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1.
J Alzheimers Dis ; 97(4): 1777-1792, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38339927

RESUMO

Background: Executive functions (EF) are central to instrumental activities of daily living (IADL). A novel approach to the assessment of the impact of EF difficulties on IADL may be through the speech acts produced when performing IADL-inspired tasks in a laboratory-apartment. Speech acts may act as a window to the difficulties encountered during task performance. Objective: We aim to 1) qualitatively describe the speech acts produced by participants with mild neurocognitive disorder (mild NCD) and healthy controls (HC) as they performed 4 IADL-inspired tasks in a laboratory-apartment, and to then 2) compare their use in both groups. Methods: The participants' performance was videotaped, and speech acts produced were transcribed. Qualitative description of all speech acts was performed, followed by a deductive-inductive pattern coding of data. Statistical analyses were performed to further compare their use by mild NCD participants and HC. Results: Twenty-two participants took part in the study (n mild NCD = 11; n HC = 11). Meta-categories of data emerged from pattern coding: strategies, barriers, reactions, and consequences. Mild NCD participants used significantly more strategies and barriers than did HC. They were more defensive of their performance, and more reactive to their difficulties than HC. Mild NCD participants' verification of having completed all tasks was less efficient than controls. Conclusions: An assessment of speech acts produced during the performance of IADL-inspired tasks in a laboratory-apartment may allow to detect changes in the use of language which may reflect EF difficulties linked to cognitive decline.


Assuntos
Disfunção Cognitiva , Envelhecimento Saudável , Humanos , Atividades Cotidianas/psicologia , Fala , Disfunção Cognitiva/psicologia , Função Executiva , Testes Neuropsicológicos
2.
Am J Speech Lang Pathol ; 32(6): 2871-2888, 2023 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-37758196

RESUMO

PURPOSE: Main concept (MC) analysis is a well-documented method of discourse analysis in adults with and without brain injury. This study aims to develop a MC checklist that is culturally and linguistically adapted for Canadian French speakers and examine its reliability. We also documented microstructural properties and provide a normative reference in persons not brain injured (PNBIs). METHOD: Discourse samples from 43 PNBIs were collected. All participants completed the Cinderella story retell task twice. Manual transcription was performed for all samples. The 34 MCs for the Cinderella story retell task were adapted into Canadian French and used to score all transcripts. In addition, microstructural variables were extracted using Computerized Language Analysis (CLAN). Intraclass correlation coefficients were computed to assess interrater reliability for MC codes and microstructural variables. Test-retest reliability was assessed using intraclass correlations, Spearman's rho correlations, and the Wilcoxon signed-ranks test. Bland-Altman plots were used to examine the agreement of the discourse measures between the two sessions. RESULTS: The MC checklist for the Cinderella story retell task adapted for Canadian French speakers is provided. Good-to-excellent interrater reliability was obtained for most MC codes; however, reliability ranged from poor to excellent for the "inaccurate and incomplete" code. Microstructural variables demonstrated excellent interrater reliability. Test-retest reliability ranged from poor to excellent for all variables, with the majority falling between moderate and excellent. Bland-Altman plots illustrated the limits of agreement between test and retest. CONCLUSIONS: This study provides the MC checklist for clinicians and researchers working with Canadian French speakers when assessing discourse with the Cinderella story retell task. It also addresses the gap in available psychometric data regarding test-retest reliability in PNBIs. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.24171087.


Assuntos
Lesões Encefálicas , Idioma , Adulto , Humanos , Reprodutibilidade dos Testes , Canadá , Psicometria
3.
Brain Lang ; 244: 105300, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37633250

RESUMO

We systematically reviewed the literature on neural changes following anomia treatment post-stroke. We conducted electronic searches of CINAHL, Cochrane Trials, Embase, Ovid MEDLINE, MEDLINE-in-Process and PsycINFO databases; two independent raters assessed all abstracts and full texts. Accepted studies reported original data on adults with post-stroke aphasia, who received behavioural treatment for anomia, and magnetic resonance brain imaging (MRI) pre- and post-treatment. Search results yielded 2481 citations; 33 studies were accepted. Most studies employed functional MRI and the quality of reporting neuroimaging methodology was variable, particularly for pre-processing steps and statistical analyses. The most methodologically robust data were synthesized, focusing on pre- versus post-treatment contrasts. Studies more commonly reported increases (versus decreases) in activation following naming therapy, primarily in the left supramarginal gyrus, and left/bilateral precunei. Our findings highlight the methodological heterogeneity across MRI studies, and the paucity of robust evidence demonstrating direct links between brain and behaviour in anomia rehabilitation.


