scholarly journals Neuroendocrine-Metabolic Dysfunction and Sleep Disturbances in Neurodegenerative Disorders: Focus on Alzheimer’s Disease and Melatonin

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.

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.


2017 ◽  
Vol 25 (2) ◽  
pp. 67-79 ◽  
Author(s):  
Maria Cotelli ◽  
Rosa Manenti ◽  
Michela Brambilla ◽  
Elena Gobbi ◽  
Clarissa Ferrari ◽  
...  

Introduction Given the limited effectiveness of pharmacological treatments, non-pharmacological interventions in neurodegenerative diseases have gained increasing attention in recent years and telerehabilitation has been proposed as a cognitive rehabilitation strategy. The purpose of this systematic review is to examine the evidence for the efficacy of cognitive telerehabilitation interventions compared with face-to-face rehabilitation in patients with mild cognitive impairment, Alzheimer’s disease and frontotemporal dementia. Methods In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic search of the Medline database was conducted. Out of 14 articles assessed for eligibility, five studies were identified, three in participants with mild cognitive impairment or Alzheimer’s disease, two in patients with primary progressive aphasia. Results The Physiotherapy Evidence Database scale was used to assess the methodological quality of four out of five studies included in this systematic review, with only one report receiving a high-quality rating. Effect-size analysis evidenced positive effects of telerehabilitation interventions, comparable with those reported for face-to-face rehabilitation. Discussion The available evidence for the effectiveness of cognitive telerehabilitation is limited, and the quality of the evidence needs to be improved. The systematic review provides preliminary evidence suggesting that cognitive telerehabilitation for neurodegenerative disease may have comparable effects as conventional in-person cognitive rehabilitation.


2020 ◽  
pp. jnnp-2020-323870 ◽  
Author(s):  
Che-Sheng Chu ◽  
Cheng-Ta Li ◽  
Andre R. Brunoni ◽  
Fu-Chi Yang ◽  
Ping-Tao Tseng ◽  
...  

ObjectivesTo compare cognitive effects and acceptability of repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) in patients with Alzheimer’s disease (AD) or mild cognitive impairment (MCI), and to determine whether cognitive training (CT) during rTMS or tDCS provides additional benefits.MethodsElectronic search of PubMed, Medline, Embase, the Cochrane Library and PsycINFO up to 5 March 2020. We enrolled double-blind, randomised controlled trials (RCTs). The primary outcomes were acceptability and pre–post treatment changes in general cognition measured by Mini-Mental State Examination, and the secondary outcomes were memory function, verbal fluency, working memory and executive function. Durability of cognitive benefits (1, 2 and ≥3 months) after brain stimulation was examined.ResultsWe included 27 RCTs (n=1070), and the treatment components included high-frequency rTMS (HFrTMS) and low-frequency rTMS, anodal tDCS (atDCS) and cathodal tDCS (ctDCS), CT, sham CT and sham brain stimulation. Risk of bias of evidence in each domain was low (range: 0%–11.1%). HFrTMS (1.08, 9, 0.35–1.80) and atDCS (0.56, 0.03–1.09) had short-term positive effects on general cognition. CT might be associated with negative effects on general cognition (−0.79, –2.06 to 0.48) during rTMS or tDCS. At 1-month follow-up, HFrTMS (1.65, 0.77–2.54) and ctDCS (2.57, 0.20–4.95) exhibited larger therapeutic responses. Separate analysis of populations with pure AD and MCI revealed positive effects only in individuals with AD. rTMS and tDCS were well tolerated.ConclusionsHFrTMS is more effective than atDCS for improving global cognition, and patients with AD may have better responses to rTMS and tDCS than MCI.


Author(s):  
Josue CRUZ-RODRÍGUEZ ◽  
Gabriel BETANZOS-CABRERA ◽  
Brenda Hildeliza CAMACHO-DÍAZ ◽  
María Araceli ORTIZ-RODRÍGUEZ

This review aims to provide scientific evidence of the role of oxidative stress in the development of cognitive impairment and its progression to Alzheimer's disease. Oxidative stress originates when there is an uncontrolled production of free radicals that disrupts the balance between oxidants and antioxidants, favoring oxidants. It has been associated with oxidative stress with the pathogenesis of brain aging, cognitive impairment and some neurological diseases. The cells of the central nervous system produce a high amount of free radicals since their energy demand is high, this coupled with a low antioxidant capacity, favors the appearance of a pro-oxidant environment that contributes to neurodegeneration and neuronal death. Alzheimer's disease is the most frequent form of dementia, it is characterized by neurodegenerative changes that occur with cognitive impairment, progressive impairment of memory and thought, until preventing the performance of daily life activities. Neuropathologically, it is characterized by the presence of extracellular deposits of β-amyloid peptide in the form of neurofibrillar plaques and clews; lesions capable of generating damage and neuronal death that lead to cognitive failure through the generation of more free radicals


2021 ◽  
Vol 13 ◽  
Author(s):  
Ping-Hsuan Wei ◽  
Haifeng Chen ◽  
Qing Ye ◽  
Hui Zhao ◽  
Yun Xu ◽  
...  

