Diffusion tensor imaging detects white matter abnormalities and associated cognitive deficits in chronic adolescent TBI
ABSTRACT Primary objective: This study examined long-term alterations in white matter microstructure following TBI in adolescence using diffusion tensor imaging (DTI). It was hypothesized that white matter integrity would be compromised in adolescents with TBI and would correlate with measures of executive functioning and cognitive abilities. Research design: This study employed whole-brain, voxel-wise, statistical comparison of DTI indices in youth of 12-17 years old (mean = 15.06) with TBI vs an age- and gender-matched cohort (mean age = 15.37). Methods and procedures: This study scanned 17 adolescents with complicated-mild-to-severe TBI, 1-3 years after injury, and 13 healthy adolescents. Tract-Based Spatial Statistics (TBSS) was employed for DTI analysis. Main outcomes and results: Overall diffusivity elevations were found in the TBI group with increases in axial diffusivity in the right hemisphere. White matter integrity was associated with word reading, planning and processing times in the TBI group, but not healthy controls. Conclusions: The detected abnormalities in axial diffusivity may reflect neuronal regeneration and cerebral reorganization after injury. These findings provide tentative evidence of persistent white matter alteration following TBI in adolescence. Associations of DTI indices with cognitive performance following TBI provide tentative support for links between white matter integrity and performance post-TBI.
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ABSTRACT: The Behavior Rating Inventory of Executive Function (BRIEF) is a rating scale designed to assess executive functions in everyday life that is widely used in school and clinical settings and in research studies. It has been recently suggested, however, that the limited geographic stratification of the standardization sample renders the measure overly sensitive. We evaluated this hypothesis by examining BRIEF scores across studies of typically developing children and adolescents. Thirty-nine studies were identified that included at least one of three possible index scores. Mean scores across studies were (a) within one to two T-score units from the standardization sample mean of 50, (b) tended to be slightly lower than 50, and (c) were unrelated to geographic location (US Census regions or internationally). These findings refute recent claims that the BRIEF is overly sensitive and further add to the large body of literature supporting the validity of the measure.Child Neuropsychology 03/2014; DOI:10.1080/09297049.2014.897318 · 2.18 Impact Factor
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ABSTRACT: To investigate structural brain changes in inflammatory bowel disease (IBD). Brain magnetic resonance imaging (MRI) was performed on 18 IBD patients (aged 45.16 +/- 14.71 years) and 20 aged-matched control subjects. The imaging protocol consisted of a sagittal-FLAIR, a T1-weighted high-resolution three-dimensional spoiled gradient-echo sequence, and a multisession spin-echo echo-planar diffusion-weighted sequence. Differences between patients and controls in brain volume and diffusion indices were evaluated using the voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) methods, respectively. The presence of white-matter hyperintensities (WMHIs) was evaluated on FLAIR images. VBM revealed decreased grey matter (GM) volume in patients in the fusiform and the inferior temporal gyrus bilaterally, the right precentral gyrus, the right supplementary motor area, the right middle frontal gyrus and the left superior parietal gyrus (p < 0.05). TBSS showed decreased axial diffusivity (AD) in the right corticospinal tract and the right superior longitudinal fasciculus in patients compared with controls. A larger number of WMHIs was observed in patients (p < 0.05). Patients with IBD show an increase in WMHIs and GM atrophy, probably related to cerebral vasculitis and ischaemia. Decreased AD in major white matter tracts could be a secondary phenomenon, representing Wallerian degeneration. aEuro cent There is evidence of central nervous system involvement in IBD. aEuro cent Diffusion tensor imaging detects microstructural brain abnormalities in IBD. aEuro cent Voxel based morphometry reveals brain atrophy in IBD.European Radiology 07/2014; 24(10). DOI:10.1007/s00330-014-3242-6 · 4.34 Impact Factor
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ABSTRACT: This study meta-analyzed research examining Diffusion Tensor Imaging following pediatric non-penetrating traumatic brain injury to identify the location and extent of white matter changes. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) data from 20 studies were analyzed. FA increased and ADC decreased in most white matter tracts in the short-term (moderate-to-large effects), and FA decreased and ADC increased in the medium- to long-term (moderate-to-very-large effects). Whole brain (short-term), cerebellum and corpus callosum (medium- to long-term) FA values have diagnostic potential, but the impact of age/developmental stage and injury severity on FA/ADC, and the predictive value, is unclear.Developmental Neuropsychology 12/2014; 39(8):600-37. DOI:10.1080/87565641.2014.973958 · 2.67 Impact Factor