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1.
Ann Neurol ; 93(5): 911-921, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36585914

RESUMEN

OBJECTIVE: The purpose of this study was to explore longitudinal changes in synaptic density after ischemic stroke in vivo with synaptic vesicle protein 2A (SV2A) positron emission tomography (PET). METHODS: We recruited patients with an ischemic stroke to undergo 11 C-UCB-J PET/MR within the first month and 6 months after the stroke. We investigated longitudinal changes of partial volume corrected 11 C-UCB-J standardized uptake value ratio (SUVR; relative to centrum semiovale) within the ischemic lesion, peri-ischemic area and unaffected ipsilesional and contralesional grey matter. We also explored crossed cerebellar diaschisis at 6 months. Additionally, we defined brain regions potentially influencing upper limb motor recovery after stroke and studied 11 C-UCB-J SUVR evolution in comparison to baseline. RESULTS: In 13 patients (age = 67 ± 15 years) we observed decreasing 11 C-UCB-J SUVR in the ischemic lesion (ΔSUVR = -1.0, p = 0.001) and peri-ischemic area (ΔSUVR = -0.31, p = 0.02) at 6 months after stroke compared to baseline. Crossed cerebellar diaschisis as measured with 11 C-UCB-J SUVR was present in 11 of 13 (85%) patients at 6 months. The 11 C-UCB-J SUVR did not augment in ipsilesional or contralesional brain regions associated with motor recovery. On the contrary, there was an overall trend of declining 11 C-UCB-J SUVR in these brain regions, reaching statistical significance only in the nonlesioned part of the ipsilesional supplementary motor area (ΔSUVR = -0.83, p = 0.046). INTERPRETATION: At 6 months after stroke, synaptic density further declined in the ischemic lesion and peri-ischemic area compared to baseline. Brain regions previously demonstrated to be associated with motor recovery after stroke did not show increases in synaptic density. ANN NEUROL 2023;93:911-921.


Asunto(s)
Diásquisis , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Pirrolidinonas/metabolismo , Glicoproteínas de Membrana/metabolismo , Piridinas/metabolismo , Tomografía de Emisión de Positrones/métodos , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/metabolismo
2.
Psychol Med ; 54(3): 592-600, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37577955

RESUMEN

BACKGROUND: Very-late-onset schizophrenia-like psychosis (VLOSLP) is associated with significant burden. Its clinical importance is increasing as the global population of older adults rises, yet owing to limited research in this population, the neurobiological underpinnings of VLOSP remain insufficiently clarified. Here we address this knowledge gap using novel morphometry techniques to investigate grey matter volume (GMV) differences between VLOSLP and healthy older adults, and their correlations with neuropsychological scores. METHODS: In this cross-sectional study, we investigated whole-brain GMV differences between 35 individuals with VLOSLP (mean age 76.7, 26 female) and 36 healthy controls (mean age 75.7, 27 female) using whole-brain voxel-based morphometry (VBM) and supplementary source-based morphometry (SBM) on high resolution 3D T1-weighted MRI images. Additionally, we investigated relationships between GMV differences and cognitive function assessed with an extensive neuropsychological battery. RESULTS: VBM showed lower GMV in the thalamus, left inferior frontal gyrus and left insula in patients with VLOSLP compared to healthy controls. SBM revealed lower thalamo-temporal GMV in patients with VLOSLP. Processing speed, selective attention, mental flexibility, working memory, verbal memory, semantic fluency and confrontation naming were impaired in patients with VLOSLP. Correlations between thalamic volumes and memory function were significant within the group of individuals with VLOSLP, whereas no significant associations remained in the healthy controls. CONCLUSIONS: Lower GMV in the thalamus and fronto-temporal regions may be part of the underlying neurobiology of VLOSLP, with lower thalamic GMV contributing to memory impairment in the disorder.


Asunto(s)
Trastornos Psicóticos , Esquizofrenia , Humanos , Femenino , Anciano , Sustancia Gris/diagnóstico por imagen , Esquizofrenia/diagnóstico por imagen , Estudios Transversales , Encéfalo/diagnóstico por imagen , Trastornos Psicóticos/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos
3.
Mol Psychiatry ; 2023 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-37985787

RESUMEN

Neurostimulation is a mainstream treatment option for major depression. Neuromodulation techniques apply repetitive magnetic or electrical stimulation to some neural target but significantly differ in their invasiveness, spatial selectivity, mechanism of action, and efficacy. Despite these differences, recent analyses of transcranial magnetic stimulation (TMS) and deep brain stimulation (DBS)-treated individuals converged on a common neural network that might have a causal role in treatment response. We set out to investigate if the neuronal underpinnings of electroconvulsive therapy (ECT) are similarly associated with this causal depression network (CDN). Our aim here is to provide a comprehensive analysis in three cohorts of patients segregated by electrode placement (N = 246 with right unilateral, 79 with bitemporal, and 61 with mixed) who underwent ECT. We conducted a data-driven, unsupervised multivariate neuroimaging analysis Principal Component Analysis (PCA) of the cortical and subcortical volume changes and electric field (EF) distribution to explore changes within the CDN associated with antidepressant outcomes. Despite the different treatment modalities (ECT vs TMS and DBS) and methodological approaches (structural vs functional networks), we found a highly similar pattern of change within the CDN in the three cohorts of patients (spatial similarity across 85 regions: r = 0.65, 0.58, 0.40, df = 83). Most importantly, the expression of this pattern correlated with clinical outcomes (t = -2.35, p = 0.019). This evidence further supports that treatment interventions converge on a CDN in depression. Optimizing modulation of this network could serve to improve the outcome of neurostimulation in depression.

