Network controllability analysis of awake and asleep conditions in the brain / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

The difference between sleep and wakefulness is critical for human health. Sleep takes up one third of our lives and remains one of the most mysterious conditions; it plays an important role in memory consolidation and health restoration. Distinct neural behaviors take place under awake and asleep conditions, according to neuroimaging studies. While disordered transitions between wakefulness and sleep accompany brain disease, further investigation of their specific characteristics is required. In this study, the difference is objectively quantified by means of network controllability. We propose a new pipeline using a public intracranial stereo-electroencephalography (stereo-EEG) dataset to unravel differences in the two conditions in terms of system neuroscience. Because intracranial stereo-EEG records neural oscillations covering large-scale cerebral areas, it offers the highest temporal resolution for recording neural behaviors. After EEG preprocessing, the EEG signals are band-passed into sub-slow (0.1‍-‍1 Hz), delta (1‍-‍4 Hz), theta (4‍-‍8 Hz), alpha (8‍-‍13 Hz), beta (13‍-‍30 Hz), and gamma (30‍-‍45 Hz) band oscillations. Then, dynamic functional connectivity is extracted from time-windowed EEG neural oscillations through phase-locking value (PLV) and non-overlapping sliding time windows. Next, average and modal network controllability are implemented on these time-varying brain networks. Based on this preliminary study, it appears that significant differences exist in the dorsolateral frontal-parietal network (FPN), salience network (SN), and default-mode network (DMN). The combination of network controllability and dynamic functional networks offers new insight for characterizing distinctions between awake and asleep stages in the brain. In other words, network controllability captures the underlying brain dynamics under both awake and asleep conditions.

A research on epilepsy source localization from scalp electroencephalograph based on patient-specific head model and multi-dipole model / 生物医学工程学杂志

Accurate source localization of the epileptogenic zone (EZ) is the primary condition of surgical removal of EZ. The traditional localization results based on three-dimensional ball model or standard head model may cause errors. This study intended to localize the EZ by using the patient-specific head model and multi-dipole algorithms using spikes during sleep. Then the current density distribution on the cortex was computed and used to construct the phase transfer entropy functional connectivity network between different brain areas to obtain the localization of EZ. The experiment result showed that our improved methods could reach the accuracy of 89.27% and the number of implanted electrodes could be reduced by (19.34 ± 7.15)%. This work can not only improve the accuracy of EZ localization, but also reduce the additional injury and potential risk caused by preoperative examination and surgical operation, and provide a more intuitive and effective reference for neurosurgeons to make surgical plans.

Localization of epileptogenic zone based on reconstruction of dynamical epileptic network and virtual resection / 生物医学工程学杂志

Drug-refractory epilepsy (DRE) may be treated by surgical intervention. Intracranial EEG has been widely used to localize the epileptogenic zone (EZ). Most studies of epileptic network focus on the features of EZ nodes, such as centrality and degrees. It is difficult to apply those features to the treatment of individual patients. In this study, we proposed a spatial neighbor expansion approach for EZ localization based on a neural computational model and epileptic network reconstruction. The virtual resection method was also used to validate the effectiveness of our approach. The electrocorticography (ECoG) data from 11 patients with DRE were analyzed in this study. Both interictal data and surgical resection regions were used. The results showed that the rate of consistency between the localized regions and the surgical resections in patients with good outcomes was higher than that in patients with poor outcomes. The average deviation distance of the localized region for patients with good outcomes and poor outcomes were 15 mm and 36 mm, respectively. Outcome prediction showed that the patients with poor outcomes could be improved when the brain regions localized by the proposed approach were treated. This study provides a quantitative analysis tool for patient-specific measures for potential surgical treatment of epilepsy.

Representations of object animacy and real-world size in the ventral visual pathway / 生理学报

How the brain perceives objects and classifies perceived objects is one of the important goals of visual cognitive neuroscience. Previous research has shown that when we see objects, the brain's ventral visual pathway recognizes and classifies them, leading to different ways of interacting with them. In this paper, we summarize the latest research progress of the ventral visual pathway related to the visual classification of objects. From the perspective of the neural representation of objects and its underlying mechanisms in the visual cortex, we summarize the current research status of the two important organizational dimensions of object animacy and real-world size, provide new insights, and point out the direction of further research.

