Correlations between kynurenines in plasma and CSF, and their relation to markers of Alzheimer's disease pathology.

INTRODUCTION: Altered levels of kynurenines in blood and cerebrospinal fluid (CSF) have been reported in Alzheimer's disease (AD). However, it is still largely unknown whether peripheral kynurenine concentrations resemble those found in CSF and how they relate to AD pathology. We therefore studied correlations between kynurenines in plasma and CSF and their associations with CSF amyloid-beta (Aß1-42) and tau levels in patients from the memory clinic spanning the whole cognitive spectrum. METHODS: The Biobank Alzheimer Center Limburg study is a prospective cohort study of consecutive patients referred to the memory clinic of the Alzheimer Center Limburg. Plasma and CSF concentrations of tryptophan (TRP), eight kynurenines and neopterin from 138 patients were determined by means of LC-MS/MS. Additionally, CSF Aß1-42, total-tau (t-tau) and phosphorylated tau (p-tau) concentrations were determined using commercially available single-parameter ELISA methods. Partial correlations were used to analyze cross-sectional associations between kynurenines in plasma and CSF and their relation to AD related CSF-biomarkers adjusted for age, sex, educational level, and kidney function. RESULTS: Moderate to strong correlations were observed between plasma and CSF levels for quinolinic acid (QA; r = 0.63), TRP (r = 0.47), anthranilic acid (r = 0.59), picolinic acid (r = 0.55), and the kynurenine (KYN)/TRP ratio (KTR; r = 0.55; all p < 0.0001), while other kynurenines correlated only weakly with their corresponding CSF values. No correlations were found between plasma and CSF levels of KA/QA. Several kynurenines were also weakly correlated with Aß1-42, t-tau or p-tau. Plasma levels of KA/QA were negatively correlated with Aß1-42 (r = -0.21, p < 0.05). Plasma levels of TRP were negatively correlated with t-tau (r = -0.19) and levels of KYN with p-tau (r = -0.18; both p < 0.05). CSF levels of KYN (r = 0.20, p < 0.05), KA (r = 0.23, p < 0.01), and KTR (r = 0.18, p < 0.05) were positively correlated with Aß1-42. Finally, TRP and KYN were negatively (r = -0.22 and r = -0.18, respectively), and neopterin positively (r = 0.19) correlated with p-tau (all p < 0.05). CONCLUSIONS: Plasma concentrations of TRP, KP metabolites, KTR, and neopterin all significantly correlated positively with their corresponding CSF concentrations, but many correlations were weak. Additionally, our results suggest a relation between higher kynurenine levels and lower AD pathology load. These results need verification in future studies and require more research into (shared) underlying mechanisms.

Tear biomarkers for Alzheimer's disease screening and diagnosis (the TearAD study): design and rationale of an observational longitudinal multicenter study.

BACKGROUND: Alzheimer's disease (AD) is the most common cause of dementia, and due to increasing life expectancy the number of patients is expected to grow. The diagnosis of AD involves the use of biomarkers determined by an amyloid PET scan or cerebrospinal fluid analyses that are either invasive or expensive, and not available in each hospital, thus limiting their usage as a front-line screener. The TearAD study aims to use tear fluid as a potential source for AD biomarkers. In previous reports, we demonstrated that AD biomarkers amyloid-beta and tau, are measurable in tear fluid and are associated with disease severity and neurodegeration. This study aims to validate previous results in a larger cohort and evaluate the diagnostic accuracy of tear biomarkers to discriminate between individuals with and without neurodegeneration as determined by hippocampal atrophy. METHODS: The TearAD study is an observational longitudinal multi-center study that will enroll 50 cognitively healthy controls, 50 patients with subjective cognitive decline, 50 patients with mild cognitive impairment and 50 patients with AD dementia from the memory clinic. Participants will be examined at baseline, after one year, and after two years follow-up. Study assessments include neuropsychological tests and ophthalmic examination. All participants will receive a MRI scan, and a subset of the study population will undergo cerebral spinal fluid collection and an amyloid PET scan. Tear fluid will be collected with Schirmer strips and levels of Aß38, Aß40, Aß42, t-tau and p-tau in tear fluid will be determined using multiplex immunoassays. Blood samples will be collected from all participants. Images of the retina will be obtained with a standard, hyperspectral and ultra-wide field fundus camera. Additionally, macular pigment optical density will be measured with the macular pigment reflectometer, and cross-sectional images of the retina will be obtained through optical coherence tomography imaging. DISCUSSION: The TearAD study will provide insight into the potential diagnostic use of tear biomarkers as a minimally invasive and low cost tool for the screening and diagnosis of AD. TRIAL REGISTRATION: Retrospectively registered at clinicaltrials.gov (NCT05655793).

