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BACKGROUND: The development of effective strategies to maintain good mental health of older adults is a public health priority. Mindfulness-based interventions have the potential to improve psychological well-being and cognitive functions of older adults, but little is known about the effect of such interventions when delivered through internet. During the COVID-19 pandemic we evaluated short- and long-term cognitive, psychological, and physiological effects of a mindfulness-based intervention (MBI) delivered via web-based videoconference in healthy older adults. METHODS: Fifty older adults participated in an 8-week MBI, which comprised structured 2-h weekly group sessions. A comprehensive evaluation encompassing cognitive (verbal memory, attention and processing speed, executive functions) and psychological assessments (depression and anxiety symptoms, mindfulness, worries, emotion regulation strategies, well-being, interoceptive awareness and sleep) was conducted. Additionally, electroencephalography (EEG) data were recorded before and after the MBI and at the 6-month follow-up (T6). Data were analyzed using an intention-to-treat approach, using linear mixed models adjusted for age. The effect size for time was computed as omega squared. RESULTS: We observed significant improvements from pre-MBI to post-MBI and at the T6 across several measures. These improvements were notable in the areas of verbal memory (California Verbal Learning Test, p ≤ .007), attention and executive functions (Trail Making Test A and BA, p < .050), interoceptive awareness (Multidimensional Assessment of Interoceptive Awareness, p = .0002 for self-regulation and p < .05 for noticing, body listening, and trusting dimensions), and rumination (Heidelberg Form for Emotion Regulation Strategies, p = .018). These changes were associated with low to medium effect size. Moreover, we observed significant changes in EEG patterns, with a decrease in alpha1 (p = .004) and an increase in alpha2 (p < .0001) from pre-MBI to T6. Notably, improvements in TMTBA and rumination were correlated with the decrease in alpha1 (p < .050), while improvements in TMTA were linked to the increase in alpha2 (p = .025). CONCLUSIONS: The results of our study show that a web-based MBI in older adults leads to improvements in cognitive and psychological measures, with associated modulations in specific brain rhythms. While these findings are promising, further controlled studies are required to validate these preliminary results. TRIAL REGISTRATION: The trial has been registered with the United States National Library of Medicine at the National Institutes of Health Registry of Clinical Trials under the code NCT05941143 on July 12, 2023.
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COVID-19 , Atención Plena , Anciano , Humanos , Cognición , COVID-19/psicología , Internet , Atención Plena/métodos , Pandemias , Resultado del Tratamiento , Estados Unidos , Comunicación por Videoconferencia , Estrés PsicológicoRESUMEN
PURPOSE: Several [18F]Flortaucipir cutoffs have been proposed for tau PET positivity (T+) in Alzheimer's disease (AD), but none were data-driven. The aim of this study was to establish and validate unsupervised T+ cutoffs by applying Gaussian mixture models (GMM). METHODS: Amyloid negative (A-) cognitively normal (CN) and amyloid positive (A+) AD-related dementia (ADRD) subjects from ADNI (n=269) were included. ADNI (n=475) and Geneva Memory Clinic (GMC) cohorts (n=98) were used for validation. GMM-based cutoffs were extracted for the temporal meta-ROI, and validated against previously published cutoffs and visual rating. RESULTS: GMM-based cutoffs classified less subjects as T+, mainly in the A- CN (<3.4% vs >28.5%) and A+ CN (<14.5% vs >42.9%) groups and showed higher agreement with visual rating (ICC=0.91 vs ICC<0.62) than published cutoffs. CONCLUSION: We provided reliable data-driven [18F]Flortaucipir cutoffs for in vivo T+ detection in AD. These cutoffs might be useful to select participants in clinical and research studies.