Current contribution of diffusion tensor imaging in the evaluation of diffuse axonal injury / Contribuição atual da imagem por tensor de difusão na avaliação da lesão axonal difusa

ABSTRACT Traumatic brain injury (TBI) is the number one cause of death and morbidity among young adults. Moreover, survivors are frequently left with functional disabilities during the most productive years of their lives. One main aspect of TBI pathology is diffuse axonal injury, which is increasingly recognized due to its presence in 40% to 50% of all cases that require hospital admission. Diffuse axonal injury is defined as widespread axonal damage and is characterized by complete axotomy and secondary reactions due to overall axonopathy. These changes can be seen in neuroimaging studies as hemorrhagic focal areas and diffuse edema. However, the diffuse axonal injury findings are frequently under-recognized in conventional neuroimaging studies. In such scenarios, diffuse tensor imaging (DTI) plays an important role because it provides further information on white matter integrity that is not obtained with standard magnetic resonance imaging sequences. Extensive reviews concerning the physics of DTI and its use in the context of TBI patients have been published, but these issues are still hazy for many allied-health professionals. Herein, we aim to review the current contribution of diverse state-of-the-art DTI analytical methods to the understanding of diffuse axonal injury pathophysiology and prognosis, to serve as a quick reference for those interested in planning new studies and who are involved in the care of TBI victims. For this purpose, a comprehensive search in Pubmed was performed using the following keywords: "traumatic brain injury", "diffuse axonal injury", and "diffusion tensor imaging".

RESUMO O traumatismo cranioencefálico (TCE) é a principal causa de morbimortalidade entre adultos jovens. Aqueles que sobrevivem são frequentemente deixados com sequelas funcionais nos anos mais produtivos de suas vidas. O principal aspecto fisiopatológico do TCE é a lesão axonial difusa (LAD), cada vez mais destacada pois está presente em 40 a 50% dos casos que necessitam de internação hospitalar. LAD é definida como a injúria axonial extensa caracterizada pela axoniotomia completa assim como pelas reações secundárias a axoniopatia, que são demonstradas por métodos de neuroimagem como áreas de edema e micro-hemorragia. Entretanto, os achados da LAD são frequentemente subestimados em estudos de neuroimagem convencional. É neste contexto que imagens por tensor de difusão (DTI) ganharam ênfase, já que permitem obter informações sobre a integridade da substância branca que não eram obtidas por sequências convencionais de ressonância magnética (RM). Existem artigos extensos sobre os fundamentos físicos e as aplicações de DTI em pacientes vítimas de TCE, no entanto, estes assuntos permanecem ainda nebulosos a alguns profissionais da área de saúde. Deste modo, propomos uma revisão didática sobre a contribuição do estado da arte de diferentes métodos analíticos de DTI no entendimento do processo da fisiopatologia e prognóstico da LAD, servindo assim como uma ferramenta acessível para aqueles interessados em planejamento de novos estudos e aqueles envolvidos no tratamento de vítimas de TCE. Uma pesquisa abrangente foi realizada no Pubmed com as seguintes palavras-chave: "traumatismo cranioencefálico", "lesão axonial difusa", "imagem por tensor de difusão".

Cerebral blood flow and vasoreactivity in aging: an arterial spin labeling study

Regional cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) in young and elderly participants were assessed using pulsed arterial spin labeling (ASL) and blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) techniques in combination with inhalation of CO2. Pulsed ASL and BOLD-MRI were acquired in seventeen asymptomatic volunteers (10 young adults, age: 30±7 years; 7 elderly adults, age: 64±8 years) with no history of diabetes, hypertension, and neurological diseases. Data from one elderly participant was excluded due to the incorrigible head motion. Average baseline CBF in gray matter was significantly reduced in elderly (46±9 mL·100 g-1·min-1) compared to young adults (57±8 mL·100 g-1·min-1; P=0.02). Decreased pulsed ASL-CVR and BOLD-CVR in gray matter were also observed in elderly (2.12±1.30 and 0.13±0.06 %/mmHg, respectively) compared to young adults (3.28±1.43 and 0.28±0.11 %/mmHg, respectively; P<0.05), suggesting some degree of vascular impairment with aging. Moreover, age-related decrease in baseline CBF was observed in different brain regions (inferior, middle and superior frontal gyri; precentral and postcentral gyri; superior temporal gyrus; cingulate gyri; insula, putamen, caudate, and supramarginal gyrus). In conclusion, CBF and CVR were successfully investigated using a protocol that causes minimal or no discomfort for the participants. Age-related decreases in baseline CBF and CVR were observed in the cerebral cortex, which may be related to the vulnerability for neurological disorders in aging.

