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Behavioral and psychological symptoms of dementia (BPSD) profiles vary depending on etiology in patients with mild-to-moderate BPSD. It is not known if similar differences exist in patients with severe BPSD.We analyzed data collected at baseline in 398 patients with severe BPSD (NPI ≥ 32) and defined diagnosis of dementia (Alzheimer's disease [AD] 297; frontotemporal dementia [FTD] 39; Lewy body disease/Parkinsonian dementia [LBD/PD] 31; and vascular dementia [VD] 31) included in the European multicenter cohort RECAGE.Mean total NPI was 52.11 (18.55). LBD/PD patients demonstrated more hallucinations, more anxiety and more delusions than patients with other dementia. FTD patients had less delusions and more disinhibition than patients with other neurodegenerative disorders. These profiles overlapped partially with those reported in the literature in patients with less severe symptoms.Patients with severe BPSD display different and specific profiles of neuropsychiatric symptoms depending on dementia etiology.

Amyloid positron emission tomography (PET) allows the direct assessment of amyloid deposition, one of the main hallmarks of Alzheimer disease. However, this technique is currently not widely reimbursed because of the lack of appropriately designed studies demonstrating its clinical effect.To assess the clinical effect of amyloid PET in memory clinic patients.The AMYPAD-DPMS is a prospective randomized clinical trial in 8 European memory clinics. Participants were allocated (using a minimization method) to 3 study groups based on the performance of amyloid PET: arm 1, early in the diagnostic workup (within 1 month); arm 2, late in the diagnostic workup (after a mean [SD] 8 [2] months); or arm 3, if and when the managing physician chose. Participants were patients with subjective cognitive decline plus (SCD+; SCD plus clinical features increasing the likelihood of preclinical Alzheimer disease), mild cognitive impairment (MCI), or dementia; they were assessed at baseline and after 3 months. Recruitment took place between April 16, 2018, and October 30, 2020. Data analysis was performed from July 2022 to January 2023.Amyloid PET.The main outcome was the difference between arm 1 and arm 2 in the proportion of participants receiving an etiological diagnosis with a very high confidence (ie, ≥90% on a 50%-100% visual numeric scale) after 3 months.A total of 844 participants were screened, and 840 were enrolled (291 in arm 1, 271 in arm 2, 278 in arm 3). Baseline and 3-month visit data were available for 272 participants in arm 1 and 260 in arm 2 (median [IQR] age: 71 [65-77] and 71 [65-77] years; 150/272 male [55%] and 135/260 male [52%]; 122/272 female [45%] and 125/260 female [48%]; median [IQR] education: 12 [10-15] and 13 [10-16] years, respectively). After 3 months, 109 of 272 participants (40%) in arm 1 had a diagnosis with very high confidence vs 30 of 260 (11%) in arm 2 (P < .001). This was consistent across cognitive stages (SCD+: 25/84 [30%] vs 5/78 [6%]; P < .001; MCI: 45/108 [42%] vs 9/102 [9%]; P < .001; dementia: 39/80 [49%] vs 16/80 [20%]; P < .001).In this study, early amyloid PET allowed memory clinic patients to receive an etiological diagnosis with very high confidence after only 3 months compared with patients who had not undergone amyloid PET. These findings support the implementation of amyloid PET early in the diagnostic workup of memory clinic patients.EudraCT Number: 2017-002527-21.

Speech impairments are an early feature of Alzheimer's disease (AD) and consequently, analysing speech performance is a promising new digital biomarker for AD screening. Future clinical AD trials on disease modifying drugs will require a shift to very early identification of individuals at risk of dementia. Hence, digital markers of language and speech may offer a method for screening of at-risk populations that are at the earliest stages of AD, eventually in combination with advanced machine learning. To this end, we developed a screening battery consisting of speech-based neurocognitive tests. The automated test performs a remote primary screening using a simple telephone.PROSPECT-AD aims to validate speech biomarkers for identification of individuals with early signs of AD and monitor their longitudinal course through access to well-phenotyped cohorts.PROSPECT-AD leverages ongoing cohorts such as EPAD (UK), DESCRIBE and DELCODE (Germany), and BioFINDER Primary Care (Sweden) and Beta-AARC (Spain) by adding a collection of speech data over the telephone to existing longitudinal follow-ups. Participants at risk of dementia are recruited from existing parent cohorts across Europe to form an AD 'probability-spectrum', i.e., individuals with a low risk to high risk of developing AD dementia. The characterization of cognition, biomarker and risk factor (genetic and environmental) status of each research participants over time combined with audio recordings of speech samples will provide a well-phenotyped population for comparing novel speech markers with current gold standard biomarkers and cognitive scores.N= 1000 participants aged 50 or older will be included in total, with a clinical dementia rating scale (CDR) score of 0 or 0.5. The study protocol is planned to run according to sites between 12 and 18 months.The speech protocol includes the following neurocognitive tests which will be administered remotely: Word List [Memory Function], Verbal Fluency [Executive Functions] and spontaneous free speech [Psychological and/ or behavioral symptoms]. Speech features on the linguistic and paralinguistic level will be extracted from the recordings and compared to data from CSF and blood biomarkers, neuroimaging, neuropsychological evaluations, genetic profiles, and family history. Primary candidate marker from speech will be a combination of most significant features in comparison to biomarkers as reference measure. Machine learning and computational techniques will be employed to identify the most significant speech biomarkers that could represent an early indicator of AD pathology. Furthermore, based on the analysis of speech performances, models will be trained to predict cognitive decline and disease progression across the AD continuum.The outcome of PROSPECT-AD may support AD drug development research as well as primary or tertiary prevention of dementia by providing a validated tool using a remote approach for identifying individuals at risk of dementia and monitoring individuals over time, either in a screening context or in clinical trials.

Speech comprehension in noisy environments depends on central auditory functions, which are vulnerable in Alzheimer's disease (AD). Binaural processing exploits two ear sounds to optimally process degraded sound information; its characteristics are poorly understood in AD. We studied behavioral and electrophysiological alterations in binaural processing among 121 participants (AD = 27; amnestic mild cognitive impairment [aMCI] = 33; subjective cognitive decline [SCD] = 30; cognitively normal [CN] = 31). We observed impairment of binaural processing in AD and aMCI, and detected a U-shaped curve change in phase synchrony (declining from CN to SCD and to aMCI, but increasing from aMCI to AD). This improvement in phase synchrony accompanying more severe cognitive stages could reflect neural adaptation for binaural processing. Moreover, increased phase synchrony is associated with worse memory during the stages when neural adaptation apparently occurs. These findings support a hypothesis that neural adaptation for binaural processing deficit may exacerbate cognitive impairment, which could help identify biomarkers and therapeutic targets in AD.

Background: Depressive symptoms often co-occur with Alzheimer’s disease (AD) and can impact neuropsychological test results. In early stages of AD, disentangling cognitive impairments due to depression from those due to neurodegeneration often poses a challenge. Objective: We aimed to identify neuropsychological tests able to detect AD-typical pathology while taking into account varying degrees of depressive symptoms. Methods: A battery of neuropsychological tests (CERAD-NP) and the Geriatric Depression Scale (GDS) were assessed, and cerebrospinal fluid (CSF) biomarkers were obtained. After stratifying patients into CSF positive or negative and into low, moderate, or high GDS score groups, sensitivity and specificity and area under the curve (AUC) were calculated for each subtest. Results: 497 participants were included in the analyses. In patients with low GDS scores (≤10), the highest AUC (0.72) was achieved by Mini-Mental State Examination, followed by Constructional Praxis Recall and Wordlist Total Recall (AUC = 0.714, both). In patients with moderate (11–20) and high (≥21) GDS scores, Trail Making Test-B (TMT-B) revealed the highest AUCs with 0.77 and 0.82, respectively. Conclusion: Neuropsychological tests showing AD-typical pathology in participants with low GDS scores are in-line with previous results. In patients with higher GDS scores, TMT-B showed the best discrimination. This indicates the need to focus on executive function rather than on memory task results in depressed patients to explore a risk for AD.

