Regional brain atrophy is related to social cognition impairment in multiple sclerosis / La atrofia cerebral regional se relaciona con el deterioro de la cognición social en sclerosis múltiple

ABSTRACT Background: Multiple sclerosis exhibits specific neuropathological phenomena driving to both global and regional brain atrophy. At the clinical level, the disease is related to functional decline in cognitive domains as the working memory, processing speed, and verbal fluency. However, the compromise of social-cognitive abilities has concentrated some interest in recent years despite the available evidence suggesting the risk of disorganization in social life. Recent studies have used the MiniSEA test to assess the compromise of social cognition and have found relevant relationships with memory and executive functions, as well as with the level of global and regional brain atrophy. Objective: The present article aimed to identify structural changes related to socio-cognitive performance in a sample of patients with relapsing-remitting multiple sclerosis. Methods: 68 relapsing-remitting multiple sclerosis Chilean patients and 50 healthy control subjects underwent MRI scans and neuropsychological evaluation including social-cognition tasks. Total brain, white matter, and gray matter volumes were estimated. Also, voxel-based morphometry was applied to evaluate regional structural changes. Results: Patients exhibited lower scores in all neuropsychological tests. Social cognition exhibited a significant decrease in this group mostly related to the declining social perception. Normalized brain volume and white matter volume were significantly decreased when compared to healthy subjects. The regional brain atrophy analysis showed that changes in the insular cortex and medial frontal cortices are significantly related to the variability of social-cognitive performance among patients. Conclusions: In the present study, social cognition was only correlated with the deterioration of verbal fluency, despite the fact that previous studies have reported its link with memory and executive functions. The identification of specific structural correlates supports the comprehension of this phenomenon as an independent source of cognitive disability in these patients.

RESUMEN Antecedentes: La esclerosis múltiple presenta fenómenos neuropatológicos específicos que conducen a la atrofia cerebral global y regional. A nivel clínico, la enfermedad está relacionada con el deterioro funcional de los dominios cognitivos como la memoria de trabajo, la velocidad de procesamiento y la fluidez verbal. Sin embargo, el compromiso de las habilidades socio-cognitivas ha concentrado cierto interés en los últimos años debido a la evidencia disponible que sugiere el riesgo de desorganización en la vida social. Estudios recientes han utilizado la prueba MiniSEA para evaluar el compromiso de la cognición social y han encontrado relaciones relevantes con la memoria y funciones ejecutiva, así como con el nivel de atrofia cerebral global y regional. Objetivo: El presente artículo tiene como objetivo identificar cambios estructurales relacionados con el rendimiento sociocognitivo en una muestra de pacientes con esclerosis múltiple recurrente-remitente. Métodos: 68 pacientes Chilenos con esclerosis múltiple recurrente-remitente y 50 sujetos de control sanos se sometieron a resonancias magnéticas y evaluación neuropsicológica, incluidas las tareas de cognición social. Se estimaron los volúmenes cerebrales totales, de materia blanca y materia gris. Además, se aplicó la morfometría basada en vóxel para evaluar los cambios estructurales regionales. Resultados: Los pacientes muestran puntuaciones más bajas en todas las pruebas neuropsicológicas. La cognición social exhibe una disminución significativa en este grupo principalmente relacionada con la disminución de la percepción social. El volumen normalizado del cerebro y el volumen de la materia blanca disminuyeron significativamente en comparación con los sujetos sanos. El análisis regional de atrofia cerebral mostró que los cambios en la corteza insular y la corteza frontal medial están significativamente relacionados con la variabilidad del rendimiento sociocognitivo entre los pacientes. Conclusiones: En el presente estudio, la cognición social sólo se correlacionó con el deterioro de la fluencia verbal, a pesar de que estudios previos han reportado su vinculación con la memoria y funciones ejecutivas. La identificación de correlatos estructurales específicos apoya la comprensión de este fenómeno como una fuente independiente de discapacidad cognitiva en estos pacientes.

Marcello Malpighi: the nervous system under a microscope / Marcello Malpighi: o sistema nervoso sob um microscópio

ABSTRACT The longstanding study of gross anatomy experienced a considerable improvement with the advent of the microscope in the early 17th century. The representative personality of this new era certainly was Marcello Malpighi, seen as "founder of microscopic anatomy". He studied, with a rudimentary compound microscope, numerous tissues and organs of several classes of animals, as well as plants. He described, for the first time, the microscopic structure of the nervous system, identifying in the gray matter of its various levels minute elements he took as "glands". It should be reminded that the concept of "cell" (and "nerve cell") was unknown at his time. Many researchers followed, performing microscopic studies, but without better results, and Malpighi's view was maintained until the beginning of the 19th century, when new histological processing and staining techniques appeared, as well as improved microscopes.