Assuntos
Afasia , Acidente Vascular Cerebral , Adulto , Humanos , Anomia/diagnóstico por imagem , Anomia/etiologia , Anomia/terapia , Afasia/diagnóstico por imagem , Afasia/etiologia , Afasia/terapia , Neuroimagem , Plasticidade Neuronal , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/terapia
4.
Int J Lang Commun Disord ; 58(4): 1061-1081, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36705070

RESUMO

BACKGROUND: Discourse analysis has recently received much attention in the aphasia literature. Even if post-stroke language recovery occurs throughout the longitudinal continuum of recovery, very few studies have documented discourse changes from the hyperacute to the chronic phases of recovery. AIMS: To document a multilevel analysis of discourse changes from the hyperacute phase to the chronic phase of post-stroke recovery using a series of single cases study designs. METHODS & PROCEDURES: Four people with mild to moderate post-stroke aphasia underwent four assessments (hyperacute: 0-24 h; acute: 24-72 h; subacute: 7-14 days; and chronic: 6-12 months post-onset). Three discourse tasks were performed at each time point: a picture description, a personal narrative and a story retelling. Multilevel changes in terms of macro- and microstructural aspects were analysed. The results of each discourse task were combined for each time point. Individual effect sizes were computed to evaluate the relative strength of changes in an early and a late recovery time frame. OUTCOMES & RESULTS: Macrostructural results revealed improvements throughout the recovery continuum in terms of coherence and thematic efficiency. Also, the microstructural results demonstrated linguistic output improvement for three out of four participants. Namely, lexical diversity and the number of correct information units/min showed a greater gain in the early compared with the late recovery phase. CONCLUSIONS & IMPLICATIONS: This study highlights the importance of investigating all discourse processing levels as the longitudinal changes in discourse operate differently at each phase of recovery. Overall results support future longitudinal discourse investigation in people with post-stroke aphasia. WHAT THIS PAPER ADDS: What is already known on the subject Multi-level discourse analysis allows for in-depth analysis of underlying discourse processes. To date, very little is known on the longitudinal discourse changes from aphasia onset through to the chronic stage of recovery. This study documents multi-level discourse features in four people with mild to moderate aphasia in the hyperacute, acute, subacute and chronic stage of post-stroke aphasia recovery. What this paper adds to existing knowledge The study found that most discourse variables demonstrated improvement throughout time. Macrostructural variables of coherence and thematic units improved throughout the continuum whereas microstructural variables demonstrated greater gains in the early compared to the late period of recovery. What are the potential or actual clinical implications of this work? This study suggests that multilevel discourse analysis will allow a better understanding of post-stroke aphasia recovery, although more research is needed to determine the clinical utility of these findings. Future research may wish to investigate longitudinal discourse recovery in a larger sample of people with aphasia with heterogenous aphasia profiles and severities.


Assuntos
Afasia , Acidente Vascular Cerebral , Humanos , Afasia/etiologia , Afasia/reabilitação , Atenção , Idioma , Linguística , Acidente Vascular Cerebral/complicações , Estudos Longitudinais , Análise Multinível , Recuperação de Função Fisiológica
5.
Am J Speech Lang Pathol ; 31(6): 2825-2834, 2022 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-36332144