Determinants of quality of life in family caregivers in MCI: a comparison with mild dementia.

OBJECTIVES: The aim of the current study was to investigate the health-related quality of life (HRQol) of the family caregiver in MCI, explore possible determinants and study possible differences with mild dementia. METHODS: This secondary data analysis included 145 persons with MCI and 154 persons with dementia and their family caregivers from two Dutch cohort studies. HRQoL was measured with the VAS of the EuroQol-5D-3L version. Regressions analyses were conducted to examine potential demographic and clinical determinants of the caregiver's HRQoL. RESULTS: The mean EQ5D-VAS in family caregivers of persons with MCI was 81.1 (SD 15.7), and did not significantly differ from family caregivers in mild dementia (81.9 (SD 13.0)). In MCI, patient measurements were not significantly associated with caregiver mean EQ5D-VAS. Concerning caregiver characteristics, being a spouse and a lower educational level were associated with a lower mean EQ5D-VAS (in a multiple linear regression model: unstandardized B -8.075, p = 0.013 and unstandardized B -6.162, p = 0.037 resp.). In mild dementia, the NPI item irritability showed an association with caregiver EQ5D-VAS in bivariate linear regression analyses. CONCLUSION: Results indicate that especially family caregiver characteristics seem to influence family caregiver HRQoL in MCI. Future research should include other potential determinants such as burden, coping strategies and relationship quality.

The value of maintaining cognition in patients with mild cognitive impairment: The innovation headroom and potential cost-effectiveness of roflumilast.

INTRODUCTION: Early health-technology assessment can support discussing scarce resource allocation among stakeholders. We explored the value of maintaining cognition in patients with mild cognitive impairment (MCI) by estimating: (1) the innovation headroom and (2) the potential cost effectiveness of roflumilast treatment in this population. METHODS: The innovation headroom was operationalized by a fictive 100% efficacious treatment effect, and the roflumilast effect on memory word learning test was assumed to be associated with 7% relative risk reduction of dementia onset. Both were compared to Dutch setting usual care using the adapted International Pharmaco-Economic Collaboration on Alzheimer's Disease (IPECAD) open-source model. RESULTS: The total innovation headroom expressed as net health benefit was 4.2 (95% bootstrap interval: 2.9-5.7) quality-adjusted life years (QALYs). The potential cost effectiveness of roflumilast was k€34 per QALY. DISCUSSION: The innovation headroom in MCI is substantial. Although the potential cost effectiveness of roflumilast treatment is uncertain, further research on its effect on dementia onset is likely valuable.

A Scoping Review of Communicating Neuropsychological Test Results to Patients and Family Members.

Feedback of neuropsychological test results to patients and family members include psychoeducation and implications for daily life. This scoping review aimed to provide an overview of the literature on neuropsychological feedback and to offer clinical recommendations. In accordance with formal scoping review methodology, PubMed, PsycInfo, Web of Science, CINAHL, and Embase databases were searched. Studies were included if they reported on neuropsychological feedback, if full papers were available, and if they included human participants. All languages were included, and no limit was placed on the year of publication. Of the 2,173 records screened, 34 publications met the inclusion criteria. Five additional publications were included after cross-referencing. An update of the search led to the inclusion of two additional papers. Of these 41 publications, 26 were research papers. Neuropsychological feedback is provided for a wide spectrum of diagnoses and usually given in-person and has been related to optimal a positive effect on patient outcomes (e.g. increase the quality of life). Most papers reported on satisfaction and found that satisfaction with an NPA increased when useful feedback was provided. However, information retention was found to be low, but communication aids, such as written information, were found to be helpful in improving retention. The current review demonstrated the benefits of neuropsychological feedback and that this should be part of standard clinical procedures when conducting a neuropsychological assessment. Further research on the benefits of neuropsychological feedback and how to improve information provision would enrich the neuropsychological literature.

