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Sensory functions of organs of the head and neck allow humans to interact with the environment and establish social bonds. With aging, smell, taste, vision, and hearing decline. Evidence suggests that accelerated impairment in sensory abilities can reflect a shift from healthy to pathological aging, including the development of Alzheimer's disease (AD) and other neurological disorders. While the drivers of early sensory alteration in AD are not elucidated, insults such as trauma and infections can affect sensory function. Herein, we review the involvement of the major head and neck sensory systems in AD, with emphasis on microbes exploiting sensory pathways to enter the brain (the "gateway" hypothesis) and the potential feedback loop by which sensory function may be impacted by central nervous system infection. We emphasize detection of sensory changes as first-line surveillance in senior adults to identify and remove potential insults, like microbial infections, that could precipitate brain pathology. [ABSTRACT FROM AUTHOR]

INTRODUCTION: This study derived composite scores for two novel cognitive measures, the No Practice Effect (NPE) battery and the Miami Computerized Functional Skills Assessment and Training system for use in early‐stage Alzheimer's disease (AD) clinical trials. Their psychometric properties and associations with AD risk markers were compared to those of well‐established measures. METHODS: For 291 older adults with healthy cognition or early mild cognitive impairment, Exploratory factor analyses were used to identify the factor structure of the NPE. Factor and total scores were examined for their psychometric properties and associations with AD risk biomarkers. RESULTS: Composite scores from the novel cognitive and functional measures demonstrated better psychometric properties (distribution and test‐retest reliability) and stronger associations with AD‐related demographic, genetic, and brain risk markers than well‐established measures, DISCUSSION: These novel measures have potential for use as primary cognitive and functional outcomes in early‐stage AD clinical trials. Highlights: Well‐established cognitive tests may not accurately detect subtle cognitive changes.No Practice Effect (NPE) and Computerized Functional Skills Assessment and Training are novel measures designed to have improved psychometric properties.NPE had Executive Function, Cognitive Control/Speed, and Episodic Memory domains.Novel measures had better psychometric properties compared to established measures.Significant associations with Alzheimer's disease biomarkers were found with novel measures. [ABSTRACT FROM AUTHOR]

Objective: In this study, we examine how impairments in vision, hearing, touch, and olfaction relate to depression in older adults, considering both individual and multisensory impairments (MSIs). Study Design: Analysis of cross‐sectional data from a longitudinal investigation involving black and white older adults aged 70 to 79 at enrollment. Setting: We studied 1640 black and white participants in the Health ABC study using complete sensory evaluation data from years 3 to 5. Methods: Our MSI assessment utilized data obtained for visual acuity, hearing perception, olfactory performance, and tactile function. We performed multivariable logistic regression analyses to examine the associations between the presence of individual and MSIs and depression which was defined as the presence of antidepressants prescribed for depression, or a Center for Epidemiological Studies Depression Scale score of greater than 10. Results: We observed a possible dose‐response relationship between the number of sensory impairments and depression. In adjusted models, when compared to no impairments, vision (odds ratio [OR] = 1.45, 95% confidence interval [CI]: 1.09‐1.93) and hearing impairments (OR = 1.49, 95% CI: 1.11‐1.99) were significantly associated with depression, whereas olfaction (OR = 1.11, 95% CI: 0.83‐1.47) and tactile impairments (OR = 1.28, 95% CI: 0.96‐1.70) were not. Participants with 3 sensory impairments had a higher rate of depression (OR = 2.05, 95% CI: 1.22‐3.54) compared to those without impairments, and this risk increased further for those with 4 sensory impairments (OR = 2.95, 95% CI: 1.48‐5.88). Conclusion: The findings suggest that individuals with MSI represent a high‐risk population for depression, warranting close monitoring to screen for depression. The study emphasizes the importance of considering multiple sensory impairments in the context of mental health and supports the early identification and monitoring of depression in this population. [ABSTRACT FROM AUTHOR]

