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1.
Nature ; 625(7994): 345-351, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38057661

RESUMO

Frontotemporal lobar degeneration (FTLD) causes frontotemporal dementia (FTD), the most common form of dementia after Alzheimer's disease, and is often also associated with motor disorders1. The pathological hallmarks of FTLD are neuronal inclusions of specific, abnormally assembled proteins2. In the majority of cases the inclusions contain amyloid filament assemblies of TAR DNA-binding protein 43 (TDP-43) or tau, with distinct filament structures characterizing different FTLD subtypes3,4. The presence of amyloid filaments and their identities and structures in the remaining approximately 10% of FTLD cases are unknown but are widely believed to be composed of the protein fused in sarcoma (FUS, also known as translocated in liposarcoma). As such, these cases are commonly referred to as FTLD-FUS. Here we used cryogenic electron microscopy (cryo-EM) to determine the structures of amyloid filaments extracted from the prefrontal and temporal cortices of four individuals with FTLD-FUS. Surprisingly, we found abundant amyloid filaments of the FUS homologue TATA-binding protein-associated factor 15 (TAF15, also known as TATA-binding protein-associated factor 2N) rather than of FUS itself. The filament fold is formed from residues 7-99 in the low-complexity domain (LCD) of TAF15 and was identical between individuals. Furthermore, we found TAF15 filaments with the same fold in the motor cortex and brainstem of two of the individuals, both showing upper and lower motor neuron pathology. The formation of TAF15 amyloid filaments with a characteristic fold in FTLD establishes TAF15 proteinopathy in neurodegenerative disease. The structure of TAF15 amyloid filaments provides a basis for the development of model systems of neurodegenerative disease, as well as for the design of diagnostic and therapeutic tools targeting TAF15 proteinopathy.


Assuntos
Degeneração Lobar Frontotemporal , Fatores Associados à Proteína de Ligação a TATA , Humanos , Amiloide/química , Amiloide/metabolismo , Amiloide/ultraestrutura , Tronco Encefálico/metabolismo , Tronco Encefálico/patologia , Microscopia Crioeletrônica , Demência Frontotemporal/etiologia , Demência Frontotemporal/metabolismo , Demência Frontotemporal/patologia , Degeneração Lobar Frontotemporal/complicações , Degeneração Lobar Frontotemporal/metabolismo , Degeneração Lobar Frontotemporal/patologia , Córtex Motor/metabolismo , Córtex Motor/patologia , Neurônios Motores/metabolismo , Neurônios Motores/patologia , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/patologia , Fatores Associados à Proteína de Ligação a TATA/química , Fatores Associados à Proteína de Ligação a TATA/metabolismo , Fatores Associados à Proteína de Ligação a TATA/ultraestrutura , Lobo Temporal/metabolismo , Lobo Temporal/patologia
2.
Cell ; 159(7): 1511-23, 2014 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-25525873

RESUMO

Alternative splicing (AS) generates vast transcriptomic and proteomic complexity. However, which of the myriad of detected AS events provide important biological functions is not well understood. Here, we define the largest program of functionally coordinated, neural-regulated AS described to date in mammals. Relative to all other types of AS within this program, 3-15 nucleotide "microexons" display the most striking evolutionary conservation and switch-like regulation. These microexons modulate the function of interaction domains of proteins involved in neurogenesis. Most neural microexons are regulated by the neuronal-specific splicing factor nSR100/SRRM4, through its binding to adjacent intronic enhancer motifs. Neural microexons are frequently misregulated in the brains of individuals with autism spectrum disorder, and this misregulation is associated with reduced levels of nSR100. The results thus reveal a highly conserved program of dynamic microexon regulation associated with the remodeling of protein-interaction networks during neurogenesis, the misregulation of which is linked to autism.


Assuntos
Processamento Alternativo , Transtornos Globais do Desenvolvimento Infantil/patologia , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Animais , Transtornos Globais do Desenvolvimento Infantil/metabolismo , Humanos , Camundongos , Modelos Moleculares , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Neurogênese , Domínios e Motivos de Interação entre Proteínas , Análise de Sequência de RNA , Lobo Temporal/patologia
3.
Brain ; 147(7): 2483-2495, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38701342

RESUMO

Network neuroscience offers a unique framework to understand the organizational principles of the human brain. Despite recent progress, our understanding of how the brain is modulated by focal lesions remains incomplete. Resection of the temporal lobe is the most effective treatment to control seizures in pharmaco-resistant temporal lobe epilepsy (TLE), making this syndrome a powerful model to study lesional effects on network organization in young and middle-aged adults. Here, we assessed the downstream consequences of a focal lesion and its surgical resection on the brain's structural connectome, and explored how this reorganization relates to clinical variables at the individual patient level. We included adults with pharmaco-resistant TLE (n = 37) who underwent anterior temporal lobectomy between two imaging time points, as well as age- and sex-matched healthy controls who underwent comparable imaging (n = 31). Core to our analysis was the projection of high-dimensional structural connectome data-derived from diffusion MRI tractography from each subject-into lower-dimensional gradients. We then compared connectome gradients in patients relative to controls before surgery, tracked surgically-induced connectome reconfiguration from pre- to postoperative time points, and examined associations to patient-specific clinical and imaging phenotypes. Before surgery, individuals with TLE presented with marked connectome changes in bilateral temporo-parietal regions, reflecting an increased segregation of the ipsilateral anterior temporal lobe from the rest of the brain. Surgery-induced connectome reorganization was localized to this temporo-parietal subnetwork, but primarily involved postoperative integration of contralateral regions with the rest of the brain. Using a partial least-squares analysis, we uncovered a latent clinical imaging signature underlying this pre- to postoperative connectome reorganization, showing that patients who displayed postoperative integration in bilateral fronto-occipital cortices also had greater preoperative ipsilateral hippocampal atrophy, lower seizure frequency and secondarily generalized seizures. Our results bridge the effects of focal brain lesions and their surgical resections with large-scale network reorganization and interindividual clinical variability, thus offering new avenues to examine the fundamental malleability of the human brain.