Alzheimer's disease pathology: pathways between central norepinephrine activity, memory, and neuropsychiatric symptoms.

The locus coeruleus (LC) supplies norepinephrine to the brain, is one of the first sites of tau deposition in Alzheimer's disease (AD) and modulates a variety of behaviors and cognitive functions. Transgenic mouse models showed that norepinephrine dysregulation after LC lesions exacerbates inflammatory responses, blood-brain barrier leakage (BBB), and cognitive deficits. Here, we investigated relationships between central norepinephrine metabolism, tau and beta-amyloid (Aß), inflammation, BBB-dysfunction, neuropsychiatric problems, and memory in-vivo in a memory clinic population (total n = 111, 60 subjective cognitive decline, 36 mild cognitively impaired, and 19 AD dementia). Cerebrospinal fluid (CSF) and blood samples were collected and analyzed for 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG), CSF/plasma albumin ratio (Q-alb), Aß, phosphorylated tau, and interleukins. The verbal word learning task and the neuropsychiatric inventory assessed memory functioning and neuropsychiatric symptoms. Structural equation models tested the relationships between all fluid markers, cognition and behavior, corrected for age, education, sex, and clinical dementia rating score. Our results showed that neuropsychiatric symptoms show strong links to both MHPG and p-tau, whereas memory deficits are linked to MHPG via a combination of p-tau and inflammation-driven amyloidosis (30-35% indirect effect contribution). These results suggest that the LC-norepinephrine may be pivotal to understand links between AD pathology and behavioral and cognitive deficits in AD.

A comparison of two approaches for modeling dementia progression in a changing patient context.

OBJECTIVES: To explain the heterogeneity in dementia disease trajectory, we studied the influence of changing patient characteristics on disease course by comparing the association of dementia progression with baseline comorbidity and frailty, and with time-varying comorbidity and frailty. METHODS: We used individual growth models to study baseline and time-varying associations in newly diagnosed dementia patients (n = 331) followed for 3 years. We measured cognition using the Mini-Mental State Examination (MMSE), daily functioning using the Disability Assessment for Dementia (DAD), frailty using the Fried criteria and comorbidity using the Cumulative Illness Rating Scale for Geriatrics (CIRS-G). RESULTS: Although baseline comorbidity and frailty were associated with decreased daily functioning at diagnosis, their effects clearly diminished over time. In contrast, when incorporating comorbidity and frailty as time-varying covariates, comorbidity was associated with lower daily functioning, and frailty with both lower cognition and daily functioning. Being frail was associated with a 0.9-point lower MMSE score (p = 0.03) and a 14.9-point lower DAD score (p < 0.01). A 1-point increase in CIRS-G score was associated with a 1.1-point lower DAD score (p < 0.01). CONCLUSIONS: Time-varying comorbidity and frailty were more consistently associated with dementia disease course than baseline comorbidity and frailty. Therefore, modeling only baseline predictors is insufficient for understanding the course of dementia in a changing patient context.

Cerebrospinal fluid proteomic profiling of individuals with mild cognitive impairment and suspected non-Alzheimer's disease pathophysiology.

BACKGROUND: Suspected non-Alzheimer's disease pathophysiology (SNAP) is a biomarker concept that encompasses individuals with neuronal injury but without amyloidosis. We aim to investigate the pathophysiology of SNAP, defined as abnormal tau without amyloidosis, in individuals with mild cognitive impairment (MCI) by cerebrospinal fluid (CSF) proteomics. METHODS: Individuals were classified based on CSF amyloid beta (Aß)1-42 (A) and phosphorylated tau (T), as cognitively normal A-T- (CN), MCI A-T+ (MCI-SNAP), and MCI A+T+ (MCI-AD). Proteomics analyses, Gene Ontology (GO), brain cell expression, and gene expression analyses in brain regions of interest were performed. RESULTS: A total of 96 proteins were decreased in MCI-SNAP compared to CN and MCI-AD. These proteins were enriched for extracellular matrix (ECM), hemostasis, immune system, protein processing/degradation, lipids, and synapse. Fifty-one percent were enriched for expression in the choroid plexus. CONCLUSION: The pathophysiology of MCI-SNAP (A-T+) is distinct from that of MCI-AD. Our findings highlight the need for a different treatment in MCI-SNAP compared to MCI-AD.