Objectives To assess the acceptability and validity of the 3 levels of the EQ-5D (EQ-5D-3L) compared with the Quality of Life in Alzheimer’s Diseases (QoL-AD) in patients living with dementia. Methods The analysis was based on 560 dyads of persons with dementia and their caregivers of the multicenter observational study of dementia care networks in Germany (DemNet-D). Health-related quality of life was assessed by face-to-face interviews using the EQ-5D-3L (self-rating) and the QoL-AD (self- and proxy-rating). The number of missing values, the score ranges (observed vs possible range) and the floor and ceiling effects were used to assess the acceptability. We used one-way analyses of variance and multivariate linear regression models to evaluate the discriminative ability. The convergent validity was assessed using Spearman's correlation coefficient (rs) and multivariate regression models. Results The EQ-5D index had a higher response rate (89% vs 84%) and a comparable floor (>1%) but a higher ceiling effect (18% vs >1%) compared with the QoL-AD. Both measures can significantly differentiate between different stages of general health, instrumental activities of daily living, and depression. The EQ-5D index and the visual analog scale self-rating scores strongly correlated with the QoL-AD self-rating (rs = 0.644 and 0.553, respectively) but not with the proxy-rating score (rs = 0.314 and rs = 0.170, respectively), which was confirmed by multivariate regression analyses. Conclusion The results satisfy acceptability, discriminative ability, and convergent validity for moderately cognitively and functionally impaired patients living with dementia. The EQ-5D-3L performed comparably with the QoL-AD, and could, therefore, be used in economic evaluations in dementia. The differences between self- and proxy-ratings should be evaluated and considered in the interpretation of health-related quality of life scores.

Alzheimer’s disease (AD) diagnosis is based on psychological and imaging tests but can also include monitoring cerebrospinal fluid (CSF) biomarkers. However, CSF based-neurochemical approaches are expensive and invasive, limiting their use to well-equipped settings. In contrast, blood-based biomarkers are minimally invasive, cost-effective, and a widely accessible alternative. Blood-derived exosomes have recently emerged as a reliable AD biomarker source, carrying disease-specific cargo. Fourier-transformed infrared (FTIR) spectroscopy meets the criteria for an ideal diagnostic methodology since it is rapid, easy to implement, and has high reproducibility. This metabolome-based technique is useful for diagnosing a broad range of diseases, although to our knowledge, no reports for FTIR spectroscopy applied to exosomes in AD exist. In this ground-breaking pilot study, FTIR spectra of serum and serum-derived exosomes from two independent cohorts were acquired and analyzed using multivariate analysis. The regional UA-cohort includes 9 individuals, clinically diagnosed with AD, mean age of 78.7 years old; and the UMG-cohort comprises 12 individuals, clinically diagnosed with AD (based on molecular and/or imaging data), mean age of 73.2 years old. Unsupervised principal component analysis of FTIR spectra of serum-derived exosomes revealed higher discriminatory value for AD cases when compared to serum as a whole. Consistently, the partial least-squares analysis revealed that serum-derived exosomes present higher correlations than serum. In addition, the second derivative peak area calculation also revealed significant differences among Controls and AD cases. The results obtained suggest that this methodology can discriminate cases from Controls and thus be potential useful to assist in AD clinical diagnosis.

Objective We aimed to investigate factors associated with self- and carer-rated quality of life (QoL) and caregiver burden related to very mild to severe clinical Alzheimer disease (AD). Methods One hundred patient-carer dyads were recruited, and assessments of relevant outcomes were performed, including sociodemographic characteristics, QoL, activities of daily living (ADL), cognitive performance, behavioural and psychological symptoms of dementia (BPSD), caregiver burden, and health resource utilisation. Results There was a strong correlation between carer- and self-rated QoL, with patients consistently rating their QoL higher than caregivers. Duration of illness did not affect the QoL ratings. There was an inverse association between both self- and carer-rated QoL with age, age at symptom onset, impairment of ADL, time spent on assisting the patient, and depression. Both self- and carer-rated QoL ratings were higher if the caregiver was a spouse vs a child. Carer-rated QoL was inversely associated with severity of dementia, BPSD, caregiver burden, and requirement to supervise the patient. The variables age at symptom onset, ADL, and living together with the primary caregiver explained 34.50% of the variance in self-rated QoL, whereas age at symptom onset, ADL, and BPSD explained 48.20% of the variance in carer-rated QoL. For caregiver burden, 26% of the variance was explained by the variables ADL, living together with the primary caregiver, and agitation. Conclusion Our study highlights the need for a stronger focus on QoL in clinical AD research by providing further pieces of evidence on the key determinants, including the important aspect of caregiver burden.

The early detection of cognitive impairment or dementia is in the focus of current research as the amount of cognitively impaired individuals will rise intensely in the next decades due to aging population worldwide. Currently available diagnostic tools to detect mild cognitive impairment (MCI) or dementia are time-consuming, invasive or expensive and not suitable for wide application as required by the high number of people at risk. Thus, a fast, simple and sensitive test is urgently needed to enable an accurate detection of people with cognitive dysfunction and dementia in the earlier stages to initiate specific diagnostic and therapeutic interventions. We examined digital Clock Drawing Test (dCDT) kinematics for their clinical utility in differentiating patients with amnestic MCI (aMCI) or mild Alzheimer’s dementia (mAD) from healthy controls (HCs) and compared it with the diagnostic value of the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) neuropsychological battery total score. Data of 381 participants (138 patients with aMCI, 106 patients with mAD and 137 HCs) was analyzed in the present study. All participants performed the clock drawing test (CDT) on a tablet computer and underwent the CERAD test battery and depression screening. CERAD total scores were calculated by subtest summation, excluding MMSE scores. All tablet variables (i.e. time in air, time on surface, total time, velocity, pressure, pressure/velocity relation, strokes per minute, time not painting, pen-up stroke length, pen-up/pen-down relation, and CDT score) during dCDT performance were entered in a forward stepwise logistic regression model to assess, which parameters best discriminated between aMCI or mAD and HC. Receiver operating characteristics (ROC) curves were constructed to visualize the specificity in relation to the sensitivity of dCDT variables against CERAD total scores in categorizing the diagnostic groups. dCDT variables provided a slightly better diagnostic accuracy of 81.5% for discrimination of aMCI from HCs than using CERAD total score (accuracy 77.5%). In aMCI patients with normal CDT scores, both dCDT (accuracy 78.0%) and CERAD total scores (accuracy 76.0%) were equally accurate in discriminating against HCs. Finally, in differentiating patients with mAD from healthy individuals, accuracy of both dCDT (93.0%) and CERAD total scores (92.3%) was excellent. Our findings suggest that dCDT is a suitable screening tool to identify early cognitive dysfunction. Its performance is comparable with the time-consuming established psychometric measure (CERAD test battery).

Tau deposition begins in the medial temporal lobe (MTL) in aging and Alzheimer's disease (AD), and MTL neural dysfunction is commonly observed in these groups. However, the association between tau and MTL neural activity has not been fully characterized. We investigated the effects of tau on repetition suppression, the reduction of activity for repeated stimulus presentations compared to novel stimuli. We used task-based functional MRI (fMRI) to assess MTL subregional activity in 21 young adults (YA) and 45 cognitively normal human older adults (OA; total sample: 37 females, 29 males). AD pathology was measured with position emission tomography (PET), using18F-Flortaucipir for tau and11C-Pittsburgh compound B (PiB) for amyloid-β (Aβ). The MTL was segmented into six subregions using high-resolution structural images. We compared the effects of low tau pathology, restricted to entorhinal cortex and hippocampus (Tau– OA), to high tau pathology, also occurring in temporal and limbic regions (Tau+ OA). Low levels of tau (Tau– OA vs YA) were associated with reduced repetition suppression activity specifically in anterolateral entorhinal cortex (alEC) and hippocampus, the first regions to accumulate tau. High tau pathology (Tau+ vs Tau– OA) was associated with widespread reductions in repetition suppression across MTL. Further analyses indicated that reduced repetition suppression was driven by hyperactivity to repeated stimuli, rather than decreased activity to novel stimuli. Increased activation was associated with entorhinal tau, but not Aβ. These findings reveal a link between tau deposition and neural dysfunction in MTL, in which tau-related hyperactivity prevents deactivation to repeated stimuli, leading to reduced repetition suppression.SIGNIFICANCE STATEMENTAbnormal neural activity occurs in the medial temporal lobe (MTL) in aging and Alzheimer's disease (AD). Because tau pathology first deposits in the MTL in aging, this altered activity may be due to local tau pathology, and distinct MTL subregions may be differentially vulnerable. We demonstrate that in older adults (OAs) with low tau pathology, there are focal alterations in activity in MTL subregions that first develop tau pathology, while OAs with high tau pathology have aberrant activity throughout MTL. Tau was associated with hyperactivity to repeated stimulus presentations, leading to reduced repetition suppression, the discrimination between novel and repeated stimuli. Our data suggest that tau deposition is related to abnormal activity in MTL before the onset of cognitive decline.

