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1.
medRxiv ; 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38645132

RESUMO

Cell-free DNA (cfDNA) is increasingly recognized as a promising biomarker candidate for disease monitoring. However, its utility in neurodegenerative diseases, like amyotrophic lateral sclerosis (ALS), remains underexplored. Existing biomarker discovery approaches are tailored to a specific disease context or are too expensive to be clinically practical. Here, we address these challenges through a new approach combining advances in molecular and computational technologies. First, we develop statistical tools to select tissue-informative DNA methylation sites relevant to a disease process of interest. We then employ a capture protocol to select these sites and perform targeted methylation sequencing. Multi-modal information about the DNA methylation patterns are then utilized in machine learning algorithms trained to predict disease status and disease progression. We applied our method to two independent cohorts of ALS patients and controls (n=192). Overall, we found that the targeted sites accurately predicted ALS status and replicated between cohorts. Additionally, we identified epigenetic features associated with ALS phenotypes, including disease severity. These findings highlight the potential of cfDNA as a non-invasive biomarker for ALS.

2.
Mol Psychiatry ; 28(6): 2301-2311, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37173451

RESUMO

BACKGROUND: Alterations in brain connectivity may underlie neuropsychiatric conditions such as schizophrenia. We here assessed the degree of convergence of frontostriatal fiber projections in 56 young adult healthy controls (HCs) and 108 matched Early Psychosis-Non-Affective patients (EP-NAs) using our novel fiber cluster analysis of whole brain diffusion magnetic resonance imaging tractography. METHODS: Using whole brain tractography and our fiber clustering methodology on harmonized diffusion magnetic resonance imaging data from the Human Connectome Project for Early Psychosis we identified 17 white matter fiber clusters that connect frontal cortex (FCtx) and caudate (Cd) per hemisphere in each group. To quantify the degree of convergence and, hence, topographical relationship of these fiber clusters, we measured the inter-cluster mean distances between the endpoints of the fiber clusters at the level of the FCtx and of the Cd, respectively. RESULTS: We found (1) in both groups, bilaterally, a non-linear relationship, yielding convex curves, between FCtx and Cd distances for FCtx-Cd connecting fiber clusters, driven by a cluster projecting from inferior frontal gyrus; however, in the right hemisphere, the convex curve was more flattened in EP-NAs; (2) that cluster pairs in the right (p = 0.03), but not left (p = 0.13), hemisphere were significantly more convergent in HCs vs EP-NAs; (3) in both groups, bilaterally, similar clusters projected significantly convergently to the Cd; and, (4) a significant group by fiber cluster pair interaction for 2 right hemisphere fiber clusters (numbers 5, 11; p = .00023; p = .00023) originating in selective PFC subregions. CONCLUSIONS: In both groups, we found the FCtx-Cd wiring pattern deviated from a strictly topographic relationship and that similar clusters projected significantly more convergently to the Cd. Interestingly, we also found a significantly more convergent pattern of connectivity in HCs in the right hemisphere and that 2 clusters from PFC subregions in the right hemisphere significantly differed in their pattern of connectivity between groups.


Assuntos
Transtornos Psicóticos , Substância Branca , Adulto Jovem , Humanos , Voluntários Saudáveis , Cádmio , Substância Branca/patologia , Encéfalo/patologia , Transtornos Psicóticos/diagnóstico por imagem , Transtornos Psicóticos/patologia
3.
Orphanet J Rare Dis ; 17(1): 305, 2022 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-35907869

