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Sample records for white matter microstructural

  1. Longitudinal changes in microstructural white matter metrics in Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Chantel D. Mayo

    2017-01-01

    Conclusion: The current results indicate that sensitivity to white matter microstructure is a promising avenue for AD biomarker research. Additional longitudinal studies on both white and grey matter are warranted to further evaluate potential clinical utility.

  2. Mapping White Matter Microstructure in the One Month Human Brain.

    Science.gov (United States)

    Dean, D C; Planalp, E M; Wooten, W; Adluru, N; Kecskemeti, S R; Frye, C; Schmidt, C K; Schmidt, N L; Styner, M A; Goldsmith, H H; Davidson, R J; Alexander, A L

    2017-08-29

    White matter microstructure, essential for efficient and coordinated transmission of neural communications, undergoes pronounced development during the first years of life, while deviations to this neurodevelopmental trajectory likely result in alterations of brain connectivity relevant to behavior. Hence, systematic evaluation of white matter microstructure in the normative brain is critical for a neuroscientific approach to both typical and atypical early behavioral development. However, few studies have examined the infant brain in detail, particularly in infants under 3 months of age. Here, we utilize quantitative techniques of diffusion tensor imaging and neurite orientation dispersion and density imaging to investigate neonatal white matter microstructure in 104 infants. An optimized multiple b-value diffusion protocol was developed to allow for successful acquisition during non-sedated sleep. Associations between white matter microstructure measures and gestation corrected age, regional asymmetries, infant sex, as well as newborn growth measures were assessed. Results highlight changes of white matter microstructure during the earliest periods of development and demonstrate differential timing of developing regions and regional asymmetries. Our results contribute to a growing body of research investigating the neurobiological changes associated with neurodevelopment and suggest that characteristics of white matter microstructure are already underway in the weeks immediately following birth.

  3. Effects of white matter microstructure on phase and susceptibility maps.

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    Wharton, Samuel; Bowtell, Richard

    2015-03-01

    To investigate the effects on quantitative susceptibility mapping (QSM) and susceptibility tensor imaging (STI) of the frequency variation produced by the microstructure of white matter (WM). The frequency offsets in a WM tissue sample that are not explained by the effect of bulk isotropic or anisotropic magnetic susceptibility, but rather result from the local microstructure, were characterized for the first time. QSM and STI were then applied to simulated frequency maps that were calculated using a digitized whole-brain, WM model formed from anatomical and diffusion tensor imaging data acquired from a volunteer. In this model, the magnitudes of the frequency contributions due to anisotropy and microstructure were derived from the results of the tissue experiments. The simulations suggest that the frequency contribution of microstructure is much larger than that due to bulk effects of anisotropic magnetic susceptibility. In QSM, the microstructure contribution introduced artificial WM heterogeneity. For the STI processing, the microstructure contribution caused the susceptibility anisotropy to be significantly overestimated. Microstructure-related phase offsets in WM yield artifacts in the calculated susceptibility maps. If susceptibility mapping is to become a robust MRI technique, further research should be carried out to reduce the confounding effects of microstructure-related frequency contributions. © 2014 Wiley Periodicals, Inc.

  4. Abnormalities in white matter microstructure associated with chronic ketamine use.

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    Edward Roberts, R; Curran, H Valerie; Friston, Karl J; Morgan, Celia J A

    2014-01-01

    Ketamine is an N-methyl-D-aspartate (NMDA) receptor antagonist that has been found to induce schizophrenia-type symptoms in humans and is a potent and fast-acting antidepressant. It is also a relatively widespread drug of abuse, particularly in China and the UK. Acute administration has been well characterized, but the effect of extended periods of ketamine use-on brain structure in humans-remains poorly understood. We measured indices of white matter microstructural integrity and connectivity in the brain of 16 ketamine users and 16 poly-drug-using controls, and we used probabilistic tractography to quantify changes in corticosubcortical connectivity associated with ketamine use. We found a reduction in the axial diffusivity profile of white matter in a right hemisphere network of white matter regions in ketamine users compared with controls. Within the ketamine-user group, we found a significant positive association between the connectivity profile between the caudate nucleus and the lateral prefrontal cortex and dissociative experiences. These findings suggest that chronic ketamine use may be associated with widespread disruption of white matter integrity, and white matter pathways between subcortical and prefrontal cortical areas may in part predict individual differences in dissociative experiences due to ketamine use.

  5. White matter microstructural organization and gait stability in older adults

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    Sjoerd M. Bruijn

    2014-06-01

    Full Text Available Understanding age-related decline in gait stability and the role of alterations in brain structure is crucial. Here, we studied the relationship between white matter microstructural organization using Diffusion Tensor Imaging (DTI and advanced gait stability measures in 15 healthy young adults (range 18-30 years and 25 healthy older adults (range 62-82 years.Among the different gait stability measures, only stride time and the maximum Lyapunov exponent (which quantifies how well participants are able to attenuate small perturbations were found to decline with age. White matter microstructural organization (FA was lower throughout the brain in older adults. We found a strong correlation between FA in the left anterior thalamic radiation and left corticospinal tract on the one hand, and step width and safety margin (indicative of how close participants are to falling over on the other. These findings suggest that white matter FA in tracts connecting subcortical and prefrontal areas is associated with the implementation of an effective stabilization strategy during gait.

  6. Longitudinal changes in white matter microstructure after heavy cannabis use

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    Mary P. Becker

    2015-12-01

    Full Text Available Diffusion tensor imaging (DTI studies of cannabis users report alterations in brain white matter microstructure, primarily based on cross-sectional research, and etiology of the alterations remains unclear. We report findings from longitudinal voxelwise analyses of DTI data collected at baseline and at a 2-year follow-up on 23 young adult (18–20 years old at baseline regular cannabis users and 23 age-, sex-, and IQ-matched non-using controls with limited substance use histories. Onset of cannabis use was prior to age 17. Cannabis users displayed reduced longitudinal growth in fractional anisotropy in the central and parietal regions of the right and left superior longitudinal fasciculus, in white matter adjacent to the left superior frontal gyrus, in the left corticospinal tract, and in the right anterior thalamic radiation lateral to the genu of the corpus callosum, along with less longitudinal reduction of radial diffusion in the right central/posterior superior longitudinal fasciculus, corticospinal tract, and posterior cingulum. Greater amounts of cannabis use were correlated with reduced longitudinal growth in FA as was relatively impaired performance on a measure of verbal learning. These findings suggest that continued heavy cannabis use during adolescence and young adulthood alters ongoing development of white matter microstructure, contributing to functional impairment.

  7. Altered White Matter Microstructure in Children with Attention-Deficit/Hyperactivity Disorder

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    Nagel, Bonnie J.; Bathula, Deepti; Herting, Megan; Schmitt, Colleen; Kroenke, Christopher D.; Fair, Damien; Nigg, Joel T.

    2011-01-01

    Objective: Identification of biomarkers is a priority for attention-deficit/hyperactivity disorder (ADHD). Studies have documented macrostructural brain alterations in ADHD, but few have examined white matter microstructure, particularly in preadolescent children. Given dramatic white matter maturation across childhood, microstructural differences…

  8. Night sleep influences white matter microstructure in bipolar depression.

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    Benedetti, Francesco; Melloni, Elisa M T; Dallaspezia, Sara; Bollettini, Irene; Locatelli, Clara; Poletti, Sara; Colombo, Cristina

    2017-08-15

    Alteration of circadian rhythms and sleep disruption are prominent trait-like features of bipolar disorder (BD). Diffusion tensor imaging (DTI) measures suggest a widespread alteration of white matter (WM) microstructure in patients with BD. Sleep promotes myelination and oligodendrocyte precursor cells proliferation. We hypothesized a possible association between DTI measures of WM microstructure and sleep quantity measures in BD. We studied 69 inpatients affected by a depressive episode in course of type I BD. We used whole brain tract-based spatial statistics on DTI measures of WM microstructure: axial, radial, and mean diffusivity (AD, RD, MD), and fractional anisotropy (FA). Self-assessed measures of time asleep (TA) and total sleep time (TST) were extracted from the Pittsburgh Sleep Quality Index (PSQI). Actigraphic recordings were performed on a subsample of 23 patients. We observed a positive correlation of DTI measures of FA with actigraphic measures of TA and TST, and with PSQI measure of TA. DTI measures of RD inversely associated with actigraphic measure of TA, and with PSQI measures of TA and TST. Several WM tracts were involved, including corpus callosum, cyngulate gyrus, uncinate fasciculus, left superior and inferior longitudinal and fronto-occipital fasciculi, thalamic radiation, corona radiata, retrolenticular part of internal capsule and corticospinal tract. The study is correlational in nature, and no conclusion about a causal connection can be drawn. Reduced FA with increased RD and MD indicate higher water diffusivity associated with less organized myelin and/or axonal structures. Our findings suggest an association between sleep disruption and these measures of brain microstructure in specific tracts contributing to the functional connectivity in BD. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. White matter abnormalities of microstructure and physiological noise in schizophrenia

    OpenAIRE

    Cheng, Hu; Newman, Sharlene D.; Kent, Jerillyn S.; Bolbecker, Amanda; Klaunig, Mallory J.; O'Donnell, Brian F.; Puce, Aina; Hetrick, William P.

    2015-01-01

    White matter abnormalities in schizophrenia have been revealed by many imaging techniques and analysis methods. One of the findings by diffusion tensor imaging is a decrease in fractional anisotropy (FA), which is an indicator of white matter integrity. On the other hand, elevation of metabolic rate in white matter was observed from positron emission tomography (PET) studies. In this report, we aim to compare the two structural and functional effects on the same subjects. Our comparison is ba...

  10. White matter abnormalities of microstructure and physiological noise in schizophrenia.

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    Cheng, Hu; Newman, Sharlene D; Kent, Jerillyn S; Bolbecker, Amanda; Klaunig, Mallory J; O'Donnell, Brian F; Puce, Aina; Hetrick, William P

    2015-12-01

    White matter abnormalities in schizophrenia have been revealed by many imaging techniques and analysis methods. One of the findings by diffusion tensor imaging is a decrease in fractional anisotropy (FA), which is an indicator of white matter integrity. On the other hand, elevation of metabolic rate in white matter was observed from positron emission tomography (PET) studies. In this report, we aim to compare the two structural and functional effects on the same subjects. Our comparison is based on the hypothesis that signal fluctuation in white matter is associated with white matter functional activity. We examined the variance of the signal in resting state fMRI and found significant differences between individuals with schizophrenia and non-psychiatric controls specifically in white matter tissue. Controls showed higher temporal signal-to-noise ratios clustered in regions including temporal, frontal, and parietal lobes, cerebellum, corpus callosum, superior longitudinal fasciculus, and other major white matter tracts. These regions with higher temporal signal-to-noise ratio agree well with those showing higher metabolic activity reported by studies using PET. The results suggest that individuals with schizophrenia tend to have higher functional activity in white matter in certain brain regions relative to healthy controls. Despite some overlaps, the distinct regions for physiological noise are different from those for FA derived from diffusion tensor imaging, and therefore provide a unique angle to explore potential mechanisms to white matter abnormality.

  11. The dimensionality of between-person differences in white matter microstructure in old age.

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    Lövdén, Martin; Laukka, Erika Jonsson; Rieckmann, Anna; Kalpouzos, Grégoria; Li, Tie-Qiang; Jonsson, Tomas; Wahlund, Lars-Olof; Fratiglioni, Laura; Bäckman, Lars

    2013-06-01

    Between-person differences in white matter microstructure may partly generalize across the brain and partly play out differently for distinct tracts. We used diffusion-tensor imaging and structural equation modeling to investigate this issue in a sample of 260 adults aged 60-87 years. Mean fractional anisotropy and mean diffusivity of seven white matter tracts in each hemisphere were quantified. Results showed good fit of a model positing that individual differences in white matter microstructure are structured according to tracts. A general factor, although accounting for variance in the measures, did not adequately represent the individual differences. This indicates the presence of a substantial amount of tract-specific individual differences in white matter microstructure. In addition, individual differences are to a varying degree shared between tracts, indicating that general factors also affect white matter microstructure. Age-related differences in white matter microstructure were present for all tracts. Correlations among tract factors did not generally increase as a function of age, suggesting that aging is not a process with homogenous effects on white matter microstructure across the brain. These findings highlight the need for future research to examine whether relations between white matter microstructure and diverse outcomes are specific or general. Copyright © 2011 Wiley Periodicals, Inc.

  12. White matter microstructure mediates the relationship between cardiorespiratory fitness and spatial working memory in older adults

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    Oberlin, Lauren E.; Verstynen, Timothy D.; Burzynska, Agnieszka Z.; Voss, Michelle W.; Prakash, Ruchika Shaurya; Chaddock-Heyman, Laura; Wong, Chelsea; Fanning, Jason; Awick, Elizabeth; Gothe, Neha; Phillips, Siobhan M.; Mailey, Emily; Ehlers, Diane; Olson, Erin; Wojcicki, Thomas

    2015-01-01

    White matter structure declines with advancing age and has been associated with a decline in memory and executive processes in older adulthood. Yet, recent research suggests that higher physical activity and fitness levels may be associated with less white matter degeneration in late life, although the tract-specificity of this relationship is not well understood. In addition, these prior studies infrequently associate measures of white matter microstructure to cognitive outcomes, so the beha...

  13. White matter microstructure in transsexuals and controls investigated by diffusion tensor imaging

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    Kranz, Georg S; Hahn, Andreas; Kaufmann, Ulrike; Küblböck, Martin; Hummer, Allan; Ganger, Sebastian; Seiger, Rene; Winkler, Dietmar; Swaab, Dick F; Windischberger, Christian; Kasper, Siegfried; Lanzenberger, Rupert

    2014-01-01

    Biological causes underpinning the well known gender dimorphisms in human behavior, cognition, and emotion have received increased attention in recent years. The advent of diffusion-weighted magnetic resonance imaging has permitted the investigation of the white matter microstructure in

  14. White matter microstructure mediates the relationship between cardiorespiratory fitness and spatial working memory in older adults.

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    Oberlin, Lauren E; Verstynen, Timothy D; Burzynska, Agnieszka Z; Voss, Michelle W; Prakash, Ruchika Shaurya; Chaddock-Heyman, Laura; Wong, Chelsea; Fanning, Jason; Awick, Elizabeth; Gothe, Neha; Phillips, Siobhan M; Mailey, Emily; Ehlers, Diane; Olson, Erin; Wojcicki, Thomas; McAuley, Edward; Kramer, Arthur F; Erickson, Kirk I

    2016-05-01

    White matter structure declines with advancing age and has been associated with a decline in memory and executive processes in older adulthood. Yet, recent research suggests that higher physical activity and fitness levels may be associated with less white matter degeneration in late life, although the tract-specificity of this relationship is not well understood. In addition, these prior studies infrequently associate measures of white matter microstructure to cognitive outcomes, so the behavioral importance of higher levels of white matter microstructural organization with greater fitness levels remains a matter of speculation. Here we tested whether cardiorespiratory fitness (VO2max) levels were associated with white matter microstructure and whether this relationship constituted an indirect pathway between cardiorespiratory fitness and spatial working memory in two large, cognitively and neurologically healthy older adult samples. Diffusion tensor imaging was used to determine white matter microstructure in two separate groups: Experiment 1, N=113 (mean age=66.61) and Experiment 2, N=154 (mean age=65.66). Using a voxel-based regression approach, we found that higher VO2max was associated with higher fractional anisotropy (FA), a measure of white matter microstructure, in a diverse network of white matter tracts, including the anterior corona radiata, anterior internal capsule, fornix, cingulum, and corpus callosum (PFDR-correctedmicrostructure within these regions, among others, constituted a significant indirect path between VO2max and spatial working memory performance. These results suggest that greater aerobic fitness levels are associated with higher levels of white matter microstructural organization, which may, in turn, preserve spatial memory performance in older adulthood. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Microstructural White Matter Tissue Characteristics Are Modulated by Homocysteine: A Diffusion Tensor Imaging Study

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    Hsu, Jung-Lung; Chen, Wei-Hung; Bai, Chyi-Huey; Leu, Jyu-Gang; Hsu, Chien-Yeh; Viergever, Max A.; Leemans, Alexander

    2015-01-01

    Homocysteine level can lead to adverse effects on the brain white matter through endothelial dysfunction, microstructural inflammation, and neurotoxin effects. Despite previously observed associations between elevated homocysteine and macroscopic structural brain changes, it is still unknown whether microstructural associations of homocysteine on brain tissue properties can be observed in healthy subjects with routine MRI. To this end, we investigated potential relationships between homocyste...

  16. White matter microstructure alterations: a study of alcoholics with and without post-traumatic stress disorder.

    Directory of Open Access Journals (Sweden)

    Caitlin A Durkee

    Full Text Available Many brain imaging studies have demonstrated reductions in gray and white matter volumes in alcoholism, with fewer investigators using diffusion tensor imaging (DTI to examine the integrity of white matter pathways. Among various medical conditions, alcoholism and post-traumatic stress disorder (PTSD are two comorbid diseases that have similar degenerative effects on the white matter integrity. Therefore, understanding and differentiating these effects would be very important in characterizing alcoholism and PTSD. Alcoholics are known to have neurocognitive deficits in decision-making, particularly in decisions related to emotionally-motivated behavior, while individuals with PTSD have deficits in emotional regulation and enhanced fear response. It is widely believed that these types of abnormalities in both alcoholism and PTSD are related to fronto-limbic dysfunction. In addition, previous studies have shown cortico-limbic fiber degradation through fiber tracking in alcoholism. DTI was used to measure white matter fractional anisotropy (FA, which provides information about tissue microstructure, possibly indicating white matter integrity. We quantitatively investigated the microstructure of white matter through whole brain DTI analysis in healthy volunteers (HV and alcohol dependent subjects without PTSD (ALC and with PTSD (ALC+PTSD. These data show significant differences in FA between alcoholics and non-alcoholic HVs, with no significant differences in FA between ALC and ALC+PTSD in any white matter structure. We performed a post-hoc region of interest analysis that allowed us to incorporate multiple covariates into the analysis and found similar results. HV had higher FA in several areas implicated in the reward circuit, emotion, and executive functioning, suggesting that there may be microstructural abnormalities in white matter pathways that contribute to neurocognitive and executive functioning deficits observed in alcoholics. Furthermore

  17. Coupled changes in brain white matter microstructure and fluid intelligence in later life.

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    Ritchie, Stuart J; Bastin, Mark E; Tucker-Drob, Elliot M; Maniega, Susana Muñoz; Engelhardt, Laura E; Cox, Simon R; Royle, Natalie A; Gow, Alan J; Corley, Janie; Pattie, Alison; Taylor, Adele M; Valdés Hernández, Maria Del C; Starr, John M; Wardlaw, Joanna M; Deary, Ian J

    2015-06-03

    Understanding aging-related cognitive decline is of growing importance in aging societies, but relatively little is known about its neural substrates. Measures of white matter microstructure are known to correlate cross-sectionally with cognitive ability measures, but only a few small studies have tested for longitudinal relations among these variables. We tested whether there were coupled changes in brain white matter microstructure indexed by fractional anisotropy (FA) and three broad cognitive domains (fluid intelligence, processing speed, and memory) in a large cohort of human participants with longitudinal diffusion tensor MRI and detailed cognitive data taken at ages 73 years (n = 731) and 76 years (n = 488). Longitudinal changes in white matter microstructure were coupled with changes in fluid intelligence, but not with processing speed or memory. Individuals with higher baseline white matter FA showed less subsequent decline in processing speed. Our results provide evidence for a longitudinal link between changes in white matter microstructure and aging-related cognitive decline during the eighth decade of life. They are consistent with theoretical perspectives positing that a corticocortical "disconnection" partly explains cognitive aging. Copyright © 2015 Ritchie et al.

  18. Cigarette smoking is associated with reduced microstructural integrity of cerebral white matter.

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    Gons, Rob A R; van Norden, Anouk G W; de Laat, Karlijn F; van Oudheusden, Lucas J B; van Uden, Inge W M; Zwiers, Marcel P; Norris, David G; de Leeuw, Frank-Erik

    2011-07-01

    Cigarette smoking doubles the risk of dementia and Alzheimer's disease. Various pathophysiological pathways have been proposed to cause such a cognitive decline, but the exact mechanisms remain unclear. Smoking may affect the microstructural integrity of cerebral white matter. Diffusion tensor imaging is known to be sensitive for microstructural changes in cerebral white matter. We therefore cross-sectionally studied the relation between smoking behaviour (never, former, current) and diffusion tensor imaging parameters in both normal-appearing white matter and white matter lesions as well as the relation between smoking behaviour and cognitive performance. A structured questionnaire was used to ascertain the amount and duration of smoking in 503 subjects with small-vessel disease, aged between 50 and 85 years. Cognitive function was assessed with a neuropsychological test battery. All subjects underwent 1.5 Tesla magnetic resonance imaging. Using diffusion tensor imaging, fractional anisotropy and mean diffusivity were calculated in both normal-appearing white matter and white matter lesions. A history of smoking was associated with significant higher values of mean diffusivity in normal-appearing white matter and white matter lesions (P-trend for smoking status = 0.02) and with poorer cognitive functioning compared with those who never smoked. Associations with smoking and loss of structural integrity appeared to be strongest in normal-appearing white matter. Furthermore, the duration of smoking cessation was positively related to lower values of mean diffusivity and higher values of fractional anisotropy in normal-appearing white matter [β = -0.004 (95% confidence interval -0.007 to 0.000; P = 0.03) and β = 0.019 (95% confidence interval 0.001-0.038; P = 0.04)]. Fractional anisotropy and mean diffusivity values in normal-appearing white matter of subjects who had quit smoking for >20 years were comparable with subjects who had never smoked. These data suggest

  19. Probing white-matter microstructure with higher-order diffusion tensors and susceptibility tensor MRI

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    Liu, Chunlei; Murphy, Nicole E.; Li, Wei

    2012-01-01

    Diffusion MRI has become an invaluable tool for studying white matter microstructure and brain connectivity. The emergence of quantitative susceptibility mapping and susceptibility tensor imaging (STI) has provided another unique tool for assessing the structure of white matter. In the highly ordered white matter structure, diffusion MRI measures hindered water mobility induced by various tissue and cell membranes, while susceptibility sensitizes to the molecular composition and axonal arrangement. Integrating these two methods may produce new insights into the complex physiology of white matter. In this study, we investigated the relationship between diffusion and magnetic susceptibility in the white matter. Experiments were conducted on phantoms and human brains in vivo. Diffusion properties were quantified with the diffusion tensor model and also with the higher order tensor model based on the cumulant expansion. Frequency shift and susceptibility tensor were measured with quantitative susceptibility mapping and susceptibility tensor imaging. These diffusion and susceptibility quantities were compared and correlated in regions of single fiber bundles and regions of multiple fiber orientations. Relationships were established with similarities and differences identified. It is believed that diffusion MRI and susceptibility MRI provide complementary information of the microstructure of white matter. Together, they allow a more complete assessment of healthy and diseased brains. PMID:23507987

  20. Unaffected twins discordant for affective disorders show changes in anterior callosal white matter microstructure

    DEFF Research Database (Denmark)

    Macoveanu, J; Vinberg, M; Madsen, K.

    2016-01-01

    OBJECTIVE: The neurobiological mechanisms mediating an increased risk to develop affective disorders remain poorly understood. In a group of individuals with a family history of major depressive (MDD) or bipolar disorder (BD), we investigated the microstructural properties of white matter fiber...

  1. White matter microstructure and developmental improvement of hyperactive/impulsive symptoms in Attention-Deficit/Hyperactivity

    NARCIS (Netherlands)

    Francx, W.; Zwiers, M.P.; Mennes, M.; Oosterlaan, J.; Heslenfeld, D.J.; Hoekstra, P.; Hartman, C.A.; Franke, C.; Faraone, S.V.; O'Dwyer, L.; Buitelaar, J.K.

    2015-01-01

    Background A developmental improvement of symptoms in attention-deficit/hyperactivity disorder (ADHD) is frequently reported, but the underlying neurobiological substrate has not been identified. The aim of this study was to determine whether white matter microstructure is related to developmental

  2. White matter microstructure damage in tremor-dominant Parkinson's disease patients

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    Luo, ChunYan; Song, Wei; Chen, Qin; Yang, Jing; Shang, Hui-Fang; Gong, QiYong

    2017-01-01

    Resting tremor is one of the cardinal motor features of Parkinson's disease (PD). Several lines of evidence suggest resting tremor may have different underlying pathophysiological processes from those of bradykinesia and rigidity. The current study aims to identify white matter microstructural abnormalities associated with resting tremor in PD. We recruited 60 patients with PD (30 with tremor-dominant PD and 30 with nontremor-dominant PD) and 26 normal controls. All participants underwent clinical assessment and diffusion tensor MRI. We used tract-based spatial statistics to investigate white matter integrity across the entire white matter tract skeleton. Compared with both healthy controls and the nontremor-dominant PD patients, the tremor-dominant PD patients were characterized by increased mean diffusivity (MD) and axial diffusivity (AD) along multiple white matter tracts, mainly involving the cerebello-thalamo-cortical (CTC) pathway. The mean AD value in clusters with significant difference was correlated with resting tremor score in the tremor-dominant PD patients. There was no significant difference between the nontremor-dominant PD patients and controls. Our results support the notion that resting tremor in PD is a distinct condition in which significant microstructural white matter changes exist and provide evidence for the involvement of the CTC in tremor genesis of PD. (orig.)

  3. White matter microstructure damage in tremor-dominant Parkinson's disease patients

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    Luo, ChunYan; Song, Wei; Chen, Qin; Yang, Jing; Shang, Hui-Fang [Sichuan University, Department of Neurology, West China Hospital, Chengdu, Sichuan (China); Gong, QiYong [Sichuan University, Huaxi MR Research Center, Department of Radiology, West China Hospital, Chengdu, Sichuan (China)

    2017-07-15

    Resting tremor is one of the cardinal motor features of Parkinson's disease (PD). Several lines of evidence suggest resting tremor may have different underlying pathophysiological processes from those of bradykinesia and rigidity. The current study aims to identify white matter microstructural abnormalities associated with resting tremor in PD. We recruited 60 patients with PD (30 with tremor-dominant PD and 30 with nontremor-dominant PD) and 26 normal controls. All participants underwent clinical assessment and diffusion tensor MRI. We used tract-based spatial statistics to investigate white matter integrity across the entire white matter tract skeleton. Compared with both healthy controls and the nontremor-dominant PD patients, the tremor-dominant PD patients were characterized by increased mean diffusivity (MD) and axial diffusivity (AD) along multiple white matter tracts, mainly involving the cerebello-thalamo-cortical (CTC) pathway. The mean AD value in clusters with significant difference was correlated with resting tremor score in the tremor-dominant PD patients. There was no significant difference between the nontremor-dominant PD patients and controls. Our results support the notion that resting tremor in PD is a distinct condition in which significant microstructural white matter changes exist and provide evidence for the involvement of the CTC in tremor genesis of PD. (orig.)

  4. Prenatal exposure to maternal and paternal depressive symptoms and white matter microstructure in children.

    Science.gov (United States)

    El Marroun, Hanan; Zou, Runyu; Muetzel, Ryan L; Jaddoe, Vincent W; Verhulst, Frank C; White, Tonya; Tiemeier, Henning

    2018-04-01

    Prenatal maternal depression has been associated with multiple problems in offspring involving affect, cognition, and neuroendocrine functioning. This suggests that prenatal depression influences neurodevelopment. However, the underlying neurodevelopmental mechanism remains unclear. We prospectively assessed whether maternal depressive symptoms during pregnancy and at the child's age 3 years are related to white matter microstructure in 690 children. The association of paternal depressive symptoms with childhood white matter microstructure was assessed to evaluate genetic or familial confounding. Parental depressive symptoms were measured using the Brief Symptom Inventory. In children aged 6-9 years, we used diffusion tensor imaging to assess white matter microstructure characteristics including fractional anisotropy (FA) and mean diffusivity (MD). Exposure to maternal depressive symptoms during pregnancy was associated with higher MD in the uncinate fasciculus and to lower FA and higher MD in the cingulum bundle. No associations of maternal depressive symptoms at the child's age of 3 years with white matter characteristics were observed. Paternal depressive symptoms also showed a trend toward significance for a lower FA in the cingulum bundle. Prenatal maternal depressive symptoms were associated with higher MD in the uncinate fasciculus and the cingulum bundle. These structures are part of the limbic system, which is involved in motivation, emotion, learning, and memory. As paternal depressive symptoms were also related to lower FA in the cingulum, the observed effect may partly reflect a genetic predisposition and shared environmental family factors and to a lesser extent a specific intrauterine effect. © 2018 Wiley Periodicals, Inc.

  5. Intra-individual variability in information processing speed reflects white matter microstructure in multiple sclerosis.

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    Mazerolle, Erin L; Wojtowicz, Magdalena A; Omisade, Antonina; Fisk, John D

    2013-01-01

    Slowed information processing speed is commonly reported in persons with multiple sclerosis (MS), and is typically investigated using clinical neuropsychological tests, which provide sensitive indices of mean-level information processing speed. However, recent studies have demonstrated that within-person variability or intra-individual variability (IIV) in information processing speed may be a more sensitive indicator of neurologic status than mean-level performance on clinical tests. We evaluated the neural basis of increased IIV in mildly affected relapsing-remitting MS patients by characterizing the relation between IIV (controlling for mean-level performance) and white matter integrity using diffusion tensor imaging (DTI). Twenty women with relapsing-remitting MS and 20 matched control participants completed the Computerized Test of Information Processing (CTIP), from which both mean response time and IIV were calculated. Other clinical measures of information processing speed were also collected. Relations between IIV on the CTIP and DTI metrics of white matter microstructure were evaluated using tract-based spatial statistics. We observed slower and more variable responses on the CTIP in MS patients relative to controls. Significant relations between white matter microstructure and IIV were observed for MS patients. Increased IIV was associated with reduced integrity in more white matter tracts than was slowed information processing speed as measured by either mean CTIP response time or other neuropsychological test scores. Thus, despite the common use of mean-level performance as an index of cognitive dysfunction in MS, IIV may be more sensitive to the overall burden of white matter disease at the microstructural level. Furthermore, our study highlights the potential value of considering within-person fluctuations, in addition to mean-level performance, for uncovering brain-behavior relationships in neurologic disorders with widespread white matter pathology.

  6. Experience-dependent plasticity in white matter microstructure: Reasoning training alters structural connectivity

    Directory of Open Access Journals (Sweden)

    Allyson P Mackey

    2012-08-01

    Full Text Available Diffusion tensor imaging (DTI techniques have made it possible to investigate white matter plasticity in humans. Changes in DTI measures, principally increases in fractional anisotropy (FA, have been observed following training programs as diverse as juggling, meditation, and working memory. Here, we sought to test whether three months of reasoning training could alter white matter microstructure. We recruited participants (n=23 who were enrolled in a course to prepare for the Law School Admission Test (LSAT, a test that places strong demands on reasoning skills, as well as age- and IQ-matched controls planning to take the LSAT in the future (n=22. DTI data were collected at two scan sessions scheduled three months apart. In trained participants but not controls, we observed decreases in radial diffusivity (RD in white matter connecting frontal cortices, and in mean diffusivity (MD within frontal and parietal lobe white matter. Further, participants exhibiting larger gains on the LSAT exhibited greater decreases in MD in the right internal capsule. In summary, reasoning training altered multiple measures of white matter structure in young adults. While the cellular underpinnings are unknown, these results provide evidence of experience-dependent white matter changes that may not be limited to myelination.

  7. White matter microstructure and cognitive decline in metabolic syndrome: a review of diffusion tensor imaging.

    Science.gov (United States)

    Alfaro, Freddy J; Gavrieli, Anna; Saade-Lemus, Patricia; Lioutas, Vasileios-Arsenios; Upadhyay, Jagriti; Novak, Vera

    2018-01-01

    Metabolic syndrome is a cluster of cardiovascular risk factors defined by the presence of abdominal obesity, glucose intolerance, hypertension and/or dyslipidemia. It is a major public health epidemic worldwide, and a known risk factor for the development of cognitive dysfunction and dementia. Several studies have demonstrated a positive association between the presence of metabolic syndrome and worse cognitive outcomes, however, evidence of brain structure pathology is limited. Diffusion tensor imaging has offered new opportunities to detect microstructural white matter changes in metabolic syndrome, and a possibility to detect associations between functional and structural abnormalities. This review analyzes the impact of metabolic syndrome on white matter microstructural integrity, brain structure abnormalities and their relationship to cognitive function. Each of the metabolic syndrome components exerts a specific signature of white matter microstructural abnormalities. Metabolic syndrome and its components exert both additive/synergistic, as well as, independent effects on brain microstructure thus accelerating brain aging and cognitive decline. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Microstructural abnormalities in white and gray matter in obese adolescents with and without type 2 diabetes

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    Arie Nouwen

    Full Text Available Aims/hypotheses: In adults, type 2 diabetes and obesity have been associated with structural brain changes, even in the absence of dementia. Some evidence suggested similar changes in adolescents with type 2 diabetes but comparisons with a non-obese control group have been lacking. The aim of the current study was to examine differences in microstructure of gray and white matter between adolescents with type 2 diabetes, obese adolescents and healthy weight adolescents. Methods: Magnetic resonance imaging data were collected from 15 adolescents with type 2 diabetes, 21 obese adolescents and 22 healthy weight controls. Volumetric differences in the gray matter between the three groups were examined using voxel based morphology, while tract based spatial statistics was used to examine differences in the microstructure of the white matter. Results: Adolescents with type 2 diabetes and obese adolescents had reduced gray matter volume in the right hippocampus, left putamen and caudate, bilateral amygdala and left thalamus compared to healthy weight controls. Type 2 diabetes was also associated with significant regional changes in fractional anisotropy within the corpus callosum, fornix, left inferior fronto-occipital fasciculus, left uncinate, left internal and external capsule. Fractional anisotropy reductions within these tracts were explained by increased radial diffusivity, which may suggest demyelination of white matter tracts. Mean diffusivity and axial diffusivity did not differ between the groups. Conclusion/interpretation: Our data shows that adolescent obesity alone results in reduced gray matter volume and that adolescent type 2 diabetes is associated with both white and gray matter abnormalities. Keywords: Type 2 diabetes, Obesity, White matter, Gray matter, Demyelination

  9. Widespread changes in white matter microstructure after a day of waking and sleep deprivation.

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    Torbjørn Elvsåshagen

    Full Text Available Elucidating the neurobiological effects of sleep and waking remains an important goal of the neurosciences. Recently, animal studies indicated that sleep is important for cell membrane and myelin maintenance in the brain and that these structures are particularly susceptible to insufficient sleep. Here, we tested the hypothesis that a day of waking and sleep deprivation would be associated with changes in diffusion tensor imaging (DTI indices of white matter microstructure sensitive to axonal membrane and myelin alterations.Twenty-one healthy adult males underwent DTI in the morning [7:30AM; time point (TP1], after 14 hours of waking (TP2, and then after another 9 hours of waking (TP3. Whole brain voxel-wise analysis was performed with tract based spatial statistics.A day of waking was associated with widespread increases in white matter fractional anisotropy, which were mainly driven by radial diffusivity reductions, and sleep deprivation was associated with widespread fractional anisotropy decreases, which were mainly explained by reductions in axial diffusivity. In addition, larger decreases in axial diffusivity after sleep deprivation were associated with greater sleepiness. All DTI changes remained significant after adjusting for hydration measures.This is the first DTI study of sleep deprivation in humans. Although previous studies have observed localized changes in DTI indices of cerebral microstructure over the course of a few hours, further studies are needed to confirm widespread DTI changes within hours of waking and to clarify whether such changes in white matter microstructure serve as neurobiological substrates of sleepiness.

  10. Simultaneous Assessment of White Matter Changes in Microstructure and Connectedness in the Blind Brain

    Directory of Open Access Journals (Sweden)

    Nina Linde Reislev

    2016-01-01

    Full Text Available Magnetic resonance imaging (MRI of the human brain has provided converging evidence that visual deprivation induces regional changes in white matter (WM microstructure. It remains unclear how these changes modify network connections between brain regions. Here we used diffusion-weighted MRI to relate differences in microstructure and structural connectedness of WM in individuals with congenital or late-onset blindness relative to normally sighted controls. Diffusion tensor imaging (DTI provided voxel-specific microstructural features of the tissue, while anatomical connectivity mapping (ACM assessed the connectedness of each voxel with the rest of the brain. ACM yielded reduced anatomical connectivity in the corpus callosum in individuals with congenital but not late-onset blindness. ACM did not identify any brain region where blindness resulted in increased anatomical connectivity. DTI revealed widespread microstructural differences as indexed by a reduced regional fractional anisotropy (FA. Blind individuals showed lower FA in the primary visual and the ventral visual processing stream relative to sighted controls regardless of the blindness onset. The results show that visual deprivation shapes WM microstructure and anatomical connectivity, but these changes appear to be spatially dissociated as changes emerge in different WM tracts. They also indicate that regional differences in anatomical connectivity depend on the onset of blindness.

  11. White-matter microstructure and hearing acuity in older adults: a population-based cross-sectional DTI study.

    Science.gov (United States)

    Rigters, Stephanie C; Cremers, Lotte G M; Ikram, M Arfan; van der Schroeff, Marc P; de Groot, Marius; Roshchupkin, Gennady V; Niessen, Wiro J N; Baatenburg de Jong, Robert J; Goedegebure, André; Vernooij, Meike W

    2018-01-01

    To study the relation between the microstructure of white matter in the brain and hearing function in older adults we carried out a population-based, cross-sectional study. In 2562 participants of the Rotterdam Study, we conducted diffusion tensor imaging to determine the microstructure of the white-matter tracts. We performed pure-tone audiogram and digit-in-noise tests to quantify hearing acuity. Poorer white-matter microstructure, especially in the association tracts, was related to poorer hearing acuity. After differentiating the separate white-matter tracts in the left and right hemisphere, poorer white-matter microstructure in the right superior longitudinal fasciculus and the right uncinate fasciculus remained significantly associated with worse hearing. These associations did not significantly differ between middle-aged (51-69 years old) and older (70-100 years old) participants. Progressing age was thus not found to be an effect modifier. In a voxel-based analysis no voxels in the white matter were significantly associated with hearing impairment. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Simultaneous Assessment of White Matter Changes in Microstructure and Connectedness in the Blind Brain

    DEFF Research Database (Denmark)

    Reislev, Nina Linde; Dyrby, Tim Bjørn; Siebner, Hartwig Roman

    2016-01-01

    Magnetic resonance imaging (MRI) of the human brain has provided converging evidence that visual deprivation induces regional changes in white matter (WM) microstructure. It remains unclear how these changes modify network connections between brain regions. Here we used diffusion-weighted MRI......) assessed the connectedness of each voxel with the rest of the brain. ACM yielded reduced anatomical connectivity in the corpus callosum in individuals with congenital but not late-onset blindness. ACM did not identify any brain region where blindness resulted in increased anatomical connectivity. DTI...... revealed widespread microstructural differences as indexed by a reduced regional fractional anisotropy (FA). Blind individuals showed lower FA in the primary visual and the ventral visual processing stream relative to sighted controls regardless of the blindness onset. The results show that visual...

  13. White matter microstructure changes induced by motor skill learning utilizing a body machine interface.

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    Wang, Xue; Casadio, Maura; Weber, Kenneth A; Mussa-Ivaldi, Ferdinando A; Parrish, Todd B

    2014-03-01

    The purpose of this study is to identify white matter microstructure changes following bilateral upper extremity motor skill training to increase our understanding of learning-induced structural plasticity and enhance clinical strategies in physical rehabilitation. Eleven healthy subjects performed two visuo-spatial motor training tasks over 9 sessions (2-3 sessions per week). Subjects controlled a cursor with bilateral simultaneous movements of the shoulders and upper arms using a body machine interface. Before the start and within 2days of the completion of training, whole brain diffusion tensor MR imaging data were acquired. Motor training increased fractional anisotropy (FA) values in the posterior and anterior limbs of the internal capsule, the corona radiata, and the body of the corpus callosum by 4.19% on average indicating white matter microstructure changes induced by activity-dependent modulation of axon number, axon diameter, or myelin thickness. These changes may underlie the functional reorganization associated with motor skill learning. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Impact of early and recent stress on white matter microstructure in major depressive disorder.

    Science.gov (United States)

    Poletti, Sara; Aggio, Veronica; Brioschi, Silvia; Bollettini, Irene; Falini, Andrea; Colombo, Cristina; Benedetti, Francesco

    2018-01-01

    Major Depressive Disorder (MDD) is a worldwide-spread pathology, characterized by lifetime-recurrent episodes. Adverse childhood experiences (ACE) increase the lifetime risk of developing depression and affect the structure of the brain. Recent stressful events (RSE) can trigger the onset of depressive episodes, and affect grey matter volume. The aim of our study is to analyse the effect of both early and recent stress events on white matter microstructure in MDD patients and healthy volunteers. Sixty-five MDD inpatients and fifty-nine healthy controls underwent MRI acquisition of diffusion tensor images with a 3.0T scanner. Severity of ACE and RSE was rated, respectively, on the Risky Families Questionnaire and on the Social Readjustment Rating Scale. A significant effect of diagnosis was observed, with MDD subjects showing reduced fractional anisotropy (FA) and axial diffusivity (AD) compared to healthy controls in all the major association, projection and commissural tracts. In patients with MDD, but not in healthy controls, both ACE and RSE correlated with measures of WM microstructure: ACE correlated negatively with AD and MD, whereas RSE correlated negatively with FA. The two diagnostic groups differed for age and education, previous and current medications, and treatment periods. Exposure to both early and recent stress exerts a widespread effect on WM microstructure of MDD patients, with a different impact possibly depending from the developmental period in which the stress has occurred. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Functional connectivity and microstructural white matter changes in phenocopy frontotemporal dementia

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    Meijboom, R.; Steketee, R.M.E.; Lugt, A. van der; Smits, M. [Erasmus MC - University Medical Centre, Radiology and Nuclear Medicine, Rotterdam (Netherlands); Koning, I. de [Erasmus MC - University Medical Centre, Neuropsychology, Rotterdam (Netherlands); Osse, R.J. [Erasmus MC - University Medical Centre, Psychiatry, Rotterdam (Netherlands); Jiskoot, L.C. [Erasmus MC - University Medical Centre, Neuropsychology, Rotterdam (Netherlands); Erasmus MC - University Medical Centre, Neurology, Rotterdam (Netherlands); Jong, F.J. de; Swieten, J.C. van [Erasmus MC - University Medical Centre, Neurology, Rotterdam (Netherlands)

    2017-04-15

    Phenocopy frontotemporal dementia (phFTD) is a rare and poorly understood clinical syndrome. PhFTD shows core behavioural variant FTD (bvFTD) symptoms without associated cognitive deficits and brain abnormalities on conventional MRI and without progression. In contrast to phFTD, functional connectivity and white matter (WM) microstructural abnormalities have been observed in bvFTD. We hypothesise that phFTD belongs to the same disease spectrum as bvFTD and investigated whether functional connectivity and microstructural WM changes similar to bvFTD are present in phFTD. Seven phFTD patients without progression or alternative psychiatric diagnosis, 12 bvFTD patients and 17 controls underwent resting state functional MRI (rs-fMRI) and diffusion tensor imaging (DTI). Default mode network (DMN) connectivity and WM measures were compared between groups. PhFTD showed subtly increased DMN connectivity and subtle microstructural changes in frontal WM tracts. BvFTD showed abnormalities in similar regions as phFTD, but had lower increased DMN connectivity and more extensive microstructural WM changes. Our findings can be interpreted as neuropathological changes in phFTD and are in support of the hypothesis that phFTD and bvFTD may belong to the same disease spectrum. Advanced MRI techniques, objectively identifying brain abnormalities, would therefore be potentially suited to improve the diagnosis of phFTD. (orig.)

  16. Functional connectivity and microstructural white matter changes in phenocopy frontotemporal dementia

    International Nuclear Information System (INIS)

    Meijboom, R.; Steketee, R.M.E.; Lugt, A. van der; Smits, M.; Koning, I. de; Osse, R.J.; Jiskoot, L.C.; Jong, F.J. de; Swieten, J.C. van

    2017-01-01

    Phenocopy frontotemporal dementia (phFTD) is a rare and poorly understood clinical syndrome. PhFTD shows core behavioural variant FTD (bvFTD) symptoms without associated cognitive deficits and brain abnormalities on conventional MRI and without progression. In contrast to phFTD, functional connectivity and white matter (WM) microstructural abnormalities have been observed in bvFTD. We hypothesise that phFTD belongs to the same disease spectrum as bvFTD and investigated whether functional connectivity and microstructural WM changes similar to bvFTD are present in phFTD. Seven phFTD patients without progression or alternative psychiatric diagnosis, 12 bvFTD patients and 17 controls underwent resting state functional MRI (rs-fMRI) and diffusion tensor imaging (DTI). Default mode network (DMN) connectivity and WM measures were compared between groups. PhFTD showed subtly increased DMN connectivity and subtle microstructural changes in frontal WM tracts. BvFTD showed abnormalities in similar regions as phFTD, but had lower increased DMN connectivity and more extensive microstructural WM changes. Our findings can be interpreted as neuropathological changes in phFTD and are in support of the hypothesis that phFTD and bvFTD may belong to the same disease spectrum. Advanced MRI techniques, objectively identifying brain abnormalities, would therefore be potentially suited to improve the diagnosis of phFTD. (orig.)

  17. White matter microstructure in transsexuals and controls investigated by diffusion tensor imaging.

    Science.gov (United States)

    Kranz, Georg S; Hahn, Andreas; Kaufmann, Ulrike; Küblböck, Martin; Hummer, Allan; Ganger, Sebastian; Seiger, Rene; Winkler, Dietmar; Swaab, Dick F; Windischberger, Christian; Kasper, Siegfried; Lanzenberger, Rupert

    2014-11-12

    Biological causes underpinning the well known gender dimorphisms in human behavior, cognition, and emotion have received increased attention in recent years. The advent of diffusion-weighted magnetic resonance imaging has permitted the investigation of the white matter microstructure in unprecedented detail. Here, we aimed to study the potential influences of biological sex, gender identity, sex hormones, and sexual orientation on white matter microstructure by investigating transsexuals and healthy controls using diffusion tensor imaging (DTI). Twenty-three female-to-male (FtM) and 21 male-to-female (MtF) transsexuals, as well as 23 female (FC) and 22 male (MC) controls underwent DTI at 3 tesla. Fractional anisotropy, axial, radial, and mean diffusivity were calculated using tract-based spatial statistics (TBSS) and fiber tractography. Results showed widespread significant differences in mean diffusivity between groups in almost all white matter tracts. FCs had highest mean diffusivities, followed by FtM transsexuals with lower values, MtF transsexuals with further reduced values, and MCs with lowest values. Investigating axial and radial diffusivities showed that a transition in axial diffusivity accounted for mean diffusivity results. No significant differences in fractional anisotropy maps were found between groups. Plasma testosterone levels were strongly correlated with mean, axial, and radial diffusivities. However, controlling for individual estradiol, testosterone, or progesterone plasma levels or for subjects' sexual orientation did not change group differences. Our data harmonize with the hypothesis that fiber tract development is influenced by the hormonal environment during late prenatal and early postnatal brain development. Copyright © 2014 the authors 0270-6474/14/3415466-10$15.00/0.

  18. White Matter Microstructure in Transsexuals and Controls Investigated by Diffusion Tensor Imaging

    Science.gov (United States)

    Kranz, Georg S.; Hahn, Andreas; Kaufmann, Ulrike; Küblböck, Martin; Hummer, Allan; Ganger, Sebastian; Seiger, Rene; Winkler, Dietmar; Swaab, Dick F.; Windischberger, Christian; Kasper, Siegfried; Lanzenberger, Rupert

    2015-01-01

    Biological causes underpinning the well known gender dimorphisms in human behavior, cognition, and emotion have received increased attention in recent years. The advent of diffusion-weighted magnetic resonance imaging has permitted the investigation of the white matter microstructure in unprecedented detail. Here, we aimed to study the potential influences of biological sex, gender identity, sex hormones, and sexual orientation on white matter microstructure by investigating transsexuals and healthy controls using diffusion tensor imaging (DTI). Twenty-three female-to-male (FtM) and 21 male-to-female (MtF) transsexuals, as well as 23 female (FC) and 22 male (MC) controls underwent DTI at 3 tesla. Fractional anisotropy, axial, radial, and mean diffusivity were calculated using tract-based spatial statistics (TBSS) and fiber tractography. Results showed widespread significant differences in mean diffusivity between groups in almost all white matter tracts. FCs had highest mean diffusivities, followed by FtM transsexuals with lower values, MtF transsexuals with further reduced values, and MCs with lowest values. Investigating axial and radial diffusivities showed that a transition in axial diffusivity accounted for mean diffusivity results. No significant differences in fractional anisotropy maps were found between groups. Plasma testosterone levels were strongly correlated with mean, axial, and radial diffusivities. However, controlling for individual estradiol, testosterone, or progesterone plasma levels or for subjects’ sexual orientation did not change group differences. Our data harmonize with the hypothesis that fiber tract development is influenced by the hormonal environment during late prenatal and early postnatal brain development. PMID:25392513

  19. Corpus callosum vasculature predicts white matter microstructure abnormalities following pediatric mild traumatic brain injury.

    Science.gov (United States)

    Wendel, Kara M; Lee, Jeong Bin; Affeldt, Bethann; Hamer, Mary; Harahap-Carrillo, Indira S; Pardo, Andrea C; Obenaus, Andre

    2018-05-09

    Emerging data suggest that pediatric traumatic brain injury (TBI) is associated with impaired developmental plasticity and poorer neuropsychological outcomes than adults with similar head injuries. Unlike adult mild TBI (mTBI), the effects of mTBI on white matter (WM) microstructure and vascular supply are not well-understood in the pediatric population. The cerebral vasculature plays an important role providing necessary nutrients and removing waste. To address this critical element, we examined the microstructure of the corpus callosum (CC) following pediatric mTBI using diffusion tensor imaging (DTI), and investigated myelin, oligodendrocytes, and vasculature of WM with immunohistochemistry. We hypothesized that pediatric mTBI leads to abnormal WM microstructure and impacts the vasculature within the CC, and that these alterations to WM vasculature contribute to the long-term altered microstructure. We induced a closed head injury mTBI at postnatal day 14, then at 4, 14, and 60 days post injury (DPI) mice were sacrificed for analysis. We observed persistent changes in apparent diffusion coefficient (ADC) within the ipsilateral CC following mTBI, indicating microstructural changes, but surprisingly changes in myelin and oligodendrocyte densities were minimal. However, vasculature features of the ipsilateral CC such as vessel density, length, and number of junctions were persistently altered following mTBI. Correlative analysis showed a strong inverse relationship between ADC and vessel density at 60 DPI, suggesting increased vessel density following mTBI may restrict WM diffusion characteristics. Our findings suggest that WM vasculature contributes to the long-term microstructural changes within the ipsilateral CC following mTBI.

  20. Abnormal white matter microstructure among early adulthood smokers: a tract-based spatial statistics study.

    Science.gov (United States)

    Wang, Shuangkun; Zuo, Long; Jiang, Tao; Peng, Peng; Chu, Shuilian; Xiao, Dan

    2017-12-01

    Objectives Cigarette smoking is an important risk factor of central nervous system diseases. However, the white matter (WM) integrity of early adulthood chronic smokers has not been attached enough importance to as it deserves, and the relationship between the chronic smoking effect and the WM is still unclear. The purpose of this study was to investigate whole - brain WM microstructure of early adulthood smokers and explore the structural correlates of behaviorally relevant features of the disorder. Methods We compared multiple DTI-derived indices, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD), between early adulthood smokers (n = 19) and age-, education- and gender-matched controls (n = 23) using a whole-brain tract-based spatial statistics approach. We also explored the correlations of the mean DTI index values with pack-years and Fagerström Test for Nicotine Dependence. Results The smokers showed increased FA in left superior longitudinal fasciculus (SLF), left anterior corona radiate, left superior corona radiate, left posterior corona radiate, left external capsule (EC), left inferior fronto-occipital fasciculus and sagittal stratum (SS), and decreased RD in left SLF. There were significant negative correlations among the average FA in the left external capsule and pack-years in smokers. In addition, significant positive correlation was found between RD values in the left SLF and pack-years. Discussion These findings indicate that smokers show microstructural changes in several white-matter regions. The correlation between the cumulative effect and microstructural WM alternations suggests that WM properties may become the new biomarkers in practice.

  1. White matter microstructure is associated with auditory and tactile processing in children with and without sensory processing disorder

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    Yi Shin Chang

    2016-01-01

    Full Text Available Sensory processing disorders (SPD affect up to 16% of school-aged children, and contribute to cognitive and behavioral deficits impacting affected individuals and their families. While sensory processing differences are now widely recognized in children with autism, children with sensory-based dysfunction who do not meet autism criteria based on social communication deficits remain virtually unstudied. In a previous pilot diffusion tensor imaging (DTI study, we demonstrated that boys with SPD have altered white matter microstructure primarily affecting the posterior cerebral tracts, which subserve sensory processing and integration. This disrupted microstructural integrity, measured as reduced white matter fractional anisotropy (FA, correlated with parent report measures of atypical sensory behavior. In this present study, we investigate white matter microstructure as it relates to tactile and auditory function in depth with a larger, mixed-gender cohort of children 8 to 12 years of age. We continue to find robust alterations of posterior white matter microstructure in children with SPD relative to typically developing children, along with more spatially distributed alterations. We find strong correlations of FA with both parent report and direct measures of tactile and auditory processing across children, with the direct assessment measures of tactile and auditory processing showing a stronger and more continuous mapping to the underlying white matter integrity than the corresponding parent report measures. Based on these findings of microstructure as a neural correlate of sensory processing ability, diffusion MRI merits further investigation as a tool to find biomarkers for diagnosis, prognosis and treatment response in children with SPD. To our knowledge, this work is the first to demonstrate associations of directly measured tactile and non-linguistic auditory function with white matter microstructural integrity -- not just in children with

  2. Reliability of White Matter Microstructural Changes in HIV Infection: Metaanalysis and Confirmation

    Science.gov (United States)

    O’Connor, Erin E.; Jaillard, Assia; Renard, Felix; Zeffiro, Thomas A.

