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Background: Osteoporosis and Alzheimer's disease are common diseases of aging that would seem to be unrelated, but may be linked through the influence of bone-derived signals on brain function. The aim of the current study is to investigate the relationship between circulating levels of bone-related biomarkers and cognition.Methods: The population included 103 community-dwelling older individuals with memory concerns but without cognitive impairment. A global cognition summary measure was collected at baseline and 6, 12, and 18 months post-enrollment by converting raw scores from 19 cognitive function tests to z-scores and averaging. Baseline plasma concentrations of bone-related biomarkers, including undercarboxylated, carboxylated, and total osteocalcin, parathyroid hormone, C-terminal telopeptide of collagen 1 (CTX-1), procollagen type 1 amino-terminal propeptide, osteoprotegrin, osteopontin, Dickkopf WNT signaling pathway inhibitor 1 (Dkk1), sclerostin, and amyloid β peptides (Aβ40 and Aβ42), were measured.Results: Using sex, age, and education-adjusted mixed-effects models, we found that baseline levels of TNF-related apoptosis-inducing ligand (TRAIL; p < .001), Dkk1 (p = .014), and CTX-1 (p = .046) were related to the annual rate of change of global cognition over the 18 month follow-up. In cognitive domain-specific analysis, baseline TRAIL was found to be positively related to the annual rate of change in episodic (p < .001) and working memory (p = .016), and baseline Dkk1 was positively related to semantic memory (p = .027) and negatively related to working memory (p = .016).Conclusions: These results further confirm the link between bone and brain health and suggest that circulating levels of bone-related biomarkers may have diagnostic potential to predict worsening cognition. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is the most common form of dementia and the prevalence will increase dramatically in the next decades. Although exercise has shown benefits for people with dementia due to AD as well as their caregivers, the impact of a dyadic exercise intervention including both groups as study participants remains to be determined. The authors review the current clinical evidence for dyadic exercise interventions, which are exercise regimens applied to both the person with dementia and the caregiver. A total of 4 controlled trials were reviewed. This review shows that dyadic exercise interventions are feasible and may produce a positive effect on functional independence and caregiver burden. However, there was insufficient evidence to support a benefit of dyadic exercise intervention on cognitive performance and on behavioral and neuropsychiatric symptoms in participants with dementia due to AD. A dyadic exercise intervention improves functional independence and caregiver burden. However, there is a need for well-designed randomized controlled clinical trials to confirm these benefits and to investigate several important points such as the effects of a dyadic exercise intervention on cognitive and noncognitive outcomes of AD, the optimal intensity of exercise training, and the cost effectiveness of such a program. [ABSTRACT FROM AUTHOR]