RESUMO

BACKGROUND: The Hermansky-Pudlak syndrome (HPS) is a genetically heterogeneous group of diseases characterized by oculocutaneous albinism, bleeding diathesis, and systemic complications. It is the most common genetic disorder in Puerto Rico. These patients are at a significant risk of developing a variety of skin complications and little is known about the prevalence of dermatologic diagnoses in this population. OBJECTIVES: To report dermatologic manifestations in patients with Hermansky-Pudlak syndrome (HPS). Secondary aims include skin concerns, sun protection habits, barriers to dermatologic care, and skin cancer knowledge. METHODS: Cross-sectional study with twenty-nine Puerto Rican patients who carried a clinical diagnosis of HPS type 1 or type 3 through a telephonic questionnaire. RESULTS: Twenty-nine patients participated with a mean (SD) age of 37.3 (16.8) years and the majority were female (69%). The most common diagnoses were skin cancer (34.5%), acne (34.5%), bacterial skin infections (34.5%), warts (24%), urticaria (17.2%), and psoriasis (17.2%). The most common skin concerns were dry skin (62.1%), hair loss (58.9%), redness (34.5%), moles (31%), and rash (31%). The most common sun protection behavior was wearing a shirt that covers the shoulders (93.1%, often or always) and the least common was wearing a hat (24.1%, often or always). Higher income was significantly associated with being more likely to use sunscreen often or always (OR = 3.38, 95% CI 1.02-11.18, p = 0.04). Those in northern urban areas were significantly less likely to report barriers to dermatologic care (OR = 0.13, 95% CI 0.02-0.76, p = 0.02). CONCLUSIONS: This study provides an important overview of the most common self-reported skin manifestations in patients with HPS. Unfortunately, a high prevalence of cutaneous malignancy was reported. The results stress the need for adequate care and potential interventions to promote sun protection behaviors and skin cancer prevention.


Assuntos
Albinismo , Síndrome de Hermanski-Pudlak , Neoplasias Cutâneas , Adulto , Estudos Transversais , Feminino , Transtornos Hemorrágicos , Síndrome de Hermanski-Pudlak/diagnóstico , Síndrome de Hermanski-Pudlak/epidemiologia , Humanos , Masculino , Neoplasias Cutâneas/complicações
4.
P R Health Sci J ; 41(1): 45-48, 2022 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-35438896

RESUMO

Localized scleroderma (LS) is a rare fibrosing disorder of skin and underlying tissues. Although it can affect all races, it has a higher prevalence in whites. Deep LS is the least common among seven LS variants, representing less than 5% of cases, and typically affects areas of pressure such as the hips and waist. We report a unique clinical case of bilateral lower extremity deep LS in a 51-year-old Puerto Rican woman with chronic kidney disease (CKD). In patients with CKD, it is important to distinguish LS from nephrogenic systemic fibrosis (NSF). Both can present with skin fibrosis and contractures over joints yet have significantly differing treatment approaches and prognosis. Our case report is unique due to the patient's Puerto Rican ethnicity, CKD history, and isolated anterior lower extremity involvement. In this report, we highlight key clinical and histopathological findings of LS, and how they differ from that of NSF.


Assuntos
Dermopatia Fibrosante Nefrogênica , Insuficiência Renal Crônica , Esclerodermia Localizada , Dermatopatias , Meios de Contraste , Progressão da Doença , Feminino , Gadolínio , Humanos , Masculino , Pessoa de Meia-Idade , Dermopatia Fibrosante Nefrogênica/etiologia , Dermopatia Fibrosante Nefrogênica/patologia , Dermopatia Fibrosante Nefrogênica/terapia , Insuficiência Renal Crônica/complicações , Esclerodermia Localizada/complicações
5.
Cereb Cortex ; 31(12): 5308-5318, 2021 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-34180506