Background: Cognitive functions and activities of daily living (ADL) become increasingly impaired with progressing Alzheimer's disease. However, the temporal dynamics of this decline are inconsistent. Objective: To gain insight into the classical temporal cascade of specific cognitive and ADL changes, which may aid in improving detection of an impending clinical deterioration in patients, and to select ADL items and tests most sensitive to change in a specific disease stage. Methods: Patients with mild Alzheimer's dementia (AD; MMSE = 23.9±2.88) were followed at 12 and 24 months. Lead-lag analysis of changes in cognitive and functional outcome measures (CDR-SOB, 12 neuropsychological subtest scores from the CERAD + test battery, 25 Bayer-ADL items) was applied to rank the temporal sequence of changes on an ordinal scale. Results: Of 164 patients with mild AD, moderate disease progression was identified in 84 patients over 24 months (ΔMMSE 5.8±8.64; ΔCDR-SOB 4.32±4.03). Ten Bayer-ADL item measures were altered early in moderate progressors and included in a new ADL composite score. Accordingly, the new ADL score surpassed all neuropsychological measures in repeated lead-lag analysis. The Bayer-ADL total score, TMT-A, and MMSE were lagging variables in all lead-lag analyses. Conclusion: Short-term clinical deterioration in mild AD is initially preceded by changes (i.e., decline) in a well-defined set of ADL and not in classical cognitive measures. Keywords: Alzheimer’s disease; bayer activities of daily living scale; cognitive changes; disease progression; functional changes; lead and lag analysis.

International audience; Cognitive reserve is present in Alzheimer's disease (AD) seniors with high education attainment making them clinically resilient to extended brain neuropathology and neurodegeneration. Here, we tested whether subjective memory complaint (SMC) seniors with AD neuropathology and high education attainment of the prospective INSIGHT-preAD cohort (Paris) may present abnormal eyesclosed resting state posterior electroencephalographic rhythms around individual alpha frequency peak, typically altered in AD patients. The SMC participants negative to amyloid PET AD markers (SMCneg) with high (over low-moderate) education level showed higher posterior alpha 2 power density (possibly "neuro-protective"). Furthermore, amyloid PET-positive SMC (SMCpos) participants with high (over low-moderate) education level showed higher temporal alpha 3 power density (possibly "neuro-protective") and lower posterior alpha 2 power density (possibly "compensatory"). This effect may reflect cognitive reserve as no differences in brain graywhite matter, and cognitive functions were observed between these SMCpos/SMCneg subgroups. Preclinical Alzheimer's neuropathology may interact with education attainment and neurophysiological mechanisms generating cortical alpha rhythms around individual alpha frequency peak (i.e., alpha 2 and 3) in quiet wakefulness.

TREM2 was suggested to be an important regulator of microglia during neurodegeneration, but previous studies report conflicting results in relation to soluble TREM2 (sTREM2) in cerebrospinal fluid (CSF) when using clinical criteria to classify Alzheimer's disease (AD). The present study explores sTREM2 CSF levels and their associations with other biomarkers and cognitive measures in a prospective AD cohort. Based on the available CSF biomarker information, 497 subjects were classified according to the 2018 National Institute on Aging-Alzheimer's Association research framework guidelines, which group biomarkers into those of amyloid-β deposition, tau pathology, and neurodegeneration. CSF sTREM2 concentrations were associated with markers of neurodegeneration and fibrillar tau pathology, but not amyloidosis; sTREM2 concentrations were increased in total tau-positive versus -negative individuals; sTREM2 was not related to cognitive and other biomarker changes over time; and sTREM2 concentrations increased over time in total tau-positive versus -negative individuals with AD pathophysiology. The present study provides evidence in support of sTREM2 in CSF as a marker of neuroinflammation across the spectrum of early clinical AD. sTREM2 is linked to neuronal injury and may therefore offer complementary information relevant for diagnostic purposes and novel treatment approaches targeting the immune system in AD.

OBJECTIVE Subjective cognitive decline (SCD), the earliest symptom in preclinical Alzheimer's disease (AD), is insufficient to identify individuals at risk for AD dementia. Therefore, we aimed to investigate whether function in instrumental activities of daily living (IADL) contributes to identification. METHODS We analysed data of cognitively unimpaired participants of the prospective German Study on Ageing, Cognition, and Dementia in Primary Care Patients (AgeCoDe) and its extension, the Study on Needs, Health Service Use, Costs and Health-related Quality of Life in a Large Sample of Oldest-old Primary Care Patients (AgeQualiDe), collected over 10.5 years. Development of AD dementia was quantified as incidence rates (IRs) per 1000 person-years. Cox regression was used to assess the association of SCD and IADL function in regard to incident AD dementia. RESULTS Of 1467 included individuals, 792 (54.0%) reported SCD at baseline. Impaired IADL were present in 50 (3.4%) individuals. IR for AD dementia was highest in individuals with SCD and impaired IADL (49.7; 95% CI, 24.8-99.3). Unadjusted and adjusted Cox analyses revealed an increased AD dementia risk for individuals with SCD and impaired IADL (uHR = 6.1; 95% CI, 2.9-13.0; P

Background Accurate assessment of health-related quality of life as an endpoint in intervention studies is a major challenge in dementia research. The DEMQOL (29 items) and the proxy version (32 items), which is partly based on the DEMQOL, are internationally used instruments. To date, there is no information on the structural validity, item distribution, or internal consistency for the German language version of these questionnaires. Methods This psychometric study is based on a secondary data analysis of a sample of 201 outpatients with a mild form of Alzheimer’s disease (AD) and their informal caregivers. The informal caregivers who were interviewed were involved in the care of the person with AD several times per week. The analysis for the evaluation of the structural validity was performed using Mokken scale analysis. The internal consistency was calculated using the ρ of the Molenaar Sijtsma statistic and Cronbach’s α. Results For both versions, four subscales were identified: [A] “positive emotions”, [B] “negative emotions”, [C] “physical and cognitive functioning”, and [D] “daily activities and social relationships”. For both instruments, the internal consistency of all subscales was considered “good” (ρ = 0.71–0.88, α = 0.72–0.87). Conclusions The results are a first indication of good construct validity of the instruments used for the German setting. We recommend further investigations of the test-retest reliability and the inter-rater reliability of the proxy instrument. Electronic supplementary material The online version of this article (10.1186/s12877-018-0930-0) contains supplementary material, which is available to authorized users.

Introduction Little is known about effects of physical activity (PA) in genetically driven early-onset autosomal dominant Alzheimer's disease (AD). Methods A total of 372 individuals participating at the Dominantly Inherited Alzheimer Network study were examined to evaluate the cross-sectional relationship of PA with cognitive performance, functional status, cognitive decline, and AD biomarkers in cerebrospinal fluid. Mutation carriers were categorized as high or low exercisers according to WHO recommendations. Results Mutation carriers with high PA showed significantly better cognitive and functional performance and significantly less AD-like pathology in cerebrospinal fluid than individuals with low PA. Mutation carriers with high PA scored 3.4 points better on Mini Mental State Examination at expected symptom onset and fulfilled the diagnosis of very mild dementia 15.1 years later compared with low exercisers. Discussion These results support a beneficial effect of PA on cognition and AD pathology even in individuals with genetically driven autosomal dominant AD.

