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1.
Neuroendocrinology ; 114(4): 348-355, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38169458

RESUMO

INTRODUCTION: Hyperthyroidism, characterized by excessive thyroid hormone production, is a common endocrine disorder that affects various physiological processes, including brain function. Recent advancements in neuroimaging techniques have enabled researchers to investigate structural alterations in the brain associated with hyperthyroidism. This study aimed to examine regional cortical thickness and cortical volume differences across the brain between hyperthyroid patients and control subjects. METHODS: We examined localized cortical thicknesses and volumes in 34 hyperthyroid patients and 35 control subjects with high-resolution T1-weighted images using FreeSurfer software and assessed group differences with analysis of covariance (covariates: age, sex, education, and total intracranial volume). Spearman and partial correlations were performed between clinical variables and cortical thicknesses/volumes and between neuropsychological scores and cortical thicknesses/volumes, respectively. RESULTS: Hyperthyroid patients exhibited significantly increased cortical thickness in bilateral superior temporal and superior frontal gyri, along with higher cortical volumes in various regions, including the right superior temporal gyrus, right superior parietal gyrus, right rostral and caudal middle frontal gyrus, and left superior frontal gyrus. Notably, thyroid hormones (fT3, fT4) correlated positively with cortical thicknesses and volumes in the superior temporal gyrus and superior frontal gyrus. Additionally, recognition memory scores negatively correlated with the right superior temporal gyrus and right superior frontal gyrus cortical thickness. CONCLUSION: The observed cortical thickening and increased cortical volume in specific brain areas provide new insights into the pathophysiological mechanism associated with brain impairment in hyperthyroidism.


Assuntos
Substância Cinzenta , Hipertireoidismo , Humanos , Substância Cinzenta/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Encéfalo , Córtex Pré-Frontal
2.
Brain Connect ; 13(10): 598-609, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37847159

RESUMO

Background: Individual differences exist in performance in tasks that require visual search, such as camouflage detection (CD). Field dependence/independence (FD/I), as assessed using the Group Embedded Figures Test (GEFT), is an extensively studied dimension of cognitive style that classifies participants based on their visual perceptual styles. Materials and Methods: In the present study, we utilized fMRI on 46 healthy participants to investigate the underlying neural mechanisms specific to the cognitive styles of FD/FI while performing a CD task using both activation magnitude and an exploratory functional connectivity (FC) analysis. Group differences between high and low performers on the two extremes of the accuracy continuum of GEFT were studied. Results: No statistically significant group differences were observed using whole-brain voxel-wise comparison. However, the exploratory FC analysis revealed an enhanced communication between various regions subserving the cognitive traits required for visual search by FI participants over and above their FD counterparts. Conclusion: These enhanced connectivities suggest additional recruitment of cognitive functions to provide computational support that might facilitate superior performance in CD task by the participants who display a field-independent cognitive style.


Assuntos
Encéfalo , Imageamento por Ressonância Magnética , Humanos , Encéfalo/diagnóstico por imagem , Cognição/fisiologia , Personalidade , Individualidade
3.
Neuroimage Clin ; 38: 103387, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37023491

RESUMO

Despite the effectiveness of surgical interventions for the treatment of intractable focal temporal lobe epilepsy (TLE), the substrates that support good outcomes are poorly understood. While algorithms have been developed for the prediction of either seizure or cognitive/psychiatric outcomes alone, no study has reported on the functional and structural architecture that supports joint outcomes. We measured key aspects of pre-surgical whole brain functional/structural network architecture and evaluated their ability to predict post-operative seizure control in combination with cognitive/psychiatric outcomes. Pre-surgically, we identified the intrinsic connectivity networks (ICNs) unique to each person through independent component analysis (ICA), and computed: (1) the spatial-temporal match between each person's ICA components and established, canonical ICNs, (2) the connectivity strength within each identified person-specific ICN, (3) the gray matter (GM) volume underlying the person-specific ICNs, and (4) the amount of variance not explained by the canonical ICNs for each person. Post-surgical seizure control and reliable change indices of change (for language [naming, phonemic fluency], verbal episodic memory, and depression) served as binary outcome responses in random forest (RF) models. The above functional and structural measures served as input predictors. Our empirically derived ICN-based measures customized to the individual showed that good joint seizure and cognitive/psychiatric outcomes depended upon higher levels of brain reserve (GM volume) in specific networks. In contrast, singular outcomes relied on systematic, idiosyncratic variance in the case of seizure control, and the weakened pre-surgical presence of functional ICNs that encompassed the ictal temporal lobe in the case of cognitive/psychiatric outcomes. Our data made clear that the ICNs differed in their propensity to provide reserve for adaptive outcomes, with some providing structural (brain), and others functional (cognitive) reserve. Our customized methodology demonstrated that when substantial unique, patient-specific ICNs are present prior to surgery there is a reliable association with poor post-surgical seizure control. These ICNs are idiosyncratic in that they did not match the canonical, normative ICNs and, therefore, could not be defined functionally, with their location likely varying by patient. This important finding suggested the level of highly individualized ICN's in the epileptic brain may signal the emergence of epileptogenic activity after surgery.