Assuntos
Lobectomia Temporal Anterior , Conectoma , Epilepsia do Lobo Temporal , Lobo Temporal , Humanos , Feminino , Masculino , Adulto , Epilepsia do Lobo Temporal/cirurgia , Epilepsia do Lobo Temporal/fisiopatologia , Epilepsia do Lobo Temporal/diagnóstico por imagem , Epilepsia do Lobo Temporal/patologia , Lobo Temporal/patologia , Lobo Temporal/cirurgia , Lobo Temporal/diagnóstico por imagem , Lobectomia Temporal Anterior/métodos , Pessoa de Meia-Idade , Adulto Jovem , Imagem de Tensor de Difusão , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/patologia , Epilepsia Resistente a Medicamentos/cirurgia , Epilepsia Resistente a Medicamentos/diagnóstico por imagem , Epilepsia Resistente a Medicamentos/fisiopatologia , Epilepsia Resistente a Medicamentos/patologia
4.
Cereb Cortex ; 34(3)2024 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-38521993

RESUMO

Alzheimer's disease (AD) and mild cognitive impairment (MCI) both show abnormal resting-state functional connectivity (rsFC) of default mode network (DMN), but it is unclear to what extent these abnormalities are shared. Therefore, we performed a comprehensive meta-analysis, including 31 MCI studies and 20 AD studies. MCI patients, compared to controls, showed decreased within-DMN rsFC in bilateral medial prefrontal cortex/anterior cingulate cortex (mPFC/ACC), precuneus/posterior cingulate cortex (PCC), right temporal lobes, and left angular gyrus and increased rsFC between DMN and left inferior temporal gyrus. AD patients, compared to controls, showed decreased rsFC within DMN in bilateral mPFC/ACC and precuneus/PCC and between DMN and left inferior occipital gyrus and increased rsFC between DMN and right dorsolateral prefrontal cortex. Conjunction analysis showed shared decreased rsFC in mPFC/ACC and precuneus/PCC. Compared to MCI, AD had decreased rsFC in left precuneus/PCC and between DMN and left inferior occipital gyrus and increased rsFC in right temporal lobes. MCI and AD share a decreased within-DMN rsFC likely underpinning episodic memory deficits and neuropsychiatric symptoms, but differ in DMN rsFC alterations likely related to impairments in other cognitive domains such as language, vision, and execution. This may throw light on neuropathological mechanisms in these two stages of dementia.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Doença de Alzheimer/diagnóstico por imagem , Rede de Modo Padrão , Disfunção Cognitiva/patologia , Giro do Cíngulo , Lobo Temporal/patologia , Imageamento por Ressonância Magnética , Encéfalo , Mapeamento Encefálico
5.
Cereb Cortex ; 34(8)2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39123309

RESUMO

The functional importance of the anterior temporal lobes (ATLs) has come to prominence in two active, albeit unconnected literatures-(i) face recognition and (ii) semantic memory. To generate a unified account of the ATLs, we tested the predictions from each literature and examined the effects of bilateral versus unilateral ATL damage on face recognition, person knowledge, and semantic memory. Sixteen people with bilateral ATL atrophy from semantic dementia (SD), 17 people with unilateral ATL resection for temporal lobe epilepsy (TLE; left = 10, right = 7), and 14 controls completed tasks assessing perceptual face matching, person knowledge and general semantic memory. People with SD were impaired across all semantic tasks, including person knowledge. Despite commensurate total ATL damage, unilateral resection generated mild impairments, with minimal differences between left- and right-ATL resection. Face matching performance was largely preserved but slightly reduced in SD and right TLE. All groups displayed the familiarity effect in face matching; however, it was reduced in SD and right TLE and was aligned with the level of item-specific semantic knowledge in all participants. We propose a neurocognitive framework whereby the ATLs underpin a resilient bilateral representation system that supports semantic memory, person knowledge and face recognition.


Assuntos
Epilepsia do Lobo Temporal , Reconhecimento Facial , Semântica , Lobo Temporal , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Lobo Temporal/cirurgia , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/patologia , Adulto , Reconhecimento Facial/fisiologia , Epilepsia do Lobo Temporal/cirurgia , Epilepsia do Lobo Temporal/psicologia , Epilepsia do Lobo Temporal/fisiopatologia , Reconhecimento Psicológico/fisiologia , Lateralidade Funcional/fisiologia , Testes Neuropsicológicos , Memória/fisiologia , Idoso , Face
6.
J Cogn Neurosci ; 36(10): 2251-2267, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39106171

