Mucopolissacaridose e fossa posterior : achados de imagem por estudo de ressonância magnética

Introdução: Mucopolissacaridose (MPS) é uma doença multissistêmica hereditária integrante do grupo das desordens de depósito lisossomais. O sistema nervoso central é frequentemente acometido em pacientes com MPS, e exame de ressonância magnética (RM) é o método de escolha para avaliação do neuroeixo. A maioria dos estudos de imagem em MPS enfatizam as anormalidades do compartimento supratentorial e da junção craniocervical, enquanto estudos abordando os achados da fossa posterior nestes pacientes são escassos. Objetivo: Descrever os achados observados na fossa posterior em estudos de RM de pacientes com MPS. Métodos: Foi conduzido estudo transversal incluindo todos os casos confirmados de MPS em um hospital universitário do sul do Brasil que realizaram estudo de RM encefálica de rotina. As imagens foram avaliadas através de consenso de dois médicos radiologistas com experiência. Foi realizada avaliação qualitativa da presença de lesão de substância branca no tronco encefálico e cerebelo, volume cerebelar, tamanho e formato da fossa posterior e alargamento dos espaços liquóricos. Alargamento dos espaços perivasculares e espessura dos pedúnculos cerebelares médios (PCM) foram mensurados quantitativamente. Teste exato de Fischer foi utilizado para avaliar a associação entre fossa posterior em J invertido, macrocerebelo e alargamento dos espaços liquóricos. Resultados: 47 pacientes com diagnóstico confirmado de MPS tipos I, II, III, IV e VI foram incluídos (29 do sexo masculino e 18 do sexo feminino; idade entre 0,8 e 36,9 anos). Espaços perivasculares alargados foram comumente encontrados no mesencéfalo e adjacente ao núcleo denteado (em 85% e 55% dos indivíduos, respectivamente), apresentando pequenas dimensões (maior diâmetro axial médio: 0,24 cm ± 0,06 cm). Lesões de substância branca foram identificadas qualitativamente na ponte e no cerebelo com maior frequência (em 34% e 30% dos pacientes, respectivamente). O volume cerebelar foi classificado como normal em 38% dos pacientes, assim como o macrocerebelo foi identificado em outros 38%. Os valores da espessura média dos PCMs nos planos sagital e axial foram de 1,17 cm (SD ± 0,17 cm) e 1,66 cm (SD ± 0,17 cm), respectivamente. A fossa posterior foi identificada como de tamanho normal na maioria dos pacientes (97%). Em relação ao formato, a depressão no assoalho da fossa posterior na linha média, avaliada no plano sagital e denominada de fossa posterior em J-invertido, foi encontrada em 47% dos pacientes. Alargamento dos espaços liquóricos na fossa posterior estava presente em 55% dos indivíduos. No presente estudo, foi encontrada associação entre fossa posterior em J invertido e a presença de macrocerebelo ou de alargamento dos espaços liquóricos (teste exato de Fischer p = 0,04 para ambas análises). Conclusão: Dois novos achados foram descritos no atual estudo: fossa posterior em J invertido e aparente espessamento dos PCMs. Na população descrita, a fossa posterior em J invertido esteve associada com a presença de macrocerebelo ou de alargamento dos espaços liquóricos.Background: Mucopolysaccharidosis (MPS) is a hereditary multisystemic metabolic disease part of the group of lysosomal storage disorders. Central nervous system is highly affected in MPS patients, and magnetic resonance (MR) imaging is the method of choice for neuroaxis evaluation. Most imaging studies in MPS focus on supratentorial compartment and craniocervical junction abnormalities, while studies specifically describing posterior fossa findings in these patients are scarce. Aim: To describe the posterior fossa findings observed in MR imaging studies of MPS patients. Methods: It was conducted a cross-sectional study including all confirmed MPS cases from genetic division of a university hospital in southern Brazil who underwent a routine brain MR imaging. Images were evaluated by consensus of two experienced radiologists. It was performed a qualitative evaluation of white matter lesions on brain stem and cerebellum, cerebellar volume, posterior fossa shape and size, and enlargement of cerebrospinal fluid (CSF) spaces. Enlarged perivascular spaces and middle cerebellar peduncle (MCP) width were quantitatively assessed. Fisher’s exact test was used to evaluate the association between inverted J-shaped posterior fossa and macrocerebellum and enlargement of CSF spaces. Results: A total of 47 patients with confirmed diagnosis of MPS was included (29 males and 18 females; age range, 0.8 - 36.9 years), with I, II, III, IV and VI types. Enlarged perivascular spaces were commonly found in midbrain and adjacent to the dentate nuclei (present in 85% and 55% of individuals, respectively), and they were usually small (mean maximum axial diameter, 0.24 cm ± 0.06 cm). Areas of white matter lesion were qualitatively identified most frequently in the pons and in the cerebellum (in 34% and 30% of the patients, respectively). Cerebellar volume was qualitatively classified as normal in 38% of patients and macrocerebellum also was identified in 38% of individuals. Mean MCP width in sagittal and in axial planes in MPS patients were 1.17 cm (SD ± 0.17 cm) and 1.66 cm (SD ± 0.17 cm), respectively. Most patients have a normal posterior fossa size (97%). Regarding the shape, a depression of the posterior fossa floor in midline sagittal plane, defined as an inverted J-shaped posterior fossa, was found in 47% of patients. Enlargement of CSF spaces in the posterior fossa was present in 55% of individuals. In this study, inverted J-shaped posterior fossa was associated with the presence of macrocerebellum and enlargement of CSF spaces (Fisher’s exact test p-value = 0.04 for both analyses). Conclusion: Two new findings were described in the present study: inverted J-shaped posterior fossa and thickened aspect of MCPs. Inverted J-shaped posterior fossa was associated with the presence of macrocerebellum and enlargement of CSF spaces in this population

