scholarly journals Variability in white matter structure relates to hallucination proneness

2021 ◽  
Author(s):  
Joseph F Johnson ◽  
Michael Schwartze ◽  
Michel Belyk ◽  
Ana P Pinheiro ◽  
Sonja A Kotz
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Clinical Care ◽  
Imaging Study ◽  
Healthy Individuals ◽  
Structural Variations ◽  
Psychosis Continuum ◽  
Increased Risk ◽  
Common Etiology ◽  
The Right

Hallucinations are a prominent transdiagnostic psychiatric symptom but are also prevalent in individuals who do not require clinical care. Moreover, persistent psychosis-like experience in otherwise healthy individuals may be related to increased risk to transition to a psychotic disorder. This suggests a common etiology across clinical and non-clinical individuals along a multidimensional psychosis continuum that may be detectable in structural variations of the brain. The current diffusion tensor imaging study assessed healthy individuals to identify possible differences in white matter associated with hallucination proneness (HP). This approach circumvents potential confounds related to medication, hospitalization, and disease progression common in clinical individuals. We determined how HP relates to white matter integrity in selected association, commissural, and projection fiber pathways putatively linked to psychosis. Increased HP was associated with enhanced fractional anisotropy (FA) in the right uncinate fasciculus, the right anterior and posterior arcuate fasciculus, and the corpus callosum. Although FA in cortico-cerebellar pathways revealed no relationship, streamline quantity between the left cerebellum and the right motor cortex positively correlated with HP. These findings support the notion of a psychosis continuum, providing first evidence of structural white matter variability associated with HP in healthy individuals. Furthermore, alterations in the targeted pathways likely indicate an association between HP-related structural variations and the putative salience and attention mechanisms that these pathways subserve.

Migraine affects white-matter tract integrity: A diffusion-tensor imaging study

Cephalalgia ◽  
2015 ◽  
Vol 35 (13) ◽  
pp. 1162-1171 ◽  
Author(s):  
Catherine D Chong ◽  
Todd J Schwedt
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Corticospinal Tract ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Imaging Study ◽  
White Matter Tract ◽  
Inferior Longitudinal Fasciculus ◽  
Left And Right ◽  
The Right

Background Specific white-matter tract alterations in migraine remain to be elucidated. Using diffusion tensor imaging (DTI), this study investigated whether the integrity of white-matter tracts that underlie regions of the “pain matrix” is altered in migraine and interrogated whether the number of years lived with migraine modifies fibertract structure. Methods Global probabilistic tractography was used to assess the anterior thalamic radiations, the corticospinal tracts and the inferior longitudinal fasciculi in 23 adults with migraine and 18 healthy controls. Results Migraine patients show greater mean diffusivity (MD) in the left and right anterior thalamic radiations, the left corticospinal tract, and the right inferior longitudinal fasciculus tract. Migraine patients also show greater radial diffusivity (RD) in the left anterior thalamic radiations, the left corticospinal tract as well as the left and right inferior longitudinal fasciculus tracts. No group fractional anisotropy (FA) differences were identified for any tracts. Migraineurs showed a positive correlation between years lived with migraine and MD in the right anterior thalamic radiations ( r = 0.517; p = 0.012) and the left corticospinal tract ( r = 0.468; p = 0.024). Conclusion Results indicate that white-matter integrity is altered in migraine and that longer migraine history is positively correlated with greater alterations in tract integrity.

scholarly journals A Diffusion Tensor Imaging Study on the Phonology-related Pathways in Cantonese-mandarin Bilinguals.

2021 ◽  
Author(s):  
Xiaoyu Xu ◽  
Yuying Jin ◽  
Ning Pan ◽  
Muqing Cao ◽  
Jin Jing ◽  
...  
Keyword(s):  
White Matter ◽  
Phonological Processing ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Imaging Study ◽  
Brain White Matter ◽  
The Mean ◽  
The Right ◽  
Long Term Experience

