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Background: Antibiotics for systemic use may increase the risk of neurodegeneration, yet antibiotic therapy may be able to halt or mitigate an episode of neurodegenerative decline. Objective: To investigate the association of sporadic use of antibiotics and subsequent dementia risk (including Alzheimer's disease). Methods: We used data from the largest public health insurance fund in Germany, the Allgemeine Ortskrankenkasse (AOK). Each of the 35,072 dementia cases aged 60 years and older with a new dementia diagnosis during the observation period from 2006 to 2018 was matched with two control-patients by age, sex, and time since 2006. We ran conditional logistic regression models for dementia risk in terms of odds ratios (OR) as a function of antibiotic use for the entire antibiotic group and for each antibiotic subgroup. We controlled for comorbidities, need for long-term care, hospitalizations, and nursing home placement. Results: Antibiotic use was positively associated with dementia (OR = 1.18, 95% confidence interval (95% CI):1.14–1.22), which became negative after adjustment for comorbidities, at least one diagnosis of bacterial infection or disease, and covariates (OR = 0.93, 95% CI:0.90–0.96). Subgroups of antibiotics were also negatively associated with dementia after controlling for covariates: tetracyclines (OR = 0.94, 95% CI:0.90–0.98), beta-lactam antibacterials, penicillins (OR = 0.93, 95% CI:0.90–0.97), other beta-lactam antibacterials (OR = 0.92, 95% CI:0.88–0.95), macrolides, lincosamides, and streptogramins (OR = 0.88, 95% CI:0.85–0.92), and quinolone antibacterials (OR = 0.96, 95% CI:0.92–0.99). Conclusion: Our results suggest that there was a decreased likelihood of dementia for preceding antibiotic use. The benefits of antibiotics in reducing inflammation and thus the risk of dementia need to be carefully weighed against the increase in antibiotic resistance. [ABSTRACT FROM AUTHOR]

There is growing evidence that promising biomarkers of inflammation in Alzheimer´s disease (AD) and other neurodegenerative diseases correlate strongest to levels of tau or neurofilament, indicating an inflammatory response to neuronal damage or death. To test this hypothesis, we investigated three AD candidate markers (ferritin, fatty acid binding protein 3 (FABP‐3), and neurogranin) in interrelation to established AD and inflammatory protein markers. We further aimed to determine if such interrelations would be evident in pathological subjects only or also under non‐pathological circumstances. Cerebrospinal fluid levels of the three proteins were quantified in samples from the University Clinic of Bonn (UKB) Department of Neurodegenerative Diseases & Geriatric Psychiatry, Germany. Data were analyzed based on clinical or biomarker‐defined stratification of subjects with adjustment for covariates age, sex, and APOE status. Levels of ferritin, FABP‐3 and neurogranin were elevated in subjects with pathological levels of t‐tau independent of beta‐amyloid status. The three markers correlated with each other, tau isoforms, age, and those inflammatory markers previously described as related to neurodegeneration, predominantly sTREM2, macrophage migration inhibitory factor, soluble vascular endothelial growth factor receptor, soluble vascular cell adhesion molecule 1 (sVCAM‐1), and C1q. These interrelations existed in subjects with pathological and sub‐pathological tau levels, in particular for FABP‐3 and neurogranin. Relations to ferritin were independent of absolute levels of tau, too, but showed differing trajectories between pathological and non‐pathological subjects. A specific set of inflammatory markers is highly related to markers of neuronal damage such as tau, neurogranin, or FABP‐3. These proteins could be used as readouts of the inflammatory response during the neurodegeneration phase of AD. [ABSTRACT FROM AUTHOR]

Objective: We evaluated the short-, medium-, and long-term effects of sepsis on dementia incidence using German health claims data., Methods: A total of 161,567 patients (65 years or older) were followed from 2004 to 2015 at quarterly intervals. Time since sepsis was categorized into 0 (the effective quarter of sepsis diagnosis), 1-8, and ≥9 quarters since the latest diagnosis of sepsis, taking into account admission to intensive care unit and controlling for delirium, surgery, age, sex, and comorbidities. Incident dementia was defined for all persons who did not have a validated dementia diagnosis in 2004 and 2005 and who received a first-time, valid diagnosis between 2006 and 2015., Results: During the quarter of sepsis diagnosis, patients not admitted to intensive care had a 3.14-fold (95% CI 2.83-3.49) increased risk, and those with intensive care stay had a 2.22-fold (95% CI: 1.83-2.70) increased risk of receiving an incident dementia diagnosis compared with patients without sepsis. The impact of sepsis on incident dementia remained in the following 2 years, remitting only thereafter., Conclusions: For sepsis survivors, medium-term dementia risk remains elevated, whereas long-term risk may reach the level of those without sepsis, even after controlling for delirium. These findings encourage identifying modifiable components of hospital and rehabilitation care., (Copyright © 2020 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Introduction: Previous studies showed associations of brain volume differences and biomarker evidence for Alzheimer's disease (AD) in subjective cognitive decline (SCD). The consistency of this finding across SCD studies has not been investigated., Methods: We studied gray matter volume differences between SCD subjects with and without cerebrospinal fluid biomarker evidence for AD across three European memory clinic samples (German Center for Neurodegenerative Diseases Longitudinal Cognitive Impairment and Dementia study, Amsterdam, Barcelona). Analysis of covariance models with samples and cerebrospinal fluid biomarkers as between-subject factors were calculated., Results: A significant main effect for AD biomarker (Aβ 42 - > Aβ 42 +) in the left medial temporal lobe (MTL) was found, with the absence of main effects for sample or interaction effects between AD biomarker and sample. This indicates consistent lower left MTL volume across three samples in SCD subjects with abnormal Aβ 42 levels., Discussion: Our results support the model that in the presence of AD pathology, SCD corresponds to the late preclinical stage (stage 2 of AD) with smaller MTL volumes., (Copyright © 2018 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.)

