Posterior fossa syndrome and increased mean diffusivity in the olivary bodies

2019 ◽  
Vol 24 (4) ◽  
pp. 376-381
Author(s):  
Derek Yecies ◽  
Rashad Jabarkheel ◽  
Michelle Han ◽  
Yong-Hun Kim ◽  
Lisa Bruckert ◽  
...  
Keyword(s):  
Posterior Fossa ◽  
Diffusion Tensor ◽  
Statistical Significance ◽  
Mean Diffusivity ◽  
Pediatric Brain Tumor ◽  
Structural Mri ◽  
Early Imaging ◽  
T2 Hyperintensity ◽  
The Right ◽  
Inferior Olivary

OBJECTIVEPosterior fossa syndrome (PFS) is a common postoperative complication following resection of posterior fossa tumors in children. It typically presents 1 to 2 days after surgery with mutism, ataxia, emotional lability, and other behavioral symptoms. Recent structural MRI studies have found an association between PFS and hypertrophic olivary degeneration, which is detectable as T2 hyperintensity in the inferior olivary nuclei (IONs) months after surgery. In this study, the authors investigated whether immediate postoperative diffusion tensor imaging (DTI) of the ION can serve as an early imaging marker of PFS.METHODSThe authors retrospectively reviewed pediatric brain tumor patients treated at their institution, Lucile Packard Children’s Hospital at Stanford, from 2004 to 2016. They compared the immediate postoperative DTI studies obtained in 6 medulloblastoma patients who developed PFS to those of 6 age-matched controls.RESULTSPatients with PFS had statistically significant increased mean diffusivity (MD) in the left ION (1085.17 ± 215.51 vs 860.17 ± 102.64, p = 0.044) and variably increased MD in the right ION (923.17 ± 119.2 vs 873.67 ± 60.16, p = 0.385) compared with age-matched controls. Patients with PFS had downward trending fractional anisotropy (FA) in both the left (0.28 ± 0.06 vs 0.23 ± 0.03, p = 0.085) and right (0.29 ± 0.06 vs 0.25 ± 0.02, p = 0.164) IONs compared with age-matched controls, although neither of these values reached statistical significance.CONCLUSIONSIncreased MD in the ION is associated with development of PFS. ION MD changes may represent an early imaging marker of PFS.

Selective Diffusion Changes of The Visual Pathways in Patients with Migraine: A 3-T Tractography Study

Cephalalgia ◽  
2008 ◽  
Vol 28 (10) ◽  
pp. 1061-1068 ◽  
Author(s):  
MA Rocca ◽  
E Pagani ◽  
B Colombo ◽  
P Tortorella ◽  
A Falini ◽  
...  
Keyword(s):  
Structural Changes ◽  
Corticospinal Tract ◽  
Diffusion Tensor ◽  
Clinical Manifestations ◽  
Mean Diffusivity ◽  
Structural Mri ◽  
Visual Aura ◽  
Selective Diffusion ◽  
Magnetic Resonance Imaging Mri ◽  
The Right

Using diffusion tensor (DT) tractography, we quantified optic radiation (OR) structural changes in seven migraine patients with (MA) and eight without visual aura (MoA) and their relation to clinical manifestations and T2-visible burden. The corticospinal tract and the corpus callosum were studied as ‘control’ white matter (WM). No difference was found for any of the WM fibre bundles metrics between controls and MoA patients. MA patients had reduced average fractional anisotropy (FA) of both OR compared with controls and reduced average FA of the right OR compared with MoA patients. They also showed higher right OR mean diffusivity than controls. OR metrics were not correlated with clinical and magnetic resonance imaging (MRI) metrics. DT tractography reveals OR changes in MA patients that might represent a phenotypic biomarker of the disease given the lack of correlation with clinical and structural MRI metrics.

Structural brain changes after 4 wk of unilateral strength training of the lower limb

2013 ◽  
Vol 115 (2) ◽  
pp. 167-175 ◽  
Author(s):  
H. S. Palmer ◽  
A. K. Håberg ◽  
M. S. Fimland ◽  
G. M. Solstad ◽  
V. Moe Iversen ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Strength Training ◽  
Isometric Contraction ◽  
Healthy Adult ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Cortical Activation ◽  
Maximum Voluntary Isometric Contraction ◽  
The Right ◽  
Unilateral Strength Training