Clinical electroencephalogram (EEG) evaluation is improved by the amplitude asymmetry index / Avaliação da assimetria de amplitudes amplia o uso clínico do eletroencefalograma (EEG)

ABSTRACT Cerebral hemispheres, although similar, are neither completely symmetrical in structure nor equivalent in function. EEG asymmetry studies have been directed more to frequency than to amplitude analysis. Objective Better definition of normal amplitude asymmetry values on the classical EEG frequency bands. Results EEG amplitude asymmetry index (AAI) is physiologically low in normal adults, differences usually lesser than 7%. Conclusion Persistent or intermittent amplitude asymmetry regional differences higher than 7% may be suggestive of pathology after adequate correlation with clinical data and EEG classical visual analysis.

RESUMO Os hemisférios cerebrais não são simétricos em morfologia ou funções. Tradicionalmente, os estudos de assimetria do EEG focaram mais na análise de frequências do que na de amplitudes. Objetivo Contribuir para melhor definição dos valores normais de assimetria de amplitudes nas faixas de frequência clássicas do EEG. Resultados O índice de assimetria de amplitudes é fisiologicamente baixo em adultos, usualmente menor do que 7%. Conclusão Se adequadamente correlacionadas aos dados clínicos e à análise visual do EEG, assimetrias persistentes ou intermitentes de amplitude acima de 7% podem ser sugestivas de patologia.

Effect of prosthodontic planning on lateral occlusion scheme: a comparison between conventional and digital planning

Recently, digital wax-up is proposed as a tool to aid prosthodontic planning. However, there are no data about the effect of prosthodontic planning on lateral occlusion scheme. Objective : This study aims to evaluate the impact of conventional and digital prosthodontic planning on lateral occlusion scheme. Material and Methods : Dental models of 10 patients were collected. All models had Angle Class I occlusion and were undergoing prosthodontic treatment that would influence the lateral occlusion scheme. Each set of models had received both conventional wax-up and digital wax-up. In relation to the lateral occlusion scheme, the following variables were evaluated: the prevalence of the different lateral occlusion scheme, number of contacting teeth and percentage of each contacting tooth. Four excursive positions on the working side were included: 0.5, 1.0, 2.0 and 3.0 mm from the maximal intercuspation position. Results : The lateral occlusion scheme of the two wax-up models was subjected to alterations following excursion. There was a tendency for the prevalence of canine-guided occlusion to increase and for the prevalence of group function occlusion to decrease with increasing excursion. The number of contacting teeth was decreasing with the increasing magnitude of excursion. For the 0.5 mm and 1.0 mm positions, the two wax-ups had significantly greater contacts than the pre-treatment models, while at the 2.0 mm and 3.0 mm positions, all the models were similar. For all models, canines were the most commonly contacting teeth, followed by the teeth adjacent to them. No difference was observed between the two wax-ups in relation to the number of contacting teeth. Conclusion : Although the prosthodontic planning had influenced the pattern of the lateral occlusion scheme and contacts, there was no difference between the conventional and digital prosthodontic planning. .