4.
Cereb Cortex ; 33(3): 622-633, 2023 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-35253853

RESUMEN

The social brain hypothesis posits that a disproportionate encephalization in primates enabled to adapt behavior to a social context. Also, it has been proposed that phylogenetically recent brain areas are disproportionally affected by neurodegeneration. Using structural and functional magnetic resonance imaging, the present study investigates brain-behavior associations and neural integrity of hyperspecialized and domain-general cortical social brain areas in behavioral variant frontotemporal dementia (bvFTD). The results revealed that both structure and function of hyperspecialized social areas in the middle portion of the superior temporal sulcus (STS) are compromised in bvFTD, while no deterioration was observed in domain general social areas in the posterior STS. While the structural findings adhered to an anterior-posterior gradient, the functional group differences only occurred in the hyperspecialized locations. Activity in specialized regions was associated with structural integrity of the amygdala and with social deficits in bvFTD. In conclusion, the results are in line with the paleo-neurology hypothesis positing that neurodegeneration primarily hits cortical areas showing increased specialization, but also with the compatible alternative explanation that anterior STS regions degenerate earlier, based on stronger connections to and trans-neuronal spreading from regions affected early in bvFTD.


Asunto(s)
Demencia Frontotemporal , Humanos , Demencia Frontotemporal/patología , Encéfalo , Imagen por Resonancia Magnética/métodos , Mapeo Encefálico , Pruebas Neuropsicológicas
5.
BMC Med Imaging ; 24(1): 41, 2024 Feb 12.
Artículo en Inglés | MEDLINE | ID: mdl-38347458

RESUMEN

BACKGROUND: 18F-FDG brain PET is clinically used for differential diagnosis in cognitive dysfunction of unclear etiology and for exclusion of a neurodegenerative cause in patients with cognitive impairment in late-life psychiatric disorders. 18F-FDG PET measures regional glucose metabolism, which represents a combination of neuronal/synaptic activity but also astrocytic activity and neuroinflammation. Recently, imaging of synaptic vesicle protein 2 A (SV2A) has become available and was shown to be a proxy of synaptic density. This prospective study will investigate the use of 18F-SynVesT-1 for imaging SV2A and its discriminative power for differential diagnosis in cognitive disorders in a head-to-head comparison to 18F-FDG PET. In addition, simultaneous PET/MR allows an evaluation of contributing factors and the additional value of advanced MRI imaging to FDG/SV2A PET imaging will be investigated. In this work, the study design and protocol are depicted. METHODS: In this prospective, multimodal imaging study, 110 patients with uncertain diagnosis of cognitive impairment who are referred for 18F-FDG PET brain imaging in their diagnostic work-up in a tertiary memory clinic will be recruited. In addition, 40 healthy volunteers (HV) between 18 and 85 years (M/F) will be included. All study participants will undergo simultaneous 18F-SynVesT-1 PET/MR and an extensive neuropsychological evaluation. Amyloid status will be measured by PET using 18FNAV4694, in HV above 50 years of age. Structural T1-weighted and T2-weighted fluid-attenuated inversion recovery MR images, triple-tagging arterial spin labeling (ASL) and resting-state functional MRI (rs-fMRI) will be obtained. The study has been registered on ClinicalTrials.gov (NCT05384353) and is approved by the local Research Ethics Committee. DISCUSSION: The main endpoint of the study will be the comparison of the diagnostic accuracy between 18F-SynVesT-1 and 18F-FDG PET in cognitive disorders with uncertain etiology and in exclusion of a neurodegenerative cause in patients with cognitive impairment in late-life psychiatric disorders. The strength of the relationship between cognition and imaging data will be assessed, as well as the potential incremental diagnostic value of including MR volumetry, ASL perfusion and rs-fMRI.


Asunto(s)
Disfunción Cognitiva , Fluorodesoxiglucosa F18 , Piridinas , Pirrolidinas , Humanos , Estudios Prospectivos , Radioisótopos de Flúor , Disfunción Cognitiva/diagnóstico por imagen , Tomografía de Emisión de Positrones/métodos , Imagen por Resonancia Magnética/métodos
6.
Mov Disord ; 38(10): 1786-1794, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37574924

