Diffusion Tensor Imaging Study of White Matter Fiber Tracts in Pediatric Bipolar Disorder and Attention-Deficit/Hyperactivity Disorder

Abstract

Objective-To investigate microstructure of white matter fiber tracts in pediatric bipolar disorder (PBD) and attention deficit hyperactivity disorder (ADHD).Methods-A diffusion tensor imaging (DTI) study was conducted at 3 Tesla on age and IQ-matched children and adolescents with PBD (n=13), ADHD (n=13), and healthy controls (HC) (n=15). Three DTI parameters, fractional anisotropy (FA), apparent diffusion coefficient (ADC), and regional fiber coherence index (r-FCI), were examined in eight fiber tracts: Anterior corona radiata (ACR); anterior limb of the internal capsule (ALIC); superior region of the internal capsule (SRI); posterior limb of the internal capsule (PLIC); superior longitudinal fasciculus (SLF); inferior longitudinal fasciculus (ILF); cingulum (CG); splenium (SP).Results-Significantly lower FA was observed in ACR in both PBD and ADHD relative to HC. In addition, FA and r-FCI values were significantly lower in ADHD relative to PBD and HC in both the ALIC and the SRI. Further, ADC was significantly greater in ADHD relative to both the PBD and HC in ACR, ALIC, PLIC, SRI, CG, ILF, and SLF. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Conclusions-Decreased FA in ACR implies an impaired fiber density or reduced myelination in both PBD and ADHD in this prefrontal tract. These abnormalities, together with the reduced fiber coherence, extended to cortico-bulbar tracts in ADHD. Increased ADC across multiple white matter tracts in ADHD indicates extensive cellular abnormalities with less diffusion restriction in ADHD relative to PBD. NIH Public Access

Attention-Deficit/Hyperactivity Disorder and Attention Networks

“…Lower corticospinal tract and superior longitudinal fasciculus FA (Hamilton et al, 2008) similarly suggested disruption of motor and attention networks in ADHD children, whereas the study by Silk et al (2008) indicated that fronto-striatal and fronto-parietal circuitry abnormalities exist in children with ADHD. Finally, pediatric samples showed decreased FA in the anterior corona radiata and abnormalities across multiple white matter tracts in ADHD, including the cingulum bundle, the superior and inferior longitudinal fasciculi, and internal capsule (Pavuluri et al, 2009). Together, the data argue that white matter abnormalities are associated with ADHD.…”

Combined analysis of grey matter voxel-based morphometry and white matter tract-based spatial statistics in late-life bipolar disorder

“…Overall, the few previous DTI studies reported reduced fractional anisotropy and increased radial diffusion in the frontal and prefrontal lobes, internal capsule, corpus callosum and uncinate fasciculus of patients with bipolar disorder. [18][19][20][21][22][23][24] Tract-based spatial statistics (TBSS) is a recently introduced advanced analysis technique that projects all individual DTI parameters onto a group average white matter skeleton, reducing potential spatial misregistrations. 25 Only 2 TBSS studies were performed in young patients with bipolar disorder, showing a reduction in fractional anisotropy, notably in the corpus callosum and fornix 22 as well as in the right uncinate fasciculus.…”

Multimodal imaging of the self-regulating developing brain

“…Although development of self-regulation in children is the result of a dynamic interaction between maturation and learning, we have scarce knowledge about the role played by structural brain characteristics in this process. Recent reports indicate that adjustment problems in childhood psychopathology are related to structural brain characteristics (9)(10)(11)(12)(13), but the brain basis for development of self-regulation in normal children is less well-understood. Thus, the purpose of the present paper was to use multimodal neuroimaging to map the structural brain characteristics related to self-regulation and cognitive control in a large sample of 735 children between 4 and 21 y of age.…”