White-matter relaxation time and myelin water fraction differences in young adults with autism

2014 ◽  
Vol 45 (4) ◽  
pp. 795-805 ◽  
Author(s):  
S. C. L. Deoni ◽  
J. R. Zinkstok ◽  
E. Daly ◽  
C. Ecker ◽  
S. C. R. Williams ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Brain Connectivity ◽  
Critical Role ◽  
Relaxation Times ◽  
Imaging Study ◽  
Autism Diagnostic Observation Schedule ◽  
Cross Sectional ◽  
Water Fraction ◽  
Myelin Water Fraction

BackgroundIncreasing evidence suggests that autism is associated with abnormal white-matter (WM) anatomy and impaired brain ‘connectivity’. While myelin plays a critical role in synchronized brain communication, its aetiological role in autistic symptoms has only been indirectly addressed by WM volumetric, relaxometry and diffusion tensor imaging studies. A potentially more specific measure of myelin content, termed myelin water fraction (MWF), could provide improved sensitivity to myelin alteration in autism.MethodWe performed a cross-sectional imaging study that compared 14 individuals with autism and 14 age- and IQ-matched controls. T1 relaxation times (T1), T2 relaxation times (T2) and MWF values were compared between autistic subjects, diagnosed using the Autism Diagnostic Interview – Revised (ADI-R), with current symptoms assessed using the Autism Diagnostic Observation Schedule (ADOS) and typical healthy controls. Correlations between T1, T2 and MWF values with clinical measures [ADI-R, ADOS, and the Autism Quotient (AQ)] were also assessed.ResultsIndividuals with autism showed widespread WM T1 and MWF differences compared to typical controls. Within autistic individuals, worse current social interaction skill as measured by the ADOS was related to reduced MWF although not T1. No significant differences or correlations with symptoms were observed with respect to T2.ConclusionsAutistic individuals have significantly lower global MWF and higher T1, suggesting widespread alteration in tissue microstructure and biochemistry. Areas of difference, including thalamic projections, cerebellum and cingulum, have previously been implicated in the disorder; however, this is the first study to specifically indicate myelin alteration in these regions.

Brain connectivity in body dysmorphic disorder compared with controls: a diffusion tensor imaging study

2013 ◽  
Vol 43 (12) ◽  
pp. 2513-2521 ◽  
Author(s):  
B. G. Buchanan ◽  
S. L. Rossell ◽  
J. J. Maller ◽  
W. L. Toh ◽  
S. Brennan ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Body Dysmorphic Disorder ◽  
Diffusion Tensor ◽  
Brain Connectivity ◽  
Imaging Study ◽  
Healthy Controls ◽  
Caudate Nuclei ◽  
White Matter Connectivity ◽  
The Brain

BackgroundSeveral neuroimaging studies have investigated brain grey matter in people with body dysmorphic disorder (BDD), showing possible abnormalities in the limbic system, orbitofrontal cortex, caudate nuclei and temporal lobes. This study takes these findings forward by investigating white matter properties in BDD compared with controls using diffusion tensor imaging. It was hypothesized that the BDD sample would have widespread significantly reduced white matter connectivity as characterized by fractional anisotropy (FA).MethodA total of 20 participants with BDD and 20 healthy controls matched on age, gender and handedness underwent diffusion tensor imaging. FA, a measure of water diffusion within a voxel, was compared between groups on a voxel-by-voxel basis across the brain using tract-based spatial statistics within the FSL package.ResultsResults showed that, compared with healthy controls, BDD patients demonstrated significantly lower FA (p < 0.05) in most major white matter tracts throughout the brain, including in the superior longitudinal fasciculus, inferior fronto-occipital fasciculus and corpus callosum. Lower FA levels could be accounted for by increased radial diffusivity as characterized by eigenvalues 2 and 3. No area of higher FA was found in BDD.ConclusionsThis study provided the first evidence of compromised white matter integrity within BDD patients. This suggests that there are inefficient connections between different brain areas, which may explain the cognitive and emotion regulation deficits within BDD patients.