RESUMEN

OBJECTIVE: To investigate whether mild motor signs (MMS) in old age correlate with synaptic density in the brain. BACKGROUND: Normal aging is associated with a decline in movement quality and quantity, commonly termed "mild parkinsonian signs" or more recently MMS. Whether MMS stem from global brain aging or pathology within motor circuits remains unresolved. The synaptic vesicle glycoprotein 2A positron emission tomography (PET) ligand 11 C-UCB-J allows the investigation of brain-motor associations at the synaptic level in vivo. METHOD: Fifty-eight healthy older adults (≥50 years) were included from two monocentric control cohorts. Brain magnetic resonance imaging and 11 C-UCB-J PET data were available in 54 participants. 11 C-UCB-J PET binding was quantified by standardized uptake value ratio (SUVR) values in grey matter (GM) volumes of interest (VOIs): caudate, putamen, globus pallidus, substantia nigra, thalamus, cerebellum, and the frontal, parietal, temporal, and occipital cortex. Multiple linear regression analyses were performed with Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part III score measuring MMS as the dependent variable and mean SUVR values in each VOI as the independent variable with age, Fazekas score (white matter lesion [WML] load), VOI and cohort as covariates. RESULTS: Participants (68 ± 7.5 years; 52% female) had an average MDS-UPDRS part III score of 3.3 ± 2.8. The MDS-UPDRS part III score was inversely associated with synaptic density, independently of WML load or GM volume, in the caudate, substantia nigra, thalamus, cerebellum, and parietal, occipital, temporal cortex. Cohen's f2 showed moderate effect sizes for subcortical (range, 0.30-0.35), cortical (0.28-0.35) and cerebellar VOIs (0.31). CONCLUSION: MMS in healthy aging are associated with lower synaptic density throughout the brain. © 2023 International Parkinson and Movement Disorder Society.


Asunto(s)
Envejecimiento Saludable , Trastornos del Movimiento , Humanos , Femenino , Anciano , Masculino , Encéfalo/patología , Sustancia Gris/diagnóstico por imagen , Envejecimiento/metabolismo , Tomografía de Emisión de Positrones/métodos , Trastornos del Movimiento/patología
7.
Mol Psychiatry ; 27(10): 4244-4251, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35794185

RESUMEN

Next to amyloid and tau, synaptic loss is a key pathological hallmark in Alzheimer's disease, closely related to cognitive dysfunction and neurodegeneration. Tau is thought to cause synaptic loss, but this has not been experimentally verified in vivo. In a 2-year follow-up study, dual tracer PET-MR was performed in 12 amnestic MCI patients using 18F-MK-6240 for tau and 11C-UCB-J for SV2A as a proxy for synaptic density. Tau already accumulated in the neocortex at baseline with progression in Braak V/VI at follow-up. While synaptic loss was limited to limbic regions at baseline, it followed the specific tau pattern to stage IV/V regions two years later, indicating that tau spread might drive synaptic vulnerability. Moreover, synaptic density changes correlated to changes in cognitive function. This study shows for the first time in vivo that synaptic loss regionally follows tau accumulation after two years, providing a disease-modifying window of opportunity for (combined) tau-targeting therapies.


Asunto(s)
Enfermedad de Alzheimer , Disfunción Cognitiva , Humanos , Proteínas tau , Estudios de Seguimiento , Tomografía de Emisión de Positrones , Disfunción Cognitiva/patología , Enfermedad de Alzheimer/patología
8.
Alzheimers Dement ; 19(6): 2707-2729, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36749854

RESUMEN

INTRODUCTION: We aim to provide guidance on outcomes and measures for use in patients with Alzheimer's clinical syndrome. METHODS: A consensus group of 20 voting members nominated by 10 professional societies, and a non-voting chair, used a Delphi approach and modified GRADE criteria. RESULTS: Consensus was reached on priority outcomes (n = 66), measures (n = 49) and statements (n = 37) across nine domains. A number of outcomes and measurement instruments were ranked for: Cognitive abilities; Functional abilities/dependency; Behavioural and neuropsychiatric symptoms; Patient quality of life (QoL); Caregiver QoL; Healthcare and treatment-related outcomes; Medical investigations; Disease-related life events; and Global outcomes. DISCUSSION: This work provides indications on the domains and ideal pertinent measurement instruments that clinicians may wish to use to follow patients with cognitive impairment. More work is needed to develop instruments that are more feasible in the context of the constraints of clinical routine.


Asunto(s)
Enfermedad de Alzheimer , Humanos , Enfermedad de Alzheimer/terapia , Enfermedad de Alzheimer/diagnóstico , Calidad de Vida , Consenso , Técnica Delphi , Evaluación de Resultado en la Atención de Salud
9.
Alzheimers Dement ; 19(5): 1729-1741, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36209379

RESUMEN

INTRODUCTION: Etiological diagnosis of neurocognitive disorders of middle-old age relies on biomarkers, although evidence for their rational use is incomplete. A European task force is defining a diagnostic workflow where expert experience fills evidence gaps for biomarker validity and prioritization. We report methodology and preliminary results. METHODS: Using a Delphi consensus method supported by a systematic literature review, 22 delegates from 11 relevant scientific societies defined workflow assumptions. RESULTS: We extracted diagnostic accuracy figures from literature on the use of biomarkers in the diagnosis of main forms of neurocognitive disorders. Supported by this evidence, panelists defined clinical setting (specialist outpatient service), application stage (MCI-mild dementia), and detailed pre-assessment screening (clinical-neuropsychological evaluations, brain imaging, and blood tests). DISCUSSION: The Delphi consensus on these assumptions set the stage for the development of the first pan-European workflow for biomarkers' use in the etiological diagnosis of middle-old age neurocognitive disorders at MCI-mild dementia stages. HIGHLIGHTS: Rational use of biomarkers in neurocognitive disorders lacks consensus in Europe. A consensus of experts will define a workflow for the rational use of biomarkers. The diagnostic workflow will be patient-centered and based on clinical presentation. The workflow will be updated as new evidence accrues.