    2017-01-01

    Background Diffusion tensor imaging (DTI) has been widely used to measure HIV effects on white matter (WM) microarchitecture. While many have reported reduced fractional anisotropy (FA) and increased mean diffusivity (MD) in HIV, quantitative inconsistencies across studies are large. Purpose To evaluate the consistency across studies of HIV effects on DTI measures and then examine DTI reliability in a longitudinal seropositive cohort. Study Selection The meta-analysis included 16 cross-sectional studies reporting FA and 12 studies reporting MD in the corpus callosum. Data Analysis Random effects meta-analysis was used to estimate study standardized mean differences (smd) and heterogeneity. DTI longitudinal reliability was estimated in seropositives studied before, and three and six months after, beginning treatment. Data Synthesis Meta-analysis revealed lower FA (smd −0.43; psmd 0.44; p0.96. Limitation Many studies pooled participants with varying treatments, ages and disease durations. Conclusion HIV effects on WM microstructure exhibited substantial variations that could result from acquisition, processing or cohort selection differences. When acquisition parameters and processing were carefully controlled, the resulting DTI measures did not show high temporal variation. HIV effects on WM microstructure may be age dependent. The high longitudinal reliability of DTI WM microstructure measures make them promising disease activity markers. PMID:28596189

  3. Intracranial Fluid Redistribution But No White Matter Microstructural Changes During a Spaceflight Analog.

    Science.gov (United States)

    Koppelmans, Vincent; Pasternak, Ofer; Bloomberg, Jacob J; Dios, Yiri E De; Wood, Scott J; Riascos, Roy; Reuter-Lorenz, Patricia A; Kofman, Igor S; Mulavara, Ajitkumar P; Seidler, Rachael D

    2017-06-09

    The neural correlates of spaceflight-induced sensorimotor impairments are unknown. Head down-tilt bed rest (HDBR) serves as a microgravity analog because it mimics the headward fluid shift and axial body unloading of spaceflight. We investigated focal brain white matter (WM) changes and fluid shifts during 70 days of 6° HDBR in 16 subjects who were assessed pre (2x), during (3x), and post-HDBR (2x). Changes over time were compared to those in control subjects (n = 12) assessed four times over 90 days. Diffusion MRI was used to assess WM microstructure and fluid shifts. Free-Water Imaging was used to quantify distribution of intracranial extracellular free water (FW). Additionally, we tested whether WM and FW changes correlated with changes in functional mobility and balance measures. HDBR resulted in FW increases in fronto-temporal regions and decreases in posterior-parietal regions that largely recovered by two weeks post-HDBR. WM microstructure was unaffected by HDBR. FW decreases in the post-central gyrus and precuneus correlated negatively with balance changes. We previously reported that gray matter increases in these regions were associated with less HDBR-induced balance impairment, suggesting adaptive structural neuroplasticity. Future studies are warranted to determine causality and underlying mechanisms.

  4. Microstructural integrity of white matter tracts amongst older fallers: A DTI study.

    Directory of Open Access Journals (Sweden)

    Yoke Queen Wong

    Full Text Available This study assesses the whole brain microstructural integrity of white matter tracts (WMT among older individuals with a history of falls compared to non-fallers.85 participants (43 fallers, 42 non-fallers were evaluated with conventional MRI and diffusion tensor imaging (DTI sequences of the brain. DTI metrics were obtained from selected WMT using tract-based spatial statistics (TBSS method. This was followed by binary logistic regression to investigate the clinical variables that could act as confounding elements on the outcomes. The TBSS analysis was then repeated, but this time including all significant predictor variables from the regression analysis as TBSS covariates.The mean diffusivity (MD and axial diffusivity (AD and to a lesser extent radial diffusivity (RD values of the projection fibers and commissural bundles were significantly different in fallers (p < 0.05 compared to non-fallers. However, the final logistic regression model obtained showed that only functional reach, white matter lesion volume, hypertension and orthostatic hypotension demonstrated statistical significant differences between fallers and non-fallers. No significant differences were found in the DTI metrics when taking into account age and the four variables as covariates in the repeated analysis.This DTI study of 85 subjects, do not support DTI metrics as a singular factor that contributes independently to the fall outcomes. Other clinical and imaging factors have to be taken into account.

  5. Prenatal and adolescent exposure to tobacco smoke modulates the development of white matter microstructure.

    Science.gov (United States)

    Jacobsen, Leslie K; Picciotto, Marina R; Heath, Christopher J; Frost, Stephen J; Tsou, Kristen A; Dwan, Rita A; Jackowski, Marcel P; Constable, Robert T; Mencl, W Einar

    2007-12-05

    Prenatal exposure to maternal smoking has been linked to cognitive and auditory processing deficits in offspring. Preclinical studies have demonstrated that exposure to nicotine disrupts neurodevelopment during gestation and adolescence, possibly by disrupting the trophic effects of acetylcholine. Given recent clinical and preclinical work suggesting that neurocircuits that support auditory processing may be particularly vulnerable to developmental disruption by nicotine, we examined white matter microstructure in 67 adolescent smokers and nonsmokers with and without prenatal exposure to maternal smoking. The groups did not differ in age, educational attainment, IQ, years of parent education, or symptoms of inattention. Diffusion tensor anisotropy and anatomical magnetic resonance images were acquired, and auditory attention was assessed, in all subjects. Both prenatal exposure and adolescent exposure to tobacco smoke was associated with increased fractional anisotropy (FA) in anterior cortical white matter. Adolescent smoking was also associated with increased FA of regions of the internal capsule that contain auditory thalamocortical and corticofugal fibers. FA of the posterior limb of the left internal capsule was positively correlated with reaction time during performance of an auditory attention task in smokers but not in nonsmokers. Development of anterior cortical and internal capsule fibers may be particularly vulnerable to disruption in cholinergic signaling induced by nicotine in tobacco smoke. Nicotine-induced disruption of the development of auditory corticofugal fibers may interfere with the ability of these fibers to modulate ascending auditory signals, leading to greater noise and reduced efficiency of neurocircuitry that supports auditory processing.

  6. Abnormalities of white matter microstructure in unmedicated obsessive-compulsive disorder and changes after medication.

    Directory of Open Access Journals (Sweden)

    Qing Fan

    Full Text Available BACKGROUND: Abnormalities of myelin integrity have been reported in obsessive-compulsive disorder (OCD using multi-parameter maps of diffusion tensor imaging (DTI. However, it was still unknown to what degree these abnormalities might be affected by pharmacological treatment. OBJECTIVE: To investigate whether the abnormalities of white matter microstructure including myelin integrity exist in OCD and whether they are affected by medication. METHODOLOGY AND PRINCIPAL FINDINGS: Parameter maps of DTI, including fractional anisotropy (FA, axial diffusivity (AD, radial diffusivity (RD and mean diffusivity (MD, were acquired from 27 unmedicated OCD patients (including 13 drug-naïve individuals and 23 healthy controls. Voxel-based analysis was then performed to detect regions with significant group difference. We compared the DTI-derived parameters of 15 patients before and after 12-week Selective Serotonin Reuptake Inhibitor (SSRI therapies. Significant differences of DTI-derived parameters were observed between OCD and healthy groups in multiple structures, mainly within the fronto-striato-thalamo-cortical loop. An increased RD in combination with no change in AD among OCD patients was found in the left medial superior frontal gyrus, temporo-parietal lobe, occipital lobe, striatum, insula and right midbrain. There was no statistical difference in DTI-derived parameters between drug-naive and previously medicated OCD patients. After being medicated, OCD patients showed a reduction in RD of the left striatum and right midbrain, and in MD of the right midbrain. CONCLUSION: Our preliminary findings suggest that abnormalities of white matter microstructure, particularly in terms of myelin integrity, are primarily located within the fronto-striato-thalamo-cortical circuit of individuals with OCD. Some abnormalities may be partly reversed by SSRI treatment.

  7. Atypical functional connectivity in autism spectrum disorder is associated with disrupted white matter microstructural organisation

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    Jane eMcGrath

    2013-09-01

    Full Text Available Disruption of structural and functional neural connectivity has been widely reported in Autism Spectrum Disorder (ASD but there is a striking lack of research attempting to integrate analysis of functional and structural connectivity in the same study population, an approach that may provide key insights into the specific neurobiological underpinnings of altered functional connectivity in autism. The aims of this study were 1. to determine whether functional connectivity abnormalities were associated with structural abnormalities of white matter (WM in ASD and 2. to examine the relationships between aberrant neural connectivity and behaviour in ASD. 22 individuals with ASD and 22 age, IQ-matched controls completed a high-angular-resolution diffusion MRI scan. Structural connectivity was analysed using constrained spherical deconvolution based tractography. Regions for tractography were generated from the results of a previous study, in which 10 pairs of brain regions showed abnormal functional connectivity during visuospatial processing in ASD. WM tracts directly connected 5 of the 10 region pairs that showed abnormal functional connectivity; linking a region in the left occipital lobe (left BA19 and five paired regions: left caudate head, left caudate body, left uncus, left thalamus and left cuneus. Measures of WM microstructural organisation were extracted from these tracts. Fractional anisotropy reductions in the ASD group relative to controls were significant for WM connecting left BA19 to left caudate head and left BA19 to left thalamus. Using a multimodal imaging approach, this study has revealed aberrant white matter microstructure in tracts that directly connect brain regions that are abnormally functionally connected in ASD. These results provide novel evidence to suggest that structural brain pathology may contribute 1. to abnormal functional connectivity and 2. to atypical visuospatial processing in ASD.

  8. White Matter Microstructural Abnormalities in Type 2 Diabetes Mellitus: A Diffusional Kurtosis Imaging Analysis.

    Science.gov (United States)

    Xie, Y; Zhang, Y; Qin, W; Lu, S; Ni, C; Zhang, Q

    2017-03-01

    Increasing DTI studies have demonstrated that white matter microstructural abnormalities play an important role in type 2 diabetes mellitus-related cognitive impairment. In this study, the diffusional kurtosis imaging method was used to investigate WM microstructural alterations in patients with type 2 diabetes mellitus and to detect associations between diffusional kurtosis imaging metrics and clinical/cognitive measurements. Diffusional kurtosis imaging and cognitive assessments were performed on 58 patients with type 2 diabetes mellitus and 58 controls. Voxel-based intergroup comparisons of diffusional kurtosis imaging metrics were conducted, and ROI-based intergroup comparisons were further performed. Correlations between the diffusional kurtosis imaging metrics and cognitive/clinical measurements were assessed after controlling for age, sex, and education in both patients and controls. Altered diffusion metrics were observed in the corpus callosum, the bilateral frontal WM, the right superior temporal WM, the left external capsule, and the pons in patients with type 2 diabetes mellitus compared with controls. The splenium of the corpus callosum and the pons had abnormal kurtosis metrics in patients with type 2 diabetes mellitus. Additionally, altered diffusion metrics in the right prefrontal WM were significantly correlated with disease duration and attention task performance in patients with type 2 diabetes mellitus. With both conventional diffusion and additional kurtosis metrics, diffusional kurtosis imaging can provide additional information on WM microstructural abnormalities in patients with type 2 diabetes mellitus. Our results indicate that WM microstructural abnormalities occur before cognitive decline and may be used as neuroimaging markers for predicting the early cognitive impairment in patients with type 2 diabetes mellitus. © 2017 by American Journal of Neuroradiology.

  9. Microstructural white matter alterations and hippocampal volumes are associated with cognitive deficits in craniopharyngioma.

    Science.gov (United States)

    Fjalldal, S; Follin, C; Svärd, D; Rylander, L; Gabery, S; Petersén, Å; van Westen, D; Sundgren, P C; Björkman-Burtscher, I M; Lätt, J; Ekman, B; Johanson, A; Erfurth, E M

    2018-06-01

    Patients with craniopharyngioma (CP) and hypothalamic lesions (HL) have cognitive deficits. Which neural pathways are affected is unknown. To determine whether there is a relationship between microstructural white matter (WM) alterations detected with diffusion tensor imaging (DTI) and cognition in adults with childhood-onset CP. A cross-sectional study with a median follow-up time of 22 (6-49) years after operation. The South Medical Region of Sweden (2.5 million inhabitants). Included were 41 patients (24 women, ≥17 years) surgically treated for childhood-onset CP between 1958-2010 and 32 controls with similar age and gender distributions. HL was found in 23 patients. Subjects performed cognitive tests and magnetic resonance imaging, and images were analyzed using DTI of uncinate fasciculus, fornix, cingulum, hippocampus and hypothalamus as well as hippocampal volumetry. Right uncinate fasciculus was significantly altered ( P  ≤ 0.01). Microstructural WM alterations in left ventral cingulum were significantly associated with worse performance in visual episodic memory, explaining approximately 50% of the variation. Alterations in dorsal cingulum were associated with worse performance in immediate, delayed recall and recognition, explaining 26-38% of the variation, and with visuospatial ability and executive function, explaining 19-29%. Patients who had smaller hippocampal volume had worse general knowledge ( P  = 0.028), and microstructural WM alterations in hippocampus were associated with a decline in general knowledge and episodic visual memory. A structure to function relationship is suggested between microstructural WM alterations in cingulum and in hippocampus with cognitive deficits in CP. © 2018 The authors.

  10. The influence of comorbid oppositional defiant disorder on white matter microstructure in attention-deficit/hyperactivity disorder

    NARCIS (Netherlands)

    van Ewijk, Hanneke; Noordermeer, Siri D. S.; Heslenfeld, Dirk J.; Luman, Marjolein; Hartman, Catharina A.; Hoekstra, Pieter J.; Faraone, Stephen V.; Franke, Barbara; Buitelaar, Jan K.; Oosterlaan, J.

    Attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) are highly comorbid disorders. ADHD has been associated with altered white matter (WM) microstructure, though the literature is inconsistent, which may be due to differences in the in- or exclusion of

  11. White Matter Microstructure of the Human Mirror Neuron System Is Related to Symptom Severity in Adults with Autism

    Science.gov (United States)

    Fründt, Odette; Schulz, Robert; Schöttle, Daniel; Cheng, Bastian; Thomalla, Götz; Braaß, Hanna; Ganos, Christos; David, Nicole; Peiker, Ina; Engel, Andreas K.; Bäumer, Tobias; Münchau, Alexander

    2018-01-01

    Mirror neuron system (MNS) dysfunctions might underlie deficits in autism spectrum disorders (ASD). Diffusion tensor imaging based probabilistic tractography was conducted in 15 adult ASD patients and 13 matched, healthy controls. Fractional anisotropy (FA) was quantified to assess group differences in tract-related white matter microstructure of…

  12. White matter microstructure and developmental improvement of hyperactive/impulsive symptoms in Attention-Deficit/Hyperactivity Disorder

    NARCIS (Netherlands)

    Francx, W.C.L.; Zwiers, M.P.; Mennes, M.J.J.; Oosterlaan, J.; Heslenfeld, D.J.; Hoekstra, P.J.; Hartman, C.A.; Franke, B.; Faraone, S.V; O'Dwyer, L.G.; Buitelaar, J.K.

    2015-01-01

    Background A developmental improvement of symptoms in Attention-Deficit/Hyperactivity Disorder (ADHD) is frequently reported, but the underlying neurobiological substrate has not been identified. The aim of this study was to determine whether white matter microstructure is related to developmental

  13. White matter microstructure and developmental improvement of hyperactive/impulsive symptoms in attention-deficit/hyperactivity disorder

    NARCIS (Netherlands)

    Francx, Winke; Zwiers, Marcel P.; Mennes, Maarten; Oosterlaan, Jaap; Heslenfeld, Dirk; Hoekstra, Pieter J.; Hartman, Catharina A.; Franke, Barbara; Faraone, Stephen V.; O'Dwyer, Laurence; Buitelaar, Jan K.

    2015-01-01

    Background: A developmental improvement of symptoms in attention-deficit/hyperactivity disorder (ADHD) is frequently reported, but the underlying neurobiological substrate has not been identified. The aim of this study was to determine whether white matter microstructure is related to developmental

  14. Executive Functions in Healthy Older Adults Are Differentially Related to Macro- and Microstructural White Matter Characteristics of the Cerebral Lobes

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    Sarah Hirsiger

    2017-11-01

    Full Text Available Aging is associated with microstructural white matter (WM changes. WM microstructural characteristics, measured with diffusion tensor imaging (DTI, are different in normal appearing white matter (NAWM and WM hyperintensities (WMH. It is largely unknown how the microstructural properties of WMH are associated with cognition and if there are regional effects for specific cognitive domains. We therefore examined within 200 healthy older participants (a differences in microstructural characteristics of NAWM and WMH per cerebral lobe; and (b the association of macrostructural (WMH volume and microstructural characteristics (within NAWM and WMH separately of each lobe with measures of executive function and processing speed. Multi-modal imaging (i.e., T1, DTI, and FLAIR was used to assess WM properties. The Stroop and the Trail Making Test were used to measure inhibition, task-switching (both components of executive function, and processing speed. We observed that age was associated with deterioration of white matter microstructure of the NAWM, most notably in the frontal lobe. Older participants had larger WMH volumes and lowest fractional anisotropy values within WMH were found in the frontal lobe. Task-switching was associated with cerebral NAWM volume and NAWM volume of all lobes. Processing speed was associated with total NAWM volume, and microstructural properties of parietal NAWM, the parietal WMH, and the temporal NAWM. Task-switching was related to microstructural properties of WMH of the frontal lobe and WMH volume of the parietal lobe. Our results confirm that executive functioning and processing speed are uniquely associated with macro- and microstructural properties of NAWM and WMH. We further demonstrate for the first time that these relationships differ by lobar region. This warrants the consideration of these distinct WM indices when investigating cognitive function.

  15. A Whole-Brain Investigation of White Matter Microstructure in Adolescents with Conduct Disorder.

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    Sagari Sarkar

    Full Text Available The biological basis of severe antisocial behaviour in adolescents is poorly understood. We recently reported that adolescents with conduct disorder (CD have significantly increased fractional anisotropy (FA of the uncinate fasciculus (a white matter (WM tract that connects the amygdala to the frontal lobe compared to their non-CD peers. However, the extent of WM abnormality in other brain regions is currently unclear.We used tract-based spatial statistics to investigate whole brain WM microstructural organisation in 27 adolescent males with CD, and 21 non-CD controls. We also examined relationships between FA and behavioural measures. Groups did not differ significantly in age, ethnicity, or substance use history.The CD group, compared to controls, had clusters of significantly greater FA in 7 brain regions corresponding to: 1 the bilateral inferior and superior cerebellar peduncles, corticopontocerebellar tract, posterior limb of internal capsule, and corticospinal tract; 2 right superior longitudinal fasciculus; and 3 left cerebellar WM. Severity of antisocial behavior and callous-unemotional symptoms were significantly correlated with FA in several of these regions across the total sample, but not in the CD or control groups alone.Adolescents with CD have significantly greater FA than controls in WM regions corresponding predominantly to the fronto-cerebellar circuit. There is preliminary evidence that variation in WM microstructure may be dimensionally related to behaviour problems in youngsters. These findings are consistent with the hypothesis that antisocial behaviour in some young people is associated with abnormalities in WM 'connectivity'.

  16. A Whole-Brain Investigation of White Matter Microstructure in Adolescents with Conduct Disorder.

    Science.gov (United States)

    Sarkar, Sagari; Dell'Acqua, Flavio; Froudist Walsh, Seán; Blackwood, Nigel; Scott, Stephen; Craig, Michael C; Deeley, Quinton; Murphy, Declan G M

    2016-01-01

    The biological basis of severe antisocial behaviour in adolescents is poorly understood. We recently reported that adolescents with conduct disorder (CD) have significantly increased fractional anisotropy (FA) of the uncinate fasciculus (a white matter (WM) tract that connects the amygdala to the frontal lobe) compared to their non-CD peers. However, the extent of WM abnormality in other brain regions is currently unclear. We used tract-based spatial statistics to investigate whole brain WM microstructural organisation in 27 adolescent males with CD, and 21 non-CD controls. We also examined relationships between FA and behavioural measures. Groups did not differ significantly in age, ethnicity, or substance use history. The CD group, compared to controls, had clusters of significantly greater FA in 7 brain regions corresponding to: 1) the bilateral inferior and superior cerebellar peduncles, corticopontocerebellar tract, posterior limb of internal capsule, and corticospinal tract; 2) right superior longitudinal fasciculus; and 3) left cerebellar WM. Severity of antisocial behavior and callous-unemotional symptoms were significantly correlated with FA in several of these regions across the total sample, but not in the CD or control groups alone. Adolescents with CD have significantly greater FA than controls in WM regions corresponding predominantly to the fronto-cerebellar circuit. There is preliminary evidence that variation in WM microstructure may be dimensionally related to behaviour problems in youngsters. These findings are consistent with the hypothesis that antisocial behaviour in some young people is associated with abnormalities in WM 'connectivity'.

  17. Effects of insulin resistance on white matter microstructure in middle-aged and older adults

    Science.gov (United States)

    Coutu, Jean-Philippe; Rosas, H. Diana; Salat, David H.

    2014-01-01

    Objective: To investigate the potential relationship between insulin resistance (IR) and white matter (WM) microstructure using diffusion tensor imaging in cognitively healthy middle-aged and older adults. Methods: Diffusion tensor imaging was acquired from 127 individuals (age range 41–86 years). IR was evaluated by the homeostasis model assessment of IR (HOMA-IR). Participants were divided into 2 groups based on HOMA-IR values: “high HOMA-IR” (≥2.5, n = 27) and “low HOMA-IR” (HOMA-IR group demonstrated decreased axial diffusivity broadly throughout the cerebral WM in areas such as the corpus callosum, corona radiata, cerebral peduncle, posterior thalamic radiation, and right superior longitudinal fasciculus, and WM underlying the frontal, parietal, and temporal lobes, as well as decreased fractional anisotropy in the body and genu of corpus callosum and parts of the superior and anterior corona radiata, compared with the low HOMA-IR group, independent of age, WM signal abnormality volume, and antihypertensive medication status. These regions additionally demonstrated linear associations between diffusion measures and HOMA-IR across all subjects, with higher HOMA-IR values being correlated with lower axial diffusivity. Conclusions: In generally healthy adults, greater IR is associated with alterations in WM tissue integrity. These cross-sectional findings suggest that IR contributes to WM microstructural alterations in middle-aged and older adults. PMID:24771537

  18. Effects of long-term mindfulness meditation on brain's white matter microstructure and its aging.

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    Davide eLaneri

    2016-01-01

    Full Text Available Although research on the effects of mindfulness meditation (MM is increasing, still very little has been done to address its influence on the white matter (WM of the brain. We hypothesized that the practice of MM might affect the WM microstructure adjacent to five brain regions of interest associated with mindfulness. Diffusion tensor imaging was employed on samples of meditators and non-meditators (n=64 in order to investigate the effects of MM on group difference and aging. Tract-Based Spatial Statistics was used to estimate the fractional anisotrophy of the WM connected to the thalamus, insula, amygdala, hippocampus and anterior cingulate cortex. The subsequent generalized linear model analysis revealed group differences and a group-by-age interaction in all five selected regions. These data provide preliminary indications that the practice of MM might result in WM matter connectivity change and might provide evidence on its ability to help diminish age-related WM degeneration in key regions which participate in processes of mindfulness.

  19. Microstructural Abnormalities of Short-Distance White Matter Tracts in Autism Spectrum Disorder

    Science.gov (United States)

    Shukla, Dinesh K.; Keehn, Brandon; Smylie, Daren M.; Muller, Ralph-Axel

    2011-01-01

    Recent functional connectivity magnetic resonance imaging and diffusion tensor imaging (DTI) studies have suggested atypical functional connectivity and reduced integrity of long-distance white matter fibers in autism spectrum disorder (ASD). However, evidence for short-distance white matter fibers is still limited, despite some speculation of…

  20. Normal white matter microstructure in women long-term recovered from anorexia nervosa: A diffusion tensor imaging study.

    Science.gov (United States)

    Bang, Lasse; Rø, Øyvind; Endestad, Tor

    2018-01-01

    Studies point to white matter (WM) microstructure alterations in both adolescent and adult patients with anorexia nervosa (AN). These include reduced fractional anisotropy in several WM fiber tracts, suggesting reduced WM integrity. The extent to which these alterations are reversible with recovery from AN is unclear. There is a paucity of research investigating the presence of WM microstructure alterations in recovered AN patients, and results are inconsistent. This study aimed to investigate the presence of WM microstructure alterations in women long-term recovered from AN. Twenty-one adult women who were recovered from AN for at least 1 year were compared to 21 adult comparison women. Participants were recruited via user-organizations for eating disorders, local advertisements, and online forums. Diffusion tensor imaging was used to compare WM microstructure between groups. Correlations between WM microstructure and clinical characteristics were also explored. There were no statistically significant between-group differences in WM microstructure. These null findings remained when employing liberal alpha level thresholds. Furthermore, there were no statistically significant correlations between WM microstructure and clinical characteristics. Our findings showed normal WM microstructure in long-term recovered patients, indicating the alterations observed during the acute phase are reversible. Given the paucity of research and inconsistent findings, future studies are warranted to determine the presence of WM microstructure alterations following recovery from AN. © 2017 Wiley Periodicals, Inc.

  1. White matter microstructural changes in adolescent anorexia nervosa including an exploratory longitudinal study

    Science.gov (United States)

    Vogel, Katja; Timmers, Inge; Kumar, Vinod; Nickl-Jockschat, Thomas; Bastiani, Matteo; Roebroek, Alard; Herpertz-Dahlmann, Beate; Konrad, Kerstin; Goebel, Rainer; Seitz, Jochen

    2016-01-01

    Background Anorexia nervosa (AN) often begins in adolescence, however, the understanding of the underlying pathophysiology at this developmentally important age is scarce, impeding early interventions. We used diffusion tensor imaging (DTI) to investigate microstructural white matter (WM) brain changes including an experimental longitudinal follow-up. Methods We acquired whole brain diffusion-weighted brain scans of 22 adolescent female hospitalized patients with AN at admission and nine patients longitudinally at discharge after weight rehabilitation. Patients (10–18 years) were compared to 21 typically developing controls (TD). Tract-based spatial statistics (TBSS) were applied to compare fractional anisotropy (FA) across groups and time points. Associations between average FA values of the global WM skeleton and weight as well as illness duration parameters were analyzed by multiple linear regression. Results We observed increased FA in bilateral frontal, parietal and temporal areas in AN patients at admission compared to TD. Higher FA of the global WM skeleton at admission was associated with faster weight loss prior to admission. Exploratory longitudinal analysis showed this FA increase to be partially normalized after weight rehabilitation. Conclusions Our findings reveal a markedly different pattern of WM microstructural changes in adolescent AN compared to most previous results in adult AN. This could signify a different susceptibility and reaction to semi-starvation in the still developing brain of adolescents or a time-dependent pathomechanism differing with extend of chronicity. Higher FA at admission in adolescents with AN could point to WM fibers being packed together more closely. PMID:27182488

  2. White matter microstructural abnormalities in the frontal lobe of adults with antisocial personality disorder.

    Science.gov (United States)

    Sundram, Frederick; Deeley, Quinton; Sarkar, Sagari; Daly, Eileen; Latham, Richard; Craig, Michael; Raczek, Malgorzata; Fahy, Tom; Picchioni, Marco; Barker, Gareth J; Murphy, Declan G M

    2012-02-01

    Antisocial personality disorder (ASPD) and psychopathy involve significant interpersonal and behavioural impairments. However, little is known about their underlying neurobiology and in particular, abnormalities in white matter (WM) microstructure. A preliminary diffusion tensor magnetic resonance imaging (DT-MRI) study of adult psychopaths employing tractography revealed abnormalities in the right uncinate fasciculus (UF) (Craig et al., 2009), indicating fronto-limbic disconnectivity. However, it is not clear whether WM abnormalities are restricted to this tract or are or more widespread, including other tracts which are involved in connectivity with the frontal lobe. We performed whole brain voxel-based analyses on WM fractional anisotropy (FA) and mean diffusivity (MD) maps acquired with DT-MRI to compare 15 adults with ASPD and healthy age, handedness and IQ-matched controls. Also, within ASPD subjects we related differences in FA and MD to measures of psychopathy. Significant WM FA reduction and MD increases were found respectively in ASPD subjects relative to controls. FA was bilaterally reduced in the genu of corpus callosum while in the right frontal lobe FA reduction was found in the UF, inferior fronto-occipital fasciculus (IFOF), anterior corona radiata and anterior limb and genu of the internal capsule. These differences negatively correlated with measures of psychopathy. Also in the right frontal lobe, increased MD was found in the IFOF and UF, and the corpus callosum and anterior corona radiata. There was a significant positive correlation between MD and psychopathy scores. The present study confirms a previous report of reduced FA in the UF. Additionally, we report for the first time, FA deficits in tracts involved in interhemispheric as well as frontal lobe connectivity in conjunction with MD increases in the frontal lobe. Hence, we provide evidence of significant WM microstructural abnormalities in frontal brain regions in ASPD and psychopathy

  3. White Matter Microstructural Changes Following Quadrato Motor Training: A Longitudinal Study

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    Claudia Piervincenzi

    2017-12-01

    Full Text Available Diffusion tensor imaging (DTI is an important way to characterize white matter (WM microstructural changes. While several cross-sectional DTI studies investigated possible links between mindfulness practices and WM, only few longitudinal investigations focused on the effects of these practices on WM architecture, behavioral change, and the relationship between them. To this aim, in the current study, we chose to conduct an unbiased tract-based spatial statistics (TBSS analysis (n = 35 healthy participants to identify longitudinal changes in WM diffusion parameters following 6 and 12 weeks of daily Quadrato Motor Training (QMT, a whole-body mindful movement practice aimed at improving well-being by enhancing attention, coordination, and creativity. We also investigated the possible relationship between training-induced WM changes and concomitant changes in creativity, self-efficacy, and motivation. Our results indicate that following 6 weeks of daily QMT, there was a bilateral increase of fractional anisotropy (FA in tracts related to sensorimotor and cognitive functions, including the corticospinal tracts, anterior thalamic radiations, and uncinate fasciculi, as well as in the left inferior fronto-occipital, superior and inferior longitudinal fasciculi. Interestingly, significant FA increments were still present after 12 weeks of QMT in most of the above WM tracts, but only in the left hemisphere. FA increase was accompanied by a significant decrease of radial diffusivity (RD, supporting the leading role of myelination processes in training-related FA changes. Finally, significant correlations were found between training-induced diffusion changes and increased self-efficacy as well as creativity. Together, these findings suggest that QMT can improve WM integrity and support the existence of possible relationships between training-related WM microstructural changes and behavioral change.

  4. Endothelial Function Is Associated with White Matter Microstructure and Executive Function in Older Adults

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    Nathan F. Johnson

    2017-08-01

    Full Text Available Age-related declines in endothelial function can lead to cognitive decline. However, little is known about the relationships between endothelial function and specific neurocognitive functions. This study explored the relationship between measures of endothelial function (reactive hyperemia index; RHI, white matter (WM health (fractional anisotropy, FA, and WM hyperintensity volume, WMH, and executive function (Trail Making Test (TMT; Trail B − Trail A. Participants were 36 older adults between the ages of 59 and 69 (mean age = 63.89 years, SD = 2.94. WMH volume showed no relationship with RHI or executive function. However, there was a positive relationship between RHI and FA in the genu and body of the corpus callosum. In addition, higher RHI and FA were each associated with better executive task performance. Tractography was used to localize the WM tracts associated with RHI to specific portions of cortex. Results indicated that the RHI-FA relationship observed in the corpus callosum primarily involved tracts interconnecting frontal regions, including the superior frontal gyrus (SFG and frontopolar cortex, linked with executive function. These findings suggest that superior endothelial function may help to attenuate age-related declines in WM microstructure in portions of the corpus callosum that interconnect prefrontal brain regions involved in executive function.

  5. The Eye as a Window to the Brain: Neuroretinal Thickness Is Associated With Microstructural White Matter Injury in HIV-Infected Children

    NARCIS (Netherlands)

    Blokhuis, Charlotte; Demirkaya, Nazli; Cohen, Sophie; Wit, Ferdinand W. N. M.; Scherpbier, Henriëtte J.; Reiss, Peter; Abramoff, Michael D.; Caan, Matthan W. A.; Majoie, Charles B. L. M.; Verbraak, Frank D.; Pajkrt, Dasja

    2016-01-01

    Despite combination antiretroviral therapy (cART), perinatal HIV-infection can cause decreased gray and white matter volume, microstructural white matter injury, and retinal structural abnormalities. As neuroretinal tissue is directly connected to the brain, these deficits may have a shared

  6. Deep white matter hyperintensities, microstructural integrity and dual task walking in older people.

    Science.gov (United States)

    Ghanavati, Tabassom; Smitt, Myriam Sillevis; Lord, Stephen R; Sachdev, Perminder; Wen, Wei; Kochan, Nicole A; Brodaty, Henry; Delbaere, Kim

    2018-01-03

    To examine neural, physiological and cognitive influences on gait speed under single and dual-task conditions. Sixty-two community-dwelling older people (aged 80.0 ± 4.2 years) participated in our study. Gait speed was assessed with a timed 20-meter walk under single and dual-task (reciting alternate letters of the alphabet) conditions. Participants also underwent tests to estimate physiological fall risk based on five measures of sensorimotor function, cognitive function across five domains, brain white matter (WM) hyperintensities and WM microstructural integrity by measuring fractional anisotropy (FA). Univariate linear regression analyses showed that global physiological and cognitive measures were associated with single (β = 0.594 and β=-0.297, respectively) and dual-task gait speed (β = 0.306 and β=-0.362, respectively). Deep WMHs were associated with dual-task gait speed only (β = 0.257). Multivariate mediational analyses showed that global and executive cognition reduced the strength of the association between deep WMHs and dual-task gait speed by 27% (β = 0.188) and 44% (β = 0.145) respectively. There was a significant linear association between single-task gait speed and mean FA values of the genu (β=-0.295) and splenium (β=-0.326) of the corpus callosum, and between dual-task gait speed and mean FA values of Superior Cerebellar Peduncle (β=-0.284), splenium of the Corpus Callosum (β=-0.286) and Cingulum (β=-0.351). Greater deep WMH volumes are associated with slower walking speed under dual-task conditions, and this relationship is mediated in part by global cognition and executive abilities specifically. Furthermore, both cerebellum and cingulum are related to dual-task walking due to their role in motor skill performance and attention, respectively.

  7. Development of white matter microstructure in relation to verbal and visuospatial working memory-A longitudinal study.

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    Krogsrud, Stine K; Fjell, Anders M; Tamnes, Christian K; Grydeland, Håkon; Due-Tønnessen, Paulina; Bjørnerud, Atle; Sampaio-Baptista, Cassandra; Andersson, Jesper; Johansen-Berg, Heidi; Walhovd, Kristine B

    2018-01-01

    Working memory capacity is pivotal for a broad specter of cognitive tasks and develops throughout childhood. This must in part rely on development of neural connections and white matter microstructure maturation, but there is scarce knowledge of specific relations between this and different aspects of working memory. Diffusion tensor imaging (DTI) enables us to study development of brain white matter microstructure. In a longitudinal DTI study of 148 healthy children between 4 and 11 years scanned twice with an on average 1.6 years interval, we characterized change in fractional anisotropy (FA), mean (MD), radial (RD) and axial diffusivity (AD) in 10 major white matter tracts hypothesized to be of importance for working memory. The results showed relationships between change in several tracts and change in visuospatial working memory. Specifically, improvement in visuospatial working memory capacity was significantly associated with decreased MD, RD and AD in inferior longitudinal fasciculus (ILF), inferior fronto-occipital fasciculus (IFOF) and uncinate fasciculus (UF) in the right hemisphere, as well as forceps major (FMaj). No significant relationships were found between change in DTI metrics and change in verbal working memory capacity. These findings yield new knowledge about brain development and corresponding working memory improvements in childhood.

  8. Development of white matter microstructure in relation to verbal and visuospatial working memory—A longitudinal study

    Science.gov (United States)

    Fjell, Anders M.; Tamnes, Christian K.; Grydeland, Håkon; Due-Tønnessen, Paulina; Bjørnerud, Atle; Sampaio-Baptista, Cassandra; Andersson, Jesper; Johansen-Berg, Heidi; Walhovd, Kristine B.

    2018-01-01

    Working memory capacity is pivotal for a broad specter of cognitive tasks and develops throughout childhood. This must in part rely on development of neural connections and white matter microstructure maturation, but there is scarce knowledge of specific relations between this and different aspects of working memory. Diffusion tensor imaging (DTI) enables us to study development of brain white matter microstructure. In a longitudinal DTI study of 148 healthy children between 4 and 11 years scanned twice with an on average 1.6 years interval, we characterized change in fractional anisotropy (FA), mean (MD), radial (RD) and axial diffusivity (AD) in 10 major white matter tracts hypothesized to be of importance for working memory. The results showed relationships between change in several tracts and change in visuospatial working memory. Specifically, improvement in visuospatial working memory capacity was significantly associated with decreased MD, RD and AD in inferior longitudinal fasciculus (ILF), inferior fronto-occipital fasciculus (IFOF) and uncinate fasciculus (UF) in the right hemisphere, as well as forceps major (FMaj). No significant relationships were found between change in DTI metrics and change in verbal working memory capacity. These findings yield new knowledge about brain development and corresponding working memory improvements in childhood. PMID:29689058

  9. White Matter Microstructure in Superior Longitudinal Fasciculus Associated with Spatial Working Memory Performance in Children

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    Vestergaard, Martin; Madsen, Kathrine Skak; Baare, William F. C.; Skimminge, Arnold; Ejersbo, Lisser Rye; Ramsoy, Thomas Z.; Gerlach, Christian; Akeson, Per; Paulson, Olaf B.; Jernigan, Terry L.

    2011-01-01

    During childhood and adolescence, ongoing white matter maturation in the fronto-parietal cortices and connecting fiber tracts is measurable with diffusion-weighted imaging. Important questions remain, however, about the links between these changes and developing cognitive functions. Spatial working memory (SWM) performance improves significantly…

  10. Cortical grey matter and subcortical white matter brain microstructural changes in schizophrenia are localised and age independent: a case-control diffusion tensor imaging study.

    Science.gov (United States)

    Chiapponi, Chiara; Piras, Fabrizio; Piras, Federica; Fagioli, Sabrina; Caltagirone, Carlo; Spalletta, Gianfranco

    2013-01-01

    It is still unknown whether the structural brain impairments that characterize schizophrenia (SZ) worsen during the lifetime. Here, we aimed to describe age-related microstructural brain changes in cortical grey matter and subcortical white matter of patients affected by SZ. In this diffusion tensor imaging study, we included 69 patients diagnosed with SZ and 69 healthy control (HC) subjects, age and gender matched. We carried out analyses of covariance, with diagnosis as fixed factor and brain diffusion-related parameters as dependent variables, and controlled for the effect of education. White matter fractional anisotropy decreased in the entire age range spanned (18-65 years) in both SZ and HC and was significantly lower in younger patients with SZ, with no interaction (age by diagnosis) effect in fiber tracts including corpus callosum, corona radiata, thalamic radiations and external capsule. Also, grey matter mean diffusivity increased in the entire age range in both SZ and HC and was significantly higher in younger patients, with no age by diagnosis interaction in the left frontal operculum cortex, left insula and left planum polare and in the right temporal pole and right intracalcarine cortex. In individuals with SZ we found that localized brain cortical and white matter subcortical microstructural impairments appear early in life but do not worsen in the 18-65 year age range.

  11. Cortical grey matter and subcortical white matter brain microstructural changes in schizophrenia are localised and age independent: a case-control diffusion tensor imaging study.

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    Chiara Chiapponi

    Full Text Available It is still unknown whether the structural brain impairments that characterize schizophrenia (SZ worsen during the lifetime. Here, we aimed to describe age-related microstructural brain changes in cortical grey matter and subcortical white matter of patients affected by SZ. In this diffusion tensor imaging study, we included 69 patients diagnosed with SZ and 69 healthy control (HC subjects, age and gender matched. We carried out analyses of covariance, with diagnosis as fixed factor and brain diffusion-related parameters as dependent variables, and controlled for the effect of education. White matter fractional anisotropy decreased in the entire age range spanned (18-65 years in both SZ and HC and was significantly lower in younger patients with SZ, with no interaction (age by diagnosis effect in fiber tracts including corpus callosum, corona radiata, thalamic radiations and external capsule. Also, grey matter mean diffusivity increased in the entire age range in both SZ and HC and was significantly higher in younger patients, with no age by diagnosis interaction in the left frontal operculum cortex, left insula and left planum polare and in the right temporal pole and right intracalcarine cortex. In individuals with SZ we found that localized brain cortical and white matter subcortical microstructural impairments appear early in life but do not worsen in the 18-65 year age range.

  12. White matter microstructure and developmental improvement of hyperactive/impulsive symptoms in attention-deficit/hyperactivity disorder.

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    Francx, Winke; Zwiers, Marcel P; Mennes, Maarten; Oosterlaan, Jaap; Heslenfeld, Dirk; Hoekstra, Pieter J; Hartman, Catharina A; Franke, Barbara; Faraone, Stephen V; O'Dwyer, Laurence; Buitelaar, Jan K

    2015-12-01

    A developmental improvement of symptoms in attention-deficit/hyperactivity disorder (ADHD) is frequently reported, but the underlying neurobiological substrate has not been identified. The aim of this study was to determine whether white matter microstructure is related to developmental improvement of ADHD symptoms. A cross-sectional magnetic resonance imaging (MRI) analysis was embedded in a prospective follow-up of an adolescent cohort of ADHD and control subjects (NeuroIMAGE). Mean age at baseline was 11.9 years, mean interval of follow-up was 5.9 years. About 75.3% of the original cohort was retained successfully. Data of 101 participants with ADHD combined type at baseline and 40 healthy controls were analysed. ADHD symptoms were measured with semistructured, investigator-based interviews and Conners' questionnaires, on the basis of DSM-IV criteria. Fractional anisotropy (FA) and mean diffusivity (MD) indices of white matter microstructure were measured using whole brain diffusion tensor imaging at follow-up only. In a dimensional analysis FA and MD were related to change in ADHD symptoms. To link this analysis to DSM-IV diagnoses, a post hoc categorical group analysis was conducted comparing participants with persistent (n = 59) versus remittent (n = 42) ADHD and controls. Over time, participants with ADHD showed improvement mainly in hyperactive/impulsive symptoms. This improvement was associated with lower FA and higher MD values in the left corticospinal tract at follow-up. Findings of the dimensional and the categorical analysis strongly converged. Changes in inattentive symptoms over time were minimal and not related to white matter microstructure. The corticospinal tract is important in the control of voluntary movements, suggesting the importance of the motor system in the persistence of hyperactive/impulsive symptoms. © 2015 Association for Child and Adolescent Mental Health.

  13. White Matter Microstructure in Superior Longitudinal Fasciculus Associated with Spatial Working Memory Performance in Children

    DEFF Research Database (Denmark)

    Vestergaard, Martin; Madsen, Kathrine Skak; Baaré, William F C

    2011-01-01

    During childhood and adolescence, ongoing white matter maturation in the fronto-parietal cortices and connecting fiber tracts is measurable with diffusion-weighted imaging. Important questions remain, however, about the links between these changes and developing cognitive functions. Spatial working...... memory (SWM) performance improves significantly throughout the childhood years, and several lines of evidence implicate the left fronto-parietal cortices and connecting fiber tracts in SWM processing. Here we report results from a study of 76 typically developing children, 7 to 13 years of age. We...... hypothesized that better SWM performance would be associated with increased fractional anisotropy (FA) in a left fronto-parietal network composed of the superior longitudinal fasciculus (SLF), the regional white matter underlying the dorsolateral pFC, and the posterior parietal cortex. As hypothesized, we...

  14. Patterns of white matter microstructure in individuals at ultra-high-risk for psychosis

    DEFF Research Database (Denmark)

    Krakauer, K; Ebdrup, B H; Glenthøj, B Y

    2017-01-01

    BACKGROUND: Individuals at ultra-high-risk (UHR) for psychosis present with emerging symptoms and decline in functioning. Previous univariate analyses have indicated widespread white matter (WM) aberrations in multiple brain regions in UHR individuals and patients with schizophrenia. Using multiv......, MO, and higher RD. CONCLUSIONS: UHR individuals demonstrate complex brain patterns of WM abnormalities. Despite the subtle psychopathology of UHR individuals, aberrations in WM appear associated with positive and negative symptoms as well as level of functioning....

  15. Age and Alzheimer's pathology disrupt default mode network functioning via alterations in white matter microstructure but not hyperintensities.

    Science.gov (United States)

    Brown, Christopher A; Jiang, Yang; Smith, Charles D; Gold, Brian T

    2018-04-19

    The default mode network (DMN) comprises defined brain regions contributing to internally-directed thought processes. Reductions in task-induced deactivation in the DMN have been associated with increasing age and poorer executive task performance, but factors underlying these functional changes remain unclear. We investigated contributions of white matter (WM) microstructure, WM hyperintensities (WMH) and Alzheimer's pathology to age-related alterations in DMN function. Thirty-five cognitively normal older adults and 29 younger adults underwent working memory task fMRI and diffusion tensor imaging. In the older adults, we measured cerebrospinal fluid tau and Aβ 42 (markers of AD pathology), and WMH on FLAIR imaging (marker of cerebrovascular disease). We identified a set of regions showing DMN deactivation and a set of inter-connecting WM tracts (DMN-WM) common to both age groups. There were negative associations between DMN deactivation and task performance in older adults, consistent with previous studies. Decreased DMN deactivation was associated with AD pathology and WM microstructure but not with WMH volume. Mediation analyses showed that WM microstructure mediated declines in DMN deactivation associated with both aging and AD pathology. Together these results suggest that AD pathology may exert a "second-hit" on WM microstructure, over-and-above the effects of age, both contributing to diminished DMN deactivation in older adults. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. White-matter microstructure and language lateralization in left-handers: a whole-brain MRI analysis.

    Science.gov (United States)

    Perlaki, Gabor; Horvath, Reka; Orsi, Gergely; Aradi, Mihaly; Auer, Tibor; Varga, Eszter; Kantor, Gyongyi; Altbäcker, Anna; John, Flora; Doczi, Tamas; Komoly, Samuel; Kovacs, Norbert; Schwarcz, Attila; Janszky, Jozsef

    2013-08-01

    Most people are left-hemisphere dominant for language. However the neuroanatomy of language lateralization is not fully understood. By combining functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI), we studied whether language lateralization is associated with cerebral white-matter (WM) microstructure. Sixteen healthy, left-handed women aged 20-25 were included in the study. Left-handers were targeted in order to increase the chances of involving subjects with atypical language lateralization. Language lateralization was determined by fMRI using a verbal fluency paradigm. Tract-based spatial statistics analysis of DTI data was applied to test for WM microstructural correlates of language lateralization across the whole brain. Fractional anisotropy and mean diffusivity were used as indicators of WM microstructural organization. Right-hemispheric language dominance was associated with reduced microstructural integrity of the left superior longitudinal fasciculus and left-sided parietal lobe WM. In left-handed women, reduced integrity of the left-sided language related tracts may be closely linked to the development of right hemispheric language dominance. Our results may offer new insights into language lateralization and structure-function relationships in human language system. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Altered white matter microstructure is associated with social cognition and psychotic symptoms in 22q11.2 microdeletion syndrome

    Directory of Open Access Journals (Sweden)

    Maria eJalbrzikowski

    2014-11-01

    Full Text Available 22q11.2 Microdeletion Syndrome (22q11DS is a highly penetrant genetic mutation associated with a significantly increased risk for psychosis. Aberrant neurodevelopment may lead to inappropriate neural circuit formation and cerebral dysconnectivity in 22q11DS, which may contribute to symptom development. Here we examined: 1 differences between 22q11DS participants and typically developing controls in diffusion tensor imaging (DTI measures within white matter tracts; 2 whether there is an altered age-related trajectory of white matter pathways in 22q11DS; and 3 relationships between DTI measures, social cognition task performance and positive symptoms of psychosis in 22q11DS and typically developing controls. Sixty-four direction diffusion weighted imaging data were acquired on 65 participants (36 22q11DS, 29 controls. We examined differences between 22q11DS vs. controls in measures of fractional anisotropy (FA, axial (AD and radial diffusivity (RD, using both a voxel-based and region of interest approach. Social cognition domains assessed were: Theory of Mind and emotion recognition. Positive symptoms were assessed using the Structured Interview for Prodromal Syndromes. Compared to typically developing controls, 22q11DS participants showed significantly lower AD and RD in multiple white matter tracts, with effects of greatest magnitude for AD in the superior longitudinal fasciculus. Additionally, 22q11DS participants failed to show typical age-associated changes in FA and RD in the left inferior longitudinal fasciculus. Higher AD in the left inferior fronto-occipital fasciculus and left uncinate fasciculus was associated with better social cognition in 22q11DS and controls. In contrast, greater severity of positive symptoms was associated with lower AD in bilateral regions of the inferior fronto-occipital fasciculus in 22q11DS. White matter microstructure in tracts relevant to social cognition is disrupted in 22q11DS, and may contribute to

  18. Natural biological variation of white matter microstructure is accentuated in Huntington's disease.

    Science.gov (United States)

    Gregory, Sarah; Crawford, Helen; Seunarine, Kiran; Leavitt, Blair; Durr, Alexandra; Roos, Raymund A C; Scahill, Rachael I; Tabrizi, Sarah J; Rees, Geraint; Langbehn, Douglas; Orth, Michael

    2018-04-22

    Huntington's disease (HD) is a monogenic neurodegenerative disorder caused by a CAG-repeat expansion in the Huntingtin gene. Presence of this expansion signifies certainty of disease onset, but only partly explains age at which onset occurs. Genome-wide association studies have shown that naturally occurring genetic variability influences HD pathogenesis and disease onset. Investigating the influence of biological traits in the normal population, such as variability in white matter properties, on HD pathogenesis could provide a complementary approach to understanding disease modification. We have previously shown that while white matter diffusivity patterns in the left sensorimotor network were similar in controls and HD gene-carriers, they were more extreme in the HD group. We hypothesized that the influence of natural variation in diffusivity on effects of HD pathogenesis on white matter is not limited to the sensorimotor network but extends to cognitive, limbic, and visual networks. Using tractography, we investigated 32 bilateral pathways within HD-related networks, including motor, cognitive, and limbic, and examined diffusivity metrics using principal components analysis. We identified three independent patterns of diffusivity common to controls and HD gene-carriers that predicted HD status. The first pattern involved almost all tracts, the second was limited to sensorimotor tracts, and the third encompassed cognitive network tracts. Each diffusivity pattern was associated with network specific performance. The consistency in diffusivity patterns across both groups coupled with their association with disease status and task performance indicates that naturally-occurring patterns of diffusivity can become accentuated in the presence of the HD gene mutation to influence clinical brain function. © 2018 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

  19. Diffusion tensor imaging identifies deficits in white matter microstructure in subjects with type 1 diabetes that correlate with reduced neurocognitive function.

    Science.gov (United States)

    Kodl, Christopher T; Franc, Daniel T; Rao, Jyothi P; Anderson, Fiona S; Thomas, William; Mueller, Bryon A; Lim, Kelvin O; Seaquist, Elizabeth R

    2008-11-01

    Long-standing type 1 diabetes is associated with deficits on neurocognitive testing that suggest central white matter dysfunction. This study investigated whether diffusion tensor imaging (DTI), a type of magnetic resonance imaging that measures white matter integrity quantitatively, could identify white matter microstructural deficits in patients with long-standing type 1 diabetes and whether these differences would be associated with deficits found by neurocognitive tests. Twenty-five subjects with type 1 diabetes for at least 15 years and 25 age- and sex-matched control subjects completed DTI on a 3.0 Tesla scanner and a battery of neurocognitive tests. Fractional anisotropy was calculated for the major white matter tracts of the brain. Diabetic subjects had significantly lower mean fractional anisotropy than control subjects in the posterior corona radiata and the optic radiation (P < 0.002). In type 1 diabetic subjects, reduced fractional anisotropy correlated with poorer performance on the copy portion of the Rey-Osterreith Complex Figure Drawing Test and the Grooved Peg Board Test, both of which are believed to assess white matter function. Reduced fractional anisotropy also correlated with duration of diabetes and increased A1C. A history of severe hypoglycemia did not correlate with fractional anisotropy. DTI can detect white matter microstructural deficits in subjects with long-standing type 1 diabetes. These deficits correlate with poorer performance on selected neurocognitive tests of white matter function.

  20. The relationship between recognition memory for emotion-laden words and white matter microstructure in normal older individuals.

    Science.gov (United States)

    Saarela, Carina; Karrasch, Mira; Ilvesmäki, Tero; Parkkola, Riitta; Rinne, Juha O; Laine, Matti

    2016-12-14

    Functional neuroimaging studies have shown age-related differences in brain activation and connectivity patterns for emotional memory. Previous studies with middle-aged and older adults have reported associations between episodic memory and white matter (WM) microstructure obtained from diffusion tensor imaging, but such studies on emotional memory remain few. To our knowledge, this is the first study to explore associations between WM microstructure as measured by fractional anisotropy (FA) and recognition memory for intentionally encoded positive, negative, and emotionally neutral words using tract-based spatial statistics applied to diffusion tensor imaging images in an elderly sample (44 cognitively intact adults aged 50-79 years). The use of tract-based spatial statistics enables the identification of WM tracts important to emotional memory without a priori assumptions required for region-of-interest approaches that have been used in previous work. The behavioral analyses showed a positivity bias, that is, a preference for positive words, in recognition memory. No statistically significant associations emerged between FA and memory for negative or neutral words. Controlling for age and memory performance for negative and neutral words, recognition memory for positive words was negatively associated with FA in several projection, association, and commissural tracts in the left hemisphere. This likely reflects the complex interplay between the mnemonic positivity bias, structural WM integrity, and functional brain compensatory mechanisms in older age. Also, the unexpected directionality of the results indicates that the WM microstructural correlates of emotional memory show unique characteristics in normal older individuals.

  1. Right Fronto-Subcortical White Matter Microstructure Predicts Cognitive Control Ability on the Go/No-go Task in a Community Sample.