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Enfermedad de Alzheimer , Disfunción Cognitiva , Humanos , Enfermedad de Alzheimer/diagnóstico por imagen , Proteínas tau , Péptidos beta-Amiloides , Tomografía de Emisión de Positrones , AmiloideRESUMEN
BACKGROUND: The workload associated with caring for a person with dementia (PwD) could negatively affect informal caregivers' physical and mental health. According to the recent literature, there is a need for studies testing the implementation of affordable and accessible interventions for improving caregivers' well-being. AIMS: This study aimed to explore the feasibility and effectiveness of an 8 week eHealth psychoeducation intervention held during the COVID-19 pandemic in Italy in reducing the psychological burden and neuroendocrine markers of stress in caregivers of PwD. METHODS: Forty-one informal caregivers of PwD completed the eHealth psychoeducation intervention. Self-reported (i.e., caregiver burden, anxiety symptoms, depressive symptoms, and caregiver self-efficacy) and cortisol measurements were collected before and after the intervention. RESULTS: Following the intervention, the caregivers' self-efficacy regarding the ability to respond to disruptive behaviours improved (t = - 2.817, p = 0.007), anxiety and burden levels decreased (state anxiety: t = 3.170, p = 0.003; trait anxiety: t = 2.327, p = 0.025; caregiver burden: t = 2.290, p = 0.027), while depressive symptoms and cortisol levels did not change significantly. Correlation analyses showed that the increase in self-efficacy was positively associated with the improvement of caregiver burden from pre- to post-intervention (r = 0.386, p = 0.014). The intervention had a low rate of dropout (n = 1, due to the patient's death) and high levels of appreciation. DISCUSSION: The positive evidence and participation rate support the feasibility and effectiveness of the proposed eHealth psychoeducational intervention to meet the need for knowledge of disease management and possibly reduce detrimental effects on caregivers' psychological well-being. CONCLUSION: Further placebo-controlled trials are needed to test the generalizability and specificity of our results.
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COVID-19 , Demencia , Telemedicina , Humanos , Cuidadores/psicología , Proyectos Piloto , Demencia/terapia , Hidrocortisona , Pandemias , COVID-19/epidemiología , Italia , Calidad de VidaRESUMEN
BACKGROUND: Auraptene (AUR) and naringenin (NAR) are citrus-derived phytochemicals that influence several biological mechanisms associated with cognitive decline, including neuronal damage, oxidative stress and inflammation. Clinical evidence of the efficacy of a nutraceutical with the potential to enhance cognitive function in cohorts at risk of cognitive decline would be of great value from a preventive perspective. The primary aim of this study is to determine the cognitive effects of a 36-week treatment with citrus peel extract standardized in levels of AUR and NAR in older adults experiencing subjective cognitive decline (SCD). The secondary aim is to determine the effects of these phytochemicals on blood-based biomarkers indicative of neuronal damage, oxidative stress, and inflammation. METHODS: Eighty older persons with SCD will be recruited and randomly assigned to receive the active treatment (400 mg of citrus peel extract containing 0.1 mg of AUR and 3 mg of NAR) or the placebo at a 1:1 ratio for 36 weeks. The primary endpoint is a change in the Repeatable Battery for the Assessment of Neuropsychological Status score from baseline to weeks 18 and 36. Other cognitive outcomes will include changes in verbal and nonverbal memory, attention, executive and visuospatial functions. Blood samples will be collected from a consecutive subsample of 60 participants. The secondary endpoint is a change in interleukin-8 levels over the 36-week period. Other biological outcomes include changes in markers of neuronal damage, oxidative stress, and pro- and anti-inflammatory cytokines. CONCLUSION: This study will evaluate whether an intervention with citrus peel extract standardized in levels of AUR and NAR has cognitive and biological effects in older adults with SCD, facilitating the establishment of nutrition intervention in people at risk of cognitive decline. TRIAL REGISTRATION: The trial is registered with the United States National Library of Medicine at the National Institutes of Health Registry of Clinical Trials under the code NCT04744922 on February 9th, 2021 ( https://www. CLINICALTRIALS: gov/ct2/show/NCT04744922 ).
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Citrus , Disfunción Cognitiva , Antiinflamatorios , Biomarcadores , Cognición , Disfunción Cognitiva/tratamiento farmacológico , Humanos , Inflamación/tratamiento farmacológico , Interleucina-8/farmacología , Interleucina-8/uso terapéutico , Fitoquímicos/farmacología , Extractos Vegetales/farmacología , Extractos Vegetales/uso terapéuticoRESUMEN
BACKGROUND: The amygdala and the hippocampus are two limbic structures that play a critical role in cognition and behavior, however their manual segmentation and that of their smaller nuclei/subfields in multicenter datasets is time consuming and difficult due to the low contrast of standard MRI. Here, we assessed the reliability of the automated segmentation of amygdalar nuclei and hippocampal subfields across sites and vendors using FreeSurfer in two independent cohorts of older and younger healthy adults. METHODS: Sixty-five healthy older (cohort 1) and 68 younger subjects (cohort 2), from the PharmaCog and CoRR consortia, underwent repeated 3D-T1 MRI (interval 1-90 days). Segmentation was performed using FreeSurfer v6.0. Reliability was assessed using volume reproducibility error (ε) and spatial overlapping coefficient (DICE) between test and retest session. RESULTS: Significant MRI site and vendor effects (p â< â.05) were found in a few subfields/nuclei for the ε, while extensive effects were found for the DICE score of most subfields/nuclei. Reliability was strongly influenced by volume, as ε correlated negatively and DICE correlated positively with volume size of structures (absolute value of Spearman's r correlations >0.43, p â< â1.39E-36). In particular, volumes larger than 200 âmm3 (for amygdalar nuclei) and 300 âmm3 (for hippocampal subfields, except for molecular layer) had the best test-retest reproducibility (ε â< â5% and DICE â> â0.80). CONCLUSION: Our results support the use of volumetric measures of larger amygdalar nuclei and hippocampal subfields in multisite MRI studies. These measures could be useful for disease tracking and assessment of efficacy in drug trials.
