Neurobiological underpinnings of bipolar disorder focusing on findings of diffusion tensor imaging: a systematic review

Objective: To review the available data on diffusion tensor imaging (DTI) of subjects with bipolar disorder (BD), with a particular focus on fractional anisotropy (FA) in white matter (WM) tracts. Methods: The PubMed/MEDLINE database was searched for relevant articles, which were included in a systematic review of the literature. FA reductions and WM abnormalities were divided anatomically into three groups: commissural tracts, association tracts, and projection tracts. Results: Eighteen studies met the inclusion criteria. The corpus callosum was the main impaired commissural tract as demonstrated by FA reductions. Five studies reported FA reductions in the cingulum. Two studies reported decreased FA in the anterior thalamic radiation, and one in the corticospinal tract. Conversely, three studies found increased FA values in WM tracts involved in BD pathophysiology. Conclusion: Despite considerable heterogeneity, these results indicate a direct link between executive cognitive functioning and abnormal WM microstructural integrity of fronto-limbic tracts in patients with remitted BD, providing further evidence of the neuronal disruption that underlies BD symptomatology.

Grau de escolaridade materna e baixo peso ao nascer: uma meta-análise / Maternal education level and low birth weight: a meta-analysis

OBJETIVO: Analisar a associação entre grau de escolaridade materna e peso de nascimento, considerando-se a hipótese de que a utilização em excesso das tecnologias na área da saúde, assim como a escassez de recursos, pode produzir desfechos similares. MÉTODOS: Realizou-se uma meta-análise com estudos transversais e de coorte, selecionados por revisão sistemática na base de dados bibliográficos MEDLINE com os descritores: socioeconomic factors; infant, low birth weight; cohort studies; cross-sectional studies. As medidas de sumário de efeito foram obtidas pelo modelo de efeito aleatório, e os seus resultados apresentados por intermédio dos gráficos Forest Plot. O viés de publicação foi analisado pelo Teste de Egger, e a avaliação da qualidade dos estudos utilizou a Escala de Newcastle-Ottawa. RESULTADOS: A busca inicial encontrou 729 artigos. Destes, foram excluídos 594, após a leitura do título e do resumo; 21, após reuniões de consenso entre os três revisores; 102, após leitura do texto completo; e três, por não possuírem o desfecho adequado. Dos nove artigos finais, 88,8% apresentavam uma qualidade igual ou superior a seis estrelas (Escala de Newcastle-Ottawa), configurando boa qualidade aos estudos. A heterogeneidade dos artigos foi considerada moderada. A escolaridade materna elevada mostrou um efeito protetor de 33% sobre o baixo peso ao nascer, enquanto que o grau médio não apresentou proteção significativa, quando comparados à escolaridade materna baixa. CONCLUSÕES: A hipótese de similaridade entre os graus extremos da distribuição social, traduzidas pelo nível de escolaridade materna, em relação à proporção de baixo peso ao nascer, não foi confirmada.

OBJECTIVE: To assess the association between maternal education level and birth weight, considering the circumstances in which the excess use of technology in healthcare, as well as the scarcity of these resources, may result in similar outcomes. METHODS: A meta-analysis of cohort and cross-sectional studies was performed; the studies were selected by systematic review in the MEDLINE database using the following key words: socioeconomic factors, infant, low birth weight, cohort studies, cross-sectional studies. The summary measures of effect were obtained by random effect model, and its results were obtained through forest plot graphs. The publication bias was assessed by Egger’s test, and the Newcastle-Ottawa scale was used to assess study quality. RESULTS: The initial search found 729 articles. Of these, 594 were excluded after reading the title and abstract; 21, after consensus meetings among the three reviewers; 102, after reading the full text; and three for not having the proper outcome. Of the nine final articles, 88.8% had quality > six stars (Newcastle-Ottawa Scale), showing good quality studies. The heterogeneity of the articles was considered moderate. High maternal education showed a 33% protective effect against low birth weight, whereas medium degree of education showed no significant protection when compared to low maternal education. CONCLUSIONS: The hypothesis of similarity between the extreme degrees of social distribution, translated by maternal education level in relation to the proportion of low birth weight, was not confirmed.