Alzheimers Res Ther
November 2024
Background: The role of Vascular risk factors (VRFs) in the progression of Alzheimer's Disease (AD) and cognitive decline remains to be elucidated, with previous studies resulting in conflicting findings. The possible impact of age-specific mechanisms of resilience/vulnerability is an under addressed issue. We evaluated the association of VRFs with markers of amyloid deposition, neurodegeneration, and blood-brain-barrier (BBB) permeability (Albumin quotient, Qalb), stratifying patients into early-onset (< 65, EOAD), classic late-onset (65-75, cLOAD) and very late-onset (> 75, vLOAD), to evaluate the moderating effect of age of onset.
View Article and Find Full Text PDFLecanemab (Leqembi, Biogen), a humanized anti-amyloid-beta monoclonal antibody, has been approved for early-stage Alzheimer's disease (AD) in several countries, including the US and Japan. However, the European Medicines Agency (EMA) recently issued a negative opinion on its marketing authorization, reflecting concerns over the clinical value and manageability of anti-amyloid treatments. This decision highlights the ongoing disconnect between research advancements and clinical practice, where the focus on biological markers over tangible clinical improvements remains contentious.
View Article and Find Full Text PDFBackground: The neural activity of the Default Mode Network (DMN) is disrupted in patients with In Alzheimer's disease (AD).
Objectives: We used a novel multimodal approach to track neural signal propagation within the DMN in AD patients.
Methods: Twenty mild to moderate AD patients were recruited.
Alzheimer's Disease (AD) is characterized by structural and functional dysfunction involving the Default Mode Network (DMN), for which the Precuneus (PC) is a key node. We proposed a randomized double-blind pilot study to determine neurobiological changes after 24 weeks of PC-rTMS in patients with mild-to-moderate AD. Sixteen patients were randomly assigned to SHAM or PC-rTMS, and received an intensive 2-weeks course with daily rTMS sessions, followed by a maintenance phase in which rTMS has been applied once a week.
View Article and Find Full Text PDFAstrocytes in Alzheimer's disease (AD) exert a pivotal role in the maintenance of blood-brain barrier (BBB) integrity essentially through structural support and release of soluble factors. This study provides new insights into the vascular remodeling processes occurring in AD, and reveals, in vivo, a pathological profile of astrocytic secretion involving Vascular Endothelial Growth Factor (VEGF), Matrix Metalloproteinases (MMP)-9, MMP-2 and Endothelin-1 (ET-1). Cerebrospinal fluid (CSF) levels of VEGF, MMP-2/-9 were lower in patients belonging to the AD continuum, compared to aged-matched controls.
View Article and Find Full Text PDFIntroduction: Inflammation is an important player in Alzheimer's disease (AD), whose effects can be influenced by the blood-brain barrier (BBB). Here, we investigated the relationship between BBB permeability, indicated by cerebrospinal fluid (CSF)/plasma albumin quotient (Qalb), and CSF indexes of neuroinflammation in a cohort of biologically defined AD patients.
Methods: Fifty-nine consecutive patients with mild cognitive impairment (MCI) or early AD (Mini-Mental State Examination [MMSE] >22) underwent CSF analysis for inflammatory cytokines (interleukin [IL]-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, Il-10, IL-12, IL-13, IL-17, tumor necrosis factor-α [TNF-α], interferon-γ [IFN-γ], granulocyte-monocyte colony-stimulating factor [GM-CSF], granulocyte colony-stimulating factor [G-CSF]).
Background: Gamma (γ) brain oscillations are dysregulated in Alzheimer's disease (AD) and can be modulated using transcranial alternating stimulation (tACS). In the present paper, we describe the rationale and design of a study assessing safety, feasibility, clinical and biological efficacy, and predictors of outcome of a home-based intervention consisting of γ-tACS over the precuneus.
