Journal of Alzheimer's Disease - Volume 93, issue 4

Authors: Yang, Fuxia | Yang, Lu | Fang, Xuhao | Deng, Yao | Mao, Renling | Yan, Aijuan | Wei, Wenshi

Article Type: Research Article

Abstract: Background: Neurodegenerative disease pathology is associated with neuroinflammation, but evidence on idiopathic normal pressure hydrocephalus (iNPH) remains limited and cerebrospinal fluid (CSF) biomarker profiles need to be elucidated. Objective: To investigate whether iNPH pathological mechanisms are associated with greater CSF markers of core Alzheimer’s disease pathology (amyloid-β42 (Aβ42 ), phosphorylated tau (P-tau)), neurodegeneration (total tau (T-tau)), and neuroinflammation (soluble triggering receptor expressed on myeloid cells 2 (sTREM2), chitinase-3-like protein 1 (YKL-40)). Methods: The study analyzed lumbar CSF samples from 63 patients with iNPH and 20 age-matched orthopedic surgery patients who had no preoperative gait or cognitive …impairment (control group). Aβ42 , T-tau, P-tau, sTREM2, and YKL-40 in different subgroups were investigated. Results: CSF sTREM2 levels were significantly higher in the iNPH group than in the control group, but no significant between-group difference was noted in YKL-40. Moreover, YKL-40 levels were significantly higher in the tap test non-responders than in the tap test responders (p  = 0.021). At the 1-year follow-up after shunt surgery, the CSF P-tau levels were significantly lower (p  = 0.020) in those with gait improvement and the CSF sTREM2 levels were significantly lower (p  = 0.041) in those with cognitive improvement. In subgroup analysis, CSF sTREM2 levels were strongly correlated with CSF YKL-40 in the iNPH group (r  = 0.443, p  < 0.001), especially in the tap test non-responders (r  = 0.653, p  = 0.002). Conclusion: YKL-40 and sTREM2 are disease-specific markers of neuroinflammation, showing higher CSF levels in iNPH. In addition, sTREM2 is positively associated with YKL-40, indicating that interactions of glial cells play an important role in iNPH pathogenesis. Show more

Keywords: Biomarkers, cerebrospinal fluid, neuroinflammation, normal pressure hydrocephalus

DOI: 10.3233/JAD-221180

Citation: Journal of Alzheimer's Disease, vol. 93, no. 4, pp. 1341-1354, 2023

Authors: Xu, Shan | Ren, Yifei | Liu, Rui | Li, Yuanjing | Hou, Tingting | Wang, Yongxiang | Wang, Xiang | Wang, Lidan | Monastero, Roberto | Du, Yifeng | Cong, Lin | Qiu, Chengxuan

Article Type: Research Article

Abstract: Background: Few community-based studies have examined occurrence and progression of subjective cognitive decline (SCD). Objective: To investigate prevalence and progression of SCD among rural-dwelling Chinese elderly people. Methods: This cohort study included 2,488 cognitively unimpaired adults (age≥65 years) who were examined at baseline (2014-2015) and followed in 2018. Demographic, epidemiological, clinical, and neuropsychological data were collected via in-person interviews and clinical examinations following a structured questionnaire. At baseline, SCD was assessed using the self-rated Ascertain Dementia 8-item Questionnaire. At follow-up, Alzheimer’s disease (AD) and vascular dementia (VaD) were clinically diagnosed following the international criteria. Data were …analyzed using logistic regression models. Results: The prevalence of SCD was 40.07%. SCD at baseline was associated with the multivariable-adjusted odds ratio (OR) of 1.51 (95% confidence interval 1.10–2.07) for incident cognitive impairment, no dementia (CIND) and 3.11 (1.64–5.93) for incident AD. Among people with SCD at baseline, the multivariable-adjusted OR of incident CIND was 0.55(0.32–0.96) for hyperlipidemia; the multivariable-adjusted OR of incident AD was 1.21 (1.14–1.30) for older age, 0.32 (0.12–0.88) for high education, 2.60 (1.11–6.08) for carrying APOE ɛ 4 allele, and 0.34 (0.13–0.86) for high social support, whereas the multivariable-adjusted OR of incident VaD was 6.30 (1.71–23.18) for obesity. Conclusion: SCD affects over 40% of rural-dwelling cognitively unimpaired older adults in China. SCD is associated with accelerated progression to CIND and AD. Older age, lack of school education, APOE ɛ 4 allele, and low social support are associated with an increased risk of progression from SCD to AD, whereas obesity is related to accelerated progression to VaD. Show more

