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Background: Both late-life depression (LLD) and short sleep duration increase the risk of cognitive impairment. Increased insular resting-state functional connectivity (FC) has been reported in individuals with short sleep duration and dementia. Objective: This study aimed to investigate whether short sleep duration is associated with impaired cognition and higher insular FC in patients with LLD. Methods: This case– control study recruited 186 patients with LLD and 83 normal controls (NC), and comprehensive psychometric assessments, sleep duration reports and resting-state functional MRI scans (81 LLD patients and 54 NC) were conducted. Results: Patients with LLD and short sleep duration (LLD-SS patients) exhibited more severe depressive symptoms and worse cognitive function than those with normal sleep duration (LLD-NS patients) and NC. LLD-SS patients exhibited higher FC between the bilateral insula and inferior frontal gyrus (IFG) pars triangularis than LLD-NS patients and NC, while LLD-NS patients exhibited lower FC than NC. Increased insular FC was correlated with short sleep duration, severe depressive symptoms, and slower information processing speeds. Furthermore, an additive effect was found between sleep duration and LLD on global cognition and insular FC. Conclusion: LLD-SS patients exhibited impaired cognition and increased insular FC. Abnormal FC in LLD-SS patients may be a therapeutic target for neuromodulation to improve sleep and cognitive performance and thus decrease the risk of dementia. [ABSTRACT FROM AUTHOR]

Aims: The present study aimed to compare temporal variability in the spontaneous fluctuations of activity and connectivity between amnestic MCI (aMCI) and nonamnestic MCI (naMCI), which enhances the understanding of their different pathophysiologies and provides targets for individualized intervention. Methods: Sixty‐five naMCI and 48 aMCI subjects and 75 healthy controls were recruited. A sliding window analysis was used to evaluate the dynamic amplitude of low‐frequency fluctuations (dALFF), dynamic regional homogeneity (dReHo), and dynamic functional connectivity (dFC). The caudal/rostral hippocampus was selected as the seeds for calculating dFC. Results: Both aMCI and naMCI exhibited abnormal dALFF, dReHo, and hippocampal dFC compared with healthy controls. Compared with individuals with naMCI, those with aMCI exhibited (1) higher dALFF variability in the right putamen, left Rolandic operculum, and right middle cingulum, (2) lower dReHo variability in the right superior parietal lobule, and (3) lower dFC variability between the hippocampus and other regions (left superior occipital gyrus, middle frontal gyrus, inferior cerebellum, precuneus, and right superior frontal gyrus). Additionally, variability in dALFF, dReHo, and hippocampal dFC exhibited different associations with cognitive scores in aMCI and naMCI patients, respectively. Finally, dReHo variability in the right superior parietal lobule and dFC variability between the right caudal hippocampus and left inferior cerebellum exhibited partially mediated effects on the different memory scores between people with aMCI and naMCI. Conclusion: The aMCI and naMCI patients exhibited shared and specific patterns of dynamic brain activity and connectivity. The dReHo of the superior parietal lobule and dFC of the hippocampus‐cerebellum contributed to the memory heterogeneity of MCI subtypes. Analyzing the temporal variability in the spontaneous fluctuations of brain activity and connectivity provided a new perspective for exploring the different pathophysiological mechanisms in MCI subtypes. [ABSTRACT FROM AUTHOR]

Background Odor identification (OI) dysfunction is an early marker of Alzheimer's disease (AD), but it remains unclear how olfactory-related regions change from stages of subjective cognitive decline (SCD) and mild cognitive impairment (MCI) to AD dementia. Methods Two hundred and sixty-nine individuals were recruited in the present study. The olfactory-related regions were defined as the regions of interest, and the grey matter volume (GMV), low-frequency fluctuation, regional homogeneity (ReHo), and functional connectivity (FC) were compared for exploring the changing pattern of structural and functional abnormalities across AD, MCI, SCD, and normal controls. Results From the SCD, MCI to AD groups, the reduced GMV, increased low-frequency fluctuation, increased ReHo, and reduced FC of olfactory-related regions became increasingly severe, and only the degree of reduced GMV of hippocampus and caudate nucleus clearly distinguished the 3 groups. SCD participants exhibited reduced GMV (hippocampus, etc.), increased ReHo (caudate nucleus), and reduced FC (hippocampus-hippocampus and hippocampus-parahippocampus) in olfactory-related regions compared with normal controls. Additionally, reduced GMV of the bilateral hippocampus and increased ReHo of the right caudate nucleus were associated with OI dysfunction and global cognitive impairment, and they exhibited partially mediated effects on the relationships between OI and global cognition across all participants. Conclusion Structural and functional abnormalities of olfactory-related regions present early with SCD and deepen with disease severity in the AD spectrum. The hippocampus and caudate nucleus may be the hub joining OI and cognitive function in the AD spectrum. [ABSTRACT FROM AUTHOR]