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Amígdala del Cerebelo/anatomía & histología , Hipocampo/anatomía & histología , Procesamiento de Imagen Asistido por Computador/normas , Neuroimagen/normas , Programas Informáticos , Adulto , Anciano , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Imagen por Resonancia Magnética/normas , Masculino , Persona de Mediana Edad , Neuroimagen/métodos , Reproducibilidad de los ResultadosRESUMEN
The genetic basis and human-specific character of schizophrenia has led to the hypothesis that human brain evolution may have played a role in the development of the disorder. We examined schizophrenia-related changes in brain connectivity in the context of evolutionary changes in human brain wiring by comparing in vivo neuroimaging data from humans and chimpanzees, one of our closest living evolutionary relatives and a species with which we share a very recent common ancestor. We contrasted the connectome layout between the chimpanzee and human brain and compared differences with the pattern of schizophrenia-related changes in brain connectivity as observed in patients. We show evidence of evolutionary modifications of human brain connectivity to significantly overlap with the cortical pattern of schizophrenia-related dysconnectivity (P < 0.001, permutation testing). We validated these effects in three additional, independent schizophrenia datasets. We further assessed the specificity of effects by examining brain dysconnectivity patterns in seven other psychiatric and neurological brain disorders (including, among others, major depressive disorder and obsessive-compulsive disorder, arguably characterized by behavioural symptoms that are less specific to humans), which showed no such associations with modifications of human brain connectivity. Comparisons of brain connectivity across humans, chimpanzee and macaques further suggest that features of connectivity that evolved in the human lineage showed the strongest association to the disorder, that is, brain circuits potentially related to human evolutionary specializations. Taken together, our findings suggest that human-specific features of connectome organization may be enriched for changes in brain connectivity related to schizophrenia. Modifications in human brain connectivity in service of higher order brain functions may have potentially also rendered the brain vulnerable to brain dysfunction.
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Evolución Biológica , Encéfalo/fisiopatología , Red Nerviosa/fisiopatología , Esquizofrenia/fisiopatología , Adulto , Animales , Encéfalo/diagnóstico por imagen , Conectoma , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Red Nerviosa/diagnóstico por imagen , Pan troglodytes , Esquizofrenia/diagnóstico por imagenRESUMEN
BACKGROUND: Borderline Personality Disorder (BPD) is a complex and debilitating disorder, characterized by deficits in metacognition and emotion dysregulation. The "gold standard" treatment for this disorder is psychotherapy with pharmacotherapy as an adjunctive treatment to target state symptoms. The present randomized clinical trial aims to assess the clinical and neurobiological changes following Metacognitive Interpersonal Therapy (MIT) compared with Structured Clinical Management (SCM) derived from specific recommendations in APA (American Psychiatric Association) guidelines for BPD. METHODS: The study design is a randomized parallel controlled clinical trial and will include 80 BPD outpatients, aged 18-45 enrolled at 2 recruitment centers. Primary outcome will be the clinical change in emotion regulation capacities assessed with the Difficulties in Emotion Regulation Scale (DERS). We will also investigated the effect of psychotherapy on metacognitive abilities and several clinical features such as BPD symptomatology, general psychopathology, depression, personal functioning, and trait dimensions (anger, impulsivity, alexithymia). We will evaluate changes in brain connectivity patterns and during the view of emotional pictures. A multidimensional assessment will be performed at the baseline, at 6, 12, 18 months. We will obtain structural and functional Magnetic Resonance Images (MRIs) in MIT-Treated BPD (N = 30) and SCM-treated BPD (N = 30) at baseline and after treatment, as well as in a group of 30 healthy and unrelated volunteers that will be scanned once for comparison. DISCUSSION: The present study could contribute to elucidate the neurobiological mechanisms underlying psychotherapy efficacy. The inclusion of a multidisciplinary study protocol will allow to study BPD considering different features that can affect the treatment response and their reciprocal relationships. TRIAL REGISTRATION: NCT02370316 . Registered 02/24/2015.