RESUMO

Understanding the neurobiology of semantic knowledge is a major goal of cognitive neuroscience. Taxonomic and thematic semantic knowledge are represented differently within the brain's conceptual networks, but the specific neural mechanisms remain unclear. Some neurobiological models propose that the anterior temporal lobe is an important hub for taxonomic knowledge, whereas the TPJ is especially involved in the representation of thematic knowledge. However, recent studies have provided divergent evidence. In this context, we investigated the neural correlates of taxonomic and thematic confrontation naming errors in 79 people with aphasia. We used three complementary lesion-symptom mapping (LSM) methods to investigate how structure and function in both spared and impaired brain regions relate to taxonomic and thematic naming errors. Voxel-based LSM mapped brain damage, activation-based LSM mapped BOLD signal in surviving tissue, and network-based LSM mapped white matter subnetwork integrity to error type. Voxel- and network-based lesion symptom mapping provided converging evidence that damage/disruption of the left mid-to-anterior temporal lobe was associated with a greater proportion of thematic naming errors. Activation-based lesion symptom mapping revealed that higher BOLD signal in the left anterior temporal lobe during an in-house naming task was associated with a greater proportion of taxonomic errors on the Philadelphia Naming Test administered outside of the scanner. A lower BOLD signal in the bilateral angular gyrus, precuneus, and right inferior frontal cortex was associated with a greater proportion of taxonomic errors. These findings provide novel evidence that damage to the anterior temporal lobe is especially related to thematic naming errors.


Assuntos
Afasia , Mapeamento Encefálico , Imageamento por Ressonância Magnética , Acidente Vascular Cerebral , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/fisiopatologia , Afasia/fisiopatologia , Afasia/diagnóstico por imagem , Afasia/patologia , Idoso , Semântica , Adulto , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/fisiopatologia , Lobo Temporal/patologia , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Encéfalo/patologia
7.
Hippocampus ; 34(4): 197-203, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38189156

RESUMO

Tau pathology accumulates in the perirhinal cortex (PRC) of the medial temporal lobe (MTL) during the earliest stages of the Alzheimer's disease (AD), appearing decades before clinical diagnosis. Here, we leveraged perceptual discrimination tasks that target PRC function to detect subtle cognitive impairment even in nominally healthy older adults. Older adults who did not have a clinical diagnosis or subjective memory complaints were categorized into "at-risk" (score <26; n = 15) and "healthy" (score ≥26; n = 23) groups based on their performance on the Montreal Cognitive Assessment. The task included two conditions known to recruit the PRC: faces and complex objects (greebles). A scene condition, known to recruit the hippocampus, and a size control condition that does not rely on the MTL were also included. Individuals in the at-risk group were less accurate than those in the healthy group for discriminating greebles. Performance on either the face or size control condition did not predict group status above and beyond that of the greeble condition. Visual discrimination tasks that are sensitive to PRC function may detect early cognitive decline associated with AD.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Idoso , Lobo Temporal/patologia , Hipocampo , Percepção Visual , Discriminação Psicológica , Doença de Alzheimer/patologia , Imageamento por Ressonância Magnética , Disfunção Cognitiva/patologia
8.
Hippocampus ; 34(5): 241-260, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38415962

RESUMO

The medial temporal lobe (MTL) cortex, located adjacent to the hippocampus, is crucial for memory and prone to the accumulation of certain neuropathologies such as Alzheimer's disease neurofibrillary tau tangles. The MTL cortex is composed of several subregions which differ in their functional and cytoarchitectonic features. As neuroanatomical schools rely on different cytoarchitectonic definitions of these subregions, it is unclear to what extent their delineations of MTL cortex subregions overlap. Here, we provide an overview of cytoarchitectonic definitions of the entorhinal and parahippocampal cortices as well as Brodmann areas (BA) 35 and 36, as provided by four neuroanatomists from different laboratories, aiming to identify the rationale for overlapping and diverging delineations. Nissl-stained series were acquired from the temporal lobes of three human specimens (two right and one left hemisphere). Slices (50 µm thick) were prepared perpendicular to the long axis of the hippocampus spanning the entire longitudinal extent of the MTL cortex. Four neuroanatomists annotated MTL cortex subregions on digitized slices spaced 5 mm apart (pixel size 0.4 µm at 20× magnification). Parcellations, terminology, and border placement were compared among neuroanatomists. Cytoarchitectonic features of each subregion are described in detail. Qualitative analysis of the annotations showed higher agreement in the definitions of the entorhinal cortex and BA35, while the definitions of BA36 and the parahippocampal cortex exhibited less overlap among neuroanatomists. The degree of overlap of cytoarchitectonic definitions was partially reflected in the neuroanatomists' agreement on the respective delineations. Lower agreement in annotations was observed in transitional zones between structures where seminal cytoarchitectonic features are expressed less saliently. The results highlight that definitions and parcellations of the MTL cortex differ among neuroanatomical schools and thereby increase understanding of why these differences may arise. This work sets a crucial foundation to further advance anatomically-informed neuroimaging research on the human MTL cortex.


Assuntos
Lobo Temporal , Humanos , Lobo Temporal/patologia , Neuroanatomia/métodos , Masculino , Giro Para-Hipocampal/patologia , Giro Para-Hipocampal/diagnóstico por imagem , Feminino , Idoso , Córtex Entorrinal/patologia , Córtex Entorrinal/anatomia & histologia , Laboratórios , Idoso de 80 Anos ou mais
9.
Hum Brain Mapp ; 45(5): e26562, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38590154