Assuntos
Epilepsia do Lobo Temporal , Memória Episódica , Humanos , Imageamento por Ressonância Magnética/métodos , Rede Nervosa , Encéfalo/diagnóstico por imagem , Encéfalo/cirurgia , Encéfalo/fisiologia , Convulsões
4.
Indian J Pathol Microbiol ; 66(1): 180-183, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36656237

RESUMO

Atrophic kidney like lesion (AKLL) is a recently described benign entity with only 14 cases reported so far. Genitourinary Pathology Society proposed inclusion of AKLL as a provisional entity in 2021. It mimics thyroid follicular-like carcinoma of kidney as it has a follicular architecture. We report a case of an 18-year-old female with detection of renal mass, while the patient was being investigated for abdominal pain. Mediastinal nodes were also enlarged with detection of necrotizing granulomas on biopsy. Histology revealed a tumor enveloped by a thick capsule with smooth muscle fibers, varying sized follicles, interspersed atrophic tubules, and calcifications. Immunohistochemically, the "cystic follicles" show WT1 +/PAX8 -/CK7-phenotype, while atrophic tubules present between "cystic follicles" harbor WT1 -/PAX8 +/CK7 + phenotype. Morphological diagnosis and differential diagnosis will be discussed.


Assuntos
Adenocarcinoma Folicular , Carcinoma , Neoplasias Renais , Neoplasias da Glândula Tireoide , Adolescente , Feminino , Humanos , Adenocarcinoma Folicular/patologia , Rim/patologia , Neoplasias Renais/patologia , Neoplasias da Glândula Tireoide/patologia , Diagnóstico Diferencial
5.
Artigo em Inglês | MEDLINE | ID: mdl-38394404

RESUMO

ABSTRACT: Mullerian tumor arising from pleura is a rare occurrence and under-reported in medical literature. We hereby present such a case in a 47 years old female who presented with pleural effusion. Pleural biopsy revealed a papillary tumor with mild-to-moderate nuclear atypia. Immunohistochemistry profile with positivity for WT1, Pax8, ER, and PR together with negative mesothelial markers and ruling out primary in female genitalia led us to a diagnosis of primary pleural serous carcinoma of mullerian origin. The patient received paclitaxel and carboplatin chemotherapy and is disease-free till now after 2 years of follow-up.

6.
Indian J Pathol Microbiol ; 65(2): 433-436, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35435388

RESUMO

Ewing sarcoma is a rare aggressive malignant round cell tumor, primarily presenting in bone and soft tissues. This study presents two cases of this tumor in unusual locations, one in right colon which presented with intussusception and other in ovary which presented clinically as carcinoma ovary. Both the cases showed histomorphology of primitive round cell tumor with characteristic immunohistochemical profile and was confirmed on molecular analysis. We aim to highlight the importance of considering Ewing sarcoma in the differential diagnoses in these locations as they have dismal prognosis with no standard treatment modality.