Asunto(s)
Disfunción Cognitiva , Demencia , Humanos , Disfunción Cognitiva/diagnóstico , Consenso , Sensibilidad y Especificidad , Demencia/diagnóstico , Biomarcadores
10.
Neuroimage ; 254: 119029, 2022 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-35231632

RESUMEN

Virtual dissection of white matter (WM) using diffusion MRI tractography is confounded by its poor reproducibility. Despite the increased adoption of advanced reconstruction models, early region-of-interest driven protocols based on diffusion tensor imaging (DTI) remain the dominant reference for virtual dissection protocols. Here we bridge this gap by providing a comprehensive description of typical WM anatomy reconstructed using a reproducible automated subject-specific parcellation-based approach based on probabilistic constrained-spherical deconvolution (CSD) tractography. We complement this with a WM template in MNI space comprising 68 bundles, including all associated anatomical tract selection labels and associated automated workflows. Additionally, we demonstrate bundle inter- and intra-subject variability using 40 (20 test-retest) datasets from the human connectome project (HCP) and 5 sessions with varying b-values and number of b-shells from the single-subject Multiple Acquisitions for Standardization of Structural Imaging Validation and Evaluation (MASSIVE) dataset. The most reliably reconstructed bundles were the whole pyramidal tracts, primary corticospinal tracts, whole superior longitudinal fasciculi, frontal, parietal and occipital segments of the corpus callosum and middle cerebellar peduncles. More variability was found in less dense bundles, e.g., the fornix, dentato-rubro-thalamic tract (DRTT), and premotor pyramidal tract. Using the DRTT as an example, we show that this variability can be reduced by using a higher number of seeding attempts. Overall inter-session similarity was high for HCP test-retest data (median weighted-dice = 0.963, stdev = 0.201 and IQR = 0.099). Compared to the HCP-template bundles there was a high level of agreement for the HCP test-retest data (median weighted-dice = 0.747, stdev = 0.220 and IQR = 0.277) and for the MASSIVE data (median weighted-dice = 0.767, stdev = 0.255 and IQR = 0.338). In summary, this WM atlas provides an overview of the capabilities and limitations of automated subject-specific probabilistic CSD tractography for mapping white matter fasciculi in healthy adults. It will be most useful in applications requiring a reproducible parcellation-based dissection protocol, and as an educational resource for applied neuroimaging and clinical professionals.


Asunto(s)
Conectoma , Sustancia Blanca , Adulto , Imagen de Difusión por Resonancia Magnética , Imagen de Difusión Tensora/métodos , Humanos , Reproducibilidad de los Resultados , Sustancia Blanca/diagnóstico por imagen
11.
Eur J Nucl Med Mol Imaging ; 49(13): 4580-4588, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35852556

RESUMEN

PURPOSE: Neurofibrillary tangles (NFTs) in Alzheimer's disease can be accurately quantified in vivo using [18F]MK-6240 PET. Short-term [18F]MK-6240 test-retest (TRT) is about 6%, but also long-term stability of cerebral uptake is of importance for longitudinal studies. Furthermore, although there is very little cerebral off-target binding, [18F]MK-6240 shows variable extracerebral uptake (ECU) assumed to represent off-target binding to leptomeningeal melanocytes. Here, we examined 6-month TRT of [18F]MK-6240 in healthy controls (HC) and investigated ECU in HC and patients with amnestic mild cognitive impairment (aMCI) with up to 2 years of follow-up. We also explored demographic factors that may be associated to ECU, including age, sex, education, smoking, and disease status. METHODS: A total cohort of 40 HC (57 ± 19 years, 21F/19 M) and 24 aMCI (72 ± 8 years, 14F/10 M) underwent baseline [18F]MK-6240 PET-MR (GE Signa), 90-120 min post injection. [18F]MK-6240 was quantified by standardized uptake value ratios (SUVR) in predefined volumes-of-interest relative to the cerebellar cortex. Ten HC (56 ± 12 years, 8F/2 M) underwent a 6-month follow-up [18F]MK-6240 to assess TRT. Also, 10 aMCI (72 ± 6 years, 5F/5 M) underwent a 2-year follow-up [18F]MK-6240 PET-MR. Longitudinal changes in ECU were assessed in both cohorts. ECU was quantified as the mean SUVR of the skull parcel (FreeSurfer 6.0) that includes the meninges. RESULTS: The mean gray matter [18F]MK-6240 SUVR TRT and absolute TRT in HC were 1.6 ± 3.4% and 2.4 ± 2.8%, respectively. We found no significant 6-month or 2-year differences in ECU in HC (4.4 ± 20%) and aMCI (7.9 ± 19%), respectively. In the total cohort, ECU was significantly correlated to age (rs = - 0.48; p < 0.0001), and a multivariate analysis also showed sex differences (higher ECU in women). CONCLUSION: [18F]MK-6240 shows excellent 6-month TRT, which confirms its suitability for quantification of longitudinal NFT changes. The ECU of [18F]MK-6240 is variable between subjects, influenced by age and sex, but remains stable within subjects over a 2-year time period.