RESUMO

To assess normal organization of frontostriatal brain wiring, we analyzed diffusion magnetic resonance imaging (dMRI) scans in 100 young adult healthy subjects (HSs). We identified fiber clusters intersecting the frontal cortex and caudate, a core component of associative striatum, and quantified their degree of deviation from a strictly topographic pattern. Using whole brain dMRI tractography and an automated tract parcellation clustering method, we extracted 17 white matter fiber clusters per hemisphere connecting the frontal cortex and caudate. In a novel approach to quantify the geometric relationship among clusters, we measured intercluster endpoint distances between corresponding cluster pairs in the frontal cortex and caudate. We show first, the overall frontal cortex wiring pattern of the caudate deviates from a strictly topographic organization due to significantly greater convergence in regionally specific clusters; second, these significantly convergent clusters originate in subregions of ventrolateral, dorsolateral, and orbitofrontal prefrontal cortex (PFC); and, third, a similar organization in both hemispheres. Using a novel tractography method, we find PFC-caudate brain wiring in HSs deviates from a strictly topographic organization due to a regionally specific pattern of cluster convergence. We conjecture cortical subregions projecting to the caudate with greater convergence subserve functions that benefit from greater circuit integration.


Assuntos
Imagem de Tensor de Difusão , Substância Branca , Encéfalo/diagnóstico por imagem , Análise por Conglomerados , Imagem de Tensor de Difusão/métodos , Voluntários Saudáveis , Humanos , Vias Neurais/diagnóstico por imagem , Vias Neurais/patologia , Substância Branca/diagnóstico por imagem , Adulto Jovem
6.
Mol Carcinog ; 57(11): 1616-1625, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30074276

RESUMO

Although genetic amplification and overexpression of the fibroblast growth factor 19 (FGF19) gene are found in human breast cancer, mechanisms that contribute to such functional alterations remain elusive. We report here that high expression of FGF19 is associated with the aggressive malignant behavior and poor survival outcome of breast cancer patients. FGF19 is particularly highly expressed in luminal molecular subtype of breast tumors and its expression levels are positively associated with its secretion levels from breast cancer cells. Genetic knockout of FGF19 significantly induces repression of breast tumor progression and metastasis in either an orthotopic mouse model of breast cancer or an experimental metastasis model. The FGF19 specific receptor, FGFR4, can be activated and subsequently upregulate AKT signaling in breast cancer cell upon FGF19, which is critical for oncogenic role of FGF19. Inactivation of FGFR4 by its inhibitor BLU9931 significantly attenuates FGF19-induced tumor-promoting activity, suggesting interruption of FGFR4 function is sufficient to affect FGF19-driven breast cancer. Overall, these insights support the idea that targeting FGFR4 in breast cancer cells overexpressing FGF19 may represent an effective strategy to suppress cancer development, progression, and metastasis.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Fatores de Crescimento de Fibroblastos/metabolismo , Receptor Tipo 4 de Fator de Crescimento de Fibroblastos/metabolismo , Transdução de Sinais , Adulto , Idoso , Animais , Biomarcadores , Neoplasias da Mama/genética , Neoplasias da Mama/mortalidade , Linhagem Celular Tumoral , Modelos Animais de Doenças , Progressão da Doença , Feminino , Fatores de Crescimento de Fibroblastos/genética , Deleção de Genes , Marcação de Genes , Humanos , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/secundário , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Eur J Neurol ; 25(10): 1201-1217, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29932266

RESUMO

BACKGROUND AND PURPOSE: Recommendations for using fluorodeoxyglucose positron emission tomography (FDG-PET) to support the diagnosis of dementing neurodegenerative disorders are sparse and poorly structured. METHODS: Twenty-one questions on diagnostic issues and on semi-automated analysis to assist visual reading were defined. Literature was reviewed to assess study design, risk of bias, inconsistency, imprecision, indirectness and effect size. Critical outcomes were sensitivity, specificity, accuracy, positive/negative predictive value, area under the receiver operating characteristic curve, and positive/negative likelihood ratio of FDG-PET in detecting the target conditions. Using the Delphi method, an expert panel voted for/against the use of FDG-PET based on published evidence and expert opinion. RESULTS: Of the 1435 papers, 58 papers provided proper quantitative assessment of test performance. The panel agreed on recommending FDG-PET for 14 questions: diagnosing mild cognitive impairment due to Alzheimer's disease (AD), frontotemporal lobar degeneration (FTLD) or dementia with Lewy bodies (DLB); diagnosing atypical AD and pseudo-dementia; differentiating between AD and DLB, FTLD or vascular dementia, between DLB and FTLD, and between Parkinson's disease and progressive supranuclear palsy; suggesting underlying pathophysiology in corticobasal degeneration and progressive primary aphasia, and cortical dysfunction in Parkinson's disease; using semi-automated assessment to assist visual reading. Panellists did not support FDG-PET use for pre-clinical stages of neurodegenerative disorders, for amyotrophic lateral sclerosis and Huntington disease diagnoses, and for amyotrophic lateral sclerosis or Huntington-disease-related cognitive decline. CONCLUSIONS: Despite limited formal evidence, panellists deemed FDG-PET useful in the early and differential diagnosis of the main neurodegenerative disorders, and semi-automated assessment helpful to assist visual reading. These decisions are proposed as interim recommendations.