Assuntos
Tumores Neuroectodérmicos Primitivos Periféricos , Sarcoma de Ewing , Colo/patologia , Feminino , Humanos , Tumores Neuroectodérmicos Primitivos Periféricos/patologia , Ovário/patologia , Prognóstico , Sarcoma de Ewing/diagnóstico , Sarcoma de Ewing/patologia
7.
J Neuroendocrinol ; 34(1): e13075, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34905237

RESUMO

Thyroid disease is known to affect brain metabolism and cognitive function, although the recovery of thyroid-induced brain functional changes after treatment remains unclear. We aimed to investigate the alteration in brain functional connectivity and its correlation with neuropsychological variables in hyperthyroid patients before and after anti-thyroid treatment using a resting-state functional magnetic resonance imaging (rsfMRI) technique. This is a follow-up rsfMRI study of previous work that showed impaired brain functional connectivity in hyperthyroid patients compared to healthy controls. We included rsfMRI and neuropsychological data from 21 hyperthyroid patients out of an original cohort of 28 patients, before and after anti-thyroid treatment for 30 weeks. Functional connectivity analysis and neuropsychological scores were compared using paired t tests in patients at baseline and at follow-up. Patients showed an improvement in some of the memory (p < .05) and executive, visuospatial and motor (p < .001) functions after treatment, and also showed increased functional connectivity in the regions of the right fronto-parietal network, left fronto-parietal network, and default mode network (DMN) (p < .05). At follow-up, the functional connectivity of the right fronto-parietal network showed a significantly positive correlation with the recognition of objects memory score. The overall findings suggest that anti-thyroid treatment with carbimazole improves the functional connectivity within some of the resting state networks in the hyperthyroid patients, whereas the remaining networks still show impairment.


Assuntos
Antitireóideos/uso terapêutico , Encéfalo/efeitos dos fármacos , Hipertireoidismo/tratamento farmacológico , Vias Neurais/efeitos dos fármacos , Adulto , Encéfalo/citologia , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Carbimazol/uso terapêutico , Cognição/efeitos dos fármacos , Estudos de Coortes , Função Executiva/efeitos dos fármacos , Feminino , Humanos , Hipertireoidismo/diagnóstico , Hipertireoidismo/fisiopatologia , Hipertireoidismo/psicologia , Índia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Vias Neurais/diagnóstico por imagem , Testes Neuropsicológicos
8.
Neuroimage Clin ; 32: 102861, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34688143

RESUMO

An epileptogenic focus in the dominant temporal lobe can result in the reorganization of language systems in order to compensate for compromised functions. We studied the compensatory reorganization of language in the setting of left temporal lobe epilepsy (TLE), taking into account the interaction of language (L) with key non-language (NL) networks such as dorsal attention (DAN), fronto-parietal (FPN) and cingulo-opercular (COpN), with these systems providing cognitive resources helpful for successful language performance. We applied tools from dynamic network neuroscience to functional MRI data collected from 23 TLE patients and 23 matched healthy controls during the resting state (RS) and a sentence completion (SC) task to capture how the functional architecture of a language network dynamically changes and interacts with NL systems in these two contexts. We provided evidence that the brain areas in which core language functions reside dynamically interact with non-language functional networks to carry out linguistic functions. We demonstrated that abnormal integrations between the language and DAN existed in TLE, and were present both in tonic as well as phasic states. This integration was considered to reflect the entrainment of visual attention systems to the systems dedicated to lexical semantic processing. Our data made clear that the level of baseline integrations between the language subsystems and certain NL systems (e.g., DAN, FPN) had a crucial influence on the general level of task integrations between L/NL systems, with this a normative finding not unique to epilepsy. We also revealed that a broad set of task L/NL integrations in TLE are predictive of language competency, indicating that these integrations are compensatory for patients with lower overall language skills. We concluded that RS establishes the broad set of L/NL integrations available and primed for use during task, but that the actual use of those interactions in the setting of TLE depended on the level of language skill. We believe our analyses are the first to capture the potential compensatory role played by dynamic network reconfigurations between multiple brain systems during performance of a complex language task, in addition to testing for characteristics in both the phasic/task and tonic/resting state that are necessary to achieve language competency in the setting of temporal lobe pathology. Our analyses highlighted the intra- versus inter-system communications that form the basis of unique language processing in TLE, pointing to the dynamic reconfigurations that provided the broad multi-system support needed to maintain language skill and competency.