Background: Alzheimer's disease (AD) is a heterogeneous disorder. Objective: To investigate whether cognitive AD subtypes are associated with different rates of disease progression. Methods: We included 1,066 probable AD patients from the Amsterdam Dementia Cohort (n = 290), Alzheimer's Disease Neuroimaging Initiative (n = 268), Dementia Competence Network (n = 226), and University of California, San Francisco (n = 282) with available follow-up data. Patients were previously clustered into two subtypes based on their neuropsychological test results: one with most prominent memory impairment (n = 663) and one with most prominent non-memory impairment (n = 403). We examined associations between cognitive subtype and disease progression, as measured with repeated Mini-Mental State Examination (MMSE) and Clinical Dementia Rating scale sum of boxes (CDR sob), using linear mixed models. Furthermore, we investigated mortality risk associated with subtypes using Cox proportional hazard analyses. Results: Patients were 71±9 years old; 541 (51%) were female. At baseline, pooled non-memory patients had worse MMSE scores (23.1±0.1) and slightly worse CDR sob (4.4±0.1) than memory patients (MMSE 24.0±0.1; p < 0.001; CDR sob 4.1±0.1; p < 0.001). During follow-up, pooled non-memory patients showed steeper annual decline in MMSE (-2.8±0.1) and steeper annual increase in CDR sob (1.8±0.1) than memory patients (MMSE - 1.9±0.1; p interaction

Funder: Startup Funds for Leading Talents at Beijing Normal University, Individuals with mild cognitive impairment (MCI) of different subtypes show distinct alterations in network patterns. The first aim of this study is to identify the subtypes of MCI by employing a regional radiomics similarity network (R2SN). The second aim is to characterize the abnormality patterns associated with the clinical manifestations of each subtype. An individual-level R2SN is constructed for N = 605 normal controls (NCs), N = 766 MCI patients, and N = 283 Alzheimer's disease (AD) patients. MCI patients' R2SN profiles are clustered into two subtypes using nonnegative matrix factorization. The patterns of brain alterations, gene expression, and the risk of cognitive decline in each subtype are evaluated. MCI patients are clustered into "similar to the pattern of NCs" (N-CI, N = 252) and "similar to the pattern of AD" (A-CI, N = 514) subgroups. Significant differences are observed between the subtypes with respect to the following: 1) clinical measures; 2) multimodal neuroimaging; 3) the proportion of progression to dementia (61.54% for A-CI and 21.77% for N-CI) within three years; 4) enriched genes for potassium-ion transport and synaptic transmission. Stratification into the two subtypes provides new insight for risk assessment and precise early intervention for MCI patients.

Contains fulltext : 229556.pdf (Publisher’s version ) (Closed access) Various biomarkers are available to support the diagnosis of neurodegenerative diseases in clinical and research settings. Among the molecular imaging biomarkers, amyloid-PET, which assesses brain amyloid deposition, and (18)F-fluorodeoxyglucose ((18)F-FDG) PET, which assesses glucose metabolism, provide valuable and complementary information. However, uncertainty remains regarding the optimal timepoint, combination, and an order in which these PET biomarkers should be used in diagnostic evaluations because conclusive evidence is missing. Following an expert panel discussion, we reached an agreement on the specific use of the individual biomarkers, based on available evidence and clinical expertise. We propose a diagnostic algorithm with optimal timepoints for these PET biomarkers, also taking into account evidence from other biomarkers, for early and differential diagnosis of neurodegenerative diseases that can lead to dementia. We propose three main diagnostic pathways with distinct biomarker sequences, in which amyloid-PET and (18)F-FDG-PET are placed at different positions in the order of diagnostic evaluations, depending on clinical presentation. We hope that this algorithm can support diagnostic decision making in specialist clinical settings with access to these biomarkers and might stimulate further research towards optimal diagnostic strategies.

Objective: Cognitive reserve influences age of onset, speed of progression, and clinical manifestations of Alzheimer’s disease. We investigated whether cognitive reserve interacts with clinical and neuropsychological parameters in mild cognitive impairment (MCI). Methods: In this cross-sectional study, we recruited 273 people (70.6 ± 10.1 years, 54.6% women) suffering from subjective memory complaints ( n = 65), MCI ( n = 121), or dementia ( n = 87). Patients underwent neuropsychological evaluation, laboratory testing, and brain imaging. Additionally, we obtained information on years of education and help-seeking motivation. Results: MCI patients with a university degree were significantly older than those without (71.6 ± 9.6 vs. 66.9 ± 10.3, p = 0.02). University-educated MCI patients demonstrated superior performance in verbal fluency. Intrinsic help-seeking motivation (self-referral) was associated with higher cognitive reserve. Female MCI patients presented with greater intrinsic motivation. Conclusion: Cognitive reserve modulates clinical and neuropsychological measures in patients with MCI.

Surface dyslexia, a diagnostic feature of the semantic variant of primary progressive aphasia (svPPA), is difficult to observe in many languages. It can be conceptualized as one manifestation of a more general “regularization” effect—that is, with semantic impairment, patients fail to recognize exceptions and revert to default rules. Objective: We predicted that, analogous to surface dyslexia in English, German patients with svPPA would regularize irregular verbs, especially those of lower frequency and in the less frequently used preterite tense. Method: Regularization was investigated in German through past-tense verb inflectional morphology in N = 10 svPPA, N = 5 PPA related to Alzheimer pathology (Aß+PPA), N = 5 patients with nonfluent variant PPA (nfvPPA), N = 12 typical (amnestic presentation) Alzheimer’s disease (AD), and N = 32 healthy controls. The task involved perfect- and preterite-tense inflection of regular and irregular verbs of high and low frequency. Results: Errors in svPPA particularly involved regularization (e.g., I swim → I swimmed, I have swimmed), whereas Aß+PPA made a wide range of other errors (e.g., verb agreement or tense errors). Regularization was rare in AD and controls, whereas the expected frequency effects (low worse than high) were found in svPPA. nfvPPA had profound difficulties in inflecting verbs in general. Conclusion: The study illustrates how tests tailored to a specific language can reveal the regularization effect of svPPA. For more universal diagnostic recommendations, future revisions for svPPA should consider substituting the criterion of surface dyslexia for that of a general criterion of regularization of language rules, the former being an example of the latter. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Contains fulltext : 220327.pdf (Publisher’s version ) (Closed access) The present study explores the associations of soluble TREM2, an important regulator of microglial activity linked to Alzheimer's disease (AD), with other known inflammatory proteins in cerebrospinal fluid (CSF). We studied 303 participants, including 89 controls, 135 mild cognitive impairment, and 79 AD dementia patients. Using established CSF biomarkers, subjects were classified according to the National Institute on Aging-Alzheimer's Association research framework, which groups markers into those of amyloid-beta deposition (A), tau pathology (T), and neurodegeneration (N). TNFR1, TNFR2, TGF-beta 1, TGF beta 2, IL-9, TNF-alpha, ICAM1, and VCAM1 showed significant concentration differences between the ATN groups, with higher concentrations in more advanced disease categories. sTREM2 was positively associated with the pro-inflammatory proteins TNF-a, TNFR1, TNFR2, ICAM1, VCAM1, and IP-10 and negatively with IL-21; also, positive associations with the anti-inflammatory proteins TGF beta 1, IL-10, and IL-9 were found. Pathway enrichment analysis highlighted the involvement of sTREM2 in key functional clusters including immunoglobulin and cytokine production and cellular response to lipopolysaccharides, cytokines, and steroid hormones. Our work provides further evidence in support of TREM2 as amarker of neuroinflammatory response in AD. 12 p.

The tau protein aggregates in aging and Alzheimer disease and may lead to memory loss through disruption of medial temporal lobe (MTL)-dependent memory systems. Here, we investigated tau-mediated mechanisms of hippocampal dysfunction that underlie the expression of episodic memory decline using fMRI measures of hippocampal local coherence (regional homogeneity; ReHo), distant functional connectivity and tau-PET. We show that age and tau pathology are related to higher hippocampal ReHo. Functional disconnection between the hippocampus and other components of the MTL memory system, particularly an anterior-temporal network specialized for object memory, is also associated with higher hippocampal ReHo and greater tau burden in anterior-temporal regions. These associations are not observed in the posteromedial network, specialized for context/spatial information. Higher hippocampal ReHo predicts worse memory performance. These findings suggest that tau pathology plays a role in disconnecting the hippocampus from specific MTL memory systems leading to increased local coherence and memory decline., Deposition of tau protein aggregates occurs during aging and Alzheimer disease. Here, the authors show that tau burden in the anterior-temporal memory network is associated with disrupted fMRI connectivity and functional isolation of the hippocampus from other memory network components.

Alterations in DNA methylation have been associated with cognitive decline and Alzheimer's disease. A recent study of mild cognitive impairment (MCI) reported a significant association between annual decline in cognitive function and the rs11887120 SNP located in DNMT3A, a gene implicated in DNA methylation. Here, we aimed to replicate this finding in two independent MCI cohorts (n = 1024); however, no significant association was observed in either cohort or the pooled dataset. In stratified analyses for conversion to Alzheimer's disease status, no association between rs11887120 and cognitive decline was observed in either converters or nonconverters. In conclusion, our analyses provide no support for the hypothesis that genetic variants in DNMT3A are implicated in cognitive performance decline in individuals with MCI.