Background: Deep phenotyping and longitudinal assessment of predementia at-risk states of Alzheimer's disease (AD) are required to define populations and outcomes for dementia prevention trials. Subjective cognitive decline (SCD) is a pre-mild cognitive impairment (pre-MCI) at-risk state of dementia, which emerges as a highly promising target for AD prevention., Methods: The German Center for Neurodegenerative Diseases (DZNE) is conducting the multicenter DZNE-Longitudinal Cognitive Impairment and Dementia Study (DELCODE), which focuses on the characterization of SCD in patients recruited from memory clinics. In addition, individuals with amnestic MCI, mild Alzheimer's dementia patients, first-degree relatives of patients with Alzheimer's dementia, and cognitively unimpaired control subjects are studied. The total number of subjects to be enrolled is 1000. Participants receive extensive clinical and neuropsychological assessments, magnetic resonance imaging, positron emission tomography, and biomaterial collection is perfomed. In this publication, we report cognitive and clinical data as well as apolipoprotein E (APOE) genotype and cerebrospinal fluid (CSF) biomarker results of the first 394 baseline data sets., Results: In comparison with the control group, patients with SCD showed slightly poorer performance on cognitive and functional measures (Alzheimer's Disease Assessment Scale-cognitive part, Clinical Dementia Rating, Functional Activities Questionnaire), with all mean scores in a range which would be considered unimpaired. APOE4 genotype was enriched in the SCD group in comparison to what would be expected in the population and the frequency was significantly higher in comparison to the control group. CSF Aβ42 was lower in the SCD group in comparison to the control group at a statistical trend with age as a covariate. There were no group differences in Tau or pTau concentrations between the SCD and the control groups. The differences in all measures between the MCI group and the AD group were as expected., Conclusions: The initial baseline data for DELCODE support the approach of using SCD in patients recruited through memory clinics as an enrichment strategy for late-stage preclinical AD. This is indicated by slightly lower performance in a range of measures in SCD in comparison to the control subjects as well as by enriched APOE4 frequency and lower CSF Aβ42 concentration., Trial Registration: German Clinical Trials Register DRKS00007966 . Registered 4 May 2015.

Background: Alterations of intrinsic networks from resting state fMRI (rs-fMRI) have been suggested as functional biomarkers of Alzheimer's disease (AD)., Objective: To determine the diagnostic accuracy of multicenter rs-fMRI for prodromal and preclinical stages of AD., Methods: We determined rs-fMRI functional connectivity based on Pearson's correlation coefficients and amplitude of low-frequency fluctuation in people with subjective cognitive decline, people with mild cognitive impairment, and people with AD dementia compared with healthy controls. We used data of 247 participants of the prospective DELCODE study, a longitudinal multicenter observational study, imposing a unified fMRI acquisition protocol across sites. We determined cross-validated discrimination accuracy based on penalized logistic regression to account for multicollinearity of predictors., Results: Resting state functional connectivity reached significant cross-validated group discrimination only for the comparison of AD dementia cases with healthy controls, but not for the other diagnostic groups. AD dementia cases showed alterations in a large range of intrinsic resting state networks, including the default mode and salience networks, but also executive and language networks. When groups were stratified according to their CSF amyloid status that was available in a subset of cases, diagnostic accuracy was increased for amyloid positive mild cognitive impairment cases compared with amyloid negative controls, but still inferior to the accuracy of hippocampus volume., Conclusion: Even when following a strictly harmonized data acquisition protocol and rigorous scan quality control, widely used connectivity measures of multicenter rs-fMRI do not reach levels of diagnostic accuracy sufficient for a useful biomarker in prodromal stages of AD.