RESUMO

The goal of this study was to examine what happens to established associations between attention deficit hyperactivity disorder (ADHD) symptoms and cortical surface and thickness regions once we apply inverse probability of censoring weighting (IPCW) to address potential selection bias. Moreover, we illustrate how different factors that predict participation contribute to potential selection bias. Participants were 9- to 11-year-old children from the Generation R study (N = 2707). Cortical area and thickness were measured with magnetic resonance imaging (MRI) and ADHD symptoms with the Child Behavior Checklist. We examined how associations between ADHD symptoms and brain morphology change when we weight our sample back to either follow-up (ages 9-11), baseline (cohort at birth), or eligible (population of Rotterdam at time of recruitment). Weights were derived using IPCW or raking and missing predictors of participation used to estimate weights were imputed. Weighting analyses to baseline and eligible increased beta coefficients for the middle temporal gyrus surface area, as well as fusiform gyrus cortical thickness. Alternatively, the beta coefficient for the rostral anterior cingulate decreased. Removing one group of variables used for estimating weights resulted in the weighted regression coefficient moving closer to the unweighted regression coefficient. In addition, we found considerably different beta coefficients for most surface area regions and all thickness measures when we did not impute missing covariate data. Our findings highlight the importance of using inverse probability weighting (IPW) in the neuroimaging field, especially in the context of mental health-related research. We found that including all variables related to exposure-outcome in the IPW model and combining IPW with multiple imputations can help reduce bias. We encourage future psychiatric neuroimaging studies to define their target population, collect information on eligible but not included participants and use inverse probability of censoring weighting (IPCW) to reduce selection bias.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Criança , Recém-Nascido , Humanos , Viés de Seleção , Transtorno do Deficit de Atenção com Hiperatividade/patologia , Probabilidade , Viés , Lobo Temporal/patologia
10.
Hum Brain Mapp ; 45(15): e70054, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-39450487

RESUMO

Early stages of Alzheimer's disease (AD) are associated with volume reductions in specific subregions of the medial temporal lobe (MTL). Using a manual segmentation method-the Olsen-Amaral-Palombo (OAP) protocol-previous work in healthy older adults showed that reductions in grey matter volumes in MTL subregions were associated with lower scores on the Montreal Cognitive Assessment (MoCA), suggesting atrophy may occur prior to diagnosis of mild cognitive impairment, a condition that often progresses to AD. However, current "gold standard" manual segmentation methods are labour intensive and time consuming. Here, we examined the utility of Automatic Segmentation of Hippocampal Subfields (ASHS) to detect volumetric differences in MTL subregions of healthy older adults who varied in cognitive status as determined by the MoCA. We trained ASHS on the OAP protocol to create the ASHS-OAP atlas and then examined how well automated segmentation replicated manual segmentation. Volumetric measures obtained from the ASHS-OAP atlas were also contrasted against those from the ASHS-PMC atlas, a widely used atlas provided by the ASHS team. The pattern of volumetric results was similar between the ASHS-OAP atlas and manual segmentation for anterolateral entorhinal cortex and perirhinal cortex, suggesting that ASHS-OAP is a viable alternative to current manual segmentation methods for detecting group differences based on cognitive status. Although ASHS-OAP and ASHS-PMC produced varying volumes for most regions of interest, they both identified early signs of neurodegeneration in CA2/CA3/DG and identified marginal differences in entorhinal cortex. Our findings highlight the utility of automated segmentation methods but still underscore the need for a unified and harmonized MTL segmentation atlas.


Assuntos
Envelhecimento , Imageamento por Ressonância Magnética , Lobo Temporal , Humanos , Idoso , Feminino , Masculino , Imageamento por Ressonância Magnética/métodos , Envelhecimento/patologia , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/patologia , Hipocampo/diagnóstico por imagem , Hipocampo/patologia , Hipocampo/anatomia & histologia , Idoso de 80 Anos ou mais , Pessoa de Meia-Idade , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/patologia , Processamento de Imagem Assistida por Computador/métodos , Atlas como Assunto , Atrofia/patologia , Córtex Entorrinal/diagnóstico por imagem , Córtex Entorrinal/patologia , Córtex Entorrinal/anatomia & histologia , Testes de Estado Mental e Demência
11.
J Neurosci Res ; 102(9): e25385, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39305083

RESUMO

Astrocytes and microglia can adopt two distinct phenotypes in various pathological processes: neurotoxic A1/M1 and neuroprotective A2/M2. Recent evidence suggests that these cells play a significant role in epileptogenesis. The objective of this study was to characterize the phenotype of astrocytes and microglial cells in the hippocampus and temporal cortex of young male Wistar rats at 3 h, 1, 3, and 7 days after pentylenetetrazole-induced seizures. RT-qPCR was employed to examine the expression of glial genes (Gfap, Aif1, Slc1a1, Slc1a2, Slc1a3, Itpr2, Gdnf, Bdnf, Fgf2, Tgfb, Il1b, Tnf, Il1rn, Lcn2, S100a10, Nlrp3, Arg1). The most notable alterations in the expression of glial genes were observed on the first day following seizures in the temporal cortex. An increase in the expression of the Gfap, Slc1a2, Slc1a1, Il1b, Tnfa, Bdnf, and Fgf2 genes, and the A2 astrocyte condition marker S100a10, was observed. An increase in the expression of the Gfap and Slc1a2 genes was observed in the hippocampus on the first day after seizures. However, in contrast to the changes observed in the cortex, the changes in the hippocampus were opposite for the Il1rn, Bdnf, Tgfb, and Arg1 genes. Nevertheless, the alterations in GFAP and EAAT2 protein levels were not corroborated by Western blot analysis. Conversely, a more comprehensive immunohistochemical analysis confirmed an augmentation in the number of GFAP-positive cells in the hippocampus 1 day after seizures. Based on the presented evidence, we can conclude that a single convulsive seizure episode in 3-week-old rats results in transient astroglial activation and polarization to a neuroprotective phenotype (A2).