Introduction Souvenaid® containing Fortasyn® Connect is a medical food designed to support synapse synthesis in persons with Alzheimer's disease (AD). Fortasyn Connect includes precursors (uridine monophosphate; choline; phospholipids; eicosopentaenoic acid; docosahexaenoic acid) and cofactors (vitamins E, C, B12, and B6; folic acid; selenium) for the formation of neuronal membranes. Whether Souvenaid slows cognitive decline in treated persons with mild-to-moderate AD has not been addressed. Methods In a 24-week, double-masked clinical trial at 48 clinical centers, 527 participants taking AD medications [52% women, mean age 76.7 years (Standard Deviation, SD = 8.2), and mean Mini-Mental State Examination score 19.5 (SD = 3.1, range 14-24)] were randomized 1:1 to daily, 125-mL (125 kcal), oral intake of the active product (Souvenaid) or an iso-caloric control. The primary outcome of cognition was assessed by the 11-item Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-cog). Compliance was calculated from daily diary recordings of product intake. Statistical analyses were performed using mixed models for repeated measures. Results Cognitive performance as assessed by ADAS-cog showed decline over time in both control and active study groups, with no significant difference between study groups (difference =0.37 points, Standard Error, SE = 0.57, p = 0.513). No group differences in adverse event rates were found and no clinically relevant differences in blood safety parameters were noted. Overall compliance was high (94.1% [active] and 94.5% [control]), which was confirmed by significant changes in blood (nutritional) biomarkers. Conclusions Add-on intake of Souvenaid during 24 weeks did not slow cognitive decline in persons treated for mild-to-moderate AD. Souvenaid was well tolerated in combination with standard care AD medications. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is a neurodegenerative condition associated with cognitive loss, behavioural changes, functional ability decline and caregiver burden. Given the worldwide public health impact of AD, novel interventions to reduce suffering experienced by AD patients need to be developed. Foods may offer a mechanism for intervention complementary to drugs, devices, biologicals and vaccines. Apart from foods with health claims (including dietary supplements), medical foods are also being explored as an intervention option. The purpose of this article is to describe how medical foods may complement other interventions for AD patients by: (i) defining what a medical food is; (ii) discussing whether AD is a condition amenable to medical food intervention; (iii) reviewing current clinical trial data on medical foods used in participants with AD; and (iv) highlighting steps needed to establish a more comprehensive framework for developing medical foods for AD. While medical foods may be defined differently in other countries, the US Orphan Drug Act of 1998 defined a medical food as a food formulated for enteral intake, taken under physician supervision, and intended to meet the distinctive nutritional requirements identified for a disease or condition. For AD to be amenable to medical food intervention, it must: (i) result in limited or impaired capacity to ingest, digest, absorb or metabolize ordinary food- stuff or certain nutrients; or (ii) have unique, medically determined nutrient requirements; and (iii) require dietary management that cannot be achieved by modification of the normal diet alone. While these criteria are most likely met in advanced AD, identifying unique nutritional requirements in early AD that cannot be met by normal diet modification requires a better under- standing of AD pathophysiology. A PubMed search using the terms 'medical food' and 'Alzheimer', limited to clinical trials published in English with human participants with AD aged >65 years and supplemented by other articles known to meet the inclusion criteria, revealed that only two medical foods, AC-1202 and Souvenaid® with Fortasyn Connect™, have clinical trial results available for discussion. As medical food development for AD is a relatively new endeavour, a window of opportunity exists for all stakeholders to develop a comprehensive framework for assuring that medical food interventions for AD achieve the highest possible scientific and ethical standards to warrant commercialization. [ABSTRACT FROM AUTHOR]

Abstract: Background: Excessive daytime sleepiness (EDS) and nocturnal sleep disruption are common in Alzheimer’s disease (AD). However, little is known regarding risk factors for developing EDS and sleep disruption in AD. In AD, EDS is associated with parkinsonian motor features (PF), which are associated with faster cognitive decline. The primary aim of this exploratory study was to evaluate whether differences in EDS and nocturnal sleep disruption exist between AD participants with versus without PF. Methods: Thirty-six participants with mild AD were evaluated for PF using the modified motor UPDRS (mmUPDRS) scoring system and classified according to absence (AD−PF, n =19) or presence (AD+PF, n =17) of PF. EDS was assessed using questionnaires and a multiple sleep latency test (MSLT) performed the day after nocturnal polysomnogram. Participants were considered “Sleepy” or “Not Sleepy” according to mean MSLT scores (cutoff score=10.4min). Results: Results showed that the AD+PF group were sleepier than the AD−PF group by subjective and objective measures, despite similarities in nocturnal sleep. The AD+PF group had higher scores on the Epworth Sleepiness Scale (8.5 versus 3.9, p =.001). The AD+PF group also had higher percentage of participants that had “Sleepy” MSLT scores compared to the AD−PF group (75% versus 31.6%, respectively; χ 2 =6.56, p =.01). Conclusions: The presence of parkinsonian features may be an independent risk factor for sleepiness in mild AD. [Copyright &y& Elsevier]

Background: Cancer and Alzheimer's disease (AD) are common diseases of aging and share many risk factors. Surprisingly, however, epidemiologic data from several recent independent cohort studies suggest that there may be an inverse association between these diseases.Objective: To determine the relationship between history of cancer and odds of dementia proximate to death and neuropathological indices of AD.Methods: Using data from two separate clinical-pathologic cohort studies of aging and AD, the Religious Orders Study (ROS) and the Rush Memory and Aging Project (MAP), we compared odds of AD dementia proximate to death among participants with and without a history of cancer. We then examined the relation of history of cancer with measures of AD pathology at autopsy, i.e., paired helical filament tau (PHFtau) neurofibrillary tangles and amyloid-β load.Results: Participants reporting a history of cancer had significantly lower odds of AD (OR 0.70 [0.55-0.89], p = 0.0040) proximate to death as compared to participants reporting no prior history of cancer. The results remained significant after adjusting for multiple risk factors including age, sex, race, education, and presence of an APOEɛ4 allele. At autopsy, participants with a history of cancer had significantly fewer PHFtau tangles (p < 0.001) than participants without a history of cancer, but similar levels of amyloid-β.Conclusions: Cancer survivors have reduced odds of developing AD and a lower burden of neurofibrillary tangle deposition. [ABSTRACT FROM AUTHOR]