Methods: In a first phase, 60 AD patients will be randomized into two arms: ARM1, 8-week precuneus γ-tACS (frequency: 40 Hz, intensity: 2 mA, duration: 5 60-min sessions/week); and ARM2, 8-week sham tACS (same parameters as the real γ-tACS, with the current being discontinued 5 s after the beginning of the stimulation).
Alzheimers Res Ther
August 2023
Background: Despite the high sensitivity of cerebrospinal fluid (CSF) amyloid beta (Aβ) to detect amyloid pathology, the Aβ/Aβ ratio (amyR) better estimates amyloid load, with higher specificity for Alzheimer's disease (AD). However, whether Aβ and amyR have different meanings and whether Aβ represents more than an Aβ-corrective factor remain to be clarified. Our study aimed to compare the ability of Aβ and amyR to detect AD pathology in terms of p-tau/Aβ ratio and brain glucose metabolic patterns using fluorodeoxyglucose-positron emission tomography (FDG-PET).
View Article and Find Full Text PDFGlial and microglial cells contribute to brain glucose consumption and could actively participate in shaping patterns of brain hypometabolism. Here, we aimed to investigate the association between F-fluorodeoxyglucose (F-FDG) uptake and markers of microglial and astrocytic activity in a cohort of patients with Alzheimer's Disease (AD). We dosed cerebrospinal fluid (CSF) levels of soluble Triggering Receptor Expressed on Myeloid cells (sTREM2), Glial Fibrillary Acidic Protein (GFAP), a marker of reactive astrogliosis, and β-S100, a calcium-binding protein associated with a neurotoxic astrocytic profile.
View Article and Find Full Text PDFJ Alzheimers Dis
April 2023
Background: Many transversal mechanisms act synergistically at different time-points in the cascade of Alzheimer's disease (AD), since amyloid-β (Aβ) deposition, tau pathology, and neuroinflammation influence each other.
Objective: We explored the contributions of microglia and astrocytes in patients with symptomatic sporadic AD stratified according to AT(N) system and APOE genotype.
Methods: We compared the cerebrospinal fluid (CSF) levels of sTREM-2 and markers of astrocytic activation (GFAP; β-S100) from 71 patients with AD (23 A+T-,48 A+T+; 38 APOEɛ3, 33 APOEɛ4) and 30 healthy controls (HC).
Background And Purpose: The locus coeruleus (LC) provides dopamine/noradrenaline (DA/NA) innervation throughout the brain and undergoes early degeneration in Alzheimer's disease (AD). We evaluated catecholaminergic enzyme levels in the cerebrospinal fluid (CSF) of a group of patients biologically defined as within the AD continuum (ADc) and explored their relationship with AD biomarkers and cytokine/growth factor levels to investigate their interplay with neurodegenerative and neuroinflammatory processes.
Methods: The CSF concentration of DA transporter (DAT), tyrosine-hydroxylase (TH), DOPA-decarboxylase (DDC), and dopamine-β-hydroxylase (DβH), as well as cytokine/growth factor levels, were analyzed in 41 ADc patients stratified according to CSF beta-amyloid (Aβ) (A) and p-tau (T) in AD pathological changes (A+ T-) and AD (A+ T+) subgroups, as well as in 15 control subjects (A- T-).
Objective: The aim of our study was to evaluate the diagnostic and prognostic value of Electroencephalogram (EEG), brain Magnetic Resonance Imaging (MRI) and cerebrospinal fluid features, currently representing Creutzfeldt-Jacob Disease (CJD) diagnostic criteria.
Methods: A retrospective study on rapidly progressive dementia patients admitted at the Neurology Clinic of the University of Rome "Tor Vergata" between 2015 and 2020 was conducted. We evaluated clinical, EEG, cerebrospinal fluid and neuroradiological findings.