Harmonizing neuropsychological assessment for mild neurocognitive disorders in Europe.

INTRODUCTION: Harmonized neuropsychological assessment for neurocognitive disorders, an international priority for valid and reliable diagnostic procedures, has been achieved only in specific countries or research contexts. METHODS: To harmonize the assessment of mild cognitive impairment in Europe, a workshop (Geneva, May 2018) convened stakeholders, methodologists, academic, and non-academic clinicians and experts from European, US, and Australian harmonization initiatives. RESULTS: With formal presentations and thematic working-groups we defined a standard battery consistent with the U.S. Uniform DataSet, version 3, and homogeneous methodology to obtain consistent normative data across tests and languages. Adaptations consist of including two tests specific to typical Alzheimer's disease and behavioral variant frontotemporal dementia. The methodology for harmonized normative data includes consensus definition of cognitively normal controls, classification of confounding factors (age, sex, and education), and calculation of minimum sample sizes. DISCUSSION: This expert consensus allows harmonizing the diagnosis of neurocognitive disorders across European countries and possibly beyond.

Associations between plasma kynurenines and cognitive function in individuals with normal glucose metabolism, prediabetes and type 2 diabetes: the Maastricht Study.

AIMS/HYPOTHESIS: Studies investigating associations between kynurenines and cognitive function have generally been small, restricted to clinical samples or have found inconsistent results, and associations in the general adult population, and in individuals with type 2 diabetes in particular, are not clear. Therefore, the aim of the present study was to investigate cross-sectional associations between plasma kynurenines and cognitive function in a cohort of middle-aged participants with normal glucose metabolism, prediabetes (defined as impaired fasting glucose and/or impaired glucose tolerance) and type 2 diabetes. METHODS: Plasma kynurenines were quantified in 2358 participants aged 61 ± 8 years. Cross-sectional associations of kynurenines with cognitive impairment and cognitive domain scores were investigated using logistic, multiple linear and restricted cubic spline regression analyses adjusted for several confounders. RESULTS: Effect modification by glucose metabolism status was found for several associations with cognitive impairment, hence analyses were stratified. In individuals with prediabetes, 3-hydroxykynurenine (OR per SD 0.59 [95% CI 0.37, 0.94]) and 3-hydroxyanthranilic acid (0.67 [0.47, 0.96]) were associated with lower odds of cognitive impairment after full adjustment. In individuals with type 2 diabetes, kynurenine (0.80 [0.66, 0.98]), 3-hydroxykynurenine (0.82 [0.68, 0.99]), kynurenic acid (0.81 [0.68, 0.96]), xanthurenic acid (0.73 [0.61, 0.87]) and 3-hydroxyanthranilic acid (0.73 [0.60, 0.87]) were all associated with lower odds of cognitive impairment. Kynurenic acid (ß per SD 0.07 [95% CI 0.02, 0.13]) and xanthurenic acid (0.06 [0.01, 0.11]) were also associated with better executive function/attention. No associations were observed in individuals with normal glucose metabolism. CONCLUSIONS/INTERPRETATION: Several kynurenines were cross-sectionally associated with lower odds of cognitive impairment and better cognitive functioning in type 2 diabetes, while less widespread associations were seen in prediabetes. Low levels of kynurenines might be involved in the pathway of type 2 diabetes and cognitive decline but this needs further studies.

Alzheimer's disease biomarkers as predictors of trajectories of depression and apathy in cognitively normal individuals, mild cognitive impairment, and Alzheimer's disease dementia.