Unexpected lucidity is a phenomenon of scientific, clinical, and psychological relevance to health professionals, to those who experience it, and their relatives. This paper describes qualitative methods used to develop an informant-based measure of lucidity episodes. The approach was refinement of the operationalization of the construct; review of seminal items, modification, and purification; and confirmation of the feasibility of reporting methodology. Modified focus groups were conducted with 20 staff and 10 family members using a web-based survey. Themes included reaction when hearing the term; words that come to mind; description of and first reaction to referenced or observed 'lucidity' events. Semi-structured cognitive interviews were conducted with 10 health professionals working with older adults with cognitive impairment. Data were extracted from Qualtrics or Microsoft 365 Word® for analysis using NVivo. Conceptual issues, as well as issues regarding comprehension, interpretation, clarity, semantics, and standardization of definitions derived from an external advisory board, focus groups and cognitive interviews informed items' modification, and resulted in the final lucidity measure. An obstacle to understanding the mechanisms and estimating the prevalence of lucid events among individuals with dementia and other neurological conditions is the scarcity of reliable and valid measures. The substantive and varied data gathered from multiple methods including the collaborative work of an External Advisory Board, modified focus groups with staff and family caregivers, and structured cognitive interviews with health professionals were central in creating the revised version of the lucidity measure. [ABSTRACT FROM AUTHOR]

Background: There is ample evidence in animal models that lithium increases Brain‐Derived Neurotrophic Factor (BDNF) with supporting evidence in human studies. Little is known, however, about the effects of lithium on BDNF in Alzheimer's Dementia (AD). In one study of patients with Mild Cognitive Impairment, serum BDNF increased after treatment with lithium. These patients also showed mild improvement in cognitive function. Objectives: To evaluate low‐dose lithium treatment of agitation in Alzheimer's disease (AD). Method: We measured levels of BDNF in patients treated with lithium prior to and after a 12‐week randomized placebo‐controlled trial. Results: BDNF levels did not change significantly and were not associated with improvement in overall neuropsychiatric symptoms or in cognitive function. Conclusions: More research is needed to understand the potential effects of lithium on BDNF in AD including whether its use might be dependent on the stage of cognitive decline and dementia. Key points: Lithium is known to increase Brain‐Derived Neurotrophic Factor (BDNF) levels.BDNF has neuroprotective properties.Decreased levels of BDNF have been found in the brains of people with AD.Little is known about the association between the effects of Lithium on BDNF in patients with AD. [ABSTRACT FROM AUTHOR]

Background: The positron emission tomography (PET) radiotracer [18F]MK‐6240 exhibits high specificity for neurofibrillary tangles (NFTs) of tau protein in Alzheimer's disease (AD), high sensitivity to medial temporal and neocortical NFTs, and low within‐brain background. Objectives were to develop and validate a reproducible, clinically relevant visual read method supporting [18F]MK‐6240 use to identify and stage AD subjects versus non‐AD and controls. Methods: Five expert readers used their own methods to assess 30 scans of mixed diagnosis (47% cognitively normal, 23% mild cognitive impairment, 20% AD, 10% traumatic brain injury) and provided input regarding regional and global positivity, features influencing assessment, confidence, practicality, and clinical relevance. Inter‐reader agreement and concordance with quantitative values were evaluated to confirm that regions could be read reliably. Guided by input regarding clinical applicability and practicality, read classifications were defined. The readers read the scans using the new classifications, establishing by majority agreement a gold standard read for those scans. Two naïve readers were trained and read the 30‐scan set, providing initial validation. Inter‐rater agreement was further tested by two trained independent readers in 131 scans. One of these readers used the same method to read a full, diverse database of 1842 scans; relationships between read classification, clinical diagnosis, and amyloid status as available were assessed. Results: Four visual read classifications were determined: no uptake, medial temporal lobe (MTL) only, MTL and neocortical uptake, and uptake outside MTL. Inter‐rater kappas were 1.0 for the naïve readers gold standard scans read and 0.98 for the independent readers 131‐scan read. All scans in the full database could be classified; classification frequencies were concordant with NFT histopathology literature. Discussion: This four‐class [18F]MK‐6240 visual read method captures the presence of medial temporal signal, neocortical expansion associated with disease progression, and atypical distributions that may reflect different phenotypes. The method demonstrates excellent trainability, reproducibility, and clinical relevance supporting clinical use. Highlights: A visual read method has been developed for [18F]MK‐6240 tau positron emission tomography.The method is readily trainable and reproducible, with inter‐rater kappas of 0.98.The read method has been applied to a diverse set of 1842 [18F]MK‐6240 scans.All scans from a spectrum of disease states and acquisitions could be classified.Read classifications are consistent with histopathological neurofibrillary tangle staging literature. [ABSTRACT FROM AUTHOR]