Introduction Subjective cognitive decline (SCD) in cognitively unimpaired older individuals has been recognized as an early clinical at-risk state for Alzheimer’s disease (AD) dementia and as a target population for future dementia prevention trials. Currently, however, SCD is heterogeneously defined across studies, potentially leading to variations in the prevalence of AD pathology. Here, we compared the prevalence and identified common determinants of abnormal AD biomarkers in SCD across three European memory clinics participating in the European initiative on harmonization of SCD in preclinical AD (Euro-SCD). Methods We included three memory clinic SCD samples with available cerebrospinal fluid (CSF) biomaterial (IDIBAPS, Barcelona, Spain, n = 44; Amsterdam Dementia Cohort (ADC), The Netherlands, n = 50; DELCODE multicenter study, Germany, n = 42). CSF biomarkers (amyloid beta (Aβ)42, tau, and phosphorylated tau (ptau181)) were centrally analyzed in Amsterdam using prespecified cutoffs to define prevalence of pathological biomarker concentrations. We used logistic regression analysis in the combined sample across the three centers to investigate center effects with regard to likelihood of biomarker abnormality while taking potential common predictors (e.g., age, sex, apolipoprotein E (APOE) status, subtle cognitive deficits, depressive symptoms) into account. Results The prevalence of abnormal Aβ42, but not tau or ptau181, levels was different across centers (64% DELCODE, 57% IDIBAPS, 22% ADC; p

Background: The CHARIOT PRO Main study is a prospective, non-interventional study evaluating cognitive trajectories in participants at the preclinical stage of Alzheimer’s disease (AD) classified by risk levels for developing mild cognitive impairment due to AD (MCI-AD). Objectives: The study aimed to characterize factors and markers influencing cognitive and functional progression among individuals at-risk for developing MCI-AD, and examine data for more precise predictors of cognitive change, particularly in relation to APOE ε4 subgroup. Design: This single-site study was conducted at the Imperial College London (ICL) in the United Kingdom. Participants 60 to 85 years of age were classified as high, medium (amnestic or non-amnestic) or low risk for developing MCI-AD based on RBANS z-scores. A series of clinical outcome assessments (COAs) on factors influencing baseline cognitive changes were collected in each of the instrument categories of cognition, lifestyle exposure, mood, and sleep. Data collection was planned to occur every 6 months for 48 months, however the median follow-up time was 18.1 months due to early termination of study by the sponsor. Results: 987 participants were screened, among them 690 participants were actively followed-up post baseline, of whom 165 (23.9%) were APOE ε4 carriers; with at least one copy of the allele. The mean age was 68.73 years, 94.6% were white, 57.4% were female, and 34.8% had a Family History of Dementia with a somewhat larger percentage in the APOE ε4 carrier group (42.4%) compared to the non-carrier group (32.4%). Over half of the participants were married and 53% had a Bachelor’s or higher degree. Most frequently, safety events typical for this population consisted of upper respiratory tract infection (10.4%), falls (5.2%), hypertension (3.5%) and back pain (3.0%). Conclusion (clinical relevance): AD-related measures collected during the CHARIOT PRO Main study will allow identification and evaluation of AD risk factors and markers associated with cognitive performance from the pre-clinical stage. Evaluating the psycho-biological characteristics of these pre-symptomatic individuals in relation to their natural neurocognitive trajectories will enhance current understanding on determinants of the initial signs of cognitive changes linked to AD.

Background: Evidence whether single &ldquo, cognitive health&rdquo, foods could prevent cognitive decline is limited. We investigated whether dietary intake of red wine, white wine, coffee, green tea, olive oil, fresh fish, fruits and vegetables, red meat and sausages, assessed by a single-food-questionnaire, would be associated with either incident Alzheimer&rsquo, s dementia (AD) or verbal memory decline. Methods: Participants aged 75+ of the German Study on Aging, Cognition and Dementia in Primary Care Patients (AgeCoDe) cohort were regularly followed over 10 years (n = 2622, n = 418 incident AD cases). Multivariable-adjusted joint modeling of repeated-measures and survival analysis was used, taking gender and Apolipoprotein E4 (APOE &epsilon, 4) genotype into account as possible effect modifiers. Results: Only higher red wine intake was associated with a lower incidence of AD (HR = 0.92, P = 0.045). Interestingly, this was true only for men (HR = 0.82, P &lt, 0.001), while in women higher red wine intake was associated with a higher incidence of AD (HR = 1.15, P = 0.044), and higher white wine intake with a more pronounced memory decline over time (HR = &minus, 0.13, P = 0.052). Conclusion: We found no evidence for these single foods to be protective against cognitive decline, with the exception of red wine, which reduced the risk for AD only in men. Women could be more susceptible to detrimental effects of alcohol.

Current approaches to the early detection of Alzheimer's disease (AD) rely upon classifying individuals as “positive” or “negative” for biomarkers related to the core pathology of β-amyloid (Aβ). However, the accumulation of Aβ begins slowly, years before biomarkers become abnormal. We used longitudinal [11C] Pittsburgh Compound B PET scanning and neuropsychological assessment to investigate the earliest changes in AD pathology and how it affects memory in cognitively normal older humans (N= 71; mean age 75 years; 35% male). We used [18F] AV-1451 PET scanning at the end of the observation period to measure subsequent tau deposition in a subset of our sample (N= 37). We found evidence for an inverted-U relationship between baseline Aβ levels and Aβ slope in asymptomatic older adults, suggesting a slowing of Aβ accumulation even in cognitively normal adults. In participants who were nominally amyloid negative, both the rate of amyloid accumulation and the baseline levels of Aβ predicted early tau deposition in cortical Braak regions associated with AD. Amyloid measures were only sensitive to memory decline as baseline levels of Aβ increased, suggesting that pathological accumulation occurs before impacting memory. These findings support the necessity of early intervention with amyloid-lowering therapies even in those who are amyloid negative.SIGNIFICANCE STATEMENTThe progressive nature of Alzheimer's disease (AD) necessitates the earliest possible detection of pathological or cognitive change if disease progression is to be slowed. We examined cognitively normal older adults in whom AD pathology is starting to develop, with the goal of early detection of AD pathology or cognitive changes. We found amyloid measures to be sensitive early on in predicting subsequent early tau deposition. Further, it appears that rates of amyloid accumulation already begin to slow in preclinical AD, suggesting that it is a relatively late stage of AD progression. Thus, it is crucial to examine older adults early, before amyloid levels have saturated, to intervene to slow disease progression.

Introduction Cognitive change in people at risk of Alzheimer's disease (AD) such as subjective memory complainers is highly variable across individuals. Methods We used latent class growth modeling to identify distinct classes of nonlinear trajectories of cognitive change over 2 years follow-up from 265 subjective memory complainers individuals (age 70 years and older) of the INSIGHT-preAD cohort. We determined the effect of cortical amyloid load, hippocampus and basal forebrain volumes, and education on the cognitive trajectory classes. Results Latent class growth modeling identified distinct nonlinear cognitive trajectories. Education was associated with higher performing trajectories, whereas global amyloid load and basal forebrain atrophy were associated with lower performing trajectories. Discussion Distinct classes of cognitive trajectories were associated with risk and protective factors of AD. These associations support the notion that the identified cognitive trajectories reflect different risk for AD that may be useful for selecting high-risk individuals for intervention trials.

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 The Quality of Life in Alzheimer’s disease scale (QoL-AD) is a widely used Health Related Quality of Life (HRQoL) instrument. However, studies investigating the instrument’s inter-rater reliability (IRR) are missing. This study aimed to determine the item distribution and IRR of the German proxy version of the QoL-AD (13 Items) and a nursing home-specific instrument version (QoL-AD NH, 15 Items). Methods The instruments were applied to 73 people with dementia living in eight nursing homes in Germany. Individuals with dementia were assessed two times by blinded proxy raters. The IRR analyses were based on methodological criteria of the quality appraisal tool for studies of diagnostic reliability (QAREL), the COSMIN group and the single-measure Intra-Class Correlation Coefficient (ICC) for absolute agreement ≥0.70. Results All items for both instrument versions demonstrated acceptable item difficulty, with the exception of one item (QoL-AD proxy). The IRR was moderate for the QoL-AD (ICC: 0.65) and insufficient for the QoL-AD NH (ICC: 0.18). The additional computation of the average measure ICC for two proxy-raters demonstrated a strong IRR (ICC: 0.79) for the QoL-AD and a weak IRR for the QoL-AD NH (ICC: 0.31). The detailed analysis of the IRR for each item underpinned the need for the further development of both instruments. Conclusions The unsatisfactory IRRs for both instruments highlight the need for the development of a user guide including general instructions for instrument application as well as definitions and examples reflecting item meaning. Priority should be given to the development of reliable proxy-person versions of both instruments. Trial registration ClinicalTrials.gov: NCT02295462, Date of registration: 11–20-2014.