Assuntos
Encéfalo/diagnóstico por imagem , Disfunção Cognitiva/diagnóstico por imagem , Demência/diagnóstico por imagem , Fluordesoxiglucose F18 , Doenças Neurodegenerativas/diagnóstico por imagem , Tomografia por Emissão de Pósitrons/métodos , Consenso , Diagnóstico Diferencial , Humanos , Medicina Nuclear , Sensibilidade e Especificidade
8.
Migr Stud ; 6(1): 120-139, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38250581

RESUMO

Hondurans have been targeted for deportation since the 1980s, but today their deportations have grown disproportionate to their immigrant population size. They are more likely to face deportation than other targeted groups, such as Mexicans, Salvadorans and Guatemalans. Given Hondurans' singular position in the deportation system and the dearth of research about this group, we ask: What are the potential short- and long-term consequences of deportation for Honduran migrants, their families, and the broader community? To address this question, we utilize qualitative interviews with deportees, their families, and community members collected in Honduras in 2011 and 2014 as part of a multi-country research project our team conducted on the social impacts of deportations. While our findings in Honduras parallel those in other studies, we capture economic, social, and emotional effects beyond the individual deportees, including non-migrant family members and the broader community that receives them. Our longitudinal approach allows us to capture re-migration patterns as well.

10.
AJNR Am J Neuroradiol ; 38(5): 954-960, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28341715

RESUMO

BACKGROUND AND PURPOSE: Primary-progressive aphasia is a clinically and pathologically heterogeneous condition. Nonfluent, semantic, and logopenic are the currently recognized clinical variants. The recommendations for the classification of primary-progressive aphasia have advocated variant-specific patterns of atrophy. The aims of the present study were to evaluate the sensitivity and specificity of the proposed imaging criteria and to assess the intra- and interrater reporting agreements. MATERIALS AND METHODS: The cohort comprised 51 patients with a root diagnosis of primary-progressive aphasia, 25 patients with typical Alzheimer disease, and 26 matched control participants. Group-level analysis (voxel-based morphometry) confirmed the proposed atrophy patterns for the 3 syndromes. The individual T1-weighted anatomic images were reported by 3 senior neuroradiologists. RESULTS: We observed a dichotomized pattern of high sensitivity (92%) and specificity (93%) for the proposed atrophy pattern of semantic-variant primary-progressive aphasia and low sensitivity (21% for nonfluent-variant primary-progressive aphasia and 43% for logopenic-variant primary-progressive aphasia) but high specificity (91% for nonfluent-variant primary-progressive aphasia and 95% for logopenic-variant primary-progressive aphasia) in other primary-progressive aphasia variants and Alzheimer disease (sensitivity 43%, specificity 92%). MR imaging was least sensitive for the diagnosis of nonfluent-variant primary-progressive aphasia. Intrarater agreement analysis showed mean κ values above the widely accepted threshold of 0.6 (mean, 0.63 ± 0.16). Pair-wise interobserver agreement outcomes, however, were well below this threshold in 5 of the 6 possible interrater contrasts (mean, 0.41 ± 0.09). CONCLUSIONS: While the group-level results were in precise agreement with the recommendations, semantic-variant primary-progressive aphasia was the only subtype for which the proposed recommendations were both sensitive and specific at an individual level.