RESUMO

PURPOSE: During the COVID-19 pandemic, clinicians and researchers have increasingly used remote online assessments to pursue their activities, but mostly with tests not validated for videoconference administration. This study aims to validate the remote online administration of picture description in Canadian French neurotypical speakers and to explore the thematic unit (TU) checklist recently developed. METHOD: Spoken discourse elicited through the picture description task of the Western Aphasia Battery-Revised (WAB-R) was collected from Canadian French neurotypical speakers from Québec aged between 50 and 79 years old. Forty-seven participants completed the task in person, and 49 participants completed the task by videoconference. Videos of each discourse sample were transcribed using CHAT conventions. Microstructural variables were extracted using the CLAN (Computerized Language ANalysis) program, whereas thematic informativeness was scored for each sample using TUs. Chi-square tests were conducted to compare both groups on each TU; t tests were also performed on the total score of TUs and microstructural variables. RESULTS: Groups were matched on sex, age, and education variables. The t tests revealed no intergroup difference for the total TU score and for the microstructural variables (e.g., mean length of utterances and number of words per minute). Chi-square tests showed no significant intergroup difference for all 16 TUs. CONCLUSIONS: These findings support remote online assessment of the picnic scene of the WAB-R picture description in Canadian French neurotypical speakers. These results also validate the 16 TUs most consistently produced. The use of videoconference could promote and improve the recruitment of participants who are usually less accessible, such as people using assistive mobility technologies. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.21476961.


Assuntos
Afasia , COVID-19 , Humanos , Pessoa de Meia-Idade , Idoso , Idioma , Pandemias , Canadá , Comunicação por Videoconferência
6.
J Neurol Sci ; 441: 120377, 2022 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-36049374

RESUMO

Diffusion imaging (DWI) is considered an optimal technique to detect hyperacute cerebral ischemia and has thus enriched the clinical management of patients with suspected stroke. Researchers have taken this technique beyond with Diffusion Tensor Imaging (DTI)-extracted measures, which have been proposed as biomarkers of stroke progression. A large body of literature report on the correlates between pathophysiological events, such as cytotoxic and vasogenic edema, and diffusion changes in the brain. However, a unified picture of these changes, and their exploration as stroke pathology progression biomarkers, remains to be done. We present here a narrative review on the different pathophysiological events underlying stroke from onset until late subacute stages and its relation to different brain edema forms. Studies included in this review used either DWI and/or DTI analysis in hyperacute (<24 h), acute (1-7 days), early subacute (7-30 days) and/or late subacute (1-6 months) phase of stroke, including human and animal models. Our conclusions are that diffusion measures should be considered as a potential proxy measure for stroke neuroinflammation status, specially in early stages of the disease. Furthermore, we suggest that the choice of diffusion measures and the interpretation of their changes, in both research and clinical settings, need to be linked to the different stroke phases to account correctly for the progression, and eventual resolution, of neuroinflammation.


Assuntos
Isquemia Encefálica , Acidente Vascular Cerebral , Animais , Isquemia Encefálica/complicações , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/patologia , Infarto Cerebral/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Imagem de Tensor de Difusão/métodos , Humanos , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/patologia
7.
J Psycholinguist Res ; 51(1): 93-133, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35091906

RESUMO

Research on language processing requires language-specific norms of pictorial and linguistic experimental stimuli across different psycholinguistic variables. Such normative data have not yet been collected for Lebanese Arabic (LA), an Arabic dialect. Arabic languages are characterized by diglossia: while modern standard Arabic is their common means of formal communication, Arabic dialects are the medium of oral communication within each community. This claims for specific dialectal norms. Thus, the main goal of the present study was to collect normative LA data for 380 pictures taken from Cykowicz, Friedman, Rothstein, and Snodgrass (The Quarterly Journal of Experimental Psychology Section A 50(3):560-585; including the 260 pictures of Snodgrass & Vanderwart in Journal of experimental psychology: Human learning and memory 6(2):174-215, 1980) using a sample of 248 native LA speakers. Norms are reported for name agreement, conceptual familiarity, imageability and subjective frequency, together with word length in number of letters and syllables. We compared the obtained norms with the normative data of other Arabic dialects (Levantine, Tunisian and Gulf Arabic) and with English, French and Spanish. Results showed the distinction of LA from the other Arabic dialects. This provides support of specific dialectal Arabic norms and will allow researchers to rigorously select the stimuli to investigate language processing in LA-speaking populations.