RESUMO O estudo de longa data da anatomia macroscópica experimentou um incremento considerável com o advento do microscópio no início do século 17. A personalidade representativa dessa nova era foi, certamente, Marcello Malpighi, considerado "fundador da anatomia microscópica". Ele estudou, com um microscópio composto rudimentar, numerosos tecidos e órgãos de diversas classes de animais, assim como plantas. Descreveu, pela primeira vez, a estrutura microscópica do sistema nervoso, identificando na substância cinzenta dos vários níveis elementos de minúsculas dimensões, que denominou "glândulas". Deve-se lembrar que o conceito de "célula" (e de "célula nervosa") era desconhecido naquele tempo. Muitos pesquisadores seguiram realizando estudos microscópicos, mas sem resultados melhores, e o entendimento de Malpighi foi mantido até o início do século 19, quando apareceram técnicas histológicas novas de processamento e de coloração, assim como microscópios mais aprimorados.

Differences in total brain volume between sexes in a cognitively unimpaired elderly population

OBJECTIVES: Although a large number of studies have shown brain volumetric differences between men and women, only a few investigations have analyzed brain tissue volumes in representative samples of the general elderly population. We investigated differences in gray matter (GM) volumes, white matter (WM) volumes, and intracranial volumes (ICVs) between the sexes in individuals older than 66 years using structural magnetic resonance imaging (MRI). METHODS: Using FreeSurfer version 5.3, we obtained the ICVs and GM and WM volumes from the MRI datasets of 84 men and 92 women. To correct for interindividual variations in ICV, GM and WM volumes were adjusted with a method using the residuals of a least-square-derived linear regression between raw volumes and ICVs. We then performed an analysis of covariance comparing men and women, including age and years of schooling as confounding factors. RESULTS: Women had a lower socioeconomic status overall and fewer years of schooling than men. The comparison of unadjusted brain volumes showed larger GM and WM volumes in men. After the ICV correction, the adjusted volumes of GM and WM were larger in women. CONCLUSION: After the ICV correction and taking into account differences in socioeconomic status and years of schooling, our results confirm previous findings of proportionally larger GM in women, as well as larger WM volumes. These results in an elderly population indicate that brain volumetric differences between sexes persist throughout the aging process. Additional studies combining MRI and other biomarkers to identify the hormonal and molecular bases influencing such differences are warranted.

Voxel-wise meta-analysis of structural changes in gray matter of Parkinsons disease patients with mild cognitive impairment

Evidence from previous voxel-based morphometry (VBM) studies indicates that widespread brain regions are involved in Parkinson's disease with mild cognitive impairment (PD-MCI). However, the spatial localization reported for gray matter (GM) abnormalities is heterogeneous. The aim of the present study was to quantitatively integrate studies on GM abnormalities observed in PD-MCI in order to determine whether a pattern exists. Eligible whole-brain VBM studies were identified by a systematic search of articles in PubMed and EMBASE databases spanning from 1995 to January 1, 2019. A meta-analysis was performed to investigate regional GM abnormalities in PD-MCI. The anisotropic effect size version of seed-based d mapping (AES-SDM) meta-analysis was conducted to explore the GMV differences of PD-MCI compared with PD patients with normal cognitive function (PD-NC). A total of 12 studies comprising 243 PD-MCI patients and 326 PD-NC were included in the meta-analysis. PD-MCI patients showed a robust GM decrease in the left insula and left superior temporal gyrus. Moreover, meta-regression analysis demonstrated that age, PD duration and stage, and Unified Parkinson's Disease Rating Scale III and Mini-Mental State Examination scores might be partly correlated with the GM abnormalities observed in PD-MCI patients. The convergent findings of this quantitative meta-analysis revealed a characteristic neuroanatomical pattern in PD-MCI. The findings provide some evidence that MCI in PD may result in the breakdown of the insula and temporal gyrus, which may serve as specific regions of interest for further investigations.