OBJECTIVES: To examine trajectories of depression and apathy over a 5-year follow-up period in (prodromal) Alzheimer's disease (AD), and to relate these trajectories to AD biomarkers. METHODS: The trajectories of depression and apathy (measured with the Neuropsychiatric Inventory or its questionnaire) were separately modeled using growth mixture models for two cohorts (National Alzheimer's Coordinating Center, NACC, n = 22 760 and Alzheimer's Disease Neuroimaging Initiative, ADNI, n = 1 733). The trajectories in ADNI were associated with baseline CSF AD biomarkers (Aß42, t-tau, and p-tau) using bias-corrected multinomial logistic regression. RESULTS: Multiple classes were identified, with the largest classes having no symptoms over time. Lower Aß42 and higher tau (ie, more AD pathology) was associated with increased probability of depression and apathy over time, compared to classes without symptoms. Lower Aß42 (but not tau) was associated with a steep increase of apathy, whereas higher tau (but not Aß42 ) was associated with a steep decrease of apathy. DISCUSSION: The trajectories of depression and apathy in individuals on the AD spectrum are associated with AD biomarkers.

Obtaining EQ-5D-5L utilities from the disease specific quality of life Alzheimer's disease scale: development and results from a mapping study.

PURPOSE: The Quality of Life Alzheimer's Disease Scale (QoL-AD) is commonly used to assess disease specific health-related quality of life (HRQoL) as rated by patients and their carers. For cost-effectiveness analyses, utilities based on the EQ-5D are often required. We report a new mapping algorithm to obtain EQ-5D indices when only QoL-AD data are available. METHODS: Different statistical models to estimate utility directly, or responses to individual EQ-5D questions (response mapping) from QoL-AD, were trialled for patient-rated and proxy-rated questionnaires. Model performance was assessed by root mean square error and mean absolute error. RESULTS: The response model using multinomial regression including age and sex, performed best in both the estimation dataset and an independent dataset. CONCLUSIONS: The recommended mapping algorithm allows researchers for the first time to estimate EQ-5D values from QoL-AD data, enabling cost-utility analyses using datasets where the QoL-AD but no utility measures were collected.

The Association Between Biomarkers and Neuropsychiatric Symptoms Across the Alzheimer's Disease Spectrum.

OBJECTIVE: To investigate the relationship between Alzheimer's disease biomarkers and neuropsychiatric symptoms. METHODS: Data from two large cohort studies, the Dutch Parelsnoer Institute - Neurodegenerative Diseases and the Alzheimer's Disease Neuroimaging Initiative was used, including subjects with subjective cognitive decline (N = 650), mild cognitive impairment (N = 887), and Alzheimer's disease dementia (N = 626). Cerebrospinal fluid (CSF) levels of Aß42, t-tau, p-tau, and hippocampal volume were associated with neuropsychiatric symptoms (measured with the Neuropsychiatric Inventory) using multiple logistic regression analyses. The effect of the Mini-Mental State Examination (as proxy for cognitive functioning) on these relationships was assessed with mediation analyses. RESULTS: Alzheimer's disease biomarkers were not associated with depression, agitation, irritability, and sleep disturbances. Lower levels of CSF Aß42, higher levels of t- and p-tau were associated with presence of anxiety. Lower levels of CSF Aß42 and smaller hippocampal volumes were associated with presence of apathy. All associations were mediated by cognitive functioning. CONCLUSION: The association between Alzheimer's disease pathology and anxiety and apathy is partly due to impairment in cognitive functioning.

Determinants of Cross-Sectional and Longitudinal Health-Related Quality of Life in Memory Clinic Patients Without Dementia.

OBJECTIVE: To identify determinants within 3 different domains (ie, somatic comorbidities, cognitive functioning, and neuropsychiatric symptoms [NPS]) of health-related quality of life (HRQoL) over time in memory clinic patients without dementia. METHODS: This longitudinal multicenter cohort study with a 3-year observation period recruited 315 individuals (age: 69.8 ± 8.6, 64.4% males, Mini-Mental State Examination score 26.9 ± 2.6). A multivariable explanatory model was built using linear mixed effects models (forward selection per domain) to select determinants for self-perceived HRQoL over time, as measured by the EuroQoL-5D visual analogue scale (EQ VAS). RESULTS: Mean HRQoL at study entry was 69.4 ± 15.6. The presence of agitation, appetite and eating abnormalities, and eyes/ears/nose (ie, sensory impairment) comorbidities were associated with a change in HRQoL over time. Agitation was most strongly associated with HRQoL over time. CONCLUSIONS: The association of somatic comorbidities and NPS in memory clinic patients with course of HRQoL shows that these should receive more awareness, detection, and monitoring by clinicians.