Contains fulltext : 190311.pdf (Publisher’s version ) (Closed access) Importance: Cerebral amyloid-beta aggregation is an early event in Alzheimer disease (AD). Understanding the association between amyloid aggregation and cognitive manifestation in persons without dementia is important for a better understanding of the course of AD and for the design of prevention trials. Objective: To investigate whether amyloid-beta aggregation is associated with cognitive functioning in persons without dementia. Design, Setting, and Participants: This cross-sectional study included 2908 participants with normal cognition and 4133 with mild cognitive impairment (MCI) from 53 studies in the multicenter Amyloid Biomarker Study. Normal cognition was defined as having no cognitive concerns for which medical help was sought and scores within the normal range on cognitive tests. Mild cognitive impairment was diagnosed according to published criteria. Study inclusion began in 2013 and is ongoing. Data analysis was performed in January 2017. Main Outcomes and Measures: Global cognitive performance as assessed by the Mini-Mental State Examination (MMSE) and episodic memory performance as assessed by a verbal word learning test. Amyloid aggregation was measured with positron emission tomography or cerebrospinal fluid biomarkers and dichotomized as negative (normal) or positive (abnormal) according to study-specific cutoffs. Generalized estimating equations were used to examine the association between amyloid aggregation and low cognitive scores (MMSE score

Objective: To test whether, in individuals with mild cognitive impairment (MCI), different measures of subjective cognitive decline (SCD) in the memory domain predict abnormal CSF biomarkers of Alzheimer disease (AD). Methods: We analyzed the multicenter baseline (cross-sectional) data of 245 patients with MCI. SCD was measured quantitatively with the Subjective Memory Decline Scale (SMDS) and qualitatively by assessing particular concerns associated with self-experienced worsening of memory. Logistic regression models were used to examine associations between SCD and abnormal CSF biomarkers, taking into account objective memory impairment, depressive symptoms, and education as covariates. Results: Abnormal CSF β-amyloid 1–42 (Aβ42) and more depressive symptoms were associated with higher SMDS scores and with the report of memory concerns. Risk of abnormal CSF Aβ42 increased by an estimated 57% for a 1-SD increase in SMDS scores and was doubled in patients who had SMDS scores >4 or who reported memory concerns, respectively. In addition, both SCD measures predicted risk of having a biomarker signature indicative of prodromal AD defined as presence of low CSF Aβ42 together with either high CSF tau or CSF phosphorylated tau 181 levels. Conclusions: In MCI, specific aspects of SCD severity and quality are related to CSF biomarkers indicative of AD. This extends findings in pre-MCI samples and calls for an improved operational assessment of SCD in MCI. This might be useful for sample enrichment strategies for increased likelihood of AD pathology.

Several studies have indicated that the cannabinoid receptor 2 (CB2) plays an important role in neuroinflammation associated with Alzheimer's disease (AD) progression. The present study examined the role of CB2 in microglia activation in vitro as well as characterizing the neuroinflammatory process in a transgenic mouse model of AD (APP/PS1 mice). We demonstrate that microglia harvested from CB2(-/-) mice were less responsive to pro-inflammatory stimuli than CB2(+/+) microglia, based on the cell surface expression of ICAM and CD40 and the release of chemokines and cytokines CCL2, IL-6, and TNFα. Transgenic APP/PS1 mice lacking CB2 showed reduced percentages of microglia and infiltrating macrophages. Furthermore, they showed lowered expression levels of pro-inflammatory chemokines and cytokines in the brain, as well as diminished concentrations of soluble Aβ 40/42. The reduction in neuroinflammation did not affect spatial learning and memory in APP/PS1*CB2(-/-) mice. These data suggest a role for the CB2 in Alzheimer's disease-associated neuroinflammation, independent of influencing Aβ-mediated pathology and cognitive impairment.

ObjectiveTo assess the onset, sequence, and rate of progression of comprehensive biomarker and clinical measures across the spectrum of Alzheimer disease (AD) using the Dominantly Inherited Alzheimer Network (DIAN) study and compare these to cross-sectional estimates.MethodsWe conducted longitudinal clinical, cognitive, CSF, and neuroimaging assessments (mean of 2.7 [±1.1] visits) in 217 DIAN participants. Linear mixed effects models were used to assess changes in each measure relative to individuals' estimated years to symptom onset and to compare mutation carriers and noncarriers.ResultsLongitudinal β-amyloid measures changed first (starting 25 years before estimated symptom onset), followed by declines in measures of cortical metabolism (approximately 7–10 years later), then cognition and hippocampal atrophy (approximately 20 years later). There were significant differences in the estimates of CSF p-tau181 and tau, with elevations from cross-sectional estimates preceding longitudinal estimates by over 10 years; further, longitudinal estimates identified a significant decline in CSF p-tau181 near symptom onset as opposed to continued elevations.ConclusionThese longitudinal estimates clarify the sequence and temporal dynamics of presymptomatic pathologic changes in autosomal dominant AD, information critical to a better understanding of the disease. The pattern of biomarker changes identified here also suggests that once β-amyloidosis begins, additional pathologies may begin to develop less than 10 years later, but more than 15 years before symptom onset, an important consideration for interventions meant to alter the disease course.

Cognitive reserve (CR) is defined as the ability to maintain functionality despite accumulating pathology. Education has been used as a proxy for CR. For example, by using positron emission tomography imaging, higher educated Alzheimer's disease (AD) patients presented increased amyloid β pathology than lower educated patients despite equal symptomatology. Whether similar associations exist for in vivo tau pathology remains elusive. We utilized [18F]AV-1451 positron emission tomography imaging to examine whether high-educated AD patients (n = 12) present more severe tau pathology compared with low-educated patients (n = 12) despite equal clinical severity in regions of interest corresponding to the pathologic disease stages defined by Braak & Braak. We report tau pathology in advanced Braak stages associated with parietal and frontal regions in high-educated AD patients, whereas in low-educated AD patients tau accumulation is still confined to lower Braak stages associated with temporal and cingulate regions. Highly educated AD patients seem to be able to tolerate more tau tangle pathology than lower educated patients with comparable cognitive impairment supporting the cognitive reserve hypothesis.

Background Genome-wide association studies have established 11 genes for late-onset Alzheimer's disease (AD). We investigated whether these genes jointly affect cognition in a nondemented population and improve prediction of AD. Methods In 5171 nondemented people (age 45–99 years) from the population-based Rotterdam Study, we genotyped APOE -e4 and single nucleotide polymorphisms from the genes CLU , PICALM, BIN1, CR1, ABCA7, MS4A6A, MS4A4E, CD2AP, EPHA1, and CD33. We constructed a genetic risk score by adding the risk alleles per individual weighted by the reported effect sizes. All people underwent cognitive testing. With linear regression we investigated the relationship between the genetic risk score and cognition, with and without APOE . In a subcohort, with more than 10 years of follow-up, we assessed whether the risk score predicted AD. Results The genetic risk score was primarily associated with memory (standardized difference [95% confidence interval] per SD increase in genetic risk score: −.05[−.07; −.02], p = 1.5 * 10 −4 ). This association attenuated when APOE was excluded from the genetic risk score (−.03[−.05; .00], p = .047) and would not survive a multiple-testing correction. Similarly, we found that although the genetic risk score without APOE was associated with the development of AD ( p = .010), it only marginally improved prediction of AD beyond age, sex, APOE (area under the curve: .8159 vs. .8148). Conclusions In nondemented people, there is only a marginal joint effect of AD genes on memory independent from APOE . Moreover, although associated with AD, these genes jointly hardly improve prediction of AD.