Gray matter atrophy in parkinsons disease and the parkinsonian variant of multiple system atrophy: a combined roi- and voxel-based morphometric study

OBJECTIVES: Parkinson's disease (PD) and the parkinsonian variant of multiple system atrophy (MSA-P) are distinct neurodegenerative disorders that share similar clinical features of parkinsonism. The morphological alterations of these diseases have yet to be understood. The purpose of this study was to evaluate gray matter atrophy in PD and MSA-P using regions of interest (ROI)-based measurements and voxel-based morphometry (VBM). METHODS: We studied 41 patients with PD, 20 patients with MSA-P, and 39 controls matched for age, sex, and handedness using an improved T1-weighted sequence that eased gray matter segmentation. The gray matter volumes were measured using ROI and VBM. RESULTS: ROI volumetric measurements showed significantly reduced bilateral putamen volumes in MSA-P patients compared with those in PD patients and controls (p<0.05), and the volumes of the bilateral caudate nucleus were significantly reduced in both MSA-P and PD patients compared with those in the controls (p<0.05). VBM analysis revealed multifocal cortical and subcortical atrophy in both MSA-P and PD patients, and the volumes of the cerebellum and temporal lobes were remarkably reduced in MSA-P patients compared with the volumes in PD patients (p<0.05). CONCLUSIONS: Both PD and MSA-P are associated with gray matter atrophy, which mainly involves the bilateral putamen, caudate nucleus, cerebellum, and temporal lobes. ROI and VBM can be used to identify these morphological alterations, and VBM is more sensitive and repeatable and less time-consuming, which may have potential diagnostic value.

Major depressive disorder with childhood trauma:Clinical characteristics, biological mechanism, and therapeutic implications / 中南大学学报(医学版)

Major depressive disorder (MDD) is a main type of mood disorder, characterized by significant and lasting depressed mood. Until now, the pathogenesis of MDD is not clear, but it is certain that biological, psychological, and social factors are involved. Childhood trauma is considered to be an important factor in the development of this disease. Previous studies have found that nearly half of the patients with MDD have experienced childhood trauma, and different types of childhood trauma, gender, and age show different effects on this disease. In addition, the clinical characteristics of MDD patients with childhood trauma are also different, which often have more severe depressive symptoms, higher risk of suicide, and more severe cognitive impairment. The response to antidepressants is also worse. In terms of biological mechanisms and marker characteristics, the serotonin transporter gene and the FKBP prolyl isomerase 5 have been shown to play an important role in MDD and childhood trauma. Moreover, some brain imaging and biomarkers showed specific features, such as changes in gray matter in the dorsal lateral prefrontal cortex, and abnormal changes in hypothalamic-pituitary-adrenal axis function.

Reproducibility analysis of quantitative susceptibility mapping of cerebral subcortical nuclei in healthy adults / 南方医科大学学报

OBJECTIVE@#To investigate the intra- and inter-scanner reproducibility of quantitative susceptibility mapping (QSM) of cerebral subcortical nuclei in healthy adults.@*METHODS@#QSM was performed in 21 healthy adults on two different 3.0T MR scanners, and the region of interest (ROI) method was used to measure the magnetic susceptibility value of the left subcortical nuclei (the head of the caudate, putamen, globus pallidus, thalamus, substantia nigra and red nucleus). The intraclass correlation coefficient (ICC) and Bland-Altman method were used to evaluate the inter-scanner and intra-scanner reliability.@*RESULTS@#The ICCs of the susceptibility value ranged from 0.90 to 0.99 for all the subcortical gray nuclei except for the head of the caudate nucleus measured on the same MR scanner by the same observer. Bland-Altman analysis revealed that the points with susceptibility differences for all the subcortical gray nuclei except for substantia nigra located in the 95% CI of limits of agreement for the same MR scanner. The ICCs of the susceptibility value for the inter-scanner was 0.49 (0.08-0.75) for the head of the caudate nuleus, 0.80 (0.57-0.91) for the putamen, 0.77 (0.51-0.90) for the globus pallidus, 0.78 (0.54-0.91) for the thalamus, 0.80 (0.56-0.91) for the substantia nigra and 0.93 (0.83-0.97) for the red nucleus. The points with susceptibility difference (95.2%, 20/21) located in the 95% CI of limits of agreement for the putamen and the thalamus measured on two different MR scanners.@*CONCLUSIONS@#The intra-scanner reproducibility of QSM of the subcortical gray nuclei is superior to the inter-scanner reproducibility in healthy adults.