Assuntos
Epilepsia do Lobo Temporal , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Epilepsia do Lobo Temporal/diagnóstico por imagem , Lateralidade Funcional , Humanos , Idioma , Imageamento por Ressonância Magnética
9.
Brain Commun ; 3(2): fcab025, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34222865

RESUMO

Temporal lobe epilepsy is associated with impairment in episodic memory. A substantial subgroup, however, is able to maintain adequate memory despite temporal lobe pathology. Missing from prior work in cognitive reorganization is a direct comparison of temporal lobe epilepsy patients with intact status with those who are memory impaired. Little is known about the regional activations, functional connectivities and/or network reconfigurations that implement changes in primary computations or support functions that drive adaptive plasticity and compensated memory. We utilized task functional MRI on 54 unilateral temporal lobe epilepsy patients and 24 matched healthy controls during the performance of a paired-associate memory task to address three questions: (i) which regions implement paired-associate memory in temporal lobe epilepsy, and do they vary as a function of good versus poor performance, (ii) is there unique functional connectivity present during memory encoding that accounts for intact status by preservation of primary memory computations or the supportive computations that allow for intact memory responses and (iii) what features during memory encoding are most distinctive: is it the magnitude and location of regional activations, or the presence of enhanced functional connections to key structures such as the hippocampus? The study revealed non-dominant hemisphere regions (right posterior temporal regions) involving both increased regional activity and increased modulatory communication with the hippocampi as most important to intact memory in left temporal lobe epilepsy compared to impaired status. The profile involved areas that are neither contralateral homologues to left hemisphere memory areas, nor regions traditionally considered computationally primary for episodic memory. None of these areas of increased activation or functional connectivity were associated with advantaged memory in healthy controls. Our emphasis on different performance levels yielded insight into two forms of cognitive reorganization: computational primacy, where left temporal lobe epilepsy showed little change relative to healthy controls, and computational support where intact left temporal lobe epilepsy patients showed adaptive abnormalities. The analyses isolated the unique regional activations and mediating functional connectivity that implements truly compensatory reorganization in left temporal lobe epilepsy. The results provided a new perspective on memory deficits by making clear that they arise not just from the knockout of a functional hub, but from the failure to instantiate a complex set of reorganization responses. Such responses provided the computational support to ensure successful memory. We demonstrated that by keeping track of performance levels, we can increase understanding of adaptive brain responses and neuroplasticity in epilepsy.

10.
Pathol Res Pract ; 217: 153290, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33307344

RESUMO

BACKGROUND: Hepatocellular carcinoma (HCC) is characterized by marked phenotypic and molecular heterogeneity. Clinico-morphologic phenotypes and associations are important surrogate markers of molecular aberrations; therefore have immense relevance for targeted therapy. There is paucity of published literature on critical analysis of HCC heterogeneity and morphological alliance. AIMS: To assess the heterogeneity and dominance of histomorphological features, and to explore clinicopathological associations in HCC. METHODS: Retrospective cross-sectional study of 217 HCC tissue specimens was performed for the assessment of prevalence of major histological patterns, cytological features, and clinicopathological correlation. RESULTS: Homogeneous architecture with a single dominant histological pattern was a rarity. Single pattern constituting ≥50 % of the tumour was found in less than 1/5th of the cases. Macrotrabecular HCC represented 9.2 % of cases. The simultaneous presence of 2-3 patterns or atypical variants and/ or cytological characteristics was recorded in 25 % and 30 % respectively. Significant clinicopathological associations: Pseudoglandular with microtrabecular pattern-cholestasis, showed better differentiation and early-stage; macrotrabecular pattern frequently occurred with pleomorphic giant cells, higher tumour stage, higher AFP levels; solid pattern often showed clear cells. Noticeable mutual exclusions were MD bodies with microtrabecular and pseudoglandular patterns; Compact pattern with neutrophilic clusters and cholestasis. Larger tumours were significantly more heterogeneous; however, heterogeneity did not correlate with outcome CONCLUSIONS: HCC displays immense heterogeneity with an amalgamation of different histomorphological patterns and features; nevertheless, there are certain reproducible associations and omissions. Tumor biopsies agree fairly well with large specimens. Characterization of phenotypic heterogeneity, dominance, associations, and exclusions in individual patients provides vital information.


