular atrial fibrillation (NVAF) is known as a robust risk factor for stroke. Recent reports have suggested a risk of dementia with NVAF, but much remains unknown regarding the relationship between this mechanism and the potential protective effects of novel anticoagulants (direct oral anticoagulants (DOACs), or non-vitamin K or...

The amount of attention to age-related hearing loss (ARHL) has been growing, not only from the perspective of being one of the most common health conditions affecting older adults, but also from the perspective of its relation to cognition. Results from a number of epidemiological and laboratory studies have demonstrated a significant link between...

Background/Aims Behavioral and psychological symptoms of dementia (BPSD) are exhibited in most patients with Alzheimer disease (AD). Although white matter hyperintensity (WMH) is often observed with AD, the precise role of WMH in BPSD remains unclear. The current study aimed to identify the impact of regional WMH on specific features of BPSD in per...

Since the operational definition of "cognitive frailty" was first proposed in 2013 by the International Academy of Nutrition and Aging and the International Association of Gerontology and Geriatrics, several studies have been carried out using this cognitive frailty model. In this review, we examined the available clinical and epidemiological evide...

Background: The mechanism of progressive neurological deficit in patients with recent small subcortical infarcts has not yet been clarified. Inflammatory biomarkers and the use of cilostazol may be associated with this phenomenon. Methods: Between May 2013 and April 2014, we evaluated consecutive first-ever patients with stroke due to recent sma...

Background: Weight loss is frequently observed in patients with Alzheimer's disease (AD); however, the underlying mechanisms are not well understood. Objects: To clarify the associations between nutritional status and AD-related brain changes using Pittsburgh Compound-B (PiB)-PET, fluorodeoxyglucose (FDG)-PET, and structural MRI. Methods: The...

Background Instrumental activities of daily living (IADL) start to decline during the progression of amnestic mild cognitive impairment (aMCI) to Alzheimer disease (AD). Cognitive and physical decline are involved in the loss of functional independence. However, little is known about AD-related neural change that leads to IADL impairment. The purpo...

Background: Urinary incontinence (UI) is frequently observed in patients with Alzheimer's disease (AD). Although previous works highlight the association between frontal lobe-related function and UI, causal relationship is unclear. Objects: To clarify the longitudinal association between frontal lobe function and the incidence of UI at 1 year in...

The aim of this study was to determine whether pulse wave velocity (PWV), a marker of vascular endothelial impairment and arteriosclerosis, predicts future ischemic stroke in patients who developed acute lacunar infarction. Patients with a first-ever ischemic stroke due to acute lacunar infarction were enrolled in this study. An oscillometric devic...

The safety and efficacy of non-vitamin K oral anticoagulant (NOAC) compared with warfarin in treating patients with non-valvular atrial fibrillation (NVAF) who developed acute ischemic stroke or transient ischemic attack (AIS/TIA), particularly those receiving tissue-plasminogen activator (tPA) therapy, remains unclear. Between April 2012 and Decem...

Background: The aim of the present study was to clarify the effect of glucose profiles after stroke, which was assessed by a continuous glucose monitoring (CGM) device. Methods: Acute ischemic stroke patients within 24 h of onset were prospectively studied. CGM was performed for 72 h after admission. CGM parameters were evaluated as follows: (1)...

We report the case of a 73-year-old man who developed bilateral vertebral artery dissection after a craniocervical contusion. He fell into a side ditch, and suffered bruising on the head and neck. He was diagnosed with a sixth cervical vertebral fracture, cerebellar infarction, and bilateral vertebral artery dissection, and was treated conservative...

Frailty is a predictor of functional decline, falls, hospitalization, and mortality. Fried et al. developed the frailty index, which include 5 simple items: weight loss, weakness, exhaustion, slowness, and low activity. Likewise, sarcopenia indicates an age-related decline in skeletal muscle mass as well as muscle function, which may result in redu...

Background: To date, very little is known about the nature of sarcopenia in subjects with cognitive impairment. The aims of this study were firstly to clarify the prevalence of sarcopenia at various stages of cognitive impairment, and secondly to examine factors related to sarcopenia in men and women with cognitive impairment. Method: The subjec...

A 64-year-old man developed right arm weakness and dysarthria, and was admitted to our hospital. Diffusion-weighted magnetic resonance imaging of the brain showed a high intensity area in the frontal lobe. T2*-weighted images showed multiple spotty low intensity lesions in bilateral cerebral hemispheres, mimicking cerebral microbleeds. Cerebral ang...

Background and purpose: Hyperintense vessels (HV) detected on fluid-attenuated inversion recovery (FLAIR) in patients with acute ischemic stroke (AIS) indicate cerebral hypoperfusion. However, the clinical meaning of changes in HV is yet to be clarified. Here, we investigated serial changes to HV in patients with AIS who received tissue plasminoge...

Background: Cerebral small vessel diseases, including silent lacunar infarcts, white matter hyperintensities, and microbleeds, pose a risk for cerebrovascular disease, cognitive impairment, and the geriatric syndrome via effects on arterial stiffness. However, the vascular, physiological, and metabolic roles of arterial stiffness in cerebral small...