In this review, we comprehensively, qualitatively, and critically synthesized several features of APOE-e2, a known APOE protective variant, including its associations with longevity, cognition, and neuroimaging, and neuropathology, all in humans. If e2's protective effects--and their limits--could be elucidated, it could offer therapeutic windows for Alzheimer's disease (AD) prevention or amelioration. Literature examining e2 within the years 1994-2021 were considered for this review. Studies on human subjects were selectively reviewed and were excluded if observation of e2 was not specified. Effects of e2 were compared with e3 and e4, separately and as a combined non-e2 group. Our examination of existing literature indicated that the most robust protective role of e2 is in longevity and AD neuropathologies, but e2's effect on cognition and other AD imaging markers (brain structure, function, and metabolism) were inconsistent, thus inconclusive. Notably, e2 was associated with greater risk of non-AD proteinopathies and a disadvantageous cerebrovascular profile. We identified multiple methodological shortcomings of the literature on brain function and cognition that could have contributed to inconsistent and potentially misleading findings. We make careful interpretations of existing findings and provide directions for research strategies that could effectively examine the independent and unbiased effect of e2 on AD risk. [ABSTRACT FROM AUTHOR]

Background: The association between sleep and Alzheimer's disease (AD) biomarkers are well-established, but little is known about how they interact to change the course of AD.Objective: To determine the potential interaction between sleep disturbance and Aβ, tau, and APOE4 on brain atrophy and cognitive decline.Methods: Sample included 351 participants (mean age 72.01 ± 6.67, 50.4%female) who were followed for approximately 5 years as part of the Alzheimer's Disease Neuroimaging Initiative. Informant-reported sleep disturbance (IRSD) was measured using the Neuropsychiatric Inventory (NPI). Changes in magnetic resonance imaging (MRI)-measured AD signature brain regions and cognitive performance and IRSD's interaction with cerebrospinal fluid amyloid-β (Aβ42) and p-Tau depositions and APOE4 status were examined using the linear mixed models.Results: Baseline IRSD was not significantly associated with the rate of atrophy after adjusting for covariates (age, sex, education, total NPI severity score, and sleep medications). However, there was a significant interaction between IRSD and AD biomarkers on faster atrophy rates in multiple brain regions, including the cortical and middle temporal volumes. Post-hoc analyses indicated that Aβ and p-Tau/Aβ predicted a faster decline in these regions/domains in IRSD, compared with biomarker-negative individuals with IRSD (ps≤0.001). There was a significant IRSD*APOE4 interaction for brain atrophy rate (ps≤0.02) but not for cognition.Conclusion: IRSD may increase the future risk of AD by contributing to faster brain atrophy and cognitive decline when combined with the presence of AD biomarkers and APOE4. Early intervention for sleep disturbance could help reduce the risk of developing AD. [ABSTRACT FROM AUTHOR]

Objective: Social isolation and emotional isolation, i.e. loneliness, have been associated with dementia or cognitive decline. In contrast, the relationship of restriction of physical and instrumental activities of daily living to cognitive decline and dementia has been less studied.Design: We examined multiple quality of life (QoL) indicators, including isolation and restriction of activities, utilizing two validated scales in elders without dementia to determine their associations with cognitive decline and incident dementia that were followed longitudinally over 6 years. We comprehensively controlled for other symptom constellations, including depression and anergia.Setting: A large multi-ethnic prospective study was conducted in northern Manhattan, NYC.Participants: An ethnically diverse sample of 855 non-demented individuals at baseline participated.Measures: The following QoL scales were utilized: Restriction, Anergia, Isolation, Loneliness, and Affective Suffering.Results: Both Restriction (HR = 2.22, 95% CI [1.42, 3.47], P < .001) and Isolation (HR = 1.78, 95% CI [1.17, 2.70], P = 0.007) were associated with episodic memory and incident dementia, controlling for age, sex, and education. Loneliness and Affective Suffering (depression) were not associated with these outcomes (P's > .1) with both Restriction and Isolation in the same model for the prediction of dementia, only Restriction remained significant (HR = 1.97, 95% CI [1.24, 3.14], P = 0.004). In cross-lagged panel analyses, Restriction and Isolation had reciprocal influences (P's < .001), indicating that Restriction at the previous time point influenced current Isolation. Importantly, Restriction (but not Isolation) and Selective Reminding total recall memory demonstrated highly significant direct and reciprocal influences over time (P's < .001).Conclusions: Restriction and Isolation were associated with incident dementia. Restriction played a more prominent role in its impact on memory decline. The development of these impairments in QoL, particularly Restriction, may provide warning signs of future cognitive decline and dementia and provide multiple and novel avenues for therapeutic interventions with the goal of delaying the development of cognitive decline and dementia. [ABSTRACT FROM AUTHOR]

