Different neural substrates for executive functions in youths with ADHD: a diffusion spectrum imaging tractography study

2016 ◽  
Vol 46 (6) ◽  
pp. 1225-1238 ◽  
Author(s):  
H.-L. Chiang ◽  
Y.-J. Chen ◽  
C.-Y. Shang ◽  
W.-Y. I. Tseng ◽  
S. S.-F. Gau

BackgroundThe relationship between white-matter tracts and executive functions (EF) in attention deficit hyperactivity disorder (ADHD) has not been well studied and previous studies mainly focused on frontostriatal (FS) tracts. The authors explored the microstructural property of several fibre tracts hypothesized to be involved in EF, to correlate their microstructural property with EF, and to explore whether such associations differ between ADHD and typically developing (TD) youths.MethodWe assessed 45 youths with ADHD and 45 individually matched TD youths with a computerized test battery for multiple dimensions of EF. From magnetic resonance imaging, FS tract, superior longitudinal fasciculus (SLF), arcuate fasciculus (AF) and cingulum bundle (CB) were reconstructed by diffusion spectrum imaging tractography. The generalized fractional anisotropy (GFA) values of white-matter tracts were computed to present microstructural property of each tract.ResultsWe found lower GFA in the left FS tract, left SLF, left AF and right CB, and poorer performance in set-shifting, sustained attention, cognitive inhibition and visuospatial planning in ADHD than TD. The ADHD and TD groups demonstrated different association patterns between EF and fibre tract microstructural property. Most of the EF were associated with microstructural integrity of the FS tract and CB in TD youths, while with that of the FS tract, SLF and AF in youths with ADHD.ConclusionsOur findings support that the SLF, AF and CB also involve in a wide range of EF and that the main fibre tracts involved in EF are different in youths with ADHD.

2018 ◽  
Vol 103 (4) ◽  
pp. 511-516 ◽  
Author(s):  
Tzu-Hsun Tsai ◽  
Hsien-Te Su ◽  
Yung-Chin Hsu ◽  
Yao-Chia Shih ◽  
Chien-Chung Chen ◽  
...  

Background/aimWe investigated the microstructural changes in white matter of adults with amblyopia using diffusion spectrum imaging with systematic tract-based automatic analysis of the whole brain.MethodsTen adults with amblyopia (six women and four men, 33.6±10.6 years old on average) and 20 age- and sex-matched normal-sighted controls were enrolled. The mean generalised fractional anisotropy (GFA) was measured in 76 white matter tracts and compared between the experimental and control groups using a threshold-free cluster-weighted method and t-test. A 2-percentile cut-off was used to identify segments with the greatest differences between the two groups.ResultsParticipants with amblyopia had significantly lower GFA values than the controls in 11 segments located in nine white matter tracts, which included the following: left arcuate fasciculus, left frontal aslant tract, left fornix and left inferior fronto-occipital fasciculus of the association fibres; left thalamic radiations of the auditory nerve and bilateral optic radiations of the projection fibres; and genu and middle temporal gyrus of the callosal fibres. Amblyopic participants had statistically higher GFA values in the bilateral uncinate fasciculus than those of the controls.ConclusionThis preliminary study using whole-brain tractographic analysis of white matter reveals association between abnormal early visual processing and alterations in brain architecture, which may be related to various higher-level deficits, such as audiovisual integration and hand−eye coordination in patients with amblyopia.


2011 ◽  
Vol 23 (03) ◽  
pp. 215-222
Author(s):  
Yu-Chun Lo ◽  
Fu-Shan Jaw ◽  
Su-Chun Huang ◽  
Yu-Yang Yeh ◽  
Wen-Yih Isaac Tseng