Background and Objectives Family caregivers will grow in number as dementia prevalence increases, underscoring the continued importance of equipping these individuals for their new roles and ameliorating the adverse effects of caregiving. Research Design and Methods A three-armed, waitlist, randomized trial design tested Tele-Savvy, an online adaptation of a successful in-person psychoeducation program, the Savvy Caregiver. Tele-Savvy is delivered over 43 days to groups of 6–8 caregivers in 7 weekly synchronous sessions accompanied by 36 brief asynchronous video lessons. We enrolled 23 cohorts of 15 eligible caregivers (N = 261), randomized 2:2:1 to active, attention control, and usual care arms. We assessed caregiver psychological well-being and caregiving mastery at baseline and 3, 6, 9, and 12 months. Multilevel linear models assessed outcomes over the 3 time points examined. The trial was slightly truncated, with Data and Safety Monitoring Board approval, because of the apparent confounding psychological effects of coronavirus disease 2019 restrictions. Results Study findings indicate statistically and clinically significant benefits to Tele-Savvy arm caregivers (with moderate to large effect sizes) in the areas of depression, perceived stress, reaction to care recipients' behaviors, and enhancement of caregiver mastery. Expected benefits for caregiver burden and anxiety were not found. Discussion and Implications Findings attest to program efficacy and the viability of employing distance means to improve family caregivers' emotional well-being and sense of mastery in the caregiving role over a 6-month period. Next steps entail finding alternate ways to deliver the program to those with connectivity and/or time constraint problems. [ABSTRACT FROM AUTHOR]

Background: we previously demonstrated that patients with mild Alzheimer's disease and parkinsonian features (AD + PF) are at a higher risk of having daytime sleepiness than mild AD patients without PF (AD − PF).Objective: to determine whether AD + PF patients demonstrate a known a consequence of daytime sleepiness, reduced performance-based sustained attention, compared with AD − PF patients.Methods: a nocturnal polysomnogram and a next-day multiple sleep latency test (MSLT) were performed. Between MSLT nap opportunities, a 10-min psychomotor vigilance test (PVT) was administered and analysed for reciprocal mean response times (IMEAN), number of lapses (LAPSE) and reciprocal mean slowest 10% (ISLOW).Results: a total of 35 patients met criteria (AD + PF, n = 16; AD − PF, n = 19). Comparatively, the AD + PF group had slower IMEAN results [F(1,28) = 6.64, P < 0.05] and higher LAPSE rates [F(1,27) = 7.57, P < 0.05]. ISLOW measures were not different between groups. When accounting for MSLT results, IMEAN and LAPSE results were no longer significantly different between groups during morning tests, but remained significantly different on afternoon tests.Conclusion: PFs in mild AD are associated with decreased sustained attention as measured by the PVT. Sleepiness did not fully account for the impairment in sustained attention, suggesting that the presence of PFs has an independent negative association with sustained attention in mild AD. [ABSTRACT FROM AUTHOR]

Few studies have measured the effect of genetic factors on dementia and cognitive decline in healthy older individuals followed prospectively. We studied cumulative incidence of dementia and cognitive decline, stratified by APOE genotypes and polygenic risk score (PRS) tertiles, in 12,978 participants of the ASPirin in Reducing Events in the Elderly (ASPREE) trial. At enrolment, participants had no history of diagnosed dementia, cardiovascular disease, physical disability or cognitive impairment. Dementia (adjudicated trial endpoint) and cognitive decline, defined as a >1.5 standard deviation decline in test score for either global cognition, episodic memory, language/executive function or psychomotor speed, versus baseline scores. Cumulative incidence for all‐cause dementia and cognitive decline was calculated with mortality as a competing event, stratified by APOE genotypes and tertiles of a PRS based on 23 common non‐APOE variants. During a median 4.5 years of follow‐up, 324 participants developed dementia, 503 died. Cumulative incidence of dementia to age 85 years was 7.4% in all participants, 12.6% in APOE ε3/ε4 and 26.6% in ε4/ε4. APOE ε4 heterozygosity/homozygosity was associated with a 2.5/6.3‐fold increased dementia risk and 1.4/1.8‐fold cognitive decline risk, versus ε3/ε3 (p < 0.001 for both). High PRS tertile was associated with a 1.4‐fold dementia risk versus low (CI 1.04–1.76, p = 0.02), but was not associated with cognitive decline (CI 0.96–1.22, p = 0.18). Incidence of dementia among healthy older individuals is low across all genotypes; however, APOE ε4 and high PRS increase relative risk. APOE ε4 is associated with cognitive decline, but PRS is not. [ABSTRACT FROM AUTHOR]