Asunto(s)
Enfermedad de Alzheimer , Disfunción Cognitiva , Humanos , Femenino , Masculino , Tomografía de Emisión de Positrones , Disfunción Cognitiva/diagnóstico por imagen , Disfunción Cognitiva/metabolismo , Ovillos Neurofibrilares/metabolismo , Isoquinolinas , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/metabolismo
12.
Am J Geriatr Psychiatry ; 30(12): 1283-1294, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-35667960

RESUMEN

OBJECTIVE: Electroconvulsive therapy (ECT) is the most effective treatment for late-life depression (LLD). Research addressing long-term outcome following an acute course of ECT for LLD is limited. We aimed to describe relapse, cognitive impairment and survival 5 years after a treatment with ECT for severe LLD, and assess the association of clinical characteristics with all three outcome measures. METHODS: This cohort study was part of the Mood Disorders in Elderly treated with ECT (MODECT) study, which included patients aged 55 years and older with major depressive disorder. Data regarding clinical course, cognitive impairment and mortality were collected 5 years after the index ECT course. We used multivariable Cox proportional hazards models and logistic regression models to assess the association of clinical characteristics with relapse and survival, and cognitive impairment, respectively. RESULTS: We studied 110 patients with a mean age of 72.9 years. 67.1% of patients who showed response at the end of the index ECT course relapsed, and the included clinical characteristics were not significantly associated with the risk of relapse. 38.8% of patients with available data showed cognitive impairment at five-year follow-up. 27.5% were deceased; higher age and a higher number of previous psychiatric admissions were significantly associated with increased risk of mortality. CONCLUSIONS: Five-year outcome after a course of ECT for severe LLD seems to be in line with long-term outcome following other acute treatments for severe LLD in terms of relapse, cognitive impairment and survival. Additional studies aimed at improving long-term outcome in severe LLD are warranted.


Asunto(s)
Trastorno Depresivo Mayor , Terapia Electroconvulsiva , Anciano , Humanos , Terapia Electroconvulsiva/efectos adversos , Trastorno Depresivo Mayor/terapia , Estudios de Cohortes , Depresión/terapia , Estudios de Seguimiento , Resultado del Tratamiento , Recurrencia
13.
Neuroimage ; 232: 117877, 2021 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-33639258

RESUMEN

RATIONALE: 11C-UCB-J binds to synaptic vesicle glycoprotein 2A, a protein ubiquitously expressed in presynaptic nerve terminals, and can therefore serve as in vivo proxy of synaptic density. There are discrepancies in postmortem data on stability of synaptic density with healthy aging. In this study, healthy aging and sex as potential modifiers of 11C-UCB-J binding were investigated in healthy volunteers over 7 adult decades, assuming that the number of SV2A vesicles per synapse is not influenced by age or sex. METHODS: 80 healthy volunteers underwent 11C-UCB-J PET and structural T1 and T2 MR imaging. Grey matter changes with aging were firstly evaluated by voxel-based morphometry (VBM). Parametric 11C-UCB-J standardized uptake value ratio (SUVR) images were calculated using the centrum semiovale as reference tissue. To correct for atrophy-related partial volume effects, a region-based voxel-wise type partial volume correction (PVC) was applied in FreeSurfer. The correlations of 11C-UCB-J binding with age and with sex were investigated by a voxel-based and volume-of-interest (VOI)-based approach, and with and without PVC to assess the contribution of underlying morphology changes upon aging. RESULTS: Full results were available for 78 participants (19-85y; 33 M/45 F). VBM grey matter concentration changes with aging were most predominant in the perisylvian and frontal regions. After PVC, no significantly decreased 11C-UCB-J SUVR with aging was found in the voxel-based analysis, whereas the VOI-based analysis showed a slight decrease in the caudate nucleus (-1.7% decrease per decade, p= 0.0025) only. There was no association between sex and 11C-UCB-J SUVR, nor an interaction between aging and sex for this parameter. CONCLUSION: In vivo, PET using 11C-UCB-J does not support a cortical decrease of synaptic density with aging, whereas subcortically a small effect with aging in the caudate nucleus was observed. In addition, no association between synaptic density and sex was detected, which allows pooling of datasets of both sexes.