Strength training enhances muscular strength and neural drive, but the underlying neuronal mechanisms remain unclear. This study used magnetic resonance imaging (MRI) to identify possible changes in corticospinal tract (CST) microstructure, cortical activation, and subcortical structure volumes following unilateral strength training of the plantar flexors. Mechanisms underlying cross-education of strength in the untrained leg were also investigated. Young, healthy adult volunteers were assigned to training ( n = 12) or control ( n = 9) groups. The 4 wk of training consisted of 16 sessions of 36 unilateral isometric plantar flexions. Maximum voluntary isometric contraction torque was tested pre- and posttraining. MRI investigation included a T1-weighted scan, diffusion tensor imaging and functional MRI. Probabilistic fiber tracking of the CST was performed on the diffusion tensor imaging images using a two-regions-of-interest approach. Fractional anisotropy and mean diffusivity were calculated for the left and right CST in each individual before and after training. Standard functional MRI analyses and volumetric analyses of subcortical structures were also performed. Maximum voluntary isometric contraction significantly increased in both the trained and untrained legs of the training group, but not the control group. A significant decrease in mean diffusivity was found in the left CST following strength training of the right leg. No significant changes were detected in the right CST. No significant changes in cortical activation were observed following training. A significant reduction in left putamen volume was found after training. This study provides the first evidence for strength training-related changes in white matter and putamen in the healthy adult brain.

scholarly journals Thalamic and thalamic projection abnormalities on DTI and NODDI analysis following acute concussion

Neurology ◽  
2019 ◽  
Vol 93 (14 Supplement 1) ◽  
pp. S4.2-S5
Author(s):  
James Houston ◽  
Frank Skidmore ◽  
William Monroe ◽  
Jon Amburgy ◽  
Mitchell Self
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Oculomotor System ◽  
White Matter Injury ◽  
Football Players ◽  
Cortical Regions ◽  
The Right ◽  
Collegiate Football ◽  
Concussive Injury

ObjectiveTo compare preseason and post-concussive MRI in a cohort of collegiate football players utilizing Diffusion Tensor Imaging (DTI) and Neurite Orientation Dispersion and Density Imaging (NODDI) post processing.BackgroundAcute post-concussive symptoms can vary in clinical characteristics and severity. However, vestibular and ocular dysfunction in particular, has been associated with poor clinical outcomes. The vestibular system comprises a complex network of projections from peripheral vestibular organs to thalamic relay systems and numerous cortical regions. The visual/oculomotor system is also complex, involving brainstem, subcortical-cortical and thalamo-cortical connections. Oculomotor deficits are thought to involve the midbrain and the visual and parietal association cortices, both of which have thalamic projections.Design/MethodsWe gathered pre-season MR diffusion weighted imaging on a cohort of 30 collegiate football players. We performed repeat imaging within 36 hours of any diagnosed concussion in the same subject cohort. DTI metrics: mean diffusivity (MD), axial diffusivity (AD), fractional anisotropy (FA), and radial diffusivity (RD) along with NODDI metric: orientation dispersion index (ODI), were analyzed for statistical comparisons between groups.Results4 subjects with pre-season MRI underwent repeat MRI within 36 hours of concussive injury. A paired t-test between these two groups using DTI and NODDI metrics showed significant (p < 0.05) decreases in: AD and MD in the left posterior thalamic radiations, FA in the column and body of the fornix, and MD in the right anterior corona radiata and superior fronto-occipital fasciculus, and a significant decrease in ODI in the anterior thalamus.ConclusionsDisruptions in the thalamus and its white matter projections may play a role in the vestibular/ocular dysfunction associated with acute concussive injury. While our numbers are small, the findings suggest that DTI and NODDI processing techniques have the capability to locate and measure grey and white matter injury patterns after concussive injury.

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.

Progressive alterations of perilesional brain tissue after Gamma Knife stereotactic radiosurgery: a diffusion tensor imaging study

2015 ◽  
Vol 3 (1-2) ◽  
Author(s):  
Herwin Speckter ◽  
José Bido ◽  
Giancarlo Hernandez ◽  
Diones Rivera ◽  
Luis Suazo ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
Brain Tissue ◽  
Gamma Knife ◽  
Time Course ◽  
Diffusion Tensor ◽  
Statistical Significance ◽  
Mean Diffusivity ◽  
Imaging Study ◽  
Vascular Lesion ◽  
Cerebral White Matter

AbstractTo search for microstructural lesions of normal-appearing cerebral white matter surrounding a tumor or a vascular lesion, after single-fraction stereotactic Gamma Knife (GK) radiosurgery.In 43 patients with different brain lesions, magnetic resonance including diffusion tensor imaging (DTI) was performed before and after GK radiosurgery and change of parameters was measured in areas surrounding the lesion.Outside the lesion, there was an increase in mean diffusivity (MD) and radial diffusivity (RD) between 2.1% and 3.4% in the 15–10 Gy and in the 10–5 Gy perilesional isodose volumes, which reached statistical significance (pairedWe report some minor, but nevertheless significant changes in DTI parameters in normal-appearing perilesional brain tissue after GK radiosurgery progressing with time, which partially may be induced by the radiation itself and partially may be due to indirect effects of lesion reactions to the radiation. Follow-up studies are necessary for further characterization of these changes and assessment of their time course.