Abstract Cantonese and Mandarin are logographic languages, and the phonology is the main difference between the two languages. It is unclear whether long-term experience of Cantonese-Mandarin bilingualism will shape different brain white matter structures of pathways related to phonological processing. 30 Cantonese-Mandarin bilinguals and 30 Mandarin monolinguals completed diffusion-weighted imaging (DWI) scans and phonological processing tasks. The tractography and TBSS were used to investigate the structural differences in the bilateral superior longitudinal fasciculus (SLF), inferior longitudinal fasciculus (ILF) and inferior fronto-occipital fasciculus (IFOF) between Cantonese-Mandarin bilinguals and Mandarin monolinguals. Post-hoc correlation analysis was conducted to investigate the relationship between the different structures with phonological processing skills. Compared to the Mandarin monolinguals, the Cantonese-Mandarin bilinguals had higher fractional anisotropy (FA) along the left ILF, higher mean diffusivity (MD) in the clusters along the temporoparietal segment of SLF (tSLF), as well as higher axial diffusivity (AD) in the right tSLF, IFOF, bilateral ILF. The mean AD of the different voxels in the right IFOF and the mean FA of the different voxels in the left ILF were positively correlated with the inverse efficiency score (IES) of the Cantonese auditory and Mandarin visual rhyming judgment tasks respectively within the bilingual group. Long-term experience of Cantonese-Mandarin bilinguals shape different brain white matter structures including right tSLF, IFOF, bilateral ILF. The bilinguals’ white matter showed higher diffusivity, especially in the axonal direction, than the monolinguals. These changes were related to bilinguals’ phonological processing.

scholarly journals A Preliminary Diffusion Tensor Imaging Study: Analysis of Whole Brain according to the Affected Side in Tinnitus

2017 ◽  
Vol 5 (1-2) ◽  
pp. 1-12
Author(s):  
L. Shrestha
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Imaging Study ◽  
Healthy Controls ◽  
White Matter Changes ◽  
Whole Brain ◽  
Affected Side ◽  
The Right

Aim: To investigate the role of white matter integrity in the pathophysiology of tinnitus, and also to analyze the whole brain for white matter changes quantitatively by comparing tinnitus patients with healthy controls based on the affected side of the tinnitus using Tract Based Spatial Statistics (TBSS).Methods: Total of 41 right-handed tinnitus patients and 35 age-matched right-handed healthy controls were initially examined non-invasively in resting-state using the 3.0T MRI scanner. We obtained the estimated Fractional anisotropy (FA), mean diffusivity (MD), Axial Diffusivity (AD), Radial Diffusivity (RD), and Mode of Anisotropy (MO) data for each subject. TBSS was used to perform group statistical analysis of DTI data from each group.Results: Compared to controls in right-sided tinnitus patients, FA and MO were decreased, and MD was normal with decreased AD and increased RD. FA and AD showed similar decreased values (t>1.5, FWEcorrected P<0.05) in the right corticospinal tract, right superior longitudinal fasciculus, and right inferior fronto-occipital fasciculus. Compared to controls with left-sided tinnitus patients, FA and MO were decreased, and MD was also increased with decreased AD with increased RD in patients. MO showed significantly decreased values (t>1.5, FWEcorrected P<0.05) of MO in Forceps major, bilateral cingulum (especially the left), and bilateral anterior thalamic radiation. Bilaterally affected tinnitus patients showed no difference when compared to controls.Conclusion: After analyzing the whole brain for white matter changes quantitatively using TBSS, changes were observed in unilaterally affected tinnitus patients compared to controls. Our findings indicated cross-modal plasticity could have caused changes in somatosensory, audio-visual, limbic, and attention pathways.Nepal Journal of Radiology Vol.5(1-2) 2015: 1-12

Frontotemporal white-matter microstructural abnormalities in adolescents with conduct disorder: a diffusion tensor imaging study

2012 ◽  
Vol 43 (2) ◽  
pp. 401-411 ◽  
Author(s):  
S. Sarkar ◽  
M. C. Craig ◽  
M. Catani ◽  
F. Dell'Acqua ◽  
T. Fahy ◽  
...  
Keyword(s):  
White Matter ◽  
Conduct Disorder ◽  
Diffusion Tensor ◽  
Imaging Study ◽  
Group Differences ◽  
Violent Behaviour ◽  
Developmental Abnormalities ◽  
Age Related ◽  
Increased Risk ◽  
Mri Study

BackgroundChildren with conduct disorder (CD) are at increased risk of developing antisocial personality disorder (ASPD) and psychopathy in adulthood. The biological basis for this is poorly understood. A preliminary diffusion tensor magnetic resonance imaging (DT-MRI) study of psychopathic antisocial adults reported significant differences from controls in the fractional anisotropy (FA) of the uncinate fasciculus (UF), a white-matter tract that connects the amygdala to the frontal lobe. However, it is unknown whether developmental abnormalities are present in the UF of younger individuals with CD.MethodWe used DT-MRI tractography to investigate, for the first time, the microstructural integrity of the UF in adolescents with CD, and age-related differences in this tract. We compared FA and perpendicular diffusivity of the UF in 27 adolescents with CD and 16 healthy controls (12 to 19 years old) who did not differ significantly in age, IQ or substance use history. To confirm that these findings were specific to the UF, the same measurements were extracted from two non-limbic control tracts. Participants in the CD group had a history of serious aggressive and violent behaviour, including robbery, burglary, grievous bodily harm and sexual assault.ResultsIndividuals with CD had a significantly increased FA (p = 0.006), and reduced perpendicular diffusivity (p = 0.002), in the left UF. Furthermore, there were significant age-related between-group differences in perpendicular diffusivity of the same tract (Zobs = 2.40, p = 0.01). Controls, but not those with CD, showed significant age-related maturation. There were no significant between-group differences in any measure within the control tracts.ConclusionsAdolescents with CD have significant differences in the ‘connectivity’ and maturation of UF.