Asunto(s)
Encéfalo/metabolismo , Envejecimiento Saludable/metabolismo , Tomografía de Emisión de Positrones/métodos , Piridinas/metabolismo , Pirrolidinonas/metabolismo , Sinapsis/metabolismo , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Encéfalo/diagnóstico por imagen , Radioisótopos de Carbono/metabolismo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores Sexuales , Adulto Joven
14.
Acta Neuropathol ; 141(2): 173-192, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33427938

RESUMEN

In Alzheimer's disease (AD), tau-protein undergoes a multi-step process involving the transition from a natively unfolded monomer to large, aggregated structures such as neurofibrillary tangles (NFTs). However, it is not yet clear which events initiate the early preclinical phase of AD tauopathy and whether they have impact on the propagation of tau pathology in later disease stages. To address this question, we analyzed the distribution of tau species phosphorylated at T231, S396/S404 and S202/T205, conformationally modified at the MC1 epitope and fibrillary tau detected by the Gallyas method (Gallyas-tau), in the brains of 15 symptomatic and 20 asymptomatic cases with AD pathology as well as of 19 nonAD cases. As initial tau lesions, we identified phosphorylated-T231-tau diffusely distributed within the somatodendritic compartment (IC-tau) and phosphorylated-S396/pS404-tau in axonal lesions of the white matter and in the neuropil (IN-tau). The subcellular localization of pT231-tau in the cell body and pS396/pS404-tau in the presynapse was confirmed in hP301L mutant Drosophila larvae. Phosphorylated-S202/T205-tau, MC1-tau and Gallyas-tau were negative for these lesions. IC- and IN-tau were observed in all analyzed regions of the human brain, including early affected regions in nonAD cases (entorhinal cortex) and late affected regions in symptomatic AD cases (cerebellum), indicating that tau pathology initiation follows similar processes when propagating into previously unaffected regions. Furthermore, a sequence of AD-related maturation of tau-aggregates was observed, initiated by the appearance of IC- and IN-tau, followed by the formation of pretangles exhibiting pT231-tau, pS396/pS404-tau and pS202/pT205-tau, then by MC1-conformational tau, and, finally, by the formation of Gallyas-positive NFTs. Since cases classified as nonAD [Braak NFT stages < I (including a-1b)] already showed IC- and IN-tau, our findings suggest that these lesions are a prerequisite for the development of AD.


Asunto(s)
Enfermedad de Alzheimer/patología , Citoplasma/patología , Ovillos Neurofibrilares/patología , Sinapsis/patología , Tauopatías/patología , Proteínas tau/metabolismo , Anciano , Anciano de 80 o más Años , Animales , Autopsia , Cerebelo/química , Cerebelo/patología , Citoplasma/química , Drosophila , Corteza Entorrinal/química , Corteza Entorrinal/patología , Femenino , Humanos , Inmunohistoquímica , Larva , Masculino , Persona de Mediana Edad , Ovillos Neurofibrilares/química , Fosforilación , Conformación Proteica , Sinapsis/química
15.
J Psychiatry Neurosci ; 46(4): E418-E426, 2021 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-34223741

RESUMEN

Background: Obesity is a frequent somatic comorbidity of major depression, and it has been associated with worse clinical outcomes and brain structural abnormalities. Converging evidence suggests that electroconvulsive therapy (ECT) induces both clinical improvements and increased subcortical grey matter volume in patients with depression. However, it remains unknown whether increased body weight modulates the clinical response and structural neuroplasticity that occur with ECT. Methods: To address this question, we conducted a longitudinal investigation of structural MRI data from the Global ECT-MRI Research Collaboration (GEMRIC) in 223 patients who were experiencing a major depressive episode (10 scanning sites). Structural MRI data were acquired before and after ECT, and we assessed change in subcortical grey matter volume using FreeSurfer and Quarc. Results: Higher body mass index (BMI) was associated with a significantly lower increase in subcortical grey matter volume following ECT. We observed significant negative associations between BMI and change in subcortical grey matter volume, with pronounced effects in the thalamus and putamen, where obese participants showed increases in grey matter volume that were 43.3% and 49.6%, respectively, of the increases found in participants with normal weight. As well, BMI significantly moderated the association between subcortical grey matter volume change and clinical response to ECT. We observed no significant association between BMI and clinical response to ECT. Limitations: Because only baseline BMI values were available, we were unable to study BMI changes during ECT and their potential association with clinical and grey matter volume change. Conclusion: Future studies should take into account the relevance of body weight as a modulator of structural neuroplasticity during ECT treatment and aim to further explore the functional relevance of this novel finding.


Asunto(s)
Peso Corporal , Encéfalo/patología , Trastorno Depresivo Mayor/patología , Trastorno Depresivo Mayor/terapia , Terapia Electroconvulsiva , Sustancia Gris/patología , Encéfalo/diagnóstico por imagen , Trastorno Depresivo Mayor/diagnóstico por imagen , Femenino , Sustancia Gris/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad
16.
J Geriatr Psychiatry Neurol ; 34(1): 21-28, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32036772