Assuntos
Variação Biológica da População , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Adulto , Idoso , Biópsia , Carcinoma Hepatocelular/cirurgia , Estudos Transversais , Feminino , Humanos , Neoplasias Hepáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Fenótipo , Estudos Retrospectivos
11.
Asian J Neurosurg ; 15(4): 899-907, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33708660

RESUMO

INTRODUCTION: We aimed to analyze the difficulties and complications experienced while as a beginner in endoscopic transnasal transsphenoidal approach for pituitary adenomas. MATERIALS AND METHODS: We retrospectively analyzed 83 cases done from June 2016 to August 2019. Navigation-guided endoscopic transnasal transsphenoidal approach was used in all the cases. RESULTS: Gross total tumor removal was achieved in 55 (66.26%) patients. We found that gross total resection rate was inversely proportional to Knosp grading, and the extent of resection was found to have a statistically significant correlation with grade of tumor (P < 0.05). Surgery-related complications were present in 33 of our patients. Nasal complications occurred in six patients: three epistaxis (3.6%) and two hyposmia (2.4%) and one case of septal hematoma (1.2%). Postoperative cerebrospinal fluid leak occurred in six (7.2%) cases, two (2.4%) cases had sinusitis, while two (2.4%) cases had meningitis. There was a very rare case of subarachnoid hemorrhage and one case had sellar hematoma. Endocrinologic complications occurred in 15 (18.07%) patients: anterior pituitary deficiency in five (6.02%) patients, transient diabetes insipidus (DI) in nine (10.84%) patients, and permanent DI in one (1.2%) patient. There was no vascular injury or mortality noted in our study. CONCLUSION: Endoscopic approach is an effective modality for pituitary surgery; with patience, learning lessons from your own mistakes and by adopting right technique, learning curve can be flattened significantly.

12.
Asian J Neurosurg ; 15(4): 1024-1026, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33708682

RESUMO

Myoepithelial tumor (MET) of bone is an unusual tumor of uncertain differentiation and histogenesis. Although its presence in various bones has been reported sparsely, the presentation in clivus as primary myoepithelial carcinoma (MEC) has never been reported. They resemble their salivary gland counterparts morphologically and immunohistochemically, but harbor distinct molecular phenotype. At present, moderate nuclear atypia is the acceptable criteria to differentiate MEC from myoepithelioma. Because of their rarity, wide histopathological spectrum, and intraosseous location, MET of bone is easily confused with a variety of primary bone and cartilaginous tumors. Application of immunohistochemistry and, if required, molecular testing are required for making a correct diagnosis. In this article, we describe an extremely rare case of a primary MEC arising from the clivus, which owing to unusual location and immunohistochemical profile was diagnostically challenging.

13.
J Neuroendocrinol ; 31(2): e12683, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30600576

RESUMO

Thyroid hormones epigenetically play an important role in the regularisation of neural networks and in neural differentiation during brain development. The present study aimed to explore the intra and inter network resting state functional connectivity changes underlying the neurobehavioural symptoms in thyrotoxicosis. To understand the pathophysiological changes, we investigated the correlation between functional connectivity and clinical and behavioural measures. Twenty-eight freshly diagnosed thyrotoxicosis patients suffering with symptoms such as palpitation, loss of weight, trembling and heat intolerance from days to weeks and 28 healthy controls were recruited for the study. Thyrotoxicosis patients showed significantly decreased functional connectivity in sensorimotor network, fronto-temporal network, default mode network, right fronto-parietal network, left fronto-parietal network and salience network. Inter network functional connectivity was significantly reduced between the basal ganglia network and sensorimotor network and increased between the salience network and fronto-temporal network in thyrotoxicosis. Cognitive functions such as visual retention, recognition of objects, mental balance and performance on neuropsychological tests (ie, the Bender Gestalt test, Nahar-Benson test and Mini Mental State Examination) also showed significant decline in thyrotoxicosis patients. The altered intrinsic resting state functional connectivity might underlie these cognitive deficits. The increased functional connectivity between the salience network and fronto-temporal network suggests the recruitment of additional neuronal circuitry needed to compensate for the neuropathology in the primary neural network in thyrotoxicosis.