scholarly journals Correlation between DTI effect and white matter structural integrity, working memory in leukoaraiosis patients

2021 ◽  
Vol 26 (3) ◽  
pp. 2714-2721
Author(s):  
XIAOFENG YANG ◽  
◽  
WANMENG XIE ◽  
Keyword(s):  
Working Memory ◽  
White Matter ◽  
Structural Integrity ◽  
Color Word ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Lesion Group ◽  
Cingulum Bundle ◽  
The Right ◽  
White Matter Area

Our objective was to study the correlation between Diffusion tensor MR imaging (DTI) effect and white matter structural integrity, working memory in leukoaraiosis patients. 100 leukoaraiosis patients referring to the First Affiliated Hospital of Beijing Medical University from December 2018 to December 2019, were selected as study subjects and divided into four groups according to disease severity: lesion-free group, mild lesion group, moderate lesion group, and severe lesion group. All patients underwent magnetic resonance diffusion tensor imaging to collect DWI images and analyze Fractional anisotropy (FA), mean diffusivity (MD), ReHo values of white matter area under different grading. The patients’ working memory was tested via auditory verb learning test and Stroop color word test, so that correlation between white matter structural integrity and working memory can be analyzed. Results: There are statistically significant differences in FA values of the right posterior thalamic radiation, the right sagittal layer and the right superior longitudinal fasciculus, MD values of the right sagittal layer, the right cingulum bundle, the left cingulum bundle, the right inferior fasciculus fronto-occipitalis and the left inferior fasciculus frontooccipitalis, as well as instant recall, delayed recall, delayed recognition, card A (dot), card B (character), card C (color word) and SIE value (P<0.01). Correlation is shown between white matter structural integrity and working memory, gender, age, grading, disease course, recurrence interval, white matter area, and testing methods. There was a correlation between DTI effect and white matter structural integrity, working memory in leukoaraiosis patients, and leukoaraiosis patients have memory impairment.

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.

White matter fiber microstructure is associated with prior hospitalizations rather than acute symptomatology in major depressive disorder

2020 ◽  
pp. 1-9
Author(s):  
Susanne Meinert ◽  
Elisabeth J. Leehr ◽  
Dominik Grotegerd ◽  
Jonathan Repple ◽  
Katharina Förster ◽  
...  
Keyword(s):  
Major Depressive Disorder ◽  
Depressive Disorder ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Cross Sectional Study ◽  
Disease State ◽  
Major Depressive ◽  
Cross Sectional ◽  
Course Of Illness ◽  
The Right

Abstract Background Eighty percent of all patients suffering from major depressive disorder (MDD) relapse at least once in their lifetime. Thus, understanding the neurobiological underpinnings of the course of MDD is of utmost importance. A detrimental course of illness in MDD was most consistently associated with superior longitudinal fasciculus (SLF) fiber integrity. As similar associations were, however, found between SLF fiber integrity and acute symptomatology, this study attempts to disentangle associations attributed to current depression from long-term course of illness. Methods A total of 531 patients suffering from acute (N = 250) or remitted (N = 281) MDD from the FOR2107-cohort were analyzed in this cross-sectional study using tract-based spatial statistics for diffusion tensor imaging. First, the effects of disease state (acute v. remitted), current symptom severity (BDI-score) and course of illness (number of hospitalizations) on fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity were analyzed separately. Second, disease state and BDI-scores were analyzed in conjunction with the number of hospitalizations to disentangle their effects. Results Disease state (pFWE < 0.042) and number of hospitalizations (pFWE< 0.032) were associated with decreased FA and increased MD and RD in the bilateral SLF. A trend was found for the BDI-score (pFWE > 0.067). When analyzed simultaneously only the effect of course of illness remained significant (pFWE < 0.040) mapping to the right SLF. Conclusions Decreased FA and increased MD and RD values in the SLF are associated with more hospitalizations when controlling for current psychopathology. SLF fiber integrity could reflect cumulative illness burden at a neurobiological level and should be targeted in future longitudinal analyses.

scholarly journals Neonatal Functional and Structural Connectivity Are Associated with Cerebral Palsy at Two Years of Age