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Trastorno de Personalidad Limítrofe/psicología , Trastorno de Personalidad Limítrofe/terapia , Psicoterapia Interpersonal/métodos , Metacognición/fisiología , Adolescente , Adulto , Trastorno de Personalidad Limítrofe/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento , Adulto JovenRESUMEN
Non-invasive brain stimulation (NIBS) is emerging as a promising rehabilitation tool for a number of neurodegenerative diseases. However, the therapeutic mechanisms of NIBS are not completely understood. In this review, we will summarize NIBS results in the context of brain imaging studies of functional connectivity and metabolites to gain insight into the possible mechanisms underlying recovery. We will briefly discuss how the clinical manifestations of common neurodegenerative disorders may be related with aberrant connectivity within large-scale neural networks. We will then focus on recent studies combining resting-state functional magnetic resonance imaging with NIBS to delineate how stimulation of different brain regions induce complex network modifications, both at the local and distal level. Moreover, we will review studies combining magnetic resonance spectroscopy and NIBS to investigate how microscale changes are related to modifications of large-scale networks. Finally, we will re-examine previous NIBS studies in dementia in light of this network perspective. A better understanding of NIBS impact on the functionality of large-scale brain networks may be useful to design beneficial treatments for neurodegenerative disorders.
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Encéfalo/fisiopatología , Demencia/fisiopatología , Enfermedades Neurodegenerativas/terapia , Plasticidad Neuronal/fisiología , Encéfalo/cirugía , Demencia/terapia , Humanos , Imagen por Resonancia Magnética , Enfermedades Neurodegenerativas/fisiopatología , Resultado del TratamientoRESUMEN
The European DTI Study on Dementia (EDSD) is a multicenter framework created to study the diagnostic accuracy and inter-site variability of DTI-derived markers in patients with manifest and prodromal Alzheimer's disease (AD). The dynamically growing database presently includes 493 DTI, 512 T1-weighted MRI, and 300 FLAIR scans from patients with AD dementia, patients with Mild Cognitive Impairment (MCI) and matched Healthy Controls, acquired on 13 different scanner platforms. The imaging data is publicly available, along with the subjects' demographic and clinical characterization. Detailed neuropsychological information, cerebrospinal fluid information on biomarkers and clinical follow-up diagnoses are included for a subset of subjects. This paper describes the rationale and structure of the EDSD, summarizes the available data, and explains how to gain access to the database. The EDSD is a useful database for researchers seeking to investigate the contribution of DTI to dementia diagnostics.
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Enfermedad de Alzheimer/diagnóstico por imagen , Disfunción Cognitiva/diagnóstico por imagen , Bases de Datos Factuales , Imagen de Difusión Tensora , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Difusión de la Información , Masculino , Persona de Mediana EdadRESUMEN
PURPOSE OF REVIEW: Noninvasive brain stimulation (NIBS) is increasingly used in the field of dementia as a therapeutic option; however, evidence of clinical efficacy is limited, and the mechanism of action remains unknown. This review summarizes how functional imaging could contribute to the design of targeted and effective NIBS interventions for dementia. RECENT FINDINGS: Resting-state functional magnetic resonance imaging (fMRI) has largely contributed to understanding brain dysfunction in dementia by identifying disease-specific networks. Resting-state fMRI might inform on a number of factors critical for the conduction of effective NIBS trials, such as definition of stimulation paradigms and choice of the stimulation target. In addition, fMRI may contribute to the understanding of the mechanisms of action of NIBS, and provide a tool to monitor treatment efficacy. SUMMARY: Functional imaging is a promising approach for the development of hypothesis-driven, targeted stimulation approaches in the field of dementia.
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Encéfalo/diagnóstico por imagen , Demencia/diagnóstico por imagen , Terapia por Estimulación Eléctrica/métodos , Red Nerviosa/diagnóstico por imagen , Encéfalo/fisiopatología , Demencia/fisiopatología , Humanos , Imagen por Resonancia Magnética , Red Nerviosa/fisiopatología , Resultado del TratamientoRESUMEN
BACKGROUND: Beliefs of dementia experts about the pathogenic role of amyloid in Alzheimer's disease (AD) may affect the use of amyloid positron emission tomography (PET). OBJECTIVE: To assess the role attributed to amyloid in AD pathogenesis by Italian dementia experts, and whether this modulates the impact of amyloid PET results in their diagnostic workup. METHODS: 22 dementia experts rated their beliefs about the pathogenic role of amyloid. Then, we asked them to rate the probability of change in diagnosis based on the result of amyloid PET for 7 case vignettes, depicting patients who initially received a diagnosis based on a comprehensive workup and later received amyloid PET results consistent or inconsistent with the clinical picture. RESULTS: 55% of the experts assigned a dominant role to amyloid, and 32% attributed a similar role to amyloid and tau in AD pathogenesis. The probability of change in diagnosis ranged from 17% (SD = 21.6) for cases with consistent to 51% (SD = 34) for cases with inconsistent PET versus clinical data. Diagnostic change was not biased by the clinicians' beliefs about AD pathogenesis. CONCLUSIONS: This work supports an unbiased interpretation of amyloid PET across different beliefs about the pathogenic role of amyloid, and a belief-independent reluctance to change diagnosis in cases where change is expected and recommended.