Morphological relationship between the superficial cortical and deep grey matter structures in adult human brains: a cadaveric study / Relación morfológica entre las estructuras superficiales de la sustancia gris cortical y profunda en los cerebros humanos adultos: un estudio en cadáveres

While various neurodegenerative diseases affect cortical mass differently, finding an optimal and accurate method for measuring the thickness and surface area of cerebral cortex remains a challenging problem due to highly convoluted surface of the cortex. We therefore investigated cortical thickness in a sample of cadaveric specimens at the Discipline of Clinical Anatomy, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, South Africa to provide some clue as to possible variations in the parameters. Following ethical approval, 60 brain samples were uniformly sectioned (5 mm thickness) and eight slices taken from each brain across regions of interest (ROI) prepared and stained by Mulligan's technique. Thickness was measured at selected angles (0º, 45º, 90º, 135º and 180º) for both right and left cerebral hemispheres. Mulligan's stain produced good cortical differentiation and clear images that enabled manual delineation of structures. Cortical thickness ranged from 3 to 5 millimeters across the ROI. Interestingly, there was rightward hemispheric asymmetry of cortical thickness of selective slices at suggested angles which is related to structurally and functionally important brain regions. Moreover, there was no significant correlation between the surface area of superficial cortex and the deep nuclei at the same level. The superficial cortex and deep nuclei are manifested independently in normal aging, neuropsychiatric or developmental disorders. Providing accurate morphometric evaluation of cortical thickness and area based on gross staining of the brain slices could provide qualitative data that may support the study of human cerebral cortex even in disease conditions.

Si bien varias enfermedades neurodegenerativas afectan a la masa cortical de manera diferente, encontrar un método óptimo y preciso para medir el grosor y el área de la superficie de la corteza cerebral sigue siendo un problema difícil debido a la superficie altamente enrevesada de la corteza. Por lo tanto, investigamos el grosor cortical en una muestra de cadáveres del Departamento de Anatomía Clínica de la Facultad de Medicina Nelson R. Mandela de la Universidad de KwaZulu-Natal, Sudáfrica, para proporcionar alguna pista sobre posibles variaciones en dichos parámetros. Después de la aprobación ética, 60 muestras de cerebro se seccionaron uniformemente (5 mm de grosor) y se tomaron ocho cortes de cada cerebro en regiones de interés (ROI) preparadas y teñidas con la técnica de Mulligan. El espesor se midió en los ángulos seleccionados (0º, 45º, 90º, 135º y 180º) para los hemisferios cerebrales derecho e izquierdo. La tinción de Mulligan produjo una buena diferenciación cortical e imágenes claras que permitieron la delineación manual de las estructuras. El grosor cortical osciló entre 3 y 5 milímetros a través del ROI. Curiosamente, hubo una asimetría hemisférica hacia la derecha del grosor cortical de los cortes en ángulos sugeridos que se relacionan con regiones cerebrales estructural y funcionalmente importantes. Además, no hubo una correlación significativa entre el área de la superficial de la corteza superficial y los núcleos profundos en el mismo nivel. La corteza superficial y los núcleos profundos se manifiestan de manera independiente en el envejecimiento normal, en los trastornos neuropsiquiátricos o del desarrollo. Realizar una evaluación morfométrica precisa del grosorcortical y el área basada en la tinción macroscópica de los cortes del cerebro, podría proporcionar datos cualitativos que puedan respaldar el estudio de la corteza cerebral humana incluso en condiciones de enfermedad.

Paraplegia after celiac plexus neurolysis in a patient with pancreatic cancer: A case report and literature review

A 65-year-old male patient underwent C-arm fluoroscopy-guided bilateral celiac plexus neurolysis to relieve peritoneal seeding-related pain associated with pancreatic cancer. Following confirmation of spreading, and no intravascular injection of contrast media, 7.5 ml of 0.25% chirocaine was injected in each side. The pain subsided after the block, with no motor or sensory deficits. Subsequently, celiac plexus neurolysis with 99.8% alcohol was performed using a posterolateral approach under fluoroscopic guidance. The patient was instructed to maintain a prone position for 2 hours while the procedure was performed. Approximately 4 hours later, the patient experienced paralysis of both lower extremities and hypoesthesia. Emergent magnetic resonance imaging of the thoracic and lumbar spine revealed gray matter signal change in the cord and conus medullaris at the T10-L1 level, and decreased perfusion at the T11-T12 vertebral bodies, suggesting spinal cord infarction. The patient remained paraplegic until his death 24 days later.