Objective: To test the hypothesis that Alzheimer's disease and related neuropathologies contribute to the association between hospitalization and cognitive decline in old age.Methods: As part of a longitudinal clinical-pathologic cohort study, 526 older persons (mean age at death = 90.9 years, 71% female) without dementia at baseline completed annual cognitive testing and were autopsied at death. Hospitalization information was obtained from linked Medicare claims records. Neuropathologic examination assessed β-amyloid burden, tau tangle density, neocortical Lewy bodies, hippocampal sclerosis, chronic gross and microscopic cerebral infarcts, and transactive response DNA binding protein 43 kDa.Results: Over a mean of 5.1 years, a total of 1,383 hospitalizations occurred, and the mean annual rate of hospitalization was 0.5 (standard deviation = 0.6, median = 0.4). Higher rate of hospitalization was not directly related to higher burden for any of the neuropathologic markers. Higher rate of hospitalization was associated with more rapid cognitive decline (estimate = -0.042, standard error [SE] = 0.012, p < 0.001), and after controlling for all 7 neuropathologic markers, the association was essentially the same (estimate = -0.040, SE = 0.013, p = 0.002). In a multivariable model with 3-way interactions of neuropathologic markers with hospitalization rate and time, the association between hospitalization rate and faster cognitive decline was greater in persons with more tangle pathology (estimate for interaction = -0.007, SE = 0.002, p = 0.002) and in persons with neocortical Lewy bodies (estimate for interaction = -0.117, SE = 0.042, p = 0.005).Interpretation: Older persons with more hospitalizations experienced faster rates of cognitive decline, and this association was more pronounced in persons with more tau tangle density and with neocortical Lewy body pathologies. ANN NEUROL 2019;86:844-852. [ABSTRACT FROM AUTHOR]

Background: Despite the importance of persons with dementia (PWDs) engaging in advance care planning (ACP) at a time when they are still competent to appoint a surrogate decision maker and meaningfully participate in ACP discussions, studies of ACP in PWDs are rare. Objective: We conducted an intervention development study to adapt an efficacious ACP intervention, SPIRIT (sharing patient's illness representations to increase trust), for PWDs in early stages (recent Montreal Cognitive Assessment [MoCA] score ≥13) and their surrogates and assess whether SPIRIT could help PWDs engage in ACP. Design: A formative expert panel review of the adapted SPIRIT, followed by a randomized trial with qualitative interviews, was conducted. Patient–surrogate dyads were randomized to SPIRIT in person (in a private room in a memory clinic) or SPIRIT remote (via videoconferencing from home). Setting/Subjects: Twenty-three dyads of PWDs and their surrogates were recruited from an outpatient brain health center. Participants completed preparedness outcome measures (dyad congruence on goals of care, patient decisional conflict, and surrogate decision-making confidence) at baseline and two to three days post-intervention, plus a semistructured interview. Levels of articulation of end-of-life wishes of PWDs during SPIRIT sessions were rated (3 = expressed wishes very coherently, 2 = somewhat coherently, and 1 = unable to express coherently). Results: All 23 were able to articulate their end-of-life wishes very or somewhat coherently during the SPIRIT session; of those, 14 PWDs had moderate dementia. While decision-making capacity was higher in PWDs who articulated their wishes very coherently, MoCA scores did not differ by articulation levels. PWDs and surrogates perceived SPIRIT as beneficial, but the preparedness outcomes did not change pre–post. Conclusions: SPIRIT engaged PWDs and surrogates in meaningful ACP discussions, but requires testing of efficacy and long-term outcomes. [ABSTRACT FROM AUTHOR]