Somatic and cognitive-affective depressive symptoms among patients with heart disease: differences by sex and age / Sintomas depressivos somáticos e cognitivo-afetivos entre pacientes com doença cardíaca: diferenças por sexo e idade / Síntomas depresivos somáticos y cognitivo-afectivos entre pacientes con enfermedad cardíaca: diferencias por sexo y edad

OBJECTIVE: this study investigated the association of somatic and cognitive-affective symptoms with sex and age, among patients hospitalized with heart disease. METHOD: this study was a secondary analysis of two previous observational studies totaling 531 patients with heart disease, hospitalized from 2005 to 2011 in two public hospitals in Ribeirão Preto, state of São Paulo, Brazil. Somatic and cognitive-affective symptoms were assessed using the subscales of the Beck Depression Inventory - I (BDI-I). RESULTS: of 531 participants, 62.7% were male, with a mean age 57.3 years (SD= 13.0) for males and 56.2 years (SD= 12.1) for females. Analyses of variance showed an effect of sex (p<0.001 for somatic and p=0.005 for cognitive-affective symptoms), but no effect of age. Women presented with higher mean values than men in both BDI-I subscales: 7.1 (4.5) vs. 5.4 (4.3) for somatic, and 8.3 (7.9) vs. 6.7 (7.2) for cognitive-affective symptoms. There were no differences by age for somatic (p=0.84) or cognitive-affective symptoms (p=0.84). CONCLUSION: women hospitalized with heart disease had more somatic and cognitive-affective symptoms than men. We found no association of somatic and cognitive-affective symptoms with age. Future research for these patients could reveal whether these differences according to sex continue throughout the rehabilitation process. .

OBJETIVO: investigar a associação de sintomas somáticos e cognitivo-afetivos ao sexo e à idade de pacientes hospitalizados com doença cardíaca. MÉTODO: este estudo é resultado de uma análise secundária de dois estudos observacionais anteriores, totalizando 531 pacientes com doença cardíaca, internados de 2005 a 2011, em dois hospitais públicos em Ribeirão Preto, estado de São Paulo, Brasil. Os sintomas somáticos e cognitivo-afetivos foram avaliados utilizando-se as subescalas do Inventário de Depressão de Beck - I (IDB-I). RESULTADOS: dos 531 participantes, 62,7% são do sexo masculino, com média de idade de 57,3 anos (DP= 13,0) para os homens e 56,2 anos (DP = 12,1) para as mulheres. A análise da variância mostrou um efeito relacionado ao sexo do paciente (p<0,001 para sintomas somáticos e p=0,005 para os sintomas cognitivo-afetivos), mas nenhum efeito relacionado à idade. As mulheres apresentaram maiores escores do que os homens em ambas subescalas IDB-I: 7,1 (4,5) e 5,4 (4,3) para os sintomas somáticos, e 8,3 (7,9) e 6,7 (7,2) para os sintomas cognitivo-afetivos, respectivamente. Não houve diferenças referentes à idade para sintomas somáticos (p=0,84) ou sintomas cognitivo-afetivos (p=0,84). CONCLUSÃO: as mulheres internadas com doença cardíaca apresentaram mais sintomas somáticos e cognitivo-afetivos do que os homens. Não houve associação dos sintomas somáticos e cognitivo-afetivos com a idade. Pesquisas futuras desses pacientes poderiam revelar se essas diferenças de acordo com o sexo permanecem durante todo o processo de reabilitação. .

OBJETIVO: este estudio investigó la asociación de síntomas somáticos y cognitivo-afectivos con el sexo y la edad en pacientes hospitalizados con enfermedad cardíaca. MÉTODO: este estudio fue un análisis secundario de dos estudios observacionales anteriores, totalizando 531 pacientes con enfermedad cardíaca, internados de 2005 a 2011, en dos hospitales públicos en Ribeirão Preto, estado de São Paulo, Brasil. Los síntomas somáticos y cognitivo-afectivos fueron evaluados utilizándose las subescalas del Inventario Beck de Depresión - I (IBD-I). RESULTADOS: de los 531 participantes, 62,7% era del sexo masculino, con promedio de edad de 57,3 años (DE= 13,0) para los hombres y 56,2 años (DE = 12,1) para el sexo femenino. El análisis de variancia mostró un efecto del sexo (p<0,001 para síntomas somáticos y p=0,005 para los síntomas cognitivo-afectivos), pero ningún efecto de la edad. Las mujeres presentaron valores medios más altos que los hombres en ambas subescalas IBD-I: 7,1 (4,5) vs. 5.4 (4.3) para los síntomas somáticos, y 8,3 (7,9) vs. 6,7 (7,2) para los síntomas cognitivo-afectivos. No fueron encontradas diferencias por edad para síntomas somáticos (p=0,84) o síntomas cognitivo-afectivos (p=0,84). CONCLUSIÓN: las mujeres internadas con enfermedad cardíaca tenían más síntomas somáticos y cognitivo-afectivos que los hombres. No fue encontrada asociación de los síntomas somáticos y cognitivo-afectivos con la edad. Investigaciones futuras de esos pacientes podrían revelar si esas diferencias por sexo continúan durante todo el proceso de rehabilitación. .