    Science.gov (United States)

    Hinton, Kendra E; Lahey, Benjamin B; Villalta-Gil, Victoria; Boyd, Brian D; Yvernault, Benjamin C; Werts, Katherine B; Plassard, Andrew J; Applegate, Brooks; Woodward, Neil D; Landman, Bennett A; Zald, David H

    2018-01-01

    Go/no-go tasks are widely used to index cognitive control. This construct has been linked to white matter microstructure in a circuit connecting the right inferior frontal gyrus (IFG), subthalamic nucleus (STN), and pre-supplementary motor area. However, the specificity of this association has not been tested. A general factor of white matter has been identified that is related to processing speed. Given the strong processing speed component in successful performance on the go/no-go task, this general factor could contribute to task performance, but the general factor has often not been accounted for in past studies of cognitive control. Further, studies on cognitive control have generally employed small unrepresentative case-control designs. The present study examined the relationship between go/no-go performance and white matter microstructure in a large community sample of 378 subjects that included participants with a range of both clinical and subclinical nonpsychotic psychopathology. We found that white matter microstructure properties in the right IFG-STN tract significantly predicted task performance, and remained significant after controlling for dimensional psychopathology. The general factor of white matter only reached statistical significance when controlling for dimensional psychopathology. Although the IFG-STN and general factor tracts were highly correlated, when both were included in the model, only the IFG-STN remained a significant predictor of performance. Overall, these findings suggest that while a general factor of white matter can be identified in a young community sample, white matter microstructure properties in the right IFG-STN tract show a specific relationship to cognitive control. The findings highlight the importance of examining both specific and general correlates of cognition, especially in tasks with a speeded component.

  2. Sustained attention is associated with right superior longitudinal fasciculus and superior parietal white matter microstructure in children

    DEFF Research Database (Denmark)

    Klarborg, Brith; Skak Madsen, Kathrine; Vestergaard, Martin

    2013-01-01

    Sustained attention develops during childhood and has been linked to the right fronto-parietal cortices in functional imaging studies; however, less is known about its relation to white matter (WM) characteristics. Here we investigated whether the microstructure of the WM underlying and connecting...... the right fronto-parietal cortices was associated with sustained attention performance in a group of 76 typically developing children aged 7-13 years. Sustained attention was assessed using a rapid visual information processing paradigm. The two behavioral measures of interest were the sensitivity index d......' and the coefficient of variation in reaction times (RT(CV) ). Diffusion-weighted imaging was performed. Mean fractional anisotropy (FA) was extracted from the WM underlying right dorsolateral prefrontal (DLPFC) and parietal cortex (PC), and the right superior longitudinal fasciculus (SLF), as well as equivalent...

  3. White matter microstructure in 22q11 deletion syndrome: a pilot diffusion tensor imaging and voxel-based morphometry study of children and adolescents

    NARCIS (Netherlands)

    Sundram, Frederick; Campbell, Linda E.; Azuma, Rayna; Daly, Eileen; Bloemen, Oswald J. N.; Barker, Gareth J.; Chitnis, Xavier; Jones, Derek K.; van Amelsvoort, Therese; Murphy, Kieran C.; Murphy, Declan G. M.

    2010-01-01

    Young people with 22q11 Deletion Syndrome (22q11DS) are at substantial risk for developing psychosis and have significant differences in white matter (WM) volume. However, there are few in vivo studies of both WM microstructural integrity (as measured using Diffusion Tensor (DT)-MRI) and WM volume

  4. Moderate and late preterm infants exhibit widespread brain white matter microstructure alterations at term-equivalent age relative to term-born controls

    NARCIS (Netherlands)

    Kelly, Claire E.; Cheong, Jeanie L Y; Gabra Fam, Lillian; Leemans, Alexander; Seal, Marc L.; Doyle, Lex W.; Anderson, Peter J.; Spittle, Alicia J.; Thompson, Deanne K.

    2016-01-01

    Despite the many studies documenting cerebral white matter microstructural alterations associated with very preterm birth (<32 weeks’ gestation), there is a dearth of similar research in moderate and late preterm infants (born 32–36 weeks’ gestation), who experience higher rates of

  5. The first week after concussion: Blood flow, brain function and white matter microstructure

    Directory of Open Access Journals (Sweden)

    Nathan W. Churchill

    2017-01-01

    Full Text Available Concussion is a major health concern, associated with short-term deficits in physical function, emotion and cognition, along with negative long-term health outcomes. However, we remain in the early stages of characterizing MRI markers of concussion, particularly during the first week post-injury when symptoms are most severe. In this study, 52 varsity athletes were scanned using Magnetic Resonance Imaging (MRI, including 26 athletes with acute concussion (scanned 1–7 days post-injury and 26 matched control athletes. A comprehensive set of functional and structural MRI measures were analyzed, including cerebral blood flow (CBF and global functional connectivity (Gconn of grey matter, along with fractional anisotropy (FA and mean diffusivity (MD of white matter. An analysis comparing acutely concussed athletes and controls showed limited evidence for reliable mean effects of acute concussion, with only MD showing spatially extensive differences between groups. We subsequently demonstrated that the number of days post-injury explained a significant proportion of inter-subject variability in MRI markers of acutely concussed athletes. Athletes scanned at early acute injury (1–3 days had elevated CBF and Gconn and reduced FA, but those scanned at late acute injury (5–7 days had the opposite response. In contrast, MD showed a more complex, spatially-dependent relationship with days post-injury. These novel findings highlight the variability of MRI markers during the acute phase of concussion and the critical importance of considering the acute injury time interval, which has significant implications for studies relating acute MRI data to concussion outcomes.

  6. The influence of comorbid oppositional defiant disorder on white matter microstructure in attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    van Ewijk, Hanneke; Noordermeer, Siri D S; Heslenfeld, Dirk J; Luman, Marjolein; Hartman, Catharina A; Hoekstra, Pieter J; Faraone, Stephen V; Franke, Barbara; Buitelaar, Jan K; Oosterlaan, J

    2016-07-01

    Attention-deficit/hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) are highly comorbid disorders. ADHD has been associated with altered white matter (WM) microstructure, though the literature is inconsistent, which may be due to differences in the in- or exclusion of participants with comorbid ODD. WM abnormalities in ODD are still poorly understood, and it is unclear whether comorbid ODD in ADHD may have confounded the current ADHD literature. Diffusion Tensor Imaging (DTI) was used to compare fractional anisotropy (FA) and mean diffusivity (MD) between ADHD patients with (n = 42) and without (n = 117) comorbid ODD. All participants were between 8-25 years and groups did not differ in mean age or gender. Follow-up analyses were conducted to examine the role of antisocial behaviour (conduct problems) on FA and MD values in both groups. Comorbid ODD in ADHD was associated with lower FA in left frontotemporal WM, which appeared independent of ADHD symptoms. FA was negatively associated with antisocial behaviour in ADHD + ODD, but not in ADHD-only. Comorbid ODD is associated with WM abnormalities in individuals with ADHD, which appears to be independent of ADHD symptoms. Altered WM microstructure in comorbid ODD may play a role in inconsistencies in the current DTI literature in ADHD. Altered development of these tracts may contribute to social-emotional and cognitive problems in children with oppositional and antisocial behaviour.

  7. Early microstructural white matter changes in patients with HIV: A diffusion tensor imaging study

    Directory of Open Access Journals (Sweden)

    Stubbe-Drger Bianca

    2012-05-01

    Full Text Available Abstract Background Previous studies have reported white matter (WM brain alterations in asymptomatic patients with human immunodeficiency virus (HIV. Methods We compared diffusion tensor imaging (DTI derived WM fractional anisotropy (FA between HIV-patients with and without mild macroscopic brain lesions determined using standard magnetic resonance imaging (MRI. We furthermore investigated whether WM alterations co-occurred with neurocognitive deficits and depression. We performed structural MRI and DTI for 19 patients and 19 age-matched healthy controls. Regionally-specific WM integrity was investigated using voxel-based statistics of whole-brain FA maps and region-of-interest analysis. Each patient underwent laboratory and neuropsychological tests. Results Structural MRI revealed no lesions in twelve (HIV-MRN and unspecific mild macrostructural lesions in seven patients (HIV-MRL. Both analyses revealed widespread FA-alterations in all patients. Patients with HIV-MRL had FA-alterations primarily adjacent to the observed lesions and, whilst reduced in extent, patients with HIV-MRN also exhibited FA-alterations in similar regions. Patients with evidence of depression showed FA-increase in the ventral tegmental area, pallidum and nucleus accumbens in both hemispheres, and patients with evidence of HIV-associated neurocognitive disorder showed widespread FA-reduction. Conclusion These results show that patients with HIV-MRN have evidence of FA-alterations in similar regions that are lesioned in HIV-MRL patients, suggesting common neuropathological processes. Furthermore, they suggest a biological rather than a reactive origin of depression in HIV-patients.

  8. White Matter Microstructure Predicts Autistic Traits in Attention-Deficit/Hyperactivity Disorder

    Science.gov (United States)

    Cooper, Miriam; Thapar, Anita; Jones, Derek K.

    2014-01-01

    Traits of autism spectrum disorder (ASD) in children with attention-deficit/hyperactivity disorder (ADHD) have previously been found to index clinical severity. This study examined the association of ASD traits with diffusion parameters in adolescent males with ADHD (n = 17), and also compared WM microstructure relative to controls (n = 17).…

  9. White matter microstructure predicts longitudinal social cognitive outcomes after paediatric traumatic brain injury: a diffusion tensor imaging study.

    Science.gov (United States)

    Ryan, N P; Genc, S; Beauchamp, M H; Yeates, K O; Hearps, S; Catroppa, C; Anderson, V A; Silk, T J

    2018-03-01

    Deficits in social cognition may be among the most profound and disabling sequelae of paediatric traumatic brain injury (TBI); however, the neuroanatomical correlates of longitudinal outcomes in this domain remain unexplored. This study aimed to characterize social cognitive outcomes longitudinally after paediatric TBI, and to evaluate the use of sub-acute diffusion tensor imaging (DTI) to predict these outcomes. The sample included 52 children with mild complex-severe TBI who were assessed on cognitive theory of mind (ToM), pragmatic language and affective ToM at 6- and 24-months post-injury. For comparison, 43 typically developing controls (TDCs) of similar age and sex were recruited. DTI data were acquired sub-acutely (mean = 5.5 weeks post-injury) in a subset of 65 children (TBI = 35; TDC = 30) to evaluate longitudinal prospective relationships between white matter microstructure assessed using Tract-Based Spatial Statistics and social cognitive outcomes. Whole brain voxel-wise analysis revealed significantly higher mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) in the sub-acute TBI group compared with TDC, with differences observed predominantly in the splenium of the corpus callosum (sCC), sagittal stratum (SS), dorsal cingulum (DC), uncinate fasciculus (UF) and middle and superior cerebellar peduncles (MCP & SCP, respectively). Relative to TDCs, children with TBI showed poorer cognitive ToM, affective ToM and pragmatic language at 6-months post-insult, and those deficits were related to abnormal diffusivity of the sCC, SS, DC, UF, MCP and SCP. Moreover, children with TBI showed poorer affective ToM and pragmatic language at 24-months post-injury, and those outcomes were predicted by sub-acute alterations in diffusivity of the DC and MCP. Abnormal microstructure within frontal-temporal, limbic and cerebro-cerebellar white matter may be a risk factor for long-term social difficulties observed in children with TBI. DTI may have

  10. Harmonizing DTI measurements across scanners to examine the development of white matter microstructure in 803 adolescents of the NCANDA study.

    Science.gov (United States)

    Pohl, Kilian M; Sullivan, Edith V; Rohlfing, Torsten; Chu, Weiwei; Kwon, Dongjin; Nichols, B Nolan; Zhang, Yong; Brown, Sandra A; Tapert, Susan F; Cummins, Kevin; Thompson, Wesley K; Brumback, Ty; Colrain, Ian M; Baker, Fiona C; Prouty, Devin; De Bellis, Michael D; Voyvodic, James T; Clark, Duncan B; Schirda, Claudiu; Nagel, Bonnie J; Pfefferbaum, Adolf

    2016-04-15

    Neurodevelopment continues through adolescence, with notable maturation of white matter tracts comprising regional fiber systems progressing at different rates. To identify factors that could contribute to regional differences in white matter microstructure development, large samples of youth spanning adolescence to young adulthood are essential to parse these factors. Recruitment of adequate samples generally relies on multi-site consortia but comes with the challenge of merging data acquired on different platforms. In the current study, diffusion tensor imaging (DTI) data were acquired on GE and Siemens systems through the National Consortium on Alcohol and NeuroDevelopment in Adolescence (NCANDA), a multi-site study designed to track the trajectories of regional brain development during a time of high risk for initiating alcohol consumption. This cross-sectional analysis reports baseline Tract-Based Spatial Statistic (TBSS) of regional fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (L1), and radial diffusivity (LT) from the five consortium sites on 671 adolescents who met no/low alcohol or drug consumption criteria and 132 adolescents with a history of exceeding consumption criteria. Harmonization of DTI metrics across manufacturers entailed the use of human-phantom data, acquired multiple times on each of three non-NCANDA participants at each site's MR system, to determine a manufacturer-specific correction factor. Application of the correction factor derived from human phantom data measured on MR systems from different manufacturers reduced the standard deviation of the DTI metrics for FA by almost a half, enabling harmonization of data that would have otherwise carried systematic error. Permutation testing supported the hypothesis of higher FA and lower diffusivity measures in older adolescents and indicated that, overall, the FA, MD, and L1 of the boys were higher than those of the girls, suggesting continued microstructural development

  11. White matter microstructural changes in adolescent anorexia nervosa including an exploratory longitudinal study

    Directory of Open Access Journals (Sweden)

    Katja Vogel

    2016-01-01

    Conclusions: Our findings reveal a markedly different pattern of WM microstructural changes in adolescent AN compared to most previous results in adult AN. This could signify a different susceptibility and reaction to semi-starvation in the still developing brain of adolescents or a time-dependent pathomechanism differing with extend of chronicity. Higher FA at admission in adolescents with AN could point to WM fibers being packed together more closely.

  12. ADHD severity is associated with white matter microstructure in the subgenual cingulum

    Directory of Open Access Journals (Sweden)

    Miriam Cooper

    2015-01-01

    Conclusions: Results shed light on possible anatomical correlates of ADHD severity and autistic symptoms in pathways which may be involved in the ADHD phenotype. They provide further evidence that tract-specific approaches may a reveal associations between microstructural metrics and indices of phenotypic variability which would not be detected using voxelwise approaches, and b provide improved rather than differential sensitivity compared to voxelwise approaches.

  13. Integrating retrogenesis theory to Alzheimer's disease pathology: insight from DTI-TBSS investigation of the white matter microstructural integrity.

    Science.gov (United States)

    Alves, Gilberto Sousa; Oertel Knöchel, Viola; Knöchel, Christian; Carvalho, André Férrer; Pantel, Johannes; Engelhardt, Eliasz; Laks, Jerson

    2015-01-01

    Microstructural abnormalities in white matter (WM) are often reported in Alzheimer's disease (AD) and may reflect primary or secondary circuitry degeneration (i.e., due to cortical atrophy). The interpretation of diffusion tensor imaging (DTI) eigenvectors, known as multiple indices, may provide new insights into the main pathological models supporting primary or secondary patterns of WM disruption in AD, the retrogenesis, and Wallerian degeneration models, respectively. The aim of this review is to analyze the current literature on the contribution of DTI multiple indices to the understanding of AD neuropathology, taking the retrogenesis model as a reference for discussion. A systematic review using MEDLINE, EMBASE, and PUBMED was performed. Evidence suggests that AD evolves through distinct patterns of WM disruption, in which retrogenesis or, alternatively, the Wallerian degeneration may prevail. Distinct patterns of WM atrophy may be influenced by complex interactions which comprise disease status and progression, fiber localization, concurrent risk factors (i.e., vascular disease, gender), and cognitive reserve. The use of DTI multiple indices in addition to other standard multimodal methods in dementia research may help to determine the contribution of retrogenesis hypothesis to the understanding of neuropathological hallmarks that lead to AD.

  14. Sex differences in associations between white matter microstructure and gonadal hormones in children and adolescents with prenatal alcohol exposure.

    Science.gov (United States)

    Uban, K A; Herting, M M; Wozniak, J R; Sowell, E R

    2017-09-01

    Despite accumulating evidence from animal models demonstrating that prenatal alcohol exposure (PAE) results in life-long neuroendocrine dysregulation, very little is known on this topic among humans with fetal alcohol spectrum disorders (FASD). We expected that alterations in gonadal hormones might interfere with the typical development of white matter (WM) myelination, and in a sex-dependent manner, in human adolescents with FASD. In order to investigate this hypothesis, we used diffusion tensor imaging (DTI) to assess: 1) whether or not sex moderates the impact of PAE on WM microstructure; and 2) how gonadal hormones relate to alterations in WM microstructure in children and adolescents affected by PAE. 61 youth (9 to 16 yrs.; 49% girls; 50% PAE) participated as part of the Collaborative Initiative on Fetal Alcohol Spectrum Disorders (CIFASD). DTI scans and passive drool samples were obtained to examine neurodevelopmental associations with testosterone (T) and dehydroepiandrosterone (DHEA) levels in boys and girls, and estradiol (E2) and progesterone (P) levels in girls. Tract-based spatial statistics were utilized to generate fractional anisotropy (FA) and mean diffusivity (MD) for 9 a priori WM regions of interest (ROIs). As predicted, alterations in FA were observed in adolescents with PAE relative to controls, and these differences varied by sex. Girls with PAE exhibited lower FA (Inferior fronto-occipital and Uncinate fasciculi) while boys with PAE exhibited higher FA (Callosal body, Cingulum, Corticospinal tract, Optic radiation, Superior longitudinal fasciculus) relative to age-matched controls. When gonadal hormone levels were examined in relation to DTI measures, additional group differences in FA were revealed, demonstrating that neuroendocrine factors are associated with PAE-related brain alterations. These findings provide human evidence that PAE relates to sex-specific differences in WM microstructure, and underlying alterations in gonadal hormone

  15. White Matter Microstructural Compromise Is Associated With Cognition But Not Posttraumatic Stress Disorder Symptoms in Military Veterans With Traumatic Brain Injury.

    Science.gov (United States)

    Sorg, Scott F; Schiehser, Dawn M; Bondi, Mark W; Luc, Norman; Clark, Alexandra L; Jacobson, Mark W; Frank, Lawrence R; Delano-Wood, Lisa

    2016-01-01

    To investigate white matter microstructure compromise in Veterans with a history of traumatic brain injury (TBI) and its possible contribution to posttraumatic stress disorder (PTSD) symptomatology and neuropsychological functioning via diffusion tensor imaging. Thirty-eight Veterans with mild (n = 33) and moderate (n = 5) TBI and 17 military control participants without TBI completed neuropsychological testing and psychiatric screening and underwent magnetic resonance imaging an average of 4 years following their TBI event(s). Fractional anisotropy (FA) and diffusivity measures were extracted from 9 white matter tracts. Compared with military control participants, TBI participants reported higher levels of PTSD symptoms and performed worse on measures of memory and psychomotor-processing speed. Traumatic brain injury was associated with lower FA in the genu of the corpus callosum and left cingulum bundle. Fractional anisotropy negatively correlated with processing speed and/or executive functions in 7 of the 8 tracts. Regional FA did not correlate with memory or PTSD symptom ratings. Results suggest that current PTSD symptoms are independent of TBI-related white matter alterations, as measured by diffusion tensor imaging. In addition, white matter microstructural compromise may contribute to reduced processing speed in our sample of participants with history of neurotrauma. Findings of the current study add insight into the factors associated with complicated recovery from mild to moderate TBI.

  16. Diseases of white matter

    International Nuclear Information System (INIS)

    Holland, B.A.

    1987-01-01

    The diagnosis of white matter abnormalities was revolutionized by the advent of computed tomography (CT), which provided a noninvasive method of detection and assessment of progression of a variety of white matter processes. However, the inadequacies of CT were recognized early, including its relative insensitivity to small foci of abnormal myelin in the brain when correlated with autopsy findings and its inability to image directly white matter diseases of the spinal cord. Magnetic resonance imaging (MRI), on the other hand, sensitive to the slight difference in tissue composition of normal gray and white matter and to subtle increase in water content associated with myelin disorders, is uniquely suited for the examination of white matter pathology. Its clinical applications include the evaluation of the normal process of myelination in childhood and the various white matter diseases, including disorders of demyelination and dysmyelination

  17. Progressive white matter microstructure damage in male chronic heroin dependent individuals: a DTI and TBSS study.

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    Yingwei Qiu

    Full Text Available BACKGROUND: To investigate the WM microstructure deficits in heroin dependent individuals (HDIs with different length of heroin dependence, and to investigate whether these WM deficits can be related to the duration of heroin use and to decision-making deficits in HDIs. METHODOLOGY/PRINCIPAL FINDINGS: Thirty-six HDIs [including eighteen sHDIs (duration of heroin dependent is less than 10 years and eighteen lHDIs (duration of dependent is between 10:20 years] and sixteen healthy controls participated in this study. Whole brain voxel-wise analysis of fractional anisotropy (FA, mean diffusivity (MD, axial diffusivity (Da and radial diffusivity (Dr were performed by tract-based spatial statistics (TBSS to localize abnormal WM regions among groups. TBSS demonstrated that sHDIs had significantly lower FA than controls in right orbito-frontal WM, bilateral temporal WM and right parietal WM. The lHDIs had significantly lower FA throughout the brain compared with the controls and sHDIs. The lHDIs had significantly lower Da than controls in bilateral inferior frontaloccipital fasciculus, bilateral splenium of corpus callosum, left inferior longitudinal fasciculus, and had significantly higher Dr than controls in bilateral uncinatus fasciculus, bilateral inferior frontaloccipital fasciculus and bilateral cortical spinal fasciculus. Volume-of-interest (VOI analyses detect the changes of diffusivity indices in the regions with FA abnormalities revealed by control vs sHDIs. In most VOIs, FA reductions were caused by the increase in Dr as well as the decrease in Da. Correlation analysis was used to assess the relationship between FA and behavioral measures in HDIs and controls available. Significantly positively correlations were found between the FA values in the right orbital-frontal WM, right parietal WM and IGT performance. CONCLUSIONS: The extent and severity of WM integrity deficits in HDIs was associated with the length of heroin dependent. Furthermore

  18. Microstructural analysis of human white matter architecture using Polarized Light Imaging (PLI: Views from neuroanatomy

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    Hubertus eAxer

    2011-11-01

    Full Text Available To date, there are several methods for mapping connectivity, ranging from the macroscopic to molecular scales. However, it is difficult to integrate this multiply-scaled data into one concept. Polarized light imaging (PLI is a method to quantify fiber orientation in gross histological brain sections based on the birefringent properties of the myelin sheaths. The method is capable of imaging fiber orientation of larger-scale architectural patterns with higher detail than diffusion MRI of the human brain. PLI analyses light transmission through a gross histological section of a human brain under rotation of a polarization filter combination. Estimates of the angle of fiber direction and the angle of fiber inclination are automatically calculated at every point of the imaged section. Multiple sections can be assembled into a 3D volume. We describe the principles of PLI and present several studies of fiber anatomy in the human brain: 6 brainstems were serially sectioned, imaged with PLI, and 3D reconstructed. Pyramidal tract and lemniscus medialis were segmented in the PLI datasets. PLI data from the internal capsule was related to results from confocal laser scanning microscopy, which is a method of smaller scale fiber anatomy. PLI fiber architecture of the extreme capsule was compared to macroscopical dissection, which represents a method of larger scale anatomy. The microstructure of the anterior human cingulum bundle was analyzed in serial sections of 6 human brains. PLI can generate highly-resolved 3D datsets of fiber orientation of the human brain and has, therefore, a high comparability to diffusion MR. To get additional information regarding axon structure and density, PLI can also be combined with classical histological stains. It brings the directional aspects of diffusion MRI into the range of histology and may represent a promising tool to close the gap between larger scale diffusion orientation and microstructural histological analysis

  19. Links between white matter microstructure and cortisol reactivity to stress in early childhood: Evidence for moderation by parenting

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    Haroon I. Sheikh

    2014-01-01

    Full Text Available Activity of the hypothalamic–pituitary–adrenal axis (measured via cortisol reactivity may be a biological marker of risk for depression and anxiety, possibly even early in development. However, the structural neural correlates of early cortisol reactivity are not well known, although these would potentially inform broader models of mechanisms of risk, especially if the early environment further shapes these relationships. Therefore, we examined links between white matter architecture and young girls' cortisol reactivity and whether early caregiving moderated these links. We recruited 45 6-year-old girls based on whether they had previously shown high or low cortisol reactivity to a stress task at age 3. White matter integrity was assessed by calculating fractional anisotropy (FA of diffusion-weighted magnetic resonance imaging scans. Parenting styles were measured via a standardized parent–child interaction task. Significant associations were found between FA in white matter regions adjacent to the left thalamus, the right anterior cingulate cortex, and the right superior frontal gyrus (all ps < .001. Further, positive early caregiving moderated the effect of high cortisol reactivity on white matter FA (all ps ≤ .05, with high stress reactive girls who received greater parent positive affect showing white matter structure more similar to that of low stress reactive girls. Results show associations between white matter integrity of various limbic regions of the brain and early cortisol reactivity to stress and provide preliminary support for the notion that parenting may moderate associations.

  20. Altered white matter microstructure associated with mild and moderate depressive symptoms in young adults, a diffusion tensor imaging study.

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    Ghazi Sherbaf, Farzaneh; Same, Kaveh; Ashraf-Ganjouei, Amir; Aarabi, Mohammad H

    2018-05-23

    In the context of growing evidence supporting disturbed neural connectivity in the pathogenesis of depressive symptoms, we used the diffusion tensor imaging technique to investigate white matter disruptions in previously undiagnosed and hence treatment-naive young adults with mild and moderate depressive symptoms screened by Beck's Depression Inventory test compared with age-matched and sex-matched healthy controls. This is the first diffusion tensor imaging study to assess minor forms of depression. We hypothesized that subthreshold depressive symptoms share the same neural disruptions as major depressive disorder (MDD). Each group included 47 participants with a mean age of 20.1±1.1 years. The exploratory region of interest method was used to assess integrity (fractional anisotropy and mean diffusivity) in 48 regions of the brain based on Mori atlas. Data were recruited from the Southwest University Longitudinal Imaging Multimodal Brain Data Repository. The following pathways showed significant microstructural changes by means of reduced fractional anisotropy in the group with depressive symptoms compared with normal participants: pontine crossing tract; genu of the corpus callosum; posterior limb of the internal capsule (bilaterally); and anterior, posterior, and superior corona radiata (bilaterally). None of the above regions, but the middle cerebellar peduncle and the right superior fronto-occipital fasciculus were shown to differ significantly in the mean diffusivity values between the two groups. On the basis of the current results, our findings provide evidence that the white matter impairments in the interhemispheric connections and frontal-subcortical neural circuits may play a key role in the pathogenesis of depression in young adults. The similarity of neural underpinnings in MDD and minor depressive disorder in this study further proves that these two mood disorders exist in a continuum, and milder depressive symptoms can herald a major episode

  1. Links between white matter microstructure and cortisol reactivity to stress in early childhood: evidence for moderation by parenting.

    Science.gov (United States)

    Sheikh, Haroon I; Joanisse, Marc F; Mackrell, Sarah M; Kryski, Katie R; Smith, Heather J; Singh, Shiva M; Hayden, Elizabeth P

    2014-01-01

    Activity of the hypothalamic-pituitary-adrenal axis (measured via cortisol reactivity) may be a biological marker of risk for depression and anxiety, possibly even early in development. However, the structural neural correlates of early cortisol reactivity are not well known, although these would potentially inform broader models of mechanisms of risk, especially if the early environment further shapes these relationships. Therefore, we examined links between white matter architecture and young girls' cortisol reactivity and whether early caregiving moderated these links. We recruited 45 6-year-old girls based on whether they had previously shown high or low cortisol reactivity to a stress task at age 3. White matter integrity was assessed by calculating fractional anisotropy (FA) of diffusion-weighted magnetic resonance imaging scans. Parenting styles were measured via a standardized parent-child interaction task. Significant associations were found between FA in white matter regions adjacent to the left thalamus, the right anterior cingulate cortex, and the right superior frontal gyrus (all ps parent positive affect showing white matter structure more similar to that of low stress reactive girls. Results show associations between white matter integrity of various limbic regions of the brain and early cortisol reactivity to stress and provide preliminary support for the notion that parenting may moderate associations.

  2. TVA–based assessment of attentional capacities – associations with age and indices of brain white matter microstructure

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    Thomas eEspeseth

    2014-10-01

    Full Text Available In this study the primary aims were to characterize the effects of age on basic components of visual attention derived from assessments based on a theory of visual attention (TVA in 325 healthy volunteers covering the adult lifespan (19-81 years. Furthermore, we aimed to investigate how age-related differences on TVA parameters are associated with white matter (WM microstructure as indexed by diffusion tensor imaging (DTI. Finally, we explored how TVA parameter estimates were associated with complex, or multicomponent indices of processing speed (Digit-symbol substitution, DSS and fluid intelligence (gF. The results indicated that the TVA parameters for visual short-term memory capacity, K, and for attentional selectivity, α, were most strongly associated with age before the age of 50. However, in this age range, it was the parameter for processing speed, C, that was most clearly associated with DTI indices, in this case fractional anisotropy (FA, particularly in the genu and body of the corpus callosum. Furthermore, differences in the C parameter partially mediated differences in DSS within this age range. After the age of 50, the TVA parameter for the perceptual threshold, t0, as well as K, were most strongly related to participant age. Both parameters, but t0 more strongly so than K, were associated WM diffusivity, particularly in projection fibers such as the internal capsule, the sagittal stratum, and the corona radiata. Within this age range, t0 partially mediated age-related differences in gF. The results are consistent with, and provide novel empirical support for the neuroanatomical localization of TVA computations as outlined in the neuronal interpretation of TVA (NTVA. Furthermore, the results indicate that to understand the biological sources of age-related changes in processing speed and fluid cognition, it may be useful to employ methods that allow for computational fractionation of these multicomponent measures.

  3. White matter microstructure within the superior longitudinal fasciculus modulates the degree of response conflict indexed by N2 in healthy adults.

    Science.gov (United States)

    Gao, Shudan; Liu, Peng; Guo, Jialu; Zhu, Yuanqiang; Liu, Peng; Sun, Jinbo; Yang, Xuejuan; Qin, Wei

    2017-12-01

    Response conflict can be induced by priming multiple responses competing for control of action in trials. The N2 is one functionally-related cognitive control index for response conflict. And yet the underlying whiter matter neural substrates of inter-individual difference in conflict N2 remain unclear. So the aim of present study was to address the white matter microstructure of the N2 responsible for conflict by directly relating the amplitude cost of the event-related potential (ERP) N2 component to diffusion tensor imaging (DTI) indices in healthy subjects. Thirty healthy subjects underwent DTI scanning and electrophysiology recording during a modified Flanker task. N2 was a stimulus-locked negative ERP component. Fractional anisotropy (FA) was calculated based on DTI measures and was assumed to reflect the integrity of myelinate fiber bundles. Therefore, we tested the relationship between N2 amplitude and FA in brain white matter. Results showed that FA, an index for white matter characteristics, in the right superior longitudinal fasciculus (SLF) was significantly positively associated with N2 amplitude cost. The N2 amplitude cost also predicted response time (RT) cost in the Flanker task. Higher FA was associated with larger N2 amplitude cost, suggesting that changes in white matter integrity in the SLF may account for changes in efficient transmission of fronto-parietal modulatory conflict signals. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Smoking and the Developing Brain : Altered White Matter Microstructure in Attention-Deficit/Hyperactivity Disorder and Healthy Controls

    NARCIS (Netherlands)

    van Ewijk, Hanneke; Groenman, Annabeth P.; Zwiers, Marcel P.; Heslenfeld, Dirk J.; Faraone, Stephen V.; Hartman, Catharina A.; Luman, Marjolein; Greven, Corina U.; Hoekstra, Pieter J.; Franke, Barbara; Buitelaar, Jan; Oosterlaan, Jaap

    Brain white matter (WM) tracts, playing a vital role in the communication between brain regions, undergo important maturational changes during adolescence and young adulthood, a critical period for the development of nicotine dependence. Attention-deficit/hyperactivity disorder (ADHD) is associated

  5. Cortico-cortical white matter motor pathway microstructure is related to psychomotor retardation in major depressive disorder.

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    Tobias Bracht

    Full Text Available Alterations of brain structure and function have been associated with psychomotor retardation in major depressive disorder (MDD. However, the association of motor behaviour and white matter integrity of motor pathways in MDD is unclear. The aim of the present study was to first investigate structural connectivity of white matter motor pathways in MDD. Second, we explore the relation of objectively measured motor activity and white matter integrity of motor pathways in MDD. Therefore, 21 patients with MDD and 21 healthy controls matched for age, gender, education and body mass index underwent diffusion tensor imaging and 24 hour actigraphy (measure of the activity level the same day. Applying a probabilistic fibre tracking approach we extracted connection pathways between the dorsolateral prefrontal cortex (dlPFC, the rostral anterior cingulate cortex (rACC, the pre-supplementary motor area (pre-SMA, the SMA-proper, the primary motor cortex (M1, the caudate nucleus, the putamen, the pallidum and the thalamus. Patients had lower activity levels and demonstrated increased mean diffusivity (MD in pathways linking left pre-SMA and SMA-proper, and right SMA-proper and M1. Exploratory analyses point to a positive association of activity level and mean-fractional anisotropy in the right rACC-pre-SMA connection in MDD. Only MDD patients with low activity levels had a negative linear association of activity level and mean-MD in the left dlPFC-pre-SMA connection. Our results point to structural alterations of cortico-cortical white matter motor pathways in MDD. Altered white matter organisation of rACC-pre-SMA and dlPFC-pre-SMA pathways may contribute to movement initiation in MDD.

  6. White matter microstructural damage in small vessel disease is associated with Montreal cognitive assessment but not with mini mental state examination performances: vascular mild cognitive impairment Tuscany study.

    Science.gov (United States)

    Pasi, Marco; Salvadori, Emilia; Poggesi, Anna; Ciolli, Laura; Del Bene, Alessandra; Marini, Sandro; Nannucci, Serena; Pescini, Francesca; Valenti, Raffaella; Ginestroni, Andrea; Toschi, Nicola; Diciotti, Stefano; Mascalchi, Mario; Inzitari, Domenico; Pantoni, Leonardo

    2015-01-01

    Montreal Cognitive Assessment (MoCA) has been proposed as a screening tool in vascular cognitive impairment. Diffusion tensor imaging is sensitive to white matter microstructural damage. We investigated if diffusion tensor imaging-derived indices are more strongly associated with performances on MoCA or on the widely used mini mental state examination in patients with mild cognitive impairment and small vessel disease. Mild cognitive impairment patients with moderate/severe degrees of white matter hyperintensities on MRI were enrolled. Lacunar infarcts, cortical atrophy, medial temporal lobe atrophy and median values of mean diffusivity and fractional anisotropy of the cerebral white matter were studied and correlated with cognitive tests performances. Seventy-six patients (mean age 75.1±6.8 years, mean years of education 8.0±4.3) were assessed. In univariate analyses, a significant association of both MoCA and mini mental state examination scores with age, education, cortical atrophy, and medial temporal lobe atrophy was found, whereas mean diffusivity and fractional anisotropy were associated with MoCA. In partial correlation analyses, adjusting for all demographic and neuroimaging variables, both mean diffusivity and fractional anisotropy were associated only with MoCA (mean diffusivity: r= -0.275, P=0.023; fractional anisotropy: r=0.246, P=0.043). In patients with mild cognitive impairment and small vessel disease, diffusion tensor imaging-measured white matter microstructural damage is more related to MoCA than mini mental state examination performances. MoCA is suited for the cognitive screening of patients with small vessel disease. © 2014 American Heart Association, Inc.

  7. Highways of the emotional intellect: white matter microstructural correlates of an ability-based measure of emotional intelligence.

    Science.gov (United States)

    Pisner, Derek A; Smith, Ryan; Alkozei, Anna; Klimova, Aleksandra; Killgore, William D S

    2017-06-01

    Individuals differ in their ability to understand emotional information and apply that understanding to make decisions and solve problems effectively - a construct known as Emotional Intelligence (EI). While considerable evidence supports the importance of EI in social and occupational functioning, the neural underpinnings of this capacity are relatively unexplored. We used Tract-Based Spatial Statistics (TBSS) to determine the white matter correlates of EI as measured by the ability-based Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT). Participants included 32 healthy adults (16 men; 16 women), aged 18-45 years. White matter integrity in key tracts was positively correlated with the Strategic Area branches of the MSCEIT (Understanding Emotions and Managing Emotions), but not the Experiential branches (Perceiving and Facilitating Emotions). Specifically, the Understanding Emotions branch was associated with greater fractional anisotropy (FA) within somatosensory and sensory-motor fiber bundles, particularly those of the left superior longitudinal fasciculus and corticospinal tract. Managing Emotions was associated with greater FA within frontal-affective association tracts including the anterior forceps and right uncinate fasciculus, along with frontal-parietal cingulum and interhemispheric corpus callosum tracts. These findings suggest that specific components of EI are directly related to the structural microarchitecture of major axonal pathways.

  8. Cerebral white matter hypoplasia

    International Nuclear Information System (INIS)

    Dietrich, R.B.; Shields, W.D.; Sankar, R.

    1990-01-01

    This paper demonstrates the MR imaging findings in children with cerebral white matter hypoplasia (CWMH). The MR studies of four children, aged 3-7 y (mean age, 2.3 y) with a diagnosis of CWMH were reviewed. In all cases multiplanar T1-weighted and T2-weighted spin-echo images were obtained. All children had similar histories of severe developmental delay and nonprogressive neurologic deficits despite normal gestational and birth histories. In two cases there was a history of maternal cocaine abuse. Autopsy correlation was available in one child. The MR images of all four children demonstrated diffuse lack of white matter and enlarged ventricles but normal-appearing gray matter. The corpus callosum, although completely formed, was severely thinned. There was no evidence of gliosis or porencephaly, and the distribution of myelin deposition was normal for age in all cases. Autopsy finding in one child correlated exactly with the MR finding

  9. The effects of mild germinal matrix-intraventricular haemorrhage on the developmental white matter microstructure of preterm neonates. A DTI study

    International Nuclear Information System (INIS)

    Tortora, Domenico; Martinetti, Carola; Severino, Mariasavina; Morana, Giovanni; Rossi, Andrea; Uccella, Sara; Brera, Fabia; Malova, Mariya; Parodi, Alessandro; Ramenghi, Luca Antonio

    2018-01-01

    To evaluate white matter (WM) microstructural changes in preterm neonates (PN) with mild germinal matrix-intraventricular haemorrhage (mGMH-IVH) (grades I and II) and no other associated MRI abnormalities, and correlate them with gestational age (GA) and neurodevelopmental outcome. Tract-based spatial-statistics (TBSS) was performed on DTI of 103 patients studied at term-equivalent age, to compare diffusional parameters (fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), axial diffusivity (AD)) between mGMH-IVH neonates (24/103) and controls matched by GA at birth and sex. The relationship between DTI abnormalities, GA and neurodevelopmental outcome assessed with Griffiths' Developmental Scale-Revised:0-2 was explored using TBSS and Spearman-correlation analysis (p <.05). Affected neonates had lower FA, higher RD and MD of the corpus callosum, limbic pathways and cerebellar tracts. Extremely preterm neonates (GA < 29 weeks) presented more severe microstructural impairment (higher RD and MD) in periventricular regions. Neonates of GA ≥ 29 weeks had milder WM alterations (lower FA), also in subcortical WM. DTI abnormalities were associated with poorer locomotor, eye-hand coordination and performance outcomes at 24 months. WM microstructural changes occur in PN with mGMH-IVH with a GA-dependent selective vulnerability of WM regions, and correlate with adverse neurodevelopmental outcome at 24 months. (orig.)

  10. Surface-based vertexwise analysis of morphometry and microstructural integrity for white matter tracts in diffusion tensor imaging: With application to the corpus callosum in Alzheimer's disease.

    Science.gov (United States)

    Tang, Xiaoying; Qin, Yuanyuan; Zhu, Wenzhen; Miller, Michael I

    2017-04-01

    In this article, we present a unified statistical pipeline for analyzing the white matter (WM) tracts morphometry and microstructural integrity, both globally and locally within the same WM tract, from diffusion tensor imaging. Morphometry is quantified globally by the volumetric measurement and locally by the vertexwise surface areas. Meanwhile, microstructural integrity is quantified globally by the mean fractional anisotropy (FA) and trace values within the specific WM tract and locally by the FA and trace values defined at each vertex of its bounding surface. The proposed pipeline consists of four steps: (1) fully automated segmentation of WM tracts in a multi-contrast multi-atlas framework; (2) generation of the smooth surface representations for the WM tracts of interest; (3) common template surface generation on which the localized morphometric and microstructural statistics are defined and a variety of statistical analyses can be conducted; (4) multiple comparison correction to determine the significance of the statistical analysis results. Detailed herein, this pipeline has been applied to the corpus callosum in Alzheimer's disease (AD) with significantly decreased FA values and increased trace values, both globally and locally, being detected in patients with AD when compared to normal aging populations. A subdivision of the corpus callosum in both hemispheres revealed that the AD pathology primarily affects the body and splenium of the corpus callosum. Validation analyses and two multiple comparison correction strategies are provided. Hum Brain Mapp 38:1875-1893, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  11. The effects of mild germinal matrix-intraventricular haemorrhage on the developmental white matter microstructure of preterm neonates. A DTI study

    Energy Technology Data Exchange (ETDEWEB)

    Tortora, Domenico; Martinetti, Carola; Severino, Mariasavina; Morana, Giovanni; Rossi, Andrea [Istituto Giannina Gaslini, Neuroradiology Unit, Genoa (Italy); Uccella, Sara; Brera, Fabia [Istituto Giannina Gaslini, Neuropsychiatry Unit, Genoa (Italy); Malova, Mariya; Parodi, Alessandro; Ramenghi, Luca Antonio [Istituto Giannina Gaslini, Neonatal Intensive Care Unit, Genoa (Italy)

    2018-03-15

    To evaluate white matter (WM) microstructural changes in preterm neonates (PN) with mild germinal matrix-intraventricular haemorrhage (mGMH-IVH) (grades I and II) and no other associated MRI abnormalities, and correlate them with gestational age (GA) and neurodevelopmental outcome. Tract-based spatial-statistics (TBSS) was performed on DTI of 103 patients studied at term-equivalent age, to compare diffusional parameters (fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), axial diffusivity (AD)) between mGMH-IVH neonates (24/103) and controls matched by GA at birth and sex. The relationship between DTI abnormalities, GA and neurodevelopmental outcome assessed with Griffiths' Developmental Scale-Revised:0-2 was explored using TBSS and Spearman-correlation analysis (p <.05). Affected neonates had lower FA, higher RD and MD of the corpus callosum, limbic pathways and cerebellar tracts. Extremely preterm neonates (GA < 29 weeks) presented more severe microstructural impairment (higher RD and MD) in periventricular regions. Neonates of GA ≥ 29 weeks had milder WM alterations (lower FA), also in subcortical WM. DTI abnormalities were associated with poorer locomotor, eye-hand coordination and performance outcomes at 24 months. WM microstructural changes occur in PN with mGMH-IVH with a GA-dependent selective vulnerability of WM regions, and correlate with adverse neurodevelopmental outcome at 24 months. (orig.)

  12. Functional activity and white matter microstructure reveal the independent effects of age of acquisition and proficiency on second-language learning.

    Science.gov (United States)

    Nichols, Emily S; Joanisse, Marc F

    2016-12-01

    Two key factors govern how bilingual speakers neurally maintain two languages: the speakers' second language age of acquisition (AoA) and their subsequent proficiency. However, the relative roles of these two factors have been difficult to disentangle given that the two can be closely correlated, and most prior studies have examined the two factors in isolation. Here, we combine functional magnetic resonance imaging with diffusion tensor imaging to identify specific brain areas that are independently modulated by AoA and proficiency in second language speakers. First-language Mandarin Chinese speakers who are second language speakers of English were scanned as they performed a picture-word matching task in either language. In the same session we also acquired diffusion-weighted scans to assess white matter microstructure, along with behavioural measures of language proficiency prior to entering the scanner. Results reveal gray- and white-matter networks involving both the left and right hemisphere that independently vary as a function of a second-language speaker's AoA and proficiency, focused on the superior temporal gyrus, middle and inferior frontal gyrus, parahippocampal gyrus, and the basal ganglia. These results indicate that proficiency and AoA explain separate functional and structural networks in the bilingual brain, which we interpret as suggesting distinct types of plasticity for age-dependent effects (i.e., AoA) versus experience and/or predisposition (i.e., proficiency). Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  13. Lower white matter microstructure in the superior longitudinal fasciculus is associated with increased response time variability in adults with attention-deficit/ hyperactivity disorder.

    Science.gov (United States)

    Wolfers, Thomas; Onnink, A Marten H; Zwiers, Marcel P; Arias-Vasquez, Alejandro; Hoogman, Martine; Mostert, Jeanette C; Kan, Cornelis C; Slaats-Willemse, Dorine; Buitelaar, Jan K; Franke, Barbara

    2015-09-01

    Response time variability (RTV) is consistently increased in patients with attention-deficit/hyperactivity disorder (ADHD). A right-hemispheric frontoparietal attention network model has been implicated in these patients. The 3 main connecting fibre tracts in this network, the superior longitudinal fasciculus (SLF), inferior longitudinal fasciculus (ILF) and the cingulum bundle (CB), show microstructural abnormalities in patients with ADHD. We hypothesized that the microstructural integrity of the 3 white matter tracts of this network are associated with ADHD and RTV. We examined RTV in adults with ADHD by modelling the reaction time distribution as an exponentially modified Gaussian (ex-Gaussian) function with the parameters μ, σ and τ, the latter of which has been attributed to lapses of attention. We assessed adults with ADHD and healthy controls using a sustained attention task. Diffusion tensor imaging-derived fractional anisotropy (FA) values were determined to quantify bilateral microstructural integrity of the tracts of interest. We included 100 adults with ADHD and 96 controls in our study. Increased τ was associated with ADHD diagnosis and was linked to symptoms of inattention. An inverse correlation of τ with mean FA was seen in the right SLF of patients with ADHD, but no direct association between the mean FA of the 6 regions of interest with ADHD could be observed. Regions of interest were defined a priori based on the attentional network model for ADHD and thus we might have missed effects in other networks. This study suggests that reduced microstructural integrity of the right SLF is associated with elevated τ in patients with ADHD.

  14. Relationship between Stereoscopic Vision, Visual Perception, and Microstructure Changes of Corpus Callosum and Occipital White Matter in the 4-Year-Old Very Low Birth Weight Children

    Directory of Open Access Journals (Sweden)

    Przemko Kwinta

    2015-01-01

    Full Text Available Aim. To assess the relationship between stereoscopic vision, visual perception, and microstructure of the corpus callosum (CC and occipital white matter, 61 children born with a mean birth weight of 1024 g (SD 270 g were subjected to detailed ophthalmologic evaluation, Developmental Test of Visual Perception (DTVP-3, and diffusion tensor imaging (DTI at the age of 4. Results. Abnormal stereoscopic vision was detected in 16 children. Children with abnormal stereoscopic vision had smaller CC (CC length: 53±6 mm versus 61±4 mm; p<0.01; estimated CC area: 314±106 mm2 versus 446±79 mm2; p<0.01 and lower fractional anisotropy (FA values in CC (FA value of rostrum/genu: 0.7±0.09 versus 0.79±0.07; p<0.01; FA value of CC body: 0.74±0.13 versus 0.82±0.09; p=0.03. We found a significant correlation between DTVP-3 scores, CC size, and FA values in rostrum and body. This correlation was unrelated to retinopathy of prematurity. Conclusions. Visual perceptive dysfunction in ex-preterm children without major sequelae of prematurity depends on more subtle changes in the brain microstructure, including CC. Role of interhemispheric connections in visual perception might be more complex than previously anticipated.

  15. Spaceflight Effect on White Matter Structural Integrity

    Science.gov (United States)

    Lee, Jessica K.; Kopplemans, Vincent; Paternack, Ofer; Bloomberg, Jacob J.; Mulavara, Ajitkumar P.; Seidler, Rachael D.

    2017-01-01

    Recent reports of elevated brain white matter hyperintensity (WMH) counts and volume in postflight astronaut MRIs suggest that further examination of spaceflight's impact on the microstructure of brain white matter is warranted. To this end, retrospective longitudinal diffusion-weighted MRI scans obtained from 15 astronauts were evaluated. In light of the recent reports of microgravity-induced cephalad fluid shift and gray matter atrophy seen in astronauts, we applied a technique to estimate diffusion tensor imaging (DTI) metrics corrected for free water contamination. This approach enabled the analysis of white matter tissue-specific alterations that are unrelated to fluid shifts, occurring from before spaceflight to after landing. After spaceflight, decreased fractional anisotropy (FA) values were detected in an area encompassing the superior and inferior longitudinal fasciculi and the inferior fronto-occipital fasciculus. Increased radial diffusivity (RD) and decreased axial diffusivity (AD) were also detected within overlapping regions. In addition, FA values in the corticospinal tract decreased and RD measures in the precentral gyrus white matter increased from before to after flight. The results show disrupted structural connectivity of white matter in tracts involved in visuospatial processing, vestibular function, and movement control as a result of spaceflight. The findings may help us understand the structural underpinnings of the extensive spaceflight-induced sensorimotor remodeling. Prospective longitudinal assessment of the white matter integrity in astronauts is needed to characterize the evolution of white matter microstructural changes associated with spaceflight, their behavioral consequences, and the time course of recovery. Supported by a grant from the National Space Biomedical Research Institute, NASA NCC 9-58.

  16. Synchronous changes of cortical thickness and corresponding white matter microstructure during brain development accessed by diffusion MRI tractography from parcellated cortex

    Directory of Open Access Journals (Sweden)

    Tina eJeon

    2015-12-01

    Full Text Available Cortical thickness (CT changes during normal brain development is associated with complicated cellular and molecular processes including synaptic pruning and apoptosis. In parallel, the microstructural enhancement of developmental white matter (WM axons with their neuronal bodies in the cerebral cortex has been widely reported with measurements of metrics derived from diffusion tensor imaging (DTI, especially fractional anisotropy (FA. We hypothesized that the changes of CT and microstructural enhancement of corresponding axons are highly interacted during development. DTI and T1-weighted images of 50 healthy children and adolescents between the ages of 7 to 25 years were acquired. With the parcellated cortical gyri transformed from T1-weighted images to DTI space as the tractography seeds, probabilistic tracking was performed to delineate the WM fibers traced from specific parcellated cortical regions. CT was measured at certain cortical regions and FA was measured from the WM fibers traced from same cortical regions. The CT of all frontal cortical gyri, includeing Brodmann areas 4, 6, 8, 9, 10, 11, 44, 45, 46 and 47, decreased significantly and heterogeneously; concurrently, significant and heterogeneous increases of FA of WM traced from corresponding regions were found. We further revealed significant correlation between the slopes of the CT decrease and the slopes of corresponding WM FA increase in all frontal cortical gyri, suggesting coherent cortical pruning and corresponding WM microstructural enhancement. Such correlation was not found in cortical regions other than frontal cortex. The molecular and cellular mechanisms of these synchronous changes may be associated with overlapping signaling pathways of axonal guidance, synaptic pruning, neuronal apoptosis and more prevalent interstitial neurons in the prefrontal cortex. Revealing the coherence of cortical and WM structural changes during development may open a new window for

  17. Alterations in white matter microstructure as vulnerability factors and acquired signs of traffic accident-induced PTSD.

    Directory of Open Access Journals (Sweden)

    Yawen Sun

    Full Text Available It remains unclear whether white matter (WM changes found in post-traumatic stress disorder (PTSD patients are stress-induced or precursors for vulnerability. The current study aimed to identify susceptibility factors relating to the development of PTSD and to examine the ability of these factors to predict the course of longitudinal PTSD. Sixty two victims who had experienced traffic accidents underwent diffusion tensor imaging using a 3.0T MRI system within 2 days after their accidents. Of these, 21 were diagnosed with PTSD at 1 or 6 months using the Clinician-Administered Ptsd Scale (CAPS. Then, 11 trauma-exposed victims with PTSD underwent the second MRI scan. Compared with the victims without PTSD, the victims with PTSD showed decreased fractional anisotropy (FA in WM of the anterior cingulate cortex, ventromedial prefrontal cortex (vmPFC, temporal lobes and midbrain, and increased mean diffusivity (MD in the vmPFC within 2 days after the traumatic event. Importantly, decreased FA of the vmPFC in the acute phase predicted greater future CAPS scores. In addition, we found decreased FA in the insula in the follow-up scan in the victims with PTSD, which correlated with the decreased FA of the vmPFC in their baseline scan. These results suggested that the WM might have changed within 2 days after the traumatic event in the individuals who would later develop PTSD. Furthermore, decreased FA of the vmPFC could be a possible vulnerability marker predicting future development of PTSD and may provide an outcome prediction of the acquired signs.

  18. Microstructure changes of occipital white matter are responsible for visual problems in the 3–4-year-old very low birth weight children

    Directory of Open Access Journals (Sweden)

    Anna Lesniak

    2017-01-01

    Full Text Available Purpose: The main aim of the study was to evaluate which factors affect the long-time visual function in preterm children, whether it is prematurity or retinopathy of prematurity or perhaps disturbances in the visual pathway. Materials and Methods: Fifty-eight children with mean birth weight 1016 g (range 520–1500 g were evaluated at mean age 48 months (range 42–54 months. All children underwent magnetic resonance imaging (MRI studies, visual evoked potentials (VEPs, and the Developmental Test of Visual Perception (DTVP. The MRI evaluation included diffusion tensor imaging and fractional anisotropy (FA, and colored orientation maps were calculated for each subject. Based on the results of the VEP evaluation, children were divided into two groups: A-abnormal results of VEP (n = 16 and B-normal VEP results (comparison group, n = 42. Results: FA values of inferior left and right occipital white matter (OWM were lower in the group of children with abnormal VEP compared to the comparison group (0.34 ± 0.06 vs. 0.38 ± 0.06; P = 0.047; 0.31 ± 0.04 vs. 0.36 ± 0.06; P = 0.007, respectively. Furthermore, there were correlations between the latency (r = −0.35; P = 0.01 and amplitude (r = 0.31; P = 0.02 and FA in OWM. Children with abnormal VEP had lower DTVP scores as compared with children with normal VEP results (88 ± 18 vs. 95 ± 16 points, P = 0.048. Finally, a multivariate logistic regression revealed that FA of the inferior OWM was the only independent risk factor for the abnormal VEP (P = 0.04. Conclusion: Visual perception, VEPs, and white matter microstructural abnormalities in very low birth weight children at the age of 3–4 are significantly correlated.