Assuntos
Encéfalo/fisiopatologia , Tireotoxicose/fisiopatologia , Tireotoxicose/psicologia , Adulto , Mapeamento Encefálico , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Vias Neurais/fisiopatologia , Testes Neuropsicológicos
14.
Psychiatry Res Neuroimaging ; 283: 45-54, 2019 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-30530256

RESUMO

Trait anxiety is particularly a prone phenotype for the development of anxiety disorders and depression. Studying the neural underpinnings of trait anxiety can further inform our understanding of the etiology of these disorders. To investigate the structural correlates of trait anxiety, high resolution structural images were acquired from 76 right-handed healthy participants and gray matter volumes were extracted from a priori regions of interest (ROIs) that were earlier implicated in anxiety like behaviour (i.e., hippocampus, amygdala, anterior cingulate cortex, thalamus, hypothalamus and prefrontal (dorsolateral, rostrolateral, ventrolateral) cortex. In a partial correlation analysis (with age, gender, and Beck Depression Inventory (BDI) scores as covariates of no interest), trait anxiety was found to be negatively correlated with the gray matter volume of hypothalamus bilaterally and positively correlated with the gray matter volume of left thalamus. In a hierarchical multiple regression analysis, grey matter volume of hypothalamus and left thalamus were found to be the significant predictors of trait anxiety. Our findings thus suggest that a smaller gray matter volume in the hypothalamus and an increase in the gray matter volume of left thalamus is related to a disposition to high anxiety personality trait.


Assuntos
Transtornos de Ansiedade/diagnóstico por imagem , Transtornos de Ansiedade/psicologia , Substância Cinzenta/diagnóstico por imagem , Hipotálamo/diagnóstico por imagem , Individualidade , Personalidade , Adulto , Tonsila do Cerebelo/diagnóstico por imagem , Feminino , Humanos , Masculino , Adulto Jovem
15.
Case Rep Hematol ; 2018: 6452843, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30524762

RESUMO

Acute monoblastic leukemia (AMoL) is a rare hematopoietic neoplasm, and simultaneous occurrence of acute monoblastic leukemia with chronic lymphocytic leukemia is very rare and only a few cases have been reported in the literature. We here report a rare case of dual hematological malignancy in an 85-year-old male. The peripheral blood and bone marrow examination revealed dual population of atypical cells, comprising large cells with opened-up chromatin having monocytic appearance and small mature-appearing lymphocytes. Flowcytometric immunophenotyping confirmed the monocytic lineage of cells, whereas small lymphocytes showed the immunophenotype consistent with chronic lymphocytic leukemia (CLL). The final diagnosis was made as acute monoblastic leukemia with associated CLL. This is a rare case scenario, and this highlights the importance of careful morphological examination and flowcytometric immunophenotyping in the exact characterization of hematopoietic malignancies.

16.
J Biosci ; 43(5): 877-886, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30541948

RESUMO

Worries preoccupy the working memory capacity in anxious individuals, thereby affecting their performance during tasks that require efficient attention regulation. According to the attentional control theory (ACT), trait anxiety affects the processing efficiency, i.e. the effort required for task performance, more than the accuracy of task performance. We investigated the relation between trait anxiety and neural response for a reasoning task in healthy subjects. Functional magnetic resonance imaging (fMRI) was carried out on 22 healthy participants and blood oxygenation level dependent (BOLD) contrast estimates were extracted from a priori regions of interest (ROIs) that were earlier implicated in reasoning (i.e., bilaterally caudate head, globus pallidus, thalamus, prefrontal cortex [[ostral, dorsal and ventral regions]] inferior parietal lobule and middle occipital gyrus). Controlling for the effects of age, gender, state anxiety and depressive symptoms, for equivalent levels of task performance, trait anxiety of the participants was found to be associated with an increase in task related BOLD activation in right globus pallidus, left thalamus and left middle occipital gyrus. Our results suggest a reduced processing efficiency for reasoning in high trait anxiety subjects and provides important brain-behaviour relationships with respect to sub-clinical anxiety.