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Amiloide/metabolismo , Actitud del Personal de Salud , Médicos/psicología , Tomografía de Emisión de Positrones/psicología , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/metabolismo , Diagnóstico Diferencial , Humanos , Italia , Proyectos Piloto , Proteínas tau/metabolismoRESUMEN
BACKGROUND: The European Alzheimer's Disease Consortium and Alzheimer's Disease Neuroimaging Initiative (ADNI) Harmonized Protocol (HarP) is a Delphi definition of manual hippocampal segmentation from magnetic resonance imaging (MRI) that can be used as the standard of truth to train new tracers, and to validate automated segmentation algorithms. Training requires large and representative data sets of segmented hippocampi. This work aims to produce a set of HarP labels for the proper training and certification of tracers and algorithms. METHODS: Sixty-eight 1.5 T and 67 3 T volumetric structural ADNI scans from different subjects, balanced by age, medial temporal atrophy, and scanner manufacturer, were segmented by five qualified HarP tracers whose absolute interrater intraclass correlation coefficients were 0.953 and 0.975 (left and right). Labels were validated as HarP compliant through centralized quality check and correction. RESULTS: Hippocampal volumes (mm(3)) were as follows: controls: left = 3060 (standard deviation [SD], 502), right = 3120 (SD, 897); mild cognitive impairment (MCI): left = 2596 (SD, 447), right = 2686 (SD, 473); and Alzheimer's disease (AD): left = 2301 (SD, 492), right = 2445 (SD, 525). Volumes significantly correlated with atrophy severity at Scheltens' scale (Spearman's ρ = <-0.468, P = <.0005). Cerebrospinal fluid spaces (mm(3)) were as follows: controls: left = 23 (32), right = 25 (25); MCI: left = 15 (13), right = 22 (16); and AD: left = 11 (13), right = 20 (25). Five subjects (3.7%) presented with unusual anatomy. CONCLUSIONS: This work provides reference hippocampal labels for the training and certification of automated segmentation algorithms. The publicly released labels will allow the widespread implementation of the standard segmentation protocol.
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Algoritmos , Hipocampo/patología , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética/métodos , Neuroimagen/métodos , Reconocimiento de Normas Patrones Automatizadas/métodos , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/patología , Atrofia , Disfunción Cognitiva/patología , Femenino , Lateralidad Funcional , Hipocampo/anatomía & histología , Humanos , Imagenología Tridimensional/métodos , Imagen por Resonancia Magnética/instrumentación , Masculino , Persona de Mediana Edad , Tamaño de los Órganos , Reproducibilidad de los Resultados , Lóbulo Temporal/patologíaRESUMEN
BACKGROUND: Clinical studies have shown that hippocampal atrophy is present before dementia in people with memory deficits and can predict dementia development. The question remains whether this association holds in the general population. This is of interest for the possible use of hippocampal atrophy to screen population for preventive interventions. The aim of this study was to assess hippocampal volume and shape abnormalities in elderly adults with memory deficits in a cross-sectional population-based study. METHODS: We included individuals participating in the Italian Project on the Epidemiology of Alzheimer Disease (IPREA) study: 75 cognitively normal individuals (HC), 31 individuals with memory deficits (MEM), and 31 individuals with memory deficits not otherwise specified (MEMnos). Hippocampal volumes and shape were extracted through manual tracing and the growing and adaptive meshes (GAMEs) shape-modeling algorithm. We investigated between-group differences in hippocampal volume and shape, and correlations with memory deficits. RESULTS: In MEM participants, hippocampal volumes were significantly smaller than in HC and were mildly associated with worse memory scores. Memory-associated shape changes mapped to the anterior hippocampus. Shape-based analysis detected no significant difference between MEM and HC, while MEMnos showed shape changes in the posterior hippocampus compared with HC and MEM groups. CONCLUSIONS: These findings support the discriminant validity of hippocampal volumetry as a biomarker of memory impairment in the general population. The detection of shape changes in MEMnos but not in MEM participants suggests that shape-based biomarkers might lack sensitivity to detect Alzheimer's-like pathology in the general population.