Assuntos
Idioma , Nomes , Humanos , Psicolinguística , Reconhecimento Psicológico , Percepção Visual
8.
J Parkinsons Dis ; 12(1): 229-241, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34690149

RESUMO

BACKGROUND: Rapid-eye-movement sleep behavior disorder (RBD) is a major risk factor for Parkinson's disease and dementia with Lewy bodies. More than a third of RBD patients have mild cognitive impairment (MCI), but their specific structural brain alterations remain poorly understood. OBJECTIVE: This study aimed to investigate the local deformation and volume of gray and white matter tissue underlying MCI in RBD. METHODS: Fifty-two idiopathic RBD patients, including 17 with MCI (33%), underwent polysomnography, neuropsychological, neurological, and magnetic resonance imaging assessments. MCI diagnosis was based on a subjective complaint, cognitive impairment on the neuropsychological battery, and preserved daily functioning. Forty-one controls were also included. Deformation-based morphometry (DBM), voxel-based morphometry (VBM), and regional volume analyses of the corpus callosum and cholinergic basal forebrain were performed. Multiple regression models were also computed using anatomical, cognitive (composite z scores), and motor parameters. RESULTS: Globally, patients with MCI displayed a widespread pattern of local deformation and volume atrophy in the cortical (bilateral insula, cingulate cortex, precuneus, frontal, temporal and occipital regions, right angular gyrus, and mid-posterior segment of the corpus callosum) and subcortical (brainstem, corona radiata, basal ganglia, thalamus, amygdala, and right hippocampus) regions compared to patients without MCI (DBM) or controls (DBM and VBM). Moreover, brain deformation (DBM) in patients were associated with lower performance in attention and executive functions, visuospatial abilities, and higher motor symptoms severity. CONCLUSION: The present study identified novel brain structural alterations in RBD patients with MCI which correlated with poorer cognitive performance. These results are consistent with those reported in patients with synucleinopathies-related cognitive impairment.


Assuntos
Disfunção Cognitiva , Doença de Parkinson , Transtorno do Comportamento do Sono REM , Atrofia/patologia , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Disfunção Cognitiva/complicações , Disfunção Cognitiva/etiologia , Humanos , Imageamento por Ressonância Magnética , Doença de Parkinson/complicações , Transtorno do Comportamento do Sono REM/complicações , Transtorno do Comportamento do Sono REM/diagnóstico por imagem , Transtorno do Comportamento do Sono REM/patologia
9.
Am J Speech Lang Pathol ; 31(1): 257-270, 2022 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-34735273

RESUMO

PURPOSE: The main aim of this study is to provide French Canadian reference data for quantitative measures extracted from connected speech samples elicited by the Western Aphasia Battery-Revised picnic scene, a discourse task frequently used in clinical assessment of acquired language disorders. METHOD: Our sample consisted of 62 healthy French Canadian adults divided in two age groups: a 50- to 69-year-old group and a 70- to 90-year-old group. RESULTS: High interrater reliability scores were obtained for most of the variables. Most connected speech variables did not demonstrate an age effect. However, the 70- to 90-year-old group produced more repetitions than the 50- to 69-year-old group and displayed reduced communication efficiency (number of information content units per minute). CONCLUSION: These findings contribute to building a reference data set to analyze descriptive discourse production in clinical settings.


Assuntos
Afasia , Adulto , Idoso , Idoso de 80 Anos ou mais , Afasia/diagnóstico , Canadá , Humanos , Idioma , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Fala
10.
J Neurosci Methods ; 367: 109435, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34915047

RESUMO

Combining MRI modalities is a growing trend in neurosciences. It provides opportunities to investigate the brain architecture supporting cognitive functions. Integrating fMRI activation to guide dMRI tractography offers potential advantages over standard tractography methods. A quick glimpse of the literature on this topic reveals that this technique is challenging, and no consensus or "best practices" currently exist, at least not within a single document. We present the first attempt to systematically analyze and summarize the literature of 80 studies that integrated task-based fMRI results to guide tractography, over the last two decades. We report 19 findings that cover challenges related to sample size, microstructure modelling, seeding methods, multimodal space registration, false negatives/positives, specificity/validity, gray/white matter interface and more. These findings will help the scientific community (1) understand the strengths and limitations of the approaches, (2) design studies using this integrative framework, and (3) motivate researchers to fill the gaps identified. We provide references toward best practices, in order to improve the overall result's replicability, sensitivity, specificity, and validity.


