scholarly journals Alzheimer's disease and sleep disturbances: a review

2019 ◽  
Vol 77 (11) ◽  
pp. 815-824 ◽  
Author(s):  
Conrado Regis Borges ◽  
Dalva Poyares ◽  
Ronaldo Piovezan ◽  
Ricardo Nitrini ◽  
Sonia Brucki

ABSTRACT The association between Alzheimer's disease (AD) and sleep disturbances has received increasing scientific attention in the last decades. However, little is known about the impact of sleep and its disturbances on the development of preclinical AD stages, such as mild cognitive impairment. This review describes the evolution of knowledge about the potential bidirectional relationships between AD and sleep disturbances exploring recent large prospective studies and meta-analyses and studies of the possible mechanisms through which sleep and the neurodegenerative process could be associated. The review also makes a comprehensive exploration of the sleep characteristics of older people, ranging from cognitively normal individuals, through patients with mild cognitive impairment, up to the those with dementia with AD.

2021 ◽  
Author(s):  
Kat Toups ◽  
Ann Hathaway ◽  
Deborah Gordon ◽  
Henrianna Chung ◽  
Cyrus Raji ◽  
...  

Abstract Importance: Effective therapeutics for Alzheimer's disease and mild cognitive impairment are needed. Objective: To determine whether a precision medicine approach to Alzheimer's disease and mild cognitive impairment, in which potential contributors to cognitive decline are identified and targeted therapeutically, is effective enough in a proof-of-concept trial to warrant a larger, randomized, controlled clinical trial. Rationale: Previous clinical trials for Alzheimer's disease have pre-determined a single treatment modality, such as a drug candidate or therapeutic procedure, that may be unrelated to the primary drivers of the neurodegenerative process. Therefore, increasing data set size to include the potential contributors to cognitive decline for each patient, and addressing the identified potential contributors, may represent a more effective therapeutic strategy. Hypothesis: Alzheimer's disease is a multi-factorial network dysfunction that results from a chronic or repeated insufficiency of support for a neuroplasticity network; thus factors that increase demand — such as infections or toxin exposure — or reduce support — such as reduced energetics or trophic support — may contribute to the neurodegenerative process. Rectifying this hypothesized network dysfunction represents a rational approach to the treatment of the cognitive decline associated with Alzheimer's disease and mild cognitive impairment. Design: Twenty-five patients with Alzheimer's disease or mild cognitive impairment, with Montreal Cognitive Assessment (MoCA) scores of 19 or higher, were evaluated for markers of inflammation, chronic infection, dysbiosis, insulin resistance, protein glycation, vascular disease, nocturnal hypoxemia, hormone insufficiency or dysregulation, nutrient deficiency, toxin or toxicant exposure (metals, organic toxicants, and biotoxins), genetic predisposition to cognitive decline, and other biochemical parameters associated with cognitive decline. Brain magnetic resonance imaging with volumetrics was performed at baseline and study conclusion. Patients were treated for nine months with a personalized, precision medicine protocol that addressed each patient's identified potentially contributory factors, and cognition was assessed at t = 0, 3, 6, and 9 months. Trial registration and IRB approval: The clinical trial was registered at clinicaltrials.gov (NCT03883633), 1 and approved by the Advarra IRB. Support for the trial: The trial was supported by a grant from the Four Winds Foundation via Evanthea, LLC, and we are grateful to Diana Merriam and Gayle Brown for their interest, discussions, and support. Main Outcome Measures: Trained external raters evaluated the study subjects with the Montreal Cognitive Assessment (MoCA), CNS Vital Signs (a computerized cognitive assessment battery), AQ-21 (a subjective scale completed by the significant other or study partner), and AQ-C change scale (a subjective scale of cognitive improvement or decline, completed by the significant other or study partner). Follow-up brain MRI with volumetrics was carried out at the completion of the trial. Results: All outcome measures revealed improvement: statistically highly significant improvement in MoCA scores, CNS Vital Signs Neurocognitive Index, and AQ-C were documented. No serious adverse events were recorded. Conclusions and Relevance: Based on the cognitive improvements observed in this study of patients with Alzheimer's disease or mild cognitive impairment, a larger, randomized, controlled trial of the precision medicine therapeutic approach described herein is warranted.


