RESUMO
The neurofunctional effects of Cognitive training (CT) are poorly understood. Our main objective was to assess fMRI brain activation patterns in children with ADHD who received CT as an add-on treatment to stimulant medication. We included twenty children with ADHD from a clinical trial of stimulant medication and CT (10 in medication + CT and 10 in medication + non-active training). Between-group differences were assessed in performance and in brain activation during 3 fMRI paradigms of working memory (N-back: 0-back, 1-back, 2-back, 3-back), sustained attention (Sustained Attention Task - SAT: 2 s, 5 s and 8 s delays) and inhibitory control (Go/No-Go). We found significant group x time x condition interactions in working memory (WM) and sustained attention on brain activation. In N-back, decreases were observed in the BOLD signal change from baseline to endpoint with increasing WM load in the right insula, right putamen, left thalamus and left pallidum in the CT compared to the non-active group; in SAT - increases in the BOLD signal change from baseline to endpoint with increasing delays were observed in bilateral precuneus, right insula, bilateral associative visual cortex and angular gyrus, right middle temporal, precentral, postcentral, superior frontal and middle frontal gyri in the CT compared to the non-active group. CT in ADHD was associated with changes in activation in task-relevant parietal and striato-limbic regions of sustained attention and working memory. Changes in brain activity may precede behavioral performance modifications in working memory and sustained attention, but not in inhibitory control.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/diagnóstico por imagem , Transtorno do Deficit de Atenção com Hiperatividade/tratamento farmacológico , Encéfalo/diagnóstico por imagem , Estimulantes do Sistema Nervoso Central/uso terapêutico , Cognição , Remediação Cognitiva , Imageamento por Ressonância Magnética , Terapia Assistida por Computador , Atenção/efeitos dos fármacos , Atenção/fisiologia , Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Criança , Cognição/efeitos dos fármacos , Cognição/fisiologia , Feminino , Humanos , Masculino , Memória de Curto Prazo/efeitos dos fármacos , Memória de Curto Prazo/fisiologia , Projetos PilotoRESUMO
The goal of the present study was to investigate intrinsic and reading-related brain function associated with dyslexia and typical readers in monolingual Brazilian children. Two fMRI studies were carried out: a resting-state and a word-reading study. The results show (a) underconnectivity between the occipitotemporal region (visual word form area) and the brain's default-mode network in dyslexic readers and (b) more activation of the anterior cingulate cortex for typical readers relative to dyslexic readers. The findings provide evidence for brain connectivity and function differences in an underrepresented population in fMRI studies of dyslexia; the results suggest atypical intrinsic function, and differences in directed attention processes in dyslexia.
Assuntos
Mapeamento Encefálico/métodos , Encéfalo/diagnóstico por imagem , Córtex Cerebral/fisiopatologia , Dislexia/fisiopatologia , Giro do Cíngulo/fisiopatologia , Imageamento por Ressonância Magnética/métodos , Neuroimagem/métodos , Leitura , Adolescente , Criança , Feminino , Humanos , MasculinoRESUMO
Acidente vascular cerebral é uma emergência médica de alta morbimortalidade cuja conduta depende do tempo de início dos sintomas, da agilidade diagnóstica e de técnicas de neuroimagem. Diferenciar quadros isquêmicos de hemorrágicos com a tomografia computadorizada (TC) de crânio com contraste é fundamental para definir tratamento.
Stroke is a medical emergency with a high rate of morbidity and mortality in which treatment depends on the onset of the symptoms, on the diagnostic agility and on neuroimaging technics. Differentiation between ischemic and hemorrhagic type of stroke using a non-contrast CT scan of the brain is very important to define treatment.
Assuntos
Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/epidemiologia , EmergênciasRESUMO
Delirium é um estado confusional agudo, patologia neuropsiquiátrica de forte importância em contexto emergencial e frequentemente subdiagnosticada. De etiologia variada, os pacientes com delirium devem receber manejo imediato e investigação causal básica para resolução completa do quadro.
Delirium is an acute confusional state, a neuropsychiatric pathology with great importance in the emergency department and frequently underdiagnosed. With multiple etiology, patients with delirium should receive immediate management and workup for complete clinical resolution.
Assuntos
Delírio/diagnóstico , Idoso , Serviços Médicos de Emergência , Manifestações NeurocomportamentaisRESUMO
Healthy neuronal function and synaptic modification require a concert of synthesis and degradation of proteins. Increasing evidence indicates that protein turnover mediated by proteasome activity is involved in long-term synaptic plasticity and memory. However, its role in different phases of memory remains debated, and previous studies have not examined the possible requirement of protein degradation in recognition memory. Here, we show that the proteasome inhibitor, lactacystin (LAC), infused into the CA1 area of the hippocampus at two specific time points during consolidation, impairs 24-retention of memory for object recognition in rats. Administration of LAC after retrieval did not affect retention. These findings provide the first evidence for a requirement of proteasome activity in recognition memory, indicate that protein degradation in the hippocampus is necessary during selective time windows of memory consolidation, and further our understanding of the role of protein turnover in memory formation.