Gender and handedness differences in cognitive functions and brain structures are well recognized. Recent research has reported different white matter structures between male and female subjects. Yet it is unknown whether the gender and handedness effects on different white matter tracts are comparable or disparate. In this study, we focus on three main tracts in the fronto-striato-thalamic circuit, namely, the cingulum bundles (CG), fornices (FXs) and anterior thalamic radiations (ATR). These are the primary connections among the frontal lobe, the limbic system, and the thalamus, integrating functions of emotion control, memory, and decision-making. A total of 40 healthy adults were recruited in this study. There was no significant difference in demographic variables between males and females. Images were acquired on a 3-T Magnetic resonance imaging (MRI) system with an eight-channel head coil. The diffusion spectrum imaging (DSI) experiment was performed by applying 203 diffusion gradient vectors. DSI maps the angular distribution of water molecule displacement by acquiring diffusion MR signals in a more comprehensive way. The theory of DSI is based on the Fourier transform relationship between diffusion MR signals and the average propagator of water molecule displacement. Isotropic spatial resolution was obtained by setting both in-plane and through-plane resolutions as 2.7 mm. A total of 45 trans-axial slices were acquired encompassing the whole brain. DSI analysis was computed based on the Fourier relationship between diffusion echo signals and the probability density function (PDF). Fiber tracking was used to define the targeted tracts. All fiber orientations of the nearest voxels were used to decide the proceeding orientation for the next step. Tracking stopped if there was no coinciding orientation in the nearest voxels. Mean path analysis, a method that projected the anisotropy of PDF [generalized fractional anisotropy (GFA)] onto a single mean path of the specific white matter tract bundle, was used to analyze subtle changes in microstructure coherence along individual tract bundles. The asymmetric differences of targeted tracts were assessed statistically by calculating GFA values and lateralization indices (LIs). The handedness factor of the LI values in CG and ATR showed a trend for significance. The gender factor of the LI values was investigated in FX also. Different white matter tract bundles manifested different degrees of gender effect on GFA distributions. Our results suggest that the gender and handedness factors should be considered when one evaluates the impairment of the fronto-striato-thalamic circuit.


2018 ◽  
Author(s):  
M. Justin Kim ◽  
Maxwell L. Elliott ◽  
Tracy C. d’Arbeloff ◽  
Annchen R. Knodt ◽  
Spenser R. Radtke ◽  
...  

AbstractAmongst a number of negative life sequelae associated with childhood adversity is the later expression of a higher dispositional tendency to experience anger and frustration to a wide range of situations (i.e., trait anger). We recently reported that an association between childhood adversity and trait anger is moderated by individual differences in both threat-related amygdala activity and executive control-related dorsolateral prefrontal cortex (dlPFC) activity, wherein individuals with relatively low amygdala and high dlPFC activity do not express higher trait anger even when having experienced childhood adversity. Here, we examine possible structural correlates of this functional dynamic using diffusion magnetic resonance imaging data from 647 young adult men and women volunteers. Specifically, we tested whether the degree of white matter microstructural integrity as indexed by fractional anisotropy modulated the association between childhood adversity and trait anger. Our analyses revealed that higher microstructural integrity of multiple pathways was associated with an attenuated link between childhood adversity and adult trait anger. Amongst these pathways was the uncinate fasciculus, which not only provides a major anatomical link between the amygdala and prefrontal cortex but also is associated with individual differences in regulating negative emotion through top-down cognitive reappraisal. These findings suggest that higher microstructural integrity of distributed white matter pathways including but not limited to the uncinate fasciculus may represent an anatomical foundation serving to buffer against the expression of childhood adversity as later trait anger, which is itself associated with multiple negative health outcomes.


2012 ◽  
Vol 34 (6) ◽  
pp. 1157-1163 ◽  
Author(s):  
C.R. McDonald ◽  
N.S. White ◽  
N. Farid ◽  
G. Lai ◽  
J.M. Kuperman ◽  
...  

Epilepsia ◽  
2013 ◽  
Vol 54 (10) ◽  
pp. 1801-1809 ◽  
Author(s):  
Chu-Yu Lee ◽  
Ali Tabesh ◽  
Andreana Benitez ◽  
Joseph A. Helpern ◽  
Jens H. Jensen ◽  
...  

2014 ◽  
Vol 45 (3) ◽  
pp. 529-543 ◽  
Author(s):  
S. S. Gau ◽  
W.-L. Tseng ◽  
W.-Y. I. Tseng ◽  
Y.-H. Wu ◽  
Y.-C. Lo

BackgroundDeficits in executive function (EF), impaired school functioning and altered white matter integrity in frontostriatal networks have been associated with attention-deficit/hyperactivity disorder (ADHD). However, relationships between impairments in these areas are unclear. Using a sample of youths with and without ADHD, this study examined the association between microstructural integrity of frontostriatal tracts and school dysfunction and the mediating roles of EF and ADHD symptoms in this association.MethodThe sample included 32 Taiwanese youths with ADHD and 32 age-, sex-, handedness- and IQ-matched typically-developing (TD) youths. Participants were assessed using psychiatric interviews, parent reports on ADHD symptoms and school functioning, and EF measures from the Cambridge Neuropsychological Test Automated Battery (CANTAB). The frontostriatal tracts were reconstructed by diffusion spectrum imaging (DSI) tractography and were subdivided into four functionally distinct segments: caudate–dorsolateral, caudate–medial prefrontal, caudate–orbitofrontal and caudate–ventrolateral tracts.ResultsYouths with ADHD, relative to TD youths, showed altered white matter integrity in all four bilateral pairs of frontostriatal tracts (decreased general fractional anisotropy, GFA), had poor attention, vigilance and response inhibition, and showed impaired school functioning. Altered microstructural integrity in frontostriatal tracts was significantly associated with school dysfunction, which was mediated by EF measures of attention/vigilance and response inhibition in addition to inattention and hyperactivity symptoms.ConclusionsOur findings demonstrate an association between white matter integrity in the frontostriatal networks and school functioning and suggest that EF deficits and ADHD symptoms may be the mediating mechanisms for this association. Future research is needed to test the directionality and specificity of this finding.