RESUMEN

OBJECTIVE: Apathy symptoms are defined as a lack of interest and motivation. Patients with late-life depression (LLD) also suffer from lack of interest and motivation and previous studies have linked apathy to vascular white matter hyperintensities (WMH) of the brain in depressed and nondepressed patients. The aim of this study was to investigate the relationship between apathy symptoms, depressive symptoms, and WMH in LLD. We hypothesize that late-onset depression (LOD; first episode of depression after 55 years of age) is associated with WMH and apathy symptoms. METHODS: Apathy scores were collected for 87 inpatients diagnosed with LLD. Eighty patients underwent brain magnetic resonance imaging. Associations between depressive and apathy symptoms and WMH were analyzed using linear regression. RESULTS: All 3 subdomains of the 10-item Montgomery-Åsberg Depression Rating Scale correlated significantly with the apathy scale score (all P < .05). In the total sample, apathy nor depressive symptoms were related to specific WMH. In LOD only, periventricular WMH were associated with depression severity (ß = 5.21, P = .04), while WMH in the left infratentorial region were associated with apathy symptoms (ß coefficient = 5.89, P = .03). CONCLUSION: Apathy and depressive symptoms are highly overlapping in the current cohort of older patients with severe LLD, leading to the hypothesis that apathy symptoms are part of depressive symptoms in the symptom profile of older patients with severe LLD. Neither apathy nor depressive symptoms were related to WMH, suggesting that radiological markers of cerebrovascular disease, such as WMH, may not be useful in predicting these symptoms in severe LLD.


Asunto(s)
Apatía , Depresión/patología , Imagen por Resonancia Magnética/métodos , Calidad de Vida , Sustancia Blanca/diagnóstico por imagen , Anciano , Anciano de 80 o más Años , Encéfalo/irrigación sanguínea , Encéfalo/patología , Depresión/epidemiología , Trastorno Depresivo/patología , Evaluación Geriátrica , Humanos , Enfermedades de Inicio Tardío , Masculino , Persona de Mediana Edad , Neuroimagen , Escalas de Valoración Psiquiátrica , Índice de Severidad de la Enfermedad , Sustancia Blanca/irrigación sanguínea , Sustancia Blanca/patología
17.
Brain ; 143(6): 1632-1650, 2020 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-32129844

RESUMEN

The behavioural variant of frontotemporal dementia (bvFTD) is a frequent cause of early-onset dementia. The diagnosis of bvFTD remains challenging because of the limited accuracy of neuroimaging in the early disease stages and the absence of molecular biomarkers, and therefore relies predominantly on clinical assessment. BvFTD shows significant symptomatic overlap with non-degenerative primary psychiatric disorders including major depressive disorder, bipolar disorder, schizophrenia, obsessive-compulsive disorder, autism spectrum disorders and even personality disorders. To date, ∼50% of patients with bvFTD receive a prior psychiatric diagnosis, and average diagnostic delay is up to 5-6 years from symptom onset. It is also not uncommon for patients with primary psychiatric disorders to be wrongly diagnosed with bvFTD. The Neuropsychiatric International Consortium for Frontotemporal Dementia was recently established to determine the current best clinical practice and set up an international collaboration to share a common dataset for future research. The goal of the present paper was to review the existing literature on the diagnosis of bvFTD and its differential diagnosis with primary psychiatric disorders to provide consensus recommendations on the clinical assessment. A systematic literature search with a narrative review was performed to determine all bvFTD-related diagnostic evidence for the following topics: bvFTD history taking, psychiatric assessment, clinical scales, physical and neurological examination, bedside cognitive tests, neuropsychological assessment, social cognition, structural neuroimaging, functional neuroimaging, CSF and genetic testing. For each topic, responsible team members proposed a set of minimal requirements, optimal clinical recommendations, and tools requiring further research or those that should be developed. Recommendations were listed if they reached a ≥ 85% expert consensus based on an online survey among all consortium participants. New recommendations include performing at least one formal social cognition test in the standard neuropsychological battery for bvFTD. We emphasize the importance of 3D-T1 brain MRI with a standardized review protocol including validated visual atrophy rating scales, and to consider volumetric analyses if available. We clarify the role of 18F-fluorodeoxyglucose PET for the exclusion of bvFTD when normal, whereas non-specific regional metabolism abnormalities should not be over-interpreted in the case of a psychiatric differential diagnosis. We highlight the potential role of serum or CSF neurofilament light chain to differentiate bvFTD from primary psychiatric disorders. Finally, based on the increasing literature and clinical experience, the consortium determined that screening for C9orf72 mutation should be performed in all possible/probable bvFTD cases or suspected cases with strong psychiatric features.


Asunto(s)
Demencia Frontotemporal/diagnóstico , Trastornos Mentales/diagnóstico , Diagnóstico Tardío , Diagnóstico Diferencial , Femenino , Fluorodesoxiglucosa F18 , Humanos , Imagen por Resonancia Magnética , Masculino , Neuroimagen , Examen Neurológico , Pruebas Neuropsicológicas , Tomografía de Emisión de Positrones
18.
BMC Psychiatry ; 21(1): 64, 2021 01 28.
Artículo en Inglés | MEDLINE | ID: mdl-33509135