Background: Late-life depression (LLD) is a risk factor for cognitive decline in older adults, and odor identification (OI) deficits are an early indicator of cognitive decline with LLD. However, neuropsychiatric symptoms (NPSs) are common in LLD and are associated with OI deficits. In subjects with LLD, when OI deficits forecast cognitive decline, whether and how NPS affects the relationship between OI and cognition still must be further explored. Objective: To comprehensively explore the potential effects of various NPSs on the relationship between OI and cognition in participants with LLD. Methods: There were 167 patients with LLD and 105 normal elderly (NE) participants. The odor identification test (Sniffin' Sticks), cognitive function assessments (global cognition, memory, executive function, attention, language, visual space), and an NPS assessment (the neuropsychiatric inventory questionnaire) were performed on the subjects. In patients with LLD, the relationship among OI, cognition and NPSs was examined using correlation analysis and moderation analysis. Results: In patients with LLD, OI was positively correlated with cognition (global cognition, memory, executive function, attention, language) and negatively associated with NPSs (agitation and aberrant motor behavior). In NE group, OI was correlated with executive function. Moderation analysis showed that there was an interactive effect of agitation and cognitive impairment (language deficit or attention deficit) on OI in patients with LLD. Conclusion: The coexistence of agitation and language or attention deficit was associated with worse OI in subjects with LLD. Agitation should be considered since OI predicts cognitive decline in patients with LLD. [ABSTRACT FROM AUTHOR]

Background: Odor identification dysfunction is an early predictor of the development of Alzheimer's disease (AD), but neuropsychiatric symptoms (NPS), which are common in AD and mild cognitive impairment (MCI), are also associated with odor identification dysfunction. Whether NPS affect the specificity of using odor identification dysfunction to predict cognitive decline in AD and MCI remains unclear. Methods: Patients (233 with MCI and 45 with AD) and 45 healthy controls (HCs) underwent assessments of odor identification (Sniffin' Sticks), NPS (Neuropsychiatric Inventory-12), and cognitive function (global cognition, memory, language, executive function, visual-spatial skill, and attention). Structural equation modeling (SEM) with bootstrapping estimation was conducted to explore the relationships between odor identification, NPS, and cognition. Results: Patients with NPS showed significantly worse performance in odor identification and cognition than patients without NPS and HCs. The SEM showed odor identification to be positively associated with cognition, and cognition had special indirect effects on odor identification through affective and psychosis symptoms (two factors extracted from Neuropsychiatric Inventory-12). Additionally, affective and psychosis symptoms partially mediated the effect of cognition on odor identification. Conclusion: Neuropsychiatric symptoms are associated with odor identification dysfunction in patients with AD and MCI. Studies exploring the relationship between odor identification dysfunction and cognitive decline in patients with AD and MCI should include an assessment of affective and psychosis symptoms, and adjust their confounding effects. [ABSTRACT FROM AUTHOR]

Background: Odor identification dysfunction occurs early in Alzheimer's disease (AD) and is considered a preclinical symptom along with subjective cognitive decline (SCD). Nevertheless, whether subjects with SCD are co-symptomatic with odor identification dysfunction remains unclear.Objective: To compare the degree of odor identification dysfunction and assess the relation between odor identification and cognitive performance in the AD spectrum (including SCD, mild cognitive impairment (MCI), and AD).Methods: Patients (84 SCD, 129 MCI, 52 AD) and 35 controls underwent the Sniffin' Sticks Screen 16 test and comprehensive neuropsychological examination.Results: Odor identification scores were progressively lower moving from normal older adult to SCD, MCI, and AD. Additionally,the proportion of odor identification dysfunction were increasingly higher in the AD spectrum (p for trend <0.001), but no significant difference was found in the proportion of subjective olfactory dysfunction. No significant correlation was found between odor identification and cognition in the normal older adults and SCD subjects, but odor identification correlated with global cognition in the MCI (r = 0.199, p = 0.033) and in the AD (r = 0.300, p = 0.036) patients. Multiple linear regression showed that odor identification dysfunction was most strongly associated with memory among different cognitive subdomains and was most strongly associated with immediate verbal recall among different memory subdomains.Conclusion: Odor identification dysfunction is already present with SCD and deepens with disease severity in the AD spectrum, and it may contribute to predicting cognitive decline and identifying SCD subjects who are at risk of developing AD. [ABSTRACT FROM AUTHOR]