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Hipocampo/patología , Trastornos de la Memoria/patología , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/patología , Atrofia , Biomarcadores , Estudios Transversales , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Trastornos de la Memoria/diagnóstico , Neuroimagen , Tamaño de los ÓrganosRESUMEN
BACKGROUND: To investigate the patterns of brain atrophy, white matter (WM) tract changes, and functional connectivity (FC) abnormalities in asymptomatic granulin (GRN) mutation carriers. METHODS: Ten cognitively normal subjects (five mutation carriers, GRN+; years to estimated disease onset: 12±7; five mutation noncarriers, GRN-) underwent a clinical and imaging (structural, diffusion tensor, and resting-state functional magnetic resonance imaging) assessment. Brain atrophy was measured with cortical thickness analysis, WM abnormalities with tract-based spatial statistics, and FC with independent component analysis. RESULTS: GRN+ showed smaller cortical thickness than GRN- in the right orbitofrontal and precentral gyrus and left rostral middle frontal gyrus. WM tracts abnormalities were limited to increased axial diffusivity in the right cingulum, superior longitudinal fasciculus, and corticospinal tract. There were no differences in FC of resting-state networks. CONCLUSION: Brain atrophy and WM tract abnormalities in frontal-parietal circuits can be detected at least a decade before the estimated symptom onset in asymptomatic mutation carriers.
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Encéfalo/anomalías , Encéfalo/fisiopatología , Heterocigoto , Péptidos y Proteínas de Señalización Intercelular/genética , Mutación , Adulto , Atrofia , Imagen de Difusión Tensora , Femenino , Humanos , Imagen por Resonancia Magnética , Persona de Mediana Edad , Vías Nerviosas/anomalías , Vías Nerviosas/fisiopatología , Tamaño de los Órganos , Progranulinas , Descanso , Sustancia Blanca/anomalías , Sustancia Blanca/fisiopatologíaRESUMEN
INTRODUCTION: We investigated in vivo the microstructural integrity of the pathway connecting the locus coeruleus to the transentorhinal cortex (LC-TEC) in patients with Alzheimer's disease (AD) and frontotemporal dementia (FTD). METHODS: Diffusion-weighted MRI scans were collected for 21 AD, 20 behavioral variants of FTD (bvFTD), and 20 controls. Fractional anisotropy (FA), mean, axial, and radial diffusivities (MD, AxD, RD) were computed in the LC-TEC pathway using a normative atlas. Atrophy was assessed using cortical thickness and correlated with microstructural measures. RESULTS: We found (i) higher RD in AD than controls; (ii) higher MD, RD, and AxD, and lower FA in bvFTD than controls and AD; and (iii) a negative association between LC-TEC MD, RD, and AxD, and entorhinal cortex (EC) thickness in bvFTD (all p < 0.050). DISCUSSION: LC-TEC microstructural alterations are more pronounced in bvFTD than AD, possibly reflecting neurodegeneration secondary to EC atrophy. Highlights: Microstructural integrity of LC-TEC pathway is understudied in AD and bvFTD.LC-TEC microstructural alterations are present in both AD and bvFTD.Greater LC-TEC microstructural alterations in bvFTD than AD.LC-TEC microstructural alterations in bvFTD are associated to EC neurodegeneration.
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This study investigated gray matter (GM) and white matter (WM) damage in 89 patients at different clinical stages of Parkinson's disease (PD) (17 early, 46 mild, 14 moderate, and 12 severe) to differentiate the trajectories of tissue injury in this condition. PD patients had a very little GM atrophy even at the more advanced stages of the disease. Microstructural damage to the WM occurs with increasing PD severity and involves the brainstem, thalamocortical pathways, olfactory tracts, as well as the major interhemispheric, limbic, and extramotor association tracts. The most marked WM damage was found in moderate vs. mild cases. WM damage correlated with the degree of global cognitive deficits. WM abnormalities beyond the nigrostriatal system accumulate with increasing PD severity. WM damage is likely to contribute to the more severe motor and nonmotor dysfunctions occurring in patients at the later stages.