People in the early stages of Alzheimer's disease and related dementias (ADRD) are encouraged to engage in advance care planning (ACP) while they are still competent to appoint a surrogate decision maker and meaningfully participate in ACP discussions with the surrogate. In this NIH Stage I behavioral intervention development trial, we will adapt and test an efficacious ACP intervention, SPIRIT (Sharing Patient's Illness Representation to Increase Trust), with people with mild dementia and their surrogates to promote open, honest discussions while such discussions about end-of-life care are possible. We will first adapt SPIRIT (in person) to target people with mild dementia and their surrogates through a process of modification-pretesting-refinement using stakeholders (persons with mild dementia, family caregivers, and clinicians) and experts, including adapting the delivery mode to interactive web-based videoconference format (SPIRIT-remote). Then in a 3-group RCT with 120 patient-surrogate dyads, we will evaluate the feasibility and acceptability of SPIRIT in-person and SPIRIT remote , and preliminary efficacy of SPIRIT compared to usual care on preparedness outcomes for end-of-life decision making (dyad congruence on goals of care, patient decisional conflict, and surrogate decision-making confidence) shortly after the intervention. This Stage I research of SPIRIT will generate valuable insights regarding how to improve ACP for people with mild dementia who will progress to an advanced stage of the disease in the foreseeable future. Trial registration: ClinicalTrials.gov NCT03311711, Registered 10/12/2017 [ABSTRACT FROM AUTHOR]

Objective: Previous gene expression analysis identified a network of coexpressed genes that is associated with β-amyloid neuropathology and cognitive decline in older adults. The current work targeted influential genes in this network with quantitative proteomics to identify potential novel therapeutic targets.Methods: Data came from 834 community-based older persons who were followed annually, died, and underwent brain autopsy. Uniform structured postmortem evaluations assessed the burden of β-amyloid and other common age-related neuropathologies. Selected reaction monitoring quantified cortical protein abundance of 12 genes prioritized from a molecular network of aging human brain that is implicated in Alzheimer's dementia. Regression and linear mixed models examined the protein associations with β-amyloid load and other neuropathological indices as well as cognitive decline over multiple years preceding death.Results: Average age at death was 88.6 years. Overall, 349 participants (41.9%) had Alzheimer's dementia at death. A higher level of PLXNB1 abundance was associated with more β-amyloid load (p = 1.0 × 10-7 ) and higher PHFtau tangle density (p = 2.3 × 10-7 ), and the association of PLXNB1 with cognitive decline is mediated by these known Alzheimer's disease pathologies. On the other hand, higher IGFBP5, HSPB2, and AK4 and lower ITPK1 levels were associated with faster cognitive decline, and, unlike PLXNB1, these associations were not fully explained by common neuropathological indices, suggesting novel mechanisms leading to cognitive decline.Interpretation: Using targeted proteomics, this work identified cortical proteins involved in Alzheimer's dementia and begins to dissect two different molecular pathways: one affecting β-amyloid deposition and another affecting resilience without a known pathological footprint. Ann Neurol 2018;83:78-88. [ABSTRACT FROM AUTHOR]

Background: Souvenaid® (uridine monophosphate, docosahexaenoic acid, eicosapentaenoic acid, choline, phospholipids, folic acid, vitamins B12, B6, C, and E, and selenium), was developed to support the formation and function of neuronal membranes.Objective: To determine effect sizes observed in clinical trials of Souvenaid and to calculate the number needed to treat to show benefit or harm.Methods: Data from all three reported randomized controlled trials of Souvenaid in Alzheimer's disease (AD) dementia (Souvenir I, Souvenir II, and S-Connect) and an open-label extension study were included in analyses of effect size for cognitive, functional, and behavioral outcomes. Effect size was determined by calculating Cohen's d statistic (or Cramér's V method for nominal data), number needed to treat and number needed to harm. Statistical calculations were performed for the intent-to-treat populations.Results: In patients with mild AD, effect sizes were 0.21 (95% confidence intervals: -0.06, 0.49) for the primary outcome in Souvenir II (neuropsychological test battery memory z-score) and 0.20 (0.10, 0.34) for the co-primary outcome of Souvenir I (Wechsler memory scale delayed recall). No effect was shown on cognition in patients with mild-to-moderate AD (S-Connect). The number needed to treat (6 and 21 for Souvenir I and II, respectively) and high number needed to harm values indicate a favorable harm:benefit ratio for Souvenaid versus control in patients with mild AD.Conclusions: The favorable safety profile and impact on outcome measures converge to corroborate the putative mode of action and demonstrate that Souvenaid can achieve clinically detectable effects in patients with early AD. [ABSTRACT FROM AUTHOR]