scholarly journals Comparison of cerebral blood flow and structural penumbras in relation to white matter hyperintensities: A multi-modal magnetic resonance imaging study

2016 ◽  
Vol 36 (9) ◽  
pp. 1528-1536 ◽  
Author(s):  
Nutta-on Promjunyakul ◽  
David L Lahna ◽  
Jeffrey A Kaye ◽  
Hiroko H Dodge ◽  
Deniz Erten-Lyons ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
White Matter ◽  
Structural Integrity ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Imaging Study ◽  
Normal Appearing White Matter ◽  
Increased Risk ◽  
Fluid Attenuated Inversion Recovery

Normal-appearing white matter (NAWM) surrounding WMHs is associated with decreased structural integrity and perfusion, increased risk of WMH growth, and is referred to as the WMH penumbra. Studies comparing structural and cerebral blood flow (CBF) penumbras within the same individuals are lacking, however, and would facilitate our understanding of mechanisms resulting in WM damage. This study aimed to compare both CBF and structural WMH penumbras in non-demented aging. Eighty-two elderly volunteers underwent 3T-MRI including fluid attenuated inversion recovery (FLAIR), pulsed arterial spin labeling and diffusion tensor imaging (DTI). A NAWM layer mask was generated for periventricular and deep WMHs. Mean CBF, DTI-fractional anisotropy (DTI-FA), DTI-mean diffusivity (DTI-MD) and FLAIR intensity for WMHs and its corresponding NAWM layer masks were computed and compared against its mean within total brain NAWM using mixed effects models. For both periventricular and deep WMHs, DTI-FA, DTI-MD and FLAIR intensity changes extended 2-9 mm surrounding WMHs (p ≤ 0.05), while CBF changes extended 13-14 mm (p ≤ 0.05). The CBF penumbra is more extensive than structural penumbras in relation to WMHs and includes WM tissue both with and without microstructural changes. Findings implicate CBF as a potential target for the prevention of both micro and macro structural WM damage.

scholarly journals Escitalopram Administration, Neuroplastic Effects and Relearning: A Diffusion Tensor Imaging Study in Healthy Individuals

2021 ◽  
Author(s):  
Thomas Vanicek ◽  
Murray Reed ◽  
Jakob Unterholzner ◽  
Manfred Kloebl ◽  
Godber Mathis Godbersen ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Imaging Study ◽  
Internal Capsule ◽  
Healthy Individuals ◽  
Resonance Imaging ◽  
Double Blind ◽  
White Matter Microstructure ◽  
Diffusion Tensor Imaging Study ◽  
Serotonergic Modulation

Background: Neuroplastic processes are influenced by selective serotonergic reuptake inhibitors, while learning in conjunction with the administration of serotonergic agents alters white matter microstructure in humans. The goal of this double-blind, placebo-controlled imaging study was to investigate the influence of escitalopram on white matter plasticity during (re)learning. Methods: Seventy-one healthy individuals (age = 25.6+/-5.0, 43 females) underwent 3 diffusion magnetic resonance imaging sessions: at baseline, after 3-weeks of associative learning (emotional/non-emotional content) and after relearning shuffled associations for an additional 3 weeks. During the relearning phase, subjects received daily escitalopram 10 mg or placebo orally. Data were analyzed using the FMRIB Software Library (FSL) and the implemented Tract-Based Spatial Statistics (TBSS) approach. Results: The TBSS analysis revealed widespread decreases in fractional anisotropy metrics in subjects that received escitalopram. In addition, axial diffusivity decreases were mainly found in the corpus callosum and in areas within the internal capsule. In subjects receiving placebo, we did not find such effects, nor did our results show diffusivity changes related to learning or relearning. Conclusion: Diffusivity changes were found within several tracts in the escitalopram group, while we observed no changes in the placebo group. Although previous studies examining the effects of SSRIs on white matter tracts in humans are underrepresented, our results suggest a relationship between serotonergic agents and diffusivity parameters. The findings of this study implicate that escitalopram may directly or indirectly impact white matter microstructures in healthy subjects. Nevertheless, we did not find a relationship between serotonergic modulation, neuroplastic effects and relearning.

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