A survey on the prevalence of apathy in elderly people referred to specialized memory centers.

BACKGROUND: Apathy is a pervasive neuropsychiatric syndrome in people with neurocognitive and psychiatric disorders. The diagnostic criteria for apathy (DCA) have been revised in 2018. OBJECTIVES: Employing the 2018 DCA, in the present study, we investigated in groups of elderly subjects suffering from different neuropsychiatric disorders (a) the apathy prevalence; (b) the most commonly affected apathy dimensions (behavior/cognition, emotion, and social interaction); (c) the sensitivity and specificity of those dimensions for apathy diagnosis; and (d) the concurrent validity of 2018 DCA compared with the 2009 DCA. METHODS: This multicenter survey included 166 subjects. Each center checked the presence of apathy in subjects belonging to the following DSM-5 diagnoses: mild neurocognitive disorders (mild NCDs); major NCDs; affective disorders (Aff D); and subjective cognitive decline (SCD). RESULTS: The frequency of apathy varied significantly based on the diagnostic groups (0% of subjects with apathy in the SCD group; 25% in the mild NCD group; 77% in the major NCD group; and 57% in the Aff. D group). All subjects with apathy fulfilled the criteria for the behavior/cognition dimension, 73.1% fulfilled the criteria for the emotion dimension, and 97.4% fulfilled the criteria for the social interaction dimension. Behavior/cognition showed the highest sensitivity, the copresence of emotion and social interaction the highest specificity. The concordance between the 2009 and the 2018 DCA indicated an almost perfect agreement. CONCLUSIONS: These results are consistent with previous reports and confirm that the social interaction dimension added to the 2018 DCA is present in most of subjects with apathy referred to specialized memory centers.

Cognitive and functional progression of dementia in two longitudinal studies.

OBJECTIVES: Previous studies have identified several subgroups (ie, latent trajectories) with distinct disease progression among people with dementia. However, the methods and results were not always consistent. This study aims to perform a coordinated analysis of latent trajectories of cognitive and functional progression in dementia across two datasets. METHODS: Included and analyzed using the same statistical approach were 1628 participants with dementia from the US National Alzheimer's Coordinating Center (NACC) and 331 participants with dementia from the Dutch Clinical Course of Cognition and Comorbidity study (4C-Study). Trajectories of cognition and instrumental activities of daily living (IADL) were modeled jointly in a parallel-process growth mixture model. RESULTS: Cognition and IADL tended to decline in unison across the two samples. Slow decline in both domains was observed in 26% of the US sample and 74% of the Dutch sample. Rapid decline in cognition and IADL was observed in 7% of the US sample and 26% of the Dutch sample. The majority (67%) of the US sample showed moderate cognitive decline and rapid IADL decline. CONCLUSIONS: Trajectories of slow and rapid dementia progression were identified in both samples. Despite using the same statistical methods, the number of latent trajectories was not replicated and the relative class sizes differed considerably across datasets. These results call for careful consideration when comparing progression estimates in the literature. In addition, the observed discrepancy between cognitive and functional decline stresses the need to monitor dementia progression across multiple domains.

Development of memory clinics in the Netherlands over the last 20 years.