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Daño Encefálico Crónico/patología , Mapeo Encefálico/métodos , Encéfalo/patología , Enfermedad de Parkinson/patología , Edad de Inicio , Anciano , Anciano de 80 o más Años , Atrofia , Biomarcadores , Daño Encefálico Crónico/etiología , Daño Encefálico Crónico/psicología , Trastornos del Conocimiento/etiología , Trastornos del Conocimiento/psicología , Progresión de la Enfermedad , Imagen Eco-Planar , Escolaridad , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Vías Nerviosas/patología , Pruebas Neuropsicológicas , Enfermedad de Parkinson/complicaciones , Enfermedad de Parkinson/psicologíaRESUMEN
BACKGROUND: Gray matter atrophy is regarded as a valid marker of neurodegeneration in Alzheimer's disease (AD), but few studies have investigated in detail the topographic changes associated with normal aging. In addition, few studies have compared the changes in the earliest clinical stage of AD (prodromal AD (pAD)) with those of healthy aging. Here we aimed to investigate the topographical distribution of age-related cortical atrophy and to compare it with that associated with prodromal and estabilished AD. METHODS: Structural T1-weighted high-resolution brain magnetic resonance imaging scans were acquired from 60 healthy volunteers (20 young adults, YA: age 32.7 +/- 4.5 years; 40 elderly subjects, HE: age 71.3 +/- 6.2 years), 16 mild cognitive impairment subjects who converted to AD within 2 years (prodromal AD, pAD: age 72.8 +/- 5.4), and 20 mild to moderate AD patients (mAD, age 72.5 +/- 10.3). Cortical gray matter differences were investigated using a surface-based anatomical mesh modeling technique (cortical pattern matching) and region-of-interest (ROI) analyses based on hypothesized brain networks taught to have a functional and a structural link to each other. Differences in cortical atrophy were assessed between groups, as well as the effect of age within groups. RESULTS: HE compared to YA showed a 10-30% deficit in cortical gray matter in widespread frontal, temporal, and parietal regions (p = 0.0001 by permutation testing), 6-13% loss in the visual and sensorimotor cortices (p < 0.01) and up to 13% loss in the direct hippocampal pathway ROIs (p < 0.001). pAD patients showed on average 8-9% cortical loss compared to HE (p < 0.0001), mainly in the left (up to 6% loss, p = 0.06) and right polysynaptic hippocampal pathway ROIs (up to 8% loss, p = 0.01), and in the left and right olfactory/orbitofrontal cortex (up to 12-15% loss, p < 0.001). The pattern of cortical atrophy in mAD versus HE was similar to that in pAD, but was more severe in the direct hippocampal pathway ROIs and sensorimotor, visual and temporal cortices (13-15% loss compared with HE, p < 0.0001). CONCLUSION: Gray matter loss occurs during aging with rates of atrophy even more severe than that observed during the course of AD. These changes may be caused by normal mechanisms. In pAD, cortical atrophy due to disease is milder than that due to aging, maybe resulting from a slowed down velocity of cell loss, but affects specific brain areas. These findings are consistent with the view that AD is not merely accelerated aging.
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Envejecimiento , Enfermedad de Alzheimer/patología , Mapeo Encefálico , Corteza Cerebral/patología , Adulto , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Atrofia/patología , Disfunción Cognitiva/patología , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Escala del Estado Mental , Persona de Mediana Edad , Pruebas Neuropsicológicas , Estadísticas no ParamétricasRESUMEN
BACKGROUND: Increasing evidence links the gut microbiota (GM) to Alzheimer's disease (AD) but the mechanisms through which gut bacteria influence the brain are still unclear. This study tests the hypothesis that GM and mediators of the microbiota-gut-brain axis (MGBA) are associated with the amyloid cascade in sporadic AD. METHODS: We included 34 patients with cognitive impairment due to AD (CI-AD), 37 patients with cognitive impairment not due to AD (CI-NAD), and 13 cognitively unimpaired persons (CU). We studied the following systems: (1) fecal GM, with 16S rRNA sequencing; (2) a panel of putative MGBA mediators in the blood including immune and endothelial markers as bacterial products (i.e., lipopolysaccharide, LPS), cell adhesion molecules (CAMs) indicative of endothelial dysfunction (VCAM-1, PECAM-1), vascular changes (P-, E-Selectin), and upregulated after infections (NCAM, ICAM-1), as well as pro- (IL1ß, IL6, TNFα, IL18) and anti- (IL10) inflammatory cytokines; (3) the amyloid cascade with amyloid PET, plasma phosphorylated tau (pTau-181, for tau pathology), neurofilament light chain (NfL, for neurodegeneration), and global cognition measured using MMSE and ADAScog. We performed 3-group comparisons of markers in the 3 systems and calculated correlation matrices for the pooled group of CI-AD and CU as well as CI-NAD and CU. Patterns of associations based on Spearman's rho were used to validate the study hypothesis. RESULTS: CI-AD were characterized by (1) higher abundance of Clostridia_UCG-014 and decreased abundance of Moryella and Blautia (p < .04); (2) elevated levels of LPS (p < .03), upregulation of CAMs, Il1ß, IL6, and TNFα, and downregulation of IL10 (p < .05); (3) increased brain amyloid, plasma pTau-181, and NfL (p < 0.004) compared with the other groups. CI-NAD showed (1) higher abundance of [Eubacterium] coprostanoligenes group and Collinsella and decreased abundance of Lachnospiraceae_ND3007_group, [Ruminococcus]_gnavus_group and Oscillibacter (p < .03); (2) upregulation of PECAM-1 and TNFα (p < .03); (4) increased plasma levels of NfL (p < .02) compared with CU. Different GM genera were associated with immune and endothelial markers in both CI-NAD and CI-AD but these mediators were widely related to amyloid cascade markers only in CI-AD. CONCLUSIONS: Specific bacterial genera are associated with immune and endothelial MGBA mediators, and these are associated with amyloid cascade markers in sporadic AD. The physiological mechanisms linking the GM to the amyloid cascade should be further investigated to elucidate their potential therapeutic implications.