Assuntos
Imageamento por Ressonância Magnética , Substância Branca , Encéfalo/diagnóstico por imagem , Imagem de Tensor de Difusão/métodos , Substância Cinzenta , Substância Branca/diagnóstico por imagem
11.
Front Neurol ; 11: 120, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32153496

RESUMO

Background: The greatest degree of language recovery in post-stroke aphasia takes place within the first weeks. Aphasia severity and lesion measures have been shown to be good predictors of long-term outcomes. However, little is known about their implications in early spontaneous recovery. The present study sought to determine which factors better predict early language outcomes in individuals with post-stroke aphasia. Methods: Twenty individuals with post-stroke aphasia were assessed <72 h (acute) and 10-14 days (subacute) after stroke onset. We developed a composite score (CS) consisting of several linguistic sub-tests: repetition, oral comprehension and naming. Lesion volume, lesion load and diffusion measures [fractional anisotropy (FA) and axial diffusivity (AD)] from both arcuate fasciculi (AF) were also extracted using MRI scans performed at the same time points. A series of regression analyses were performed to predict the CS at the second assessment. Results: Among the diffusion measures, only FA from right AF was found to be a significant predictor of early subacute aphasia outcome. However, when combined in two hierarchical models with FA, age and either lesion load or lesion size, the initial aphasia severity was found to account for most of the variance (R 2 = 0.678), similarly to the complete models (R 2 = 0.703 and R 2 = 0.73, respectively). Conclusions: Initial aphasia severity was the best predictor of early post-stroke aphasia outcome, whereas lesion measures, though highly correlated, show less influence on the prediction model. We suggest that factors predicting early recovery may differ from those involved in long-term recovery.

13.
Neurocase ; 25(3-4): 118-129, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31256711

RESUMO

Despite a well-documented pattern of semantic impairment, the patterns of brain activation during semantic processing in semantic variant primary progressive aphasia (svPPA) still remain poorly understood. In the current study, one svPPA patient (EC) and six elderly controls carried out a general-level semantic categorization task while their brain activity was recorded using magnetoencephalography (MEG). Despite similar behavioral performance, EC showed hyperactivation of the left inferior temporal gyrus (ITG) and right anterior temporal lobe (ATL) relative to controls. This suggests that periatrophic regions within the ATL region may support preserved semantic abilities in svPPA.


Assuntos
Afasia Primária Progressiva/fisiopatologia , Encéfalo/fisiopatologia , Idoso , Feminino , Humanos , Magnetoencefalografia , Masculino , Testes Neuropsicológicos , Lobo Temporal/fisiopatologia
14.
Behav Res Methods ; 51(5): 2094-2105, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31016685

RESUMO

Perceptual experience plays a critical role in the conceptual representation of words. Higher levels of semantic variables such as imageability, concreteness, and sensory experience are generally associated with faster and more accurate word processing. Nevertheless, these variables tend to be assessed mostly on the basis of visual experience. This underestimates the potential contributions of other perceptual modalities. Accordingly, recent evidence has stressed the importance of providing modality-specific perceptual strength norms. In the present study, we developed French Canadian norms of visual and auditory perceptual strength (i.e., the modalities that have major impact on word processing) for 3,596 nouns. We then explored the relationship between these newly developed variables and other lexical, orthographic, and semantic variables. Finally, we demonstrated the contributions of visual and auditory perceptual strength ratings to visual word processing beyond those of other semantic variables related to perceptual experience (e.g., concreteness, imageability, and sensory experience ratings). The ratings developed in this study are a meaningful contribution toward the implementation of new studies that will shed further light on the interaction between linguistic, semantic, and perceptual systems.