  19. Genome-wide discovered psychosis-risk gene ZNF804A impacts on white matter microstructure in health, schizophrenia and bipolar disorder

    Directory of Open Access Journals (Sweden)

    Emma-Jane Mallas

    2016-02-01

    Full Text Available Background. Schizophrenia (SZ and bipolar disorder (BD have both been associated with reduced microstructural white matter integrity using, as a proxy, fractional anisotropy (FA detected using diffusion tensor imaging (DTI. Genetic susceptibility for both illnesses has also been positively correlated in recent genome-wide association studies with allele A (adenine of single nucleotide polymorphism (SNP rs1344706 of the ZNF804A gene. However, little is known about how the genomic linkage disequilibrium region tagged by this SNP impacts on the brain to increase risk for psychosis. This study aimed to assess the impact of this risk variant on FA in patients with SZ, in those with BD and in healthy controls. Methods. 230 individuals were genotyped for the rs1344706 SNP and underwent DTI. We used tract-based spatial statistics (TBSS followed by an analysis of variance, with threshold-free cluster enhancement (TFCE, to assess underlying effects of genotype, diagnosis and their interaction, on FA. Results. As predicted, statistically significant reductions in FA across a widely distributed brain network (p < 0.05, TFCE-corrected were positively associated both with a diagnosis of SZ or BD and with the double (homozygous presence of the ZNF804A rs1344706 risk variant (A. The main effect of genotype was medium (d = 0.48 in a 44,054-voxel cluster and the effect in the SZ group alone was large (d = 1.01 in a 51,260-voxel cluster, with no significant effects in BD or controls, in isolation. No areas under a significant diagnosis by genotype interaction were found. Discussion. We provide the first evidence in a predominantly Caucasian clinical sample, of an association between ZNF804A rs1344706 A-homozygosity and reduced FA, both irrespective of diagnosis and particularly in SZ (in overlapping brain areas. This suggests that the previously observed involvement of this genomic region in psychosis susceptibility, and in impaired functional connectivity, may be

  20. White matter lesion progression

    DEFF Research Database (Denmark)

    Hofer, Edith; Cavalieri, Margherita; Bis, Joshua C

    2015-01-01

    10 cohorts. To assess the relative contribution of genetic factors to progression of WML, we compared in 7 cohorts risk models including demographics, vascular risk factors plus single-nucleotide polymorphisms that have been shown to be associated cross-sectionally with WML in the current......BACKGROUND AND PURPOSE: White matter lesion (WML) progression on magnetic resonance imaging is related to cognitive decline and stroke, but its determinants besides baseline WML burden are largely unknown. Here, we estimated heritability of WML progression, and sought common genetic variants...... associated with WML progression in elderly participants from the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium. METHODS: Heritability of WML progression was calculated in the Framingham Heart Study. The genome-wide association study included 7773 elderly participants from...

  1. Age at First Exposure to Football Is Associated with Altered Corpus Callosum White Matter Microstructure in Former Professional Football Players.

    Science.gov (United States)

    Stamm, Julie M; Koerte, Inga K; Muehlmann, Marc; Pasternak, Ofer; Bourlas, Alexandra P; Baugh, Christine M; Giwerc, Michelle Y; Zhu, Anni; Coleman, Michael J; Bouix, Sylvain; Fritts, Nathan G; Martin, Brett M; Chaisson, Christine; McClean, Michael D; Lin, Alexander P; Cantu, Robert C; Tripodis, Yorghos; Stern, Robert A; Shenton, Martha E

    2015-11-15

    Youth football players may incur hundreds of repetitive head impacts (RHI) in one season. Our recent research suggests that exposure to RHI during a critical neurodevelopmental period prior to age 12 may lead to greater later-life mood, behavioral, and cognitive impairments. Here, we examine the relationship between age of first exposure (AFE) to RHI through tackle football and later-life corpus callosum (CC) microstructure using magnetic resonance diffusion tensor imaging (DTI). Forty retired National Football League (NFL) players, ages 40-65, were matched by age and divided into two groups based on their AFE to tackle football: before age 12 or at age 12 or older. Participants underwent DTI on a 3 Tesla Siemens (TIM-Verio) magnet. The whole CC and five subregions were defined and seeded using deterministic tractography. Dependent measures were fractional anisotropy (FA), trace, axial diffusivity, and radial diffusivity. Results showed that former NFL players in the AFE <12 group had significantly lower FA in anterior three CC regions and higher radial diffusivity in the most anterior CC region than those in the AFE ≥12 group. This is the first study to find a relationship between AFE to RHI and later-life CC microstructure. These results suggest that incurring RHI during critical periods of CC development may disrupt neurodevelopmental processes, including myelination, resulting in altered CC microstructure.

  2. White matter microstructure in 22q11 deletion syndrome: a pilot diffusion tensor imaging and voxel-based morphometry study of children and adolescents.

    Science.gov (United States)

    Sundram, Frederick; Campbell, Linda E; Azuma, Rayna; Daly, Eileen; Bloemen, Oswald J N; Barker, Gareth J; Chitnis, Xavier; Jones, Derek K; van Amelsvoort, Therese; Murphy, Kieran C; Murphy, Declan G M

    2010-06-01

    Young people with 22q11 Deletion Syndrome (22q11DS) are at substantial risk for developing psychosis and have significant differences in white matter (WM) volume. However, there are few in vivo studies of both WM microstructural integrity (as measured using Diffusion Tensor (DT)-MRI) and WM volume in the same individual. We used DT-MRI and structural MRI (sMRI) with voxel based morphometry (VBM) to compare, respectively, the fractional anisotropy (FA) and WM volume of 11 children and adolescents with 22q11DS and 12 controls. Also, within 22q11DS we related differences in WM to severity of schizotypy, and polymorphism of the catechol-O-methyltransferase (COMT) gene. People with 22q11DS had significantly lower FA in inter-hemispheric and brainstem and frontal, parietal and temporal lobe regions after covarying for IQ. Significant WM volumetric increases were found in the internal capsule, anterior brainstem and frontal and occipital lobes. There was a significant negative correlation between increased schizotypy scores and reduced WM FA in the right posterior limb of internal capsule and the right body and left splenium of corpus callosum. Finally, the Val allele of COMT was associated with a significant reduction in both FA and volume of WM in the frontal lobes, cingulum and corpus callosum. Young people with 22q11DS have significant differences in both WM microstructure and volume. Also, there is preliminary evidence that within 22q11DS, some regional differences in FA are associated with allelic variation in COMT and may perhaps also be associated with schizotypy.

  3. Hemispheric Differences in White Matter Microstructure between Two Profiles of Children with High Intelligence Quotient vs. Controls: A Tract-Based Spatial Statistics Study

    Science.gov (United States)

    Nusbaum, Fanny; Hannoun, Salem; Kocevar, Gabriel; Stamile, Claudio; Fourneret, Pierre; Revol, Olivier; Sappey-Marinier, Dominique

    2017-01-01

    Objectives: The main goal of this study was to investigate and compare the neural substrate of two children's profiles of high intelligence quotient (HIQ). Methods: Two groups of HIQ children were included with either a homogeneous (Hom-HIQ: n = 20) or a heterogeneous IQ profile (Het-HIQ: n = 24) as defined by a significant difference between verbal comprehension index and perceptual reasoning index. Diffusion tensor imaging was used to assess white matter (WM) microstructure while tract-based spatial statistics (TBSS) analysis was performed to detect and localize WM regional differences in fractional anisotropy (FA), mean diffusivity, axial (AD), and radial diffusivities. Quantitative measurements were performed on 48 regions and 21 fiber-bundles of WM. Results: Hom-HIQ children presented higher FA than Het-HIQ children in widespread WM regions including central structures, and associative intra-hemispheric WM fasciculi. AD was also greater in numerous WM regions of Total-HIQ, Hom-HIQ, and Het-HIQ groups when compared to the Control group. Hom-HIQ and Het-HIQ groups also differed by their hemispheric lateralization in AD differences compared to Controls. Het-HIQ and Hom-HIQ groups showed a lateralization ratio (left/right) of 1.38 and 0.78, respectively. Conclusions: These findings suggest that both inter- and intra-hemispheric WM integrity are enhanced in HIQ children and that neural substrate differs between Hom-HIQ and Het-HIQ. The left hemispheric lateralization of Het-HIQ children is concordant with their higher verbal index while the relative right hemispheric lateralization of Hom-HIQ children is concordant with their global brain processing and adaptation capacities as evidenced by their homogeneous IQ. PMID:28420955

  4. Prediction of cognitive and motor development in preterm children using exhaustive feature selection and cross-validation of near-term white matter microstructure.

    Science.gov (United States)

    Schadl, Kornél; Vassar, Rachel; Cahill-Rowley, Katelyn; Yeom, Kristin W; Stevenson, David K; Rose, Jessica

    2018-01-01

    Advanced neuroimaging and computational methods offer opportunities for more accurate prognosis. We hypothesized that near-term regional white matter (WM) microstructure, assessed on diffusion tensor imaging (DTI), using exhaustive feature selection with cross-validation would predict neurodevelopment in preterm children. Near-term MRI and DTI obtained at 36.6 ± 1.8 weeks postmenstrual age in 66 very-low-birth-weight preterm neonates were assessed. 60/66 had follow-up neurodevelopmental evaluation with Bayley Scales of Infant-Toddler Development, 3rd-edition (BSID-III) at 18-22 months. Linear models with exhaustive feature selection and leave-one-out cross-validation computed based on DTI identified sets of three brain regions most predictive of cognitive and motor function; logistic regression models were computed to classify high-risk infants scoring one standard deviation below mean. Cognitive impairment was predicted (100% sensitivity, 100% specificity; AUC = 1) by near-term right middle-temporal gyrus MD, right cingulate-cingulum MD, left caudate MD. Motor impairment was predicted (90% sensitivity, 86% specificity; AUC = 0.912) by left precuneus FA, right superior occipital gyrus MD, right hippocampus FA. Cognitive score variance was explained (29.6%, cross-validated Rˆ2 = 0.296) by left posterior-limb-of-internal-capsule MD, Genu RD, right fusiform gyrus AD. Motor score variance was explained (31.7%, cross-validated Rˆ2 = 0.317) by left posterior-limb-of-internal-capsule MD, right parahippocampal gyrus AD, right middle-temporal gyrus AD. Search in large DTI feature space more accurately identified neonatal neuroimaging correlates of neurodevelopment.

  5. Gray matter and white matter abnormalities in online game addiction

    International Nuclear Information System (INIS)

    Weng, Chuan-Bo; Qian, Ruo-Bing; Fu, Xian-Ming; Lin, Bin; Han, Xiao-Peng; Niu, Chao-Shi; Wang, Ye-Han

    2013-01-01

    Online game addiction (OGA) has attracted greater attention as a serious public mental health issue. However, there are only a few brain magnetic resonance imaging studies on brain structure about OGA. In the current study, we used voxel-based morphometry (VBM) analysis and tract-based spatial statistics (TBSS) to investigate the microstructural changes in OGA and assessed the relationship between these morphology changes and the Young's Internet Addiction Scale (YIAS) scores within the OGA group. Compared with healthy subjects, OGA individuals showed significant gray matter atrophy in the right orbitofrontal cortex, bilateral insula, and right supplementary motor area. According to TBSS analysis, OGA subjects had significantly reduced FA in the right genu of corpus callosum, bilateral frontal lobe white matter, and right external capsule. Gray matter volumes (GMV) of the right orbitofrontal cortex, bilateral insula and FA values of the right external capsule were significantly positively correlated with the YIAS scores in the OGA subjects. Our findings suggested that microstructure abnormalities of gray and white matter were present in OGA subjects. This finding may provide more insights into the understanding of the underlying neural mechanisms of OGA

  6. Gray matter and white matter abnormalities in online game addiction

    Energy Technology Data Exchange (ETDEWEB)

    Weng, Chuan-Bo, E-mail: send007@163.com [Department of Neurosurgery, Anhui Provincial Hospital Affiliated to Anhui Medical University, 17 Lujiang Road, Hefei, Ahui Province 230001 (China); School of Neurosurgery, Anhui Medical University, 81 Meishang Road, Hefei, Anhui Province 230032 (China); Qian, Ruo-Bing, E-mail: rehomail@163.com [Department of Neurosurgery, Anhui Provincial Hospital Affiliated to Anhui Medical University, 17 Lujiang Road, Hefei, Ahui Province 230001 (China); Anhui Provincial Institute of Stereotactic Neurosurgery, 9 Lujiang Road, Hefei, Ahui Province 230001 (China); Fu, Xian-Ming, E-mail: 506537677@qq.com [Department of Neurosurgery, Anhui Provincial Hospital Affiliated to Anhui Medical University, 17 Lujiang Road, Hefei, Ahui Province 230001 (China); Anhui Provincial Institute of Stereotactic Neurosurgery, 9 Lujiang Road, Hefei, Ahui Province 230001 (China); Lin, Bin, E-mail: 274722758@qq.com [School of Neurosurgery, Anhui Medical University, 81 Meishang Road, Hefei, Anhui Province 230032 (China); Han, Xiao-Peng, E-mail: hanxiaopeng@163.com [Department of Psychology, Anhui Provincial Hospital Affiliated to Anhui Medical University, 17 Lujiang Road, Hefei, Ahui Province 230001 (China); Niu, Chao-Shi, E-mail: niuchaoshi@163.com [Department of Neurosurgery, Anhui Provincial Hospital Affiliated to Anhui Medical University, 17 Lujiang Road, Hefei, Ahui Province 230001 (China); Anhui Provincial Institute of Stereotactic Neurosurgery, 9 Lujiang Road, Hefei, Ahui Province 230001 (China); Wang, Ye-Han, E-mail: wangyehan@163.com [Department of Neurosurgery, Anhui Provincial Hospital Affiliated to Anhui Medical University, 17 Lujiang Road, Hefei, Ahui Province 230001 (China); Anhui Provincial Institute of Stereotactic Neurosurgery, 9 Lujiang Road, Hefei, Ahui Province 230001 (China)

    2013-08-15

    Online game addiction (OGA) has attracted greater attention as a serious public mental health issue. However, there are only a few brain magnetic resonance imaging studies on brain structure about OGA. In the current study, we used voxel-based morphometry (VBM) analysis and tract-based spatial statistics (TBSS) to investigate the microstructural changes in OGA and assessed the relationship between these morphology changes and the Young's Internet Addiction Scale (YIAS) scores within the OGA group. Compared with healthy subjects, OGA individuals showed significant gray matter atrophy in the right orbitofrontal cortex, bilateral insula, and right supplementary motor area. According to TBSS analysis, OGA subjects had significantly reduced FA in the right genu of corpus callosum, bilateral frontal lobe white matter, and right external capsule. Gray matter volumes (GMV) of the right orbitofrontal cortex, bilateral insula and FA values of the right external capsule were significantly positively correlated with the YIAS scores in the OGA subjects. Our findings suggested that microstructure abnormalities of gray and white matter were present in OGA subjects. This finding may provide more insights into the understanding of the underlying neural mechanisms of OGA.

  7. Gray matter and white matter abnormalities in online game addiction.

    Science.gov (United States)

    Weng, Chuan-Bo; Qian, Ruo-Bing; Fu, Xian-Ming; Lin, Bin; Han, Xiao-Peng; Niu, Chao-Shi; Wang, Ye-Han

    2013-08-01

    Online game addiction (OGA) has attracted greater attention as a serious public mental health issue. However, there are only a few brain magnetic resonance imaging studies on brain structure about OGA. In the current study, we used voxel-based morphometry (VBM) analysis and tract-based spatial statistics (TBSS) to investigate the microstructural changes in OGA and assessed the relationship between these morphology changes and the Young's Internet Addiction Scale (YIAS) scores within the OGA group. Compared with healthy subjects, OGA individuals showed significant gray matter atrophy in the right orbitofrontal cortex, bilateral insula, and right supplementary motor area. According to TBSS analysis, OGA subjects had significantly reduced FA in the right genu of corpus callosum, bilateral frontal lobe white matter, and right external capsule. Gray matter volumes (GMV) of the right orbitofrontal cortex, bilateral insula and FA values of the right external capsule were significantly positively correlated with the YIAS scores in the OGA subjects. Our findings suggested that microstructure abnormalities of gray and white matter were present in OGA subjects. This finding may provide more insights into the understanding of the underlying neural mechanisms of OGA. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  8. White matter integrity in kleptomania: A pilot study

    OpenAIRE

    Grant, Jon E.; Correia, Stephen; Brennan-Krohn, Thea

    2006-01-01

    This study's goal was to examine microstructural organization of frontal white matter in kleptomania. Ten females with DSM-IV kleptomania and 10 female controls underwent diffusion tensor imaging. Inferior frontal white matter was the a priori region of interest. Trace and fractional anisotropy (FA) were also calculated for frontal and posterior cortical regions in both subject groups. Kleptomania subjects had significantly higher mean frontal Trace, and significantly lower mean frontal FA th...

  9. Effects of Career Duration, Concussion History, and Playing Position on White Matter Microstructure and Functional Neural Recruitment in Former College and Professional Football Athletes.

    Science.gov (United States)

    Clark, Michael D; Varangis, Eleanna M L; Champagne, Allen A; Giovanello, Kelly S; Shi, Feng; Kerr, Zachary Y; Smith, J Keith; Guskiewicz, Kevin M

    2018-03-01

    Purpose To better understand the relationship between exposure to concussive and subconcussive head impacts, white matter integrity, and functional task-related neural activity in former U.S. football athletes. Materials and Methods Between 2011 and 2013, 61 cognitively unimpaired former collegiate and professional football players (age range, 52-65 years) provided informed consent to participate in this cross-sectional study. Participants were stratified across three crossed factors: career duration, concussion history, and primary playing position. Fractional anisotropy (FA) and blood oxygen level-dependent (BOLD) percent signal change (PSC) were measured with diffusion-weighted and task-related functional magnetic resonance imaging, respectively. Analyses of variance of FA and BOLD PSC were used to determine main or interaction effects of the three factors. Results A significant interaction between career duration and concussion history was observed; former college players with more than three concussions had lower FA in a broadly distributed area of white matter compared with those with zero to one concussion (t29 = 2.774; adjusted P = .037), and the opposite was observed for former professional players (t29 = 3.883; adjusted P = .001). A separate interaction between concussion history and position was observed: Nonspeed players with more than three concussions had lower FA in frontal white matter compared with those with zero to one concussion (t25 = 3.861; adjusted P = .002). Analysis of working memory-task BOLD PSC revealed a similar interaction between concussion history and position (all adjusted P history on white matter structure and neural recruitment. The differences in brain structure and function were observed in the absence of clinical impairment, which suggested that multimodal imaging may provide early markers of onset of traumatic neurodegenerative disease. © RSNA, 2017 Online supplemental material is available for this article.

  10. White matter integrity in kleptomania: A pilot study

    Science.gov (United States)

    Grant, Jon E.; Correia, Stephen; Brennan-Krohn, Thea

    2007-01-01

    This study's goal was to examine microstructural organization of frontal white matter in kleptomania. Ten females with DSM-IV kleptomania and 10 female controls underwent diffusion tensor imaging. Inferior frontal white matter was the a priori region of interest. Trace and fractional anisotropy (FA) were also calculated for frontal and posterior cortical regions in both subject groups. Kleptomania subjects had significantly higher mean frontal Trace, and significantly lower mean frontal FA than control subjects. Group differences remained significant when right and left frontal Trace and FA were analyzed. Groups did not differ significantly in posterior Trace or FA. Kleptomania may be associated with decreased white matter microstructural integrity in inferior frontal brain regions. PMID:16956753

  11. Neurocognitive Correlates of White Matter Quality in Adolescent Substance Users

    Science.gov (United States)

    Bava, Sunita; Jacobus, Joanna; Mahmood, Omar; Yang, Tony T.; Tapert, Susan F.

    2010-01-01

    Background: Progressive myelination during adolescence implicates an increased vulnerability to neurotoxic substances and enduring neurocognitive consequences. This study examined the cognitive manifestations of altered white matter microstructure in chronic marijuana and alcohol-using (MJ + ALC) adolescents. Methods: Thirty-six MJ + ALC…

  12. Socioeconomic status, white matter, and executive function in children.

    Science.gov (United States)

    Ursache, Alexandra; Noble, Kimberly G

    2016-10-01

    A growing body of evidence links socioeconomic status (SES) to children's brain structure. Few studies, however, have specifically investigated relations of SES to white matter structure. Further, although several studies have demonstrated that family SES is related to development of brain areas that support executive functions (EF), less is known about the role that white matter structure plays in the relation of SES to EF. One possibility is that white matter differences may partially explain SES disparities in EF (i.e., a mediating relationship). Alternatively, SES may differentially shape brain-behavior relations such that the relation of white matter structure to EF may differ as a function of SES (i.e., a moderating relationship). In a diverse sample of 1082 children and adolescents aged 3-21 years, we examined socioeconomic disparities in white matter macrostructure and microstructure. We further investigated relations between family SES, children's white matter volume and integrity in tracts supporting EF, and performance on EF tasks. Socioeconomic status was associated with fractional anisotropy (FA) and volume in multiple white matter tracts. Additionally, family income moderated the relation between white matter structure and cognitive flexibility. Specifically, across multiple tracts of interest, lower FA or lower volume was associated with reduced cognitive flexibility among children from lower income families. In contrast, children from higher income families showed preserved cognitive flexibility in the face of low white matter FA or volume. SES factors did not mediate or moderate links between white matter and either working memory or inhibitory control. This work adds to a growing body of literature suggesting that the socioeconomic contexts in which children develop not only shape cognitive functioning and its underlying neurobiology, but may also shape the relations between brain and behavior.

  13. Major Superficial White Matter Abnormalities in Huntington's Disease

    Science.gov (United States)

    Phillips, Owen R.; Joshi, Shantanu H.; Squitieri, Ferdinando; Sanchez-Castaneda, Cristina; Narr, Katherine; Shattuck, David W.; Caltagirone, Carlo; Sabatini, Umberto; Di Paola, Margherita

    2016-01-01

    Background: The late myelinating superficial white matter at the juncture of the cortical gray and white matter comprising the intracortical myelin and short-range association fibers has not received attention in Huntington's disease. It is an area of the brain that is late myelinating and is sensitive to both normal aging and neurodegenerative disease effects. Therefore, it may be sensitive to Huntington's disease processes. Methods: Structural MRI data from 25 Pre-symptomatic subjects, 24 Huntington's disease patients and 49 healthy controls was run through a cortical pattern-matching program. The surface corresponding to the white matter directly below the cortical gray matter was then extracted. Individual subject's Diffusion Tensor Imaging (DTI) data was aligned to their structural MRI data. Diffusivity values along the white matter surface were then sampled at each vertex point. DTI measures with high spatial resolution across the superficial white matter surface were then analyzed with the General Linear Model to test for the effects of disease. Results: There was an overall increase in the axial and radial diffusivity across much of the superficial white matter (p < 0.001) in Pre-symptomatic subjects compared to controls. In Huntington's disease patients increased diffusivity covered essentially the whole brain (p < 0.001). Changes are correlated with genotype (CAG repeat number) and disease burden (p < 0.001). Conclusions: This study showed broad abnormalities in superficial white matter even before symptoms are present in Huntington's disease. Since, the superficial white matter has a unique microstructure and function these abnormalities suggest it plays an important role in the disease. PMID:27242403

  14. Aging of cerebral white matter.

    Science.gov (United States)

    Liu, Huan; Yang, Yuanyuan; Xia, Yuguo; Zhu, Wen; Leak, Rehana K; Wei, Zhishuo; Wang, Jianyi; Hu, Xiaoming

    2017-03-01

    White matter (WM) occupies a large volume of the human cerebrum and is mainly composed of myelinated axons and myelin-producing glial cells. The myelinated axons within WM are the structural foundation for efficient neurotransmission between cortical and subcortical areas. Similar to neuron-enriched gray matter areas, WM undergoes a series of changes during the process of aging. WM malfunction can induce serious neurobehavioral and cognitive impairments. Thus, age-related changes in WM may contribute to the functional decline observed in the elderly. In addition, aged WM becomes more susceptible to neurological disorders, such as stroke, traumatic brain injury (TBI), and neurodegeneration. In this review, we summarize the structural and functional alterations of WM in natural aging and speculate on the underlying mechanisms. We also discuss how age-related WM changes influence the progression of various brain disorders, including ischemic and hemorrhagic stroke, TBI, Alzheimer's disease, and Parkinson's disease. Although the physiology of WM is still poorly understood relative to gray matter, WM is a rational therapeutic target for a number of neurological and psychiatric conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Alterations in the microstructure of white matter in children and adolescents with Tourette syndrome measured using tract-based spatial statistics and probabilistic tractography.

    Science.gov (United States)

    Sigurdsson, Hilmar P; Pépés, Sophia E; Jackson, Georgina M; Draper, Amelia; Morgan, Paul S; Jackson, Stephen R

    2018-04-12

    Tourette syndrome (TS) is a neurodevelopmental disorder characterised by repetitive and intermittent motor and vocal tics. TS is thought to reflect fronto-striatal dysfunction and the aetiology of the disorder has been linked to widespread alterations in the functional and structural integrity of the brain. The aim of this study was to assess white matter (WM) abnormalities in a large sample of young patients with TS in comparison to a sample of matched typically developing control individuals (CS) using diffusion MRI. The study included 35 patients with TS (3 females; mean age: 14.0 ± 3.3) and 35 CS (3 females; mean age: 13.9 ± 3.3). Diffusion MRI data was analysed using tract-based spatial statistics (TBSS) and probabilistic tractography. Patients with TS demonstrated both marked and widespread decreases in axial diffusivity (AD) together with altered WM connectivity. Moreover, we showed that tic severity and the frequency of premonitory urges (PU) were associated with increased connectivity between primary motor cortex (M1) and the caudate nuclei, and increased information transfer between M1 and the insula, respectively. This is to our knowledge the first study to employ both TBSS and probabilistic tractography in a sample of young patients with TS. Our results contribute to the limited existing literature demonstrating altered connectivity in TS and confirm previous results suggesting in particular, that altered insular function contributes to increased frequency of PU. Copyright © 2018. Published by Elsevier Ltd.

  16. Does the use of hormonal contraceptives cause microstructural changes in cerebral white matter? Preliminary results of a DTI and tractography study.

    Science.gov (United States)

    De Bondt, Timo; Van Hecke, Wim; Veraart, Jelle; Leemans, Alexander; Sijbers, Jan; Sunaert, Stefan; Jacquemyn, Yves; Parizel, Paul M

    2013-01-01

    To evaluate the effect of monophasic combined oral contraceptive pill (COCP) and menstrual cycle phase in healthy young women on white matter (WM) organization using diffusion tensor imaging (DTI). Thirty young women were included in the study; 15 women used COCP and 15 women had a natural cycle. All subjects underwent DTI magnetic resonance imaging during the follicular and luteal phase of their cycle, or in different COCP cycle phases. DTI parameters were obtained in different WM structures by performing diffusion tensor fibre tractography. Fractional anisotropy and mean diffusivity were calculated for different WM structures. Hormonal plasma concentrations were measured in peripheral venous blood samples and correlated with the DTI findings. We found a significant difference in mean diffusivity in the fornix between the COCP and the natural cycle group. Mean diffusivity values in the fornix were negatively correlated with luteinizing hormone and estradiol blood concentrations. An important part in the limbic system, the fornix, regulates emotional processes. Differences in diffusion parameters in the fornix may contribute to behavioural alternations related to COCP use. This finding also suggests that the use of oral contraceptives needs to be taken into account when designing DTI group studies.

  17. White matter hyperintensities and normal-appearing white matter integrity in the aging brain.

    Science.gov (United States)

    Maniega, Susana Muñoz; Valdés Hernández, Maria C; Clayden, Jonathan D; Royle, Natalie A; Murray, Catherine; Morris, Zoe; Aribisala, Benjamin S; Gow, Alan J; Starr, John M; Bastin, Mark E; Deary, Ian J; Wardlaw, Joanna M

    2015-02-01

    White matter hyperintensities (WMH) of presumed vascular origin are a common finding in brain magnetic resonance imaging of older individuals and contribute to cognitive and functional decline. It is unknown how WMH form, although white matter degeneration is characterized pathologically by demyelination, axonal loss, and rarefaction, often attributed to ischemia. Changes within normal-appearing white matter (NAWM) in subjects with WMH have also been reported but have not yet been fully characterized. Here, we describe the in vivo imaging signatures of both NAWM and WMH in a large group of community-dwelling older people of similar age using biomarkers derived from magnetic resonance imaging that collectively reflect white matter integrity, myelination, and brain water content. Fractional anisotropy (FA) and magnetization transfer ratio (MTR) were significantly lower, whereas mean diffusivity (MD) and longitudinal relaxation time (T1) were significantly higher, in WMH than NAWM (p curve, 0.982; 95% CI, 0.975-0.989). Furthermore, the level of deterioration of NAWM was strongly associated with the severity of WMH, with MD and T1 increasing and FA and MTR decreasing in NAWM with increasing WMH score, a relationship that was sustained regardless of distance from the WMH. These multimodal imaging data indicate that WMH have reduced structural integrity compared with surrounding NAWM, and MD provides the best discriminator between the 2 tissue classes even within the mild range of WMH severity, whereas FA, MTR, and T1 only start reflecting significant changes in tissue microstructure as WMH become more severe. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Altered Gray Matter Volume and White Matter Integrity in College Students with Mobile Phone Dependence

    OpenAIRE

    Wang, Yongming; Zou, Zhiling; Song, Hongwen; Xu, Xiaodan; Wang, Huijun; d?Oleire Uquillas, Federico; Huang, Xiting

    2016-01-01

    Mobile phone dependence (MPD) is a behavioral addiction that has become an increasing public mental health issue. While previous research has explored some of the factors that may predict MPD, the underlying neural mechanisms of MPD have not been investigated yet. The current study aimed to explore the microstructural variations associated with MPD as measured with functional Magnetic Resonance Imaging (fMRI). Gray matter volume (GMV) and white matter (WM) integrity [four indices: fractional ...

  19. Diffusion tensor imaging study of early white matter integrity in HIV-infected patients: A tract-based spatial statistics analysis

    Directory of Open Access Journals (Sweden)

    Ruili Li

    2015-12-01

    Conclusion: Multiple cerebral white matter fiber tracts are damaged in HIV-infected patients without cognitive impairment. Quantitative analysis of DTI using TBSS is valuable in evaluating changes of HIV-associated white matter microstructures.

  20. Development of White Matter Microstructure and Intrinsic Functional Connectivity Between the Amygdala and Ventromedial Prefrontal Cortex: Associations With Anxiety and Depression.

    Science.gov (United States)

    Jalbrzikowski, Maria; Larsen, Bart; Hallquist, Michael N; Foran, William; Calabro, Finnegan; Luna, Beatriz

    2017-10-01

    Connectivity between the amygdala and ventromedial prefrontal cortex (vmPFC) is compromised in multiple psychiatric disorders, many of which emerge during adolescence. To identify to what extent the deviations in amygdala-vmPFC maturation contribute to the onset of psychiatric disorders, it is essential to characterize amygdala-vmPFC connectivity changes during typical development. Using an accelerated cohort longitudinal design (1-3 time points, 10-25 years old, n = 246), we characterized developmental changes of the amygdala-vmPFC subregion functional and structural connectivity using resting-state functional magnetic resonance imaging and diffusion-weighted imaging. Functional connectivity between the centromedial amygdala and rostral anterior cingulate cortex (rACC), anterior vmPFC, and subgenual cingulate significantly decreased from late childhood to early adulthood in male and female subjects. Age-associated decreases were also observed between the basolateral amygdala and the rACC. Importantly, these findings were replicated in a separate cohort (10-22 years old, n = 327). Similarly, structural connectivity, as measured by quantitative anisotropy, significantly decreased with age in the same regions. Functional connectivity between the centromedial amygdala and the rACC was associated with structural connectivity in these same regions during early adulthood (22-25 years old). Finally, a novel time-varying coefficient analysis showed that increased centromedial amygdala-rACC functional connectivity was associated with greater anxiety and depression symptoms during early adulthood, while increased structural connectivity in centromedial amygdala-anterior vmPFC white matter was associated with greater anxiety/depression during late childhood. Specific developmental periods of functional and structural connectivity between the amygdala and the prefrontal systems may contribute to the emergence of anxiety and depressive symptoms and may play a critical role in

  1. Deficits in Docosahexaenoic Acid Accrual during Adolescence Reduce Rat Forebrain White Matter Microstructural Integrity: An in vivo Diffusion Tensor Imaging Study.

    Science.gov (United States)

    McNamara, Robert K; Schurdak, Jennifer D; Asch, Ruth H; Peters, Bart D; Lindquist, Diana M

    2018-01-01

    Neuropsychiatric disorders that frequently initially emerge during adolescence are associated with deficits in the omega-3 (n-3) fatty acid docosahexaenoic acid (DHA), elevated proinflammatory signaling, and regional reductions in white matter integrity (WMI). This study determined the effects of altering brain DHA accrual during adolescence on WMI in the rat brain by diffusion tensor imaging (DTI), and investigated the potential mediating role of proinflammatory signaling. During periadolescent development, male rats were fed a diet deficient in n-3 fatty acids (DEF, n = 20), a fish oil-fortified diet containing preformed DHA (FO, n = 20), or a control diet (CON, n = 20). In adulthood, DTI scans were performed and brain WMI was determined using voxelwise tract-based spatial statistics (TBSS). Postmortem fatty acid composition, peripheral (plasma IL-1β, IL-6, and C-reactive protein [CRP]) and central (IL-1β and CD11b mRNA) proinflammatory markers, and myelin basic protein (MBP) mRNA expression were determined. Compared with CON rats, forebrain DHA levels were lower in DEF rats and higher in FO rats. Compared with CON rats, DEF rats exhibited greater radial diffusivity (RD) and mean diffusivity in the right external capsule, and greater axial diffusivity in the corpus callosum genu and left external capsule. DEF rats also exhibited greater RD than FO rats in the right external capsule. Forebrain MBP expression did not differ between groups. Compared with CON rats, central (IL-1β and CD11b) and peripheral (IL-1β and IL-6) proinflammatory markers were not different in DEF rats, and DEF rats exhibited lower CRP levels. These findings demonstrate that deficits in adolescent DHA accrual negatively impact forebrain WMI, independently of elevated proinflammatory signaling. © 2017 S. Karger AG, Basel.

  2. Neurotransmitter signaling in white matter.

    Science.gov (United States)

    Butt, Arthur M; Fern, Robert F; Matute, Carlos

    2014-11-01

    White matter (WM) tracts are bundles of myelinated axons that provide for rapid communication throughout the CNS and integration in grey matter (GM). The main cells in myelinated tracts are oligodendrocytes and astrocytes, with small populations of microglia and oligodendrocyte precursor cells. The prominence of neurotransmitter signaling in WM, which largely exclude neuronal cell bodies, indicates it must have physiological functions other than neuron-to-neuron communication. A surprising aspect is the diversity of neurotransmitter signaling in WM, with evidence for glutamatergic, purinergic (ATP and adenosine), GABAergic, glycinergic, adrenergic, cholinergic, dopaminergic and serotonergic signaling, acting via a wide range of ionotropic and metabotropic receptors. Both axons and glia are potential sources of neurotransmitters and may express the respective receptors. The physiological functions of neurotransmitter signaling in WM are subject to debate, but glutamate and ATP-mediated signaling have been shown to evoke Ca(2+) signals in glia and modulate axonal conduction. Experimental findings support a model of neurotransmitters being released from axons during action potential propagation acting on glial receptors to regulate the homeostatic functions of astrocytes and myelination by oligodendrocytes. Astrocytes also release neurotransmitters, which act on axonal receptors to strengthen action potential propagation, maintaining signaling along potentially long axon tracts. The co-existence of multiple neurotransmitters in WM tracts suggests they may have diverse functions that are important for information processing. Furthermore, the neurotransmitter signaling phenomena described in WM most likely apply to myelinated axons of the cerebral cortex and GM areas, where they are doubtless important for higher cognitive function. © 2014 Wiley Periodicals, Inc.

  3. Organising white matter in a brain without corpus callosum fibres.

    Science.gov (United States)

    Bénézit, Audrey; Hertz-Pannier, Lucie; Dehaene-Lambertz, Ghislaine; Monzalvo, Karla; Germanaud, David; Duclap, Delphine; Guevara, Pamela; Mangin, Jean-François; Poupon, Cyril; Moutard, Marie-Laure; Dubois, Jessica

    2015-02-01

    Isolated corpus callosum dysgenesis (CCD) is a congenital malformation which occurs during early development of the brain. In this study, we aimed to identify and describe its consequences beyond the lack of callosal fibres, on the morphology, microstructure and asymmetries of the main white matter bundles with diffusion imaging and fibre tractography. Seven children aged between 9 and 13 years old and seven age- and gender-matched control children were studied. First, we focused on bundles within the mesial region of the cerebral hemispheres: the corpus callosum, Probst bundles and cingulum which were selected using a conventional region-based approach. We demonstrated that the Probst bundles have a wider connectivity than the previously described rostrocaudal direction, and a microstructure rather distinct from the cingulum but relatively close to callosal remnant fibres. A sigmoid bundle was found in two partial ageneses. Second, the corticospinal tract, thalamic radiations and association bundles were extracted automatically via an atlas of adult white matter bundles to overcome bias resulting from a priori knowledge of the bundles' anatomical morphology and trajectory. Despite the lack of callosal fibres and the colpocephaly observed in CCD, all major white matter bundles were identified with a relatively normal morphology, and preserved microstructure (i.e. fractional anisotropy, mean diffusivity) and asymmetries. Consequently the bundles' organisation seems well conserved in brains with CCD. These results await further investigations with functional imaging before apprehending the cognition variability in children with isolated dysgenesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. White matter damage is related to ataxia severity in SCA3.

    Science.gov (United States)

    Kang, J-S; Klein, J C; Baudrexel, S; Deichmann, R; Nolte, D; Hilker, R

    2014-02-01

    Spinocerebellar ataxia type 3 (SCA3) is the most frequent inherited cerebellar ataxia in Europe, the US and Japan, leading to disability and death through motor complications. Although the affected protein ataxin-3 is found ubiquitously in the brain, grey matter atrophy is predominant in the cerebellum and the brainstem. White matter pathology is generally less severe and thought to occur in the brainstem, spinal cord, and cerebellar white matter. Here, we investigated both grey and white matter pathology in a group of 12 SCA3 patients and matched controls. We used voxel-based morphometry for analysis of tissue loss, and tract-based spatial statistics (TBSS) on diffusion magnetic resonance imaging to investigate microstructural pathology. We analysed correlations between microstructural properties of the brain and ataxia severity, as measured by the Scale for the Assessment and Rating of Ataxia (SARA) score. SCA3 patients exhibited significant loss of both grey and white matter in the cerebellar hemispheres, brainstem including pons and in lateral thalamus. On between-group analysis, TBSS detected widespread microstructural white matter pathology in the cerebellum, brainstem, and bilaterally in thalamus and the cerebral hemispheres. Furthermore, fractional anisotropy in a white matter network comprising frontal, thalamic, brainstem and left cerebellar white matter strongly and negatively correlated with SARA ataxia scores. Tractography identified the thalamic white matter thus implicated as belonging to ventrolateral thalamus. Disruption of white matter integrity in patients suffering from SCA3 is more widespread than previously thought. Moreover, our data provide evidence that microstructural white matter changes in SCA3 are strongly related to the clinical severity of ataxia symptoms.

  5. White matter abnormalities in tuberous sclerosis complex

    Energy Technology Data Exchange (ETDEWEB)

    Griffiths, P.D. [Sheffield Univ. (United Kingdom). Academic Dept. of Radiology; Bolton, P. [Cambridge Univ. (United Kingdom). Section of Developmental Psychiatry; Verity, C. [Addenbrooke`s NHS Trust, Cambridge (United Kingdom). Dept. of Paediatric Radiology

    1998-09-01

    The aim of this study was to investigate and describe the range of white matter abnormalities in children with tuberous sclerosis complex by means of MR imaging. Material and Methods: A retrospective cross-sectional study was performed on the basis of MR imaging findings in 20 cases of tuberous sclerosis complex in children aged 17 years or younger. Results: White matter abnormalities were present in 19/20 (95%) cases of tuberous sclerosis complex. These were most frequently (19/20 cases) found in relation to cortical tubers in the supratentorial compartment. White matter abnormalities related to tubers were found in the cerebellum in 3/20 (15%) cases. White matter abnormalities described as radial migration lines were found in relation to 5 tubers in 3 (15%) children. In 4/20 (20%) cases, white matter abnormalities were found that were not related to cortical tubers. These areas had the appearance of white matter cysts in 3 cases and infarction in the fourth. In the latter case there was a definable event in the clinical history, supporting the diagnosis of stroke. Conclusion: A range of white matter abnormalities were found by MR imaging in tuberous sclerosis complex, the commonest being gliosis and hypomyelination related to cortical tubers. Radial migration lines were seen infrequently in relation to cortical tubers and these are thought to represent heterotopic glia and neurons along the expected path of cortical migration. (orig.)

  6. White matter disease of the brain

    International Nuclear Information System (INIS)

    Melville, G.E.; Fernandez, R.E.; Kishore, P.R.S.; Lee, S.H.

    1987-01-01

    The white matter disorders that are discussed in this chapter are subdivided into those disorders within which there is breakdown of normal myelin, termed myelinoclastic, and those diseases involving either formation or maintenance of abnormal myeline, termed dysmyelinating. CT is a well-established technique for studying white matter disease. Magnetic resonance imaging (MRI) is a new noninvasive technique which has shown greater sensitivity to white matter abnormalities. However, because of the rarity of may white matter diseases coupled with limited availability of MR facilities, the MRI experience in evaluating these patients is not extensive yet. Some patients may not be suitable for MRI because of the longer period of patient immobility that is required to avoid motion artifacts

  7. On Describing Human White Matter Anatomy: The White Matter Query Language

    OpenAIRE

    Wassermann, Demian; Makris, Nikos; Rathi, Yogesh; Shenton, Martha; Kikinis, Ron; Kubicki, Marek; Westin, Carl-Fredrik

    2013-01-01

    The main contribution of this work is the careful syntactical definition of major white matter tracts in the human brain based on a neuroanatomist’s expert knowledge. We present a technique to formally describe white matter tracts and to automatically extract them from diffusion MRI data. The framework is based on a novel query language with a near-to-English textual syntax. This query language allows us to construct a dictionary of anatomical definitions describing white matter tracts. The d...

  8. White matter pathways in persistent developmental stuttering: Lessons from tractography.

    Science.gov (United States)

    Kronfeld-Duenias, Vered; Civier, Oren; Amir, Ofer; Ezrati-Vinacour, Ruth; Ben-Shachar, Michal

    2018-03-01

    Fluent speech production relies on the coordinated processing of multiple brain regions. This highlights the role of neural pathways that connect distinct brain regions in producing fluent speech. Here, we aim to investigate the role of the white matter pathways in persistent developmental stuttering (PDS), where speech fluency is disrupted. We use diffusion weighted imaging and tractography to compare the white matter properties between adults who do and do not stutter. We compare the diffusion properties along 18 major cerebral white matter pathways. We complement the analysis with an overview of the methodology and a roadmap of the pathways implicated in PDS according to the existing literature. We report differences in the microstructural properties of the anterior callosum, the right inferior longitudinal fasciculus and the right cingulum in people who stutter compared with fluent controls. Persistent developmental stuttering is consistently associated with differences in bilateral distributed networks. We review evidence showing that PDS involves differences in bilateral dorsal fronto-temporal and fronto-parietal pathways, in callosal pathways, in several motor pathways and in basal ganglia connections. This entails an important role for long range white matter pathways in this disorder. Using a wide-lens analysis, we demonstrate differences in additional, right hemispheric pathways, which go beyond the replicable findings in the literature. This suggests that the affected circuits may extend beyond the known language and motor pathways. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Differential vulnerability of gray matter and white matter to intrauterine growth restriction in preterm infants at 12 months corrected age.

    Science.gov (United States)

    Padilla, Nelly; Junqué, Carme; Figueras, Francesc; Sanz-Cortes, Magdalena; Bargalló, Núria; Arranz, Angela; Donaire, Antonio; Figueras, Josep; Gratacos, Eduard

    2014-01-30

    Intrauterine growth restriction (IUGR) is associated with a high risk of abnormal neurodevelopment. Underlying neuroanatomical substrates are partially documented. We hypothesized that at 12 months preterm infants would evidence specific white-matter microstructure alterations and gray-matter differences induced by severe IUGR. Twenty preterm infants with IUGR (26-34 weeks of gestation) were compared with 20 term-born infants and 20 appropriate for gestational age preterm infants of similar gestational age. Preterm groups showed no evidence of brain abnormalities. At 12 months, infants were scanned sleeping naturally. Gray-matter volumes were studied with voxel-based morphometry. White-matter microstructure was examined using tract-based spatial statistics. The relationship between diffusivity indices in white matter, gray matter volumes, and perinatal data was also investigated. Gray-matter decrements attributable to IUGR comprised amygdala, basal ganglia, thalamus and insula bilaterally, left occipital and parietal lobes, and right perirolandic area. Gray-matter volumes positively correlated with birth weight exclusively. Preterm infants had reduced FA in the corpus callosum, and increased FA in the anterior corona radiata. Additionally, IUGR infants had increased FA in the forceps minor, internal and external capsules, uncinate and fronto-occipital white matter tracts. Increased axial diffusivity was observed in several white matter tracts. Fractional anisotropy positively correlated with birth weight and gestational age at birth. These data suggest that IUGR differentially affects gray and white matter development preferentially affecting gray matter. At 12 months IUGR is associated with a specific set of structural gray-matter decrements. White matter follows an unusual developmental pattern, and is apparently affected by IUGR and prematurity combined. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Strength of Temporal White Matter Pathways Predicts Semantic Learning.

    Science.gov (United States)

    Ripollés, Pablo; Biel, Davina; Peñaloza, Claudia; Kaufmann, Jörn; Marco-Pallarés, Josep; Noesselt, Toemme; Rodríguez-Fornells, Antoni

    2017-11-15

    Learning the associations between words and meanings is a fundamental human ability. Although the language network is cortically well defined, the role of the white matter pathways supporting novel word-to-meaning mappings remains unclear. Here, by using contextual and cross-situational word learning, we tested whether learning the meaning of a new word is related to the integrity of the language-related white matter pathways in 40 adults (18 women). The arcuate, uncinate, inferior-fronto-occipital and inferior-longitudinal fasciculi were virtually dissected using manual and automatic deterministic fiber tracking. Critically, the automatic method allowed assessing the white matter microstructure along the tract. Results demonstrate that the microstructural properties of the left inferior-longitudinal fasciculus predict contextual learning, whereas the left uncinate was associated with cross-situational learning. In addition, we identified regions of special importance within these pathways: the posterior middle temporal gyrus, thought to serve as a lexical interface and specifically related to contextual learning; the anterior temporal lobe, known to be an amodal hub for semantic processing and related to cross-situational learning; and the white matter near the hippocampus, a structure fundamental for the initial stages of new-word learning and, remarkably, related to both types of word learning. No significant associations were found for the inferior-fronto-occipital fasciculus or the arcuate. While previous results suggest that learning new phonological word forms is mediated by the arcuate fasciculus, these findings show that the temporal pathways are the crucial neural substrate supporting one of the most striking human abilities: our capacity to identify correct associations between words and meanings under referential indeterminacy. SIGNIFICANCE STATEMENT The language-processing network is cortically (i.e., gray matter) well defined. However, the role of the

  11. Deviant white matter structure in adults with attention-deficit/hyperactivity disorder points to aberrant myelination and affects neuropsychological performance

    NARCIS (Netherlands)

    Onnink, A.M.H.; Zwiers, M.P.; Hoogman, M.; Mostert, J.C.; Dammers, J.; Kan, C.C.; Arias Vasquez, A.; Schene, A.H.; Buitelaar, J.K.; Franke, B.

    2015-01-01

    Attention-deficit/hyperactivity disorder (ADHD) in childhood is characterized by gray and white matter abnormalities in several brain areas. Considerably less is known about white matter microstructure in adults with ADHD and its relation with clinical symptoms and cognitive performance. In 107

  12. Leukoencephalopathy With Vanishing White Matter: A Review

    NARCIS (Netherlands)

    Bugiani, M.; Boor, I.; Powers, J.M.; Scheper, G.C.; van der Knaap, M.S.

    2010-01-01

    Vanishing white matter (VWM) is one of the most prevalent inherited childhood leukoencephalopathies, but this may affect people ofall ages, including neonates and adults. It is a progressive disorder clinically dominated by cerebellar ataxia and in which minor stress conditions, such as fever or

  13. Leukoencephalopathy with vanishing white matter: a review

    NARCIS (Netherlands)

    Bugiani, Marianna; Boor, Ilja; Powers, James M.; Scheper, Gert C.; van der Knaap, Marjo S.

    2010-01-01

    Vanishing white matter (VWM) is one of the most prevalent inherited childhood leukoencephalopathies, but this may affect people of all ages, including neonates and adults. It is a progressive disorder clinically dominated by cerebellar ataxia and in which minor stress conditions, such as fever or

  14. The effects of puberty on white matter development in boys.

    Science.gov (United States)

    Menzies, Lara; Goddings, Anne-Lise; Whitaker, Kirstie J; Blakemore, Sarah-Jayne; Viner, Russell M

    2015-02-01

    Neuroimaging studies demonstrate considerable changes in white matter volume and microstructure during adolescence. Most studies have focused on age-related effects, whilst puberty-related changes are not well understood. Using diffusion tensor imaging and tract-based spatial statistics, we investigated the effects of pubertal status on white matter mean diffusivity (MD) and fractional anisotropy (FA) in 61 males aged 12.7-16.0 years. Participants were grouped into early-mid puberty (≤Tanner Stage 3 in pubic hair and gonadal development; n=22) and late-post puberty (≥Tanner Stage 4 in pubic hair or gonadal development; n=39). Salivary levels of pubertal hormones (testosterone, DHEA and oestradiol) were also measured. Pubertal stage was significantly related to MD in diverse white matter regions. No relationship was observed between pubertal status and FA. Regression modelling of MD in the significant regions demonstrated that an interaction model incorporating puberty, age and puberty×age best explained our findings. In addition, testosterone was correlated with MD in these pubertally significant regions. No relationship was observed between oestradiol or DHEA and MD. In conclusion, pubertal status was significantly related to MD, but not FA, and this relationship cannot be explained by changes in chronological age alone. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Never forget a name: white matter connectivity predicts person memory

    Science.gov (United States)

    Metoki, Athanasia; Alm, Kylie H.; Wang, Yin; Ngo, Chi T.; Olson, Ingrid R.

    2018-01-01

    Through learning and practice, we can acquire numerous skills, ranging from the simple (whistling) to the complex (memorizing operettas in a foreign language). It has been proposed that complex learning requires a network of brain regions that interact with one another via white matter pathways. One candidate white matter pathway, the uncinate fasciculus (UF), has exhibited mixed results for this hypothesis: some studies have shown UF involvement across a range of memory tasks, while other studies report null results. Here, we tested the hypothesis that the UF supports associative memory processes and that this tract can be parcellated into subtracts that support specific types of memory. Healthy young adults performed behavioral tasks (two face-name learning tasks, one word pair memory task) and underwent a diffusion-weighted imaging scan. Our results revealed that variation in UF microstructure was significantly associated with individual differences in performance on both face-name tasks, as well as the word association memory task. A UF sub-tract, functionally defined by its connectivity between face-selective regions in the anterior temporal lobe and orbitofrontal cortex, selectively predicted face-name learning. In contrast, connectivity between the fusiform face patch and both anterior face patches had no predictive validity. These findings suggest that there is a robust and replicable relationship between the UF and associative learning and memory. Moreover, this large white matter pathway can be subdivided to reveal discrete functional profiles. PMID:28646241

  16. White matter structure changes as adults learn a second language.

    Science.gov (United States)

    Schlegel, Alexander A; Rudelson, Justin J; Tse, Peter U

    2012-08-01

    Traditional models hold that the plastic reorganization of brain structures occurs mainly during childhood and adolescence, leaving adults with limited means to learn new knowledge and skills. Research within the last decade has begun to overturn this belief, documenting changes in the brain's gray and white matter as healthy adults learn simple motor and cognitive skills [Lövdén, M., Bodammer, N. C., Kühn, S., Kaufmann, J., Schütze, H., Tempelmann, C., et al. Experience-dependent plasticity of white-matter microstructure extends into old age. Neuropsychologia, 48, 3878-3883, 2010; Taubert, M., Draganski, B., Anwander, A., Müller, K., Horstmann, A., Villringer, A., et al. Dynamic properties of human brain structure: Learning-related changes in cortical areas and associated fiber connections. The Journal of Neuroscience, 30, 11670-11677, 2010; Scholz, J., Klein, M. C., Behrens, T. E. J., & Johansen-Berg, H. Training induces changes in white-matter architecture. Nature Neuroscience, 12, 1370-1371, 2009; Draganski, B., Gaser, C., Busch, V., Schuirer, G., Bogdahn, U., & May, A. Changes in grey matter induced by training. Nature, 427, 311-312, 2004]. Although the significance of these changes is not fully understood, they reveal a brain that remains plastic well beyond early developmental periods. Here we investigate the role of adult structural plasticity in the complex, long-term learning process of foreign language acquisition. We collected monthly diffusion tensor imaging scans of 11 English speakers who took a 9-month intensive course in written and spoken Modern Standard Chinese as well as from 16 control participants who did not study a language. We show that white matter reorganizes progressively across multiple sites as adults study a new language. Language learners exhibited progressive changes in white matter tracts associated with traditional left hemisphere language areas and their right hemisphere analogs. Surprisingly, the most significant changes

  17. White Matter Integrity Deficit Associated with Betel Quid Dependence

    Directory of Open Access Journals (Sweden)

    Fulai Yuan

    2017-10-01

    Full Text Available Betel quid (BQ is a commonly consumed psychoactive substance, which has been regarded as a human carcinogen. Long-term BQ chewing may cause Diagnostic and Statistical Manual of Mental Disorders-IV dependence symptoms, which can lead to decreased cognitive functions, such as attention and inhibition control. Although betel quid dependence (BQD individuals have been reported with altered brain structure and function, there is little evidence showing white matter microstructure alternation in BQD individuals. The present study aimed to investigate altered white matter microstructure in BQD individuals using diffusion tensor imaging. Tract-based spatial statistics was used to analyze the data. Compared with healthy controls, BQD individuals exhibited higher mean diffusivity (MD in anterior thalamic radiation (ATR. Further analysis revealed that the ATR in BQD individuals showed less fractional anisotropy (FA than that in healthy controls. Correlation analysis showed that both the increase of MD and reduction of FA in BQD individuals were associated with severity of BQ dependence. These results suggested that BQD would disrupt the balance between prefrontal cortex and subcortical areas, causing declined inhibition control.

