Abnormal frontal cortex white matter connections in bipolar disorder: A DTI tractography study (original) (raw)
Related papers
Revista brasileira de psiquiatria (Sao Paulo, Brazil : 1999), 2016
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. 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. 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. Despite considerable heterogeneity, these results indicate a direct link between executive cognitive functioning and abnormal WM microstructural in...
Psychiatry and clinical neurosciences, 2017
To compare white matter structural changes in specific tracts by diffusion tensor imaging (DTI) tractography in patients of bipolar disorder I, non-ill first degree relatives of the patients, and healthy controls. In a cross sectional study, we studied right-handed subjects consisting of 16 euthymic bipolar disorder I patients, 15 first degree relatives and 15 healthy controls. The anterior thalamic radiation, uncinate fasciculus, corpus callosum, and cingulum bundle were reconstructed by DTI tractography. Mean fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were compared for group differences followed by post hoc analysis. The three groups did not differ in terms of socio-demographic variables. There were significant group differences in the FA values between the bipolar disorder I, first degree relatives and the healthy control groups for corpus callosum, dorsal part of right cingulum bundle, hippocampal part of cingulum bundle bilaterally, and uncinate ...
Journal of psychiatry & neuroscience : JPN, 2018
An increasing number of psychoradiology studies that use tract-based spatial statistics (TBSS) of diffusion tensor imaging have reported abnormalities of white matter in patients with bipolar disorder; however, robust conclusions have proven elusive, especially considering some important clinical and demographic factors. In the present study, we performed a quantitative meta-analysis of TBSS studies to elucidate the most consistent white-matter abnormalities in patients with bipolar disorder. We conducted a systematic search up to May 2017 for all TBSS studies comparing fractional anisotropy (FA) between patients with bipolar disorder and healthy controls. We performed anisotropic effect size-signed differential mapping meta-analysis. We identified a total of 22 data sets including 556 patients with bipolar disorder and 623 healthy controls. We found significant FA reductions in the genu and body of the corpus callosum in patients with bipolar disorder relative to healthy controls. ...
Bipolar Disorders, 2009
Objectives: Strong qualitative and quantitative evidence exists of white matter abnormalities in both schizophrenia and bipolar disorder (BD). Diffusion tensor imaging (DTI) studies suggest altered connectivity in both disorders. We aim to address the diagnostic specificity of white matter abnormalities in these disorders.Methods: DTI was used to assess white matter integrity in clinically stable patients with familial BD (n = 42) and familial schizophrenia (n = 28), and in controls (n = 38). Differences in fractional anisotropy (FA) were measured using voxel-based morphometry and automated region of interest analysis.Results: Reduced FA was found in the anterior limb of the internal capsule (ALIC), anterior thalamic radiation (ATR), and in the region of the uncinate fasciculus in patients with BD and those with schizophrenia compared with controls. A direct comparison between patient groups found no significant differences in these regions. None of the findings were associated with psychotropic medication.Conclusions: Reduced integrity of the ALIC, uncinate fasciculus, and ATR regions is common to both schizophrenia and BD. These results imply an overlap in white matter pathology, possibly relating to risk factors common to both disorders.
NeuroImage. Clinical, 2013
Bipolar disorder (BD) is a chronic mental illness characterized by severe disruptions in mood and cognition. Diffusion tensor imaging (DTI) studies suggest that white matter (WM) tract abnormalities may contribute to the clinical hallmarks of the disorder. Using DTI and whole brain voxel-based analysis, we mapped the profile of WM anomalies in BD. All patients in our sample were euthymic and lithium free when scanned. Diffusion-weighted and T1-weighted structural brain images were acquired from 23 lithium-free euthymic subjects with bipolar I disorder and 19 age- and sex-matched healthy control subjects on a 1.5 T MRI scanner. Scans were processed to provide measures of fractional anisotropy (FA) and mean and radial diffusivity (MD and RD) at each WM voxel, and processed scans were nonlinearly aligned to a customized brain imaging template for statistical group comparisons. Relative to controls, the bipolar group showed widespread regions of lower FA, including the corpus callosum, ...
White matter abnormalities observed in bipolar disorder: a diffusion tensor imaging study
Bipolar Disorders, 2007
Neuroimaging technology has provided a number of new methods that have significantly advanced our knowledge of structural and functional deficits associated with psychiatric illnesses. In bipolar disorder (BPD), one of the most frequently reported brain abnormalities is the appearance of white matter hyperintensities (WMHs) (1-4), although non-significant differences in the prevalence or severity of WMHs between bipolar patients and healthy comparison subjects have also been reported (5). It has been hypothesized that WMHs result from localized changes in water content, which may play an important role in the neurocognitive deficits observed in BPD (6). Results from morphometry studies conducted in bipolar patients have been more mixed, with some studies documenting no overall differences in white matter volume between bipolar patients and controls (7, 8), several reporting significantly reduced white matter volume in bipolar I disorder (9, 10), and others reporting a trend for decreased white matter volume in first Yurgelun-Todd DA, Silveri MM, Gruber SA, Rohan ML, Pimentel PJ. White matter abnormalities observed in bipolar disorder: a diffusion tensor imaging study.
Molecular Psychiatry, 2007
Bipolar disorder has been associated with anatomical as well as functional abnormalities in a brain network that mediates normal and impaired emotion regulation. Previous brain imaging studies have highlighted the subgenual cingulate (SC) and the amygdalo-hippocampal (AH) complex as core regions of this network. Thus we investigated white matter (WM) fiber tracts between the SC and the AH region, the uncinate fasciculus, as well as between two control regions (pons and cerebellum), using diffusion tensor imaging tractography in 16 euthymic bipolar patients (BP) and 16 sex-, age-and handedness-matched controls. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of the reconstructed fiber bundle and the number of virtual reconstructed fibers were compared between groups. The tractography results revealed a significantly increased number of reconstructed fibers between the left SC and left AH in BP as compared to healthy controls. FA and ADC of the reconstructed fiber tract did not differ significantly between the groups. Furthermore, no significant group differences were observed neither for reconstructed fiber tracts between the right SC and right AH nor between the control regions. The present results suggest an altered WM pathway between the left SC and AH region and thus extend previous findings of anatomical and functional modifications in these structures in BP.