Keywords: Alzheimer’s disease, dementia, population-based study, prevalence, risk factors, subjective cognitive decline

DOI: 10.3233/JAD-221280

Citation: Journal of Alzheimer's Disease, vol. 93, no. 4, pp. 1355-1368, 2023

Authors: Chu, Min | Jiang, Deming | Liu, Li | Nie, Binbin | Cui, Bo | Wang, Yihao | Rosa-Neto, Pedro | Wu, Liyong

Article Type: Research Article

Abstract: Background: The insula is the predominant brain region impaired in behavioral variant frontotemporal dementia (bvFTD). However, structural and functional changes in the sub-insula in the asymptomatic stage of bvFTD are unknown. Objective: To describe structural and functional changes in insula subregions in asymptomatic carriers of the P301L mutation of the microtubule-associated protein tau (MAPT ) gene and patients with bvFTD. Methods: Six asymptomatic MAPT P301L mutation carriers and 12 MAPT negative control subjects of the same pedigree were enrolled, along with 30 patients with a clinical diagnosis of bvFTD and 30 matched controls. All …subjects underwent hybrid positron emission tomography/magnetic resonance imaging. Atlas-based parcellation using a fine-grained Brainnetome Atlas was conducted to assess gray matter (GM) volume, metabolism, and metabolic connectivity in the sub-insula (region of interest). Results: There was no significant GM atrophy or hypometabolism in insula subregions in asymptomatic MAPT P301L carriers, although decreased metabolic connectivity between vIa-middle temporal gyrus, vIa-temporal poles, dIa-middle temporal gyrus and dIa-temporal poles; and increased connectivity between vIa-orbitofrontal, vIa-dorsal lateral superior frontal gyrus, and dIa-orbitofrontal and dIa-dorsal lateral superior frontal gyrus were observed. Patients with bvFTD had significant atrophy and hypometabolism in all insula subregions and decreased metabolic connectivity in the whole brain, including vIa/dIa-middle temporal and vIa/dIa-temporal poles. The standardized uptake value ratios of vIa and dIa were negatively associated with Frontal behavior inventory disinhibition scale scores. Conclusion: Metabolic connectivity is altered in vIa and dIa subregions of the sub-insula in MAPT P301L mutation carriers before the occurrence of atrophy, hypometabolism, and clinical symptoms. Show more

Keywords: Behavioral variant frontotemporal dementia, 18F-FDG-PET, insula, microtubule-associated protein tau, network

DOI: 10.3233/JAD-221035

Citation: Journal of Alzheimer's Disease, vol. 93, no. 4, pp. 1369-1380, 2023

Authors: Nallapu, Bhargav T. | Petersen, Kellen K. | Lipton, Richard B. | Grober, Ellen | Sperling, Reisa A. | Ezzati, Ali

Article Type: Research Article

Abstract: Background: Alcohol use disorders have been categorized as a ‘strongly modifiable’ risk factor for dementia. Objective: To investigate the cross-sectional association between alcohol consumption and cognition in older adults and if it is different across sexes or depends on amyloid-β (Aβ) accumulation in the brain. Methods: Cognitively unimpaired older adults (N = 4387) with objective and subjective cognitive assessments and amyloid positron emission tomography (PET) imaging were classified into four categories based on their average daily alcohol use. Multivariable linear regression was then used to test the main effects and interactions with sex and Aβ levels. …Results: Individuals who reported no alcohol consumption had lower scores on the Preclinical Alzheimer Cognitive Composite (PACC) compared to those consuming one or two drinks/day. In sex-stratified analysis, the association between alcohol consumption and cognition was more prominent in females. Female participants who consumed two drinks/day had better performance on PACC and Cognitive Function Index (CFI) than those who reported no alcohol consumption. In an Aβ-stratified sample, the association between alcohol consumption and cognition was present only in the Aβ– subgroup. The interaction between Aβ status and alcohol consumption on cognition was not significant. Conclusion: Low or moderate consumption of alcohol was associated with better objective cognitive performance and better subjective report of daily functioning in cognitively unimpaired individuals. The association was present only in Aβ– individuals, suggesting that the pathophysiologic mechanism underlying the effect of alcohol on cognition is independent of Aβ pathology. Further investigation is required with larger samples consuming three or more drinks/day. Show more