Estado nutricional de vitaminas A e D em crianças participantes de programa de suplementação alimentar / Vitamin A and D status among child participants in a food supplementation program / Concentraciones séricas de vitaminas A y D en niños del programa de distribución de leche fortificada

Foram avaliados as concentrações séricas de vitaminas A e D e os fatores associados em crianças beneficiárias de programa de distribuição de leite fortificado, sendo utilizados modelos de regressão linear múltiplos com seleção hierárquica de variáveis independentes (condição sociodemográfica, de saúde, alimentação, amamentação, consumo do leite fortificado, exposição solar, antropometria, retinol e calcidiol séricos). Foram consideradas insuficiência e deficiência de vitamina A e de vitamina D as concentrações séricas < 1,05µmol/L, 0,70µmo/L, 30ng/mL e 20ng/mL, respectivamente. Houve inadequação do consumo alimentar de vitaminas A e D. As prevalências de insuficiência e deficiência de vitamina A e de vitamina D foram 19%, 6%, 82% e 58%, respectivamente. Os fatores associados às menores concentrações séricas de vitamina A foram: amamentação materna exclusiva < 120 dias, ausência de trabalho materno combinada com menor escolaridade materna, maior número de pessoas que consomem leite fortificado no domicílio e menor vitamina D sérica. Para a vitamina D, foram: menor exposição ao sol e menor vitamina A sérica. Ações de educação nutricional são necessárias para melhorar a situação nutricional dessas crianças.

Vitamin A and D serum concentrations and risk factors for their deficiencies were investigated in children participating in a government-sponsored fortified milk program. The study used multivariate linear regression analysis with hierarchical selection of independent variables: socio-demographic conditions, children's health, food consumption, breastfeeding, fortified milk, exposure to sunlight, anthropometric measurements, and serum concentration of retinol and 25(OH)D. Vitamin A and vitamin D insufficiency and deficiency values were defined as < 1.05µmol/L, < 0.7µmol/L, < 30ng/mL, and < 20ng/mL, respectively. Vitamin A and D intake was inadequate. Prevalence rates for vitamin A and vitamin D insufficiency and deficiency were 19%, 6%, 82%, and 58%, respectively. Factors associated with low serum vitamin A were exclusive breastfeeding for less than 120 days, low maternal schooling, maternal unemployment, more consumers of fortified milk in the family, and low serum vitamin D. Factors associated with vitamin D deficiency were low exposure to sunlight and low serum vitamin A. Nutritional education is needed to improve children's nutritional status.

Se evaluaron las concentraciones séricas de vitaminas A y D y factores asociados en niños que se benefician del programa de distribución de leche fortificada. Se utilizaron múltiples modelos de regresión lineal, con una selección jerárquica de las variables independientes (estatus sociodemográfico, salud, alimentación, lactancia materna, consumo de leche fortificada, exposición al sol, medidas antropométricas, retinol y calcidiol séricos). Para la insuficiencia y deficiencia de vitamina A y vitamina D, se adoptaron concentraciones séricas < 1,05µmol/L, < 0,70µmol/L, < 30ng/mL, < 20ng/mL, respectivamente. La inadecuación del consumo de alimentos para vitamina A y vitamina D fue de un 40% y 100%, respectivamente. La prevalencia de insuficiencia y la deficiencia de vitamina A y vitamina D fue de un 19%, 6%, 82% y 58%, respectivamente. Los factores asociados más pequeños de vitamina A sérica fueron: lactancia exclusiva < 120 días, ausencia de empleo de la madre, combinada con una baja educación materna y menor vitamina D sérica. Para la vitamina D fueron: menor exposición al sol y menor vitamina A sérica. Las acciones de educación nutricional son necesarias para mejorar la situación nutricional de estos niños.