Dementia is of increasing medical and societal relevance. Hospitalization of dementia patients is mostly due to behavioral and psychological symptoms of dementia (BPSD). There is a need for sufficient qualified personnel in hospitals in order to be able to effectively treat these symptoms.This study aims at identifying the personnel requirements for guideline-conform, evidence-based inpatient treatment concepts for patients with BPSD and to compare these with the resources defined by the German psychiatric personnel regulations (Psych-PV). Furthermore, it was the aim to identify how often patients with dementia received non-pharmacological therapy during inpatient treatment.Based on the current scientific evidence for treatment of BPSD, a schedule for a multimodal non-pharmacological treatment was defined and based on this the corresponding personnel requirements were calculated. Using the treatment indicators in psychiatry and psychosomatics (VIPP) database as a reference, it was calculated on what proportion of treatment days patients were classified into G1 according to the German Psych-PV and at least once received more than two treatment units per week.For the implementation of a guideline-oriented and evidence-based treatment plan, a higher need for personnel resources than that provided by the Psych-PV was detected in all areas. Currently patients with dementia who received at least more than two treatment units per week during inpatient hospitalization, were classified into G1 according to German Psych-PV on 17.9 % of treatment days.Despite evidence for the efficacy of non-pharmacological treatment measures on BPSD, these forms of treatment cannot be sufficiently provided under the current conditions. The realization of a new quality controlled therapeutic concept is necessary to enable optimized treatment of patients with BPSD.

International audience; We determined the value of hippocampus (Hp) and basal forebrain (BF) volumes for predicting cognitive decline and treatment response in a double-blind, randomized, placebo-controlled phase 4 trial at 28 academic centers (France) in patients with amnestic mild cognitive impairment (MCI) receiving Donepezil 10 mg daily or placebo over 12 months, and 6 months open label follow-up. Outcome measures were the rates of global and domain specific cognitive decline as non-primary efficacy endpoint. The intention-to-treat (ITT) sample analyzed comprised 215 cases. Baseline Hp volume was a significant predictor of rates of change in global cognitive function in linear mixed effects models. This effect was independent of treatment. BF volume was not associated with rates of global or domain specific cognitive decline. Rates of delayed free recall decline were higher in MCI cases treated with donepezil compared to placebo. Only Hp, but not BF volume was a useful predictor of cognitive decline in suspected prodromal AD patients. Both Hp and BF volumes were poor predictors of treatment response, questioning previous approaches on predicting treatment response without placebo control. clinicalTrials.gov Identifier NCT00403520.

Background It is unknown whether longitudinal stability versus instability in subjective cognitive decline (SCD) is a modifying factor of the association between SCD and risk of incident Alzheimer's disease (AD) dementia. Objective We tested the modifying role of temporal stability of the SCD report on AD dementia risk in cognitively normal elderly individuals. Methods We analyzed data of 1,990 cognitively normal participants from the longitudinal AgeCoDe Study. We assessed SCD with/without associated worries both at baseline and first follow-up 18 months later. Participants were then classified either as (a) Controls (CO, with no SCD at both baseline and follow-up 1, n = 613), (b) inconsistent SCD (with SCD reported only at baseline or at follow-up 1, n = 637), (c) consistent SCD but without/or with inconsistent worries (n = 610) or (d) consistent SCD with worries (n = 130). We estimated incident AD dementia risk over up to 6 years for each group with Cox-Proportional Hazard Regression analyses adjusted for age, gender, education, ApoE4 status, and depression. Results Compared to CO, inconsistent SCD was not associated with increased risk of incident AD dementia. In contrast, risk was doubled in the group of consistent SCD without/ with inconsistent worries, and almost 4-fold in the group of consistent SCD with worries. These results could be replicated when using follow-up 1 to follow-up 2 response patterns for group definition. Conclusion These findings suggest that longitudinal stability versus instability is an important modifying factor of the association between SCD and AD dementia risk. Worrisome SCD that is also consistently reported over time is associated with greatly increased risk of AD dementia.

Background There are various definitions and diagnostic criteria for dementia, leading to discrepancies in case ascertainment in both clinical practice and research. We reviewed the different definitions, approaches and measurements used to operationalize dementia in health care studies in German nursing homes with the aim of discussing the implications of different approaches. Methods We conducted a systematic search of the MEDLINE and CINAHL databases to identify pre-2016 studies conducted in German nursing homes that focused on residents with dementia or cognitive impairment. In- or exclusion of studies were consented by all authors; data extraction was independently carried out by 2 authors (RP, SJ). The studies’ sampling methods were compared with respect to their inclusion criteria, assessment tools and methods used to identify the study population. Results We summarized case ascertainment methods from 64 studies. Study participants were identified based on a diagnosis that was evaluated during the study, or a recorded medical dementia diagnosis, or a recorded medical diagnosis either with additional cognitive screenings or using screening tests exclusively. The descriptions of the diagnostics that were applied to assess a diagnosis of dementia were not fully transparent in most of the studies with respect to either a clear reference definition of dementia or applied diagnostic criteria. If reported, various neuropsychological tests were used, mostly without a clear rationale for their selection. Conclusion Pragmatic considerations often determine the sampling strategy; they also may explain the variances we detected in the different studies. Variations in sampling methods impede the comparability of study results. There is a need to consent case ascertainment strategies in dementia studies in health service research in nursing homes. These strategies should consider resource constraints and ethical issues that are related to the vulnerable population of nursing home residents. Additionally, reporting about dementia studies in nursing homes need to be improved. If a diagnosis cannot be evaluated based on either ICD or DSM criteria, the study population may not be reported as having dementia. If a diagnosis is evaluated based on ICD or DSM criteria within the study, there is a need for more transparency of the diagnostic process. Electronic supplementary material The online version of this article (doi:10.1186/s12877-016-0249-7) contains supplementary material, which is available to authorized users.

Background Recent studies demonstrated benefits of cognitive intervention in mild cognitive impairment (MCI), but few studies have determined long-term effects on cognition, conversion rate to Alzheimer's disease, and the role of early intervention. Method A 6-month multicomponent cognitive group intervention was applied in participants with single- or multiple-domain amnestic MCI (defined according to Petersen's criteria). One group (n = 12) received the intervention at the beginning of the study period and was compared with an active control group (n = 12) who received it after an 8-month time lag. Follow-up assessments were conducted at 15 and 28 months (study period was August 2007-December 2009). The primary outcome was change in cognitive function as determined by changes in scores on the Mini-Mental State Examination and the cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-cog), and the secondary outcomes were change in specific cognitive and noncognitive functions and conversion to Alzheimer's disease (according to DSM-IV/NINCDS-ADRDA criteria and NAI-AA criteria for probable Alzheimer's dementia with increased level of certainty). Results Eighteen participants completed the study after 28 months. Long-term data revealed a stable intervention effect on the primary outcome ADAS-cog in the early-intervention group (P = .024). The participants in the later-intervention (control) group appeared to benefit to a lesser extent from the cognitive intervention compared to those who received it earlier. Only participants in the later-intervention group (6 of 12) converted to Alzheimer's disease during the 28-month study period. Conclusions Benefits of our 6-month cognitive intervention on global cognitive status appear to be preserved over extended follow-up periods. Early cognitive intervention may delay conversion to Alzheimer's disease. Findings in a small sample encourage the use of the intervention in larger-scale studies. Trial registration ClinicalTrials.gov identifier: NCT00544856.

Increased degradation of tryptophan (TRP) through the kynurenine (KYN) pathway (KP) is known to be involved in the molecular mechanisms resulting in the neuropathogenesis of Alzheimer's disease (AD). Activation of the KP leads to the production of neurotoxic metabolites 3-hydroxykynurenine (3-HK) and quinolinic acid (QUIN) by immune cells and neuroprotective derivates kynurenic acid (KYNA) and picolinic acid (PIC) by astrocytes and neurons. We therefore investigated whether an imbalance between neurotoxic and neuroprotective kynurenine metabolites could be detected in patients with AD. We measured serum levels of TRP, KYNA, 3-HK, PIC and QUIN in 20 patients with AD and for comparison in 20 patients with major depression, and 19 subjectively cognitive impaired subjects. Serum levels of 3-HK were markedly increased in AD patients compared to the comparison groups (p < .0001). Serum levels of the other KP metabolites were not significantly different between groups. Our data indicate an increased production of the neurotoxic KP metabolite 3-HK in AD. In contrast to its downstream metabolites QUIN and PIC, 3-HK can cross the blood-brain barrier via an active transport process. Our data therefore indicate an enhanced availability of 3-HK in the brain of AD patients, which may be related to the previously reported higher production of QUIN in AD brains.