Assuntos
Astrócitos , Hipocampo , Microglia , Pentilenotetrazol , Ratos Wistar , Convulsões , Lobo Temporal , Animais , Masculino , Hipocampo/metabolismo , Hipocampo/patologia , Astrócitos/metabolismo , Astrócitos/patologia , Convulsões/induzido quimicamente , Convulsões/metabolismo , Convulsões/patologia , Ratos , Pentilenotetrazol/toxicidade , Microglia/metabolismo , Microglia/patologia , Lobo Temporal/metabolismo , Lobo Temporal/patologia , Fenótipo
12.
Acta Neuropathol ; 148(1): 37, 2024 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-39227502

RESUMO

The medial temporal lobe (MTL) is a hotspot for neuropathology, and measurements of MTL atrophy are often used as a biomarker for cognitive decline associated with neurodegenerative disease. Due to the aggregation of multiple proteinopathies in this region, the specific relationship of MTL atrophy to distinct neuropathologies is not well understood. Here, we develop two quantitative algorithms using deep learning to measure phosphorylated tau (p-tau) and TDP-43 (pTDP-43) pathology, which are both known to accumulate in the MTL and are associated with MTL neurodegeneration. We focus on these pathologies in the context of Alzheimer's disease (AD) and limbic predominant age-related TDP-43 encephalopathy (LATE) and apply our deep learning algorithms to distinct histology sections, on which MTL subregions were digitally annotated. We demonstrate that both quantitative pathology measures show high agreement with expert visual ratings of pathology and discriminate well between pathology stages. In 140 cases with antemortem MR imaging, we compare the association of semi-quantitative and quantitative postmortem measures of these pathologies in the hippocampus with in vivo structural measures of the MTL and its subregions. We find widespread associations of p-tau pathology with MTL subregional structural measures, whereas pTDP-43 pathology had more limited associations with the hippocampus and entorhinal cortex. Quantitative measurements of p-tau pathology resulted in a significantly better model of antemortem structural measures than semi-quantitative ratings and showed strong associations with cortical thickness and volume. By providing a more granular measure of pathology, the quantitative p-tau measures also showed a significant negative association with structure in a severe AD subgroup where semi-quantitative ratings displayed a ceiling effect. Our findings demonstrate the advantages of using quantitative neuropathology to understand the relationship of pathology to structure, particularly for p-tau, and motivate the use of quantitative pathology measurements in future studies.


Assuntos
Doença de Alzheimer , Lobo Temporal , Proteínas tau , Humanos , Doença de Alzheimer/patologia , Lobo Temporal/patologia , Lobo Temporal/diagnóstico por imagem , Masculino , Feminino , Idoso , Proteínas tau/metabolismo , Idoso de 80 Anos ou mais , Aprendizado Profundo , Proteínas de Ligação a DNA/metabolismo , Atrofia/patologia , Pessoa de Meia-Idade , Imageamento por Ressonância Magnética/métodos
13.
Mol Psychiatry ; 28(1): 168-190, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35931757

RESUMO

Duration of untreated psychosis (DUP) is defined as the time from the onset of psychotic symptoms until the first treatment. Studies have shown that longer DUP is associated with poorer response rates to antipsychotic medications and impaired cognition, yet the neurobiologic correlates of DUP are poorly understood. Moreover, it has been hypothesized that untreated psychosis may be neurotoxic. Here, we conducted a comprehensive review of studies that have examined the neurobiology of DUP. Specifically, we included studies that evaluated DUP using a range of neurobiologic and imaging techniques and identified 83 articles that met inclusion and exclusion criteria. Overall, 27 out of the total 83 studies (32.5%) reported a significant neurobiological correlate with DUP. These results provide evidence against the notion of psychosis as structurally or functionally neurotoxic on a global scale and suggest that specific regions of the brain, such as temporal regions, may be more vulnerable to the effects of DUP. It is also possible that current methodologies lack the resolution needed to more accurately examine the effects of DUP on the brain, such as effects on synaptic density. Newer methodologies, such as MR scanners with stronger magnets, PET imaging with newer ligands capable of measuring subcellular structures (e.g., the PET ligand [11C]UCB-J) may be better able to capture these limited neuropathologic processes. Lastly, to ensure robust and replicable results, future studies of DUP should be adequately powered and specifically designed to test for the effects of DUP on localized brain structure and function with careful attention paid to potential confounds and methodological issues.


Assuntos
Disfunção Cognitiva , Transtornos Psicóticos , Humanos , Encéfalo/patologia , Disfunção Cognitiva/patologia , Transtornos Psicóticos/diagnóstico , Transtornos Psicóticos/patologia , Lobo Temporal/patologia
14.
Epilepsia ; 65(4): 1092-1106, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38345348