Assuntos
Afasia Primária Progressiva/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Neuroimagem/métodos , Idoso , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade
11.
J Clin Neurosci ; 21(1): 165-7, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24035425

RESUMO

The behavioural variant of frontotemporal dementia (bvFTD) is characterised by personality change with a decline in cognition. We describe two patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukencephalopathy (CADASIL) who presented with behavioural phenotypes similar to bvFTD. The first patient presented with progressive personality and behavioural change, had florid white matter hyperintensity, and had a novel missense mutation C366W in exon 7 of the Notch3 gene. The second patient presented with progressive memory impairment and marked personality changes after a transient ischaemic attack. In this second patient, the radiological features were subtle and only the family history of stroke prompted testing for CADASIL using Notch3 genotyping. We present these patients to demonstrate that CADASIL may mimic bvFTD, with little clinical or radiological evidence to distinguish the two. CADASIL may be an under-recognised diagnosis in apparent bvFTD. Screening Notch3 in a substantial and unselected cohort of frontotemporal dementia patients might be appropriate to investigate this possibility.


Assuntos
CADASIL/diagnóstico , Demência Frontotemporal/diagnóstico , Idoso , CADASIL/genética , CADASIL/psicologia , Diagnóstico Diferencial , Feminino , Demência Frontotemporal/psicologia , Humanos , Pessoa de Meia-Idade , Fenótipo , Receptor Notch3 , Receptores Notch/genética
12.
Psychol Med ; 43(3): 603-18, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22781212

RESUMO

BACKGROUND: Schizophrenia is characterized by deficits in emotional prosody (EP) perception. However, it is not clear which stages of processing prosody are abnormal and whether the presence of semantic content contributes to the abnormality. This study aimed to examine event-related potential (ERP) correlates of EP processing in 15 chronic schizophrenia individuals and 15 healthy controls. METHOD: A total of 114 sentences with neutral semantic content [sentences with semantic content (SSC) condition] were generated by a female speaker (38 with happy, 38 with angry, and 38 with neutral intonation). The same sentences were synthesized and presented in the 'pure prosody' sentences (PPS) condition where semantic content was unintelligible. RESULTS: Group differences were observed for N100 and P200 amplitude: patients were characterized by more negative N100 for SSC, and more positive P200 for angry and happy SSC and happy PPS. Correlations were found between delusions and P200 amplitude for happy SSC and PPS. Higher error rates in the recognition of EP were also observed in schizophrenia: higher error rates in neutral SSC were associated with reduced N100, and higher error rates in angry SSC were associated with reduced P200. CONCLUSIONS: These results indicate that abnormalities in prosody processing occur at the three stages of EP processing, and are enhanced in SSC. Correlations between P200 amplitude for happy prosody and delusions suggest a role that abnormalities in the processing of emotionally salient acoustic cues may play in schizophrenia symptomatology. Correlations between ERP and behavioral data point to a relationship between early sensory abnormalities and prosody recognition in schizophrenia.


Assuntos
Encéfalo/fisiopatologia , Emoções/fisiologia , Potenciais Evocados Auditivos/fisiologia , Esquizofrenia/fisiopatologia , Psicologia do Esquizofrênico , Percepção da Fala/fisiologia , Estimulação Acústica/métodos , Adulto , Estudos de Casos e Controles , Sinais (Psicologia) , Delusões/fisiopatologia , Eletroencefalografia/estatística & dados numéricos , Feminino , Lateralidade Funcional , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Percepção da Altura Sonora/fisiologia , Escalas de Graduação Psiquiátrica , Psicopatologia , Tempo de Reação/fisiologia , Semântica
13.
Eur J Neurol ; 19(12): e131-40, 1487-501, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22900895

