Microstructural White Matter Changes in the Corpus Callosum of Young People with Bipolar Disorder: A Diffusion Tensor Imaging Study

Abstract

To date, most studies of white matter changes in Bipolar Disorder (BD) have been conducted in older subjects and with well-established disorders. Studies of young people who are closer to their illness onset may help to identify core neurobiological characteristics and separate these from consequences of repeated illness episodes or prolonged treatment. Diffusion tensor imaging (DTI) was used to examine white matter microstructural changes in 58 young patients with BD (mean age 23 years; range 16–30 years) and 40 controls. Whole brain voxelwise measures of fractional anisotropy (FA), parallel diffusivity (λ//) and radial diffusivity (λ⊥) were calculated for all subjects. White matter microstructure differences (decreased FA corrected p<.05) were found between the patients with BD and controls in the genu, body and splenium of the corpus callosum as well as the superior and anterior corona radiata. In addition, significantly increased radial diffusivity (p<.01) was found in the BD group. Neuroimaging studies of young patients with BD may help to clarify neurodevelopmental aspects of the illness and for identifying biomarkers of disease onset and progression. Our findings provide evidence of microstructural white matter changes early in the course of illness within the corpus callosum and the nature of these changes suggest they are associated with abnormalities in the myelination of axons.

Reduced white matter integrity and verbal fluency impairment in young adults with bipolar disorder: A diffusion tensor imaging study

“…The corpus callosum and thalamic radiation of middle-aged and drug-naïve BD populations showed abnormal axial (AD) and radial diffusivity (RD) values [21-23]. Increased RD values have been observed in the cingulum, the superior and inferior uncinated fasciculus, the corpus callosum and the internal capsule of BD I patients when compared to their unaffected relatives and healthy controls [24].…”

Methadone use in a male with the FMRI premutation and FXTAS

“…In other neurodegenerative diseases, white matter disease (WMD) is associated with cognitive impairment [Prins et al, 2005; Gouw et al, 2006], physical decline [Zheng et al, 2012] and depressive symptoms in the elderly [de Groot et al, 2000]. Furthermore, WMD occurs in schizophrenia [Voineskos et al, 2013] and bipolar disorder [Ahn et al, 2004; Lagopoulos et al, 2013], and is correlated with mortality in patients with and without dementia or stroke [Bokura et al, 2006; Kerber et al, 2006; Kuller et al, 2007; Ikram et al, 2009; Oksala et al, 2009]. …”

Corpus callosal morphology in youth with bipolar depression

“…Reduced signal intensity in youth with BD has been identified in all callosal subregions , a finding that has been replicated in adults with BD . Finally, a diffusion tensor imaging study revealed decreased structural integrity across the length of the corpus callosum in youth with BD ; the authors speculated that this may negatively influence attention and executive functioning. Nevertheless, the contribution of corpus callosum abnormalities in youth with BD remains unclear.…”