Utilização dos serviços de atendimento odontológico hospitalar sob sedação e/ou anestesia geral por pessoas com necessidades especiais no SUS-MG, Brasil / Availability of hospital dental care services under sedation or general anesthesia for individuals with special needs in the Unified Health System for the State of Minas Gerais (SUS-MG), Brazil

O presente estudo identificou as características demográficas dos indivíduos e assistenciais do tratamento odontológico sob sedação e/ou anestesia geral em ambiente hospitalar no SUS-MG. Foram avaliadas todas as Autorizações de Internações Hospitalares (AIH) para o procedimento Tratamento Odontológico para Pacientes com Necessidades Especiais, de julho de 2011 a junho de 2012. Foram mensuradas variáveis demográficas e assistenciais dos atendimentos. Foram calculadas as taxas de internações por 10.000 habitantes e a cobertura assistencial realizada no estado de Minas Gerais e em cada uma das Regiões Ampliadas de Saúde. A análise descritiva das variáveis foi feita por meio de cálculo da frequência e medidas de tendência central e variabilidade. Foram avaliadas todas as 1.063 AIH pagas no período estudado, que representaram uma taxa de 0,54 internações por 10.000 habitantes. A maioria dos indivíduos era adulta, do sexo masculino, com diagnóstico de transtornos mentais ou comportamentais e residente em 27,7% dos municípios de Minas Gerais. Os procedimentos foram realizados em 39 municípios e a cobertura assistencial foi igual a 1,58%. O estudo revelou um perfil clássico do paciente atendido. Dificuldades em se estabelecer uma rede de atenção à saúde bucal foram identificadas.

This study identified the demographic characteristics of individuals and dental treatment care under sedation/general anesthesia in a hospital environment in the Unified Health System in the State of Minas Gerais (SUS-MG). All Hospitalization Authorizations (AIHs) for Dental Treatment for Patients with Special Needs procedures were evaluated between July 2011 and June 2012. Demographic and health care variables for treatment were also assessed. Hospitalization rates per 10,000 inhabitants, and health care coverage provided in the state of Minas Gerais and in each of the Broader Health Regions were calculated. Descriptive analysis of data was carried out by calculating the central trend and variability frequency and measurements. All 1,063 AIHs paid during the study period were evaluated, which is equivalent to a rate of 0.54 hospitalizations per 10,000 individuals. The majority of the patients were adult, male, diagnosed with mental or behavioral disorders and resident in 27.7% of the municipalities in Minas Gerais. The procedures were performed in 39 municipalities and the care coverage was equal to 1.58%. The study reveals a classic demographic and clinical profile of patient attendance. Difficulties in establishing a network of dental care were identified.

Aplicación de técnicas avanzadas de neuroimágenes en rehabilitación motora / Application of advanced neuroimaging in motor rehabilitation

Introducción. La resonancia magnética funcional es una técnica no invasiva que permite el mapeo cerebral y la visualización de redes de conectividad. La hemiparesia posterior a un accidente cerebrovascular constituye un buen modelo biológico para estudiar los cambios en la conectividad cerebral. El uso de este modelo se puede expandir si se obtiene información antes y después de la rehabilitación neurológica. Objetivo. Presentar los hallazgos por neuroimágenes funcionales de un paciente con accidente cerebrovascular antes y después del tratamiento de rehabilitación neurológica. Materiales y métodos. Como parte del protocolo de rehabilitación neurológica se tomaron imágenes de resonancia antes y después del tratamiento con un equipo que operaba a 1,5 T. Se obtuvieron imágenes volumétricas potenciadas en T1, imágenes de difusión para tractografía, imágenes de resonancia funcional con el paciente en reposo y haciendo movimientos de pinza con la mano derecha. Resultados. Se obtuvieron mapas funcionales antes y después de la terapia, los cuales se presentan conjuntamente con las imágenes de conectividad estructural obtenidas mediante tractografía. Se observó que los cambios clínicos estaban acompañados de cambios en los patrones de activación obtenidos por resonancia magnética funcional. Conclusión. La versatilidad que ofrece la resonancia magnética permite conocer el estado funcional y estructural del cerebro, generando así nuevas posibilidades de diagnóstico y pronóstico en pacientes que reciben rehabilitación neurológica, con lo que se pueden cuantificar y develar ciertos procesos dinámicos de plasticidad neuronal posteriores a una lesión, que son propios del sistema nervioso central.