White matter hyperintensities ( WMH ) are defined as cerebral white matter changes presumed to be of vascular origin, bilateral and mostly symmetrical. They can appear as hyperintense on T 2‐weighted and fluid‐attenuated inversion recovery sequences, and as isointense or hypointense on T 1‐weighted magnetic resonance imaging of the brain. WMH have...

Cerebral small-vessel disease (SVD) is associated with renal dysfunction such as chronic kidney disease. Although cerebral microbleeds (CMBs) are common in patients with acute lacunar infarcts (ALI), the association between renal dysfunction and CMBs in such patients remains unclear. Between April 2007 and March 2013, we evaluated consecutive first...

Hereditary cerebellar ataxia constitutes a heterogeneous group of neurodegenerative disorders, occasionally accompanied by other neurological features. Genetic defects remain to be elucidated in approximately 40% of hereditary cerebellar ataxia cases in Japan. We attempted to identify the gene responsible for autosomal recessive cerebellar ataxia w...

We herein report a case of ischemic stroke in a 69-year-old man with unilateral moyamoya vessels originating from the proximal portion of the left middle cerebral artery. In addition, digital-subtraction angiography demonstrated a string-of-beads-like appearance in the cavernous portion of the left internal carotid artery. A genetic analysis reveal...

Hereditary hemorrhagic telangiectasia (HHT) occasionally can be discovered in patients with cerebrovascular disease. Pulmonary arteriovenous malformation (PAVM) is one of the complications in HHT and occasionally is causative for life-threatening embolic stroke. Several genetic defects have been reported in patients with HHT. The broad spectrum of...

The ankle-brachial index (ABI), brachial-ankle pulse wave velocity (baPWV) and cardio-ankle vascular index (CAVI) are surrogate markers of arteriosclerosis. However, their roles in patients with acute ischemic stroke remain unclear. From October 2003 to September 2011, we enrolled patients with arteriosclerotic ischemic stroke (AIS) exhibiting larg...

Background: We conducted a multicenter retrospective cohort study to elucidate the characteristics of intracranial hemorrhage (ICH) in patients with atrial fibrillation treated with non-vitamin K antagonist oral anticoagulants (NOACs). Method and results: We sent a questionnaire to the directors of 241 stroke centers in Japan to establish the cl...

Background and Purpose: Hyperintense vessels (HV) on FLAIR detected in patients with acute ischemic stroke indicate cerebral hypoperfusion. Thus, vanishing of HV should indicate reperfusion. We investigated serial changes of HV in patients who received tissue plasminogen activator (t-PA) therapy, comparing changes with clinical outcomes. Methods: W...

Half of acute stroke patients have poor outcomes at 3months even when treated with intravenous thrombolysis using tissue-plasminogen activator (t-PA) therapy. The aim of the present study was to evaluate the impact of the susceptibility vessel sign (SVS) on magnetic resonance imaging (MRI) T2* at the proximal portion of the middle cerebral artery (...

Objective We investigated whether brain natriuretic peptide (BNP) levels could be used as a marker to predict recurrent stroke in ischemic stroke survivors. Methods From April 2007 to March 2011, consecutive patients within 24 hours of onset of ischemic stroke were prospectively enrolled, and admission plasma BNP levels were measured. Survivors we...

We report an IE-related stroke patient receiving hemodialysis with the ICA stenosis.•The ICA stenosis progressed in-situ, finally leading to occlusion.•Autopsy revealed multiple vegetations on the mitral valve and the ICA thrombus.•Platelet-rich thrombus with Gram-positive cocci was confirmed by pathological examination.•The patient had pyogenic ar...

Background: Intravenous thrombolysis using the tissue-type plasminogen activator (t-PA) is contraindicated for patients with a history of intracerebral hemorrhage (ICH). T2*-weighted magnetic resonance imaging (MRI) is able to detect asymptomatic ICH. If there is an association between asymptomatic ICH on T2* before t-PA therapy and ICH after t-PA...

Background: Whether brain natriuretic peptide (BNP) levels are associated with early recurrent stroke in cardioembolic stroke patients was investigated. Methods: From January 2010 to March 2014, consecutive patients within 24 hours of onset of cardioembolic stroke were prospectively enrolled, and admission plasma BNP levels were measured. Recurr...

Background: Chronic kidney disease (CKD) is associated with cerebral small vessel diseases (SVD) and predicts stroke, cardiovascular events and mortality. However, its association with recent small subcortical infarcts (RSSI), a novel subtype of cerebral SVD, has not yet been established in stroke patients. The aim of this longitudinal study was to...

Transient neurological attacks (TNAs) are attacks with temporary (< 24 h) neurological symptoms, and reported in 1975. Ischemic cerebral infarction often occurres after transient neurological symptoms which are not sometimes involved in transient ischemic attack (TIA) criteria. The purpose of this study was to clarity transient neurological symptom...