Assuntos
Ansiedade/fisiopatologia , Cognição/fisiologia , Depressão/fisiopatologia , Memória de Curto Prazo/fisiologia , Ansiedade/diagnóstico por imagem , Ansiedade/psicologia , Mapeamento Encefálico , Núcleo Caudado/diagnóstico por imagem , Núcleo Caudado/fisiopatologia , Depressão/diagnóstico por imagem , Depressão/psicologia , Feminino , Globo Pálido/diagnóstico por imagem , Globo Pálido/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Lobo Occipital/diagnóstico por imagem , Lobo Occipital/fisiopatologia , Lobo Parietal/diagnóstico por imagem , Lobo Parietal/fisiopatologia , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/fisiopatologia , Análise e Desempenho de Tarefas , Tálamo/diagnóstico por imagem , Tálamo/fisiopatologia , Adulto Jovem
17.
J Neuroendocrinol ; 2018 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-29504670

RESUMO

Subclinical hypothyroidism (SCH) is characterized by mild elevation of thyroid stimulating hormone (TSH) (range 5-10 µIU/ml) and normal free triiodothyronine (FT3) and free thyroxine (FT4). The cognitive function impairment is well known in thyroid disorders such as hypothyroidism and hyperthyroidism, but little is known about deficits in brain functions in SCH subjects. Also, whether hormone-replacement treatment is necessary or not in SCH subjects is still debatable. In order to have an insight into the cognition of SCH subjects, intrinsic and extrinsic functional connectivity (FC) of the resting state networks (RSNs) was studied. For resting state data analysis we used an unbiased, data-driven approach based on Independent Component Analysis (ICA) and dual-regression that can emphasize widespread changes in FC without restricting to a set of predefined seeds. 28 SCH subjects and 28 matched healthy controls (HC) participated in the study. RSN analysis showed significantly decreased intrinsic FC in somato-motor network (SMN) and right fronto-parietal attention network (RAN) and increased intrinsic FC in default mode network (DMN) in SCH subjects as compared to control subjects. The reduced intrinsic FC in the SMN and RAN suggests neuro-cognitive alterations in SCH subjects in the corresponding functions which were also evident from the deficit in the neuropsychological performance of the SCH subjects on behavioural tests such as digit span, delayed recall, visual retention, recognition, Bender Gestalt and Mini-Mental State Examination (MMSE). We also found a significant reduction in extrinsic network FC between DMN and RAN; SMN and posterior default mode network (PDMN); and increased extrinsic FC between SMN and anterior default mode network (ADMN) in SCH subjects as compared to controls. An altered extrinsic FC in SCH suggests functional reorganization in response to neurological disruption. The partial correlation analysis between intrinsic and extrinsic RSNs FC and neuropsychological performances as well as clinical indices give interesting insights into brain-behavior relationship in SCH subjects. This article is protected by copyright. All rights reserved.

18.
J Biosci ; 40(5): 909-19, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26648036

RESUMO

It is not clearly known as to why some people identify camouflaged objects with ease compared with others. The literature suggests that Field-Independent individuals detect camouflaged object better than their Field-Dependent counterparts, without having evidence at the neural activation level. A paradigm was designed to obtain neural correlates of camouflage detection, with real-life photographs, using functional magnetic resonance imaging. Twenty-three healthy human subjects were stratified as Field-Independent (FI) and Field-Dependent (FD), with Witkin's Embedded Figure Test. FIs performed better than FDs (marginal significance; p=0.054) during camouflage detection task. fMRI revealed differential activation pattern between FI and FD subjects for this task. One sample T-test showed greater activation in terms of cluster size in FDs, whereas FIs showed additional areas for the same task. On direct comparison of the two groups, FI subjects showed additional activation in parts of primary visual cortex, thalamus, cerebellum, inferior and middle frontal gyrus. Conversely, FDs showed greater activation in inferior frontal gyrus, precentral gyrus, putamen, caudate nucleus and superior parietal lobule as compared to FIs. The results give preliminary evidence to the differential neural activation underlying the variances in cognitive styles of the two groups.