White matter development during late adolescence in healthy males: A cross-sectional diffusion tensor imaging study

NeuroImage ◽  
2007 ◽  
Vol 35 (2) ◽  
pp. 501-510 ◽  
Author(s):  
Manzar Ashtari ◽  
Kelly L. Cervellione ◽  
Khader M. Hasan ◽  
Jinghui Wu ◽  
Carolyn McIlree ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Diffusion Tensor ◽  
Imaging Study ◽  
Late Adolescence ◽  
Cross Sectional ◽  
White Matter Development ◽  
Diffusion Tensor Imaging Study ◽  
Healthy Males

scholarly journals White Matter Development During Childhood and Adolescence: A Cross-sectional Diffusion Tensor Imaging Study

2005 ◽  
Vol 15 (12) ◽  
pp. 1848-1854 ◽  
Author(s):  
Naama Barnea-Goraly ◽  
Vinod Menon ◽  
Mark Eckert ◽  
Leanne Tamm ◽  
Roland Bammer ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Diffusion Tensor ◽  
Imaging Study ◽  
Childhood And Adolescence ◽  
Cross Sectional ◽  
White Matter Development ◽  
Diffusion Tensor Imaging Study

scholarly journals Myelination of major white matter tracts continues beyond childhood—combining tractography and myelin water imaging

2019 ◽  
Author(s):  
Tobias W. Meissner ◽  
Erhan Genç ◽  
Burkhard Mädler ◽  
Sarah Weigelt
Keyword(s):  
White Matter ◽  
Middle Childhood ◽  
Diffusion Tensor ◽  
Late Childhood ◽  
White Matter Tracts ◽  
Water Fraction ◽  
White Matter Maturation ◽  
Myelin Water Fraction ◽  
Diffusion Tensor Imaging Dti

AbstractAxonal myelination is a key white matter maturation process as it increases conduction velocity, synchrony, and reliability. While diffusion tensor imaging (DTI) is sensitive to myelination, it is also sensitive to unrelated microstructural properties, thus hindering straightforward interpretations. Myelin water imaging (MWI) provides a more reliable and direct in vivo measure of myelination. Although early histological studies show protracted myelination from childhood to adulthood, reliable tract-specific in vivo evidence from MWI is still lacking. Here, we combine MWI and DTI tractography to investigate myelination in middle childhood, late childhood, and adulthood in 18 major white matter tracts. In the vast majority of major white matter tracts, myelin water fraction continued to increase beyond late childhood. Our study provides first in vivo evidence for protracted myelination beyond late childhood.

scholarly journals White Matter Integrity in Genetic High-Risk Individuals and First-Episode Schizophrenia Patients: Similarities and Disassociations

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Yifang Zhou ◽  
Jie Liu ◽  
Naomi Driesen ◽  
Fay Womer ◽  
Kaiyuan Chen ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Imaging Study ◽  
First Episode ◽  
Cross Sectional ◽  
Executive Performance ◽  
High Genetic Risk ◽  
Cognitive Disturbances ◽  
First Episode Schizophrenia ◽  
Diffusion Tensor Imaging Study

White matter (WM) neuroimaging studies have shown varied findings at different stages of schizophrenia (SZ). Understanding these variations may elucidate distinct markers of genetic vulnerability and conversion to psychosis. To examine the similarities and differences in WM connectivity between those at-risk for and in early stages of SZ, a cross-sectional diffusion tensor imaging study of 48 individuals diagnosed with first-episode SZ (FE-SZ), 37 nonpsychotic individuals at a high genetic risk of SZ (GHR-SZ), and 67 healthy controls (HC) was conducted. Decreased fractional anisotropy (FA) in the corpus callosum (CC), anterior cingulum (AC), and uncinate fasciculus (UF) was observed in both the GHR-SZ and FE-SZ groups, while decreased FAs in the superior longitudinal fasciculus (SLF) and the fornix were only seen in the FE-SZ participants. Additionally, both GHR-SZ and FE-SZ showed worse executive performance than HC. The left SLF III FA was significantly positively correlated with hallucinations, and right SLF II was positively correlated with thought disorder. The presence of shared WM deficits in both FE-SZ and GHR-SZ individuals may reflect the genetic liability to SZ, while the disparate FA changes in the FE-SZ group may represent symptom-generating circuitry that mediates perceptual and cognitive disturbances of SZ and ultimately culminates in the onset of psychotic episodes.

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