RESUMO

OBJECTIVE: Epilepsy patients are often grouped together by clinical variables. Quantitative neuroimaging metrics can provide a data-driven alternative for grouping of patients. In this work, we leverage ultra-high-field 7-T structural magnetic resonance imaging (MRI) to characterize volumetric atrophy patterns across hippocampal subfields and thalamic nuclei in drug-resistant focal epilepsy. METHODS: Forty-two drug-resistant epilepsy patients and 13 controls with 7-T structural neuroimaging were included in this study. We measured hippocampal subfield and thalamic nuclei volumetry, and applied an unsupervised machine learning algorithm, Latent Dirichlet Allocation (LDA), to estimate atrophy patterns across the hippocampal subfields and thalamic nuclei of patients. We studied the association between predefined clinical groups and the estimated atrophy patterns. Additionally, we used hierarchical clustering on the LDA factors to group patients in a data-driven approach. RESULTS: In patients with mesial temporal sclerosis (MTS), we found a significant decrease in volume across all ipsilateral hippocampal subfields (false discovery rate-corrected p [pFDR] < .01) as well as in some ipsilateral (pFDR < .05) and contralateral (pFDR < .01) thalamic nuclei. In left temporal lobe epilepsy (L-TLE) we saw ipsilateral hippocampal and some bilateral thalamic atrophy (pFDR < .05), whereas in right temporal lobe epilepsy (R-TLE) extensive bilateral hippocampal and thalamic atrophy was observed (pFDR < .05). Atrophy factors demonstrated that our MTS cohort had two atrophy phenotypes: one that affected the ipsilateral hippocampus and one that affected the ipsilateral hippocampus and bilateral anterior thalamus. Atrophy factors demonstrated posterior thalamic atrophy in R-TLE, whereas an anterior thalamic atrophy pattern was more common in L-TLE. Finally, hierarchical clustering of atrophy patterns recapitulated clusters with homogeneous clinical properties. SIGNIFICANCE: Leveraging 7-T MRI, we demonstrate widespread hippocampal and thalamic atrophy in epilepsy. Through unsupervised machine learning, we demonstrate patterns of volumetric atrophy that vary depending on disease subtype. Incorporating these atrophy patterns into clinical practice could help better stratify patients to surgical treatments and specific device implantation strategies.


Assuntos
Epilepsia Resistente a Medicamentos , Epilepsia do Lobo Temporal , Humanos , Epilepsia do Lobo Temporal/diagnóstico por imagem , Epilepsia do Lobo Temporal/patologia , Imageamento por Ressonância Magnética/métodos , Hipocampo/diagnóstico por imagem , Hipocampo/patologia , Lobo Temporal/patologia , Atrofia/patologia , Epilepsia Resistente a Medicamentos/diagnóstico por imagem , Epilepsia Resistente a Medicamentos/patologia , Esclerose/patologia
15.
Eur J Neurol ; 31(2): e16124, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37933893

RESUMO

BACKGROUND: Predominant right temporal atrophy is a radiological sign usually associated with frontotemporal dementia but this sign can also be present in Alzheimer's disease. Given the overlap of clinical symptoms between the two conditions, it is important to know which characteristics allow them to be differentiated. OBJECTIVES: To compare clinical, neuropsychological and structural magnetic resonance imaging (MRI) data of subjects with prominent right anterior temporal atrophy, depending on the status of amyloid biomarkers. METHODS: Among patients followed in the dementia center of Ospedale Maggiore Policlinico, subjects with right anterior temporal atrophy, defined as grade 3 or 4 on the corresponding visual rating scale, were identified. Only subjects with both an MRI scan and amyloid status available were considered. For selected subjects, data were extracted from clinical and neuropsychological records at initial presentation and at last available follow-up. Two raters applied a protocol of eight visual rating scales to compare brain atrophy and white matter hyperintensities. RESULTS: Of 497 subjects, 17 fulfilled the inclusion criteria: 7 amyloid-positive and 10 amyloid-negative. At initial presentation, executive dysfunction and topographical disorientation were more common in amyloid-positive patients. At follow-up, behavioral symptoms, such as social awkwardness and compulsive attitude, were more frequent in the amyloid-negative patients. Amyloid-positive patients presented an overall worse neuropsychological performance, especially in the language and visuospatial domain, and had higher scores on the right anterior cingulate visual rating scale. CONCLUSION: Patients with predominant right temporal atrophy showed clinical, neuropsychological and radiological differences, depending on the status of amyloid biomarkers.


Assuntos
Doença de Alzheimer , Demência Frontotemporal , Humanos , Doença de Alzheimer/complicações , Imageamento por Ressonância Magnética , Testes Neuropsicológicos , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/patologia , Atrofia/patologia , Biomarcadores
16.
J Int Neuropsychol Soc ; 30(6): 584-593, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38389489

RESUMO

OBJECTIVE: We investigated how well a visual associative learning task discriminates Alzheimer's disease (AD) dementia from other types of dementia and how it relates to AD pathology. METHODS: 3,599 patients (63.9 ± 8.9 years old, 41% female) from the Amsterdam Dementia Cohort completed two sets of the Visual Association Test (VAT) in a single test session and underwent magnetic resonance imaging. We performed receiver operating curve analysis to investigate the VAT's discriminatory ability between AD dementia and other diagnoses and compared it to that of other episodic memory tests. We tested associations between VAT performance and medial temporal lobe atrophy (MTA), and amyloid status (n = 2,769, 77%). RESULTS: Patients with AD dementia performed worse on the VAT than all other patients. The VAT discriminated well between AD and other types of dementia (area under the curve range 0.70-0.86), better than other episodic memory tests. Six-hundred forty patients (17.8%) learned all associations on VAT-A, but not on VAT-B, and they were more likely to have higher MTA scores (odds ratios range 1.63 (MTA 0.5) through 5.13 for MTA ≥ 3, all p < .001) and to be amyloid positive (odds ratio = 3.38, 95%CI = [2.71, 4.22], p < .001) than patients who learned all associations on both sets. CONCLUSIONS: Performance on the VAT, especially on a second set administered immediately after the first, discriminates AD from other types of dementia and is associated with MTA and amyloid positivity. The VAT might be a useful, simple tool to assess early episodic memory deficits in the presence of AD pathology.