To assess the value of exosomal miRNAs as biomarkers for Alzheimer disease (AD), the expression of microRNAs was measured in a plasma fraction enriched in exosomes by differential centrifugation, using Illumina deep sequencing. Samples from 35 persons with a clinical diagnosis of AD dementia were compared to 35 age and sex matched controls. Although these samples contained less than 0.1 microgram of total RNA, deep sequencing gave reliable and informative results. Twenty miRNAs showed significant differences in the AD group in initial screening (miR-23b-3p, miR-24-3p, miR-29b-3p, miR-125b-5p, miR-138-5p, miR-139-5p, miR-141-3p, miR-150-5p, miR-152-3p, miR-185-5p, miR-338-3p, miR-342-3p, miR-342-5p, miR-548at-5p, miR-659-5p, miR-3065-5p, miR-3613-3p, miR-3916, miR-4772-3p, miR-5001-3p), many of which satisfied additional biological and statistical criteria, and among which a panel of seven miRNAs were highly informative in a machine learning model for predicting AD status of individual samples with 83–89% accuracy. This performance is not due to over-fitting, because a) we used separate samples for training and testing, and b) similar performance was achieved when tested on technical replicate data. Perhaps the most interesting single miRNA was miR-342-3p, which was a) expressed in the AD group at about 60% of control levels, b) highly correlated with several of the other miRNAs that were significantly down-regulated in AD, and c) was also reported to be down-regulated in AD in two previous studies. The findings warrant replication and follow-up with a larger cohort of patients and controls who have been carefully characterized in terms of cognitive and imaging data, other biomarkers (e.g., CSF amyloid and tau levels) and risk factors (e.g., apoE4 status), and who are sampled repeatedly over time. Integrating miRNA expression data with other data is likely to provide informative and robust biomarkers in Alzheimer disease. [ABSTRACT FROM AUTHOR]

Accumulating evidence shows nutritional factors influence the risk of developing Alzheimer's disease (AD) and its rate of clinical progression. Dietary and lifestyle guidelines to help adults reduce their risk have been developed. However, the clinical dementia picture remains complex, and further evidence is required to demonstrate that modifying nutritional status can protect the brain and prevent, delay, or reduce pathophysiological consequences of AD. Moreover, there is a pressing need for further research because of the global epidemic of overweight and obesity combined with longer life expectancy of the general population and generally observed decreases in body weight with aging and AD. A new research approach is needed, incorporating more sophisticated models to account for complex scenarios influencing the relationship between nutritional status and AD. Systematic research should identify and address evidence gaps. Integrating longitudinal epidemiological data with biomarkers of disease, including brain imaging technology, and randomized controlled interventions may provide greater insights into progressive and subtle neurological changes associated with dietary factors in individuals at risk for or living with AD. In addition, greater understanding of mechanisms involved in nutritional influences on AD risk and progression, such as oxidative stress and loss of neuronal membrane integrity, will better inform possible interventional strategies. There is consensus among the authors that nutritional deficits, and even states of excess, are associated with AD, but more work is needed to determine cause and effect. Appropriately designed diets or nutritional interventions may play a role, but additional research is needed on their clinical-cognitive effectiveness. [ABSTRACT FROM AUTHOR]

Abstract: In addition to atrophy of mesial temporal lobe structures critical for memory function, white matter projections to the hippocampus may be compromised in individuals with mild Alzheimer''s disease (AD), thereby compounding the memory difficulty. In the present study, high-resolution structural imaging and diffusion tensor imaging techniques were used to examine microstructural alterations in the parahippocampal white matter (PWM) region that includes the perforant path. Results demonstrated white matter volume loss bilaterally in the PWM in patients with mild AD. In addition, the remaining white matter had significantly lower fractional anisotropy and higher mean diffusivity values. Both increased mean diffusivity and volume reduction in the PWM were associated with memory performance and ApoE ε4 allele status. These findings indicate that, in addition to partial disconnection of the hippocampus from incoming sensory information due to volume loss in PWM, microstructural alterations in remaining fibers may further degrade impulse transmission to the hippocampus and accentuate memory dysfunction. The results reported here also suggest that ApoE ε4 may exacerbate PWM changes. [Copyright &y& Elsevier]