RESUMO

BACKGROUND AND PURPOSE: The European Federation of the Neurological Societies (EFNS) guidelines on the use of neuroimaging in the diagnosis and management of dementia are designed to revise and expand previous EFNS recommendations for the diagnosis and management of patients with Alzheimer's disease (AD) and to provide an overview of the evidence for the use of neuroimaging techniques in non-AD dementias, as well as general recommendations that apply to all types of dementia in clinical practice. METHODS: The task force working group reviewed evidence from original research articles, meta-analyses and systematic reviews, published before April 2012. The evidence was classified, and consensus recommendations were given and graded according to the EFNS guidance regulations. RESULTS: Structural imaging, which should be performed at least once in the diagnostic work-up of patients with cognitive impairment, serves to exclude other potentially treatable diseases, to recognize vascular lesions and to identify specific findings to help distinguish different forms of neurodegenerative types of dementia. Although typical cases of dementia may not benefit from routine functional imaging, these tools are recommended in those cases where diagnosis remains in doubt after clinical and structural imaging work-up and in particular clinical settings. Amyloid imaging is likely to find clinical utility in several fields, including the stratification of patients with mild cognitive impairment into those with and without underlying AD and the evaluation of atypical AD presentations. CONCLUSIONS: A number of recommendations and good practice points are made to improve the diagnosis of AD and other dementias.


Assuntos
Demência/diagnóstico , Neuroimagem/métodos , Comitês Consultivos , Doença de Alzheimer/diagnóstico , Humanos
14.
Neurology ; 78(21): 1670-7, 2012 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-22573633

RESUMO

OBJECTIVE: Primary progressive aphasia (PPA) has been proposed to comprise 3 discrete clinical subtypes: semantic, agrammatic/nonfluent, and logopenic. Recent consensus recommendations suggest a diagnostic framework based primarily on clinical and neuropsychological findings to classify these variants. Our objective was to evaluate the extent to which patients with PPA would conform to the proposed tripartite system and whether the clustering pattern of elements of the linguistic profile suggests discrete clinical syndromes. METHODS: A total of 46 patients with PPA were prospectively recruited to the Cambridge Longitudinal Study of PPA. Sufficient data were collected to assess all consensus-proposed diagnostic domains. By comparing patients' performances against those of 30 age- and education-matched healthy volunteers, z scores were calculated, and values of 1.5 SDs outside control participants' means were considered abnormal. Raw test scores were used to undertake a principal factor analysis to identify the clustering pattern of individual measures. RESULTS: Of the patients, 28.3%, 26.1%, and 4.3% fitted semantic, nonfluent/agrammatic, and logopenic categories respectively, and 41.3% did not fulfill the diagnostic recommendations for any of the 3 proposed variants. There was no significant between-group difference in age, education, or disease duration. Furthermore, the outcome of the factor analysis was in keeping with discrete semantic and nonfluent/agrammatic syndromes but did not support a logopenic variant. CONCLUSION: Taken together, the results of this prospective data-driven study suggest that although a substantial proportion of patients with PPA have neither the semantic nor the nonfluent variants, they do not necessarily conform to a discrete logopenic variant.


Assuntos
Afasia Primária Progressiva/classificação , Afasia Primária Progressiva/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Humanos , Estudos Longitudinais , Pessoa de Meia-Idade , Testes Neuropsicológicos , Afasia Primária Progressiva não Fluente/diagnóstico , Estudos Prospectivos , Síndrome
16.
Neuropsychologia ; 49(9): 2694-702, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21658396