Assuntos
Doença de Alzheimer , Aprendizagem por Associação , Imageamento por Ressonância Magnética , Memória Episódica , Humanos , Feminino , Masculino , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/fisiopatologia , Doença de Alzheimer/complicações , Idoso , Pessoa de Meia-Idade , Aprendizagem por Associação/fisiologia , Demência/diagnóstico , Demência/fisiopatologia , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/patologia , Lobo Temporal/fisiopatologia , Transtornos da Memória/etiologia , Transtornos da Memória/diagnóstico , Transtornos da Memória/fisiopatologia , Diagnóstico Diferencial , Atrofia/patologia , Testes Neuropsicológicos/normas
17.
J Neuropsychiatry Clin Neurosci ; 36(4): 344-349, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38988189

RESUMO

OBJECTIVE: Socioemotional changes, rather than cognitive impairments, are the feature that defines behavioral variant frontotemporal dementia (bvFTD). Investigators have attributed the socioemotional changes in bvFTD and other dementias to frontal lobe dysfunction; however, recent work implies a further contribution from right anterior temporal disease. The authors evaluated relationships between regional brain atrophy and socioemotional changes in both bvFTD and early-onset Alzheimer's disease (EOAD). METHODS: This study explored the neuroanatomical correlations of performance on the Socioemotional Dysfunction Scale (SDS), an instrument previously shown to document socioemotional changes in bvFTD, among 13 patients with bvFTD not preselected for anterior temporal involvement and 16 age-matched patients with early-onset Alzheimer's disease (EOAD). SDS scores were correlated with volumes of regions of interest assessed with tensor-based morphometric analysis of MRI images. RESULTS: As expected, the bvFTD group had significantly higher SDS scores overall and smaller frontal regions compared with the EOAD group, which in turn had smaller volumes in temporoparietal regions. SDS scores significantly correlated with lateral anterior temporal lobe (ATL) atrophy, and a regression analysis that controlled for diagnosis indicated that SDS scores predicted lateral ATL volume. Within the bvFTD group, higher SDS scores were associated with smaller lateral and right ATL regions, as well as a smaller orbitofrontal cortex. Within the EOAD group, higher SDS scores were associated with a smaller right parietal cortex. CONCLUSIONS: This study confirms that, in addition to orbitofrontal disease, there is a prominent right and lateral ATL origin of socioemotional changes in bvFTD and further suggests that right parietal involvement contributes to socioemotional changes in EOAD.


Assuntos
Atrofia , Demência Frontotemporal , Imageamento por Ressonância Magnética , Lobo Temporal , Humanos , Demência Frontotemporal/patologia , Demência Frontotemporal/diagnóstico por imagem , Demência Frontotemporal/fisiopatologia , Masculino , Feminino , Lobo Temporal/patologia , Lobo Temporal/diagnóstico por imagem , Pessoa de Meia-Idade , Idoso , Atrofia/patologia , Testes Neuropsicológicos , Doença de Alzheimer/patologia , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/fisiopatologia , Doença de Alzheimer/complicações , Emoções/fisiologia
18.
Brain ; 146(3): 1021-1039, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35388420

RESUMO

Most individuals who experience aphasia after a stroke recover to some extent, with the majority of gains taking place in the first year. The nature and time course of this recovery process is only partially understood, especially its dependence on lesion location and extent, which are the most important determinants of outcome. The aim of this study was to provide a comprehensive description of patterns of recovery from aphasia in the first year after stroke. We recruited 334 patients with acute left hemisphere supratentorial ischaemic or haemorrhagic stroke and evaluated their speech and language function within 5 days using the Quick Aphasia Battery (QAB). At this initial time point, 218 patients presented with aphasia. Individuals with aphasia were followed longitudinally, with follow-up evaluations of speech and language at 1 month, 3 months, and 1 year post-stroke, wherever possible. Lesions were manually delineated based on acute clinical MRI or CT imaging. Patients with and without aphasia were divided into 13 groups of individuals with similar, commonly occurring patterns of brain damage. Trajectories of recovery were then investigated as a function of group (i.e. lesion location and extent) and speech/language domain (overall language function, word comprehension, sentence comprehension, word finding, grammatical construction, phonological encoding, speech motor programming, speech motor execution, and reading). We found that aphasia is dynamic, multidimensional, and gradated, with little explanatory role for aphasia subtypes or binary concepts such as fluency. Patients with circumscribed frontal lesions recovered well, consistent with some previous observations. More surprisingly, most patients with larger frontal lesions extending into the parietal or temporal lobes also recovered well, as did patients with relatively circumscribed temporal, temporoparietal, or parietal lesions. Persistent moderate or severe deficits were common only in patients with extensive damage throughout the middle cerebral artery distribution or extensive temporoparietal damage. There were striking differences between speech/language domains in their rates of recovery and relationships to overall language function, suggesting that specific domains differ in the extent to which they are redundantly represented throughout the language network, as opposed to depending on specialized cortical substrates. Our findings have an immediate clinical application in that they will enable clinicians to estimate the likely course of recovery for individual patients, as well as the uncertainty of these predictions, based on acutely observable neurological factors.