Background/Aims: Previous functional MRI studies in individuals with amnestic mild cognitive impairment (AMCI), a putative, prodromal form of Alzheimer’s disease, reveal substantial regional changes in brain activation during episodic memory function. Methods: Functional MRI was applied to examine changes in brain activation during different stages of episodic memory function using a subsequent memory task in individuals with AMCI relative to older normal controls. Results: We found that the AMCI group displayed greater activation in the right hippocampus but less activation in the frontal cortex relative to the older normal control group during intentional encoding of items that were subsequently recognized. We observed nearly the opposite pattern of results for successful recognition. The AMCI group displayed less activation in the medial temporal cortex but greater activation in the frontal cortex. In addition, the AMCI group showed reduced activation in the medial temporal and frontal cortices during incidental encoding of novel information during recognition. Conclusion: The results of the present study suggest that brain activation differences in individuals with AMCI are modulated by the stage of episodic memory examined (i.e. intentional vs. incidental encoding vs. recognition). These observations may help to clarify some of the conflicting findings regarding brain activation changes in AMCI. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

The concept of amnestic mild cognitive impairment (MCI) describes older people who show a decline predominantly in memory function, but who do not meet criteria for dementia. Because such individuals are at high risk for developing Alzheimer's disease, they are of great interest for understanding the prodromal stages of the disease process. The mechanism underlying memory dysfunction in people with MCI is not fully understood. The present study uses quantitative, high-resolution structural MRI techniques to investigate, in vivo, the anatomical substrate of memory dysfunction associated with MCI. Changes in brain structures were assessed with two imaging techniques: (i) whole-brain, voxel-based morphometry to determine regions of reduced white matter volume and (ii) sensitive volumetric segmentation of the entorhinal cortex and hippocampus, gray matter regions that are critically important for memory function. In participants with amnestic MCI, compared with age-matched controls, results showed a significant decrease in white matter volume in the region of the parahippocampal gyrus that includes the perforant path. There was also significant atrophy in both the entorhinal cortex and the hippocampus. Regression models demonstrated that both hippocampal volume and parahippocampal white matter volume were significant predictors of declarative memory performance. These results suggest that, in addition to hippocampal atrophy, disruption of parahippocampal white matter fibers contributes to memory decline in elderly individuals with MCI by partially disconnecting the hippocampus from incoming sensory information. [ABSTRACT FROM AUTHOR]

Age is the most robust risk factor for Alzheimer's dementia, however there is little data on the relation of age to Alzheimer's disease (AD) and other common neuropathologies that contribute to Alzheimer's dementia. We use data from two community-based, clinical-pathologic cohorts to examine the association of age with AD and other common pathologies. Participants were 1420 autopsied individuals from the Religious Orders Study or Rush Memory and Aging Project who underwent annual clinical evaluations for diagnosis of Alzheimer's dementia, mild cognitive impairment (MCI), and level of cognition. The neuropathologic traits of interest were pathologic AD according to modified NIA-Reagan criteria, three quantitative measures of AD pathology (global AD pathology score, β-amyloid load and PHFtau tangle density), macro- and micro-scopic infarcts, neocortical Lewy bodies, TDP-43 and hippocampal sclerosis. Semiparametric generalized additive models examined the nonlinear relationship between age and the clinical and pathological outcomes. The probability of Alzheimer's dementia at death increased with age such that for every additional year of age, the log odds of Alzheimer's dementia was 0.067 higher, corresponding to an odds ratio of 1.070 (p < 0.001). Results were similar for cognitive impairment and level of cognition. By contrast, a nonlinear relationship of age with multiple indices of AD pathology was observed (all ps < 0.05), such that pathologic AD reached a peak around 95 years of age and leveled off afterwards; the quantitative measures of AD pathology were significantly lower at ages above 95. The association of age with other neuropathologies was quite distinct from that of AD in that most increased with advancing age. AD pathology appears to peak around 95 years of age while other common pathologies continue to increase with age. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the frequency of fragile X mental retardation 1 ( FMR1 ) premutation size expansions in individuals with Alzheimer's disease (AD) and other cognitive disorders compared with control subjects. FMR1 genetic screening was completed in patients being seen in a neurobehavioral or AD clinics. Appropriate controls were also collected. A second cohort was a community based, autopsy confirmed, sample of individuals with normal cognitive function, mild cognitive impairment, or AD. There was not an increased frequency of FMR1 expansions in individuals with cognitive disorders, including AD, compared with control subjects. [ABSTRACT FROM AUTHOR]