Keywords: Alcohol, Alzheimer’s disease, amyloid PET, cognition, sex differences

DOI: 10.3233/JAD-221079

Citation: Journal of Alzheimer's Disease, vol. 93, no. 4, pp. 1381-1393, 2023

Authors: Lin, Huamei | Pan, Tingting | Wang, Min | Ge, Jingjie | Lu, Jiaying | Ju, Zizhao | Chen, Keliang | Zhang, Huiwei | Guan, Yihui | Zhao, Qianhua | Shan, Baoci | Nie, Binbin | Zuo, Chuantao | Wu, Ping

Article Type: Research Article

Abstract: Background: Metabolic asymmetry has been observed in Alzheimer’s disease (AD), but different studies have inconsistent viewpoints. Objective: To analyze the asymmetry of cerebral glucose metabolism in AD and investigate its clinical significance and potential metabolic network abnormalities. Methods: Standardized uptake value ratios (SUVRs) were obtained from 18 F-FDG positron emission tomography (PET) images of all participants, and the asymmetry indices (AIs) were calculated according to the SUVRs. AD group was divided into left/right-dominant or bilateral symmetric hypometabolism (AD-L/AD-R or AD-BI) when more than half of the AIs of the 20 regions of interest (ROIs) were < …–2SD, >2SD, or between±1SD. Differences in clinical features among the three AD groups were compared, and the abnormal network characteristics underlying metabolic asymmetry were explored. Results: In AD group, the proportions of AD-L, AD-R, and AD-BI were 28.4%, 17.9%, and 18.5%, respectively. AD-L/AD-R groups had younger age of onset and faster rate of cognitive decline than AD-BI group (p  < 0.05). The absolute values of AIs in half of the 20 ROIs became higher at follow-up than at baseline (p  < 0.05). Compared with those in AD-BI group, metabolic connection strength of network, global efficiency, cluster coefficient, degree centrality and local efficiency were lower, but shortest path length was longer in AD-L and AD-R groups (p  < 0.05). Conclusion: Asymmetric and symmetric hypometabolism may represent different clinical subtypes of AD, which may provide a clue for future studies on the heterogeneity of AD and help to optimize the design of clinical trials. Show more

Keywords: Alzheimer’s disease, cerebral glucose hypometabolism, graph theory, metabolic asymmetry, metabolic connectivity, Mini-Mental State Examination

DOI: 10.3233/JAD-221258

Citation: Journal of Alzheimer's Disease, vol. 93, no. 4, pp. 1395-1406, 2023

Authors: Eikelboom, Willem S. | van den Berg, Esther | Coesmans, Michiel | Goudzwaard, Jeannette A. | Koopmanschap, Marc | Lazaar, Najoua | van Bruchem-Visser, Rozemarijn L. | Driesen, Jan J.M. | den Heijer, Tom | Hoogers, Susanne | de Jong, Frank Jan | Mattace-Raso, Francesco | Thomeer, Elsbeth C. | Vrenken, Suzanne | Vroegindeweij, Lilian J.H.M. | Zuidema, Sytse U. | Singleton, Ellen H. | van Swieten, John C. | Ossenkoppele, Rik | Papma, Janne M.

Article Type: Research Article

Abstract: Background: Neuropsychiatric symptoms (NPS) are highly prevalent in Alzheimer’s disease (AD) and are associated with negative outcomes. However, NPS are currently underrecognized at the memory clinic and non-pharmacological interventions are scarcely implemented. Objective: To evaluate the effectiveness of the Describe, Investigate, Create, Evaluate (DICE) method™ to improve the care for NPS in AD at the memory clinic. Methods: We enrolled sixty community-dwelling people with mild cognitive impairment or AD dementia and NPS across six Dutch memory clinics with their caregivers. The first wave underwent care as usual (n  = 36) and the second wave underwent the DICE …method (n  = 24). Outcomes were quality of life (QoL), caregiver burden, NPS severity, NPS-related distress, competence managing NPS, and psychotropic drug use. Reliable change index was calculated to identify responders to the intervention. A cost-effectiveness analysis was performed and semi-structured interviews with a subsample of the intervention group (n  = 12). Results: The DICE method did not improve any outcomes over time compared to care as usual. Half of the participants of the intervention group (52%) were identified as responders and showed more NPS and NPS-related distress at baseline compared to non-responders. Interviews revealed substantial heterogeneity among participants regarding NPS-related distress, caregiver burden, and availability of social support. The intervention did not lead to significant gains in quality-adjusted life years and well-being years nor clear savings in health care and societal costs. Conclusion: The DICE method showed no benefits at group-level, but individuals with high levels of NPS and NPS-related distress may benefit from this intervention. Show more