OBJECTIVES: Memory clinics (MCs) have been established to improve diagnosis and treatment of cognitive disorders, including dementia. The aim of this study was to determine the characteristics and working methods of MCs in the Netherlands in 2016. More insight into different working methods can be used to improve the quality of care in Dutch MCs. Additionally, the findings will be compared with earlier results to investigate the development of MCs since 1998. METHODS: A survey was sent in 1998, 2004, 2009, and 2017 to all operational Dutch MCs with questions about organization, collaboration, patients, and diagnostic procedures. RESULTS: From 1998 to 2016, the number of MCs increased substantially from 12 to 91. The capacity increased from 1560 patients to 24,388. In 1998, most patients received a dementia diagnosis (85%), while in 2016, half of the patients were diagnosed with milder cognitive problems. MCs are more often part of regional care chains and are better embedded within regional care organizations. Diagnostic tools, such as blood tests (97%), neuropsychological assessment (NPA) (95%), and neuroimaging (92%), were used in nearly all MCs. The number of patients in whom these tools were used differed greatly between MCs (NPA: 5%-100%, neuroimaging: 10%-100%, and CSF: 0.5%-80%). There was an increase in the use of NPA, while the use of neuroimaging, CSF, and EEG/ECG decreased by 8% to 15% since 2009. CONCLUSIONS: Since 1998, MCs have developed substantially and outgrown the primarily research-based university settings. They are now accepted as regular care facilities for people with cognitive problems.

The clinical course and interrelations of dementia related symptoms.

ABSTRACTBackground:Dementia is a neurodegenerative syndrome that interferes with multiple aspects of life, including cognition, daily functioning, and behavior. Despite the large heterogeneity in symptom development, these three domains are seldom studied simultaneously. This study investigates how trajectories of these domains are interrelated within individuals over time, and how they in turn are related to dementia severity and quality of life (QoL). METHODS: We used data from a longitudinal clinical cohort study, including 331 dementia patients. Cognitive status was measured using the Mini-Mental State Examination, daily functioning was measured with the disability assessment for dementia and neuropsychiatric symptoms (NPS) were scored using the neuropsychiatric inventory. We investigated the relationships in the time course of the various dementia domains using random effects multilevel models and parallel-process growth models. RESULTS: Changes in cognition and daily functioning were highly correlated over time (r = 0.85, p < 0.01), as were changes in NPS and functioning (r = -0.60, p < 0.01), while changes in cognition and NPS were not (r = -0.20, p = 0.06). All three domains were strongly associated with dementia severity over time (p < 0.01). Decreased functioning and increased NPS were both associated with decreased QoL (ß = 2.97, p < 0.01 and ß = -2.41, p < 0.01, respectively), while cognition was not (ß = 0.01, p = 0.93). CONCLUSION: This study demonstrates the heterogeneity of dementia progression between individuals and between different dementia domains within individuals. To improve our understanding of dementia progression, future research should embrace a broader perspective encompassing multiple outcome measures along with the patient's profile, including neurological factors as well as physical, social, and psychiatric health.

Anxiety as a Predictor for Cognitive Decline and Dementia: A Systematic Review and Meta-Analysis.

BACKGROUND: Because anxiety is postulated as a risk factor for dementia, we performed a systematic review and meta-analysis to investigate whether anxiety predicts cognitive decline and/or dementia, taking the stage of cognitive decline as well as setting into account. METHODS: A systematic literature search up to January 2015 was performed to identify all longitudinal studies on the association between anxiety and cognition. Data extraction and methodological quality assessment were conducted independently by two authors. Where possible, pooled relative risks were calculated to examine anxiety as a possible risk factor for cognitive decline cognitive impairment and dementia in community studies (objective 1), as well as for conversion to dementia patients referred to memory clinics (objective 2). RESULTS: Twenty studies met inclusion criteria. Data on cognitive decline were too heterogeneous for meta-analysis. Anxiety predicted incident cognitive impairment (4 studies, relative risk [RR]: 1.77, 95% confidence interval [CI]: 1.38-2.26, z = 4.50, p < 0.001) and dementia (6 studies, RR: 1.57, 95% CI: 1.02-2.42, z = 2.05, p = 0.040) in the community, the latter driven by studies with a mean age of 80 years or above. Among clinical mild cognitive impairment samples, anxiety did not predict conversion to dementia (RR: 1.21, 95% CI: 0.90-1.63, z = 1.28, p = 0.200). CONCLUSIONS: Anxiety is associated with an increased risk for cognitive impairment and dementia in the community. Stronger associations were driven by higher age, suggesting that it is a prodromal symptom. Causal biological pathways have also been described, which could explain the risk for incident cognitive impairment in the community. Future studies should include mediating mechanism when studying anxiety as a predictor for cognitive decline and/or dementia.