  18. White Matter Integrity Deficit Associated with Betel Quid Dependence.

    Science.gov (United States)

    Yuan, Fulai; Zhu, Xueling; Kong, Lingyu; Shen, Huaizhen; Liao, Weihua; Jiang, Canhua

    2017-01-01

    Betel quid (BQ) is a commonly consumed psychoactive substance, which has been regarded as a human carcinogen. Long-term BQ chewing may cause Diagnostic and Statistical Manual of Mental Disorders-IV dependence symptoms, which can lead to decreased cognitive functions, such as attention and inhibition control. Although betel quid dependence (BQD) individuals have been reported with altered brain structure and function, there is little evidence showing white matter microstructure alternation in BQD individuals. The present study aimed to investigate altered white matter microstructure in BQD individuals using diffusion tensor imaging. Tract-based spatial statistics was used to analyze the data. Compared with healthy controls, BQD individuals exhibited higher mean diffusivity (MD) in anterior thalamic radiation (ATR). Further analysis revealed that the ATR in BQD individuals showed less fractional anisotropy (FA) than that in healthy controls. Correlation analysis showed that both the increase of MD and reduction of FA in BQD individuals were associated with severity of BQ dependence. These results suggested that BQD would disrupt the balance between prefrontal cortex and subcortical areas, causing declined inhibition control.

  19. Heterogeneity in age-related white matter changes

    NARCIS (Netherlands)

    Schmidt, R.; Schmidt, H.; Haybaeck, J.; Loitfelder, M.; Weis, S.; Cavalieri, M.; Seiler, S.; Enzinger, C.; Ropele, S.; Erkinjuntti, T.; Pantoni, L.; Scheltens, P.; Fazekas, F.; Jellinger, K.

    2011-01-01

    White matter changes occur endemically in routine magnetic resonance imaging (MRI) scans of elderly persons. MRI appearance and histopathological correlates of white matter changes are heterogeneous. Smooth periventricular hyperintensities, including caps around the ventricular horns,

  20. White matter alterations in neurodegenerative and vascular dementia

    International Nuclear Information System (INIS)

    Supprian, T.; Kessler, H.; Falkai, P.; Retz, W.; Roesler, M.; Grunwald, I.; Reith, W.

    2003-01-01

    Due to a significant overlap of the two syndromes, differentiation of degenerative dementia of the Alzheimer-type from vascular dementia may be difficult even when imaging studies are available. White matter changes occur in many patients suffering from Alzheimer's disease. Little is known about the impact of white matter changes on the course and clinical presentation of Alzheimer's disease. High sensitivity of MRI in the detection of white matter alterations may account for over-diagnosing vascular dementia. The clinical significance of white matter alterations in dementia is still a matter of debate. The article reviews current concepts about the role of white matter alterations in dementia. (orig.) [de

  1. Anisotropic diffusion within human white matter

    International Nuclear Information System (INIS)

    Chenevert, T.L.; Brunberg, J.A.; Pipe, J.G.

    1990-01-01

    This paper reports on measurements performed to assess the impact of fiber orientation on the apparent diffusion coefficient of human white matter in vivo. Orthogonal section selection pulses and strong motion sensitization gradient pulses were used for localized diffusion measurement along an anteroposteriorly oriented 1 x 1 cm tissue column in the left cerebral hemisphere. This region was selected since white matter fiber orientations are reasonably well defined. Independent acquisitions with motion sensitivity along anteroposterior and right-left directions allowed study of diffusion anisotropy. Motion artifacts were minimized by magnitude summation after one-dimensional Fourier transform of frequency-encoded echoes; consequently, cardiac gating was not required. Five normal volunteers were studied on a 1.5-T clinical MR system

  2. White Matter Glial Pathology in Autism

    Science.gov (United States)

    2015-11-01

    AWARD NUMBER: W81XWH-12-1-0302 TITLE: White Matter Glial Pathology in Autism PRINCIPAL INVESTIGATOR: Gregory A. Ordway, Ph.D. CONTRACTING...Pathology in Autism 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-12-1-0302 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Gregory A. Ordway, Ph.D...Approved for Public Release; Distribution Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Methods used to directly study the autism brain include brain

  3. Integrated analysis of gray and white matter alterations in attention-deficit/hyperactivity disorder

    NARCIS (Netherlands)

    Francx, W.C.; Llera, A.; Mennes, M.; Zwiers, M.P.; Faraone, S.V; Oosterlaan, J.; Heslenfeld, D.; Hoekstra, P.J.; Hartman, C.A.; Franke, B.; Buitelaar, J.K.; Beckmann, C.F.

    2016-01-01

    BACKGROUND: Magnetic resonance imaging (MRI) is able to provide detailed insights into the structural organization of the brain, e.g., by means of mapping brain anatomy and white matter microstructure. Understanding interrelations between MRI modalities, rather than mapping modalities in isolation,

  4. Integrated analysis of gray and white matter alterations in attention-deficit/hyperactivity disorder

    NARCIS (Netherlands)

    Francx, Winke; Llera, Alberto; Mennes, Maarten; Zwiers, Marcel P.; Faraone, Stephen V.; Oosterlaan, Jaap; Heslenfeld, Dirk; Hoekstra, Pieter J.; Hartman, Catharina A.; Franke, Barbara; Buitelaar, Jan K.; Beckmann, Christian F.

    2016-01-01

    Background: Magnetic resonance imaging (MRI) is able to provide detailed insights into the structural organization of the brain, e.g., by means of mapping brain anatomy and white matter microstructure. Understanding interrelations between MRI modalities, rather than mapping modalities in isolation,

  5. White Matter Pathways and Social Cognition.

    Science.gov (United States)

    Wang, Yin; Metoki, Athanasia; Alm, Kylie H; Olson, Ingrid R

    2018-04-20

    There is a growing consensus that social cognition and behavior emerge from interactions across distributed regions of the "social brain". Researchers have traditionally focused their attention on functional response properties of these gray matter networks and neglected the vital role of white matter connections in establishing such networks and their functions. In this article, we conduct a comprehensive review of prior research on structural connectivity in social neuroscience and highlight the importance of this literature in clarifying brain mechanisms of social cognition. We pay particular attention to three key social processes: face processing, embodied cognition, and theory of mind, and their respective underlying neural networks. To fully identify and characterize the anatomical architecture of these networks, we further implement probabilistic tractography on a large sample of diffusion-weighted imaging data. The combination of an in-depth literature review and the empirical investigation gives us an unprecedented, well-defined landscape of white matter pathways underlying major social brain networks. Finally, we discuss current problems in the field, outline suggestions for best practice in diffusion-imaging data collection and analysis, and offer new directions for future research. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. White matter connectivity and Internet gaming disorder

    Science.gov (United States)

    Jeong, Bum Seok; Han, Doug Hyun; Kim, Sun Mi; Lee, Sang Won; Renshaw, Perry F.

    2017-01-01

    Internet use and on-line game play stimulate corticostriatal-limbic circuitry in both healthy subjects and subjects with Internet gaming disorder (IGD). We hypothesized that increased fractional anisotropy (FA) with decreased radial diffusivity (RD) would be observed in IGD subjects, compared with healthy control subjects, and that these white matter indices would be associated with clinical variables including duration of illness and executive function. We screened 181 male patients in order to recruit a large number (n = 58) of IGD subjects without psychiatric co-morbidity as well as 26 male healthy comparison subjects. Multiple diffusion-weighted images were acquired using a 3.0 Tesla magnetic resonance imaging scanner. Tract-based spatial statistics was applied to compare group differences in diffusion tensor imaging (DTI) metrics between IGD and healthy comparison subjects. IGD subjects had increased FA values within forceps minor, right anterior thalamic radiation, right corticospinal tract, right inferior longitudinal fasciculus, right cingulum to hippocampus and right inferior fronto-occipital fasciculus (IFOF) as well as parallel decreases in RD value within forceps minor, right anterior thalamic radiation and IFOF relative to healthy control subjects. In addition, the duration of illness in IGD subjects was positively correlated with the FA values (integrity of white matter fibers) and negatively correlated with RD scores (diffusivity of axonal density) of whole brain white matter. In IGD subjects without psychiatric co-morbidity, our DTI results suggest that increased myelination (increased FA and decreased RD values) in right-sided frontal fiber tracts may be the result of extended game play. PMID:25899390

  7. Age-Related White Matter Changes

    Directory of Open Access Journals (Sweden)

    Yun Yun Xiong

    2011-01-01

    Full Text Available Age-related white matter changes (WMC are considered manifestation of arteriolosclerotic small vessel disease and are related to age and vascular risk factors. Most recent studies have shown that WMC are associated with a host of poor outcomes, including cognitive impairment, dementia, urinary incontinence, gait disturbances, depression, and increased risk of stroke and death. Although the clinical relevance of WMC has been extensively studied, to date, only very few clinical trials have evaluated potential symptomatic or preventive treatments for WMC. In this paper, we reviewed the current understanding in the pathophysiology, epidemiology, clinical importance, chemical biomarkers, and treatments of age-related WMC.

  8. White Matter Lesion Progression in LADIS

    DEFF Research Database (Denmark)

    Schmidt, Reinhold; Berghold, Andrea; Jokinen, Hanna

    2012-01-01

    BACKGROUND AND PURPOSE: White matter lesion (WML) progression has been advocated as a surrogate marker in intervention trials on cerebral small vessel disease. We assessed the rate of visually rated WML progression, studied correlations between lesion progression and cognition, and estimated sample...... sizes for clinical trials with pure WML progression vs combined WML progression-cognitive outcomes. METHODS: Those 394 participants of the Leukoaraiosis and Disability Study (LADIS) study with magnetic resonance imaging scanning at baseline and 3-year follow-up were analyzed. WML progression rating...

  9. A longitudinal study of computerized cognitive training in stroke patients - effects on cognitive function and white matter.

    Science.gov (United States)

    Nyberg, Claudia Kim; Nordvik, Jan Egil; Becker, Frank; Rohani, Darius A; Sederevicius, Donatas; Fjell, Anders M; Walhovd, Kristine B

    2018-05-01

    Background Computerized cognitive training is suggested to enhance attention and working memory functioning following stroke, but effects on brain and behavior are not sufficiently studied and longitudinal studies assessing brain and behavior relationships are scarce. Objective The study objectives were to investigate relations between neuropsychological performance post-stroke and white matter microstructure measures derived from diffusion tensor imaging (DTI), including changes after 6 weeks of working memory training. Methods In this experimental training study, 26 stroke patients underwent DTI and neuropsychological tests at 3 time points - before and after a passive phase of 6 weeks, and again after 6 weeks of working memory training (Cogmed QM). Fractional anisotropy (FA) was extracted from stroke-free brain areas to assess the white matter microstructure. Twenty-two participants completed the majority of training (≥18/25 sessions) and were entered into longitudinal analyses. Results Significant correlations between FA and baseline cognitive functions were observed (r = 0.58, p = 0.004), however, no evidence was found of generally improved cognitive functions following training or of changes in white matter microstructure. Conclusions While white matter microstructure related to baseline cognitive function in stroke patients, the study revealed no effect on cognitive functions or microstructural changes in white matter in relation to computerized working memory training.

  10. DTI and VBM reveal white matter changes without associated gray matter changes in patients with idiopathic restless legs syndrome

    Science.gov (United States)

    Belke, Marcus; Heverhagen, Johannes T; Keil, Boris; Rosenow, Felix; Oertel, Wolfgang H; Stiasny-Kolster, Karin; Knake, Susanne; Menzler, Katja

    2015-01-01

    Background and Purpose We evaluated cerebral white and gray matter changes in patients with iRLS in order to shed light on the pathophysiology of this disease. Methods Twelve patients with iRLS were compared to 12 age- and sex-matched controls using whole-head diffusion tensor imaging (DTI) and voxel-based morphometry (VBM) techniques. Evaluation of the DTI scans included the voxelwise analysis of the fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD). Results Diffusion tensor imaging revealed areas of altered FA in subcortical white matter bilaterally, mainly in temporal regions as well as in the right internal capsule, the pons, and the right cerebellum. These changes overlapped with changes in RD. Voxel-based morphometry did not reveal any gray matter alterations. Conclusions We showed altered diffusion properties in several white matter regions in patients with iRLS. White matter changes could mainly be attributed to changes in RD, a parameter thought to reflect altered myelination. Areas with altered white matter microstructure included areas in the internal capsule which include the corticospinal tract to the lower limbs, thereby supporting studies that suggest changes in sensorimotor pathways associated with RLS. PMID:26442748

  11. Evidence for Functional Networks within the Human Brain's White Matter.

    Science.gov (United States)

    Peer, Michael; Nitzan, Mor; Bick, Atira S; Levin, Netta; Arzy, Shahar

    2017-07-05

    Investigation of the functional macro-scale organization of the human cortex is fundamental in modern neuroscience. Although numerous studies have identified networks of interacting functional modules in the gray-matter, limited research was directed to the functional organization of the white-matter. Recent studies have demonstrated that the white-matter exhibits blood oxygen level-dependent signal fluctuations similar to those of the gray-matter. Here we used these signal fluctuations to investigate whether the white-matter is organized as functional networks by applying a clustering analysis on resting-state functional MRI (RSfMRI) data from white-matter voxels, in 176 subjects (of both sexes). This analysis indicated the existence of 12 symmetrical white-matter functional networks, corresponding to combinations of white-matter tracts identified by diffusion tensor imaging. Six of the networks included interhemispheric commissural bridges traversing the corpus callosum. Signals in white-matter networks correlated with signals from functional gray-matter networks, providing missing knowledge on how these distributed networks communicate across large distances. These findings were replicated in an independent subject group and were corroborated by seed-based analysis in small groups and individual subjects. The identified white-matter functional atlases and analysis codes are available at http://mind.huji.ac.il/white-matter.aspx Our results demonstrate that the white-matter manifests an intrinsic functional organization as interacting networks of functional modules, similarly to the gray-matter, which can be investigated using RSfMRI. The discovery of functional networks within the white-matter may open new avenues of research in cognitive neuroscience and clinical neuropsychiatry. SIGNIFICANCE STATEMENT In recent years, functional MRI (fMRI) has revolutionized all fields of neuroscience, enabling identifications of functional modules and networks in the human

  12. [Research on brain white matter network in cerebral palsy infant].

    Science.gov (United States)

    Li, Jun; Yang, Cheng; Wang, Yuanjun; Nie, Shengdong

    2017-10-01

    Present study used diffusion tensor image and tractography to construct brain white matter networks of 15 cerebral palsy infants and 30 healthy infants that matched for age and gender. After white matter network analysis, we found that both cerebral palsy and healthy infants had a small-world topology in white matter network, but cerebral palsy infants exhibited abnormal topological organization: increased shortest path length but decreased normalize clustering coefficient, global efficiency and local efficiency. Furthermore, we also found that white matter network hub regions were located in the left cuneus, precuneus, and left posterior cingulate gyrus. However, some abnormal nodes existed in the frontal, temporal, occipital and parietal lobes of cerebral palsy infants. These results indicated that the white matter networks for cerebral palsy infants were disrupted, which was consistent with previous studies about the abnormal brain white matter areas. This work could help us further study the pathogenesis of cerebral palsy infants.

  13. White matter involvement in sporadic Creutzfeldt-Jakob disease.

    Science.gov (United States)

    Caverzasi, Eduardo; Mandelli, Maria Luisa; DeArmond, Stephen J; Hess, Christopher P; Vitali, Paolo; Papinutto, Nico; Oehler, Abby; Miller, Bruce L; Lobach, Irina V; Bastianello, Stefano; Geschwind, Michael D; Henry, Roland G

    2014-12-01

    Sporadic Creutzfeldt-Jakob disease is considered primarily a disease of grey matter, although the extent of white matter involvement has not been well described. We used diffusion tensor imaging to study the white matter in sporadic Creutzfeldt-Jakob disease compared to healthy control subjects and to correlated magnetic resonance imaging findings with histopathology. Twenty-six patients with sporadic Creutzfeldt-Jakob disease and nine age- and gender-matched healthy control subjects underwent volumetric T1-weighted and diffusion tensor imaging. Six patients had post-mortem brain analysis available for assessment of neuropathological findings associated with prion disease. Parcellation of the subcortical white matter was performed on 3D T1-weighted volumes using Freesurfer. Diffusion tensor imaging maps were calculated and transformed to the 3D-T1 space; the average value for each diffusion metric was calculated in the total white matter and in regional volumes of interest. Tract-based spatial statistics analysis was also performed to investigate the deeper white matter tracts. There was a significant reduction of mean (P=0.002), axial (P=0.0003) and radial (P=0.0134) diffusivities in the total white matter in sporadic Creutzfeldt-Jakob disease. Mean diffusivity was significantly lower in most white matter volumes of interest (PCreutzfeldt-Jakob disease. Mean diffusivity reduction reflected concomitant decrease of both axial and radial diffusivity, without appreciable changes in white matter anisotropy. Tract-based spatial statistics analysis showed significant reductions of mean diffusivity within the white matter of patients with sporadic Creutzfeldt-Jakob disease, mainly in the left hemisphere, with a strong trend (P=0.06) towards reduced mean diffusivity in most of the white matter bilaterally. In contrast, by visual assessment there was no white matter abnormality either on T2-weighted or diffusion-weighted images. Widespread reduction in white matter mean

  14. White matter volume changes in people who develop psychosis.

    Science.gov (United States)

    Walterfang, Mark; McGuire, Philip K; Yung, Alison R; Phillips, Lisa J; Velakoulis, Dennis; Wood, Stephen J; Suckling, John; Bullmore, Edward T; Brewer, Warrick; Soulsby, Bridget; Desmond, Patricia; McGorry, Patrick D; Pantelis, Christos

    2008-09-01

    Grey matter changes have been described in individuals who are pre- and peri-psychotic, but it is unclear if these changes are accompanied by changes in white matter structures. To determine whether changes in white matter occur prior to and with the transition to psychosis in individuals who are pre-psychotic who had previously demonstrated grey matter reductions in frontotemporal regions. We used magnetic resonance imaging (MRI) to examine regional white matter volume in 75 people with prodromal symptoms. A subset of the original group (n=21) were rescanned at 12-18 months to determine white matter volume changes. Participants were retrospectively categorised according to whether they had or had not developed psychosis at follow-up. Comparison of the baseline MRI data from these two subgroups revealed that individuals who later developed psychosis had larger volumes of white matter in the frontal lobe, particularly in the left hemisphere. Longitudinal comparison of data in individuals who developed psychosis revealed a reduction in white matter volume in the region of the left fronto-occipital fasciculus. Participants who had not developed psychosis showed no reductions in white matter volume but increases in a region subjacent to the right inferior parietal lobule. The reduction in volume of white matter near the left fronto-occipital fasciculus may reflect a change in this tract in association with the onset of frank psychosis.

  15. Frontoparietal white matter integrity predicts haptic performance in chronic stroke

    Directory of Open Access Journals (Sweden)

    Alexandra L. Borstad

    2016-01-01

    Full Text Available Frontoparietal white matter supports information transfer between brain areas involved in complex haptic tasks such as somatosensory discrimination. The purpose of this study was to gain an understanding of the relationship between microstructural integrity of frontoparietal network white matter and haptic performance in persons with chronic stroke and to compare frontoparietal network integrity in participants with stroke and age matched control participants. Nineteen individuals with stroke and 16 controls participated. Haptic performance was quantified using the Hand Active Sensation Test (HASTe, an 18-item match-to-sample test of weight and texture discrimination. Three tesla MRI was used to obtain diffusion-weighted and high-resolution anatomical images of the whole brain. Probabilistic tractography was used to define 10 frontoparietal tracts total; Four intrahemispheric tracts measured bilaterally 1 thalamus to primary somatosensory cortex (T–S1, 2 thalamus to primary motor cortex (T–M1, 3 primary to secondary somatosensory cortex (S1 to SII and 4 primary somatosensory cortex to middle frontal gyrus (S1 to MFG and, 2 interhemispheric tracts; S1–S1 and precuneus interhemispheric. A control tract outside the network, the cuneus interhemispheric tract, was also examined. The diffusion metrics fractional anisotropy (FA, mean diffusivity (MD, axial (AD and radial diffusivity (RD were quantified for each tract. Diminished FA and elevated MD values are associated with poorer white matter integrity in chronic stroke. Nine of 10 tracts quantified in the frontoparietal network had diminished structural integrity poststroke compared to the controls. The precuneus interhemispheric tract was not significantly different between groups. Principle component analysis across all frontoparietal white matter tract MD values indicated a single factor explained 47% and 57% of the variance in tract mean diffusivity in stroke and control groups respectively

  16. Frontoparietal white matter integrity predicts haptic performance in chronic stroke.

    Science.gov (United States)

    Borstad, Alexandra L; Choi, Seongjin; Schmalbrock, Petra; Nichols-Larsen, Deborah S

    2016-01-01

    Frontoparietal white matter supports information transfer between brain areas involved in complex haptic tasks such as somatosensory discrimination. The purpose of this study was to gain an understanding of the relationship between microstructural integrity of frontoparietal network white matter and haptic performance in persons with chronic stroke and to compare frontoparietal network integrity in participants with stroke and age matched control participants. Nineteen individuals with stroke and 16 controls participated. Haptic performance was quantified using the Hand Active Sensation Test (HASTe), an 18-item match-to-sample test of weight and texture discrimination. Three tesla MRI was used to obtain diffusion-weighted and high-resolution anatomical images of the whole brain. Probabilistic tractography was used to define 10 frontoparietal tracts total; Four intrahemispheric tracts measured bilaterally 1) thalamus to primary somatosensory cortex (T-S1), 2) thalamus to primary motor cortex (T-M1), 3) primary to secondary somatosensory cortex (S1 to SII) and 4) primary somatosensory cortex to middle frontal gyrus (S1 to MFG) and, 2 interhemispheric tracts; S1-S1 and precuneus interhemispheric. A control tract outside the network, the cuneus interhemispheric tract, was also examined. The diffusion metrics fractional anisotropy (FA), mean diffusivity (MD), axial (AD) and radial diffusivity (RD) were quantified for each tract. Diminished FA and elevated MD values are associated with poorer white matter integrity in chronic stroke. Nine of 10 tracts quantified in the frontoparietal network had diminished structural integrity poststroke compared to the controls. The precuneus interhemispheric tract was not significantly different between groups. Principle component analysis across all frontoparietal white matter tract MD values indicated a single factor explained 47% and 57% of the variance in tract mean diffusivity in stroke and control groups respectively. Age

  17. White Matter Changes in Bipolar Disorder, Alzheimer Disease, and Mild Cognitive Impairment: New Insights from DTI

    Directory of Open Access Journals (Sweden)

    Aikaterini Xekardaki

    2011-01-01

    Full Text Available Neuropathological and neuroimaging studies have reported significant changes in white matter in psychiatric and neurodegenerative diseases. Diffusion tensor imaging (DTI, a recently developed technique, enables the detection of microstructural changes in white matter. It is a noninvasive in vivo technique that assesses water molecules' diffusion in brain tissues. The most commonly used parameters are axial and radial diffusivity reflecting diffusion along and perpendicular to the axons, as well as mean diffusivity and fractional anisotropy representing global diffusion. Although the combination of these parameters provides valuable information about the integrity of brain circuits, their physiological meaning still remains controversial. After reviewing the basic principles of DTI, we report on recent contributions that used this technique to explore subtle structural changes in white matter occurring in elderly patients with bipolar disorder and Alzheimer disease.

  18. White matter hyperintensities and changes in white matter integrity in patients with Alzheimer's disease

    International Nuclear Information System (INIS)

    Wang, Liya; Mao, Hui; Goldstein, Felicia C.; Levey, Allan I.; Lah, James J.; Meltzer, Carolyn C.; Holder, Chad A.

    2011-01-01

    White matter hyperintensities (WMHs) are a risk factor for Alzheimer's disease (AD). This study investigated the relationship between WMHs and white matter changes in AD using diffusion tensor imaging (DTI) and the sensitivity of each DTI index in distinguishing AD with WMHs. Forty-four subjects with WMHs were included. Subjects were classified into three groups based on the Scheltens rating scale: 15 AD patients with mild WMHs, 12 AD patients with severe WMHs, and 17 controls with mild WMHs. Fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (D R ), and axial diffusivity (D A ) were analyzed using the region of interest and tract-based spatial statistics methods. Sensitivity and specificity of DTI indices in distinguishing AD groups from the controls were evaluated. AD patients with mild WMHs exhibited differences from control subjects in most DTI indices in the medial temporal and frontal areas; however, differences in DTI indices from AD patients with mild WMHs and AD patients with severe WMHs were found in the parietal and occipital areas. FA and D R were more sensitive measurements than MD and D A in differentiating AD patients from controls, while MD was a more sensitive measurement in distinguishing AD patients with severe WMHs from those with mild WMHs. WMHs may contribute to the white matter changes in AD brains, specifically in temporal and frontal areas. Changes in parietal and occipital lobes may be related to the severity of WMHs. D R may serve as an imaging marker of myelin deficits associated with AD. (orig.)

  19. Automated measurement of local white matter lesion volume

    DEFF Research Database (Denmark)

    van der Lijn, Fedde; Verhaaren, Benjamin F. J.; Ikram, M. Arfan

    2012-01-01

    in a periventricular region close to the ventricles and a subcortical zone further away. In this work we present a novel automated method for local white matter lesion volume quantification in magnetic resonance images. The method segments and measures the white matter lesion volume in 43 regions defined...

  20. Astrocytes are central in the pathomechanisms of vanishing white matter

    NARCIS (Netherlands)

    Dooves, Stephanie; Bugiani, Marianna; Postma, Nienke L.; Polder, Emiel; Land, Niels; Horan, Stephen T.; van Deijk, Anne-Lieke F.; van de Kreeke, Aleid; Jacobs, Gerbren; Vuong, Caroline; Klooster, Jan; Kamermans, Maarten; Wortel, Joke; Loos, Maarten; Wisse, Lisanne E.; Scheper, Gert C.; Abbink, Truus E. M.; Heine, Vivi M.; van der Knaap, Marjo S.

    2016-01-01

    Vanishing white matter (VWM) is a fatal leukodystrophy that is caused by mutations in genes encoding subunits of eukaryotic translation initiation factor 2B (eIF2B). Disease onset and severity are codetermined by genotype. White matter astrocytes and oligodendrocytes are almost exclusively affected;

  1. Contrast between white and grey matter: MRI appearance with ageing

    International Nuclear Information System (INIS)

    Magnaldi, S.; Ukmar, M.; Vasciaveo, A.; Longo, R.; Pozzi-Mucelli, R.S.

    1993-01-01

    MRI contrast between white and grey matter appears to be higher in young normal subjects than in older patients. The aim of the present study was to investigate the possible relationships between these changes in contrast and ageing. It consisted of two parts. In the first part we retrospectively evaluated 140 MRI brain examinations of healthy subjects, 20 per decade (age range 20-90 years), in whom the contrast was subjectively scored. In the second part we prospectively measured the actual T1, spin density (SD) and T2 values of white and grey matter in another 22 healthy subjects (age range 20-80 years). In the first group of subjects a progressive decrease in white/grey matter contrast was observed with ageing. In the second group of subjects the T1, SD and T2 values of white matter were always shorter than those of grey matter. There is a close relation among T1, SD and T2 values of white and grey matter with ageing. We suggest that there is a progressive loss of white/grey matter contrast with ageing. Such a phenomenon is possibly due to an increased water content in the white matter and the progressive neuronal loss in the grey matter that occurs with age. (orig.)

  2. Diffusion tensor imaging tensor shape analysis for assessment of regional white matter differences.

    Science.gov (United States)

    Middleton, Dana M; Li, Jonathan Y; Lee, Hui J; Chen, Steven; Dickson, Patricia I; Ellinwood, N Matthew; White, Leonard E; Provenzale, James M

    2017-08-01

    Purpose The purpose of this study was to investigate a novel tensor shape plot analysis technique of diffusion tensor imaging data as a means to assess microstructural differences in brain tissue. We hypothesized that this technique could distinguish white matter regions with different microstructural compositions. Methods Three normal canines were euthanized at seven weeks old. Their brains were imaged using identical diffusion tensor imaging protocols on a 7T small-animal magnetic resonance imaging system. We examined two white matter regions, the internal capsule and the centrum semiovale, each subdivided into an anterior and posterior region. We placed 100 regions of interest in each of the four brain regions. Eigenvalues for each region of interest triangulated onto tensor shape plots as the weighted average of three shape metrics at the plot's vertices: CS, CL, and CP. Results The distribution of data on the plots for the internal capsule differed markedly from the centrum semiovale data, thus confirming our hypothesis. Furthermore, data for the internal capsule were distributed in a relatively tight cluster, possibly reflecting the compact and parallel nature of its fibers, while data for the centrum semiovale were more widely distributed, consistent with the less compact and often crossing pattern of its fibers. This indicates that the tensor shape plot technique can depict data in similar regions as being alike. Conclusion Tensor shape plots successfully depicted differences in tissue microstructure and reflected the microstructure of individual brain regions. This proof of principle study suggests that if our findings are reproduced in larger samples, including abnormal white matter states, the technique may be useful in assessment of white matter diseases.

  3. Cortex Parcellation Associated Whole White Matter Parcellation in Individual Subjects

    Directory of Open Access Journals (Sweden)

    Patrick Schiffler

    2017-07-01

    Full Text Available The investigation of specific white matter areas is a growing field in neurological research and is typically achieved through the use of atlases. However, the definition of anatomically based regions remains challenging for the white matter and thus hinders region-specific analysis in individual subjects. In this article, we focus on creating a whole white matter parcellation method for individual subjects where these areas can be associated to cortex regions. This is done by combining cortex parcellation and fiber tracking data. By tracking fibers out of each cortex region and labeling the fibers according to their origin, we populate a candidate image. We then derive the white matter parcellation by classifying each white matter voxel according to the distribution of labels in the corresponding voxel from the candidate image. The parcellation of the white matter with the presented method is highly reliable and is not as dependent on registration as with white matter atlases. This method allows for the parcellation of the whole white matter into individual cortex region associated areas and, therefore, associates white matter alterations to cortex regions. In addition, we compare the results from the presented method to existing atlases. The areas generated by the presented method are not as sharply defined as the areas in most existing atlases; however, they are computed directly in the DWI space of the subject and, therefore, do not suffer from distortion caused by registration. The presented approach might be a promising tool for clinical and basic research to investigate modalities or system specific micro structural alterations of white matter areas in a quantitative manner.

  4. Subcortical White Matter Changes with Normal Aging Detected by Multi-Shot High Resolution Diffusion Tensor Imaging.

    Directory of Open Access Journals (Sweden)

    Sheng Xie

    Full Text Available Subcortical white matter builds neural connections between cortical and subcortical regions and constitutes the basis of neural networks. It plays a very important role in normal brain function. Various studies have shown that white matter deteriorates with aging. However, due to the limited spatial resolution provided by traditional diffusion imaging techniques, microstructural information from subcortical white matter with normal aging has not been comprehensively assessed. This study aims to investigate the deterioration effect with aging in the subcortical white matter and provide a baseline standard for pathological disorder diagnosis. We apply our newly developed multi-shot high resolution diffusion tensor imaging, using self-feeding multiplexed sensitivity-encoding, to measure subcortical white matter changes in regions of interest of healthy persons with a wide age range. Results show significant fractional anisotropy decline and radial diffusivity increasing with age, especially in the anterior part of the brain. We also find that subcortical white matter has more prominent changes than white matter close to the central brain. The observed changes in the subcortical white matter may be indicative of a mild demyelination and a loss of myelinated axons, which may contribute to normal age-related functional decline.

  5. White matter cysts in patients with tuberous sclerosis

    International Nuclear Information System (INIS)

    Marti-Bonmati, L.; Dosda, R.; Menor, F.; Arana, E.; Poyatos, C.

    1999-01-01

    The presence of cysts in the white matter of the central nervous system of patients with tuberous sclerosis (TS) is an uncommon finding that has been reported only recently in neuroimaging studies. This article assesses the prevalence of these lesions in a large series of patients studied by magnetic resonance imaging (MRI) and their relationship to other epidemiological and imaging findings. MRI studies were performed in 46 patients (23 males and 23 females) with a mean age of 12.7 years, and the results were examined retrospectively in the search for cortical tubers, subependymal nodules and white matter nodules, lines and cysts. Nine patients (19.6%) presented cysts in white matter. Seven had only one cyst and the remaining two patients each had two. Multiple regression analysis relating the presence of the cysts with other neuroimaging findings in these patients revealed a statistically significant relationship only with white matter nodules (odds ratio: 7.5; p=0.006). White matter cysts are small, supratentorial lesions of deep location. There is a statistically relationship between the presence of these cysts and that of nodular lesions in the white matter. This finding supports the theory that the cyst originate from white matter nodules. (Author) 17 refs

  6. Abnormal white matter properties in adolescent girls with anorexia nervosa

    Directory of Open Access Journals (Sweden)

    Katherine E. Travis

    2015-01-01

    Full Text Available Anorexia nervosa (AN is a serious eating disorder that typically emerges during adolescence and occurs most frequently in females. To date, very few studies have investigated the possible impact of AN on white matter tissue properties during adolescence, when white matter is still developing. The present study evaluated white matter tissue properties in adolescent girls with AN using diffusion MRI with tractography and T1 relaxometry to measure R1 (1/T1, an index of myelin content. Fifteen adolescent girls with AN (mean age = 16.6 years ± 1.4 were compared to fifteen age-matched girls with normal weight and eating behaviors (mean age = 17.1 years ± 1.3. We identified and segmented 9 bilateral cerebral tracts (18 and 8 callosal fiber tracts in each participant's brain (26 total. Tract profiles were generated by computing measures for fractional anisotropy (FA and R1 along the trajectory of each tract. Compared to controls, FA in the AN group was significantly decreased in 4 of 26 white matter tracts and significantly increased in 2 of 26 white matter tracts. R1 was significantly decreased in the AN group compared to controls in 11 of 26 white matter tracts. Reduced FA in combination with reduced R1 suggests that the observed white matter differences in AN are likely due to reductions in myelin content. For the majority of tracts, group differences in FA and R1 did not occur within the same tract. The present findings have important implications for understanding the neurobiological factors underlying white matter changes associated with AN and invite further investigations examining associations between white matter properties and specific physiological, cognitive, social, or emotional functions affected in AN.

  7. Abnormal white matter properties in adolescent girls with anorexia nervosa

    Science.gov (United States)

    Travis, Katherine E.; Golden, Neville H.; Feldman, Heidi M.; Solomon, Murray; Nguyen, Jenny; Mezer, Aviv; Yeatman, Jason D.; Dougherty, Robert F.

    2015-01-01

    Anorexia nervosa (AN) is a serious eating disorder that typically emerges during adolescence and occurs most frequently in females. To date, very few studies have investigated the possible impact of AN on white matter tissue properties during adolescence, when white matter is still developing. The present study evaluated white matter tissue properties in adolescent girls with AN using diffusion MRI with tractography and T1 relaxometry to measure R1 (1/T1), an index of myelin content. Fifteen adolescent girls with AN (mean age = 16.6 years ± 1.4) were compared to fifteen age-matched girls with normal weight and eating behaviors (mean age = 17.1 years ± 1.3). We identified and segmented 9 bilateral cerebral tracts (18) and 8 callosal fiber tracts in each participant's brain (26 total). Tract profiles were generated by computing measures for fractional anisotropy (FA) and R1 along the trajectory of each tract. Compared to controls, FA in the AN group was significantly decreased in 4 of 26 white matter tracts and significantly increased in 2 of 26 white matter tracts. R1 was significantly decreased in the AN group compared to controls in 11 of 26 white matter tracts. Reduced FA in combination with reduced R1 suggests that the observed white matter differences in AN are likely due to reductions in myelin content. For the majority of tracts, group differences in FA and R1 did not occur within the same tract. The present findings have important implications for understanding the neurobiological factors underlying white matter changes associated with AN and invite further investigations examining associations between white matter properties and specific physiological, cognitive, social, or emotional functions affected in AN. PMID:26740918

  8. Medial frontal white and gray matter contributions to general intelligence.

    Directory of Open Access Journals (Sweden)

    Toshiyuki Ohtani

    Full Text Available The medial orbitofrontal cortex (mOFC and rostral anterior cingulate cortex (rACC are part of a wider neural network that plays an important role in general intelligence and executive function. We used structural brain imaging to quantify magnetic resonance gray matter volume and diffusion tensor white matter integrity of the mOFC-rACC network in 26 healthy participants who also completed neuropsychological tests of intellectual abilities and executive function. Stochastic tractography, the most effective Diffusion Tensor Imaging method for examining white matter connections between adjacent gray matter regions, was employed to assess the integrity of mOFC-rACC pathways. Fractional anisotropy (FA, which reflects the integrity of white matter connections, was calculated. Results indicated that higher intelligence correlated with greater gray matter volumes for both mOFC and rACC, as well as with increased FA for left posterior mOFC-rACC connectivity. Hierarchical regression analyses revealed that DTI-derived FA of left posterior mOFC-rACC uniquely accounted for 29%-34% of the variance in IQ, in comparison to 11%-16% uniquely explained by gray matter volume of the left rACC. Together, left rACC gray matter volume and white matter connectivity between left posterior mOFC and rACC accounted for up to 50% of the variance in general intelligence. This study is to our knowledge the first to examine white matter connectivity between OFC and ACC, two gray matter regions of interests that are very close in physical proximity, and underscores the important independent contributions of variations in rACC gray matter volume and mOFC-rACC white matter connectivity to individual differences in general intelligence.

  9. MR imaging of white-matter diseases in children

    International Nuclear Information System (INIS)

    Sato, Y.; Yuh, W.T.C.; Mathews, K.; Wiese, J.; Kao, S.; Schreiber, A.; Farner, R.; Smith, W.

    1987-01-01

    MR imaging has become a valuable tool in the investigation of central nervous system abnormalities in children. This exhibit displays the MR imaging patterns in 30 children with diseases involving the white matter. Clinical, CT, and pathologic findings will be presented for comparison. The white matter disease entities studies include acquired white matter diseases, metabolic diseases, and phycomatoses. Specific examples include acute dissemination encephalomyelitis, anoxic encephalopathy, disseminated necrotizing leukoencephalopathy, demyelinating adrenoleukodystrophy, Krabbe disease, metachromatic leukodystrophy, Tay-Sachs disease, Gaucher disease, neurofibromatosis, and Sturge-Weber syndrome

  10. Altered gray matter volume and white matter integrity in college students with mobile phone dependence

    Directory of Open Access Journals (Sweden)

    Yongming eWang

    2016-05-01

    Full Text Available Mobile phone dependence (MPD is a behavioral addiction that has become an increasing public mental health issue. While previous research has explored some of the factors that may predict MPD, the underlying neural mechanisms of MPD have not been investigated yet. The current study aimed to explore the microstructural variations associated with MPD as measured with functional Magnetic Resonance Imaging (fMRI. Gray matter volume (GMV and white matter (WM integrity (four indexes: fractional anisotropy, FA; mean diffusivity, MD; axial diffusivity, AD; and radial diffusivity, RD were calculated via voxel-based morphometry (VBM and tract-based spatial statistics (TBSS analysis, respectively. Sixty-eight college students (42 female were enrolled and separated into two groups (MPD group, N=34; control group, N=34 based on Mobile Phone Addiction Index (MPAI scale score. Trait impulsivity was also measured using the Barrett Impulsivity Scale (BIS-11. In light of underlying trait impulsivity, results revealed decreased GMV in the MPD group relative to controls in regions such as the right superior frontal gyrus (sFG, right inferior frontal gyrus (iFG, and bilateral thalamus (Thal. In the MPD group, GMV in the above mentioned regions was negatively correlated with scores on the MPAI. Results also showed significantly less FA and AD measures of white matter integrity in the MPD group relative to controls in bilateral hippocampal cingulum bundle fibers (CgH. Additionally, in the MPD group, FA of the CgH was also negatively correlated with scores on the MPAI. These findings provide the first morphological evidence of altered brain structure with phone-overuse, and may help to better understand the neural mechanisms of MPD in relation with other behavioral and substance addiction disorders.

  11. Menopausal Hot Flashes and White Matter Hyperintensities

    Science.gov (United States)

    Thurston, Rebecca C.; Aizenstein, Howard J.; Derby, Carol A.; Sejdić, Ervin; Maki, Pauline M.

    2015-01-01

    Objective Hot flashes are the classic menopausal symptom. Emerging data links hot flashes to cardiovascular disease (CVD) risk, yet how hot flashes are related to brain health is poorly understood. We examined the relationship between hot flashes - measured via physiologic monitor and self-report - and white matter hyperintensities (WMH) among midlife women. Methods Twenty midlife women ages 40-60 without clinical CVD, with their uterus and both ovaries, and not taking hormone therapy were recruited. Women underwent 24 hours of ambulatory physiologic and diary hot flash monitoring to quantify hot flashes; magnetic resonance imaging to assess WMH burden; 72 hours of actigraphy and questionnaires to quantify sleep; and a blood draw, questionnaires, and physical measures to quantify demographics and CVD risk factors. Test of a priori hypotheses regarding relations between physiologically-monitored and self-reported wake and sleep hot flashes and WMH were conducted in linear regression models. Results More physiologically-monitored hot flashes during sleep were associated with greater WMH, controlling for age, race, and body mass index [beta(standard error)=.0002 (.0001), p=.03]. Findings persisted controlling for sleep characteristics and additional CVD risk factors. No relations were observed for self-reported hot flashes. Conclusions More physiologically-monitored hot flashes during sleep were associated with greater WMH burden among midlife women free of clinical CVD. Results suggest that relations between hot flashes and CVD risk observed in the periphery may extend to the brain. Future work should consider the unique role of sleep hot flashes in brain health. PMID:26057822

  12. Altered Development of White Matter in Youth at High Familial Risk for Bipolar Disorder: A Diffusion Tensor Imaging Study

    Science.gov (United States)

    Versace, Amelia; Ladouceur, Cecile D.; Romero, Soledad; Birmaher, Boris; Axelson, David A.; Kupfer, David J.; Phillips, Mary L.

    2010-01-01

    Objective: To study white matter (WM) development in youth at high familial risk for bipolar disorder (BD). WM alterations are reported in youth and adults with BD. WM undergoes important maturational changes in adolescence. Age-related changes in WM microstructure using diffusion tensor imaging with tract-based spatial statistics in healthy…

  13. Aerobic fitness is associated with greater white matter integrity in children

    Directory of Open Access Journals (Sweden)

    Laura eChaddock-Heyman

    2014-08-01

    Full Text Available Aerobic fitness has been found to play a positive role in brain and cognitive health of children. Yet, many of the neural biomarkers related to aerobic fitness remain unknown. Here, using diffusion tensor imaging (DTI, we demonstrated that higher aerobic fitness was related to greater estimates of white matter microstructure in children. Higher fit 9- and 10-year-old children showed greater fractional anisotropy (FA in sections of the corpus callosum, corona radiata, and superior longitudinal fasciculus, compared to lower fit children. The FA effects were primarily characterized by aerobic fitness differences in radial diffusivity (RD, thereby raising the possibility that estimates of myelination may vary as a function of individual differences in fitness during childhood. White matter structure may be another potential neural mechanism of aerobic fitness that assists in efficient communication between gray matter regions as well as the integration of regions into networks.

  14. Genetic disorders affecting white matter in the pediatric age.

    Science.gov (United States)

    Di Rocco, Maja; Biancheri, Roberta; Rossi, Andrea; Filocamo, Mirella; Tortori-Donati, Paolo

    2004-08-15

    Pediatric white matter disorders can be distinguished into well-defined leukoencephalopathies, and undefined leukoencephalopathies. The first category may be subdivided into: (a) hypomyelinating disorders; (b) dysmyelinating disorders; (c) leukodystrophies; (d) disorders related to cystic degeneration of myelin; and (e) disorders secondary to axonal damage. The second category, representing up to 50% of leukoencephalopathies in childhood, requires a multidisciplinar approach in order to define novel homogeneous subgroups of patients, possibly representing "new genetic disorders" (such as megalencephalic leukoencepahlopathy with subcortical cysts and vanishing white matter disease that have recently been identified). In the majority of cases, pediatric white matter disorders are inherited diseases. An integrated description of the clinical, neuroimaging and pathophysiological features is crucial for categorizing myelin disorders and better understanding their genetic basis. A review of the genetic disorders affecting white matter in the pediatric age, including some novel entities, is provided. Copyright 2004 Wiley-Liss, Inc.

  15. Pediatric frontal lobe epilepsy : white matter abnormalities and cognitive impairment

    NARCIS (Netherlands)

    Braakman, H.M.H.; Vaessen, M.J.; Jansen, J.F.A.; Debeij-van Hall, M.H.J.A.; Louw, de A.; Hofman, P.A.M.; Vles, J.S.H.; Aldenkamp, A.P.; Backes, W.H.

    2014-01-01

    Objectives: Cognitive impairment is frequent in children with frontal lobe epilepsy (FLE). Its etiology remains unknown. With diffusion tensor imaging, we have studied cerebral white matter properties and associations with cognitive functioning in children with FLE and healthy controls.

  16. Magnetic resonance imaging of white matter diseases of prematurity

    Energy Technology Data Exchange (ETDEWEB)

    Rutherford, Mary A.; Supramaniam, Veena; Ederies, Ashraf; Chew, Andrew; Anjari, Mustafa; Counsell, Serena [Imperial College, Hammersmith Hospital, Robert Steiner MR Unit, MRC Clinical Sciences Centre, London (United Kingdom); Bassi, Laura; Groppo, Michela; Ramenghi, Luca A. [University of Milan, NICU, Institute of Pediatrics and Neonatology, Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena, Milan (Italy)

    2010-06-15

    Periventricular leucomalacia (PVL) and parenchymal venous infarction complicating germinal matrix/intraventricular haemorrhage have long been recognised as the two significant white matter diseases responsible for the majority of cases of cerebral palsy in survivors of preterm birth. However, more recent studies using magnetic resonance imaging to assess the preterm brain have documented two new appearances, adding to the spectrum of white matter disease of prematurity: punctate white matter lesions, and diffuse excessive high signal intensity (DEHSI). These appear to be more common than PVL but less significant in terms of their impact on individual neurodevelopment. They may, however, be associated with later cognitive and behavioural disorders known to be common following preterm birth. It remains unclear whether PVL, punctate lesions, and DEHSI represent a continuum of disorders occurring as a result of a similar injurious process to the developing white matter. This review discusses the role of MR imaging in investigating these three disorders in terms of aetiology, pathology, and outcome. (orig.)

  17. MR imaging of metabolic white matter diseases: Therapeutic response

    International Nuclear Information System (INIS)

    Gebarski, S.S.; Allen, R.

    1987-01-01

    In metabolic diseases affecting the brain, MR imaging abnormalities include white-matter signal aberrations suggesting myelination delay, dysmyelination and demyelination, pathologic iron storage, and finally, loss of substance usually in a nonspecific pattern. The authors suggest that MR imaging may have therapeutic implications: (1) classic galactosemia - white-matter signal aberration became normal after dietary therapy; (2) phenylketonuria - age- and sex-matched treated and nontreated adolescents showed marked differences in brain volume, with the treated patient's volume nearly normal; (3) maple syrup urine disease - gross white-matter signal aberration became nearly normal after dietary therapy; and (4) hyperglycinemia - relentless progression of white-matter signal aberration and loss of brain substance despite therapy. These data suggest that brain MR imaging may provide a therapeutic index in certain metabolic diseases

  18. MR imaging of white matter lesions in AIDS

    International Nuclear Information System (INIS)

    Olsen, W.L.; Longo, F.; Norman, D.

    1987-01-01

    Autopsy reports have shown white-matter abnormalities from infection of the brain by the human immunodeficiency virus (HIV), the agent that causes acquired immunodeficiency syndrome (AIDS). The authors observed abnormal signal on T2-weighted images in the white matter of approximately one third of all AIDS patients. Of 50 patients with white-matter lesions, approximately two thirds had no clinical or biopsy evidence of cytomegalovirus, toxoplasmosis, PML, or lymphoma. Several patients were shown at autopsy to have isolated evidence of HIV encephalitis. The authors conclude that white-matter lesions are common in AIDS and are frequently caused by infection with HIV. Some MR findings may be helpful in characterizing these lesions, but the various etiologies are often indistinguishable

  19. Structural white matter abnormalities in patients with idiopathic dystonia

    NARCIS (Netherlands)

    Bonilha, Leonardo; de Vries, Paulien M.; Vincent, Diana J.; Rorden, Chris; Morgan, Paul S.; Hurd, Mark W.; Besenski, Nada; Bergmann, Kenneth J.; Hinson, Vanessa K.

    2007-01-01

    We investigated whether structural white matter abnormalities, in the form of disruption of axonal coherence and integrity as measured with diffusion tensor imaging (DTI), constitute an underlying pathological mechanism of idiopathic dystonia (ID), independent of genotype status. We studied seven

  20. Genetics Home Reference: leukoencephalopathy with vanishing white matter

    Science.gov (United States)

    ... Torres C, Pröschel C. EIF2B5 mutations compromise GFAP+ astrocyte generation in vanishing white matter leukodystrophy. Nat Med. ... of Medicine Lister Hill National Center for Biomedical Communications 8600 Rockville Pike, Bethesda, MD 20894, USA HONCode ...

  1. In Vivo Evidence of Reduced Integrity of the Gray-White Matter Boundary in Autism Spectrum Disorder.

    Science.gov (United States)

    Andrews, Derek Sayre; Avino, Thomas A; Gudbrandsen, Maria; Daly, Eileen; Marquand, Andre; Murphy, Clodagh M; Lai, Meng-Chuan; Lombardo, Michael V; Ruigrok, Amber N V; Williams, Steven C; Bullmore, Edward T; The Mrc Aims Consortium; Suckling, John; Baron-Cohen, Simon; Craig, Michael C; Murphy, Declan G M; Ecker, Christine

    2017-02-01

    Atypical cortical organization and reduced integrity of the gray-white matter boundary have been reported by postmortem studies in individuals with autism spectrum disorder (ASD). However, there are no in vivo studies that examine these particular features of cortical organization in ASD. Hence, we used structural magnetic resonance imaging to examine differences in tissue contrast between gray and white matter in 98 adults with ASD and 98 typically developing controls, to test the hypothesis that individuals with ASD have significantly reduced tissue contrast. More specifically, we examined contrast as a percentage between gray and white matter tissue signal intensities (GWPC) sampled at the gray-white matter boundary, and across different cortical layers. We found that individuals with ASD had significantly reduced GWPC in several clusters throughout the cortex (cluster, P gray-white matter interface, which indicates a less distinct gray-white matter boundary in ASD. Our in vivo findings of reduced GWPC in ASD are therefore consistent with prior postmortem findings of a less well-defined gray-white matter boundary in ASD. Taken together, these results indicate that GWPC might be utilized as an in vivo proxy measure of atypical cortical microstructural organization in future studies. © The Author 2017. Published by Oxford University Press.

  2. Diminished white matter integrity in patients with systemic lupus erythematosus

    Directory of Open Access Journals (Sweden)

    Tobias Schmidt-Wilcke

    2014-01-01

    Conclusions: Our data suggest that changes in regional white matter integrity, in terms of a decrease in FA, are present not only in NPSLE patients, but also in non-NPSLE patients, though to a lesser degree. We also demonstrate that the way statistical maps are corrected for multiple comparisons has a profound influence on whether alterations in white matter integrity in non-NPSLE patients are deemed significant.

  3. White matter biomarkers from diffusion MRI

    Science.gov (United States)

    Nørhøj Jespersen, Sune

    2018-06-01

    As part of an issue celebrating 2 decades of Joseph Ackerman editing the Journal of Magnetic Resonance, this paper reviews recent progress in one of the many areas in which Ackerman and his lab has made significant contributions: NMR measurement of diffusion in biological media, specifically in brain tissue. NMR diffusion signals display exquisite sensitivity to tissue microstructure, and have the potential to offer quantitative and specific information on the cellular scale orders of magnitude below nominal image resolution when combined with biophysical modeling. Here, I offer a personal perspective on some recent advances in diffusion imaging, from diffusion kurtosis imaging to microstructural modeling, and the connection between the two. A new result on the estimation accuracy of axial and radial kurtosis with axially symmetric DKI is presented. I moreover touch upon recently suggested generalized diffusion sequences, promising to offer independent microstructural information. We discuss the need and some methods for validation, and end with an outlook on some promising future directions.