Introduction: Functional magnetic resonance imaging is a noninvasive technique that allows mapping and visualizing of brain connectivity networks. The hemiparesis after a stroke is a good biological model to study changes in brain connectivity. This model can be expanded if information is obtained before and after neurorehabilitation therapy. Objective: To present the functional neuroimaging findings in a patient with stroke before and after performing neurorehabilitation therapy. Materials and methods: As part of the neurorehabilitation protocol, resonance imaging was performed before and after treatment with an equipment operating at 1.5 T. Volumetric T1-weighted images, diffusion images for tractography, functional resonance images with the patient at rest and with the patient performing pincer movement with the right hand were obtained. Results: Functional maps before and after therapy were obtained, which are presented together with structural connectivity images obtained by tractography. Clinical changes can be seen accompanied by changes in activation patterns obtained by functional magnetic resonance imaging. Conclusion: The versatility of magnetic resonance imaging allows further knowledge of the structural and functional state of the brain generating new possibilities for diagnosis and prognosis in patients undergoing neurorehabilitation therapy. Neurological rehabilitation processes can be quantified and they can reveal certain postlesional neuroplasticity dynamic processes that the central nervous system possesses.

Neural Substrates of Hanja (Logogram) and Hangul (Phonogram) Character Readings by Functional Magnetic Resonance Imaging

The two basic scripts of the Korean writing system, Hanja (the logography of the traditional Korean character) and Hangul (the more newer Korean alphabet), have been used together since the 14th century. While Hanja character has its own morphemic base, Hangul being purely phonemic without morphemic base. These two, therefore, have substantially different outcomes as a language as well as different neural responses. Based on these linguistic differences between Hanja and Hangul, we have launched two studies; first was to find differences in cortical activation when it is stimulated by Hanja and Hangul reading to support the much discussed dual-route hypothesis of logographic and phonological routes in the brain by fMRI (Experiment 1). The second objective was to evaluate how Hanja and Hangul affect comprehension, therefore, recognition memory, specifically the effects of semantic transparency and morphemic clarity on memory consolidation and then related cortical activations, using functional magnetic resonance imaging (fMRI) (Experiment 2). The first fMRI experiment indicated relatively large areas of the brain are activated by Hanja reading compared to Hangul reading. The second experiment, the recognition memory study, revealed two findings, that is there is only a small difference in recognition memory for semantic transparency, while for the morphemic clarity was much larger between Hanja and Hangul. That is the morphemic clarity has significantly more effect than semantic transparency on recognition memory when studies by fMRI in correlation with behavioral study.

Effect of scanner acoustic background noise on strict resting-state fMRI

Functional MRI (fMRI) resting-state experiments are aimed at identifying brain networks that support basal brain function. Although most investigators consider a ‘resting-state' fMRI experiment with no specific external stimulation, subjects are unavoidably under heavy acoustic noise produced by the equipment. In the present study, we evaluated the influence of auditory input on the resting-state networks (RSNs). Twenty-two healthy subjects were scanned using two similar echo-planar imaging sequences in the same 3T MRI scanner: a default pulse sequence and a reduced “silent” pulse sequence. Experimental sessions consisted of two consecutive 7-min runs with noise conditions (default or silent) counterbalanced across subjects. A self-organizing group independent component analysis was applied to fMRI data in order to recognize the RSNs. The insula, left middle frontal gyrus and right precentral and left inferior parietal lobules showed significant differences in the voxel-wise comparison between RSNs depending on noise condition. In the presence of low-level noise, these areas Granger-cause oscillations in RSNs with cognitive implications (dorsal attention and entorhinal), while during high noise acquisition, these connectivities are reduced or inverted. Applying low noise MR acquisitions in research may allow the detection of subtle differences of the RSNs, with implications in experimental planning for resting-state studies, data analysis, and ergonomic factors.