Assuntos
Afasia , Acidente Vascular Cerebral , Humanos , Afasia/patologia , Lobo Temporal/patologia , Fala , Idioma , Imageamento por Ressonância Magnética
19.
Brain ; 146(2): 549-560, 2023 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-35978480

RESUMO

Drug-resistant mesial-temporal lobe epilepsy is a devastating disease with seizure onset in the hippocampal formation. A fraction of hippocampi samples from epilepsy-surgical procedures reveals a peculiar histological pattern referred to as 'gliosis only' with unresolved pathogenesis and enigmatic sequelae. Here, we hypothesize that 'gliosis only' represents a particular syndrome defined by distinct clinical and molecular characteristics. We curated an in-depth multiparameter integration of systematic clinical, neuropsychological as well as neuropathological analysis from a consecutive cohort of 627 patients, who underwent hippocampectomy for drug-resistant temporal lobe epilepsy. All patients underwent either classic anterior temporal lobectomy or selective amygdalohippocampectomy. On the basis of their neuropathological exam, patients with hippocampus sclerosis and 'gliosis only' were characterized and compared within the whole cohort and within a subset of matched pairs. Integrated transcriptional analysis was performed to address molecular differences between both groups. 'Gliosis only' revealed demographics, clinical and neuropsychological outcome fundamentally different from hippocampus sclerosis. 'Gliosis only' patients had a significantly later seizure onset (16.3 versus 12.2 years, P = 0.005) and worse neuropsychological outcome after surgery compared to patients with hippocampus sclerosis. Epilepsy was less amendable by surgery in 'gliosis only' patients, resulting in a significantly worse rate of seizure freedom after surgery in this subgroup (43% versus 68%, P = 0.0001, odds ratio = 2.8, confidence interval 1.7-4.7). This finding remained significant after multivariate and matched-pairs analysis. The 'gliosis only' group demonstrated pronounced astrogliosis and lack of significant neuronal degeneration in contrast to characteristic segmental neuron loss and fibrillary astrogliosis in hippocampus sclerosis. RNA-sequencing of gliosis only patients deciphered a distinct transcriptional programme that resembles an innate inflammatory response of reactive astrocytes. Our data indicate a new temporal lobe epilepsy syndrome for which we suggest the term 'Innate inflammatory gliosis only'. 'Innate inflammatory gliosis only' is characterized by a diffuse gliosis pattern lacking restricted hippocampal focality and is poorly controllable by surgery. Thus, 'innate inflammatory gliosis only' patients need to be clearly identified by presurgical examination paradigms of pharmacoresistant temporal lobe epilepsy patients; surgical treatment of this subgroup should be considered with great precaution. 'Innate inflammatory gliosis only' requires innovative pharmacotreatment strategies.


Assuntos
Epilepsia Resistente a Medicamentos , Epilepsia do Lobo Temporal , Esclerose Hipocampal , Humanos , Epilepsia do Lobo Temporal/patologia , Gliose/patologia , Esclerose/patologia , Hipocampo/patologia , Lobo Temporal/patologia , Epilepsia Resistente a Medicamentos/complicações , Resultado do Tratamento
20.
Brain ; 146(1): 20-41, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36331542

RESUMO

Following prolonged neglect during the formative decades of behavioural neurology, the temporopolar region has become a site of vibrant research on the neurobiology of cognition and conduct. This turnaround can be attributed to increasing recognition of neurodegenerative diseases that target temporopolar regions for peak destruction. The resultant syndromes include behavioural dementia, associative agnosia, semantic forms of primary progressive aphasia and semantic dementia. Clinicopathological correlations show that object naming and word comprehension are critically dependent on the language-dominant (usually left) temporopolar region, whereas behavioural control and non-verbal object recognition display a more bilateral representation with a rightward bias. Neuroanatomical experiments in macaques and neuroimaging in humans show that the temporoparietal region sits at the confluence of auditory, visual and limbic streams of processing at the downstream (deep) pole of the 'what' pathway. The functional neuroanatomy of this region revolves around three axes, an anterograde horizontal axis from unimodal to heteromodal and paralimbic cortex; a radial axis where visual (ventral), auditory (dorsal) and paralimbic (medial) territories encircle temporopolar cortex and display hemispheric asymmetry; and a vertical depth-of-processing axis for the associative elaboration of words, objects and interoceptive states. One function of this neural matrix is to support the transformation of object and word representations from unimodal percepts to multimodal concepts. The underlying process is likely to start at canonical gateways that successively lead to generic (superordinate), specific (basic) and unique levels of recognition. A first sign of left temporopolar dysfunction takes the form of taxonomic blurring where boundaries among categories are preserved but not boundaries among exemplars of a category. Semantic paraphasias and coordinate errors in word-picture verification tests are consequences of this phenomenon. Eventually, boundaries among categories are also blurred and comprehension impairments become more profound. The medial temporopolar region belongs to the amygdalocentric component of the limbic system and stands to integrate exteroceptive information with interoceptive states underlying social interactions. Review of the pertinent literature shows that word comprehension and conduct impairments caused by temporopolar strokes and temporal lobectomy are far less severe than those seen in temporopolar atrophies. One explanation for this unexpected discrepancy invokes the miswiring of residual temporopolar neurons during the many years of indolently progressive neurodegeneration. According to this hypothesis, the temporopolar regions become not only dysfunctional but also sources of aberrant outputs that interfere with the function of areas elsewhere in the language and paralimbic networks, a juxtaposition not seen in lobectomy or stroke.


Assuntos
Acidente Vascular Cerebral , Lobo Temporal , Humanos , Lobo Temporal/patologia , Encéfalo/diagnóstico por imagem , Córtex Cerebral/patologia , Idioma , Semântica , Testes Neuropsicológicos , Imageamento por Ressonância Magnética/métodos
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