2019 ◽  
Vol 37 (02) ◽  
pp. 137-145
Author(s):  
Stephanie L. Merhar ◽  
Elveda Gozdas ◽  
Jean A. Tkach ◽  
Nehal A. Parikh ◽  
Beth M. Kline-Fath ◽  
...  
Keyword(s):  
Cerebral Palsy ◽  
Brain Injury ◽  
Functional Connectivity ◽  
Diffusion Tensor ◽  
Structural Connectivity ◽  
Motor Task ◽  
Structural Mri ◽  
Perinatal Brain Injury ◽  
The Right ◽  
Almost All

Objective The accuracy of structural magnetic resonance imaging (MRI) to predict later cerebral palsy (CP) in newborns with perinatal brain injury is variable. Diffusion tensor imaging (DTI) and task-based functional MRI (fMRI) show promise as predictive tools. We hypothesized that infants who later developed CP would have reduced structural and functional connectivity as compared with those without CP. Study Design We performed DTI and fMRI using a passive motor task at 40 to 48 weeks' postmenstrual age in 12 infants with perinatal brain injury. CP was diagnosed at age 2 using a standardized examination. Results Five infants had CP at 2 years of age, and seven did not have CP. Tract-based spatial statistics showed a widespread reduction of fractional anisotropy (FA) in almost all white matter tracts in the CP group. Using the median FA value in the corticospinal tracts as a cutoff, FA was 100% sensitive and 86% specific to predict CP compared with a sensitivity of 60 to 80% and a specificity of 71% for structural MRI. During fMRI, the CP group had reduced functional connectivity from the right supplemental motor area as compared with the non-CP group. Conclusion DTI and fMRI obtained soon after birth are potential biomarkers to predict CP in newborns with perinatal brain injury.

scholarly journals T48. DEVIATIONS IN MICRO AND MACRO WHITE MATTER STRUCTURES IN PSYCHOSIS PRONENESS

2020 ◽  
Vol 46 (Supplement_1) ◽  
pp. S249-S250
Author(s):  
Seda Arslan ◽  
Tuba Şahin ◽  
Didenur Şahin ◽  
Timothea Toulopoulou
Keyword(s):  
White Matter ◽  
High Risk ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Structured Interview ◽  
Anterior Cingulate ◽  
White Matter Integrity ◽  
Psychosis Proneness ◽  
Brodmann Areas ◽  
The Right

Abstract Background Psychotic disorders are characterized by neurobiological deviations, including in the macro and microstructure of white matter. White matter alterations are also seen in psychosis-proneness and in individuals who have a high risk of psychosis. For example, studies have indicated decreases in white matter integrity in the genu/forceps minor of corpus callosum (CC) in the latter populations. Anterior corona radiata (ACR) is one crucial white-matter tract connecting the anterior cingulate cortex to the striatum. Indeed, reductions in the white matter structure of anterior genu of CC significantly predict the transition from ultra-high risk to psychosis. However, there is a gap in the literature related to observing the psychosis-proneness by applying both micro and macrostructural brain analyses, and most of the microstructural white matter studies in psychosis focus on fractional anisotropy (FA) and not include mean diffusivity (MD). Thus, the current study aims to assess whether white matter deviations in CG, ACR, and CC, are associated with psychosis proneness by combining both tract-based spatial statistics (TBSS) and voxel-based morphometry (VBM) analyses in a sample of participants with psychosis proneness (PP) and without psychosis proneness (NPP). Methods The study included 53 participants (29 PP vs. 24 NPP) whose ages were between 17 and 24 years. Participants were split into two groups based on their scores on Structured Interview for Schizotypy assessment, a well-validated instrument of psychosis proneness. White matter integrity was analyzed via diffusion tensor imaging (DTI) and white matter volume (WMV) via VBM. Two sample t-test was used in GLM for both DTI and VBM analyses. FA, MD, and VMV were compared between two groups to observe micro and macro white matter structure alterations in the region of interest. Results DTI analysis revealed decreased FA values in the right ACR and right genu of the CC in the psychosis-proneness group (F(1,52)= 7.37, p= 0.009). Moreover, VBM showed a significant WMV decreases in the right CG, Brodmann areas 8, 9, and 32 in the PP group (F(1,52)= 50.85, uncorrected p&lt;0.01). However, MD did not differ between the two groups (F(1,51)= 3.65, p=0.06) Discussion These findings suggest that PP associated with decreased white matter integrity in ACR, genu of CC, and also reduced white matter volumes in the right CG, Brodmann areas 8, 9, and 32. Significant FA decreases might result from alterations in radial or axial diffusivity since we did not observe significant MD differences between two groups. The current findings suggested that participants with PP had both macro and micro white matter structure disruptions, mostly in frontal parts of the right cerebrum, compared to no PP group.

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