Assuntos
Psicolinguística , Adolescente , Insuficiência Adrenal , Adulto , Canadá , Cognição , Feminino , Retardo do Crescimento Fetal , Humanos , Masculino , Osteocondrodisplasias , Semântica , Anormalidades Urogenitais , Adulto Jovem
15.
Behav Res Methods ; 51(5): 2238-2247, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30128888

RESUMO

In the last decade, research has shown that word processing is influenced by the lexical and semantic features of words. However, norms for a crucial semantic variable-that is, conceptual familiarity-have not been available for a sizeable French database. We thus developed French Canadian conceptual familiarity norms for 3,596 nouns. This enriches Desrochers and Thompson's (2009) database, in which subjective frequency and imageability values are already available for the same words. We collected online data from 313 Canadian French speakers. The full database of conceptual familiarity ratings is freely available at http://lingualab.ca/fr/projets/normes-de-familiarite-conceptuelle . We then demonstrated the utility of these new conceptual familiarity norms by assessing their contribution to lexical decision times. We conducted a stepwise regression model with conceptual familiarity in the last step. This allowed us to assess the independent contribution of conceptual familiarity beyond the contributions of other well-known psycholinguistic variables, such as frequency, imageability, and age of acquisition. The results showed that conceptual familiarity facilitated lexical decision latencies. In sum, these ratings will help researchers select French stimuli for experiments in which conceptual familiarity must be taken into account.


Assuntos
Reconhecimento Psicológico , Adolescente , Adulto , Canadá , Bases de Dados Factuais , Tomada de Decisões , Feminino , Humanos , Masculino , Psicolinguística , Semântica , Adulto Jovem
16.
J Alzheimers Dis ; 65(2): 519-542, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30103314

RESUMO

The language changes that occur over the course of Alzheimer's disease (AD) can impact communication abilities and have profound functional consequences. Picture description tasks can be used to approximate everyday communication abilities of AD patients. As various methods and variables have been studied over the years, current knowledge about the most affected features of AD discourse in the context of picture descriptions is difficult to summarize. This systematic review aims to provide researchers with an overview of the most common areas of impairment in AD discourse as they appear in picture description tasks. Based on the 44 articles fulfilling inclusion criteria, our findings reflect a multidimensional pattern of changes in the production (speech rate), syntactic (length of utterance), lexical (word-frequency and use of pronouns), fluency (repetitions and word-finding difficulties), semantic (information units), and discourse (efficiency) domains. We discuss our findings in the light of current research and point to potential scientific and clinical uses of picture description tasks in the context of AD.


Assuntos
Doença de Alzheimer/diagnóstico , Transtornos da Linguagem/diagnóstico , Fala , Doença de Alzheimer/psicologia , Humanos , Transtornos da Linguagem/etiologia , Testes Neuropsicológicos
17.
Neuropsychology ; 32(4): 417-435, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29809032

RESUMO

OBJECTIVE: Semantic memory impairment has been documented in individuals with amnestic Mild cognitive impairment (aMCI), who are at risk of developing Alzheimer's disease (AD), yet little is known about the neural basis of this breakdown. The aim of this study was to investigate the brain mechanisms associated with semantic performance in aMCI patients. METHOD: A group of aMCI patients and a group of healthy controls carried out a semantic categorization task while their brain activity was recorded using magnetoencephalography (MEG). During the task, participants were shown famous faces and had to determine whether each famous person matched a given occupation. The main hypotheses were that (a) semantic processing should be compromised for aMCI patients, and (b) these deficits should be associated with cortical dysfunctions within specific areas of the semantic network. RESULTS: Behavioral results showed that aMCI participants were significantly slower and less accurate than controls at the semantic task. Additionally, relative to controls, a significant pattern of hyperactivation was found in the aMCI group within specific regions of the extended semantic network, including the right anterior temporal lobe (ATL) and fusiform gyrus. CONCLUSIONS: Abnormal functional activation within key areas of the semantic network suggests that it is compromised early in the disease process. Moreover, this pattern of right ATL and fusiform gyrus hyperactivation was positively associated with gray matter integrity in specific areas, but was not associated with any pattern of atrophy, suggesting that this pattern of hyperactivation may precede structural alteration of the semantic network in aMCI. (PsycINFO Database Record


Assuntos
Amnésia/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Disfunção Cognitiva/diagnóstico por imagem , Rede Nervosa/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Amnésia/fisiopatologia , Encéfalo/fisiopatologia , Mapeamento Encefálico , Disfunção Cognitiva/fisiopatologia , Feminino , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/fisiopatologia , Humanos , Magnetoencefalografia , Masculino , Memória/fisiologia , Rede Nervosa/fisiopatologia , Testes Neuropsicológicos
18.
Cereb Cortex ; 26(6): 2650-62, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-25994962