Background: Patients with spirochetal infection, which causes neurosyphilis (NS) and at a later stage general paresis of the insane (GPI), present with brain pathology features of Alzheimer's disease (AD). However, the relationships among these illnesses regarding biomarker levels are still unclear.Objective: To explore biomarker levels in NS and GPI compared with those in AD and the relationship between biomarker levels and cognitive function in NS and GPI.Methods: Levels of neurogranin (NGRN) and β-amyloid precursor protein cleaving enzyme (BACE1) in cerebrospinal fluid (CSF)/plasma, together with amyloid-β 1-40 (Aβ40), Aβ42, and total tau in the CSF of 23 AD patients, 55 GPI patients, and 13 NS patients were measured. Patients were classified into none-to-mild, moderate, and severe stages of cognitive impairment.Results: Levels of CSF NGRN, BACE1, and tau as well as plasma BACE1 levels were significantly different among groups. In the none-to-mild stage, plasma BACE1 levels correlated with the protein levels in CSF and were significantly increased in AD patients versus GPI patients. The CSF tau levels in AD patients were significantly increased versus GPI patients in the moderate and severe stages. Pooling data from GPI and NS patients, both CSF tau and plasma NGRN levels correlated with cognitive scale scores.Conclusion: GPI and NS patients might have different biomarker level patterns compared to AD patients. While plasma BACE1 could be a promising early biomarker for distinguishing AD from GPI, CSF tau and plasma NGRN levels might be valuable in indications of cognitive function in pooled NS populations. [ABSTRACT FROM AUTHOR]

Background: Our previous study in animal models revealed that bilirubin could induce Aβ formation and deposition. Bilirubin may be important in neurodegenerative dementia with Aβ deposition. Hence, lowering the concentration of the free bilirubin capable of crossing the blood brain–barrier may benefit the treatment of Alzheimer's disease (AD). Objectives: The objectives of this study were to examine the change in the serum bilirubin and albumin concentrations of dementia patients with Aβ deposition, and to determine the effects of intravenous administration of albumin in the treatment of AD. Methods: Bilirubin and albumin concentrations in dementia patients with Aβ deposition were examined. Cell viability and apoptosis were determined in dopaminergic neuron-like cells MN9D treated with bilirubin in the presence of diverse concentrations of serum. Human albumin at a dose of 10 g every 2 weeks for 24 weeks was administered intravenously to AD patients to examine the effect of albumin on AD symptoms. Results: Significantly higher indirect bilirubin (IBIL) concentrations, lower albumin concentrations, and higher ratio of IBIL to albumin (IBIL/ALB) were observed in dementia patients with Aβ deposition, including AD, dementia with Lewy bodies, and general paresis of insane. In vitro assays showed that bilirubin-induced injury in cultured dopaminergic neuron-like cells negatively depends on the concentration of serum in the culture medium. General linear model with repeated measures analysis indicated a main effect of group on the change in albumin concentrations and Alzheimer's Disease Cooperative Study Activities of Daily Living Inventory scale (ADCS-ADL) scores, and the main effect of time and group, and group-by-time interaction on the change of Clinical Dementia Rating Scale–Sum of Boxes (CDR-SB) scores. Analysis of the combined data of the entire 28 weeks of assessment period using the area under curve convincingly showed significantly improvements in the change of albumin concentrations, ADCS-ADL scores, and CDR-SB scores. Conclusion: IBIL and the IBIL/ALB ratio are significantly higher in dementia patients with Aβ deposition, and intravenous administration of albumin is beneficial to AD treatment. Trial Registration: The intervention study was registered at http://www.chictr.org.cn (ChiCTR-IOR-17011539). Date of registration: June 1, 2017. [ABSTRACT FROM AUTHOR]

Background: The pattern of neuropsychiatric features of patients with neurosyphilis and the impact of the severity of cognitive impairment on neuropsychiatric syndromes are unknown. Objective: We aim to assess the neuropsychiatric features of patients with neurosyphilis, and compare the impact of the severity of cognitive impairment on the neuropsychiatric syndromes between neurosyphilis and Alzheimer disease (AD). Methods: Neuropsychiatric symptoms and the degree of cognitive impairment were assessed in a case-control study of 91 neurosyphilis, 162 AD, 157 mild cognitive impairment, and 139 normal controls by the Neuropsychiatric Inventory (NPI) scale and Clinical Dementia Rating scale, respectively. Factor analysis was performed on the 12 NPI items. Results: Factor analysis showed that patients with neurosyphilis showed more severe neuropsychiatric syndromes at the dementia stage than those neurosyphilis patients at the mild cognitive impairment stage, while neuropsychiatric manifestations were equally common among the different stages of dementia (all p < 0.05). Frontal lobe syndrome was more severe in patients with neurosyphilis than in patients with AD from the early mild cognitive impairment stage to the moderate dementia stage (all p < 0.01). Conclusions: Patients with neurosyphilis show different patterns of neuropsychiatric syndromes at the mild cognitive impairment and dementia stages, and differ from patients with AD. [ABSTRACT FROM AUTHOR]

