Preliminary comparative study of cortical thickness in HIV-infected patients with and without working memory deficit.

PURPOSE: Changes in cerebral cortical regions occur in HIV-infected patients, even in those with mild neurocognitive disorders. Working memory / attention is one of the most affected cognitive domain in these patients, worsening their quality of life. Our objective was to assess whether cortical thickness differs between HIV-infected patients with and without working memory deficit. METHODS: Forty-one adult HIV-infected patients with and without working memory deficit were imaged on a 1.5 T scanner. Working memory deficit was classified by composite Z scores for performance on the Digits and Letter-Number Sequencing subtests of the Wechsler Adult Intelligence Scale (third edition; WAIS-III). Cortical thickness was determined using FreeSurfer software. Differences in mean cortical thickness between groups, corrected for multiple comparisons using Monte-Carlo simulation, were examined using the query design estimate contrast tool of the FreeSurfer software. RESULTS: Greater cortical thickness in left pars opercularis of the inferior frontal gyrus, and rostral and caudal portions of the left middle frontal gyrus (cluster 1; p = .004), and left superior frontal gyrus (cluster 2; p = .004) was observed in HIV-infected patients with working memory deficit compared with those without such deficit. Negative correlations were found between WAIS-III-based Z scores and cortical thickness in the two clusters (cluster 1: ρ = -0.59; cluster 2: ρ = -0.47). CONCLUSION: HIV-infected patients with working memory deficit have regions of greater thickness in the left frontal cortices compared with those without such deficit, which may reflect increased synaptic contacts and/or an inflammatory response related to the damage caused by HIV infection.

Anterior to Midposterior Corpus Callosum Subregions Are Volumetrically Reduced in Male Alcoholics but Only the Anterior Segment Is Associated to Alcohol Use.

Alcohol consumption seems to affect corpus callosum morphometry irrespectively of an alcohol use disorder (AUD) diagnosis. The present study examined the relationship between corpus callosum (CC) subregion volumes and alcohol use patterns in AUD and non-AUD subjects. Twenty-two male AUD patients and 23 healthy matched non-AUD subjects were recruited from March 2016 to July 2017. Volumetric data were acquired through Magnetic Resonance and analyzed by the FreeSurfer software. AUD subjects were in abstinence for 45.1 days ± 36.8 (SD), consumed higher amounts of alcohol and presented higher AUDIT scores than controls (p < 0.0001). A multivariate analysis corrected by age and tobacco use indicated that AUD patients presented smaller CC volumes compared to non-AUD subjects (p < 0.01), except for the posterior subregion. A multiple regression analysis corrected by age and tobacco use including CC volumes from all subjects and the amount of daily alcohol ingestion as variables indicated that anterior CC volume was negatively (p < 0.001) associated to alcohol consumption. This study demonstrated that CC subregions were smaller in AUD subjects, as expected, and that the volume of the anterior segment was inversely associated to increasing daily amounts of alcohol, indicating greater frontal region vulnerability to harmful alcohol effects.

Superparamagnetic iron oxide nanoparticles as a tool to track mouse neural stem cells in vivo.

Cell transplantation offers a promising approach in many neurological disorders. Neural stem (NS) cells are potential candidates for cell therapy. The ability to track the grafted cells in the host tissue will refine this therapy. Superparamagnetic iron oxide nanoparticles (SPION) have been suggested as a feasible method, but there is no consensus about its safety. Here we investigated the feasibility of label NS cells with SPION and track by MRI after transplantation into mouse striatum with SPION cells and its therapeutic effects by grafting the cells into mouse striatum. We demonstrated that SPION-labeled NS cells display normal patterns of cellular processes including proliferation, migration, differentiation and neurosphere formation. Transmission electron microscopy reveals SPION in the cytoplasm of the cells, which was confirmed by microanalysis. Neurons and astrocytes generated from SPION-labeled NS cells were able to carry nanoparticles after 7 days under differentiation. SPION-labeled NS cells transplanted into striatum of mice were detected by magnetic resonance imaging (MRI) and microscopy 51 days later. In agreement with others reports, we demonstrated that NS cells are able to incorporate SPION in vitro without altering the stemness, and can survive and be tracked by MRI after they have been grafted into mice striatum.

Congenital Zika syndrome and neuroimaging findings: what do we know so far? / Síndrome congênita pelo vírus Zika e achados de neuroimagem: o que sabemos até o momento?

Abstract Although infection with the Zika virus was first recognized in 1942, it received little attention until 2007, when a true pandemic spread throughout Africa, Asia, and the Americas. Since then, numerous forms of central nervous system involvement have been described, mainly malformations related to congenital infection. Although the neuroimaging findings in congenital Zika syndrome are not pathognomonic, many are quite suggestive of the diagnosis, and radiologists should be prepared to interpret such findings accordingly. The objective of this article is to review the computed tomography and magnetic resonance imaging findings in congenital Zika syndrome.