Utility of white matter to gray matter signal intensity ratio in comatose patients treated by targeted temperature management after cardiac arrest: a preliminary study

OBJECTIVE: This study examined the efficacy of the white matter (WM) to gray matter (GM) signal intensity ratio (SIR) in predicting the clinical prognosis of cardiac arrest patients. METHODS: Thirty-one patients who were resuscitated from cardiac arrest and underwent brain magnetic resonance imaging (MRI) were investigated retrospectively. Thirty one subjects with normal brain MRI findings served as the controls. The signal intensities (SI) were measured on T2-weighted image (T2WI). The circular regions of measurement (2–10 mm²) were placed over the regions of interest, and the average signals in GM and WM were recorded in the caudate nucleus (CN), putamen, anterior limb of the internal capsule, corpus callosum (CC), and in the cortex and WM of the frontal lobe. Cerebral performance category (CPC) 1–2 were classified as a good prognosis, and CPC 3–5 were classified as a poor prognosis. RESULTS: Most combinations of the SIR of WM to GM and most SIs of GM, except the frontal cortex, were significantly different between the two groups. On the other hand, the SI of WM was insignificant between both groups. In receiver operating characteristic (ROC) curve analysis, the SIR of the CC to CN had an area under the ROC curve (AUROC) of 1.00 for a cut-off value of 1.59 (sensitivity, 100%; specificity, 100%), the SIR of the CC to putamen had also an AUROC of 1.00 for a cut-off value of 1.43 (sensitivity, 100%; specificity, 100%). CONCLUSION: The SIR of WM to GM measured on a T2WI is related to the neurological outcome after a cardiac arrest.

Evaluation of Tumor Blood Flow Using Alternate Ascending/Descending Directional Navigation in Primary Brain Tumors: A Comparison Study with Dynamic Susceptibility Contrast Magnetic Resonance Imaging

OBJECTIVE: Alternate ascending/descending directional navigation (ALADDIN) is a novel arterial spin labeling technique that does not require a separate spin preparation pulse. We sought to compare the normalized cerebral blood flow (nCBF) values obtained by ALADDIN and dynamic susceptibility contrast (DSC) perfusion magnetic resonance imaging (MRI) in patients with primary brain tumors. MATERIALS AND METHODS: Sixteen patients with primary brain tumors underwent MRI scans including contrast-enhanced T1-weighted imaging, DSC perfusion MRI, and ALADDIN. The nCBF values of normal gray matter (GM) and tumor areas were measured by both DSC perfusion MRI and ALADDIN, which were compared by the Wilcoxon signed rank test. Subgroup analyses according to pathology were performed with the Wilcoxon signed rank test. RESULTS: Higher mean nCBF values of GM regions in the bilateral frontal lobe, temporal lobe, and caudate were detected by ALADDIN than by DSC perfusion MRI (p <0.05). In terms of the mean or median nCBF values and the mean of the top 10% nCBF values from tumors, DSC perfusion MRI and ALADDIN did not statistically significantly differ either overall or in each tumor group. CONCLUSION: ALADDIN tended to detect higher nCBF values in normal GM, as well as higher perfusion portions of primary brain tumors, than did DSC perfusion MRI. We believe that the high perfusion signal on ALADDIN can be beneficial in lesion detection and characterization.

Analysis of Apparent Diffusion Coefficients of the Brain in Healthy Controls: A Comparison Study between Single-Shot Echo-Planar Imaging and Read-out-Segmented Echo-Planar Imaging

OBJECTIVE: To compare apparent diffusion coefficients (ADCs) of brain segments by using two diffusion-weighted imaging acquisition modes, single-shot echo-planar imaging (ss-EPI) and read-out-segmented echo-planar imaging (rs-EPI), and to assess their correlation and agreement in healthy controls. MATERIALS AND METHODS: T2-weighted (T2W) images, rs-EPI, and ss-EPI of 30 healthy subjects were acquired using a 3T magnetic resonance scanner. The T2W images were co-registered to the rs-EPI and ss-EPI, which were then segmented into the gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) to generate masking templates. ADC maps of rs-EPI and ss-EPI were also segmented into the GM, WM, and CSF by using the generated templates. ADCs of rs-EPI and ss-EPI were compared using Student's t tests and correlated using Pearson's correlation coefficients. Bland-Altman plots were used to assess the agreement between acquisitions.

Quantitative Proteomic Analysis Reveals Impaired Axonal Guidance Signaling in Human Postmortem Brain Tissues of Chronic Traumatic Encephalopathy