Assuntos
Imageamento por Ressonância Magnética , Percepção Visual/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Experimentação Humana não Terapêutica , Lobo Parietal/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Córtex Visual , Adulto Jovem
19.
Alcohol ; 49(7): 639-46, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26537482

RESUMO

Long-term heavy alcohol consumption has traditionally been associated with impaired cognitive abilities, such as deficits in abstract reasoning, problem solving, verbal fluency, memory, attention, and visuospatial processing. The present study aimed at exploring these neuropsychological deficits in alcohol-use disorders (AUD) in an Indian population using the Postgraduate Institute Battery of Brain Dysfunction (PGIBBD) and their possible correlation with alterations in T2 relaxation times (T2-RT), using whole-brain voxel-based relaxometry (VBR) and conventional region of interest (ROI) approach. Multi-echo T2 mapping sequence was performed on 25 subjects with AUD and 25 healthy controls matched for age, education, and socioeconomic status. Whole-brain T2-RT measurements were conducted using VBR and conventional ROI approach. The study was carried out on a 3T whole-body MR scanner. Post processing for VBR and ROI analysis was performed using SPM 8 software and vendor-provided software, respectively. A PGIBBD test battery was conducted on all subjects to assess their cognitive abilities, and the results were reported as raw scores. VBR and ROI results revealed that AUD subjects showed prolonged T2-RTs in cerebellum bilaterally, parahippocampal gyrus bilaterally, right anterior cingulate cortex, left superior temporal gyrus, left middle frontal gyrus, and left calcarine gyrus. A significant correlation was also observed between the neuropsychological test raw scores and alterations in T2-RT in AUD subjects. Our results are consistent with previous studies suggesting tissue disruption or gliosis or demyelination as a possible reason for prolonged T2-RTs. This damage to brain tissue, which is evident as prolonged T2-RT, could possibly be associated with impaired cognitive abilities noticeable in AUD subjects.


Assuntos
Transtornos Relacionados ao Uso de Álcool/patologia , Transtornos Relacionados ao Uso de Álcool/psicologia , Alcoolismo/patologia , Alcoolismo/psicologia , Transtornos Cognitivos/patologia , Transtornos Cognitivos/psicologia , Adulto , Encéfalo/patologia , Mapeamento Encefálico , Doenças Desmielinizantes/patologia , Doenças Desmielinizantes/psicologia , Feminino , Gliose/patologia , Gliose/psicologia , Humanos , Processamento de Imagem Assistida por Computador , Índia , Testes de Inteligência , Imageamento por Ressonância Magnética , Masculino , Memória/fisiologia , Pessoa de Meia-Idade , Testes Neuropsicológicos , Adulto Jovem
20.
Psychiatry Res ; 234(1): 25-34, 2015 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-26385540

RESUMO

Trait anxiety, a personality dimension, has been characterized by functional consequences such as increased distractibility, attentional bias in favor of threat-related information and hyper-responsive amygdala. However, literature on the association between resting state brain functional connectivity, as studied using resting state functional magnetic resonance imaging (rs-fMRI), and reported anxiety levels in the sub-clinical population is limited. In the present study, we employed rs-fMRI to investigate the possible alterations in the functional integrity of Resting State Networks (RSNs) associated with trait anxiety of the healthy subjects (15 high anxious and 14 low anxious). The rs-fMRI data was analyzed using independent component analysis and a dual regression approach that was applied on 12 RSNs that were identified using FSL. High anxious subjects showed significantly reduced functional connectivity in regions of the default mode network (posterior cingulate gyrus, middle and superior temporal gyrus, planum polare, supramarginal gyrus, temporal pole, angular gyrus and lateral occipital gyrus) which has been suggested to be involved in episodic memory, theory of mind, self-evaluation, and introspection, and perceptual systems including medial visual network, auditory network and another network involving temporal, parieto-occipital and frontal regions. Reduction in resting state connectivity in regions of the perceptual networks might underlie the perceptual, attentional and working memory deficits associated with trait anxiety. To our knowledge, this is the first study to relate trait anxiety to resting state connectivity using independent component analysis.


Assuntos
Ansiedade/fisiopatologia , Encéfalo/fisiopatologia , Rede Nervosa/fisiopatologia , Personalidade/fisiologia , Adulto , Atenção/fisiologia , Mapeamento Encefálico/métodos , Autoavaliação Diagnóstica , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
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