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

Abstract

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.

Examination of retinal vascular trajectory in schizophrenia and bipolar disorder

“…However, the brain correlates of thin RNFL have not directly been examined in SCZ and BD to date. Considering the relation between retinal arterial trajectory and RNFL thickness, it is possible that the abnormalities in retinal vascular trajectory may also be related to the structural brain abnormalities seen in SCZ and BD . However, this speculation is based on indirect evidence as the relation between retinal vascular trajectory and brain structure/function in SCZ or BD remains to be explored.…”

Aberrant Anterior Thalamic Radiation Structure in Bipolar Disorder: A Diffusion Tensor Tractography Study

“…A growing number of neuroimaging studies have revealed that frontal-limbic neuronal networks may play an important role in cognitive and emotional processing in BD ( 2 ). Diffusion tensor imaging (DTI) is a technique used to examine connectivity in the brain, and studies have identified atypical structural connectivity in individuals with BD ( 3 ). The anterior thalamic radiation (ATR) is a white matter (WM) fiber bundle connecting the prefrontal cortex (mainly in the dorsolateral prefrontal cortex) and the thalamus through the anterior limb of the internal capsule.…”

Acurácia diagnóstica em sujeitos adultos com TDAH e transtorno bipolar: classificação individual de imagens de ressonância magnética de crânio

“…Isso porque que, em geral, não é possível mapear com precisão os pesos utilizados pelo classificador, de volta ao espaço cerebral do voxel (Haufe et al, 2014;Wolfers et al, 2015). Outro ponto relevante está relacionado ao fato de que os pesos associados a um local cerebral específico podem mudar como consequência da reconfiguração do padrão multivariado, por exemplo, devido a variações nas seleções das características (Wolfers et al, 2015 (Caseras et al, 2015;Phillips et al, 2008 (Benedetti et al, 2011;Duarte et al, 2016;Sprooten et al, 2011). Quando as características estruturais foram adicionadas aos dados de DTI, o desempenho diagnóstico ficou bastante similar, mostrando que a adição das informações estruturais não proporcionou uma contribuição significativa para a classificação.…”