Alzheimer's disease (AD) is characterized by the extracellular deposition of amyloid-β (Aβ), neurofibrillary tangle formation, and a microglial-driven inflammatory response. Chronic inflammatory activation compromises microglial clearance functions. Because peroxisome proliferator-activated receptor γ (PPARγ) agonists suppress inflammatory gene expression, we tested whether activation of PPARγ would also result in improved microglial Aβ phagocytosis. The PPARγ agonist pioglitazone and a novel selective PPARα/γ modulator, DSP-8658, currently in clinical development for the treatment of type 2 diabetes, enhanced the microglial uptake of Aβ in a PPARγ-dependent manner. This PPARγ-stimulated increase of Aβ phagocytosis was mediated by the upregulation of scavenger receptor CD36 expression. In addition, combined treatment with agonists for the heterodimeric binding partners of PPARγ, the retinoid X receptors (RXRs), showed additive enhancement of the Aβ uptake that was mediated by RXRα activation. Evaluation of DSP-8658 in the amyloid precursor protein/presenilin 1 mouse model confirmed an increased microglial Aβ phagocytosisin vivo, which subsequently resulted in a reduction of cortical and hippocampal Aβ levels. Furthermore, DSP-8658-treated mice showed improved spatial memory performance. Therefore, stimulation of microglial clearance by simultaneous activation of the PPARγ/RXRα heterodimer may prove beneficial in prevention of AD.

Diffusion tensor imaging (DTI) detects microstructural changes of the cerebral white matter in Alzheimer's disease (AD). The use of DTI for the diagnosis of AD in a multicenter setting has not yet been investigated. We used voxel-based analysis of fractional anisotropy, mean diffusivity, and grey matter volumes from multimodal magnetic resonance imaging data of 137 AD patients and 143 healthy elderly controls collected across 9 different scanners. We compared different univariate analysis approaches to model the effect of scanner, including a linear model across all scans with a scanner covariate, a random effects model with scanner as a random variable as well as a voxel-based meta-analysis. We found significant reduction of fractional anisotropy and significant increase of mean diffusivity in core areas of AD pathology including corpus callosum, medial and lateral temporal lobes, as well as fornix, cingulate gyrus, precuneus, and prefrontal lobe white matter. Grey matter atrophy was most pronounced in medial and lateral temporal lobe as well as parietal and prefrontal association cortex. The effects of group were spatially more restricted with random effects modeling of scanner effects compared to simple pooled analysis. All three analysis approaches yielded similar accuracy of group separation in block-wise cross-validated logistic regression. Our results suggest similar effects of center on group separation based on different analysis approaches and confirm a typical pattern of cortical and subcortical microstructural changes in AD using a large multimodal multicenter data set.

Midlife motivational abilities, that is, skills to initiate and persevere in the implementation of goals, have been related to mental and physical health, but their association with risk of mild cognitive impairment (MCI) and Alzheimer's disease (AD) has not yet been directly investigated. This relation was examined with data from the German Study on Ageing, Cognition, and Dementia in Primary Care Patients (AgeCoDe). A total of 3,327 nondemented participants (50.3% of a randomly selected sample) aged 75-89 years were recruited in primary care and followed up twice (after 1.5 and 3 years). Motivation-related occupational abilities were estimated on the basis of the main occupation (assessed at follow-up II) using the Occupational Information Network (O* NET) database, which provides detailed information on worker characteristics and abilities. Cox proportional hazards models were used to evaluate the relative risk of developing MCI and AD in relation to motivation-related occupational abilities, adjusting for various covariates. Over the 3 years of follow-up, 15.2% participants developed MCI and 3.0% developed AD. In a fully adjusted model, motivation-related occupational abilities were found to be associated with a reduced risk of MCI (HR: 0.77; 95% CI: 0.64-0.92). Motivation-related occupational abilities were associated with reduced risk of AD in ApoE ε4 carriers (HR: 0.48; CI: 0.25-0.91), but not in noncarriers (HR: 0.99; CI: 0.65-1.53). These results suggest that midlife motivational abilities are associated with reduced risk of MCI in general and with reduced risk of AD in ApoE ε4 carriers. Revealing the mechanisms underlying this association may inform novel prevention strategies for decelerating cognitive decline in old age.

Although the prevalence of dementia continues to increase worldwide, incidence in the western world might have decreased as a result of better vascular care and improved brain health. Alzheimer's disease, the most prevalent cause of dementia, is still defined by the combined presence of amyloid and tau, but researchers are gradually moving away from the simple assumption of linear causality as proposed in the original amyloid hypothesis. Age-related, protective, and disease-promoting factors probably interact with the core mechanisms of the disease. Amyloid β42, and tau proteins are established core cerebrospinal biomarkers; novel candidate biomarkers include amyloid β oligomers and synaptic markers. MRI and fluorodeoxyglucose PET are established imaging techniques for diagnosis of Alzheimer's disease. Amyloid PET is gaining traction in the clinical arena, but validity and cost-effectiveness remain to be established. Tau PET might offer new insights and be of great help in differential diagnosis and selection of patients for trials. In the search for understanding the disease mechanism and keys to treatment, research is moving increasingly into the earliest phase of disease. Preclinical Alzheimer's disease is defined as biomarker evidence of Alzheimer's pathological changes in cognitively healthy individuals. Patients with subjective cognitive decline have been identified as a useful population in whom to look for preclinical Alzheimer's disease. Moderately positive results for interventions targeting several lifestyle factors in non-demented elderly patients and moderately positive interim results for lowering amyloid in pre-dementia Alzheimer's disease suggest that, ultimately, there will be a future in which specific anti-Alzheimer's therapy will be combined with lifestyle interventions targeting general brain health to jointly combat the disease. In this Seminar, we discuss the main developments in Alzheimer's research.

Background: The recently proposed latent variable δ is a new tool for dementia case finding. It is built in a structural equation modeling framework of cognitive and functional data and constitutes a novel endophenotype for Alzheimer’s disease (AD) research and clinical trials. Objective: To investigate the association of δ with AD biomarkers and to compare the prediction of δ with established scales for conversion to dementia in patients with mild cognitive impairment (MCI). Methods: Using data from a multicenter memory clinic study, we examined the external associations of the latent variable δ and compared δ with well-established cognitive and functional scales and cognitive-functional composite scores. For that purpose, logistic regressions with cerebrospinal fluid (CSF) biomarkers and conversion to dementia as dependent variables were performed with the investigated scores. The models were tested for significant differences. Results: In patients with MCI, δ based on a broad range of cognitive scales (including the ADAS-cog, the MMSE, and the CERAD neuropsychological battery) predicted an abnormal CSF Aβ42/tau ratio indicative of AD (n = 340, AUC = 0.78, p < 0.001), and predicted incident dementia within 1–3 years of follow-up (n = 525, AUC = 0.84, p < 0.001). These associations were generally stronger than for any other scale or cognitive-functional composite examined. Homologs of δ based on reduced test batteries yielded somewhat lower effects. Conclusion: These findings support the interpretation of δ as a construct capturing the disease-related “essence” of cognitive and functional impairments in patients with MCI and dementia, and suggest that δ might become an analytical tool for dementia research.

Regional dementia care networks become more and more important in the care for community-dwelling persons with dementia (PwD). However, the quality of life of PwD, served by dementia care networks, has not been investigated yet. It also remains unclear if there are differences between urban and rural dementia care networks. This study therefore aims at investigating the quality of life of PwD using this care model, also regarding possible regional differences.Within the DemNet-D-Study, PwD and their primary caregivers were interviewed using typical outcome parameters (quality of life: QoL-AD, depression: GDS, challenging behaviour: CMAI, capacities of daily living: IADL, caregiver burden: BIZA-D). In addition to these parameters, regional differences were analysed using multi-level-analysis.In total, 560 PwD (79.7 years; 57.0 % female) and their caregivers participated in the study. Both self- and proxy-rated quality of life is on a moderate level. The analysis shows a sufficient explanation of the quality of life. (self: p0.001, R2=0.493; proxy: p0.001, R2=0.406). Higher quality of life was found for PwD living together with their care givers and for those PwD with higher capacities of daily living. Regional (urban vs. rural) differences could not be found.The quality of life of community-dwelling PwD using regional dementia care networks is comparable to those in other studies of outpatient dementia care. Further investigation should be carried out regarding different types of dementia care networks.