  4. Effects of Surgery and Proton Therapy on Cerebral White Matter of Craniopharyngioma Patients

    Energy Technology Data Exchange (ETDEWEB)

    Uh, Jinsoo, E-mail: jinsoo.uh@stjude.org [Department of Radiological Sciences, St Jude Children' s Research Hospital, Memphis, Tennessee (United States); Merchant, Thomas E. [Department of Radiological Sciences, St Jude Children' s Research Hospital, Memphis, Tennessee (United States); Li, Yimei; Li, Xingyu [Department of Biostatistics, St Jude Children' s Research Hospital, Memphis, Tennessee (United States); Sabin, Noah D. [Department of Radiological Sciences, St Jude Children' s Research Hospital, Memphis, Tennessee (United States); Indelicato, Daniel J. [Department of Radiation Oncology, University of Florida, Jacksonville, Florida (United States); Ogg, Robert J. [Department of Radiological Sciences, St Jude Children' s Research Hospital, Memphis, Tennessee (United States); Boop, Frederick A. [Semmes-Murphey Neurologic and Spine Institute, Memphis, Tennessee (United States); Jane, John A. [Department of Neurosurgery, University of Virginia, Charlottesville, Virginia (United States); Hua, Chiaho [Department of Radiological Sciences, St Jude Children' s Research Hospital, Memphis, Tennessee (United States)

    2015-09-01

    Purpose: The purpose of this study was to determine radiation dose effect on the structural integrity of cerebral white matter in craniopharyngioma patients receiving surgery and proton therapy. Methods and Materials: Fifty-one patients (2.1-19.3 years of age) with craniopharyngioma underwent surgery and proton therapy in a prospective therapeutic trial. Anatomical magnetic resonance images acquired after surgery but before proton therapy were inspected to identify white matter structures intersected by surgical corridors and catheter tracks. Longitudinal diffusion tensor imaging (DTI) was performed to measure microstructural integrity changes in cerebral white matter. Fractional anisotropy (FA) derived from DTI was statistically analyzed for 51 atlas-based white matter structures of the brain to determine radiation dose effect. FA in surgery-affected regions in the corpus callosum was compared to that in its intact counterpart to determine whether surgical defects affect radiation dose effect. Results: Surgical defects were seen most frequently in the corpus callosum because of transcallosal resection of tumors and insertion of ventricular or cyst catheters. Longitudinal DTI data indicated reductions in FA 3 months after therapy, which was followed by a recovery in most white matter structures. A greater FA reduction was correlated with a higher radiation dose in 20 white matter structures, indicating a radiation dose effect. The average FA in the surgery-affected regions before proton therapy was smaller (P=.0001) than that in their non–surgery-affected counterparts with more intensified subsequent reduction of FA (P=.0083) after therapy, suggesting that surgery accentuated the radiation dose effect. Conclusions: DTI data suggest that mild radiation dose effects occur in patients with craniopharyngioma receiving surgery and proton therapy. Surgical defects present at the time of proton therapy appear to accentuate the radiation dose effect longitudinally

  5. Effects of Surgery and Proton Therapy on Cerebral White Matter of Craniopharyngioma Patients

    International Nuclear Information System (INIS)

    Uh, Jinsoo; Merchant, Thomas E.; Li, Yimei; Li, Xingyu; Sabin, Noah D.; Indelicato, Daniel J.; Ogg, Robert J.; Boop, Frederick A.; Jane, John A.; Hua, Chiaho

    2015-01-01

    Purpose: The purpose of this study was to determine radiation dose effect on the structural integrity of cerebral white matter in craniopharyngioma patients receiving surgery and proton therapy. Methods and Materials: Fifty-one patients (2.1-19.3 years of age) with craniopharyngioma underwent surgery and proton therapy in a prospective therapeutic trial. Anatomical magnetic resonance images acquired after surgery but before proton therapy were inspected to identify white matter structures intersected by surgical corridors and catheter tracks. Longitudinal diffusion tensor imaging (DTI) was performed to measure microstructural integrity changes in cerebral white matter. Fractional anisotropy (FA) derived from DTI was statistically analyzed for 51 atlas-based white matter structures of the brain to determine radiation dose effect. FA in surgery-affected regions in the corpus callosum was compared to that in its intact counterpart to determine whether surgical defects affect radiation dose effect. Results: Surgical defects were seen most frequently in the corpus callosum because of transcallosal resection of tumors and insertion of ventricular or cyst catheters. Longitudinal DTI data indicated reductions in FA 3 months after therapy, which was followed by a recovery in most white matter structures. A greater FA reduction was correlated with a higher radiation dose in 20 white matter structures, indicating a radiation dose effect. The average FA in the surgery-affected regions before proton therapy was smaller (P=.0001) than that in their non–surgery-affected counterparts with more intensified subsequent reduction of FA (P=.0083) after therapy, suggesting that surgery accentuated the radiation dose effect. Conclusions: DTI data suggest that mild radiation dose effects occur in patients with craniopharyngioma receiving surgery and proton therapy. Surgical defects present at the time of proton therapy appear to accentuate the radiation dose effect longitudinally

  6. Deficits in Neurite Density Underlie White Matter Structure Abnormalities in First-Episode Psychosis.

    Science.gov (United States)

    Rae, Charlotte L; Davies, Geoff; Garfinkel, Sarah N; Gabel, Matt C; Dowell, Nicholas G; Cercignani, Mara; Seth, Anil K; Greenwood, Kathryn E; Medford, Nick; Critchley, Hugo D

    2017-11-15

    Structural abnormalities across multiple white matter tracts are recognized in people with early psychosis, consistent with dysconnectivity as a neuropathological account of symptom expression. We applied advanced neuroimaging techniques to characterize microstructural white matter abnormalities for a deeper understanding of the developmental etiology of psychosis. Thirty-five first-episode psychosis patients, and 19 healthy controls, participated in a quantitative neuroimaging study using neurite orientation dispersion and density imaging, a multishell diffusion-weighted magnetic resonance imaging technique that distinguishes white matter fiber arrangement and geometry from changes in neurite density. Fractional anisotropy (FA) and mean diffusivity images were also derived. Tract-based spatial statistics compared white matter structure between patients and control subjects and tested associations with age, symptom severity, and medication. Patients with first-episode psychosis had lower regional FA in multiple commissural, corticospinal, and association tracts. These abnormalities predominantly colocalized with regions of reduced neurite density, rather than aberrant fiber bundle arrangement (orientation dispersion index). There was no direct relationship with active symptoms. FA decreased and orientation dispersion index increased with age in patients, but not control subjects, suggesting accelerated effects of white matter geometry change. Deficits in neurite density appear fundamental to abnormalities in white matter integrity in early psychosis. In the first application of neurite orientation dispersion and density imaging in psychosis, we found that processes compromising axonal fiber number, density, and myelination, rather than processes leading to spatial disruption of fiber organization, are implicated in the etiology of psychosis. This accords with a neurodevelopmental origin of aberrant brain-wide structural connectivity predisposing individuals to

  7. Effect of Simulated Microgravity on Human Brain Gray Matter and White Matter--Evidence from MRI.

    Directory of Open Access Journals (Sweden)

    Ke Li

    Full Text Available There is limited and inconclusive evidence that space environment, especially microgravity condition, may affect microstructure of human brain. This experiment hypothesized that there would be modifications in gray matter (GM and white matter (WM of the brain due to microgravity.Eighteen male volunteers were recruited and fourteen volunteers underwent -6° head-down bed rest (HDBR for 30 days simulated microgravity. High-resolution brain anatomical imaging data and diffusion tensor imaging images were collected on a 3T MR system before and after HDBR. We applied voxel-based morphometry and tract-based spatial statistics analysis to investigate the structural changes in GM and WM of brain.We observed significant decreases of GM volume in the bilateral frontal lobes, temporal poles, parahippocampal gyrus, insula and right hippocampus, and increases of GM volume in the vermis, bilateral paracentral lobule, right precuneus gyrus, left precentral gyrus and left postcentral gyrus after HDBR. Fractional anisotropy (FA changes were also observed in multiple WM tracts.These regions showing GM changes are closely associated with the functional domains of performance, locomotion, learning, memory and coordination. Regional WM alterations may be related to brain function decline and adaption. Our findings provide the neuroanatomical evidence of brain dysfunction or plasticity in microgravity condition and a deeper insight into the cerebral mechanisms in microgravity condition.

  8. In vivo characterization of cortical and white matter neuroaxonal pathology in early multiple sclerosis.

    Science.gov (United States)

    Granberg, Tobias; Fan, Qiuyun; Treaba, Constantina Andrada; Ouellette, Russell; Herranz, Elena; Mangeat, Gabriel; Louapre, Céline; Cohen-Adad, Julien; Klawiter, Eric C; Sloane, Jacob A; Mainero, Caterina

    2017-11-01

    Neuroaxonal pathology is a main determinant of disease progression in multiple sclerosis; however, its underlying pathophysiological mechanisms, including its link to inflammatory demyelination and temporal occurrence in the disease course are still unknown. We used ultra-high field (7 T), ultra-high gradient strength diffusion and T1/T2-weighted myelin-sensitive magnetic resonance imaging to characterize microstructural changes in myelin and neuroaxonal integrity in the cortex and white matter in early stage multiple sclerosis, their distribution in lesional and normal-appearing tissue, and their correlations with neurological disability. Twenty-six early stage multiple sclerosis subjects (disease duration ≤5 years) and 24 age-matched healthy controls underwent 7 T T2*-weighted imaging for cortical lesion segmentation and 3 T T1/T2-weighted myelin-sensitive imaging and neurite orientation dispersion and density imaging for assessing microstructural myelin, axonal and dendrite integrity in lesional and normal-appearing tissue of the cortex and the white matter. Conventional mean diffusivity and fractional anisotropy metrics were also assessed for comparison. Cortical lesions were identified in 92% of early multiple sclerosis subjects and they were characterized by lower intracellular volume fraction (P = 0.015 by paired t-test), lower myelin-sensitive contrast (P = 0.030 by related-samples Wilcoxon signed-rank test) and higher mean diffusivity (P = 0.022 by related-samples Wilcoxon signed-rank test) relative to the contralateral normal-appearing cortex. Similar findings were observed in white matter lesions relative to normal-appearing white matter (all P test) and lower fractional anisotropy (P Wilcoxon signed-rank test) suggestive of less coherent underlying fibre orientation. Additionally, the normal-appearing white matter in multiple sclerosis subjects had diffusely lower intracellular volume fractions than the white matter in controls (P = 0.029 by unpaired

  9. Correlation between white matter damage and gray matter lesions in multiple sclerosis patients

    Directory of Open Access Journals (Sweden)

    Xue-mei Han

    2017-01-01

    Full Text Available We observed the characteristics of white matter fibers and gray matter in multiple sclerosis patients, to identify changes in diffusion tensor imaging fractional anisotropy values following white matter fiber injury. We analyzed the correlation between fractional anisotropy values and changes in whole-brain gray matter volume. The participants included 20 patients with relapsing-remitting multiple sclerosis and 20 healthy volunteers as controls. All subjects underwent head magnetic resonance imaging and diffusion tensor imaging. Our results revealed that fractional anisotropy values decreased and gray matter volumes were reduced in the genu and splenium of corpus callosum, left anterior thalamic radiation, hippocampus, uncinate fasciculus, right corticospinal tract, bilateral cingulate gyri, and inferior longitudinal fasciculus in multiple sclerosis patients. Gray matter volumes were significantly different between the two groups in the right frontal lobe (superior frontal, middle frontal, precentral, and orbital gyri, right parietal lobe (postcentral and inferior parietal gyri, right temporal lobe (caudate nucleus, right occipital lobe (middle occipital gyrus, right insula, right parahippocampal gyrus, and left cingulate gyrus. The voxel sizes of atrophic gray matter positively correlated with fractional anisotropy values in white matter association fibers in the patient group. These findings suggest that white matter fiber bundles are extensively injured in multiple sclerosis patients. The main areas of gray matter atrophy in multiple sclerosis are the frontal lobe, parietal lobe, caudate nucleus, parahippocampal gyrus, and cingulate gyrus. Gray matter atrophy is strongly associated with white matter injury in multiple sclerosis patients, particularly with injury to association fibers.

  10. In vivo evidence of cerebellar atrophy and cerebral white matter loss in Huntington disease

    DEFF Research Database (Denmark)

    Fennema-Notestine, C; Archibald, S.L.; Jacobsen, M.W.

    2004-01-01

    and education. Primary analyses defined six subcortical regions, the gray and white matter of primary cortical lobes and cerebellum, and abnormal signal in the cerebral white matter. RESULTS: As expected, basal ganglia and cerebral cortical gray matter volumes were significantly smaller in HD. The HD group also...... demonstrated significant cerebral white matter loss and an increase in the amount of abnormal signal in the white matter; occipital white matter appeared more affected than other cerebral white matter regions. Cortical gray and white matter measures were significantly related to caudate volume. Cerebellar gray...

  11. White Matter Features Associated With Autistic Traits in Obsessive-Compulsive Disorder

    Directory of Open Access Journals (Sweden)

    Masaru Kuno

    2018-05-01

    Full Text Available Obsessive-compulsive disorder (OCD is among the most debilitating psychiatric disorders. Comorbid autism spectrum disorder (ASD or autistic traits may impair treatment response in OCD. To identify possible neurostructural deficits underlying autistic traits, we performed white matter tractography on diffusion tensor images (DTI and assessed autistic trait severity using the Autism-Spectrum Quotient (AQ in 33 OCD patients. Correlations between AQ and the DTI parameters, fractional anisotropy (FA, mean diffusivity (MD, axial diffusivity (AD, and radial diffusivity (RD were examined in major white matter tracts that were suggested to be altered in previous OCD studies. We found a negative correlation between AQ and FA and positive correlations between AQ and MD, AD and RD in the left uncinate fasciculus using age, Beck Depression Inventory, Yale-Brown Obsessive-Compulsive Scale, intelligence quotient and medication as covariates. However, we could not detect the significant results between AQ and all DTI parameters when adding gender as a covariate. In addition, in the ASD comorbid group, FA in the left uncinate fasciculus was significantly lower than in the non-ASD comorbid group and MD and RD were significantly higher than in the non-ASD group. These results did not survive correction for multiple comparisons. In ASD, the socio-emotional dysfunction is suggested to be related to the alteration of white matter microstructure in uncinate fasciculus. Our results suggest that variations in white matter features of the left uncinate fasciculus might be partly explained by autistic traits encountered in OCD patients.

  12. Exploratory analysis of diffusion tensor imaging in children with attention deficit hyperactivity disorder: evidence of abnormal white matter structure.

    Science.gov (United States)

    Pastura, Giuseppe; Doering, Thomas; Gasparetto, Emerson Leandro; Mattos, Paulo; Araújo, Alexandra Prüfer

    2016-06-01

    Abnormalities in the white matter microstructure of the attentional system have been implicated in the aetiology of attention deficit hyperactivity disorder (ADHD). Diffusion tensor imaging (DTI) is a promising magnetic resonance imaging (MRI) technology that has increasingly been used in studies of white matter microstructure in the brain. The main objective of this work was to perform an exploratory analysis of white matter tracts in a sample of children with ADHD versus typically developing children (TDC). For this purpose, 13 drug-naive children with ADHD of both genders underwent MRI using DTI acquisition methodology and tract-based spatial statistics. The results were compared to those of a sample of 14 age- and gender-matched TDC. Lower fractional anisotropy was observed in the splenium of the corpus callosum, right superior longitudinal fasciculus, bilateral retrolenticular part of the internal capsule, bilateral inferior fronto-occipital fasciculus, left external capsule and posterior thalamic radiation (including right optic radiation). We conclude that white matter tracts in attentional and motor control systems exhibited signs of abnormal microstructure in this sample of drug-naive children with ADHD.

  13. Normal frontal lobe gray matter-white matter CT volume ratio in children

    International Nuclear Information System (INIS)

    Thompson, J.R.; Engelhart, J.; Hasso, A.N.; Hinshaw, D.B. Jr.

    1985-01-01

    We attempted to establish a computed tomographic value representing the normal volume ratio of gray matter to white matter (G/W) in children in order to have a baseline for studying various developmental disorders such as white matter hypoplasia. The records of 150 children 16 years of age or younger who had normal cranial computed tomography were reviewed. From these a group of 119 were excluded for various reasons. The remaining 3 were presumed to have normal brains. Using the region of interest function for tracing gray and white matter boundaries, superior and ventral to the foramen of Munro area, measurements were determined for consecutive adjacent frontal slices. Volumes were then calculated for both gray and white matter. A volume ratio of 2.010 (sigma=0.349), G/W, was then derived from each of 31 children. The clinical value of this ratio will be determined by future investigation. (orig.)

  14. Age-related cerebral white matter changes on computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Hitoshi; Kobayashi, Shotai; Koide, Hiromi; Yamaguchi, Shuhei; Okada, Kazunori; Shimote, Kouichi; Tsunematsu, Tokugoro

    1989-01-01

    Changes of cerebral white matter on computed cranial tomography related to aging were studied in 70 subjects aged 30 to 94 years. The subjects had no histories of cerebrovascular accidents and no abnormalities in the central nervous system were shown by physical examinations and CT scans. We measured the average attenuation values (CT numbers) of each elliptical region (165 pixels, 0.39cm/sup 2/) in the bilateral thalamus and twelve areas of deep white matter. Multiple regression analysis was used to assess the effects of age, cranial size and cranial bone CT numbers on the brain CT numbers. We also studied the association between brain CT numbers and brain atrophy, hypertension, diabetes mellitus. CT numbers of frontal white matter surrounding anterior horns decreased with aging in 70 subjects aged 30 to 94 years. No significant correlation between age and brain CT numbers was found in any other region by multivariate analysis, because of the prominent effect of cranial bone CT numbers on brain CT numbers. Although no age-related changes of white matter CT numbers was found in 41 subjects aged 30 to 65 years, there were significant negative correlations between age and white matter CT numbers at all regions in 29 subjects aged 66 to 94 years. Brain atrophy was associated with brain CT numbers. No association was found for hypertension or diabetes mellitus. Brain CT numbers decreased with aging even in neurologically healthy persons in older age. Brain CT numbers also decreased as cerebral atrophy advanced. (author).

  15. Age-related cerebral white matter changes on computed tomography

    International Nuclear Information System (INIS)

    Fukuda, Hitoshi; Kobayashi, Shotai; Koide, Hiromi; Yamaguchi, Shuhei; Okada, Kazunori; Shimote, Kouichi; Tsunematsu, Tokugoro

    1989-01-01

    Changes of cerebral white matter on computed cranial tomography related to aging were studied in 70 subjects aged 30 to 94 years. The subjects had no histories of cerebrovascular accidents and no abnormalities in the central nervous system were shown by physical examinations and CT scans. We measured the average attenuation values (CT numbers) of each elliptical region (165 pixels, 0.39cm 2 ) in the bilateral thalamus and twelve areas of deep white matter. Multiple regression analysis was used to assess the effects of age, cranial size and cranial bone CT numbers on the brain CT numbers. We also studied the association between brain CT numbers and brain atrophy, hypertension, diabetes mellitus. CT numbers of frontal white matter surrounding anterior horns decreased with aging in 70 subjects aged 30 to 94 years. No significant correlation between age and brain CT numbers was found in any other region by multivariate analysis, because of the prominent effect of cranial bone CT numbers on brain CT numbers. Although no age-related changes of white matter CT numbers was found in 41 subjects aged 30 to 65 years, there were significant negative correlations between age and white matter CT numbers at all regions in 29 subjects aged 66 to 94 years. Brain atrophy was associated with brain CT numbers. No association was found for hypertension or diabetes mellitus. Brain CT numbers decreased with aging even in neurologically healthy persons in older age. Brain CT numbers also decreased as cerebral atrophy advanced. (author)

  16. White matter integrity in veterans with mild traumatic brain injury: associations with executive function and loss of consciousness.

    Science.gov (United States)

    Sorg, Scott F; Delano-Wood, Lisa; Luc, Norman; Schiehser, Dawn M; Hanson, Karen L; Nation, Daniel A; Lanni, Elisa; Jak, Amy J; Lu, Kun; Meloy, M J; Frank, Lawrence R; Lohr, James B; Bondi, Mark W

    2014-01-01

    We investigated using diffusion tensor imaging (DTI) and the association between white matter integrity and executive function (EF) performance in postacute mild traumatic brain injury (mTBI). In addition, we examined whether injury severity, as measured by loss of consciousness (LOC) versus alterations in consciousness (AOC), is related to white matter microstructural alterations and neuropsychological outcome. Thirty Iraq and Afghanistan War era veterans with a history of mTBI and 15 healthy veteran control participants. There were no significant overall group differences between control and mTBI participants on DTI measures. However, a subgroup of mTBI participants with EF decrements (n = 13) demonstrated significantly decreased fractional anisotropy of prefrontal white matter, corpus callosum, and cingulum bundle structures compared with mTBI participants without EF decrements (n = 17) and control participants. Participants having mTBI with LOC were more likely to evidence reduced EF performances and disrupted ventral prefrontal white matter integrity when compared with either mTBI participants without LOC or control participants. Findings suggest that altered white matter integrity contributes to reduced EF in subgroups of veterans with a history of mTBI and that LOC may be a risk factor for reduced EF as well as associated changes to ventral prefrontal white matter.

  17. The Plasticity of Brain Gray Matter and White Matter following Lower Limb Amputation

    Directory of Open Access Journals (Sweden)

    Guangyao Jiang

    2015-01-01

    Full Text Available Accumulating evidence has indicated that amputation induces functional reorganization in the sensory and motor cortices. However, the extent of structural changes after lower limb amputation in patients without phantom pain remains uncertain. We studied 17 adult patients with right lower limb amputation and 18 healthy control subjects using T1-weighted magnetic resonance imaging and diffusion tensor imaging. Cortical thickness and fractional anisotropy (FA of white matter (WM were investigated. In amputees, a thinning trend was seen in the left premotor cortex (PMC. Smaller clusters were also noted in the visual-to-motor regions. In addition, the amputees also exhibited a decreased FA in the right superior corona radiata and WM regions underlying the right temporal lobe and left PMC. Fiber tractography from these WM regions showed microstructural changes in the commissural fibers connecting the bilateral premotor cortices, compatible with the hypothesis that amputation can lead to a change in interhemispheric interactions. Finally, the lower limb amputees also displayed significant FA reduction in the right inferior frontooccipital fasciculus, which is negatively correlated with the time since amputation. In conclusion, our findings indicate that the amputation of lower limb could induce changes in the cortical representation of the missing limb and the underlying WM connections.

  18. Scalable Brain Network Construction on White Matter Fibers.

    Science.gov (United States)

    Chung, Moo K; Adluru, Nagesh; Dalton, Kim M; Alexander, Andrew L; Davidson, Richard J

    2011-02-12

    DTI offers a unique opportunity to characterize the structural connectivity of the human brain non-invasively by tracing white matter fiber tracts. Whole brain tractography studies routinely generate up to half million tracts per brain, which serves as edges in an extremely large 3D graph with up to half million edges. Currently there is no agreed-upon method for constructing the brain structural network graphs out of large number of white matter tracts. In this paper, we present a scalable iterative framework called the ε-neighbor method for building a network graph and apply it to testing abnormal connectivity in autism.

  19. Altered Gray Matter Volume and White Matter Integrity in College Students with Mobile Phone Dependence.

    Science.gov (United States)

    Wang, Yongming; Zou, Zhiling; Song, Hongwen; Xu, Xiaodan; Wang, Huijun; d'Oleire Uquillas, Federico; Huang, Xiting

    2016-01-01

    Mobile phone dependence (MPD) is a behavioral addiction that has become an increasing public mental health issue. While previous research has explored some of the factors that may predict MPD, the underlying neural mechanisms of MPD have not been investigated yet. The current study aimed to explore the microstructural variations associated with MPD as measured with functional Magnetic Resonance Imaging (fMRI). Gray matter volume (GMV) and white matter (WM) integrity [four indices: fractional anisotropy (FA); mean diffusivity (MD); axial diffusivity (AD); and radial diffusivity (RD)] were calculated via voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) analysis, respectively. Sixty-eight college students (42 female) were enrolled and separated into two groups [MPD group, N = 34; control group (CG), N = 34] based on Mobile Phone Addiction Index (MPAI) scale score. Trait impulsivity was also measured using the Barratt Impulsiveness Scale (BIS-11). In light of underlying trait impulsivity, results revealed decreased GMV in the MPD group relative to controls in regions such as the right superior frontal gyrus (sFG), right inferior frontal gyrus (iFG), and bilateral thalamus (Thal). In the MPD group, GMV in the above mentioned regions was negatively correlated with scores on the MPAI. Results also showed significantly less FA and AD measures of WM integrity in the MPD group relative to controls in bilateral hippocampal cingulum bundle fibers (CgH). Additionally, in the MPD group, FA of the CgH was also negatively correlated with scores on the MPAI. These findings provide the first morphological evidence of altered brain structure with mobile phone overuse, and may help to better understand the neural mechanisms of MPD in relation to other behavioral and substance addiction disorders.

  20. Altered Gray Matter Volume and White Matter Integrity in College Students with Mobile Phone Dependence

    Science.gov (United States)

    Wang, Yongming; Zou, Zhiling; Song, Hongwen; Xu, Xiaodan; Wang, Huijun; d’Oleire Uquillas, Federico; Huang, Xiting

    2016-01-01

    Mobile phone dependence (MPD) is a behavioral addiction that has become an increasing public mental health issue. While previous research has explored some of the factors that may predict MPD, the underlying neural mechanisms of MPD have not been investigated yet. The current study aimed to explore the microstructural variations associated with MPD as measured with functional Magnetic Resonance Imaging (fMRI). Gray matter volume (GMV) and white matter (WM) integrity [four indices: fractional anisotropy (FA); mean diffusivity (MD); axial diffusivity (AD); and radial diffusivity (RD)] were calculated via voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) analysis, respectively. Sixty-eight college students (42 female) were enrolled and separated into two groups [MPD group, N = 34; control group (CG), N = 34] based on Mobile Phone Addiction Index (MPAI) scale score. Trait impulsivity was also measured using the Barratt Impulsiveness Scale (BIS-11). In light of underlying trait impulsivity, results revealed decreased GMV in the MPD group relative to controls in regions such as the right superior frontal gyrus (sFG), right inferior frontal gyrus (iFG), and bilateral thalamus (Thal). In the MPD group, GMV in the above mentioned regions was negatively correlated with scores on the MPAI. Results also showed significantly less FA and AD measures of WM integrity in the MPD group relative to controls in bilateral hippocampal cingulum bundle fibers (CgH). Additionally, in the MPD group, FA of the CgH was also negatively correlated with scores on the MPAI. These findings provide the first morphological evidence of altered brain structure with mobile phone overuse, and may help to better understand the neural mechanisms of MPD in relation to other behavioral and substance addiction disorders. PMID:27199831

  1. Linking white matter and deep gray matter alterations in premanifest Huntington disease

    Directory of Open Access Journals (Sweden)

    Andreia V. Faria

    2016-01-01

    Full Text Available Huntington disease (HD is a fatal progressive neurodegenerative disorder for which only symptomatic treatment is available. A better understanding of the pathology, and identification of biomarkers will facilitate the development of disease-modifying treatments. HD is potentially a good model of a neurodegenerative disease for development of biomarkers because it is an autosomal-dominant disease with complete penetrance, caused by a single gene mutation, in which the neurodegenerative process can be assessed many years before onset of signs and symptoms of manifest disease. Previous MRI studies have detected abnormalities in gray and white matter starting in premanifest stages. However, the understanding of how these abnormalities are related, both in time and space, is still incomplete. In this study, we combined deep gray matter shape diffeomorphometry and white matter DTI analysis in order to provide a better mapping of pathology in the deep gray matter and subcortical white matter in premanifest HD. We used 296 MRI scans from the PREDICT-HD database. Atrophy in the deep gray matter, thalamus, hippocampus, and nucleus accumbens was analyzed by surface based morphometry, and while white matter abnormalities were analyzed in (i regions of interest surrounding these structures, using (ii tractography-based analysis, and using (iii whole brain atlas-based analysis. We detected atrophy in the deep gray matter, particularly in putamen, from early premanifest stages. The atrophy was greater both in extent and effect size in cases with longer exposure to the effects of the CAG expansion mutation (as assessed by greater CAP-scores, and preceded detectible abnormalities in the white matter. Near the predicted onset of manifest HD, the MD increase was widespread, with highest indices in the deep and posterior white matter. This type of in-vivo macroscopic mapping of HD brain abnormalities can potentially indicate when and where therapeutics could be

  2. Lower digit symbol substitution score in the oldest old is related to magnetization transfer and diffusion tensor imaging of the white matter.

    Directory of Open Access Journals (Sweden)

    Vijay eVenkatraman

    2011-09-01

    Full Text Available Background: Slowing information processing is common among community-dwelling elderly and it predicts greater mortality and disability risk. Slowing information processing is related to brain macro-structural abnormalities. Specifically, greater global atrophy and greater small vessel disease of the white matter have been associated to slower processing speed. However, community-dwelling elderly with such macro-structural abnormalities can maintain processing speed. The roles of brain micro-structure for slow processing in very old adults living in the community is uncertain, as epidemiological studies relating these brain markers to cognition and in the context of other health characteristics are sparse. Hypothesis: Information processing is cross-sectionally associated with white matter micro-structure independent of overt macro-structural abnormalities and also independent of health related characteristics. Methods: Imaging indices of micro-structure (diffusion tensor imaging, DTI, and magnetization transfer imaging, MTI, macro-structure (white matter hyperintensities, gray matter volume, Digit Symbol Substitution Test (DSST and health characteristics were measured in 272 elderly (mean age 83 years old, 43% men, 40% Black living in the community. Results: The DTI- and MTI-indices of micro-structure from the normal appearing white matter and not from the normal appearing gray matter were associated with DSST score independent of white matter hyperintensities and gray matter volumes. Associations were also independent of age, race, gender, mini-mental score, systolic blood pressure, prevalent myocardial infarction. Interpretation: DTI and MTI indices of normal appearing white matter are indicators of information processing speed in this cohort of very old adults living in the community. Since processing slowing is a potent index of mortality and disability, these indices may serve as biomarkers in prevention or treatment trials of disability.

  3. AGREEMENT BETWEEN THE WHITE MATTER CONNECTIVITY BASED ON THE TENSOR-BASED MORPHOMETRY AND THE VOLUMETRIC WHITE MATTER PARCELLATIONS BASED ON DIFFUSION TENSOR IMAGING

    OpenAIRE

    Kim, Seung-Goo; Lee, Hyekyoung; Chung, Moo K.; Hanson, Jamie L.; Avants, Brian B.; Gee, James C.; Davidson, Richard J.; Pollak, Seth D.

    2012-01-01

    We are interested in investigating white matter connectivity using a novel computational framework that does not use diffusion tensor imaging (DTI) but only uses T1-weighted magnetic resonance imaging. The proposed method relies on correlating Jacobian determinants across different voxels based on the tensor-based morphometry (TBM) framework. In this paper, we show agreement between the TBM-based white matter connectivity and the DTI-based white matter atlas. As an application, altered white ...

  4. Spatial characteristics of white matter abnormalities in schizophrenia

    NARCIS (Netherlands)

    T.J.H. White (Tonya); S.M. Ehrlich (Stefan); B.C. Ho (Beng ); D.S. Manoach (Dara); A. Caprihan (Arvind); S.C. Schulz (S. Charles); N.C. Andreasen; R.L. Gollub (Randy); V.D. Calhoun (Vince); V. Magnotta

    2013-01-01

    textabstractThere is considerable evidence implicating brain white matter (WM) abnormalities in the pathophysiology of schizophrenia; however, the spatial localization of WM abnormalities reported in the existing studies is heterogeneous. Thus, the goal of this study was to quantify the spatial

  5. White Matter Volume Predicts Language Development in Congenital Heart Disease.

    Science.gov (United States)

    Rollins, Caitlin K; Asaro, Lisa A; Akhondi-Asl, Alireza; Kussman, Barry D; Rivkin, Michael J; Bellinger, David C; Warfield, Simon K; Wypij, David; Newburger, Jane W; Soul, Janet S

    2017-02-01

    To determine whether brain volume is reduced at 1 year of age and whether these volumes are associated with neurodevelopment in biventricular congenital heart disease (CHD) repaired in infancy. Infants with biventricular CHD (n = 48) underwent brain magnetic resonance imaging (MRI) and neurodevelopmental testing with the Bayley Scales of Infant Development-II and the MacArthur-Bates Communicative Development Inventories at 1 year of age. A multitemplate based probabilistic segmentation algorithm was applied to volumetric MRI data. We compared volumes with those of 13 healthy control infants of comparable ages. In the group with CHD, we measured Spearman correlations between neurodevelopmental outcomes and the residuals from linear regression of the volumes on corrected chronological age at MRI and sex. Compared with controls, infants with CHD had reductions of 54 mL in total brain (P = .009), 40 mL in cerebral white matter (P Development-II scores but did correlate positively with MacArthur-Bates Communicative Development Inventory language development. Infants with biventricular CHD show total brain volume reductions at 1 year of age, driven by differences in cerebral white matter. White matter volume correlates with language development, but not broader developmental indices. These findings suggest that abnormalities in white matter development detected months after corrective heart surgery may contribute to language impairment. ClinicalTrials.gov: NCT00006183. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Visualizing White Matter Structure of the Brain using Dijkstra's Algorithm

    NARCIS (Netherlands)

    Everts, Maarten H.; Bekker, Henk; Roerdink, Jos B. T. M.; Zinterhof, P; Loncaric, S; Uhl, A; Carini, A

    2009-01-01

    An undirected weighted graph may be constructed from diffusion weighted magnetic resonance imaging data. Every node represents a voxel and the edge weights between nodes represent the white matter connectivity between neighboring voxels. In this paper we propose and test a new method for calculating

  7. White Matter Damage and Cognitive Impairment after Traumatic Brain Injury

    Science.gov (United States)

    Kinnunen, Kirsi Maria; Greenwood, Richard; Powell, Jane Hilary; Leech, Robert; Hawkins, Peter Charlie; Bonnelle, Valerie; Patel, Maneesh Chandrakant; Counsell, Serena Jane; Sharp, David James

    2011-01-01

    White matter disruption is an important determinant of cognitive impairment after brain injury, but conventional neuroimaging underestimates its extent. In contrast, diffusion tensor imaging provides a validated and sensitive way of identifying the impact of axonal injury. The relationship between cognitive impairment after traumatic brain injury…

  8. Bilirubin and its oxidation products damage brain white matter

    Science.gov (United States)

    Lakovic, Katarina; Ai, Jinglu; D'Abbondanza, Josephine; Tariq, Asma; Sabri, Mohammed; Alarfaj, Abdullah K; Vasdev, Punarjot; Macdonald, Robert Loch

    2014-01-01

    Brain injury after intracerebral hemorrhage (ICH) occurs in cortex and white matter and may be mediated by blood breakdown products, including hemoglobin and heme. Effects of blood breakdown products, bilirubin and bilirubin oxidation products, have not been widely investigated in adult brain. Here, we first determined the effect of bilirubin and its oxidation products on the structure and function of white matter in vitro using brain slices. Subsequently, we determined whether these compounds have an effect on the structure and function of white matter in vivo. In all, 0.5 mmol/L bilirubin treatment significantly damaged both the function and the structure of myelinated axons but not the unmyelinated axons in brain slices. Toxicity of bilirubin in vitro was prevented by dimethyl sulfoxide. Bilirubin oxidation products (BOXes) may be responsible for the toxicity of bilirubin. In in vivo experiments, unmyelinated axons were found more susceptible to damage from bilirubin injection. These results suggest that unmyelinated axons may have a major role in white-matter damage in vivo. Since bilirubin and BOXes appear in a delayed manner after ICH, preventing their toxic effects may be worth investigating therapeutically. Dimethyl sulfoxide or its structurally related derivatives may have a potential therapeutic value at antagonizing axonal damage after hemorrhagic stroke. PMID:25160671

  9. Early dynamics of white matter deficits in children developing dyslexia.

    Science.gov (United States)

    Vanderauwera, Jolijn; Wouters, Jan; Vandermosten, Maaike; Ghesquière, Pol

    2017-10-01

    Neural anomalies have been demonstrated in dyslexia. Recent studies in pre-readers at risk for dyslexia and in pre-readers developing poor reading suggest that these anomalies might be a cause of their reading impairment. Our study goes one step further by exploring the neurodevelopmental trajectory of white matter anomalies in pre-readers with and without a familial risk for dyslexia (n=61) of whom a strictly selected sample develops dyslexia later on (n=15). We collected longitudinal diffusion MRI and behavioural data until grade 3. The results provide evidence that children with dyslexia exhibit pre-reading white matter anomalies in left and right long segment of the arcuate fasciculus (AF), with predictive power of the left segment above traditional cognitive measures and familial risk. Whereas white matter differences in the left AF seem most strongly related to the development of dyslexia, differences in the left IFOF and in the right AF seem driven by both familial risk and later reading ability. Moreover, differences in the left AF appeared to be dynamic. This study supports and expands recent insights into the neural basis of dyslexia, pointing towards pre-reading anomalies related to dyslexia, as well as underpinning the dynamic character of white matter. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Non-pharmacological modulation of cerebral white matter organization

    DEFF Research Database (Denmark)

    Kristensen, Tina D; Mandl, Rene C W; Jepsen, Jens R M

    2018-01-01

    OBJECTIVE: Neuroplasticity is a well-described phenomenon, but effects of non-pharmacological interventions on white matter (WM) are unclear. Here we review associations between active non-pharmacological interventions and WM organization in healthy subjects and in psychiatric patients. METHOD...

  11. Paradoxical embolisation and cerebral white matter lesions in dementia.

    NARCIS (Netherlands)

    Purandare, N.; Oude Voshaar, R.C.; McCollum, C.; Jackson, A.; Burns, A.

    2008-01-01

    The study aimed to examine the relationship between spontaneous cerebral emboli (SCE), patent foramen ovale (PFO) and white matter hyperintensities (WMH) on cerebral MRI in patients with Alzheimer's disease (AD) and vascular dementia (VaD). SCE were identified by transcranial Doppler of the middle

  12. White matter tract integrity in treatment-resistant gambling disorder

    DEFF Research Database (Denmark)

    Chamberlain, Samuel R.; Derbyshire, Katherine; Daws, Richard E.

    2016-01-01

    Background: Gambling disorder is a relatively common psychiatric disorder recently re-classified within the DSM-5 under the category of ‘substance-related and addictive disorders’. Aims: To compare white matter integrity in patients with gambling disorder with healthy controls; to explore...

  13. White matter structural connectivity and episodic memory in early childhood

    Directory of Open Access Journals (Sweden)

    Chi T. Ngo

    2017-12-01

    Full Text Available Episodic memory undergoes dramatic improvement in early childhood; the reason for this is poorly understood. In adults, episodic memory relies on a distributed neural network. Key brain regions that supporting these processes include the hippocampus, portions of the parietal cortex, and portions of prefrontal cortex, each of which shows different developmental profiles. Here we asked whether developmental differences in the axonal pathways connecting these regions may account for the robust gains in episodic memory in young children. Using diffusion weighted imaging, we examined whether white matter connectivity between brain regions implicated in episodic memory differed with age, and were associated with memory performance differences in 4- and 6-year-old children. Results revealed that white matter connecting the hippocampus to the inferior parietal lobule significantly predicted children’s performance on episodic memory tasks. In contrast, variation in the white matter connecting the hippocampus to the medial prefrontal cortex did not relate to memory performance. These findings suggest that structural connectivity between the hippocampus and lateral parietal regions is relevant to the development of episodic memory. Keywords: White matter, Memory development, Episodic memory, Diffusion weighted imaging

  14. White matter hyperintensities and working memory : An explorative study

    NARCIS (Netherlands)

    van Harten, Barbera; Weinstein, Henry C.; Scheltens, Philip; Sergeant, Joseph A.; Scherder, Erik J. A.; Oosterman, J

    2008-01-01

    White matter hyperintensities (WMH) are commonly observed in elderly people and may have the most profound effect on executive functions, including working memory. Surprisingly, the Digit Span backward, a frequently employed working memory task, reveals no association with WMH. In the present study,

  15. Early and extensive spinal white matter involvement in neuromyelitis optica.

    Science.gov (United States)

    Hayashida, Shotaro; Masaki, Katsuhisa; Yonekawa, Tomomi; Suzuki, Satoshi O; Hiwatashi, Akio; Matsushita, Takuya; Watanabe, Mitsuru; Yamasaki, Ryo; Suenaga, Toshihiko; Iwaki, Toru; Murai, Hiroyuki; Kira, Jun-Ichi

    2017-05-01

    Studies of longitudinally extensive spinal cord lesions (LESCLs) in neuromyelitis optica (NMO) have focused on gray matter, where the relevant antigen, aquaporin-4 (AQP4), is abundant. Because spinal white matter pathology in NMO is not well characterized, we aimed to clarify spinal white matter pathology of LESCLs in NMO. We analyzed 50 spinal cord lesions from eleven autopsied NMO/NMO spectrum disorder (NMOSD) cases. We also evaluated LESCLs with three or fewer spinal cord attacks by 3-tesla MRI in 15 AQP4 antibody-positive NMO/NMOSD patients and in 15 AQP4 antibody-negative multiple sclerosis (MS) patients. Pathological analysis revealed seven cases of AQP4 loss and four predominantly demyelinating cases. Forty-four lesions from AQP4 loss cases involved significantly more frequently posterior columns (PC) and lateral columns (LC) than anterior columns (AC) (59.1%, 63.6%, and 34.1%, respectively). The posterior horn (PH), central portion (CP), and anterior horn (AH) were similarly affected (38.6%, 36.4% and 31.8%, respectively). Isolated perivascular inflammatory lesions with selective loss of astrocyte endfoot proteins, AQP4 and connexin 43, were present only in white matter and were more frequent in PC and LC than in AC (22.7%, 29.5% and 2.3%, P corr  = 0.020, and P corr  = 0.004, respectively). MRI indicated LESCLs more frequently affected PC and LC than AC in anti-AQP4 antibody-seropositive NMO/NMOSD (86.7%, 60.0% and 20.0%, P corr  = 0.005, and P corr  = 0.043, respectively) and AQP4 antibody-seronegative MS patients (86.7%, 73.3% and 33.3%, P corr  = 0.063, and P corr  = 0.043, respectively). PH, CP and AH were involved in 93.3%, 86.7% and 73.3% of seropositive patients, respectively, and in 53.3%, 60.0% and 40.0% of seronegative patients, respectively. NMO frequently and extensively affects spinal white matter in addition to central gray matter, especially in PC and LC, where isolated perivascular lesions with astrocyte endfoot

  16. Atrophy of gray and white matters in the brain during aging

    International Nuclear Information System (INIS)

    Takeda, Shumpei; Matsuzawa, Taiju; Ito, Hisao.

    1984-01-01

    We studied atrophy of gray and white matter during aging in 57 males and 44 females with no neurological disturbances using x-ray computed tomography. The ages ranged from 12 to 80 years. Brain atrophy was expressed as brain volume index: 100% x [(brain volume/cranial cavity volume) in individual subjects]/[(brain volume/cranial cavity volume) in normal subjects of 20-39 years]. Atrophy of gray and white matter volume was expressed as gray and white matter volume indices: 100% x (apparent gray or white matter volume index in individual subjects)/(apparent gray or white matter volume index in normal subjects whose brain volume index was greater than 98%), where apparent gray and white matter volume indices were expressed as 100% x [(gray or white matter volume/cranial cavity volume) in individual subjects]/[(gray or white matter volume/cranial cavity volume) in normal subjects of 20-39 years]. Both the gray and white matter volume indices changed proportionally to the brain volume index (p<0.001). As the brain atrophy advanced, the gray matter volume index decreased more than the white matter volume index (P<0.001). Decrease in the gray and white matter volume indices was statistically significant only in seventies (P<0.002 for gray matter, P<0.05 for white matter). (author)

  17. Distinct white matter abnormalities in different idiopathic generalized epilepsy syndromes.

    Science.gov (United States)

    Liu, Min; Concha, Luis; Beaulieu, Christian; Gross, Donald W

    2011-12-01

    By definition idiopathic generalized epilepsy (IGE) is not associated with structural abnormalities on conventional magnetic resonance imaging (MRI). However, recent quantitative studies suggest white and gray matter alterations in IGE. The purpose of this study was to investigate whether there are white and/or gray matter structural differences between controls and two subsets of IGE, namely juvenile myoclonic epilepsy (JME) and IGE with generalized tonic-clonic seizures only (IGE-GTC). We assessed white matter integrity and gray matter volume using diffusion tensor tractography-based analysis of fractional anisotropy and voxel-based morphometry, respectively, in 25 patients with IGE, all of whom had experienced generalized tonic-clonic convulsions. Specifically, 15 patients with JME and 10 patients with IGE-GTC were compared to two groups of similarly matched controls separately. Correlations between total lifetime generalized tonic-clonic seizures and fractional anisotropy were investigated for both groups. Tractography revealed lower fractional anisotropy in specific tracts including the crus of the fornix, body of corpus callosum, uncinate fasciculi, superior longitudinal fasciculi, anterior limb of internal capsule, and corticospinal tracts in JME with respect to controls, whereas there were no fractional anisotropy differences in IGE-GTC. No correlation was found between fractional anisotropy and total lifetime generalized tonic-clonic seizures for either JME or IGE-GTC. Although false discovery rate-corrected voxel-based morphometry (VBM) showed no gray matter volume differences between patient and control groups, spatial extent cluster-corrected VBM analysis suggested a trend of gray matter volume reduction in frontal and central regions in both patient groups, more lateral in JME and more medial in IGE-GTC. The findings support the idea that the clinical syndromes of JME and IGE-GTC have unique anatomic substrates. The fact that the primary clinical

  18. Obesity gene NEGR1 associated with white matter integrity in healthy young adults.

    Science.gov (United States)

    Dennis, Emily L; Jahanshad, Neda; Braskie, Meredith N; Warstadt, Nicholus M; Hibar, Derrek P; Kohannim, Omid; Nir, Talia M; McMahon, Katie L; de Zubicaray, Greig I; Montgomery, Grant W; Martin, Nicholas G; Toga, Arthur W; Wright, Margaret J; Thompson, Paul M

    2014-11-15

    Obesity is a crucial public health issue in developed countries, with implications for cardiovascular and brain health as we age. A number of commonly-carried genetic variants are associated with obesity. Here we aim to see whether variants in obesity-associated genes--NEGR1, FTO, MTCH2, MC4R, LRRN6C, MAP2K5, FAIM2, SEC16B, ETV5, BDNF-AS, ATXN2L, ATP2A1, KCTD15, and TNN13K--are associated with white matter microstructural properties, assessed by high angular resolution diffusion imaging (HARDI) in young healthy adults between 20 and 30 years of age from the Queensland Twin Imaging study (QTIM). We began with a multi-locus approach testing how a number of common genetic risk factors for obesity at the single nucleotide polymorphism (SNP) level may jointly influence white matter integrity throughout the brain and found a wide spread genetic effect. Risk allele rs2815752 in NEGR1 was most associated with lower white matter integrity across a substantial portion of the brain. Across the area of significance in the bilateral posterior corona radiata, each additional copy of the risk allele was associated with a 2.2% lower average FA. This is the first study to find an association between an obesity risk gene and differences in white matter integrity. As our subjects were young and healthy, our results suggest that NEGR1 has effects on brain structure independent of its effect on obesity. Copyright © 2014. Published by Elsevier Inc.

  19. The effects of white matter hyperintensities and amyloid deposition on Alzheimer dementia

    Directory of Open Access Journals (Sweden)

    Brian A. Gordon

    2015-01-01

    Conclusions: The amount of amyloid deposition and white matter damage independently predicts cognitive impairment. This suggests a diagnostic utility of qualitative white matter scales in addition to measuring amyloid levels.

  20. Loss of white matter integrity is associated with gait disorders in cerebral small vessel disease

    NARCIS (Netherlands)

    Laat, K.F. de; Tuladhar, A.M.; Norden, A.G.W. van; Norris, D.G.; Zwiers, M.P.; Leeuw, F.E. de

    2011-01-01

    Gait disturbances are common in the elderly. Cerebral small vessel disease, including white matter lesions and lacunars infarcts, is thought to disrupt white matter tracts that connect important motor regions, hence resulting in gait disturbances. Pathological studies have demonstrated abnormalities

  1. File list: His.Neu.10.AllAg.White_Matter [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  2. File list: His.Neu.20.AllAg.White_Matter [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  4. File list: His.Neu.50.AllAg.White_Matter [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  5. Exploring the multiple-hit hypothesis of preterm white matter damage using diffusion MRI

    Directory of Open Access Journals (Sweden)

    Madeleine L. Barnett

    2018-01-01

    Conclusion: This study suggests multiple perinatal risk factors have an independent association with diffuse white matter injury at term equivalent age and exposure to multiple perinatal risk factors exacerbates dMRI defined, clinically significant white matter injury. Our findings support the multiple hit hypothesis for preterm white matter injury.

  6. Occipital deep white matter hyperintensity as seen by MRI, 1

    International Nuclear Information System (INIS)

    Miyazaki, Masahito; Hashimoto, Toshiaki; Tayama, Masanobu; Kuroda, Yasuhiro

    1992-01-01

    Magnetic resonance imaging was performed in 270 patients with various neurologic complaints (1-15Y) with a 0.5 tesla superconducting imaging system using a field echo T1-weighted sequence and spin echo T2-weighted and PD-weighted sequences. Twenty-seven of them had deep white matter hyperintensity (DWMH) in the occipital lobe on T2-weighted images. The frequency of mild DWMH differed in different age groups, suggesting that mild DWMH may result from delayed myelination in the central nervous system. However, the frequency of severe DWMH, which was revealed as isointense relative to cerebrospinal fluid, did not differ in different age groups and it was significantly more common in severely retarded patients. Classification of DWMH based on the signal intensity is valuable to distinguish white matter abnormalities in the occipital lobe from delayed myelination in the same site. (author)

  7. ABCD1 dysfunction alters white matter microvascular perfusion

    DEFF Research Database (Denmark)

    Lauer, Arne; Da, Xiao; Hansen, Mikkel Bo

    2017-01-01

    Cerebral X-linked adrenoleukodystrophy is a devastating neurodegenerative disorder caused by mutations in the ABCD1 gene, which lead to a rapidly progressive cerebral inflammatory demyelination in up to 60% of affected males. Selective brain endothelial dysfunction and increased permeability...... of the blood–brain barrier suggest that white matter microvascular dysfunction contributes to the conversion to cerebral disease. Applying a vascular model to conventional dynamic susceptibility contrast magnetic reson- ance perfusion imaging, we demonstrate that lack of ABCD1 function causes increased...... capillary flow heterogeneity in asymptom- atic hemizygotes predominantly in the white matter regions and developmental stages with the highest probability for conversion to cerebral disease. In subjects with ongoing inflammatory demyelination we observed a sequence of increased capillary flow hetero...

  8. White dwarf stars as strange quark matter detectors

    Energy Technology Data Exchange (ETDEWEB)

    Benvenuto, O G [Departamento de AstronomIa y AstroFisica, Pontificia Universidad Catolica, Vicuna Mackenna 4860, Casilla 306, Santiago (Chile); Facultad de Ciencias Astronomicas y GeoFisicas, Universidad Nacional de La Plata, Paseo del Bosque S/N, B1900FWA, La Plata (Argentina)

    2005-11-01

    We show that the presence of a strange matter core inside a white dwarf (WD) star produces a drastic change in the spectrum of non-radial oscillations in the range of periods corresponding to gravity modes. The distinctive, observable signal for such a core is a very short period spacing between consecutive modes, far shorter than in the case of pulsating WDs without any compact core. (letter to the editor)

  9. Diffusion measures indicate fight exposure-related damage to cerebral white matter in boxers and mixed martial arts fighters.

    Science.gov (United States)

    Shin, W; Mahmoud, S Y; Sakaie, K; Banks, S J; Lowe, M J; Phillips, M; Modic, M T; Bernick, C

    2014-02-01

    Traumatic brain injury is common in fighting athletes such as boxers, given the frequency of blows to the head. Because DTI is sensitive to microstructural changes in white matter, this technique is often used to investigate white matter integrity in patients with traumatic brain injury. We hypothesized that previous fight exposure would predict DTI abnormalities in fighting athletes after controlling for individual variation. A total of 74 boxers and 81 mixed martial arts fighters were included in the analysis and scanned by use of DTI. Individual information and data on fight exposures, including number of fights and knockouts, were collected. A multiple hierarchical linear regression model was used in region-of-interest analysis to test the hypothesis that fight-related exposure could predict DTI values separately in boxers and mixed martial arts fighters. Age, weight, and years of education were controlled to ensure that these factors would not account for the hypothesized effects. We found that the number of knockouts among boxers predicted increased longitudinal diffusivity and transversal diffusivity in white matter and subcortical gray matter regions, including corpus callosum, isthmus cingulate, pericalcarine, precuneus, and amygdala, leading to increased mean diffusivity and decreased fractional anisotropy in the corresponding regions. The mixed martial arts fighters had increased transversal diffusivity in the posterior cingulate. The number of fights did not predict any DTI measures in either group. These findings suggest that the history of fight exposure in a fighter population can be used to predict microstructural brain damage.

  10. White matter structural connectivity and episodic memory in early childhood.

    Science.gov (United States)

    Ngo, Chi T; Alm, Kylie H; Metoki, Athanasia; Hampton, William; Riggins, Tracy; Newcombe, Nora S; Olson, Ingrid R

    2017-12-01

    Episodic memory undergoes dramatic improvement in early childhood; the reason for this is poorly understood. In adults, episodic memory relies on a distributed neural network. Key brain regions that supporting these processes include the hippocampus, portions of the parietal cortex, and portions of prefrontal cortex, each of which shows different developmental profiles. Here we asked whether developmental differences in the axonal pathways connecting these regions may account for the robust gains in episodic memory in young children. Using diffusion weighted imaging, we examined whether white matter connectivity between brain regions implicated in episodic memory differed with age, and were associated with memory performance differences in 4- and 6-year-old children. Results revealed that white matter connecting the hippocampus to the inferior parietal lobule significantly predicted children's performance on episodic memory tasks. In contrast, variation in the white matter connecting the hippocampus to the medial prefrontal cortex did not relate to memory performance. These findings suggest that structural connectivity between the hippocampus and lateral parietal regions is relevant to the development of episodic memory. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. White matter sexual dimorphism of the adult human brain

    Directory of Open Access Journals (Sweden)

    Bourisly Ali K.

    2017-05-01

    Full Text Available Sex-biased psychophysiology, behavior, brain function, and conditions are extensive, yet underlying structural brain mechanisms remain unclear. There is contradicting evidence regarding sexual dimorphism when it comes to brain structure, and there is still no consensus on whether or not there exists such a dimorphism for brain white matter. Therefore, we conducted a voxel-based morphometry (VBM analysis along with global volume analysis for white matter across sex. We analyzed 384 T1-weighted MRI brain images (192 male, 192 female to investigate any differences in white matter (WM between males and females. In the VBM analysis, we found males to have larger WM, compared to females, in occipital, temporal, insular, parietal, and frontal brain regions. In contrast, females showed only one WM region to be significantly larger than males: the right postcentral gyrus in the parietal lobe region. Although, on average, males showed larger global WM volume, we did not find any significant difference in global WM volume between males and females.