RESUMO

Episodic autobiographical memory (ABM) comprises recollection for events that are grounded within a specific spatiotemporal context, and usually accompanied by perceptual and emotional information. The neural substrates mediating ABM retrieval are those harbouring significant pathology in semantic dementia (SD) and behavioural-variant frontotemporal dementia (bvFTD), the most common subtypes of FTD. Relatively little is known, however, regarding the differential patterns of contextual details during episodic ABM retrieval across these dementia syndromes. This study investigated episodic ABM retrieval under free and probed recall conditions from 4 time periods with the aim to identify disease-specific profiles of episodic ABM contextual details. Episodic ABM was measured in 25 SD and 15 bvFTD patients and their performance contrasted to that of 17 Alzheimer's disease (AD) patients and 19 age-matched controls. Critically, SD patients showed relatively preserved recent ABM in comparison with remote epochs. In contrast, bvFTD and AD patients showed a reduced capacity to recall specific and contextually rich ABMs across all life epochs, in both free and probed recall conditions. Analyses of the recent period (last 12 months) provided evidence for different profiles of contextual episodic details recalled in dementia syndromes. Following probing, SD patients' recall deficits emanated exclusively from compromised Emotion/Thoughts and Spatiotemporal details. In contrast, bvFTD patients were significantly impaired across all categories of contextual details whereas AD patients showed deficits for Event and Emotion/Thoughts details only. As the largest study of ABM in FTD to date, these findings emphasise the differential impairment of recent ABM contextual details contingent on the underlying disease pathology. In addition, these results point towards the importance of investigating the constituent elements of emotion processing and strategic retrieval processes as potential variables mediating recent episodic ABM retrieval.


Assuntos
Doença de Alzheimer/complicações , Demência Frontotemporal/complicações , Degeneração Lobar Frontotemporal/complicações , Transtornos da Memória/classificação , Memória Episódica , Idoso , Análise de Variância , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Transtornos da Memória/complicações , Transtornos da Memória/diagnóstico , Pessoa de Meia-Idade , Valores de Referência
17.
Schizophr Res ; 123(2-3): 153-9, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20822884

RESUMO

The dorsolateral prefrontal cortex (DLPFC) is a brain region that has figured prominently in studies of schizophrenia and working memory, yet the exact neuroanatomical localization of this brain region remains to be defined. DLPFC primarily involves the superior frontal gyrus and middle frontal gyrus (MFG). The latter, however is not a single neuroanatomical entity but instead is comprised of rostral (anterior, middle, and posterior) and caudal regions. In this study we used structural MRI to develop a method for parcellating MFG into its component parts. We focused on this region of DLPFC because it includes BA46, a region involved in working memory. We evaluated volume differences in MFG in 20 patients with chronic schizophrenia and 20 healthy controls. Mid-rostral MFG (MR-MFG) was delineated within the rostral MFG using anterior and posterior neuroanatomical landmarks derived from cytoarchitectonic definitions of BA46. Gray matter volumes of MR-MFG were then compared between groups, and a significant reduction in gray matter volume was observed (p<0.008), but not in other areas of MFG (i.e., anterior or posterior rostral MFG, or caudal regions of MFG). Our results demonstrate that volumetric alterations in MFG gray matter are localized exclusively to MR-MFG. 3D reconstructions of the cortical surface made it possible to follow MFG into its anterior part, where other approaches have failed. This method of parcellation offers a more precise way of measuring MR-MFG that will likely be important in further documentation of DLPFC anomalies in schizophrenia.


Assuntos
Lobo Frontal/patologia , Imageamento por Ressonância Magnética , Esquizofrenia/patologia , Adulto , Estudos de Casos e Controles , Doença Crônica , Manual Diagnóstico e Estatístico de Transtornos Mentais , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Córtex Pré-Frontal/patologia
18.
Neurology ; 74(6): 472-9, 2010 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-20142613