RESUMO

Clinical symptoms observed in Alzheimer's disease (AD) patients may reflect variations within specific large-scale brain networks, modeling AD as a disconnection syndrome. The present magnetic resonance imaging study aims to compare the organization of gray matter structural covariance networks between 109 cognitively unimpaired controls (CTRL) and 109 AD patients positive to beta-amyloid at the early stages of the disease, using voxel-based morphometry. The default-mode network (DMN; medial temporal lobe subsystem) was less extended in AD patients in comparison with CTRL, with a significant decrease in the structural association between the entorhinal cortex and the medial prefrontal and the dorsolateral prefrontal cortices. The DMN (midline core subsystem) was also less extended in AD patients. Trends toward increased structural association were observed in the salience and executive control networks. The observed changes suggest that early disruptions in structural association between heteromodal association cortices and the entorhinal cortex could contribute to an isolation of the hippocampal formation, potentially giving rise to the clinical hallmark of AD, progressive memory impairment. It also provides critical support to the hypothesis that the reduced connectivity within the DMN in early AD is accompanied by an enhancement of connectivity in the salience and executive control networks.


Assuntos
Doença de Alzheimer/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Substância Cinzenta/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/líquido cefalorraquidiano , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Biomarcadores/líquido cefalorraquidiano , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Entrevista Psiquiátrica Padronizada , Pessoa de Meia-Idade , Vias Neurais/diagnóstico por imagem , Fragmentos de Peptídeos/líquido cefalorraquidiano
19.
Neuroimage Clin ; 8: 345-55, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26106560

RESUMO

The present study investigated the pattern of longitudinal changes in cognition and anatomy in three variants of primary progressive aphasia (PPA). Eight patients with the non-fluent variant of PPA (nfvPPA), 13 patients with the semantic variant (svPPA), seven patients with the logopenic variant (lvPPA), and 29 age-matched, neurologically healthy controls were included in the study. All participants underwent longitudinal MRI, neuropsychological and language testing at baseline and at a 1-year follow-up. Tenser-based morphometry (TBM) was applied to T1-weighted MRI images in order to map the progression of gray and white matter atrophy over a 1-year period. Results showed that each patient group was characterized by a specific pattern of cognitive and anatomical changes. Specifically, nfvPPA patients showed gray matter atrophy progression in the left frontal and subcortical areas as well as a decline in motor speech and executive functions; svPPA patients presented atrophy progression in the medial and lateral temporal lobe and decline in semantic memory abilities; and lvPPA patients showed atrophy progression in lateral/posterior temporal and medial parietal regions with a decline in memory, sentence repetition and calculations. In addition, in all three variants, the white matter fibers underlying the abovementioned cortical areas underwent significant volume contraction over a 1-year period. Overall, these results indicate that the three PPA variants present distinct patterns of neuroanatomical contraction, which reflect their clinical and cognitive progression.


Assuntos
Afasia Primária Progressiva/patologia , Progressão da Doença , Função Executiva/fisiologia , Substância Cinzenta/patologia , Imageamento por Ressonância Magnética/métodos , Idoso , Afasia Primária Progressiva/fisiopatologia , Atrofia/patologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Afasia Primária Progressiva não Fluente/patologia , Afasia Primária Progressiva não Fluente/fisiopatologia
20.
Neurocase ; 21(5): 563-72, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25274199

RESUMO

We aimed to characterize difficulties in famous face naming in three poststroke aphasic patients with a lesion limited to the left mid-posterior temporal language regions, sparing the anterior temporal lobe. The patients did not present semantic deficits specific to known people. Nonetheless, they showed difficulties naming famous buildings in addition to famous faces, but they were comparable to healthy controls in generating proper names. Our results support the critical role of the mid-posterior temporal language regions in the lexical retrieval of proper names, namely from pictorial stimuli, in absence of semantic impairments.


Assuntos
Anomia/patologia , Afasia/patologia , Rememoração Mental/fisiologia , Acidente Vascular Cerebral/complicações , Lobo Temporal/patologia , Idoso , Anomia/complicações , Afasia/complicações , Pessoas Famosas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nomes , Semântica
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