Chronic traumatic encephalopathy (CTE) is a distinct neurodegenerative disease that associated with repetitive head trauma. CTE is neuropathologically defined by the perivascular accumulation of abnormally phosphorylated tau protein in the depths of the sulci in the cerebral cortices. In advanced CTE, hyperphosphorylated tau protein deposits are found in widespread regions of brain, however the mechanisms of the progressive neurodegeneration in CTE are not fully understood. In order to identify which proteomic signatures are associated with CTE, we prepared RIPA-soluble fractions and performed quantitative proteomic analysis of postmortem brain tissue from individuals neuropathologically diagnosed with CTE. We found that axonal guidance signaling pathwayrelated proteins were most significantly decreased in CTE. Immunohistochemistry and Western blot analysis showed that axonal signaling pathway-related proteins were down regulated in neurons and oligodendrocytes and neuron-specific cytoskeletal proteins such as TUBB3 and CFL1 were reduced in the neuropils and cell body in CTE. Moreover, oligodendrocyte-specific proteins such as MAG and TUBB4 were decreased in the neuropils in both gray matter and white matter in CTE, which correlated with the degree of axonal injury and degeneration. Our findings indicate that deregulation of axonal guidance proteins in neurons and oligodendrocytes is associated with the neuropathology in CTE. Together, altered axonal guidance proteins may be potential pathological markers for CTE.

Long-Term Grey Matter Changes in First Episode Psychosis: A Systematic Review

OBJECTIVE: To determine possible progressive changes of the grey matter at the first stages of the schizophrenia spectrum disorders, and to determine what regions are involved in these changes. METHODS: We searched the literature concerning studies on longitudinal changes in grey matter in first-episode psychosis using magnetic resonance imaging, especially studies with an interval between scans of more than a year. Only articles published before 2018 were searched. We selected 19 magnetic resonance imaging longitudinal studies that used different neuroimaging analysis techniques to study changes in cerebral grey matter in a group of patients with a first episode of psychosis. RESULTS: Patients with first episode of psychosis showed a decrease over time in cortical grey matter compared with a group of control subjects in frontal, temporal (specifically in superior regions), parietal, and subcortical regions. In addition to the above, studies indicate that patients showed a grey matter decrease in cerebellum and lateral ventricles volume. CONCLUSION: The results suggest a decrease in grey matter in the years after the first episode of psychosis. Furthermore, the results of the studies showed consistency, regardless of the methods used in their analyses, as well as the time intervals between image collections.

Gray Matter Microstructural Abnormalities and Working Memory Deficits in Individuals with Schizophrenia

OBJECTIVE: Working memory impairments serve as prognostic factors for patients with schizophrenia. Working memory deficits are mainly associated with gray matter (GM) thickness and volume. We investigated the association between GM diffusivity and working memory in controls and individuals with schizophrenia. METHODS: T1 and diffusion tensor images of the brain, working memory task (letter number sequencing) scores, and the demographic data of 90 individuals with schizophrenia and 97 controls were collected from the SchizConnect database. T1 images were parcellated into the 68 GM Regions of Interest (ROI). Axial Diffusivity (AD), Fractional Anisotropy (FA), Radial Diffusivity (RD), and Trace (TR) were calculated for each of the ROIs. RESULTS: Compared to the controls, schizophrenia group showed significantly increased AD, RD, and TR in specific regions on the frontal, temporal, and anterior cingulate area. Moreover, working memory was negatively correlated with AD, RD, and TR in the lateral orbitofrontal, superior temporal, inferior temporal, and rostral anterior cingulate area on left hemisphere in the individuals with schizophrenia. CONCLUSION: These results demonstrated GM microstructural abnormalities in the frontal, temporal, and anterior cingulate regions of individuals with schizophrenia. Furthermore, these regional GM microstructural abnormalities suggest a neuropathological basis for the working memory deficits observed clinically in individuals with schizophrenia.

White matter volume is decreased in bipolar disorder at early and late stages / O volume da substância branca está reduzido tanto nos estágios iniciais quanto nos estágios avançados do transtorno bipolar

Abstract Introduction: Bipolar disorder (BD) is a debilitating mood condition that affects approximately 1.3% of people worldwide, although some studies report up to 3.9% lifetime prevalence and 4-6% in adults when broad diagnostic criteria are applied. Objective: To compare differences in total white matter (WM), corpus callosum (CC) and total gray matter (GM) volumes in patients with type I BD at early and late stages compared with controls. Methods: Fifty-five subjects were enrolled in this study protocol. The double case-control design included 14 patients with BD at early stage; 15 patients at late stage; and their respective matched controls (14 and 12 subjects). Results: CC and total WM volumes were significantly smaller in patients with BD at early and late stages vs. controls. There was no difference for total GM volume in the early stage group, but in patients at late stage total GM volume was significantly smaller than in controls. The total GM volume reduction in patients at late stage is in agreement with the neuroprogression theory of BD. The reduction of WM volumes in total WM and in the CC at early and late stages supports the possibility that an early demyelination process could occur underlying the clinical manifestation of BD. Conclusion: Our findings may direct to the investigation of WM abnormalities in populations at high risk to develop BD, perhaps as early biomarkers before the overt syndrome.