Metabolic syndrome and physical activity in southern Brazilian community-dwelling elders: a population-based, cross-sectional study

<p>Abstract</p> <p>Background -</p> <p>The association between a sedentary lifestyle and obesity is well documented, and is linked to an increased prevalence of metabolic syndrome (MS). There is some evidence that information regarding the health benefits of physical activity is beginning to impact on the elderly people and is beginning to change their behavior. We aimed to investigate the level of physical activity undertaken by elderly people with MS and those without this condition.</p> <p>Methods -</p> <p>We evaluated 362 community-dwelling elders of Novo Hamburgo, southern Brazil. Diagnosis of MS was based on the International Diabetes Federation criteria and the physical activity (PA) level was estimated by the International Physical Activity Questionnaire. Analysis of covariance was carried out to verify associations between MS risk factors and the level of PA. Logistic regression was used to estimate the MS odds ratio for each level of PA.</p> <p>Results -</p> <p>No significant association was found between MS and the level of physical activity, irrespective of sex. The odds ratio for the presence of MS adjusted for sex and age and using insufficiently active elderly people as reference was 1.04 (95% CI, 0.6 to 1.7) in sufficiently active elderly people and 1.15 (95% CI, 0.7 to 2.0) in very active elderly people.</p> <p>Conclusion -</p> <p>The elderly citizens of a southern Brazilian community who were diagnosed with MS presented the same levels of PA as the individuals who did not have this diagnosis. This may imply that information on the importance of physical activity has already reached this higher risk population.</p

Adrenal collision tumor: Renal carcinoma metastasis within adrenal adenoma

Collision tumors are defined as the presence of two contiguous histologically different lesions composed of benign and/or malignant components. They are infrequent entities and have been reported in various organs and systems. The most common type of collision tumor in the adrenal gland is the association of two benign lesions, adenoma and myelolipoma. Modification in image characteristics or unexpected growth of an adrenal tumor previously characterized as a benign lesion should be suspicious for collision tumor with a new aggressive component. In this article, we present a case of renal carcinoma metastasis within a previously known adrenal adenoma

Magnetic resonance imaging findings of the posterior fossa in 47 patients with mucopolysaccharidoses : a cross-sectional analysis

Background: Mucopolysaccharidoses (MPS) is a group of hereditary multisystemic lysosomal disorders. Most neuroimaging studies in MPS have focused on the supratentorial compartment and craniocervical junction abnormalities, and data regarding posterior fossa findings are scarce in the literature. Thus, our purpose is to describe posterior fossa findings on magnetic resonance imaging (MRI) of MPS patients. Methods: We reviewed routine MRI scans of MPS patients being followed up at our institution (types I, II, III, IV, and VI), focusing on posterior fossa structures. Results: Forty-seven MPS patients were included. MRI-visible perivascular spaces were commonly found in the midbrain and adjacent to the dentate nuclei (85% and 55% of patients, respectively). White-matter lesion was not identified in most cases. Its most frequent localizations were in the pons and cerebellum (34% and 30% of patients, respectively). Enlargement of cerebrospinal fluid (CSF) spaces in the posterior fossa was present in 55% of individuals and was more frequent in neuronopathic patients (73% vs 40%; P = .02). Cerebellar volume was classified as normal, apparent macrocerebellum, atrophic, and hypoplastic in 38%, 38%, 21%, and 3% of patients, respectively. A depression of the posterior fossa floor in the midline sagittal plane was found in 22 patients (47%), which was statistical significantly associated with enlargement of CSF spaces (P = .02) and with apparent macrocerebellum (P = .03). Conclusion: The present study compiled the main posterior fossa findings in MPS patients. Classically described in the supratentorial compartment, MRI-visible perivascular spaces, white matter lesions, and enlarged perivascular spaces were also found in the posterior fossa. However, atrophy, which commonly affects cerebral hemispheres, was not the most frequent cerebellar morphology found in our study. Moreover, potential findings for future research were described

New and atypical combinations: An assessment of novelty and interdisciplinarity

Novelty indicators are increasingly important for science policy. This paper challenges the indicators of novelty as an atypical combination of knowledge (Uzzi et al., 2013) and as the first appearance of a knowledge combination (Wang et al., 2017). We exploit a sample of 230,854 articles (1985 - 2005), published on 8 journals of the American Physical Society (APS) and 2.4 million citations to test the indicators using (i) a Configuration Null Model, (ii) an external validation set of articles related to Nobel Prize winning researches and APS Milestones, (iii) a set of established interdisciplinarity indicators, and (iv) the relationship with the articles\u2019 impact. We find that novelty as the first appearance of a knowledge combination captures the key structural properties of the citation network and finds it difficult to tell novel and non-novel articles apart, while novelty as an atypical combination of knowledge overlaps with interdisciplinarity. We suggest that the policy evidence derived from these measures should be reassessed