  12. An allometric scaling law between gray matter and white matter of cerebral cortex

    International Nuclear Information System (INIS)

    He Jihuan

    2006-01-01

    An allometric scaling relationship between cortical white and gray volumes is derived from a general model that describes brain's remarkable efficiency and prodigious communications between brain areas. The model assumes that (1) a cell's metabolic rate depends upon cell's surface; (2) the overall basal metabolic rates of brain areas depend upon their fractal structures; (3) differential brain areas have same basal metabolic rate at slow wave sleep. The obtained allometric exponent scaling white matter to gray matter is 1.2, which is very much close to Zhang and Sejnowski's observation data

  13. AGREEMENT BETWEEN THE WHITE MATTER CONNECTIVITY BASED ON THE TENSOR-BASED MORPHOMETRY AND THE VOLUMETRIC WHITE MATTER PARCELLATIONS BASED ON DIFFUSION TENSOR IMAGING.

    Science.gov (United States)

    Kim, Seung-Goo; Lee, Hyekyoung; Chung, Moo K; Hanson, Jamie L; Avants, Brian B; Gee, James C; Davidson, Richard J; Pollak, Seth D

    2012-01-01

    We are interested in investigating white matter connectivity using a novel computational framework that does not use diffusion tensor imaging (DTI) but only uses T1-weighted magnetic resonance imaging. The proposed method relies on correlating Jacobian determinants across different voxels based on the tensor-based morphometry (TBM) framework. In this paper, we show agreement between the TBM-based white matter connectivity and the DTI-based white matter atlas. As an application, altered white matter connectivity in a clinical population is determined.

  14. DEWS (DEep White matter hyperintensity Segmentation framework): A fully automated pipeline for detecting small deep white matter hyperintensities in migraineurs.

    Science.gov (United States)

    Park, Bo-Yong; Lee, Mi Ji; Lee, Seung-Hak; Cha, Jihoon; Chung, Chin-Sang; Kim, Sung Tae; Park, Hyunjin

    2018-01-01

    Migraineurs show an increased load of white matter hyperintensities (WMHs) and more rapid deep WMH progression. Previous methods for WMH segmentation have limited efficacy to detect small deep WMHs. We developed a new fully automated detection pipeline, DEWS (DEep White matter hyperintensity Segmentation framework), for small and superficially-located deep WMHs. A total of 148 non-elderly subjects with migraine were included in this study. The pipeline consists of three components: 1) white matter (WM) extraction, 2) WMH detection, and 3) false positive reduction. In WM extraction, we adjusted the WM mask to re-assign misclassified WMHs back to WM using many sequential low-level image processing steps. In WMH detection, the potential WMH clusters were detected using an intensity based threshold and region growing approach. For false positive reduction, the detected WMH clusters were classified into final WMHs and non-WMHs using the random forest (RF) classifier. Size, texture, and multi-scale deep features were used to train the RF classifier. DEWS successfully detected small deep WMHs with a high positive predictive value (PPV) of 0.98 and true positive rate (TPR) of 0.70 in the training and test sets. Similar performance of PPV (0.96) and TPR (0.68) was attained in the validation set. DEWS showed a superior performance in comparison with other methods. Our proposed pipeline is freely available online to help the research community in quantifying deep WMHs in non-elderly adults.

  15. Response inhibition is associated with white matter microstructure in children

    DEFF Research Database (Denmark)

    Madsen, Kathrine Skak; Baaré, William; Vestergaard, Martin

    2010-01-01

    Cognitive control of thoughts, actions and emotions is important for normal behaviour and the development of such control continues throughout childhood and adolescence. Several lines of evidence suggest that response inhibition is primarily mediated by a right-lateralized network involving...... to the prediction of performance variability. Observed associations may be related to variation in phase of maturation, to activity-dependent alterations in the network subserving response inhibition, or to stable individual differences in underlying neural system connectivity. (C) 2009 Elsevier Ltd. All rights...

  16. Response Inhibition Is Associated with White Matter Microstructure in Children

    Science.gov (United States)

    Madsen, Kathrine Skak; Baare, William F. C.; Vestergaard, Martin; Skimminge, Arnold; Ejersbo, Lisser Rye; Ramsoy, Thomas Z.; Gerlach, Christian; Akeson, Per; Paulson, Olaf B.; Jernigan, Terry L.

    2010-01-01

    Cognitive control of thoughts, actions and emotions is important for normal behaviour and the development of such control continues throughout childhood and adolescence. Several lines of evidence suggest that response inhibition is primarily mediated by a right-lateralized network involving inferior frontal gyrus (IFG), presupplementary motor…

  17. Perilesional and contralateral white matter evolution and integrity in patients with periventricular nodular heterotopia and epilepsy: a longitudinal diffusion tensor imaging study.

    Science.gov (United States)

    Liu, W; Yan, B; An, D; Niu, R; Tang, Y; Tong, X; Gong, Q; Zhou, D

    2017-12-01

    This study aimed to assess the evolution of perinodular and contralateral white matter abnormalities in patients with periventricular nodular heterotopia (PNH) and epilepsy. Diffusion tensor imaging (DTI) (64 directions) and 3 T structural magnetic resonance imaging were performed in 29 PNH patients (mean age 27.3 years), and 16 patients underwent a second scan (average time between the two scans 1.1 years). Fractional anisotropy and mean diffusivity were measured within the perilesional and contralateral white matter. Longitudinal analysis showed that white matter located 10 mm from the focal nodule displayed characteristics intermediate to tissue 5 mm away, and normal-appearing white matter (NAWM) also established evolution profiles of perinodular white matter in different cortical lobes. Compared to 29 age- and sex-matched healthy controls, significant decreased fractional anisotropy and elevated mean diffusivity values were observed in regions 5 and 10 mm from nodules (P < 0.01), whilst DTI metrics of the remaining NAWM did not differ significantly from controls. Additionally, normal DTI metrics were shown in the contralateral region in patients with unilateral PNH. Periventricular nodular heterotopia is associated with microstructural abnormalities within the perilesional white matter and the extent decreases with increasing distance from the nodule. In the homologous contralateral region, white matter diffusion metrics were unchanged in unilateral PNH. These findings have clinical implications with respect to the medical and surgical interventions of PNH-related epilepsy. © 2017 EAN.

  18. Metric to quantify white matter damage on brain magnetic resonance images

    International Nuclear Information System (INIS)

    Valdes Hernandez, Maria del C.; Munoz Maniega, Susana; Anblagan, Devasuda; Bastin, Mark E.; Wardlaw, Joanna M.; Chappell, Francesca M.; Morris, Zoe; Sakka, Eleni; Dickie, David Alexander; Royle, Natalie A.; Armitage, Paul A.; Deary, Ian J.

    2017-01-01

    Quantitative assessment of white matter hyperintensities (WMH) on structural Magnetic Resonance Imaging (MRI) is challenging. It is important to harmonise results from different software tools considering not only the volume but also the signal intensity. Here we propose and evaluate a metric of white matter (WM) damage that addresses this need. We obtained WMH and normal-appearing white matter (NAWM) volumes from brain structural MRI from community dwelling older individuals and stroke patients enrolled in three different studies, using two automatic methods followed by manual editing by two to four observers blind to each other. We calculated the average intensity values on brain structural fluid-attenuation inversion recovery (FLAIR) MRI for the NAWM and WMH. The white matter damage metric is calculated as the proportion of WMH in brain tissue weighted by the relative image contrast of the WMH-to-NAWM. The new metric was evaluated using tissue microstructure parameters and visual ratings of small vessel disease burden and WMH: Fazekas score for WMH burden and Prins scale for WMH change. The correlation between the WM damage metric and the visual rating scores (Spearman ρ > =0.74, p =0.72, p < 0.0001). The repeatability of the WM damage metric was better than WM volume (average median difference between measurements 3.26% (IQR 2.76%) and 5.88% (IQR 5.32%) respectively). The follow-up WM damage was highly related to total Prins score even when adjusted for baseline WM damage (ANCOVA, p < 0.0001), which was not always the case for WMH volume, as total Prins was highly associated with the change in the intense WMH volume (p = 0.0079, increase of 4.42 ml per unit change in total Prins, 95%CI [1.17 7.67]), but not with the change in less-intense, subtle WMH, which determined the volumetric change. The new metric is practical and simple to calculate. It is robust to variations in image processing methods and scanning protocols, and sensitive to subtle and severe white

  19. Metric to quantify white matter damage on brain magnetic resonance images

    Energy Technology Data Exchange (ETDEWEB)

    Valdes Hernandez, Maria del C.; Munoz Maniega, Susana; Anblagan, Devasuda; Bastin, Mark E.; Wardlaw, Joanna M. [University of Edinburgh, Department of Neuroimaging Sciences, Centre for Clinical Brain Sciences, Edinburgh (United Kingdom); University of Edinburgh, Centre for Cognitive Ageing and Cognitive Epidemiology, Edinburgh (United Kingdom); UK Dementia Research Institute, Edinburgh Dementia Research Centre, London (United Kingdom); Chappell, Francesca M.; Morris, Zoe; Sakka, Eleni [University of Edinburgh, Department of Neuroimaging Sciences, Centre for Clinical Brain Sciences, Edinburgh (United Kingdom); UK Dementia Research Institute, Edinburgh Dementia Research Centre, London (United Kingdom); Dickie, David Alexander; Royle, Natalie A. [University of Edinburgh, Department of Neuroimaging Sciences, Centre for Clinical Brain Sciences, Edinburgh (United Kingdom); University of Edinburgh, Centre for Cognitive Ageing and Cognitive Epidemiology, Edinburgh (United Kingdom); Armitage, Paul A. [University of Sheffield, Department of Cardiovascular Sciences, Sheffield (United Kingdom); Deary, Ian J. [University of Edinburgh, Centre for Cognitive Ageing and Cognitive Epidemiology, Edinburgh (United Kingdom); University of Edinburgh, Department of Psychology, Edinburgh (United Kingdom)

    2017-10-15

    Quantitative assessment of white matter hyperintensities (WMH) on structural Magnetic Resonance Imaging (MRI) is challenging. It is important to harmonise results from different software tools considering not only the volume but also the signal intensity. Here we propose and evaluate a metric of white matter (WM) damage that addresses this need. We obtained WMH and normal-appearing white matter (NAWM) volumes from brain structural MRI from community dwelling older individuals and stroke patients enrolled in three different studies, using two automatic methods followed by manual editing by two to four observers blind to each other. We calculated the average intensity values on brain structural fluid-attenuation inversion recovery (FLAIR) MRI for the NAWM and WMH. The white matter damage metric is calculated as the proportion of WMH in brain tissue weighted by the relative image contrast of the WMH-to-NAWM. The new metric was evaluated using tissue microstructure parameters and visual ratings of small vessel disease burden and WMH: Fazekas score for WMH burden and Prins scale for WMH change. The correlation between the WM damage metric and the visual rating scores (Spearman ρ > =0.74, p < 0.0001) was slightly stronger than between the latter and WMH volumes (Spearman ρ > =0.72, p < 0.0001). The repeatability of the WM damage metric was better than WM volume (average median difference between measurements 3.26% (IQR 2.76%) and 5.88% (IQR 5.32%) respectively). The follow-up WM damage was highly related to total Prins score even when adjusted for baseline WM damage (ANCOVA, p < 0.0001), which was not always the case for WMH volume, as total Prins was highly associated with the change in the intense WMH volume (p = 0.0079, increase of 4.42 ml per unit change in total Prins, 95%CI [1.17 7.67]), but not with the change in less-intense, subtle WMH, which determined the volumetric change. The new metric is practical and simple to calculate. It is robust to variations in

  20. QCD matter in white dwarfs and supernova collapse

    International Nuclear Information System (INIS)

    Mathews, Grant J.; Meixner, M.; Lan, N.Q.; Suh, I.-S.

    2010-01-01

    The search for astrophysical evidence for a transition to QCD matter is an important goal. Although much effort has gone into searching for neutron star candidates, here we describe the exploration of two other possible signatures. One is the search for strange dwarfs. Masses and radii for a large number of white dwarfs have been deduced from a combination of proper motion studies, Hipparcos parallax distances, effective temperatures, and binary or spectroscopic masses. Some stars appear to have radii which are significantly smaller than that expected for a standard electron-degenerate white-dwarf equation of state. We argue that there is marginal evidence for bimodality in the radius distribution. We show that the data exhibit several features consistent with the expected mass-radius relation of strange dwarfs. We identify eight nearby white dwarfs that are possible candidates for strange matter cores and suggest observational tests of this hypothesis. We also review the current status of core-collapse supernova research, and in particular, the effects on the explosion of a QCD phase transition in the proto-neutron-star core. We describe how a first order transition could enhance the explosion and lead to observable effects in the emergent neutrino light curve. (author)

  1. Automated detection of Lupus white matter lesions in MRI

    Directory of Open Access Journals (Sweden)

    Eloy Roura Perez

    2016-08-01

    Full Text Available Brain magnetic resonance imaging provides detailed information which can be used to detect and segment white matter lesions (WML. In this work we propose an approach to automatically segment WML in Lupus patients by using T1w and fluid-attenuated inversion recovery (FLAIR images. Lupus WML appear as small focal abnormal tissue observed as hyperintensities in the FLAIR images. The quantification of these WML is a key factor for the stratification of lupus patients and therefore both lesion detection and segmentation play an important role. In our approach, the T1w image is first used to classify the three main tissues of the brain, white matter (WM, gray matter (GM and cerebrospinal fluid (CSF, while the FLAIR image is then used to detect focal WML as outliers of its GM intensity distribution. A set of post-processing steps based on lesion size, tissue neighborhood, and location are used to refine the lesion candidates. The proposal is evaluated on 20 patients, presenting qualitative and quantitative results in terms of precision and sensitivity of lesion detection (True Positive Rate (62% and Positive Prediction Value (80% respectively as well as segmentation accuracy (Dice Similarity Coefficient (72%. Obtained results illustrate the validity of the approach to automatically detect and segment lupus lesions. Besides, our approach is publicly available as a SPM8/12 toolbox extension with a simple parameter configuration.

  2. White-matter tract abnormalities and antisocial behavior: A systematic review of diffusion tensor imaging studies across development

    Directory of Open Access Journals (Sweden)

    Rebecca Waller

    2017-01-01

    Full Text Available Antisocial behavior (AB, including aggression, violence, and theft, is thought be underpinned by abnormal functioning in networks of the brain critical to emotion processing, behavioral control, and reward-related learning. To better understand the abnormal functioning of these networks, research has begun to investigate the structural connections between brain regions implicated in AB using diffusion tensor imaging (DTI, which assesses white-matter tract microstructure. This systematic review integrates findings from 22 studies that examined the relationship between white-matter microstructure and AB across development. In contrast to a prior hypothesis that AB is associated with greater diffusivity specifically in the uncinate fasciculus, findings suggest that adult AB is associated with greater diffusivity across a range of white-matter tracts, including the uncinate fasciculus, inferior fronto-occipital fasciculus, cingulum, corticospinal tract, thalamic radiations, and corpus callosum. The pattern of findings among youth studies was inconclusive with both higher and lower diffusivity found across association, commissural, and projection and thalamic tracts.

  3. Comprehensive Investigation of White Matter Tracts in Professional Chess Players and Relation to Expertise: Region of Interest and DMRI Connectometry.

    Science.gov (United States)

    Mayeli, Mahsa; Rahmani, Farzaneh; Aarabi, Mohammad Hadi

    2018-01-01

    Purpose: Expertise is the product of training. Few studies have used functional connectivity or conventional diffusometric methods to identify neural underpinnings of chess expertise. Diffusometric variables of white matter might reflect these adaptive changes, along with changes in structural connectivity, which is a sensitive measure of microstructural changes. Method: Diffusometric variables of 29 professional chess players and 29 age-sex matched controls were extracted for white matter regions based on John Hopkin's Mori white matter atlas and partially correlated against professional training time and level of chess proficiency. Diffusion MRI connectometry was implemented to identify changes in structural connectivity in professional players compared to novices. Result: Compared to novices, higher planar anisotropy (CP) was observed in inferior longitudinal fasciculus (ILF), superior longitudinal fasciculus (SLF) and cingulate gyrus, in professional chess players, which correlated with higher RPM score in this group. Higher fractional anisotropy (FA) was observed in ILF, uncinate fasciculus (UF) and hippocampus and correlated with better scores in Raven's progressive matrices (RPM) score and longer duration of chess training in professional players. Consistently, radial diffusivity in bilateral IFOF, bilateral ILF and bilateral SLF was inversely correlated with level of training in professional players. DMRI connectometry analysis identified increased connectivity in bilateral UF, bilateral IFOF, bilateral cingulum, and corpus callosum in chess player's compared to controls. Conclusion: Structural connectivity of major associational subcortical white matter fibers are increased in professional chess players. FA and CP of ILF, SLF and UF directly correlates with duration of professional training and RPM score, in professional chess players.

  4. White Matter Injury and General Movements in High-Risk Preterm Infants.

    Science.gov (United States)

    Peyton, C; Yang, E; Msall, M E; Adde, L; Støen, R; Fjørtoft, T; Bos, A F; Einspieler, C; Zhou, Y; Schreiber, M D; Marks, J D; Drobyshevsky, A

    2017-01-01

    Very preterm infants (birth weight, cognitive and motor impairment, including cerebral palsy. These adverse neurodevelopmental outcomes are associated with white matter abnormalities on MR imaging at term-equivalent age. Cerebral palsy has been predicted by analysis of spontaneous movements in the infant termed "General Movement Assessment." The goal of this study was to determine the utility of General Movement Assessment in predicting adverse cognitive, language, and motor outcomes in very preterm infants and to identify brain imaging markers associated with both adverse outcomes and aberrant general movements. In this prospective study of 47 preterm infants of 24-30 weeks' gestation, brain MR imaging was performed at term-equivalent age. Infants underwent T1- and T2-weighted imaging for volumetric analysis and DTI. General movements were assessed at 10-15 weeks' postterm age, and neurodevelopmental outcomes were evaluated at 2 years by using the Bayley Scales of Infant and Toddler Development III. Nine infants had aberrant general movements and were more likely to have adverse neurodevelopmental outcomes, compared with infants with normal movements. In infants with aberrant movements, Tract-Based Spatial Statistics analysis identified significantly lower fractional anisotropy in widespread white matter tracts, including the corpus callosum, inferior longitudinal and fronto-occipital fasciculi, internal capsule, and optic radiation. The subset of infants having both aberrant movements and abnormal neurodevelopmental outcomes in cognitive, language, and motor skills had significantly lower fractional anisotropy in specific brain regions. Aberrant general movements at 10-15 weeks' postterm are associated with adverse neurodevelopmental outcomes and specific white matter microstructure abnormalities for cognitive, language, and motor delays. © 2017 by American Journal of Neuroradiology.

  5. White dwarf stars: cosmic chronometers and dark matter probes

    Science.gov (United States)

    Salaris, Maurizio; Cassisi, Santi

    2018-04-01

    White dwarfs (WD) are the endpoint of the evolution of the large majority of stars formed in our galaxy. In the last two decades observations and theory have improved to a level that makes it possible to employ WD for determining ages of the stellar populations in the disk of the Milky Way and in the nearest star clusters, and constrain the existence and properties of dark matter (DM) candidates. This review is centred on WD models, age-dating, and DM identification methods, recent results and future developments of the field.

  6. White matter lesions in psychiatric patients: a retrospective MRI study

    International Nuclear Information System (INIS)

    Becker, T.; Teichmann, E.; Hofmann, E.; Schmidtke, A.; Warmuth-Metz, M.; Nadjmi, M.

    1992-01-01

    T2-weighted MRI scans of psychiatric patients with at least one white matter lesion (WML) were compared to 83 non-psychiatric controls with respect to WML number and distribution. MANOVA resulted in significant effects for sex, age and patient group with respect to WML number. In the psychiatric patients, infratentorial WML prevailed in organic psychoses. WML number was positively correlated with age with the exception of right temporal lobe WML. Based on WML spatial distribution, four patient clusters were found. Clusters with widely distributed WML comprised older patients with late onset of illness; right frontal and temporal WML were associated with mania, euphoria and unstable mood. (orig.)

  7. Memory binding and white matter integrity in familial Alzheimer's disease.

    Science.gov (United States)

    Parra, Mario A; Saarimäki, Heini; Bastin, Mark E; Londoño, Ana C; Pettit, Lewis; Lopera, Francisco; Della Sala, Sergio; Abrahams, Sharon

    2015-05-01

    Binding information in short-term and long-term memory are functions sensitive to Alzheimer's disease. They have been found to be affected in patients who meet criteria for familial Alzheimer's disease due to the mutation E280A of the PSEN1 gene. However, only short-term memory binding has been found to be affected in asymptomatic carriers of this mutation. The neural correlates of this dissociation are poorly understood. The present study used diffusion tensor magnetic resonance imaging to investigate whether the integrity of white matter structures could offer an account. A sample of 19 patients with familial Alzheimer's disease, 18 asymptomatic carriers and 21 non-carrier controls underwent diffusion tensor magnetic resonance imaging, neuropsychological and memory binding assessment. The short-term memory binding task required participants to detect changes across two consecutive screens displaying arrays of shapes, colours, or shape-colour bindings. The long-term memory binding task was a Paired Associates Learning Test. Performance on these tasks were entered into regression models. Relative to controls, patients with familial Alzheimer's disease performed poorly on both memory binding tasks. Asymptomatic carriers differed from controls only in the short-term memory binding task. White matter integrity explained poor memory binding performance only in patients with familial Alzheimer's disease. White matter water diffusion metrics from the frontal lobe accounted for poor performance on both memory binding tasks. Dissociations were found in the genu of corpus callosum which accounted for short-term memory binding impairments and in the hippocampal part of cingulum bundle which accounted for long-term memory binding deficits. The results indicate that white matter structures in the frontal and temporal lobes are vulnerable to the early stages of familial Alzheimer's disease and their damage is associated with impairments in two memory binding functions known to

  8. Gray- and White-Matter Anatomy of Absolute Pitch Possessors

    DEFF Research Database (Denmark)

    Dohn, Anders; Garza-Villarreal, Eduardo A.; Chakravarty, Mallar

    2015-01-01

    structural differences in brains of musicians with and without AP, by means of whole brain vertex- wise cortical thickness analysis and tract-based spatial statistics (TBSS) analysis. AP possessors (APs) displayed increased cortical thickness in a number of areas including the left superior temporal gyrus......, the left inferior frontal gyrus, and the right supramarginal gyrus. Furthermore, we found increased fractional anisotropy in APs within the path of the inferior fronto-occipital fasciculus, the uncinate fasciculus and the inferior longitudinal fasciculus. The findings in gray matter support previous...... studies indicating an increased left lateralized posterior superior temporal gyrus in APs, yet they differ from previous findings of thinner cortex for a number of areas in APs. Finally, we found a correlation between the white matter cluster and the right parahippocampal gyrus. This is a novel finding...

  9. White matter abnormalities and their impact on attentional performance in adult attention-deficit/hyperactivity disorder.

    Science.gov (United States)

    Konrad, Andreas; Dielentheis, Thomas F; El Masri, Dschamil; Dellani, Paulo R; Stoeter, Peter; Vucurevic, Goran; Winterer, Georg

    2012-06-01

    Inattention is the most important behavioral feature of adult patients with attention-deficit/hyperactivity disorder (ADHD). Neuroimaging studies in ADHD have demonstrated abnormalities primarily in the frontostriatal circuitry and were mostly conducted in children. We investigated white matter (WM) integrity in adult ADHD patients and the correlation of WM microstructure and neuropsychological parameters in 37 (21 men) never-medicated adult ADHD patients and 34 age- and gender-matched healthy controls. All subjects underwent clinical interviews, rating scales, and neuropsychological tests of attentional performance. Diffusion tensor imaging (DTI) was acquired, and 12 WM regions-of-interest (ROIs) within the attentional network were chosen. Group differences of mean fractional anisotropy (FA) and mean diffusivity (MD) values were calculated for each ROI, and patients' DTI measures were then correlated with measures of attentional performance. FA values in ADHD patients were significantly reduced in the left inferior longitudinal fasciculus (ILF), while MD values were significantly increased in ADHD patients in the frontal portion of the left frontooccipital fasciculus (IFO). In ADHD patients, MD values were negatively correlated with attentional performance in the left ILF. Our findings provide further support for disturbed frontostriatal structural connectivity and also point to an involvement of the left temporal white matter with an impact on attentional performance.

  10. White matter and reading deficits after pediatric traumatic brain injury: A diffusion tensor imaging study

    Directory of Open Access Journals (Sweden)

    Chad Parker Johnson

    2015-01-01

    Full Text Available Pediatric traumatic brain injury often results in significant long-term deficits in mastery of reading ability. This study aimed to identify white matter pathways that, when damaged, predicted reading deficits in children. Based on the dual-route model of word reading, we predicted that integrity of the inferior fronto-occipital fasciculus would be related to performance in sight word identification while integrity of the superior longitudinal fasciculus would be related to performance in phonemic decoding. Reading fluency and comprehension were hypothesized to relate to the superior longitudinal fasciculus, inferior fronto-occipital fasciculus, and cingulum bundle. The connectivity of white matter pathways was used to predict reading deficits in children aged 6 to 16 years with traumatic brain injury (n = 29 and those with orthopedic injury (n = 27 using tract-based spatial statistics. Results showed that children with traumatic brain injury and reduced microstructural integrity of the superior longitudinal fasciculus demonstrated reduced word-reading ability on sight word and phonemic decoding tasks. Additionally, children with traumatic brain injury and microstructural changes involving the cingulum bundle demonstrated reduced reading fluency. Results support the association of a dorsal pathway via the superior longitudinal fasciculus with both sight word reading and phonemic decoding. No association was identified between the inferior fronto-occipital fasciculus and sight word reading or phonemic decoding. Reading fluency was associated with the integrity of the cingulum bundle. These findings support dissociable pathways predicting word reading and fluency using Diffusion Tensor Imaging and provide additional information for developing models of acquired reading deficits by specifying areas of brain damage which may predict reading deficits following recovery from the acute phase of TBI.

  11. Moderate Physical Activity Mediates the Association between White Matter Lesion Volume and Memory Recall in Breast Cancer Survivors.

    Directory of Open Access Journals (Sweden)

    Gillian E Cooke

    Full Text Available Increased survival rates among breast cancer patients have drawn significant attention to consequences of both the presence of cancer, and the subsequent treatment-related impact on the brain. The incidence of breast cancer and the effects of treatment often result in alterations in the microstructure of white matter and impaired cognitive functioning. However, physical activity is proving to be a successful modifiable lifestyle factor in many studies that could prove beneficial to breast cancer survivors. This study investigates the link between white matter lesion volume, moderate physical activity, and cognition in breast cancer survivors following treatment compared to non-cancer age-matched controls. Results revealed that brain structure significantly predicted cognitive function via mediation of physical activity in breast cancer survivors. Overall, the study provided preliminary evidence suggesting moderate physical activity may help reduce the treatment related risks associated with breast cancer, including changes to WM integrity and cognitive impairment.

  12. Disrupted white matter structure underlies cognitive deficit in hypertensive patients

    International Nuclear Information System (INIS)

    Li, Xin; Ma, Chao; Zhang, Junying; Chen, Yaojing; Zhang, Zhanjun; Sun, Xuan; Chen, Kewei

    2016-01-01

    Hypertension is considered a risk factor of cognitive impairments and could result in white matter changes. Current studies on hypertension-related white matter (WM) changes focus only on regional changes, and the information about global changes in WM structure network is limited. We assessed the cognitive function in 39 hypertensive patients and 37 healthy controls with a battery of neuropsychological tests. The WM structural networks were constructed by utilizing diffusion tensor tractography and calculated topological properties of the networks using a graph theoretical method. The direct and indirect correlations among cognitive impairments, brain WM network disruptions and hypertension were analyzed with structural equation modelling (SEM). Hypertensive patients showed deficits in executive function, memory and attention compared with controls. An aberrant connectivity of WM networks was found in the hypertensive patients (P Eglob = 0.005, P Lp = 0.005), especially in the frontal and parietal regions. Importantly, SEM analysis showed that the decline of executive function resulted from aberrant WM networks in hypertensive patients (p = 0.3788, CFI = 0.99). These results suggest that the cognitive decline in hypertensive patients was due to frontal and parietal WM disconnections. Our findings highlight the importance of brain protection in hypertension patients. (orig.)

  13. Malnutrition and cerebral white matter lesions in dialysis patients

    International Nuclear Information System (INIS)

    Mukai, Masanori; Mukai, Kazumitsu; Ichikawa, Hiroo; Sanada, Daisuke; Shibata, Takanori; Kawamura, Mitsuru; Akizawa, Tadao; Wakasa, Mikio

    2008-01-01

    The objective of this study was to examine the association between nutritional status and the severity of cerebral white matter lesions (WMLs) in dialysis patients. Subjects consisted of 28 patients with end-stage renal failure who underwent regular hemodialysis in the affiliated hospitals of Showa University Hospital. All subjects underwent brain MRI and various clinical and laboratory tests. All subjects were divided into three groups based on the following criteria. Group I was defined as having 0 or 1 of the 4 findings of malnutrition (body mass index 2 , total lymphocyte counts 3 , serum albumin concentrations <3.5 g/dL, normalized protein catabolic rate <0.9 g/kg/day). Group II was defined as having 2 of these 4 findings, and group III was defined as having 3 or all of these 4 findings. WMLs detected on T2-weightd MRI were rated using the semiquantitative method yielding two continuous variables (perivascular hyperintensity (PVH) scores, deep subcortical white matter hyperintensity (DSWMH) scores). PVH and DSWMH scores were significantly higher in patients in groups III and II compared to that of those in group I. Multiple regression analysis demonstrated that the four findings of malnourishment described above had significant impact on PVH and DSWMH scores. These findings suggest that nutritional status (especially malnutrition) in dialysis patients may be involved in the severity of WMLs. (author)

  14. Effects of bilingualism on white matter integrity in older adults.

    Science.gov (United States)

    Anderson, John A E; Grundy, John G; De Frutos, Jaisalmer; Barker, Ryan M; Grady, Cheryl; Bialystok, Ellen

    2018-02-15

    Bilingualism can delay the onset of dementia symptoms and has thus been characterized as a mechanism for cognitive or brain reserve, although the origin of this reserve is unknown. Studies with young adults generally show that bilingualism is associated with a strengthening of white matter, but there is conflicting evidence for how bilingualism affects white matter in older age. Given that bilingualism has been shown to help stave off the symptoms of dementia by up to four years, it is crucial that we clarify the mechanism underlying this reserve. The current study uses diffusion tensor imaging (DTI) to compare monolinguals and bilinguals while carefully controlling for potential confounds (e.g., I.Q., MMSE, and demographic variables). We show that group differences in Fractional Anisotropy (FA) and Radial Diffusivity (RD) arise from multivariable interactions not adequately controlled for by sequential bivariate testing. After matching and statistically controlling for confounds, bilinguals still had greater axial diffusivity (AD) in the left superior longitudinal fasciculus than monolingual peers, supporting a neural reserve account for healthy older bilinguals. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Reduced anterior internal capsule white matter integrity in primary insomnia.

    Science.gov (United States)

    Spiegelhalder, Kai; Regen, Wolfram; Prem, Martin; Baglioni, Chiara; Nissen, Christoph; Feige, Bernd; Schnell, Susanne; Kiselev, Valerij G; Hennig, Jürgen; Riemann, Dieter

    2014-07-01

    Chronic insomnia is one of the most prevalent central nervous system diseases, however, its neurobiology is poorly understood. Up to now, nothing is known about the integrity of white matter tracts in insomnia patients. In this study, diffusion tensor imaging (DTI) was used in a well-characterized sample of primary insomnia (PI) patients and good sleeper controls to fill this void. Voxelwise between-group comparisons of fractional anisotropy (FA) were performed in 24 PI patients (10 males; 14 females; 42.7 ± 14.5 years) and 35 healthy good sleepers (15 males; 20 females; 40.1 ± 9.1 years) with age and sex as covariates. PI patients showed reduced FA values within the right anterior internal capsule and a trend for reduced FA values in the left anterior internal capsule. The results suggest that insomnia is associated with a reduced integrity of white matter tracts in the anterior internal capsule indicating that disturbed fronto-subcortical connectivity may be a cause or consequence of the disorder.

  16. Abnormal white matter structural connectivity in treatment-naïve young adults with borderline personality disorder.

    Science.gov (United States)

    Gan, J; Yi, J; Zhong, M; Cao, X; Jin, X; Liu, W; Zhu, X

    2016-12-01

    The pathogenesis of borderline personality disorder (BPD) is not well understood. We examined the microstructure of white matter in patients with BPD. Treatment-naïve young adult with BPD (N = 30) and young-adult healthy controls (HCs; N = 31) were subjected diffusion tensor imaging (DTI). Microstructural parameters were analyzed via tract-based spatial statistics (TBSS) and post hoc tractography. TBSS analysis revealed that, relative to the HC group, the BPD group had significantly lower fractional anisotropy (FA) values in the genu and body of the corpus callosum (CC), right superior corona radiate, right anterior corona radiate, as well as higher radial diffusivity (RD) in the left anterior thalamic radiation. Tractography showed that FA values of fiber bundles passing through the fornix were significantly reduced in BPD group relative to HCs. No significant correlations were observed between clinical symptom and DTI indices in BPD group (FDR corrected). Focal microstructural alterations were found in BPD group, mainly in the limbic system and CC. The present findings support the fronto-limbic disconnectivity hypothesis and suggest that abnormal maturation of white matter structures may play an important role in mechanism of BPD. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Deviant white matter structure in adults with attention-deficit/hyperactivity disorder points to aberrant myelination and affects neuropsychological performance.

    Science.gov (United States)

    Onnink, A Marten H; Zwiers, Marcel P; Hoogman, Martine; Mostert, Jeanette C; Dammers, Janneke; Kan, Cornelis C; Vasquez, Alejandro Arias; Schene, Aart H; Buitelaar, Jan; Franke, Barbara

    2015-12-03

    Attention-deficit/hyperactivity disorder (ADHD) in childhood is characterized by gray and white matter abnormalities in several brain areas. Considerably less is known about white matter microstructure in adults with ADHD and its relation with clinical symptoms and cognitive performance. In 107 adult ADHD patients and 109 gender-, age- and IQ-matched controls, we used diffusion tensor imaging (DTI) with tract-based spatial statistics (TBSS) to investigate whole-skeleton changes of fractional anisotropy (FA) and mean, axial, and radial diffusivity (MD, AD, RD). Additionally, we studied the relation of FA and MD values with symptom severity and cognitive performance on tasks measuring working memory, attention, inhibition, and delay discounting. In comparison to controls, participants with ADHD showed reduced FA in corpus callosum, bilateral corona radiata, and thalamic radiation. Higher MD and RD were found in overlapping and even more widespread areas in both hemispheres, also encompassing internal and external capsule, sagittal stratum, fornix, and superior lateral fasciculus. Values of FA and MD were not associated with symptom severity. However, within some white matter clusters that distinguished patients from controls, worse inhibition performance was associated with reduced FA and more impulsive decision making was associated with increased MD. This study shows widespread differences in white matter integrity between adults with persistent ADHD and healthy individuals. Changes in RD suggest aberrant myelination as a pathophysiological factor in persistent ADHD. The microstructural differences in adult ADHD may contribute to poor inhibition and greater impulsivity but appear to be independent of disease severity. Copyright © 2015. Published by Elsevier Inc.

  18. Segmentation of brain parenchymal regions into gray matter and white matter with Alzheimer's disease

    International Nuclear Information System (INIS)

    Tokunaga, Chiaki; Yoshiura, Takashi; Yamashita, Yasuo; Magome, Taiki; Honda, Hiroshi; Arimura, Hidetaka; Toyofuku, Fukai; Ohki, Masafumi

    2010-01-01

    It is very difficult and time consuming for neuroradiologists to estimate the degree of cerebral atrophy based on the volume of cortical regions etc. Our purpose of this study was to develop an automated segmentation of the brain parenchyma into gray and white matter regions with Alzheimer's disease (AD) in three-dimensional (3D) T1-weighted MR images. Our proposed method consisted of extraction of a brain parenchymal region based on a brain model matching and segmentation of the brain parenchyma into gray and white matter regions based on a fuzzy c-means (FCM) algorithm. We applied our proposed method to MR images of the whole brains obtained from 9 cases, including 4 clinically AD cases and 5 control cases. The mean volume percentage of a cortical region (41.7%) to a brain parenchymal region in AD patients was smaller than that (45.2%) in the control subjects (p=0.000462). (author)

  19. Whole-brain voxel-based morphometry of white matter in mild cognitive impairment

    International Nuclear Information System (INIS)

    Wang Zhiqun; Guo Xiaojuan; Qi Zhigang; Yao Li; Li Kuncheng

    2010-01-01

    Purpose: The purpose of this study was to analyze whole-brain white matter changes in mild cognitive impairment (MCI). Materials and methods: We studied 14 patients with MCI and 14 age- and sex-matched healthy control subjects using voxel-based morphometry (VBM) on T1-weighted 3D datasets. The data were collected on a 3T MR system and analyzed by SPM2 to generate white matter volume maps. Results: Voxel-based morphometry revealed diffusively reduced white matter in MCI prominently including the bilateral temporal gyrus, the right anterior cingulate, the bilateral superior and medial frontal gyrus and right parietal angular gyrus. White matter reduction was more prominent in anterior regions than that in posterior regions. Conclusion: Whole-brain white matter reduction in MCI patients detected with VBM has special distribution which is in line with the white matter pathology of MCI.

  20. Whole-brain voxel-based morphometry of white matter in mild cognitive impairment

    Energy Technology Data Exchange (ETDEWEB)

    Wang Zhiqun [Department of Radiology, Xuanwu Hospital of Capital Medical University, 100053, Beijing (China); Guo Xiaojuan [College of Information Science and Technology, Beijing Normal University, 100875, Beijing (China); National Key Laboratory for Cognitive Neuroscience and Learning, Beijing Normal University, 100875, Beijing (China); Qi Zhigang [Department of Radiology, Xuanwu Hospital of Capital Medical University, 100053, Beijing (China); Yao Li [College of Information Science and Technology, Beijing Normal University, 100875, Beijing (China); National Key Laboratory for Cognitive Neuroscience and Learning, Beijing Normal University, 100875, Beijing (China); Li Kuncheng, E-mail: likuncheng@xwh.ccmu.edu.c [Department of Radiology, Xuanwu Hospital of Capital Medical University, 100053, Beijing (China)

    2010-08-15

    Purpose: The purpose of this study was to analyze whole-brain white matter changes in mild cognitive impairment (MCI). Materials and methods: We studied 14 patients with MCI and 14 age- and sex-matched healthy control subjects using voxel-based morphometry (VBM) on T1-weighted 3D datasets. The data were collected on a 3T MR system and analyzed by SPM2 to generate white matter volume maps. Results: Voxel-based morphometry revealed diffusively reduced white matter in MCI prominently including the bilateral temporal gyrus, the right anterior cingulate, the bilateral superior and medial frontal gyrus and right parietal angular gyrus. White matter reduction was more prominent in anterior regions than that in posterior regions. Conclusion: Whole-brain white matter reduction in MCI patients detected with VBM has special distribution which is in line with the white matter pathology of MCI.

  1. A Voxel-Based Diffusion Tensor Imaging Study of White Matter in Bipolar Disorder

    OpenAIRE

    Mahon, Katie; Wu, Jinghui; Malhotra, Anil K.; Burdick, Katherine E.; DeRosse, Pamela; Ardekani, Babak A.; Szeszko, Philip R.

    2009-01-01

    There is evidence from post-mortem and magnetic resonance imaging studies that hyperintensities, oligodendrioglial abnormalities and gross white matter volumetric alterations play a role in the pathophysiology of bipolar disorder. There is also functional imaging evidence for a defect in frontal cortico-subcortical pathways in bipolar disorder, but the white matter comprising these pathways has not been well-investigated. Few studies have investigated white matter integrity in patients with b...

  2. Early brain loss in circuits affected by Alzheimer’s disease is predicted by fornix microstructure but may be independent of gray matter

    Directory of Open Access Journals (Sweden)

    Evan eFletcher

    2014-05-01

    Full Text Available In a cohort of community-recruited elderly subjects with normal cognition at initial evaluation, we found that baseline fornix white matter microstructure was significantly correlated with early volumetric longitudinal tissue change across a region of interest (called fSROI, which overlaps circuits known to be selectively vulnerable to AD pathology. Other white matter and gray matter regions had much weaker or non-existent associations with longitudinal tissue change. Tissue loss in fSROI was in turn a significant factor in a survival model of cognitive decline, as was baseline fornix microstructure. These findings suggest that WM deterioration in the fornix and tissue loss in fSROI may be the early beginnings of posterior limbic circuit and default mode network degeneration. We also found that gray matter baseline volumes in the entorhinal cortex and hippocampus predicted cognitive decline in survival models. But since GM regions did not also significantly predict brain tissue loss, our results may imply a view in which early, prodromal deterioration appears as two quasi independent processes in white and gray matter regions of the limbic circuit crucial to memory.

  3. White Matter Integrity Dissociates Verbal Memory and Auditory Attention Span in Emerging Adults with Congenital Heart Disease.

    Science.gov (United States)

    Brewster, Ryan C; King, Tricia Z; Burns, Thomas G; Drossner, David M; Mahle, William T

    2015-01-01

    White matter disruptions have been identified in individuals with congenital heart disease (CHD). However, no specific theory-driven relationships between microstructural white matter disruptions and cognition have been established in CHD. We conducted a two-part study. First, we identified significant differences in fractional anisotropy (FA) of emerging adults with CHD using Tract-Based Spatial Statistics (TBSS). TBSS analyses between 22 participants with CHD and 18 demographically similar controls identified five regions of normal appearing white matter with significantly lower FA in CHD, and two higher. Next, two regions of lower FA in CHD were selected to examine theory-driven differential relationships with cognition: voxels along the left uncinate fasciculus (UF; a tract theorized to contribute to verbal memory) and voxels along the right middle cerebellar peduncle (MCP; a tract previously linked to attention). In CHD, a significant positive correlation between UF FA and memory was found, r(20)=.42, p=.049 (uncorrected). There was no correlation between UF and auditory attention span. A positive correlation between MCP FA and auditory attention span was found, r(20)=.47, p=.027 (uncorrected). There was no correlation between MCP and memory. In controls, no significant relationships were identified. These results are consistent with previous literature demonstrating lower FA in younger CHD samples, and provide novel evidence for disrupted white matter integrity in emerging adults with CHD. Furthermore, a correlational double dissociation established distinct white matter circuitry (UF and MCP) and differential cognitive correlates (memory and attention span, respectively) in young adults with CHD.

  4. White Matter Structural Differences in Young Children With Type 1 Diabetes: A Diffusion Tensor Imaging Study

    Science.gov (United States)

    Aye, Tandy; Barnea-Goraly, Naama; Ambler, Christian; Hoang, Sherry; Schleifer, Kristin; Park, Yaena; Drobny, Jessica; Wilson, Darrell M.; Reiss, Allan L.; Buckingham, Bruce A.

    2012-01-01

    OBJECTIVE To detect clinical correlates of cognitive abilities and white matter (WM) microstructural changes using diffusion tensor imaging (DTI) in young children with type 1 diabetes. RESEARCH DESIGN AND METHODS Children, ages 3 to <10 years, with type 1 diabetes (n = 22) and age- and sex-matched healthy control subjects (n = 14) completed neurocognitive testing and DTI scans. RESULTS Compared with healthy controls, children with type 1 diabetes had lower axial diffusivity (AD) values (P = 0.046) in the temporal and parietal lobe regions. There were no significant differences between groups in fractional anisotropy and radial diffusivity (RD). Within the diabetes group, there was a significant, positive correlation between time-weighted HbA1c and RD (P = 0.028). A higher, time-weighted HbA1c value was significantly correlated with lower overall intellectual functioning measured by the full-scale intelligence quotient (P = 0.03). CONCLUSIONS Children with type 1 diabetes had significantly different WM structure (as measured by AD) when compared with controls. In addition, WM structural differences (as measured by RD) were significantly correlated with their HbA1c values. Additional studies are needed to determine if WM microstructural differences in young children with type 1 diabetes predict future neurocognitive outcome. PMID:22966090

  5. Peculiarities of vascular tunic microstructure of the white rat eyeball under the effect of opioid.

    Science.gov (United States)

    Mateshuk-Vatseba, Lesya; Pidvalna, Uliana; Kost, Andriy

    2015-01-01

    This article deals with determination of changes in the structural organization of vascular tunic of the eyeball under the effect of opioid. The study was carried out on 24 mature white male rats aged 3.0-4.5 months and 170-280 g weight. The research material included histological specimen and semi-thin sections of white rats' eyeball vascular tunic. For the histological study, microscopic sections of the eyeball were stained with Hematoxylin and Eosin, Heidenhain's Azan trichrome. Specimens were studied and photographed with microscope magnification: ×600, ×1000. The first signs of microstructure disorder in all parts of vascular tunic of the eyeball are noticeable after two weeks of nalbuphine injection to the white rats. During the next four weeks of the experiment, the pathological changes increase and are manifested by the swelling and polymorphonuclear infiltration of the iris, ciliary body, choroid and by deep destructive changes of eyeball hemomicrocirculatory bloodstream. Histological and ultramicroscopic studies of the white rats' eyeball vascular tunic after six weeks of nalbuphine injections showed deep destructive changes in the structure of all parts of vascular tunic. Our study demonstrated a negative effect of the prolonged injection of opioid in the experiment on the state of microstructural organization of the eyeball vascular tunic. Development of angiopathy is the triggering for occurrence of destructive changes in the eyeball under the effect of opioid.

  6. Cellular complexity in subcortical white matter: a distributed control circuit?

    Science.gov (United States)

    Colombo, Jorge A

    2018-03-01

    The subcortical white matter (SWM) has been traditionally considered as a site for passive-neutral-information transfer through cerebral cortex association and projection fibers. Yet, the presence of subcortical neuronal and glial "interstitial" cells expressing immunolabelled neurotransmitters/neuromodulators and synaptic vesicular proteins, and recent immunohistochemical and electrophysiological observations on the rat visual cortex as well as interactive regulation of myelinating processes support the possibility that SWM nests subcortical, regionally variable, distributed neuronal-glial circuits, that could influence information transfer. Their hypothetical involvement in regulating the timing and signal transfer probability at the SWM axonal components ought to be considered and experimentally analysed. Thus, the "interstitial" neuronal cells-associated with local glial cells-traditionally considered to be vestigial and functionally inert under normal conditions, they may well turn to be critical in regulating information transfer at the SWM.

  7. Hemodynamic and metabolic correlates of perinatal white matter injury severity.

    Directory of Open Access Journals (Sweden)

    Art Riddle

    Full Text Available Although the spectrum of perinatal white matter injury (WMI in preterm infants is shifting from cystic encephalomalacia to milder forms of WMI, the factors that contribute to this changing spectrum are unclear. We hypothesized that the variability in WMI quantified by immunohistochemical markers of inflammation could be correlated with the severity of impaired blood oxygen, glucose and lactate.We employed a preterm fetal sheep model of in utero moderate hypoxemia and global severe but not complete cerebral ischemia that reproduces the spectrum of human WMI. Since there is small but measurable residual brain blood flow during occlusion, we sought to determine if the metabolic state of the residual arterial blood was associated with severity of WMI. Near the conclusion of hypoxia-ischemia, we recorded cephalic arterial blood pressure, blood oxygen, glucose and lactate levels. To define the spectrum of WMI, an ordinal WMI rating scale was compared against an unbiased quantitative image analysis protocol that provided continuous histo-pathological outcome measures for astrogliosis and microgliosis derived from the entire white matter.A spectrum of WMI was observed that ranged from diffuse non-necrotic lesions to more severe injury that comprised discrete foci of microscopic or macroscopic necrosis. Residual arterial pressure, oxygen content and blood glucose displayed a significant inverse association with WMI and lactate concentrations were directly related. Elevated glucose levels were the most significantly associated with less severe WMI.Our results suggest that under conditions of hypoxemia and severe cephalic hypotension, WMI severity measured using unbiased immunohistochemical measurements correlated with several physiologic parameters, including glucose, which may be a useful marker of fetal response to hypoxia or provide protection against energy failure and more severe WMI.

  8. White matter correlates of neuropsychological dysfunction in systemic lupus erythematosus.

    Directory of Open Access Journals (Sweden)

    Rex E Jung

    Full Text Available Patients diagnosed with Systemic Lupus Erythematosus have similar levels of neuropsychological dysfunction (i.e., 20-50% as those with Neuropsychiatric Systemic Lupus Erythematosus (NPSLE. We hypothesized a gradient between cognition and white matter integrity, such that strongest brain-behavior relationships would emerge in NPSLE, intermediate in non-NPSLE, and minimal in controls. We studied thirty-one patients (16 non-NPSLE; 15 NPSLE, ranging in age from 18 to 59 years old (100% female, and eighteen age and gender matched healthy controls. DTI examinations were performed on a 1.5T scanner. A broad neuropsychological battery was administered, tapping attention, memory, processing speed, and executive functioning. The Total z-score consisted of the combined sum of all neuropsychological measures. In control subjects, we found no significant FA-Total z-score correlations. NPSLE, non-NPSLE, and control subjects differed significantly in terms of Total z-score (NPSLE = -2.25+/-1.77, non-NPSLE = -1.22+/-1.03, Controls = -0.10+/-.57; F = 13.2, p<.001. In non-NPSLE subjects, FA within the right external capsule was significantly correlated with Total z-score. In NPSLE subjects, the largest FA-Total z-score clusters were observed within the left anterior thalamic radiation and right superior longitudinal fasciculus. In subsequent analyses the largest number of significant voxels linked FA with the Processing Speed z-score in NPSLE. The current results reflect objective white matter correlates of neuropsychological dysfunction in both NPSLE and (to a lesser degree in non-NPSLE. non-NPSLE and NPSLE subjects did not differ significantly in terms of depression, as measured by the GDI; thus, previous hypotheses suggesting moderating effects of depression upon neuropsychological performance do not impact the current FA results.

  9. Effects of low-level sarin and cyclosarin exposure on white matter integrity in Gulf War Veterans.

    Science.gov (United States)

    Chao, Linda L; Zhang, Yu; Buckley, Shannon

    2015-05-01

    We previously found evidence of reduced gray and white matter volume in Gulf War (GW) veterans with predicted low-level exposure to sarin (GB) and cyclosarin (GF). Because loss of white matter tissue integrity has been linked to both gray and white matter atrophy, the current study sought to test the hypothesis that GW veterans with predicted GB/GF exposure have evidence of disrupted white matter microstructural integrity. Measures of fractional anisotropy and directional (i.e., axial and radial) diffusivity were assessed from the 4T diffusion tensor images (DTI) of 59 GW veterans with predicted GB/GF exposure and 59 "matched" unexposed GW veterans (mean age: 48 ± 7 years). The DTI data were analyzed using regions of interest (ROI) analyses that accounted for age, sex, total brain gray and white matter volume, trauma exposure, posttraumatic stress disorder, current major depression, and chronic multisymptom illness status. There were no significant group differences in fractional anisotropy or radial diffusivity. However, there was increased axial diffusivity in GW veterans with predicted GB/GF exposure compared to matched, unexposed veterans throughout the brain, including the temporal stem, corona radiata, superior and inferior (hippocampal) cingulum, inferior and superior fronto-occipital fasciculus, internal and external capsule, and superficial cortical white matter blades. Post hoc analysis revealed significant correlations between higher fractional anisotropy and lower radial diffusivity with better neurobehavioral performance in unexposed GW veterans. In contrast, only increased axial diffusivity in posterior limb of the internal capsule was associated with better psychomotor function in GW veterans with predicted GB/GF exposure. The finding that increased axial diffusivity in a region of the brain that contains descending corticospinal fibers was associated with better psychomotor function and the lack of significant neurobehavioral deficits in veterans

  10. Considerations for the optimization of induced white matter injury preclinical models

    Directory of Open Access Journals (Sweden)

    Abdullah Shafique Ahmad

    2015-08-01

    Full Text Available The white matter injury in relation to acute neurologic conditions, especially stroke, has remained obscure until recently. Current advances in the imaging technologies in the field of stroke have confirmed that white matter injury plays an important role in the prognosis of stroke and suggest that white matter protection is essential for functional recovery and post-stroke rehabilitation. However, due to the lack of a reproducible animal model of white matter injury, the pathophysiology and mechanisms of this injury are not well studied. Moreover, producing selective white matter injury in animals, especially in rodents, has proven to be challenging. Problems associated with inducing selective white matter ischemic injury in the rodent derive from differences in the architecture of the brain, most particularly the ratio of white matter to gray matter in rodents compared to humans, the agents used to induce the injury, and the location of the injury. Aging, gender differences, and comorbidities further add to this complexity. This review provides a brief account of the techniques commonly used to induce general white matter injury in animal models (stroke and non-stroke related and highlights relevance, optimization issues, and translational potentials associated with this particular form of injury.

  11. Shades of white : diffusion properties of T1- and FLAIR-defined white matter signal abnormalities differ in stages from cognitively normal to dementia

    NARCIS (Netherlands)

    Riphagen, Joost M.; Gronenschild, Ed HBM; Salat, David H.; Freeze, Whitney M.; Ivanov, Dimo; Clerx, Lies; Verhey, Frans R. J.; Aalten, Pauline; Jacobs, Heidi I. L.