2019 ◽  
Vol 50 (7) ◽  
pp. 1203-1213 ◽  
Author(s):  
Huey-Ling Chiang ◽  
Yung-Chin Hsu ◽  
Chi-Yuan Shang ◽  
Wen-Yih Isaac Tseng ◽  
Susan Shur-Fen Gau

AbstractBackgroundBrain structural alterations are frequently observed in probands with attention-deficit/hyperactivity disorder (ADHD). Here we examined the microstructural integrity of 76 white matter tracts among unaffected siblings of patients with ADHD to evaluate the potential familial risk and its association with clinical and neuropsychological manifestations.MethodsThe comparison groups included medication-naïve ADHD probands (n = 50), their unaffected siblings (n = 50) and typically developing controls (n = 50, age-and-sex matched with ADHD probands). Whole brain tractography was reconstructed automatically by tract-based analysis of diffusion spectrum imaging (DSI). Microstructural properties of white matter tracts were represented by the values of generalized fractional anisotropy (GFA), fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD) and axial diffusivity (AD).ResultsCompared to the control group, ADHD probands showed higher AD values in the perpendicular fasciculus, superior longitudinal fasciculus I, corticospinal tract, and corpus callosum. The AD values of unaffected siblings were in the intermediate position between those of the ADHD and control groups. These AD values were significantly associated with ADHD symptoms, sustained attention and working memory, for all white matter tracks evaluated except for the perpendicular fasciculus. Higher FA and lower RD values in the right frontostriatal tract connecting ventrolateral prefrontal cortex (FS-VLPFC) were associated with better performance in spatial span only in the unaffected sibling group.ConclusionsAbnormal AD values of specific white matter tracts among unaffected siblings of ADHD probands suggest the presence of familial risk in this population. The right FS-VLPFC may have a role in preventing the expression of the ADHD-related behavioral phenotype.ClinicalTrials.gov numberNCT01682915


2010 ◽  
Vol 75 (1) ◽  
pp. e29-e36 ◽  
Author(s):  
Marzieh Nezamzadeh ◽  
Van J. Wedeen ◽  
Ruopeng Wang ◽  
Yu Zhang ◽  
Wang Zhan ◽  
...  

2021 ◽  
pp. 1-11
Author(s):  
Chuan Huang ◽  
Minos Kritikos ◽  
Sean A.P. Clouston ◽  
Yael Deri ◽  
Mario Serrano-Sosa ◽  
...  

Background: Individuals who participated in response efforts at the World Trade Center (WTC) following 9/11/2001 are experiencing elevated incidence of mild cognitive impairment (MCI) at midlife. Objective: We hypothesized that white matter connectivity measured using diffusion spectrum imaging (DSI) would be restructured in WTC responders with MCI versus cognitively unimpaired responders. Methods: Twenty responders (mean age 56; 10 MCI/10 unimpaired) recruited from an epidemiological study were characterized using NIA-AA criteria alongside controls matched on demographics (age/sex/occupation/race/education). Axial DSI was acquired on a 3T Siemen’s Biograph mMR scanner (12-channel head coil) using a multi-band diffusion sequence. Connectometry examined whole-brain tract-level differences in white matter integrity. Fractional anisotropy (FA), mean diffusivity (MD), and quantified anisotropy were extracted for region of interest (ROI) analyses using the Desikan-Killiany atlas. Results: Connectometry identified both increased and decreased connectivity within regions of the brains of responders with MCI identified in the corticothalamic pathway and cortico-striatal pathway that survived adjustment for multiple comparisons. MCI was also associated with higher FA values in five ROIs including in the rostral anterior cingulate; lower MD values in four ROIs including the left rostral anterior cingulate; and higher MD values in the right inferior circular insula. Analyses by cognitive domain revealed nominal associations in domains of response speed, verbal learning, verbal retention, and visuospatial learning. Conclusions: WTC responders with MCI at midlife showed early signs of neurodegeneration characterized by both increased and decreased white matter diffusivity in regions commonly affected by early-onset Alzheimer’s disease.


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