Resumo Introdução: O transtorno do humor bipolar (THB) é uma condição debilitante que afeta aproximadamente 1,3% das pessoas em todo o mundo, embora alguns estudos relatem uma prevalência acumulada de até 3,9% e de 4-6% em adultos quando os critérios diagnósticos mais abrangentes são aplicados. Objetivo: Comparar as diferenças nos volumes totais de substância branca (SB), corpo caloso (CC) e volume total de substância cinzenta (SC) em pacientes com THB tipo I em estágios iniciais e tardios em comparação com controles. Métodos: Cinquenta e cinco sujeitos foram incluídos neste protocolo de estudo. O desenho de caso com duplo controle incluiu 14 pacientes com THB em estágio inicial; 15 pacientes com THB em fase tardia; e seus respectivos controles correspondentes (14 e 12 sujeitos). Resultados: Os volumes do CC e total de SB foram significativamente menores nos pacientes com THB nos estágios iniciais e tardios vs. controles. Não houve diferença para o volume total de SC no grupo em estágio inicial, mas em pacientes em fase tardia o volume total de SC foi significativamente menor do que nos controles. A redução do volume total de SC em pacientes em fase tardia está de acordo com a teoria da neuroprogressão do THB. A redução dos volumes de SB em SB total e no CC em fases precoces e tardias suporta a possibilidade de que um processo de desmielinização precoce poderia ocorrer subjacente à manifestação clínica de THB. Conclusão: Nossos achados podem direcionar a investigação de anormalidades da SB em populações de alto risco para o desenvolvimento de THB, talvez como biomarcadores precoces antes da síndrome aberta.

Effects of virtual reality therapy on upper limb function after stroke and the role of neuroimaging as a predictor of a better response / Efeitos da terapia de realidade virtual na função do membro superior após AVC e o papel da neuroimagem como preditor de melhor resposta

ABSTRACT Background: Virtual reality therapy (VRT) is an interactive intervention that induces neuroplasticity. The aim was to evaluate the effects of VRT associated with conventional rehabilitation for an upper limb after stroke, and the neuroimaging predictors of a better response to VRT. Methods: Patients with stroke were selected, and clinical neurological, upper limb function, and quality of life were evaluated. Statistical analysis was performed using a linear model comparing pre- and post-VRT. Lesions were segmented in the post-stroke computed tomography. A voxel-based lesion-symptom mapping approach was used to investigate the relationship between the lesion and upper limb function. Results: Eighteen patients were studied (55.5 ± 13.9 years of age). Quality of life, functional independence, and dexterity of the upper limb showed improvement after VRT (p < 0.001). Neuroimaging analysis showed negative correlations between the internal capsule lesion and functional recovery. Conclusion: VRT showed benefits for patients with stroke, but when there was an internal capsule lesion, a worse response was observed.

RESUMO Introdução: A realidade virtual (RV) é uma intervenção interativa que induz a neuroplasticidade. O objetivo deste estudo foi avaliar os efeitos da RV associado à reabilitação convencional na função do membro superior após o AVC e as características preditores de neuroimagem de melhor resposta a esta terapia. Métodos: os pacientes com AVC foram selecionados, e as características neurológicas, a função do membro superior e a qualidade de vida foram avaliadas. A análise estatística foi realizada por meio de modelo linear geral comparando resultados pré e pós-intervenção. As lesões foram segmentadas na tomografia computadorizada após o AVC. A abordagem de mapeamento da lesão-sintoma baseada em voxel foi utilizada para avaliar a relação entre a lesão e a função do membro superior. Resultados: Foram estudados 18 pacientes (8 mulheres, 55,5 ± 13,9 anos). A qualidade de vida, independência funcional, características funcionais e destreza do membro superior apresentaram melhora após RV (p < 0,001). A análise de imagem mostrou correlações negativas principalmente entre a cápsula interna e a recuperação funcional do membro superior. Conclusão: A RV mostrou benefícios para pacientes com AVC, mas quando houve lesão da cápsula interna apresentaram pior resposta à terapia.