Keywords: Alzheimer’s disease, apathy, behavioral and psychological symptoms of dementia, delivery of care, dementia, depression, neuropsychiatric inventory, neuropsychiatric symptoms

DOI: 10.3233/JAD-230116

Citation: Journal of Alzheimer's Disease, vol. 93, no. 4, pp. 1407-1423, 2023

Authors: Best, Merci N. | Lim, Yunu | Ferenc, Nina N. | Kim, Nayoung | Min, Lia | Wang, Dora Bigler | Sharifi, Kamyar | Wasserman, Anna E. | McTavish, Sloane A. | Siller, Karsten H. | Jones, Marieke K. | Jenkins, Paul M. | Mandell, James W. | Bloom, George S.

Article Type: Research Article

Abstract: Background: In Alzheimer’s disease (AD) brain, neuronal polarity and synaptic connectivity are compromised. A key structure for regulating polarity and functions of neurons is the axon initial segment (AIS), which segregates somatodendritic from axonal proteins and initiates action potentials. Toxic tau species, including extracellular oligomers (xcTauOs), spread tau pathology from neuron to neuron by a prion-like process, but few other cell biological effects of xcTauOs have been described. Objective: Test the hypothesis that AIS structure is sensitive to xcTauOs. Methods: Cultured wild type (WT) and tau knockout (KO) mouse cortical neurons were exposed to xcTauOs, and …quantitative western blotting and immunofluorescence microscopy with anti-TRIM46 monitored effects on the AIS. The same methods were used to compare TRIM46 and two other resident AIS proteins in human hippocampal tissue obtained from AD and age-matched non-AD donors. Results: Without affecting total TRIM46 levels, xcTauOs reduce the concentration of TRIM46 within the AIS and cause AIS shortening in cultured WT, but not TKO neurons. Lentiviral-driven tau expression in tau KO neurons rescues AIS length sensitivity to xcTauOs. In human AD hippocampus, the overall protein levels of multiple resident AIS proteins are unchanged compared to non-AD brain, but TRIM46 concentration within the AIS and AIS length are reduced in neurons containing neurofibrillary tangles. Conclusion: xcTauOs cause partial AIS damage in cultured neurons by a mechanism dependent on intracellular tau, thereby raising the possibility that the observed AIS reduction in AD neurons in vivo is caused by xcTauOs working in concert with endogenous neuronal tau. Show more

Keywords: Alzheimer’s disease, ankyrin-G protein, axon initial segment, neurofascin protein, TRIM46 protein, tau proteins

DOI: 10.3233/JAD-221284

Citation: Journal of Alzheimer's Disease, vol. 93, no. 4, pp. 1425-1441, 2023

Authors: Yan, Yibing | Wu, Yue | Xiao, Guixian | Wang, Lu | Zhou, Shanshan | Wei, Ling | Tian, Yanghua | Wu, Xingqi | Hu, Panpan | Wang, Kai

Article Type: Research Article

Abstract: Background: Abnormalities in white matter (WM) may be a crucial physiologic feature of Alzheimer’s disease (AD). However, neuroimaging’s ability to visualize the underlying functional degradation of the WM region in AD is unclear. Objective: This study aimed to explore the differences in amplitude of low-frequency fluctuation (ALFF) and fractional ALFF (fALFF) in the WM region of patients with AD and healthy controls (HC) and to investigate further whether these values can provide supplementary information for diagnosing AD. Methods: Forty-eight patients with AD and 46 age-matched HC were enrolled and underwent resting-state functional magnetic resonance imaging and …a neuropsychological battery assessment. We analyzed the differences in WM activity between the two groups and further explored the correlation between WM activity in the different regions and cognitive function in the AD group. Finally, a machine learning algorithm was adopted to construct a classifier in detecting the clinical classification ability of the values of ALFF/ALFF in the WM. Results: Compared with HCs, patients with AD had lower WM activity in the right anterior thalamic radiation, left frontal aslant tract, and left forceps minor, which are all positively related to global cognitive function, memory, and attention function (all p  < 0.05). Based on the combined WM ALFF and fALFF characteristics in the different regions, individuals not previously assessed were classified with moderate accuracy (75%), sensitivity (71%), specificity (79%), and area under the receiver operating characteristic curve (85%). Conclusion: Our results suggest that WM activity is reduced in AD and can be used for disease classification. Show more