Introduction: We evaluated impaired odor identification and global cognition as simple, cost-effective alternatives to neuroimaging biomarkers to predict cognitive decline and dementia in the Mayo Clinic Study of Aging., Methods: Six hundred forty-seven participants (mean 8.1, standard deviation 3.4 years' follow-up) had the following baseline procedures: modified Blessed Information Memory Concentration Test (BIMCT), 12-item Brief Smell Identification Test (BSIT), structural brain magnetic resonance imaging (MRI), and positron emission tomography (PET) imaging with 11C-Pittsburgh compound B (11C-PiB) and fluorodeoxyglucose (FDG; subset)., Results: Cognitive decline developed in 102 participants and dementia in 34 participants. In survival analyses, PiB PET showed robust prediction for cognitive decline. Impaired BSIT, impaired BIMCT, MRI, and FDG measures were also significant predictors. The combination of demographics + BSIT + BIMCT showed strong predictive utility (C-index 0.81), similar to demographics + PiB PET (C-index 0.80). Similar but stronger results were obtained for prediction of dementia., Discussion: Impairment in both odor identification test and global cognition was comparable to PiB PET for predicting cognitive decline and dementia., Highlights: In 647 participants in the population-based Mayo Clinic Study of Aging, several clinical markers and biomarkers each predicted cognitive decline or dementia during an average 8 years of follow-up. The combination of the demographic variables of age, sex, and education with a brief odor identification test (BSIT) and a global cognitive test (Blessed Information Memory Concentration Test) showed strong predictive utility (C-index 0.81) for cognitive decline that was similar to the demographic variables combined with Pittsburgh Compound B amyloid imaging (C-index 0.80). Combining a brief odor identification test with a brief cognitive test needs consideration as a simple, cost-effective option in the clinical assessment of individuals at risk of cognitive decline and dementia, as well as a potential tool to identify individuals who may benefit from disease-modifying treatments and to screen participants for prevention trials., (© 2024 The Author(s). Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

Introduction: This study derived composite scores for two novel cognitive measures, the No Practice Effect (NPE) battery and the Miami Computerized Functional Skills Assessment and Training system for use in early-stage Alzheimer's disease (AD) clinical trials. Their psychometric properties and associations with AD risk markers were compared to those of well-established measures., Methods: For 291 older adults with healthy cognition or early mild cognitive impairment, Exploratory factor analyses were used to identify the factor structure of the NPE. Factor and total scores were examined for their psychometric properties and associations with AD risk biomarkers., Results: Composite scores from the novel cognitive and functional measures demonstrated better psychometric properties (distribution and test-retest reliability) and stronger associations with AD-related demographic, genetic, and brain risk markers than well-established measures, DISCUSSION: These novel measures have potential for use as primary cognitive and functional outcomes in early-stage AD clinical trials., Highlights: Well-established cognitive tests may not accurately detect subtle cognitive changes. No Practice Effect (NPE) and Computerized Functional Skills Assessment and Training are novel measures designed to have improved psychometric properties. NPE had Executive Function, Cognitive Control/Speed, and Episodic Memory domains. Novel measures had better psychometric properties compared to established measures. Significant associations with Alzheimer's disease biomarkers were found with novel measures., (© 2024 The Authors. Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)