Resumo A infecção pelo vírus Zika, apesar de conhecida desde 1942, apresentou destaque somente a partir de 2007, quando uma verdadeira pandemia se espalhou pela África, Ásia e Américas. Durante este período, numerosas formas de acometimento do sistema nervoso central têm sido descritas, principalmente as malformações relacionadas a infecção congênita. Apesar de os achados de neuroimagem na síndrome congênita pelo vírus Zika não serem patognomônicos, muitos são bastante sugestivos, devendo o radiologista estar preparado para saber interpretar e sugerir o diagnóstico. O objetivo deste artigo é revisar os achados de tomografia computadorizada e ressonância magnética da síndrome congênita pelo vírus Zika.

Applicability of three-dimensional imaging techniques in fetal medicine / Aplicabilidade da tecnologia tridimensional na medicina fetal

Abstract Objective: To generate physical models of fetuses from images obtained with three-dimensional ultrasound (3D-US), magnetic resonance imaging (MRI), and, occasionally, computed tomography (CT), in order to guide additive manufacturing technology. Materials and Methods: We used 3D-US images of 31 pregnant women, including 5 who were carrying twins. If abnormalities were detected by 3D-US, both MRI and in some cases CT scans were then immediately performed. The images were then exported to a workstation in DICOM format. A single observer performed slice-by-slice manual segmentation using a digital high resolution screen. Virtual 3D models were obtained from software that converts medical images into numerical models. Those models were then generated in physical form through the use of additive manufacturing techniques. Results: Physical models based upon 3D-US, MRI, and CT images were successfully generated. The postnatal appearance of either the aborted fetus or the neonate closely resembled the physical models, particularly in cases of malformations. Conclusion: The combined use of 3D-US, MRI, and CT could help improve our understanding of fetal anatomy. These three screening modalities can be used for educational purposes and as tools to enable parents to visualize their unborn baby. The images can be segmented and then applied, separately or jointly, in order to construct virtual and physical 3D models.

Resumo Objetivo: Gerar modelos físicos de fetos utilizando imagens obtidas por ultrassonografia tridimensional (US3D), ressonância magnética (RM) e, em alguns casos, tomografia computadorizada (TC), para orientar a técnica de adição de camadas. Materiais e Métodos: Foram usadas imagens obtidas de 31 gestantes, incluindo 5 casos de gestação gemelar. Os exames foram realizados usando US3D, RM e em alguns casos TC, e os arquivos foram exportados para uma estação de trabalho em formato DICOM. Um único observador realizou o processo de segmentação manual usando tela de alta resolução. Um software que converte imagens médicas em modelos numéricos foi utilizado para construir modelos virtuais 3D, que foram fisicamente materializados. Resultados: Os modelos virtuais e físicos baseados na US3D, RM e TC realizados separadamente ou em conjunto foram concluídos com sucesso. A aparência pós-natal do feto abortado ou do recém-nascido se assemelhou muito com os modelos físicos, particularmente nos casos de malformações. Conclusão: O uso da US3D, RM e TC pode ajudar para melhor compreensão das características físicas do feto. Essas técnicas podem ser usadas com fins didáticos para auxiliar na abordagem multidisciplinar e na melhor compreensão dos pais. As imagens podem ser segmentadas e aplicadas separadamente ou combinadas para construir modelos virtuais 3D e físicos.

Working memory and left medial temporal cortical thickness / Memória de trabalho e espessura cortical temporal medial esquerda

ABSTRACT Objective To perform a pilot study to investigate the association between working memory and cortical thickness in a sample of attention deficit/hyperactivity disorder (ADHD) children. Methods Seventeen children aged 7-10 years diagnosed with ADHD and 16 healthy children underwent a magnetic resonance scan for cortical thickness measurements. Data was correlated with working memory performance using the Backwards Digit Span subtest of the Wechsler Intelligence Scale for Children. Results Working memory impairment, evidenced by lower scores on the Backwards Digit Span, was observed in patients with ADHD compared to healthy controls. There was a direct correlation between working memory and cortical thickness of the left medial temporal lobe (Spearman’s correlation coefficient: 0.499; p < 0.005). Conclusions Our data suggests, for the first time, a correlation between working memory, evaluated by the Backwards Digit Span, and left medial temporal cortical thickness.

RESUMO Objetivo Realizar estudo piloto para investigar a associação entre memória de trabalho e espessura cortical em crianças com transtorno de défict de atenção e hiperatividade (TDAH). Métodos Dezessete crianças com TDAH, entre 7 e 10 anos, e dezesseis crianças saudáveis foram submetidas a ressonância magnética para aferição de espessura cortical. Os dados foram correlacionados com desempenho da memória de trabalho usando a ordem inversa do subteste Dígitos da Escala de Inteligência Wechsler para Crianças. Resultados Prejuízos na memória de trabalho, evidenciado pela menor pontuação na ordem inversa do subteste Dígitos, foram observados em pacientes com TDAH, em comparação com crianças saudáveis. Observou-se correlação direta entre memória de trabalho e espessura do lobo temporal médio à esquerda (coeficiente de correlação de Spearman: 0,499; p < 0,005). Conclusões Nossos dados sugerem, pela primeira vez, uma correlação entre memória de trabalho, avaliada através da pontuação na ordem inversa do subteste Dígitos, e espessura do córtex temporal medial à esquerda.