Anterior Commissure - Posterior Commissure Revisited

OBJECTIVE: The anterior commissure (AC) and posterior commissure (PC) are the two distinct anatomic structures in the brain which are difficult to observe in detail with conventional MRI, such as a 1.5T MRI system. However, recent advances in ultra-high resolution MRI have enabled us to examine the AC and PC directly. The objective of the present study is to standardize the shape and size of the AC and PC using a 7.0T MRI and to propose a new brain reference line. MATERIALS AND METHODS: Thirty-four, 21 males and 13 females, healthy volunteers were enrolled in this study. After determining the center of each AC and PC, we defined the connection of these centers as the central intercommissural line (CIL). We compared the known extra- and intra-cerebral reference lines with the CIL to determine the difference in the angles. Additionally, we obtained horizontal line from flat ground line of look front human. RESULTS: The difference in angle of the CIL and the tangential intercommissural line (TIL) from the horizontal line was 8.7 +/- 5.1 (11 +/- 4.8) and 17.4 +/- 5.2 (19.8 +/- 4.8) degrees in males and females, respectively. The difference in angle between the CIL and canthomeatal line was 10.1 in both male and female, and there was no difference between both sexes. Likewise, there was no significant difference in angle between the CIL and TIL between both sexes (8.3 +/- 1.1 in male and 8.8 +/- 0.7 in female). CONCLUSION: In this study, we have used 7.0T MRI to define the AC and PC quantitatively and in a more robust manner. We have showed that the CIL is a reproducible reference line and serves as a standard for the axial images of the human brain.

Neuroimaging in specific phobia disorder: a systematic review of the literature / Neuroimagem do transtorno de fobia específica: uma revisão sistemática da literatura

OBJECTIVE: Specific phobia (SP) is characterized by irrational fear associated with avoidance of specific stimuli. In recent years, neuroimaging techniques have been used in an attempt to better understand the neurobiology of anxiety disorders. The objective of this study was to perform a systematic review of articles that used neuroimaging techniques to study SP. METHOD:A literature search was conducted through electronic databases, using the keywords: imaging, neuroimaging, PET, spectroscopy, functional magnetic resonance, structural magnetic resonance, SPECT, MRI, DTI, and tractography, combined with simple phobia and specific phobia. One-hundred fifteen articles were found, of which 38 were selected for the present review. From these, 24 used fMRI, 11 used PET, 1 used SPECT, 2 used structural MRI, and none used spectroscopy. RESULT: The search showed that studies in this area were published recently and that the neuroanatomic substrate of SP has not yet been consolidated. CONCLUSION: In spite of methodological differences among studies, results converge to a greater activation in the insula, anterior cingulate cortex, amygdala, and prefrontal and orbitofrontal cortex of patients exposed to phobia-related situations compared to controls. These findings support the hypotheses of the hyperactivation of a neuroanatomic structural network involved in SP.

A Fobia Específica (SP do inglês) é caracterizada por medos irracionais associados à evitação de estímulos específicos. Nos últimos anos, técnicas de neuroimagem vêm sendo empregadas na tentativa de melhor compreender a neurobiologia dos transtornos de ansiedade. O objetivo do presente estudo é realizar uma revisão sistemática dos artigos que utilizaram neuroimagem para estudar a SP. A busca na literatura foi realizada por intermédio de indexadores eletrônicos, utilizando-se as palavras-chave: imaging, neuroimaging, PET, spectroscopy, functional magnetic ressonance, structural magnetic ressonance, SPECT, MRI, DTI e tractography, cruzadas individualmente com os termos simple phobia e specific phobia. Foram encontrados 115 artigos, sendo 38 deles selecionados para a presente revisão. Desses, 24 usaram fMRI, 11 usaram PET, 1 usou SPECT, 2 usaram MRI estrutural e nenhum artigo de espectroscopia. Verifica-se que os estudos na área foram publicados recentemente e que, até o momento, o substrato neuroanatômico deste transtorno não está consolidado. Apesar das diferenças metodológicas entre os estudos, os resultados convergem para maior ativação na ínsula, cíngulo anterior, amídala e córtex préfrontal e orbitofrontal dos pacientes expostos a situações phobia related quando comparados aos controles. Esses achados reforçam hipóteses a respeito da hiperativação de uma determinada rede de estruturas neuroanatômicas envolvidas no transtorno de SP.