Magnetic Resonance Image Texture Analysis of the Periaqueductal Gray Matter in Episodic Migraine Patients without T2-Visible Lesions

OBJECTIVE: The periaqueductal gray matter (PAG), a small midbrain structure, presents dysfunction in migraine. However, the precise neurological mechanism is still not well understood. Herein, the aim of this study was to investigate the texture characteristics of altered PAG in episodic migraine (EM) patients based on high resolution brain structural magnetic resonance (MR) images. MATERIALS AND METHODS: The brain structural MR images were obtained from 18 normal controls (NC), 18 EM patients and 16 chronic migraine (CM) patients using a 3T MR system. A PAG template was created using the International Consortium Brain Mapping 152 gray matter model, and the individual PAG segment was developed by applying the deformation field from the structural image segment to the PAG template. A grey level co-occurrence matrix was used to calculate the texture parameters including the angular second moment (ASM), contrast, correlation, inverse difference moment (IDM) and entropy. RESULTS: There was a significant difference for ASM, IDM and entropy in the EM group (998.629 ± 0.162 × 10−3, 999.311 ± 0.073 × 10−3, 916.354 ± 0.947 × 10−5) compared to that found in the NC group (998.760 ± 0.110 × 10−3, 999.358 ± 0.037 × 10−3 and 841.198 ± 0.575 × 10−5) (p < 0.05). The entropy was significantly lower among the patients with CM (864.116 ± 0.571 × 10−5) than that found among patients with EM (p < 0.05). The area under the receiver operating characteristic curve was 0.776 and 0.750 for ASM and entropy in the distinction of the EM from NC groups, respectively. ASM was negatively related to disease duration (DD) and the Migraine Disability Assessment Scale (MIDAS) scores in the EM group, and entropy was positively related to DD and MIDAS in the EM group (p < 0.05). CONCLUSION: The present study identified altered MR image texture characteristics of the PAG in EM. The identified texture characteristics could be considered as imaging biomarkers for EM.

Gray Matter Volume Reductions Were Associated with TPH1 Polymorphisms in Depressive Disorder Patients with Suicidal Attempts

OBJECTIVE: Structural changes of brain areas have been reported in depressive disorder and suicidal behavior (SB), in which TPH1 also has been known as a promising candidate gene. We investigated gray matter volume (GMV) differences, TPH1 rs1800532 and rs1799913 polymorphisms previously found to be associated with depressive disorder and SB, and the relationship between the two markers. METHODS: Thirteen depressive disorder patients with suicidal attempts (SA) and twenty healthy controls were included. We examined GMV differences using a voxel-based morphometry and regions of interest analysis. Direct sequencing was used for genotyping. RESULTS: The patients showed significant GMV reduction in left cerebral region including middle frontal gyrus, inferior frontal gyrus, and anterior cingulate cortex; in right middle temporal gyrus; in left cerebellar tonsil; and in right cerebral region including precentral gyrus and postcentral gyrus (corrected p < 0.005). The right precentral and postcentral gyri GMV values of AA and CA genotypes patients were significantly decreased compared to those of CC genotype subjects (corrected p=0.040). CONCLUSION: These findings show the possibility that both GMV reductions and TPH1 rs1800532/rs1799913 A allele may be involved in the pathogenesis of depressive disorder patients with SA.

Current Radiopharmaceuticals for Positron Emission Tomography of Brain Tumors

Brain tumors represent a diverse spectrum of histology, biology, prognosis, and treatment options. Although MRI remains the gold standard for morphological tumor characterization, positron emission tomography (PET) can play a critical role in evaluating disease status. This article focuses on the use of PET with radiolabeled glucose and amino acid analogs to aid in the diagnosis of tumors and differentiate between recurrent tumors and radiation necrosis. The most widely used tracer is ¹⁸F-fluorodeoxyglucose (FDG). Although the intensity of FDG uptake is clearly associated with tumor grade, the exact role of FDG PET imaging remains debatable. Additionally, high uptake of FDG in normal grey matter limits its use in some low-grade tumors that may not be visualized. Because of their potential to overcome the limitation of FDG PET of brain tumors, 11C-methionine and ¹⁸F-3,4-dihydroxyphenylalanine (FDOPA) have been proposed. Low accumulation of amino acid tracers in normal brains allows the detection of low-grade gliomas and facilitates more precise tumor delineation. These amino acid tracers have higher sensitivity and specificity for detecting brain tumors and differentiating recurrent tumors from post-therapeutic changes. FDG and amino acid tracers may be complementary, and both may be required for assessment of an individual patient. Additional tracers for brain tumor imaging are currently under development. Combinations of different tracers might provide more in-depth information about tumor characteristics, and current limitations may thus be overcome in the near future. PET with various tracers including FDG, ¹¹C-methionine, and FDOPA has improved the management of patients with brain tumors. To evaluate the exact value of PET, however, additional prospective large sample studies are needed.