Objective: Neuronal excitation/inhibition (E/I) imbalance is a potential cause of neuronal network malfunctioning in Alzheimer's disease (AD), contributing to cognitive dysfunction. Here, we used a novel approach combining transcranial magnetic stimulation (TMS) and electroencephalography (EEG) to probe cortical excitability in different brain areas known to be directly involved in AD pathology.
Methods: We performed TMS-EEG recordings targeting the left dorsolateral prefrontal cortex (l-DLPFC), the left posterior parietal cortex (l-PPC), and the precuneus (PC) in a large sample of patients with mild-to-moderate AD (n = 65) that were compared with a group of age-matched healthy controls (n = 21).
Increasing evidence strongly supports the key role of neuroinflammation in the pathophysiology of neurodegenerative diseases, such as Alzheimer's disease, frontotemporal dementia, and amyotrophic lateral sclerosis. Neuroinflammation may alter synaptic transmission contributing to the progression of neurodegeneration, as largely documented in animal models and in patients' studies. In the last few years, palmitoylethanolamide (PEA), an endogenous lipid mediator, and its new composite, which is a formulation constituted of PEA and the well-recognized antioxidant flavonoid luteolin (Lut) subjected to an ultra-micronization process (co-ultraPEALut), has been identified as a potential therapeutic agent in different disorders by exerting potential beneficial effects on neurodegeneration and neuroinflammation by modulating synaptic transmission.
View Article and Find Full Text PDFObjective: In Alzheimer disease (AD) animal models, synaptic dysfunction has recently been linked to a disorder of high-frequency neuronal activity. In patients, a clear relation between AD and oscillatory activity remains elusive. Here, we attempt to shed light on this relation by using a novel approach combining transcranial magnetic stimulation and electroencephalography (TMS-EEG) to probe oscillatory activity in specific hubs of the frontoparietal network in a sample of 60 mild-to-moderate AD patients.
View Article and Find Full Text PDFIntroduction: Frontotemporal dementia (FTD) is a neurodegenerative disorder for which there is no effective pharmacological treatment. Recently, interneuron activity responsible for fast oscillatory brain activity has been found to be impaired in a mouse model of FTD with consequent cognitive and behavioral alterations. In this study, we aim to investigate the safety, tolerability, and efficacy of a novel promising therapeutic intervention for FTD based on 40 Hz transcranial alternating current stimulation (tACS), a form of non-invasive brain stimulation thought to engage neural activity in a frequency-specific manner and thus suited to restore altered brain oscillatory patterns.
View Article and Find Full Text PDFBackground: Long-term potentiation (LTP) like-cortical plasticity impairment and cholinergic neurotransmission deficits have been widely demonstrated in Alzheimer's disease (AD) patients.
Objective: In this study we aim to investigate the neurophysiological features underlying cognitive decline in AD patients according to the National Institute on Aging-Alzheimer's Association (NIA-AA) classification and APOE genotype.
Methods: 65 newly diagnosed AD patients were enrolled.
Brain Res Bull
November 2021
The cholinergic neurotransmitter system in the brain is crucial in processing information related to cognitive, behavioral, and motor functions. A cholinergic dysfunction has been correctly described as one of the primary causes of neurodegenerative diseases. Differences in levels of acetylcholine or expression and function of receptors in selected brain areas have been indicated as one of the causes of sexual dimorphism in neurotransmission.
View Article and Find Full Text PDFBackground And Purpose: Diabetes mellitus (DM) is considered a risk factor for Alzheimer's disease (AD) and shares some pathological pathways, such as activation of amyloid cascade and tau phosphorylation. The aim of the present study was to investigate to what extent DM could impact on neurodegeneration within the AD continuum, using β amyloid (A: Aβ ) and phosphorylated tau (T: p-tau) biomarkers to discriminate patients by Alzheimer's pathological change (A+/T-) and AD (A+/T+), according to the National Institute on Aging and Alzheimer's Association classification. In addition, we aimed to evaluate whether APOE genotype interacts with tau protein and glucose metabolism dysfunction to affect the pathological process.
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