Background: Normal establishment of cognition occurs after forming a sensation to stimuli from internal or external cues, in which self-reference processing may be partially involved. However, self-reference processing has been less studied in the Alzheimer’s disease (AD) field within the self-reference network (SRN) and has instead been investigated within the default-mode network (DMN). Differences between these networks have been proven in the last decade, while ultra-early diagnoses have increased. Therefore, investigation of the altered pattern of SRN is significantly important, especially in the early stages of AD.Methods: A total of 65 individuals, including 43 with mild cognitive impairment (MCI) and 22 cognitively normal individuals, participated in this study. The SRN, dorsal attention network (DAN), and salience network (SN) were constructed with resting-state functional magnetic resonance imaging (fMRI), and voxel-based analysis of variance (ANOVA) was used to explore significant regions of network interactions. Finally, the correlation between the network interactions and clinical characteristics was analyzed.Results: We discovered four interactions among the three networks, with the SRN showing different distributions in the left and right hemispheres from the DAN and SN and modulated interactions between them. Group differences in the interactions that were impaired in MCI patients indicated that the degree of damage was most severe in the SRN, least severe in the SN, and intermediate in the DAN. The two SRN-related interactions showed positive effects on the executive and memory performances of MCI patients with no overlap with the clinical assessments performed in this study.Conclusion: This study is the first and primary evidence of SRN interactions related to MCI patients’ functional performance. The influence of the SRN in the ultra-early stages of AD is nonnegligible. There are still many unknowns regarding the contribution of the SRN in AD progression, and we strongly recommend future research in this area.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 655-656
Author(s):  
Meina Zhang ◽  
Young-Eun Cho ◽  
Chooza Moon

Abstract Alzheimer's disease (AD) commonly involves neuropsychiatric symptoms (NPS), such as nighttime behaviors (or sleep disturbance), hallucination, delusion, or mood changes. However, it is unclear how NPS and sleep disturbances are correlated with AD biomarkers. The purpose of this analysis was to examine how NPS and nighttime behaviors are associated with AD CSF biomarkers by cognitive status. A total of 1,667 subjects’ (mean age = 69.4 SD=9.3, 48 % (808) were male) data from the National Alzheimer’s Disease Coordinating Center (NACC) were used, including subjects with dementia (n = 577), mild cognitive impairment (MCI, n = 363), cognitive impairment but not MCI (n = 47), cognitive impairment due to Alzheimer’s etiology (n= 608), and normal cognition (n = 680). The nighttime symptoms, number, and severity of NPS were assessed using the Neuropsychiatric Inventory Questionnaire Quick Version (NPI-Q). Cerebrospinal fluid (CSF) samples were analyzed for Aβ42,dft5 t-tau, p-tau. We used generalized linear models to explore the associations accounting for age, sex, APOE4 alleles, and BMI. We found the number of NPS were associated with Aβ42 (p = 0.042) in individuals with MCI, impaired, or dementia due to Alzheimer’s etiology. Yet, the number of NPS were not associated with t-tau or p-tau in individuals with and without dementia. The severity of NPS including nighttime symptoms were not associated with biomarkers. Our results could suggest that the number of NPS can be reflected by higher CSF Aβ42 levels in the individuals with Alzheimer’s etiology. Future longitudinal analyses are warranted to understand the causal relationships.


GeroScience ◽  
2020 ◽  
Vol 42 (6) ◽  
pp. 1499-1525
Author(s):  
Cecilia Czakó ◽  
Tibor Kovács ◽  
Zoltan Ungvari ◽  
Anna Csiszar ◽  
Andriy Yabluchanskiy ◽  
...  

AbstractCognitive impairment and dementia are major medical, social, and economic public health issues worldwide with significant implications for life quality in older adults. The leading causes are Alzheimer’s disease (AD) and vascular cognitive impairment/dementia (VCID). In both conditions, pathological alterations of the cerebral microcirculation play a critical pathogenic role. Currently, the main pathological biomarkers of AD—β-amyloid peptide and hyperphosphorylated tau proteins—are detected either through cerebrospinal fluid (CSF) or PET examination. Nevertheless, given that they are invasive and expensive procedures, their availability is limited. Being part of the central nervous system, the retina offers a unique and easy method to study both neurodegenerative disorders and cerebral small vessel diseases in vivo. Over the past few decades, a number of novel approaches in retinal imaging have been developed that may allow physicians and researchers to gain insights into the genesis and progression of cerebromicrovascular pathologies. Optical coherence tomography (OCT), OCT angiography, fundus photography, and dynamic vessel analyzer (DVA) are new imaging methods providing quantitative assessment of retinal structural and vascular indicators—such as thickness of the inner retinal layers, retinal vessel density, foveal avascular zone area, tortuosity and fractal dimension of retinal vessels, and microvascular dysfunction—for cognitive impairment and dementia. Should further studies need to be conducted, these retinal alterations may prove to be useful biomarkers for screening and monitoring dementia progression in clinical routine. In this review, we seek to highlight recent findings and current knowledge regarding the application of retinal biomarkers in dementia assessment.


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