2020 ◽  
Author(s):  
Ruaridh Clark ◽  
Niia Nikolova ◽  
William J. McGeown ◽  
Malcolm Macdonald

AbstractEigenvector alignment, introduced herein to investigate human brain functional networks, is adapted from methods developed to detect influential nodes and communities in networked systems. It is used to identify differences in the brain networks of subjects with Alzheimer’s disease (AD), amnestic Mild Cognitive Impairment (aMCI) and healthy controls (HC). Well-established methods exist for analysing connectivity networks composed of brain regions, including the widespread use of centrality metrics such as eigenvector centrality. However, these metrics provide only limited information on the relationship between regions, with this understanding often sought by comparing the strength of pairwise functional connectivity. Our holistic approach, eigenvector alignment, considers the impact of all functional connectivity changes before assessing the strength of the functional relationship, i.e. alignment, between any two regions. This is achieved by comparing the placement of regions in a Euclidean space defined by the network’s dominant eigenvectors. Eigenvector alignment recognises the strength of bilateral connectivity in cortical areas of healthy control subjects, but also reveals degradation of this commissural system in those with AD. Surprisingly little structural change is detected for key regions in the Default Mode Network, despite significant declines in the functional connectivity of these regions. In contrast, regions in the auditory cortex display significant alignment changes that begin in aMCI and are the most prominent structural changes for those with AD. Alignment differences between aMCI and AD subjects are detected, including notable changes to the hippocampal regions. These findings suggest eigenvector alignment can play a complementary role, alongside established network analytic approaches, to capture how the brain’s functional networks develop and adapt when challenged by disease processes such as AD.


2001 ◽  
Vol 13 (4) ◽  
pp. 411-423 ◽  
Author(s):  
Pieter Jelle Visser ◽  
Frans R. J. Verhey ◽  
Rudolf W. H. M. Ponds ◽  
Jellemer Jolles

Introduction. The aim of the study was to investigate whether the preclinical stage of Alzheimer's disease (AD) can be diagnosed in a clinical setting. To this end we investigated whether subjects with preclinical AD could be differentiated from subjects with nonprogressive mild cognitive impairment and from subjects with very mild AD-type dementia. Methods. Twenty-three subjects with preclinical AD, 44 subjects with nonprogressive mild cognitive impairment, and 25 subjects with very mild AD-type dementia were selected from a memory clinic population. Variables that were used to differentiate the groups were demographic variables, the Mini-Mental State Examination score, performance on cognitive tests, measures of functional impairment, and measures of noncognitive symptomatology. Results. Age and the scores for the delayed recall task could best discriminate between subjects with preclinical AD and subjects with nonprogressive mild cognitive impairment. The overall accuracy was 87% The score on the Global Deterioration Scale and a measure of intelligence could best discriminate between subjects with preclinical AD and subjects with very mild AD-type dementia. The overall accuracy was 85% Conclusions. Subjects with preclinical AD can be distinguished from subjects with nonprogressive mild cognitive impairment and from subjects with very mild AD-type dementia. This means that preclinical AD is a diagnostic entity for which clinical criteria should be developed.


2018 ◽  
Vol 108 (4) ◽  
pp. 354-364 ◽  
Author(s):  
Eduardo Spinedi ◽  
Daniel P. Cardinali