Asunto(s)
Enfermedad de Alzheimer , Humanos , Enfermedad de Alzheimer/metabolismo , Factor de Necrosis Tumoral alfa , Eje Cerebro-Intestino , Lipopolisacáridos , Molécula-1 de Adhesión Celular Endotelial de Plaqueta , ARN Ribosómico 16S , Interleucina-10 , Interleucina-6 , NAD , Biomarcadores , Péptidos beta-AmiloidesRESUMEN
Different psychotherapeutic approaches demonstrated their efficacy but the possible neurobiological mechanism underlying the effect of psychotherapy in borderline personality disorder (BPD) patients is poorly investigated. We assessed the effects of metacognitive interpersonal therapy (MIT) on BPD features and other dimensions compared to structured clinical management (SCM). We also assessed changes in amygdala activation by viewing emotional pictures after psychotherapy. One hundred forty-one patients were referred and 78 BPD outpatients were included and randomized to MIT or SCM. Primary outcome was emotional dysregulation assessed with the Difficulties in Emotion Regulation Scale (DERS). We also assessed BPD symptomatology, number of PD criteria, metacognitive abilities, state-psychopathology, depression, impulsiveness, interpersonal functioning, and alexithymia. A subset of 60 patients underwent functional magnetic resonance imaging before and after 1 year of psychotherapy to assess amygdala activation by viewing standardized emotional pictures (secondary outcome). DERS scores decreased in both groups (time effect p < .001). The Cohen's d effect size for change (baseline posttreatment) on DERS was very large (d = 0.84) in MIT, and large (d = 0.76) in SCM. Both groups significantly improved in depressive symptoms, state-psychopathology, alexithymia, and interpersonal functioning. MIT showed larger effect on metacognitive functions than SCM (Time × Group p < .001). Both interventions showed a significant effect on BPD symptomatology although SCM group showed a larger decrease. On the contrary, MIT group showed larger decrease in impulsivity and number of PD criteria. Interestingly, both MIT and SCM modulated amygdala activation in BPD patients. MIT is a valid and effective psychotherapy for BPD with an impact on amygdala activation. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
Asunto(s)
Trastorno de Personalidad Limítrofe , Metacognición , Humanos , Trastorno de Personalidad Limítrofe/diagnóstico por imagen , Trastorno de Personalidad Limítrofe/terapia , Psicoterapia/métodos , Emociones , Neuroimagen , Metacognición/fisiologíaRESUMEN
Alzheimer's disease (AD) is a genetically complex disorder. In addition to the relatively small number of pathogenic variants causing autosomal dominant AD, many others have been associated with the much more common sporadic form. The E4 allele of the Apolipoprotein E (APOE) is the first discovered genetic risk factor for AD. In addition, more than 70 genetic risk loci contributing to AD have been identified. Current guidelines do not recommend AD susceptibility genetic testing in cognitively healthy adults because the implications for clinical care are limited. However, secondary prevention clinical trials of disease-modifying therapies enrol individuals based on genetic criteria, and participants are often informed of APOE testing results. Moreover, the availability of direct-to-consumer genetic testing allows individuals to learn their own AD genetic risk profile without medical supervision. A number of research protocols for AD susceptibility genetic testing have been proposed. In Italy, disclosure processes and protocols beyond those developed for inherited dementia have not been established yet. We reviewed the literature on the current practice and clinical issues related to disclosing AD genetic risk to cognitively healthy individuals and provide suggestions that may help to develop specific guidelines at the national level.