FDG-PET and SPECT studies suggest that hypometabolism and hypoperfusion in occipital lobe and posterior cingulate gyrus (PCG) are prominent features of dementia with Lewy bodies (DLB) and Alzheimer's disease (AD), respectively. Cerebral blood flow and glucose metabolism are tightly linked to brain energy metabolism. 1H-MRS is a useful tool to directly detect energy metabolism. We aimed to use 1H-MRS to characterize metabolite concentrations in the occipital lobe and PCG in DLB and AD patients, and estimate their usefulness in the diagnosis of DLB. Nineteen DLB, 21 AD, and 18 normal control (NC) subjects underwent 1H-MRS with the voxels placed in bilateral occipital lobes and left PCG. The N-acetylaspartate (NAA) and glutamate (Glu) concentrations in occipital lobe in DLB were lower than those in AD and NC. Concentrations of these two metabolites in PCG in DLB were lower than those in NC, and were the same as those in AD. These results remained robust after correcting for relative gray matter volume in the region of interest. The NAA and Glu concentrations in occipital lobe in DLB were found correlated with global cognitive function. From the ROC curves with Glu concentrations in occipital lobe, the mean areas under the curve were 0.845 for the DLB/control (with sensitivity 83.3% and specificity 84.2%) and 0.773 for the DLB/AD (with sensitivity 66.7% and specificity 84.2%). Our study suggests that 1H-MRS investigation is valuable to detect the characteristic patterns of metabolite concentrations and is helpful in the diagnostic process and assessing dementia severity in DLB. [ABSTRACT FROM AUTHOR]

The overlapping clinical features of Alzheimer's disease ( AD) and Dementia with Lewy bodies ( DLB) make differentiation difficult in the clinical environment. Evaluating the CSF levels of biomarkers in AD and DLB patients could facilitate clinical diagnosis. CSF Visinin-like protein-1 ( VILIP-1), a calcium-mediated neuronal injury biomarker, has been described as a novel biomarker for AD. The aim of this study was to investigate the diagnostic utility of CSF VILIP-1 and VILIP-1/Aβ1-42 ratio to distinguish AD from DLB. Levels of CSF VILIP-1, t-tau, p-tau181P, Aβ1-42, and α-synuclein were measured in 61 AD patients, 32 DLB patients, and 40 normal controls using commercial ELISA kits. The results showed that the CSF VILIP-1 level had significantly increased in AD patients compared with both normal controls and DLB patients. The CSF VILIP-1 and VILIP-1/Aβ1-42 levels had enough diagnostic accuracy to allow the detection and differential diagnosis of AD. Additionally, CSF VILIP-1 levels were positively correlated with t-tau and p-tau181P within each group and with α-synuclein in the AD and control groups. We conclude that CSF VILIP-1 could be a diagnostic marker for AD, differentiating it from DLB. The analysis of biomarkers, representing different neuropathologies, is an important approach reflecting the heterogeneous features of AD and DLB. [ABSTRACT FROM AUTHOR]

Background: Odor identification (OI) impairment increases the risk of Alzheimer's disease and brain abnormalities in patients with late-life depression (LLD). However, it remains unclear whether abnormal functional connectivity (FC) of olfactory regions is involved in the relationship between OI impairment and dementia risk in LLD patients. The current study aims to explore the olfactory FC patterns of LLD patients and how olfactory FCs mediate the relationship between OI and cognition.Methods: A total of 150 participants underwent resting-state functional magnetic resonance imaging and psychometric and olfactory assessments. The primary and secondary olfactory regions were selected as regions of interest to investigate olfactory FC patterns and their association with OI and cognitive performance in LLD patients.Results: Compared with LLD patients without OI impairment and normal controls, LLD patients with OI impairment exhibited increased FC between the left orbital frontal cortex (OFC) and left calcarine gyrus, between the left OFC and right lingual gyrus, between the right OFC and right rectus gyrus, and decreased FC between the right piriform cortex and right superior parietal lobule. Additionally, these abnormal FCs were associated with scores of OI, global cognition and language function. Finally, the FC between the right piriform cortex and right superior parietal lobule exhibited a partially mediated effect on the relationship between OI and MMSE scores.Limitations: The present study did not exclude the possible effect of drugs.Conclusion: LLD patients with OI impairment exhibited more disrupted olfactory FC (a decrease in the primary olfactory cortex and an increase in the secondary olfactory cortex) than LLD patients with intact OI, and these abnormal FCs may serve as potential targets for neuromodulation in LLD patients to prevent them from developing dementia. [ABSTRACT FROM AUTHOR]