RESUMEN

BACKGROUND: Major depressive disorders rank in the top ten causes of ill health in all but four countries worldwide and are the leading cause of years lived with disability in Europe (WHO). Recent research suggests that neurodegenerative pathology may contribute to the development of late-life depression (LLD) in a sub-group of patients and represent a target for prevention and early diagnosis. In parallel, electroconvulsive therapy (ECT), which is the most effective treatment for severe LLD, has been associated with significant brain structural changes. In both LLD and ECT hippocampal volume change plays a central role; however, the neurobiological mechanism underlying it and its relevance for clinical outcomes remain unresolved. METHODS: This is a monocentric, clinical cohort study with a cross-sectional arm evaluating PET-MR imaging and behavioural measures in 64 patients with LLD compared to 64 healthy controls, and a longitudinal arm evaluating the same imaging and behavioural measures after 10 ECT sessions in 20 patients receiving ECT as part of their normal clinical management. Triple tracer PET-MRI data will be used to measure: hippocampal volume (high resolution MRI), synaptic density using [11C]UCB-J, which targets the Synaptic Vesicle Glycoprotein 2A receptor, tau pathology using [18F]MK-6240, and cerebral amyloid using [18F]-Flutemetamol, which targets beta-amyloid neuritic plaques in the brain. Additional MRI measures and ultrasound will assess cerebral vascular structure and brain connectivity. Formal clinical and neuropsychological assessments will be conducted alongside experience sampling and physiological monitoring to assess mood, stress, cognition and psychomotor function. DISCUSSION: The main aim of the study is to identify the origin and consequences of hippocampal volume differences in LLD by investigating how biomarkers of pathological ageing contribute to medial temporal lobe pathology. Studying how synaptic density, tau, amyloid and vascular pathology relate to neuropsychological, psychomotor function, stress and ECT, will increase our pathophysiological understanding of the in vivo molecular, structural and functional alterations occurring in depression and what effect this has on clinical outcome. It may also lead to improvements in the differential diagnosis of depression and dementia yielding earlier, more optimal, cost-effective clinical management. Finally, it will improve our understanding of the neurobiological mechanism of ECT. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03849417 , 21/2/2019.


Asunto(s)
Trastorno Depresivo Mayor , Terapia Electroconvulsiva , Envejecimiento , Biomarcadores , Encéfalo/diagnóstico por imagen , Estudios de Cohortes , Estudios Transversales , Depresión , Europa (Continente) , Humanos , Imagen por Resonancia Magnética
19.
Aging Ment Health ; 25(1): 170-178, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-31729244

RESUMEN

OBJECTIVES: To explore what sources of well-being are rated meaningful by older adults in residential care and how they are related to two important well-being outcomes. METHOD: Two cross-sectional questionnaire studies were conducted in a sample of care residents without cognitive disability (n = 329) and with Alzheimer's disease (n = 104). Structural equation modelling was used to test a hypothesized and exploratory model of different sources as predictors of presence of meaning in life (POM) and satisfaction with life (SWL). RESULTS: Family and Health were rated most meaningful by residents with and without dementia. In both studies, the hypothesized model showed adequate fit with the data. For cognitively intact residents, Personal Growth, Spirituality/Religion, and Interpersonal Relationships predicted POM, while Family and Leisure predicted SWL. Exploratory testing identified Leisure as a possible additional predictor of POM. For residents with Alzheimer's disease, Personal Growth and Society/Community predicted POM, while Family predicted SWL. CONCLUSION: For older adults in residential care, many sources of well-being remain highly meaningful and some are directly related to the experience of meaning and life satisfaction. Both for residents with and without dementia, continued or increased investment in moments that foster personal growth and family relationships might be especially valuable.


Asunto(s)
Enfermedad de Alzheimer , Satisfacción Personal , Anciano , Estudios Transversales , Humanos , Casas de Salud , Calidad de Vida
20.
Cancer ; 126(18): 4246-4255, 2020 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-32639592

RESUMEN

BACKGROUND: Many breast cancer survivors suffer from cognitive complaints after cancer treatment, affecting their quality of life. The objective of this pilot study was to investigate the effect of a blended-care mindfulness-based intervention (MBI) on chemotherapy-related cognitive impairment and functional brain changes. Furthermore, correlations between changes in cognitive functioning and self-reported behavioral factors were investigated. METHODS: Breast cancer survivors (n = 33) who reported cognitive impairment were randomly allocated to a mindfulness condition (n = 18) or a waitlist control condition (n = 15). Patients completed questionnaires on cognitive impairment, emotional distress, and fatigue; neuropsychological tests; and resting-state functional magnetic resonance imaging before the start of MBI (time 1 [T1]), immediately after the completion of an 8-week MBI program (T2), and 3 months postintervention (T3). Resting-state functional connectivity was estimated in the default mode network, the dorsal and salience attention networks, and the frontoparietal network. Mixed model repeated-measures analysis was performed to test the intervention effect. RESULTS: Patients in the mindfulness condition exhibited significantly higher connectivity between the dorsal and salience attention networks after the mindfulness intervention compared with those in the control condition. MBI participants also had reduced subjective cognitive impairment, emotional distress, and fatigue. No intervention effect was observed on neurocognitive tests. CONCLUSIONS: MBI may induce functional brain changes in networks related to attention and may have a positive effect on subjective measures of cognitive impairment in breast cancer survivors. Therefore, MBI could be a suitable intervention to improve quality of life in this population and deserves further study in this context.


Asunto(s)
Disfunción Cognitiva/psicología , Imagen por Resonancia Magnética/métodos , Atención Plena/métodos , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Adulto Joven
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