Neurocysticercosis, familial cerebral cavernomas and intracranial calcifications: differential diagnosis for adequate management.

Neurocysticercosis (NCC) is an endemic disease and important public health problem in some areas of the World and epilepsy is the most common neurological manifestation. Multiple intracranial lesions, commonly calcified, are seen on cranial computed tomography (CT) in the chronic phase of the disease and considered one of the diagnostic criteria of the diagnosis. Magnetic resonance imaging (MRI) is the test that better depicts the different stages of the intracranial cysts but does not show clearly calcified lesions. Cerebral cavernous malformations (CCM), also known as cerebral cavernomas, are frequent vascular malformations of the brain, better demonstrated by MRI and have also epilepsy as the main form of clinical presentation. When occurring in the familial form, cerebral cavernomas typically present with multiple lesions throughout the brain and, very often, with foci of calcifications in the lesions when submitted to the CT imaging. In the countries, and geographic areas, where NCC is established as an endemic health problem and neuroimaging screening is done by CT scan, it will be important to consider the differential diagnosis between the two diseases due to the differences in adequate management.

Neurocysticercosis, familial cerebral cavernomas and intracranial calcifications: differential diagnosis for adequate management / Neurocisticose, cavernoma cerebral familiar e calcificações intracranianas: diagnóstico diferencial e acompanhamento adequado

ABSTRACT Neurocysticercosis (NCC) is an endemic disease and important public health problem in some areas of the World and epilepsy is the most common neurological manifestation. Multiple intracranial lesions, commonly calcified, are seen on cranial computed tomography (CT) in the chronic phase of the disease and considered one of the diagnostic criteria of the diagnosis. Magnetic resonance imaging (MRI) is the test that better depicts the different stages of the intracranial cysts but does not show clearly calcified lesions. Cerebral cavernous malformations (CCM), also known as cerebral cavernomas, are frequent vascular malformations of the brain, better demonstrated by MRI and have also epilepsy as the main form of clinical presentation. When occurring in the familial form, cerebral cavernomas typically present with multiple lesions throughout the brain and, very often, with foci of calcifications in the lesions when submitted to the CT imaging. In the countries, and geographic areas, where NCC is established as an endemic health problem and neuroimaging screening is done by CT scan, it will be important to consider the differential diagnosis between the two diseases due to the differences in adequate management.

RESUMO A neurocisticercose (NCC) é um importante problema endêmico de saúde pública em algumas áreas do mundo, sendo epilepsia sua manifestação clínica mais comum. Múltiplas lesões intracranianas, geralmente com calcificações visualizadas em tomografia computorizada de crânio, são interpretadas como um dos critérios diagnósticos na fase crônica da doença. A ressonância magnética é o melhor teste de imagem para identificar a doença em diferentes estágios de sua forma cística mas apresenta limitações para demonstrar lesões calcificadas. Malformações cavernosas cerebrais, ou cavernomas, são malformações vasculares comuns ao sistema nervoso e epilepsia é também a sua forma mais frequente de apresentação. Na sua forma familiar cavernomas apresentam-se tipicamente com múltiplas lesões encefálicas e, frequentemente, com focos de calcificações na TC. Em alguns países, e determinadas regiões geográficas, onde neurocisticercose é endêmica, a neuroimagem mais usada para diagnóstico é a TC de crânio. Nesse contexto torna-se importante estabelecer bases para o diagnóstico diferencial entre as duas doenças, devido às diferentes formas de acompanhamento e tratamento adequado.

Quantitative Susceptibility Mapping Indicates a Disturbed Brain Iron Homeostasis in Neuromyelitis Optica - A Pilot Study.

Dysregulation of brain iron homeostasis is a hallmark of many neurodegenerative diseases and can be associated with oxidative stress. The objective of this study was to investigate brain iron in patients with Neuromyelitis Optica (NMO) using quantitative susceptibility mapping (QSM), a quantitative iron-sensitive MRI technique. 12 clinically confirmed NMO patients (6 female and 6 male; age 35.4y±14.2y) and 12 age- and sex-matched healthy controls (7 female and 5 male; age 33.9±11.3y) underwent MRI of the brain at 3 Tesla. Quantitative maps of the effective transverse relaxation rate (R2*) and magnetic susceptibility were calculated and a blinded ROI-based group comparison analysis was performed. Normality of the data and differences between patients and controls were tested by Kolmogorov-Smirnov and t-test, respectively. Correlation with age was studied using Spearman's rank correlation and an ANCOVA-like analysis. Magnetic susceptibility values were decreased in the red nucleus (p<0.01; d>0.95; between -15 and -22 ppb depending on reference region) with a trend toward increasing differences with age. R2* revealed significantly decreased relaxation in the optic radiations of five of the 12 patients (p<0.0001; -3.136±0.567 s(-1)). Decreased relaxation in the optic radiation is indicative for demyelination, which is in line with previous findings. Decreased magnetic susceptibility in the red nucleus is indicative for a lower brain iron concentration, a chemical redistribution of iron into less magnetic forms, or both. Further investigations are necessary to elucidate the pathological cause or consequence of this finding.