Highlights • The profound shifts of TRP metabolism and KYN metabolism were found in LLD with MD patients. • No KP changes were found in the LLD without MD patients. • Language ability was associated with the presence of depression, with or without MD. Abstract Kynurenine pathway (KP) activation is associated with many neuropsychiatric diseases, such as major depressive disorder (MDD) and Alzheimer's disease (AD). Investigations conducted on MDD seldom shed light on KP changes in late-life depression (LLD), though memory deficit (MD) in patients with LLD is a predictable sign of AD. Thus, we aimed to investigate whether tryptophan (TRP) metabolism and kynurenine (KYN) metabolism were imbalanced in patients with LLD with MD and in patients with LLD without MD. We explored KP characteristics between LLD with MD and LLD without MD groups. We investigated 85 patients with LLD and MD, 71 patients with LLD without MD, and 129 healthy controls (HCs). Serum concentrations of TRP, KYN, and kynurenic acid (KYNA) were detected by liquid chromatography-tandem mass spectrometry. Cognition performance was assessed by the Mini-Mental State Examination (MMSE). Language ability was assessed by the Boston Naming Test (BNT). Depressive symptoms were assessed by the 17-item Hamilton Depression Scale (HAMD-17). Lower TRP and KYNA levels, a lower KYNA/KYN ratio and a higher KYN/TRP ratio were found in patients with LLD and MD compared to those in HC. Low levels of TRP and KYN, in the absence of a changed KYN/TRP ratio, were found in patients with LLD without MD. The KYNA/TRP ratio and MMSE, BNT, and HAMD-17 scores were associated with the presence of LLD. MMSE scores and a trend for the KYN/TRP ratio were associated with the presence of MD in patients with LLD. Aside from MMSE scores, there was a trend toward an association between the KYN/TRP ratio and the presence of MD in patients with LLD. In conclusion, profound shifts in TRP metabolism and KYN metabolism were found in patients with LLD and MD but not in patients with LLD without MD. [ABSTRACT FROM AUTHOR]

Although swallowing exercises are a fundamental treatment for dysphagia, few studies have evaluated the effectiveness of swallowing training in patients with Alzheimer's disease. We recruited 93 patients with Alzheimer's disease from three hospitals in Guangdong, China. This was a parallel armed randomized controlled trial that randomly assigned patients to intervention (n = 48) and control (n = 45) groups. The intervention group adopted systematic stepwise swallowing training for four weeks based on routine dysphagia care. The control group implemented routine dysphagia care, including diet and posture management and health education about swallowing dysfunction. The swallowing function was the primary outcome, which was assessed using the Water Swallowing Test and Standard Swallowing Assessment. An abnormal eating behavior questionnaire was used to assess the incidence of aberrant eating behavior in patients with Alzheimer's disease. The Mini-Nutritional Assessment Short Form and Barthel index were adopted to evaluate the nutritional status and ability to carry out daily activities between groups. SPSS software was used to perform the chi-square test, t -test, and generalized estimation equation for data analysis. We analyzed the effects of the stepwise swallowing training program using the generalized estimating equation method. The intervention group exhibited greater improvements in their swallowing function (Water Swallowing Test: β = − 3.133, 95 % CI: − 4.113, − 2.154, P < 0.001; Standard Swallowing Assessment: β = − 5.813, 95 % CI: − 7.782, − 3.844, P < 0.001), abnormal eating behaviors (abnormal eating behavior questionnaire: β = − 13.324, 95 % CI: − 21.643, − 5.005, P = 0.002), daily function (Barthel index: β = 11.280, 95 % CI: 4.021, 18.540, P = 0.002), and nutritional status (Mini-Nutritional Assessment Short Form: β = 2.402, 95 % CI: 1.313, 3.490, P < 0.001) over time than the routine-care group in the fourth week. Stepwise swallowing training is a safe and effective intervention for managing dysphagia and other related symptoms in patients with Alzheimer's disease. [ABSTRACT FROM AUTHOR]