Alzheimer’s disease (AD) is associated with altered eating behavior and metabolic disruption. Amyloid plaques and neurofilament tangles are observed in many hypothalamic nuclei from AD brains. Some of these areas (suprachiasmatic nuclei, lateral hypothalamic area) also play a role in the regulation of the sleep/wake cycle and may explain the comorbidity of eating and sleep disorders observed in AD patients. Inadequate sleep increases the neurodegenerative process, for example, the decrease of slow-wave sleep impairs clearance of β-amyloid peptide (Aβ) and tau protein from cerebral interstitial fluid. Cerebrospinal fluid (CSF) melatonin levels decrease even in preclinical stages (Braak-1 stage) when patients manifest no cognitive impairment, suggesting that reduction of melatonin in CSF may be an early marker (the cause for which is still unknown) of oncoming AD. Melatonin administration augments glymphatic clearance of Aβ and reduces generation and deposition of Aβ in transgenic animal models of AD. It may also set up a new equilibrium among hypothalamic feeding signals. While melatonin trials performed in the clinical phase of AD have failed to show or showed only modest positive effects on cognition, in the preclinical stage of dementia (minimal cognitive impairment) the effect of melatonin is demonstrable with significant improvement of sleep and quality of life. In this review, we discuss the main aspects of hypothalamic alterations in AD, the association between interrupted sleep and neurodegeneration, and the possible therapeutic effect of melatonin on these processes.


2011 ◽  
Vol 24 (4) ◽  
pp. 674-681 ◽  
Author(s):  
Cláudia Godinho ◽  
Ana Luiza Camozzato ◽  
Diego Onyszko ◽  
Márcia Lorena Chaves

ABSTRACTBackground: Higher mild cognitive impairment (MCI) prognostic variability has been related to sample characteristics (community-based or specialized clinic) and to diverse operationalization criteria. The aim of the study was to evaluate the trajectory of MCI of Alzheimer type in a population-based elderly cohort in Southern Brazil. We also estimated the risk for the development of probable Alzheimer's disease (AD) in comparison with healthy subjects.Methods: Data were derived from a population-based cohort (the PALA study). MCI outcomes were sub-classified into three categories: conversion, stabilization, and reconversion. The risk of progression to dementia was compared between MCI and normal participants. The analysis was based on 21 MCI subjects and 220 cognitively intact participants (N = 241).Results: Of the 21 MCI subjects, 38% developed dementia, 24% remained stable and 38% improved. The MCI annual conversion rate to AD was 8.5%. MCI was associated with significantly higher risk of conversion to AD (HR = 49.83, p = 0.004), after adjustment for age, education, sex and Mini-Mental State Examination score.Conclusions: Independent of the heterogeneity of the outcomes, MCI of the Alzheimer type participants showed significantly higher risk of developing probable AD, demonstrating the impact of the use of these MCI criteria that emphasize long-term episodic memory impairment.


2021 ◽  
Vol 12 ◽  
Author(s):  
Gwang-Won Kim ◽  
Shin-Eui Park ◽  
Kwangsung Park ◽  
Gwang-Woo Jeong

The donepezil treatment is associated with improved cognitive performance in patients with mild cognitive impairment (MCI), and its clinical effectiveness is well-known. However, the impact of the donepezil treatment on the enhanced white matter connectivity in MCI is still unclear. The purpose of this study was to evaluate the thalamo-cortical white matter (WM) connectivity and cortical thickness and gray matter (GM) volume changes in the cortical regions following donepezil treatment in patients with MCI using probabilistic tractography and voxel-based morphometry. Patients with MCI underwent magnetic resonance examinations before and after 6-month donepezil treatment. Compared with healthy controls, patients with MCI showed decreased WM connectivity of the thalamo-lateral prefrontal cortex, as well as reduced thickness in the medial/lateral orbitofrontal cortices (p < 0.05). The thalamo-lateral temporal cortex connectivity in patients with MCI was negatively correlated with Alzheimer's disease assessment scale-cognitive subscale (ADAS-cog) (r = −0.76, p = 0.01). The average score of the Korean version of the mini-mental state examination (K-MMSE) in patients with MCI was improved by 7.9% after 6-months of donepezil treatment. However, the patterns of WM connectivity and brain volume change in untreated and treated patients were not significantly different from each other, resulting from multiple comparison corrections. These findings will be valuable in understanding the neurophysiopathological mechanism on MCI as a prodromal phase of Alzheimer's disease in connection with brain functional connectivity and morphometric change.


2009 ◽  
Vol 24 (12) ◽  
pp. 1335-1342 ◽  
Author(s):  
Deidre J. Devier ◽  
Gregory H. Pelton ◽  
Matthias H. Tabert ◽  
Xinhua Liu ◽  
Katrina Cuasay ◽  
...  

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