RESUMO

OBJECTIVE: Studies have shown variable memory performance in patients with behavioral variant frontotemporal dementia (bvFTD). Our study investigated whether this variability is due to the admixture of patients with true bvFTD and phenocopy patients. We also sought to compare performance of patients with bvFTD and patients with Alzheimer disease (AD). METHODS: We analyzed neuropsychological memory performance in patients with a clinical diagnosis of bvFTD divided into those who progressed (n = 50) and those who remained stable (n = 39), patients with AD (n = 64), and healthy controls (n = 64). RESULTS: Patients with progressive bvFTD were impaired on most memory tests to a similar level to that of patients with early AD. Findings from a subset of patients with progressive bvFTD with confirmed FTLD pathology (n = 10) corroborated these findings. By contrast, patients with phenocopy bvFTD performed significantly better than progressors and patients with AD. Logistic regression revealed that patients with bvFTD can be distinguished to a high degree (85%) on the immediate recall score of a word list learning test (Rey Auditory Verbal Learning Test). CONCLUSIONS: Our results provide evidence for an underlying memory deficit in "real" or progressive behavioral variant frontotemporal dementia (bvFTD) similar to Alzheimer disease, though the groups differ in orientation scores, with patients with bvFTD being intact. Exclusion solely based on impaired neuropsychological memory performance can potentially lead to an underdiagnosis of FTD.


Assuntos
Doença de Alzheimer/complicações , Demência Frontotemporal/complicações , Transtornos da Memória/etiologia , Rememoração Mental/fisiologia , Idoso , Cognição/fisiologia , Feminino , Humanos , Modelos Logísticos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Tomografia por Emissão de Pósitrons/métodos , Estatística como Assunto
19.
Neuroimage ; 49(3): 2205-15, 2010 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-19892022

RESUMO

Voxel-based morphometry studies are frequently cited as having the advantage of being objective compared to region-of-interest methods. This statement assumes, however, that all regions are treated equally both in controls and diseased cohorts. This study aimed to test whether this statement is correct by analyzing fiducial landmarks in controls, Alzheimer's disease (as a model of mild generalized atrophy model); Frontotemporal Dementia (focal atrophy model) and Semantic Dementia (extreme focal atrophy model). Standard SPM5 and DARTEL were evaluated using either raw or skull-stripped/bias corrected scans. The results indicated that with all methods there was variability in the degree of misregistration across regions and that there was a disease grouping interaction-most severely in the extreme focal atrophy model (Semantic Dementia). Preprocessing improved VBM outputs both with standard SPM and DARTEL. In the latter case, this occurred to an extreme degree-DARTEL using raw data was grossly insensitive to a ground truth (manually verified hippocampal atrophy in AD) whereas DARTEL after preprocessing yielded excellent results with respect to this yardstick.


Assuntos
Encéfalo/patologia , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética , Idoso , Doença de Alzheimer/patologia , Feminino , Demência Frontotemporal/patologia , Degeneração Lobar Frontotemporal/patologia , Humanos , Masculino , Pessoa de Meia-Idade
20.
Int J Psychophysiol ; 75(2): 133-40, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19840822

RESUMO

Abnormal language in schizophrenia has been regarded as a hallmark of this disorder. Language abnormalities include loose and unusual associations, tangentiality, and inability to maintain a topic. Recent theories of language dysfunction have invoked working memory abnormalities, as well as abnormal processes within semantic memory in schizophrenia. Two views, often construed as opposing, have been offered to account for language peculiarities in schizophrenia: one holds that initial processes of activation are abnormal while the other holds that late processes of context utilization might be disturbed. We suggest that these views may be complementary rather than mutually exclusive. Given the relative paucity of data on the early processes within semantic networks, we present new evidence using ERP short SOA paradigm that these processes are abnormal in schizophrenia. Furthermore, reduced N400 in the unrelated condition found in this study suggests that the abnormality was related to inefficient early inhibitory processes.


Assuntos
Potenciais Evocados/fisiologia , Inibição Psicológica , Rede Nervosa/fisiopatologia , Esquizofrenia/fisiopatologia , Psicologia do Esquizofrênico , Semântica , Adulto , Análise de Variância , Córtex Cerebral/fisiologia , Eletroencefalografia , Humanos , Idioma , Masculino , Rememoração Mental/fisiologia , Pessoa de Meia-Idade , Testes Neuropsicológicos , Tempo de Reação/fisiologia
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