Keywords: Alzheimer’s disease, amplitude of low-frequency fluctuation, cognitive function, resting-state functional magnetic resonance imaging, white matter

DOI: 10.3233/JAD-221037

Citation: Journal of Alzheimer's Disease, vol. 93, no. 4, pp. 1443-1455, 2023

Authors: Xiang, Qingyan | Andersen, Stacy L. | Sweigart, Benjamin | Gunn, Sophia | Nygaard, Marianne | Perls, Thomas T. | Sebastiani, Paola

Article Type: Research Article

Abstract: Background: Discovering patterns of cognitive domains and characterizing how these patterns associate with other risk factors and biomarkers can improve our understanding of the determinants of cognitive aging. Objective: To discover patterns of cognitive domains using neuropsychological test results in Long Life Family Study (LLFS) and characterize how these patterns associate with aging markers. Methods: 5,086 LLFS participants were administered neuropsychological tests at enrollment. We performed a cluster analysis of six baseline neuropsychological test scores and tested the association between the identified clusters and various clinical variables, biomarkers, and polygenic risk scores using generalized estimating equations …and the Chi-square test. We used Cox regression to correlate the clusters with the hazard of various medical events. We investigated whether the cluster information could enhance the prediction of cognitive decline using Bayesian beta regression. Results: We identified 12 clusters with different cognitive signatures that represent profiles of performance across multiple neuropsychological tests. These signatures significantly correlated with 26 variables including polygenic risk scores, physical and pulmonary functions, and blood biomarkers and were associated with the hazard of mortality (p  < 0.01), cardiovascular disease (p  = 0.03), dementia (p  = 0.01), and skin cancer (p  = 0.03). Conclusion: The identified cognitive signatures capture multiple domains simultaneously and provide a holistic vision of cognitive function, showing that different patterns of cognitive function can coexist in aging individuals. Such patterns can be used for clinical intervention and primary care. Show more

Keywords: Aging, Alzheimer’s disease, cluster analysis, cognition, longevity, neuropsychology, survival

DOI: 10.3233/JAD-221025

Citation: Journal of Alzheimer's Disease, vol. 93, no. 4, pp. 1457-1469, 2023

Authors: van der Heide, Frank C.T. | Mokhtar, Sara | Khanna, Anjani | Said, Mozhda | Henry, Ronald M.A. | Kroon, Abraham A. | Dagnelie, Pieter C. | Eussen, Simone J.P.M. | Berendschot, Tos T.J.M. | Schouten, Jan S.A.G. | Schram, Miranda T. | van der Kallen, Carla J.H. | van Greevenbroek, Marleen M.J. | Wesselius, Anke | Savelberg, Hans H.C.M. | Schaper, Nicolaas C. | Webers, Carroll A.B. | Stehouwer, Coen D.A.

Article Type: Research Article

Abstract: Background: If retinal indices of neurodegeneration are to be biomarkers for the monitoring of cerebral neurodegeneration, it is important to establish whether potentially modifiable risk factors for dementia are associated with retinal neurodegenerative changes. Objective: To study associations of dementia risk factors with retinal sensitivity, an index of retinal neural function, and retinal nerve fiber layer (RNFL) thickness, an index of retinal neural structure. Methods: We used cross-sectional data from The Maastricht Study (up to 5,666 participants, 50.5% men, mean age 59.7), and investigated associations with regression analyses (adjusted for potential confounders). Results: Most …risk factors under study (i.e., hyperglycemia, unhealthy diet, lower cardiorespiratory fitness, smoking, alcohol consumption, and hypertension) were significantly associated with lower retinal sensitivity and lower RNFL thickness. Conclusion: Findings of this population-based study support the concept that retinal neural indices may be biomarkers for the monitoring of therapeutic strategies that aim to prevent early-stage cerebral neurodegeneration and, ultimately, dementia. Show more

Keywords: Alcohol consumption, Alzheimer’s disease, cardiorespiratory fitness, dementia, imaging biomarkers, obesity, optical coherence tomography, perimetry, physical inactivity, retinal neurodegeneration

DOI: 10.3233/JAD-230104

Citation: Journal of Alzheimer's Disease, vol. 93, no. 4, pp. 1471-1483, 2023