    The underlying pathology of white matter signal abnormalities (WMSAs) is heterogeneous and may vary dependent on the magnetic resonance imaging contrast used to define them. We investigated differences in white matter diffusivity as an indicator for white matter integrity underlying WMSA based on

  12. Episodic memory function is associated with multiple measures of white matter integrity in cognitive aging

    Directory of Open Access Journals (Sweden)

    Samuel Neal Lockhart

    2012-03-01

    Full Text Available Previous neuroimaging research indicates that white matter injury and integrity, measured respectively by white matter hyperintensities (WMH and fractional anisotropy (FA obtained from diffusion tensor imaging, differ with aging and cerebrovascular disease and are associated with episodic memory deficits in cognitively normal older adults. However, knowledge about tract-specific relationships between WMH, FA, and episodic memory in aging remains limited. We hypothesized that white matter connections between frontal cortex and subcortical structures as well as connections between frontal and temporo-parietal cortex would be most affected. In the current study, we examined relationships between WMH, FA and episodic memory in 15 young adults, 13 elders with minimal WMH and 15 elders with extensive WMH, using an episodic recognition memory test for object-color associations. Voxel-based statistics were used to identify voxel clusters where white matter measures were specifically associated with variations in episodic memory performance, and white matter tracts intersecting these clusters were analyzed to examine white matter-memory relationships. White matter injury and integrity measures were significantly associated with episodic memory in extensive regions of white matter, located predominantly in frontal, parietal, and subcortical regions. Template based tractography indicated that white matter injury, as measured by WMH, in the uncinate and inferior longitudinal fasciculi were significantly negatively associated with episodic memory performance. Other tracts such as thalamo-frontal projections, superior longitudinal fasciculus, and dorsal cingulum bundle demonstrated strong negative associations as well. The results suggest that white matter injury to multiple pathways, including connections of frontal and temporal cortex and frontal-subcortical white matter tracts, plays a critical role in memory differences seen in older individuals.

  13. White Matter Hyperintensity Volume and Cerebral Perfusion in Older Individuals with Hypertension Using Arterial Spin-Labeling

    NARCIS (Netherlands)

    van Dalen, J. W.; Mutsaerts, H. J. M. M.; Nederveen, A. J.; Vrenken, H.; Steenwijk, M. D.; Caan, M. W. A.; Majoie, C. B. L. M.; van Gool, W. A.; Richard, E.

    2016-01-01

    BACKGROUND AND PURPOSE: White matter hyperintensities of presumed vascular origin in elderly patients with hypertension may be part of a general cerebral perfusion deficit, involving not only the white matter hyperintensities but also the surrounding normal-appearing white matter and gray matter. We

  14. Gray/White Matter Contrast in Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Carme Uribe

    2018-03-01

    Full Text Available Gray/white matter contrast (GWC decreases with aging and has been found to be a useful MRI biomarker in Alzheimer’s disease (AD, but its utility in Parkinson’s disease (PD patients has not been investigated. The aims of the study were to test whether GWC is sensitive to aging changes in PD patients, if PD patients differ from healthy controls (HCs in GWC, and whether the use of GWC data would improve the sensitivity of cortical thickness analyses to differentiate PD patients from controls. Using T1-weighted structural images, we obtained individual cortical thickness and GWC values from a sample of 90 PD patients and 27 controls. Images were processed with the automated FreeSurfer stream. GWC was computed by dividing the white matter (WM by the gray matter (GM values and projecting the ratios onto a common surface. The sample characteristics were: 52 patients and 14 controls were males; mean age of 64.4 ± 10.6 years in PD and 64.7 ± 8.6 years in controls; 8.0 ± 5.6 years of disease evolution; 15.6 ± 9.8 UPDRS; and a range of 1.5–3 in Hoehn and Yahr (H&Y stage. In both PD and controls we observed significant correlations between GWC and age involving almost the entire cortex. When applying a stringent cluster-forming threshold of p < 0.0001, the correlation between GWC and age also involved the entire cortex in the PD group; in the control group, the correlation was found in the parahippocampal gyrus and widespread frontal and parietal areas. The GWC of PD patients did not differ from controls’, whereas cortical thickness analyses showed thinning in temporal and parietal cortices in the PD group. Cortical thinning remained unchanged after adjusting for GWC. GWC is a very sensitive measure for detecting aging effects, but did not provide additional information over other parameters of atrophy in PD.

  15. White matter atrophy and cognitive dysfunctions in neuromyelitis optica.

    Directory of Open Access Journals (Sweden)

    Frederic Blanc

    Full Text Available Neuromyelitis optica (NMO is an inflammatory disease of central nervous system characterized by optic neuritis and longitudinally extensive acute transverse myelitis. NMO patients have cognitive dysfunctions but other clinical symptoms of brain origin are rare. In the present study, we aimed to investigate cognitive functions and brain volume in NMO. The study population consisted of 28 patients with NMO and 28 healthy control subjects matched for age, sex and educational level. We applied a French translation of the Brief Repeatable Battery (BRB-N to the NMO patients. Using SIENAx for global brain volume (Grey Matter, GM; White Matter, WM; and whole brain and VBM for focal brain volume (GM and WM, NMO patients and controls were compared. Voxel-level correlations between diminished brain concentration and cognitive performance for each tests were performed. Focal and global brain volume of NMO patients with and without cognitive impairment were also compared. Fifteen NMO patients (54% had cognitive impairment with memory, executive function, attention and speed of information processing deficits. Global and focal brain atrophy of WM but not Grey Matter (GM was found in the NMO patients group. The focal WM atrophy included the optic chiasm, pons, cerebellum, the corpus callosum and parts of the frontal, temporal and parietal lobes, including superior longitudinal fascicle. Visual memory, verbal memory, speed of information processing, short-term memory and executive functions were correlated to focal WM volumes. The comparison of patients with, to patients without cognitive impairment showed a clear decrease of global and focal WM, including brainstem, corticospinal tracts, corpus callosum but also superior and inferior longitudinal fascicles. Cognitive impairment in NMO patients is correlated to the decreased of global and focal WM volume of the brain. Further studies are needed to better understand the precise origin of cognitive impairment in

  16. Quantifying Cerebellum Grey Matter and White Matter Perfusion Using Pulsed Arterial Spin Labeling

    Directory of Open Access Journals (Sweden)

    Xiufeng Li

    2014-01-01

    Full Text Available To facilitate quantification of cerebellum cerebral blood flow (CBF, studies were performed to systematically optimize arterial spin labeling (ASL parameters for measuring cerebellum perfusion, segment cerebellum to obtain separate CBF values for grey matter (GM and white matter (WM, and compare FAIR ASST to PICORE. Cerebellum GM and WM CBF were measured with optimized ASL parameters using FAIR ASST and PICORE in five subjects. Influence of volume averaging in voxels on cerebellar grey and white matter boundaries was minimized by high-probability threshold masks. Cerebellar CBF values determined by FAIR ASST were 43.8 ± 5.1 mL/100 g/min for GM and 27.6 ± 4.5 mL/100 g/min for WM. Quantitative perfusion studies indicated that CBF in cerebellum GM is 1.6 times greater than that in cerebellum WM. Compared to PICORE, FAIR ASST produced similar CBF estimations but less subtraction error and lower temporal, spatial, and intersubject variability. These are important advantages for detecting group and/or condition differences in CBF values.

  17. Quantifying cerebellum grey matter and white matter perfusion using pulsed arterial spin labeling.

    Science.gov (United States)

    Li, Xiufeng; Sarkar, Subhendra N; Purdy, David E; Briggs, Richard W

    2014-01-01

    To facilitate quantification of cerebellum cerebral blood flow (CBF), studies were performed to systematically optimize arterial spin labeling (ASL) parameters for measuring cerebellum perfusion, segment cerebellum to obtain separate CBF values for grey matter (GM) and white matter (WM), and compare FAIR ASST to PICORE. Cerebellum GM and WM CBF were measured with optimized ASL parameters using FAIR ASST and PICORE in five subjects. Influence of volume averaging in voxels on cerebellar grey and white matter boundaries was minimized by high-probability threshold masks. Cerebellar CBF values determined by FAIR ASST were 43.8 ± 5.1 mL/100 g/min for GM and 27.6 ± 4.5 mL/100 g/min for WM. Quantitative perfusion studies indicated that CBF in cerebellum GM is 1.6 times greater than that in cerebellum WM. Compared to PICORE, FAIR ASST produced similar CBF estimations but less subtraction error and lower temporal, spatial, and intersubject variability. These are important advantages for detecting group and/or condition differences in CBF values.

  18. Quantifying Cerebellum Grey Matter and White Matter Perfusion Using Pulsed Arterial Spin Labeling

    Science.gov (United States)

    Li, Xiufeng; Sarkar, Subhendra N.; Purdy, David E.; Briggs, Richard W.

    2014-01-01

    To facilitate quantification of cerebellum cerebral blood flow (CBF), studies were performed to systematically optimize arterial spin labeling (ASL) parameters for measuring cerebellum perfusion, segment cerebellum to obtain separate CBF values for grey matter (GM) and white matter (WM), and compare FAIR ASST to PICORE. Cerebellum GM and WM CBF were measured with optimized ASL parameters using FAIR ASST and PICORE in five subjects. Influence of volume averaging in voxels on cerebellar grey and white matter boundaries was minimized by high-probability threshold masks. Cerebellar CBF values determined by FAIR ASST were 43.8 ± 5.1 mL/100 g/min for GM and 27.6 ± 4.5 mL/100 g/min for WM. Quantitative perfusion studies indicated that CBF in cerebellum GM is 1.6 times greater than that in cerebellum WM. Compared to PICORE, FAIR ASST produced similar CBF estimations but less subtraction error and lower temporal, spatial, and intersubject variability. These are important advantages for detecting group and/or condition differences in CBF values. PMID:24949416

  19. Swelling of whey and egg white protein hydrogels with stranded and particulate microstructures.

    Science.gov (United States)

    Li, Hui; Zhao, Lei; Chen, Xiao Dong; Mercadé-Prieto, Ruben

    2016-02-01

    Swelling of protein hydrogels in alkaline conditions strongly depends on the gel microstructure. Stranded transparent gels swell as predicted using a modified Flory-Rehner model with the net protein charge. Particulate opaque gels swell very differently, with a sudden increase at a narrow pH range. Its swelling is not controlled by the protein charge, but by the destruction of the non-covalent interactions. Comparable dissolution thresholds, one with pH and another with the degree of swelling, are observed in both types of microstructures. These conclusions are valid for both whey protein isolate (WPI) gels and egg white gels, suggesting that they are universal for all globular proteins that can form such microscructures. Differences are observed, however, from the prevalent chemical crosslinks in each protein system. Non-covalent interactions dominate WPI gels; when such interactions are destroyed at pH≥11.5 the gels swell extensively and eventually dissolve. In egg white gels, the higher degree of disulphide crosslinking allows extensive swelling when non-covalent interactions are destroyed, but dissolution only occurs at pH≥13 when covalent crosslinks are cleaved. The current study highlights that the microstructure of protein hydrogels, a unique particularity of protein systems compared to other synthetic hydrogels, defines swelling. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Lifelong bilingualism contributes to cognitive reserve against white matter integrity declines in aging.

    Science.gov (United States)

    Gold, Brian T; Johnson, Nathan F; Powell, David K

    2013-11-01

    Recent evidence suggests that lifelong bilingualism may contribute to cognitive reserve (CR) in normal aging. However, there is currently no neuroimaging evidence to suggest that lifelong bilinguals can retain normal cognitive functioning in the face of age-related neurodegeneration. Here we explored this issue by comparing white matter (WM) integrity and gray matter (GM) volumetric patterns of older adult lifelong bilinguals (N=20) and monolinguals (N=20). The groups were matched on a range of relevant cognitive test scores and on the established CR variables of education, socioeconomic status and intelligence. Participants underwent high-resolution structural imaging for assessment of GM volume and diffusion tensor imaging (DTI) for assessment of WM integrity. Results indicated significantly lower microstructural integrity in the bilingual group in several WM tracts. In particular, compared to their monolingual peers, the bilingual group showed lower fractional anisotropy and/or higher radial diffusivity in the inferior longitudinal fasciculus/inferior fronto-occipital fasciculus bilaterally, the fornix, and multiple portions of the corpus callosum. There were no group differences in GM volume. Our results suggest that lifelong bilingualism contributes to CR against WM integrity declines in aging. © 2013 Published by Elsevier Ltd.

  1. Diffusion tensor imaging, white matter lesions, the corpus callosum, and gait in the elderly

    Science.gov (United States)

    Gait impairment is common in the elderly, especially affected by stroke and white matter hyper intensities found in conventional brain magnetic resonance imaging (MRI). Diffusion tensor imaging (DTI) is more sensitive to white matter damage than conventional MRI. The relationship between DTI measure...

  2. Depressive Symptoms in Adolescents: Associations with White Matter Volume and Marijuana Use

    Science.gov (United States)

    Medina, Krista Lisdahl; Nagel, Bonnie J.; Park, Ann; McQueeny, Tim; Tapert, Susan F.

    2007-01-01

    Background: Depressed mood has been associated with decreased white matter and reduced hippocampal volumes. However, the relationship between brain structure and mood may be unique among adolescents who use marijuana heavily. The goal of this study was to examine the relationship between white matter and hippocampal volumes and depressive symptoms…

  3. Decoupling of structural and functional brain connectivity in older adults with white matter hyperintensities

    NARCIS (Netherlands)

    Reijmer, Y. D.; Schultz, A. P.; Leemans, A.; O'Sullivan, M. J.; Gurol, M. E.; Sperling, R.; Greenberg, S. M.; Viswanathan, A.; Hedden, T.

    2015-01-01

    Age-related impairments in the default network (DN) have been related to disruptions in connecting white matter tracts. We hypothesized that the local correlation between DN structural and functional connectivity is negatively affected in the presence of global white matter injury. In 125 clinically

  4. Growth of White Matter in the Adolescent Brain: Myelin or Axon?

    Science.gov (United States)

    Paus, Tomas

    2010-01-01

    White matter occupies almost half of the human brain. It contains axons connecting spatially segregated modules and, as such, it is essential for the smooth flow of information in functional networks. Structural maturation of white matter continues during adolescence, as reflected in age-related changes in its volume, as well as in its…

  5. A semi-automated method for measuring thickness and white matter ...

    African Journals Online (AJOL)

    A semi-automated method for measuring thickness and white matter integrity of the corpus callosum. ... and interhemispheric differences. Future research will determine normal values for age and compare CC thickness with peripheral white matter volume loss in large groups of patients, using the semiautomated technique.

  6. Gestational age at birth and brain white matter development in term-born infants and children

    Science.gov (United States)

    Studies on infants/children born preterm have shown that adequate gestational length is critical for brain white matter development. Less is known regarding how variations in gestational age at birth in term infants/children affect white matter development, which was evaluated in this study. Using d...

  7. Does functional MRI detect activation in white matter? A review of emerging evidence, issues, and future directions

    Science.gov (United States)

    Gawryluk, Jodie R.; Mazerolle, Erin L.; D'Arcy, Ryan C. N.

    2014-01-01

    Functional magnetic resonance imaging (fMRI) is a non-invasive technique that allows for visualization of activated brain regions. Until recently, fMRI studies have focused on gray matter. There are two main reasons white matter fMRI remains controversial: (1) the blood oxygen level dependent (BOLD) fMRI signal depends on cerebral blood flow and volume, which are lower in white matter than gray matter and (2) fMRI signal has been associated with post-synaptic potentials (mainly localized in gray matter) as opposed to action potentials (the primary type of neural activity in white matter). Despite these observations, there is no direct evidence against measuring fMRI activation in white matter and reports of fMRI activation in white matter continue to increase. The questions underlying white matter fMRI activation are important. White matter fMRI activation has the potential to greatly expand the breadth of brain connectivity research, as well as improve the assessment and diagnosis of white matter and connectivity disorders. The current review provides an overview of the motivation to investigate white matter fMRI activation, as well as the published evidence of this phenomenon. We speculate on possible neurophysiologic bases of white matter fMRI signals, and discuss potential explanations for why reports of white matter fMRI activation are relatively scarce. We end with a discussion of future basic and clinical research directions in the study of white matter fMRI. PMID:25152709

  8. White Matter Damage Relates to Oxygen Saturation in Children With Sickle Cell Anemia Without Silent Cerebral Infarcts.

    Science.gov (United States)

    Kawadler, Jamie M; Kirkham, Fenella J; Clayden, Jonathan D; Hollocks, Matthew J; Seymour, Emma L; Edey, Rosanna; Telfer, Paul; Robins, Andrew; Wilkey, Olu; Barker, Simon; Cox, Tim C S; Clark, Chris A

    2015-07-01

    Sickle cell anemia is associated with compromised oxygen-carrying capability of hemoglobin and a high incidence of overt and silent stroke. However, in children with no evidence of cerebral infarction, there are changes in brain morphometry relative to healthy controls, which may be related to chronic anemia and oxygen desaturation. A whole-brain tract-based spatial statistics analysis was carried out in 25 children with sickle cell anemia with no evidence of abnormality on T2-weighted magnetic resonance imaging (13 male, age range: 8-18 years) and 14 age- and race-matched controls (7 male, age range: 10-19 years) to determine the extent of white matter injury. The hypotheses that white matter damage is related to daytime peripheral oxygen saturation and steady-state hemoglobin were tested. Fractional anisotropy was found to be significantly lower in patients in the subcortical white matter (corticospinal tract and cerebellum), whereas mean diffusivity and radial diffusivity were higher in patients in widespread areas. There was a significant negative relationship between radial diffusivity and oxygen saturation (Plevel negative relationship between radial diffusivity and hemoglobin (Pcell anemia, and provides for the first time direct evidence of a relationship between brain microstructure and markers of disease severity (eg, peripheral oxygen saturation and steady-state hemoglobin). This study suggests that diffusion tensor imaging metrics may serve as a biomarker for future trials of reducing hypoxic exposure. © 2015 American Heart Association, Inc.

  9. Whole-brain voxel-based morphometry of white matter in medial temporal lobe epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Yu Aihong [Department of Radiology, Xuanwu Hospital, Capital University of Medical Sciences, Beijing 100053 (China); Li Kuncheng [Department of Radiology, Xuanwu Hospital, Capital University of Medical Sciences, Beijing 100053 (China)], E-mail: Likuncheng@vip.sina.com; Li Lin; Shan Baoci [Institute of High Energy Physics, Chinese Academy of Sciences (China); Wang Yuping; Xue Sufang [Department of Neurology, Xuanwu Hospital, Capital University of Medical Sciences (China)

    2008-01-15

    Purpose: The purpose of this study was to analyze whole-brain white matter changes in medial temporal lobe epilepsy (MTLE). Materials and methods: We studied 23 patients with MTLE and 13 age- and sex-matched healthy control subjects using voxel-based morphometry (VBM) on T1-weighted 3D datasets. The seizure focus was right sided in 11 patients and left sided in 12. The data were collected on a 1.5 T MR system and analyzed by SPM 99 to generate white matter density maps. Results: Voxel-based morphometry revealed diffusively reduced white matter in MTLE prominently including bilateral frontal lobes, bilateral temporal lobes and corpus callosum. White matter reduction was also found in the bilateral cerebellar hemispheres in the left MTLE group. Conclusion: VBM is a simple and automated approach that is able to identify diffuse whole-brain white matter reduction in MTLE.

  10. Whole-brain voxel-based morphometry of white matter in medial temporal lobe epilepsy

    International Nuclear Information System (INIS)

    Yu Aihong; Li Kuncheng; Li Lin; Shan Baoci; Wang Yuping; Xue Sufang

    2008-01-01

    Purpose: The purpose of this study was to analyze whole-brain white matter changes in medial temporal lobe epilepsy (MTLE). Materials and methods: We studied 23 patients with MTLE and 13 age- and sex-matched healthy control subjects using voxel-based morphometry (VBM) on T1-weighted 3D datasets. The seizure focus was right sided in 11 patients and left sided in 12. The data were collected on a 1.5 T MR system and analyzed by SPM 99 to generate white matter density maps. Results: Voxel-based morphometry revealed diffusively reduced white matter in MTLE prominently including bilateral frontal lobes, bilateral temporal lobes and corpus callosum. White matter reduction was also found in the bilateral cerebellar hemispheres in the left MTLE group. Conclusion: VBM is a simple and automated approach that is able to identify diffuse whole-brain white matter reduction in MTLE

  11. Measurement of chromatic dispersion of microstructured polymer fibers by white-light spectral interferometry

    DEFF Research Database (Denmark)

    Hlubina, Petr; Ciprian, Dalibor; Frosz, Michael Henoch

    2009-01-01

    We present a white-light spectral interferometric method for measuring the chromatic dispersion of microstructured fibers made of polymethyl methacrylate (PMMA). The method uses an unbalanced Mach-Zehnder interferometer with the fiber of known length placed in one of the interferometer arms...... of the method by measuring the wavelength dependence of the differential group refractive index of a pure silica fiber. We apply a five-term power series fit to the measured data and confirm by its differentiation that the chromatic dispersion of pure silica glass agrees well with theory. Second, we measure...... the chromatic dispersion for the fundamental mode supported by two different PMMA microstructured fibers, the multimode fiber and the large-mode area one....

  12. Clinical significance of circulating vascular cell adhesion molecule-1 to white matter disintegrity in Alzheimer's dementia.

    Science.gov (United States)

    Huang, Chi-Wei; Tsai, Meng-Han; Chen, Nai-Ching; Chen, Wei-Hsi; Lu, Yan-Ting; Lui, Chun-Chung; Chang, Ya-Ting; Chang, Wen-Neng; Chang, Alice Y W; Chang, Chiung-Chih

    2015-11-25

    Endothelial dysfunction leads to worse cognitive performance in Alzheimer's dementia (AD). While both cerebrovascular risk factors and endothelial dysfunction lead to activation of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and E-selectin, it is not known whether these biomarkers extend the diagnostic repertoire in reflecting intracerebral structural damage or cognitive performance. A total of 110 AD patients and 50 age-matched controls were enrolled. Plasma levels of VCAM-1, ICAM-1 and E-selectin were measured and correlated with the cognitive performance, white matter macro-structural changes, and major tract-specific fractional anisotropy quantification. The AD patients were further stratified by clinical dementia rating score (mild dementia, n=60; moderate-to-severe dementia, n=50). Compared with the controls, plasma levels of VCAM-1 (p< 0.001), ICAM-1 (p=0.028) and E-selectin (p=0.016) were significantly higher in the patients, but only VCAM-1 levels significantly reflected the severity of dementia (p< 0.001). In addition, only VCAM-1 levels showed an association with macro- and micro- white matter changes especially in the superior longitudinal fasciculus (p< 0.001), posterior thalamic radiation (p=0.002), stria terminalis (p=0.002) and corpus callosum (p=0.009), and were independent of, age and cortical volume. These tracts show significant association with MMSE, short term memory and visuospatial function. Meanwhile, while VCAM-1 level correlated significantly with short-term memory (p=0.026) and drawing (p=0.025) scores in the AD patients after adjusting for age and education, the significance disappeared after adjusting for global FA. Endothelial activation, especially VCAM-1, was of clinical significance in AD that reflects macro- and micro-structural changes and poor short term memory and visuospatial function.

  13. White matter integrity of the medial forebrain bundle and attention and working memory deficits following traumatic brain injury.

    Science.gov (United States)

    Owens, Jacqueline A; Spitz, Gershon; Ponsford, Jennie L; Dymowski, Alicia R; Ferris, Nicholas; Willmott, Catherine

    2017-02-01

    The medial forebrain bundle (MFB) contains ascending catecholamine fibers that project to the prefrontal cortex (PFC). Damage to these fibers following traumatic brain injury (TBI) may alter extracellular catecholamine levels in the PFC and impede attention and working memory ability. This study investigated white matter microstructure of the medial MFB, specifically the supero-lateral branch (slMFB), following TBI, and its association with performance on attention and working memory tasks. Neuropsychological measures of attention and working memory were administered to 20 moderate-severe participants with TBI (posttraumatic amnesia M  = 40.05 ± 37.10 days, median time since injury 10.48 months, range 3.72-87.49) and 20 healthy controls. Probabilistic tractography was used to obtain fractional anisotropy (FA) and mean diffusivity (MD) values for 17 participants with TBI and 20 healthy controls. When compared to controls, participants with TBI were found to have significantly lower FA ( p  attention task, n -back, and Symbol Digit Modalities Test. This study was the first to demonstrate microstructural white matter damage within the slMFB following TBI. However, no evidence was found for an association of alterations to this tract and performance on attentional tasks.

  14. Comorbidities, confounders, and the white matter transcriptome in chronic alcoholism.

    Science.gov (United States)

    Sutherland, Greg T; Sheedy, Donna; Sheahan, Pam J; Kaplan, Warren; Kril, Jillian J

    2014-04-01

    Alcohol abuse is the world's third leading cause of disease and disability, and one potential sequel of chronic abuse is alcohol-related brain damage (ARBD). This clinically manifests as cognitive dysfunction and pathologically as atrophy of white matter (WM) in particular. The mechanism linking chronic alcohol intoxication with ARBD remains largely unknown but it is also complicated by common comorbidities such as liver damage and nutritional deficiencies. Liver cirrhosis, in particular, often leads to hepatic encephalopathy (HE), a primary glial disease. In a novel transcriptomic study, we targeted the WM only of chronic alcoholics in an attempt to tease apart the pathogenesis of ARBD. Specifically, in alcoholics with and without HE, we explored both the prefrontal and primary motor cortices, 2 regions that experience differential levels of neuronal loss. Our results suggest that HE, along with 2 confounders, gray matter contamination, and low RNA quality are major drivers of gene expression in ARBD. All 3 exceeded the effects of alcohol itself. In particular, low-quality RNA samples were characterized by an up-regulation of translation machinery, while HE was associated with a down-regulation of mitochondrial energy metabolism pathways. The findings in HE alcoholics are consistent with the metabolic acidosis seen in this condition. In contrast non-HE alcoholics had widespread but only subtle changes in gene expression in their WM. Notwithstanding the latter result, this study demonstrates that significant confounders in transcriptomic studies of human postmortem brain tissue can be identified, quantified, and "removed" to reveal disease-specific signals. Copyright © 2014 by the Research Society on Alcoholism.

  15. Pathological changes in the white matter after spinal contusion injury in the rat.

    Directory of Open Access Journals (Sweden)

    C Joakim Ek

    Full Text Available It has been shown previously that after spinal cord injury, the loss of grey matter is relatively faster than loss of white matter suggesting interventions to save white matter tracts offer better therapeutic possibilities. Loss of white matter in and around the injury site is believed to be the main underlying cause for the subsequent loss of neurological functions. In this study we used a series of techniques, including estimations of the number of axons with pathology, immunohistochemistry and mapping of distribution of pathological axons, to better understand the temporal and spatial pathological events in white matter following contusion injury to the rat spinal cord. There was an initial rapid loss of axons with no detectable further loss beyond 1 week after injury. Immunoreactivity for CNPase indicated that changes to oligodendrocytes are rapid, extending to several millimetres away from injury site and preceding much of the axonal loss, giving early prediction of the final volume of white matter that survived. It seems that in juvenile rats the myelination of axons in white matter tracts continues for some time, which has an important bearing on interpretation of our, and previous, studies. The amount of myelin debris and axon pathology progressively decreased with time but could still be observed at 10 weeks after injury, especially at more distant rostral and caudal levels from the injury site. This study provides new methods to assess injuries to spinal cord and indicates that early interventions are needed for the successful sparing of white matter tracts following injury.

  16. Brain white matter changes associated with urological chronic pelvic pain syndrome: Multi-site neuroimaging from a MAPP case-control study

    Science.gov (United States)

    Huang, Lejian; Kutch, Jason J.; Ellingson, Benjamin M.; Martucci, Katherine T.; Harris, Richard E.; Clauw, Daniel J.; Mackey, Sean; Mayer, Emeran A.; Schaeffer, Anthony J.; Apkarian, A. Vania; Farmer, Melissa A.

    2016-01-01

    Clinical phenotyping of urological chronic pelvic pain syndromes (UCPPS) in men and women has focused on end-organ abnormalities to identify putative clinical subtypes. Initial evidence of abnormal brain function and structure in male pelvic pain has necessitated large-scale, multi-site investigations into potential UCPPS brain biomarkers. We present the first evidence of regional white matter (axonal) abnormalities in men and women with UCPPS, compared to positive (irritable bowel syndrome, IBS) and healthy controls. Epidemiological and neuroimaging data was collected from participants with UCPPS (n=52), IBS (n=39), and healthy, sex- and age-matched controls (n=61). White matter microstructure, measured as fractional anisotropy (FA), was examined with diffusion tensor imaging (DTI). Group differences in regional FA positively correlated with pain severity, including segments of the right corticospinal tract and right anterior thalamic radiation. Increased corticospinal FA was specific and sensitive to UCPPS, positively correlated with pain severity, and reflected sensory (not affective) features of pain. Reduced anterior thalamic radiation FA distinguished IBS from UCPPS patients and controls, suggesting greater microstructural divergence from normal tract organization. Findings confirm that regional white matter abnormalities characterize UCPPS and can distinguish between visceral diagnoses, suggesting that regional axonal microstructure is either altered with ongoing pain or predisposes its development. PMID:27842046

  17. Normal development of human brain white matter from infancy to early adulthood: a diffusion tensor imaging study.

    Science.gov (United States)

    Uda, Satoshi; Matsui, Mie; Tanaka, Chiaki; Uematsu, Akiko; Miura, Kayoko; Kawana, Izumi; Noguchi, Kyo

    2015-01-01

    Diffusion tensor imaging (DTI), which measures the magnitude of anisotropy of water diffusion in white matter, has recently been used to visualize and quantify parameters of neural tracts connecting brain regions. In order to investigate the developmental changes and sex and hemispheric differences of neural fibers in normal white matter, we used DTI to examine 52 healthy humans ranging in age from 2 months to 25 years. We extracted the following tracts of interest (TOIs) using the region of interest method: the corpus callosum (CC), cingulum hippocampus (CGH), inferior longitudinal fasciculus (ILF), and superior longitudinal fasciculus (SLF). We measured fractional anisotropy (FA), apparent diffusion coefficient (ADC), axial diffusivity (AD), and radial diffusivity (RD). Approximate values and changes in growth rates of all DTI parameters at each age were calculated and analyzed using LOESS (locally weighted scatterplot smoothing). We found that for all TOIs, FA increased with age, whereas ADC, AD and RD values decreased with age. The turning point of growth rates was at approximately 6 years. FA in the CC was greater than that in the SLF, ILF and CGH. Moreover, FA, ADC and AD of the splenium of the CC (sCC) were greater than in the genu of the CC (gCC), whereas the RD of the sCC was lower than the RD of the gCC. The FA of right-hemisphere TOIs was significantly greater than that of left-hemisphere TOIs. In infants, growth rates of both FA and RD were larger than those of AD. Our data show that developmental patterns differ by TOIs and myelination along with the development of white matter, which can be mainly expressed as an increase in FA together with a decrease in RD. These findings clarify the long-term normal developmental characteristics of white matter microstructure from infancy to early adulthood. © 2015 S. Karger AG, Basel.

  18. White matter alterations and their associations with motor function in young adults born preterm with very low birth weight

    Directory of Open Access Journals (Sweden)

    Ingrid Marie Husby Hollund

    2018-01-01

    Full Text Available Very low birth weight (VLBW: ≤1500 g individuals have an increased risk of white matter alterations and neurodevelopmental problems, including fine and gross motor problems. In this hospital-based follow-up study, the main aim was to examine white matter microstructure and its relationship to fine and gross motor function in 31 VLBW young adults without cerebral palsy compared with 31 term-born controls, at mean age 22.6 ± 0.7 years. The participants were examined with tests of fine and gross motor function (Trail Making Test-5: TMT-5, Grooved Pegboard, Triangle from Movement Assessment Battery for Children-2: MABC-2 and High-level Mobility Assessment Tool: HiMAT and diffusion tensor imaging (DTI. Probabilistic tractography of motor pathways of the corticospinal tract (CST and corpus callosum (CC was performed. Fractional anisotropy (FA was calculated in non-crossing (capsula interna in CST, body of CC and crossing (centrum semiovale fibre regions along the tracts and examined for group differences. Associations between motor test scores and FA in the CST and CC were investigated with linear regression. Tract-based spatial statistics (TBSS was used to examine group differences in DTI metrics in all major white matter tracts. The VLBW group had lower scores on all motor tests compared with controls, however, only statistically significant for TMT-5. Based on tractography, FA in the VLBW group was lower in non-crossing fibre regions and higher in crossing fibre regions of the CST compared with controls. Within the VLBW group, poorer fine motor function was associated with higher FA in crossing fibre regions of the CST, and poorer bimanual coordination was additionally associated with lower FA in crossing fibre regions of the CC. Poorer gross motor function was associated with lower FA in crossing fibre regions of the CST and CC. There were no associations between motor function and FA in non-crossing fibre regions of the CST and CC within

  19. White matter alterations and their associations with motor function in young adults born preterm with very low birth weight.

    Science.gov (United States)

    Hollund, Ingrid Marie Husby; Olsen, Alexander; Skranes, Jon; Brubakk, Ann-Mari; Håberg, Asta K; Eikenes, Live; Evensen, Kari Anne I

    2018-01-01

    Very low birth weight (VLBW: ≤ 1500 g) individuals have an increased risk of white matter alterations and neurodevelopmental problems, including fine and gross motor problems. In this hospital-based follow-up study, the main aim was to examine white matter microstructure and its relationship to fine and gross motor function in 31 VLBW young adults without cerebral palsy compared with 31 term-born controls, at mean age 22.6 ± 0.7 years. The participants were examined with tests of fine and gross motor function (Trail Making Test-5: TMT-5, Grooved Pegboard, Triangle from Movement Assessment Battery for Children-2: MABC-2 and High-level Mobility Assessment Tool: HiMAT) and diffusion tensor imaging (DTI). Probabilistic tractography of motor pathways of the corticospinal tract (CST) and corpus callosum (CC) was performed. Fractional anisotropy (FA) was calculated in non-crossing (capsula interna in CST, body of CC) and crossing (centrum semiovale) fibre regions along the tracts and examined for group differences. Associations between motor test scores and FA in the CST and CC were investigated with linear regression. Tract-based spatial statistics (TBSS) was used to examine group differences in DTI metrics in all major white matter tracts. The VLBW group had lower scores on all motor tests compared with controls, however, only statistically significant for TMT-5. Based on tractography, FA in the VLBW group was lower in non-crossing fibre regions and higher in crossing fibre regions of the CST compared with controls. Within the VLBW group, poorer fine motor function was associated with higher FA in crossing fibre regions of the CST, and poorer bimanual coordination was additionally associated with lower FA in crossing fibre regions of the CC. Poorer gross motor function was associated with lower FA in crossing fibre regions of the CST and CC. There were no associations between motor function and FA in non-crossing fibre regions of the CST and CC within the VLBW

  20. White Matter Hyperintensities Are Under Strong Genetic Influence.

    Science.gov (United States)

    Sachdev, Perminder S; Thalamuthu, Anbupalam; Mather, Karen A; Ames, David; Wright, Margaret J; Wen, Wei

    2016-06-01

    The genetic basis of white matter hyperintensities (WMH) is still unknown. This study examines the heritability of WMH in both sexes and in different brain regions, and the influence of age. Participants from the Older Australian Twins Study were recruited (n=320; 92 monozygotic and 68 dizygotic pairs) who volunteered for magnetic resonance imaging scans and medical assessments. Heritability, that is, the ratio of the additive genetic variance to the total phenotypic variance, was estimated using the twin design. Heritability was high for total WMH volume (0.76), and for periventricular WMH (0.64) and deep WMH (0.77), and varied from 0.18 for the cerebellum to 0.76 for the occipital lobe. The genetic correlation between deep and periventricular WMH regions was 0.85, with one additive genetics factor accounting for most of the shared variance. Heritability was consistently higher in women in the cerebral regions. Heritability in deep but not periventricular WMH declined with age, in particular after the age of 75. WMH have a strong genetic influence but this is not uniform through the brain, being higher for deep than periventricular WMH and in the cerebral regions. The genetic influence is higher in women, and there is an age-related decline, most markedly for deep WMH. The data suggest some heterogeneity in the pathogenesis of WMH for different brain regions and for men and women. © 2016 American Heart Association, Inc.

  1. Cognitive Intraindividual Variability and White Matter Integrity in Aging

    Directory of Open Access Journals (Sweden)

    Nathalie Mella

    2013-01-01

    Full Text Available The intraindividual variability (IIV of cognitive performance has been shown to increase with aging. While brain research has generally focused on mean performance, little is known about neural correlates of cognitive IIV. Nevertheless, some studies suggest that IIV relates more strongly than mean level of performance to the quality of white matter (WM. Our study aims to explore the relation between WM integrity and cognitive IIV by combining functional (fMRI and structural (diffusion tensor imaging, DTI imaging. Twelve young adults (aged 18–30 years and thirteen older adults (61–82 years underwent a battery of neuropsychological tasks, along with fMRI and DTI imaging. Their behavioral data were analyzed and correlated with the imaging data at WM regions of interest defined on the basis of (1 the fMRI-activated areas and (2 the Johns Hopkins University (JHU WM tractography atlas. For both methods, fractional anisotropy, along with the mean, radial, and axial diffusivity parameters, was computed. In accord with previous studies, our results showed that the DTI parameters were more related to IIV than to mean performance. Results also indicated that age differences in the DTI parameters were more pronounced in the regions activated primarily by young adults during a choice reaction-time task than in those also activated in older adults.

  2. Different associations of white matter lesions with depression and cognition

    Directory of Open Access Journals (Sweden)

    Lee Jun-Young

    2012-08-01

    Full Text Available Abstract Background To test the hypothesis that white matter lesions (WML are primarily associated with regional frontal cortical volumes, and to determine the mediating effects of these regional frontal cortices on the associations of WML with depressive symptoms and cognitive dysfunction. Methods Structural brains MRIs were performed on 161 participants: cognitively normal, cognitive impaired but not demented, and demented participants. Lobar WML volumes, regional frontal cortical volumes, depressive symptom severity, and cognitive abilities were measured. Multiple linear regression analyses were used to identify WML volume effects on frontal cortical volume. Structural equation modeling was used to determine the MRI-depression and the MRI-cognition path relationships. Results WML predicted frontal cortical volume, particularly in medial orbirtofrontal cortex, irrespective of age, gender, education, and group status. WML directly predicted depressive score, and this relationship was not mediated by regional frontal cortices. In contrast, the association between WML and cognitive function was indirect and mediated by regional frontal cortices. Conclusions These findings suggest that the neurobiological mechanisms underpinning depressive symptoms and cognitive dysfunction in older adults may differ.

  3. Brain asymmetry in the white matter making and globularity

    Directory of Open Access Journals (Sweden)

    Constantina eTheofanopoulou

    2015-09-01

    Full Text Available Recent studies from the field of language genetics and evolutionary anthropology have put forward the hypothesis that the emergence of our species-specific brain is to be understood not in terms of size, but in light of developmental changes that gave rise to a more globular braincase configuration after the split from Neanderthals-Denisovans. On the grounds that (i white matter myelination is delayed relative to other brain structures and in humans is protracted compared with other primates and (ii neural connectivity is linked genetically to our brain/skull morphology and language-ready brain, I take it that one significant evolutionary change in Homo sapiens’ lineage is the interhemispheric connectivity mediated by the Corpus Callosum. The size, myelination and fiber caliber of the Corpus Callosum presents an anterior-to-posterior increase, in a way that inter-hemispheric connectivity is more prominent in the sensory motor areas, whereas high- order areas are more intra-hemispherically connected. Building on evidence from language-processing studies that account for this asymmetry (‘lateralization’ in terms of brain rhythms, I present an evo-devo hypothesis according to which the myelination of the Corpus Callosum, Brain Asymmetry and Globularity are conjectured to make up the angles of a co-evolutionary triangle that gave rise to our language-ready brain.

  4. Small white matter lesion detection in cerebral small vessel disease

    Science.gov (United States)

    Ghafoorian, Mohsen; Karssemeijer, Nico; van Uden, Inge; de Leeuw, Frank E.; Heskes, Tom; Marchiori, Elena; Platel, Bram

    2015-03-01

    Cerebral small vessel disease (SVD) is a common finding on magnetic resonance images of elderly people. White matter lesions (WML) are important markers for not only the small vessel disease, but also neuro-degenerative diseases including multiple sclerosis, Alzheimer's disease and vascular dementia. Volumetric measurements such as the "total lesion load", have been studied and related to these diseases. With respect to SVD we conjecture that small lesions are important, as they have been observed to grow over time and they form the majority of lesions in number. To study these small lesions they need to be annotated, which is a complex and time-consuming task. Existing (semi) automatic methods have been aimed at volumetric measurements and large lesions, and are not suitable for the detection of small lesions. In this research we established a supervised voxel classification CAD system, optimized and trained to exclusively detect small WMLs. To achieve this, several preprocessing steps were taken, which included a robust standardization of subject intensities to reduce inter-subject intensity variability as much as possible. A number of features that were found to be well identifying small lesions were calculated including multimodal intensities, tissue probabilities, several features for accurate location description, a number of second order derivative features as well as multi-scale annular filter for blobness detection. Only small lesions were used to learn the target concept via Adaboost using random forests as its basic classifiers. Finally the results were evaluated using Free-response receiver operating characteristic.

  5. White matter injury in term newborns with neonatal encephalopathy.

    Science.gov (United States)

    Li, Amanda M; Chau, Vann; Poskitt, Kenneth J; Sargent, Michael A; Lupton, Brian A; Hill, Alan; Roland, Elke; Miller, Steven P

    2009-01-01

    White matter injury (WMI) is the characteristic pattern of brain injury detected on magnetic resonance imaging in the premature newborn. Focal noncystic WMI is increasingly recognized in populations of term newborns. The aim of this study was to describe the occurrence of focal noncystic WMI in a cohort of 48 term newborns with encephalopathy studied with magnetic resonance imaging at 72 +/- 12 h of life, and to identify clinical risk factors for this pattern of injury. Eleven newborns (23%; 95% CI 11-35) were found to have WMI (four minimal, three moderate, and four severe). In 10 of the 11 newborns, the WMI was associated with restricted diffusion on apparent diffusion coefficient maps. An increasing severity of WMI was associated with lower gestational age at birth (p = 0.05), but not lower birth weight. Newborns with WMI had milder encephalopathy and fewer clinical seizures relative to other newborns in the cohort. Other brain injuries were seen in three of the 11 newborns: basal nuclei predominant pattern of injury in one and cortical strokes in two. These findings suggest that WMI in the term newborn is acquired near birth and that the state of brain maturation is an important determinant of this pattern of brain injury.

  6. White matter hyperintensities segmentation: a new semi-automated method

    Directory of Open Access Journals (Sweden)

    Mariangela eIorio

    2013-12-01

    Full Text Available White matter hyperintensities (WMH are brain areas of increased signal on T2-weighted or fluid attenuated inverse recovery magnetic resonance imaging (MRI scans. In this study we present a new semi-automated method to measure WMH load that is based on the segmentation of the intensity histogram of fluid-attenuated inversion recovery images. Thirty patients with Mild Cognitive Impairment with variable WMH load were enrolled. The semi-automated WMH segmentation included: removal of non-brain tissue, spatial normalization, removal of cerebellum and brain stem, spatial filtering, thresholding to segment probable WMH, manual editing for correction of false positives and negatives, generation of WMH map and volumetric estimation of the WMH load. Accuracy was quantitatively evaluated by comparing semi-automated and manual WMH segmentations performed by two independent raters. Differences between the two procedures were assessed using Student’s t tests and similarity was evaluated using linear regression model and Dice Similarity Coefficient (DSC. The volumes of the manual and semi-automated segmentations did not statistically differ (t-value= -1.79, DF=29, p= 0.839 for rater 1; t-value= 1.113, DF=29, p= 0.2749 for rater 2, were highly correlated (R²= 0.921, F (1,29 =155,54, p

  7. Occipital White Matter Tracts in Human and Macaque.

    Science.gov (United States)

    Takemura, Hiromasa; Pestilli, Franco; Weiner, Kevin S; Keliris, Georgios A; Landi, Sofia M; Sliwa, Julia; Ye, Frank Q; Barnett, Michael A; Leopold, David A; Freiwald, Winrich A; Logothetis, Nikos K; Wandell, Brian A

    2017-06-01

    We compare several major white-matter tracts in human and macaque occipital lobe using diffusion magnetic resonance imaging. The comparison suggests similarities but also significant differences in the tracts. There are several apparently homologous tracts in the 2 species, including the vertical occipital fasciculus (VOF), optic radiation, forceps major, and inferior longitudinal fasciculus (ILF). There is one large human tract, the inferior fronto-occipital fasciculus, with no corresponding fasciculus in macaque. We could identify the macaque VOF (mVOF), which has been little studied. Its position is consistent with classical invasive anatomical studies by Wernicke. VOF homology is supported by similarity of the endpoints in V3A and ventral V4 across species. The mVOF fibers intertwine with the dorsal segment of the ILF, but the human VOF appears to be lateral to the ILF. These similarities and differences between the occipital lobe tracts will be useful in establishing which circuitry in the macaque can serve as an accurate model for human visual cortex. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  8. Anatomy and white matter connections of the orbitofrontal gyrus.

    Science.gov (United States)

    Burks, Joshua D; Conner, Andrew K; Bonney, Phillip A; Glenn, Chad A; Baker, Cordell M; Boettcher, Lillian B; Briggs, Robert G; O'Donoghue, Daniel L; Wu, Dee H; Sughrue, Michael E

    2017-09-01

    OBJECTIVE The orbitofrontal cortex (OFC) is understood to have a role in outcome evaluation and risk assessment and is commonly involved with infiltrative tumors. A detailed understanding of the exact location and nature of associated white matter tracts could significantly improve postoperative morbidity related to declining capacity. Through diffusion tensor imaging-based fiber tracking validated by gross anatomical dissection as ground truth, the authors have characterized these connections based on relationships to other well-known structures. METHODS Diffusion imaging from the Human Connectome Project for 10 healthy adult controls was used for tractography analysis. The OFC was evaluated as a whole based on connectivity with other regions. All OFC tracts were mapped in both hemispheres, and a lateralization index was calculated with resultant tract volumes. Ten postmortem dissections were then performed using a modified Klingler technique to demonstrate the location of major tracts. RESULTS The authors identified 3 major connections of the OFC: a bundle to the thalamus and anterior cingulate gyrus, passing inferior to the caudate and medial to the vertical fibers of the thalamic projections; a bundle to the brainstem, traveling lateral to the caudate and medial to the internal capsule; and radiations to the parietal and occipital lobes traveling with the inferior fronto-occipital fasciculus. CONCLUSIONS The OFC is an important center for processing visual, spatial, and emotional information. Subtle differences in executive functioning following surgery for frontal lobe tumors may be better understood in the context of the fiber-bundle anatomy highlighted by this study.

  9. Relationship between progression of brain white matter changes and late-life depression: 3-year results from the LADIS study

    NARCIS (Netherlands)

    Firbank, M.J.; Teodorczuk, A.; van der Flier, W.M.; Gouw, A.A.; Wallin, A.; Erkinjuntti, T.; Inzitari, D.; Wahlund, L.O.; Pantoni, L.; Poggesi, A.; Pracucci, G.; Langhorne, P.; O'Brien, J. T.

    2012-01-01

    Background: Brain white matter changes (WMC) and depressive symptoms are linked, but the directionality of this association remains unclear. Aims: To investigate the relationship between baseline and incident depression and progression of white matter changes. Method: In a longitudinal multicentre

  10. Optimal voxel size for measuring global gray and white matter proton metabolite concentrations using chemical shift imaging

    DEFF Research Database (Denmark)

    Hanson, Lars Peter Grüner; Adalsteinsson, E; Pfefferbaum, A

    2000-01-01

    Quantification of gray and white matter levels of spectroscopically visible metabolites can provide important insights into brain development and pathological conditions. Chemical shift imaging offers a gain in efficiency for estimation of global gray and white matter metabolite concentrations co...

  11. The Classical Pathways of Occipital Lobe Epileptic Propagation Revised in the Light of White Matter Dissection.

    Science.gov (United States)

    Latini, Francesco; Hjortberg, Mats; Aldskogius, Håkan; Ryttlefors, Mats

    2015-01-01

    The clinical evidences of variable epileptic propagation in occipital lobe epilepsy (OLE) have been demonstrated by several studies. However the exact localization of the epileptic focus sometimes represents a problem because of the rapid propagation to frontal, parietal, or temporal regions. Each white matter pathway close to the supposed initial focus can lead the propagation towards a specific direction, explaining the variable semiology of these rare epilepsy syndromes. Some new insights in occipital white matter anatomy are herein described by means of white matter dissection and compared to the classical epileptic patterns, mostly based on the central position of the primary visual cortex. The dissections showed a complex white matter architecture composed by vertical and longitudinal bundles, which are closely interconnected and segregated and are able to support specific high order functions with parallel bidirectional propagation of the electric signal. The same sublobar lesions may hyperactivate different white matter bundles reemphasizing the importance of the ictal semiology as a specific clinical demonstration of the subcortical networks recruited. Merging semiology, white matter anatomy, and electrophysiology may lead us to a better understanding of these complex syndromes and tailored therapeutic options based on individual white matter connectivity.

  12. Whole brain white matter changes revealed by multiple diffusion metrics in multiple sclerosis: A TBSS study

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yaou, E-mail: asiaeurope80@gmail.com [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Duan, Yunyun, E-mail: xiaoyun81.love@163.com [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); He, Yong, E-mail: yong.h.he@gmail.com [State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875 (China); Yu, Chunshui, E-mail: csyuster@gmail.com [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Wang, Jun, E-mail: jun_wang@bnu.edu.cn [State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875 (China); Huang, Jing, E-mail: sainthj@126.com [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Ye, Jing, E-mail: jingye.2007@yahoo.com.cn [Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Parizel, Paul M., E-mail: paul.parizel@ua.ac.be [Department of Radiology, Antwerp University Hospital and University of Antwerp, Wilrijkstraat 10, 2650 Edegem, 8 Belgium (Belgium); Li, Kuncheng, E-mail: kunchengli55@gmail.com [Department of Radiology, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Shu, Ni, E-mail: nshu55@gmail.com [State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875 (China)

    2012-10-15

    Objective: To investigate whole brain white matter changes in multiple sclerosis (MS) by multiple diffusion indices, we examined patients with diffusion tensor imaging and utilized tract-based spatial statistics (TBSS) method to analyze the data. Methods: Forty-one relapsing-remitting multiple sclerosis (RRMS) patients and 41 age- and gender-matched normal controls were included in this study. Diffusion weighted images were acquired by employing a single-shot echo planar imaging sequence on a 1.5 T MR scanner. Voxel-wise analyses of multiple diffusion metrics, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) were performed with TBSS. Results: The MS patients had significantly decreased FA (9.11%), increased MD (8.26%), AD (3.48%) and RD (13.17%) in their white matter skeletons compared with the controls. Through TBSS analyses, we found abnormal diffusion changes in widespread white matter regions in MS patients. Specifically, decreased FA, increased MD and increased RD were involved in whole-brain white matter, while several regions exhibited increased AD. Furthermore, white matter regions with significant correlations between the diffusion metrics and the clinical variables (the EDSS scores, disease durations and white matter lesion loads) in MS patients were identified. Conclusion: Widespread white matter abnormalities were observed in MS patients revealed by multiple diffusion metrics. The diffusion changes and correlations with clinical variables were mainly attributed to increased RD, implying the predominant role of RD in reflecting the subtle pathological changes in MS.

  13. Whole brain white matter changes revealed by multiple diffusion metrics in multiple sclerosis: A TBSS study

    International Nuclear Information System (INIS)

    Liu, Yaou; Duan, Yunyun; He, Yong; Yu, Chunshui; Wang, Jun; Huang, Jing; Ye, Jing; Parizel, Paul M.; Li, Kuncheng; Shu, Ni

    2012-01-01

    Objective: To investigate whole brain white matter changes in multiple sclerosis (MS) by multiple diffusion indices, we examined patients with diffusion tensor imaging and utilized tract-based spatial statistics (TBSS) method to analyze the data. Methods: Forty-one relapsing-remitting multiple sclerosis (RRMS) patients and 41 age- and gender-matched normal controls were included in this study. Diffusion weighted images were acquired by employing a single-shot echo planar imaging sequence on a 1.5 T MR scanner. Voxel-wise analyses of multiple diffusion metrics, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) were performed with TBSS. Results: The MS patients had significantly decreased FA (9.11%), increased MD (8.26%), AD (3.48%) and RD (13.17%) in their white matter skeletons compared with the controls. Through TBSS analyses, we found abnormal diffusion changes in widespread white matter regions in MS patients. Specifically, decreased FA, increased MD and increased RD were involved in whole-brain white matter, while several regions exhibited increased AD. Furthermore, white matter regions with significant correlations between the diffusion metrics and the clinical variables (the EDSS scores, disease durations and white matter lesion loads) in MS patients were identified. Conclusion: Widespread white matter abnormalities were observed in MS patients revealed by multiple diffusion metrics. The diffusion changes and correlations with clinical variables were mainly attributed to increased RD, implying the predominant role of RD in reflecting the subtle pathological changes in MS

  14. A voxel-based diffusion tensor imaging study of white matter in bipolar disorder.

    Science.gov (United States)

    Mahon, Katie; Wu, Jinghui; Malhotra, Anil K; Burdick, Katherine E; DeRosse, Pamela; Ardekani, Babak A; Szeszko, Philip R

    2009-05-01

    There is evidence from post-mortem and magnetic resonance imaging studies that hyperintensities, oligodendroglial abnormalities, and gross white matter volumetric alterations are involved in the pathophysiology of bipolar disorder. There is also functional imaging evidence for a defect in frontal cortico-subcortical pathways in bipolar disorder, but the white matter comprising these pathways has not been well investigated. Few studies have investigated white matter integrity in patients with bipolar disorder compared to healthy volunteers and the majority of studies have used manual region-of-interest approaches. In this study, we compared fractional anisotropy (FA) values between 30 patients with bipolar disorder and 38 healthy volunteers in the brain white matter using a voxelwise analysis following intersubject registration to Talairach space. Compared to healthy volunteers, patients demonstrated significantly (p or =50) higher FA within the right and left frontal white matter and lower FA within the left cerebellar white matter. Examination of individual eigenvalues indicated that group differences in both axial diffusivity and radial diffusivity contributed to abnormal FA within these regions. Tractography was performed in template space on averaged diffusion tensor imaging data from all individuals. Extraction of bundles passing through the clusters that differed significantly between groups suggested that white matter abnormalities along the pontine crossing tract, corticospinal/corticopontine tracts, and thalamic radiation fibers may be involved in the pathogenesis of bipolar disorder. Our findings are consistent with models of bipolar disorder that implicate dysregulation of cortico-subcortical and cerebellar regions in the disorder and may have relevance for phenomenology.

  15. Raymond de Vieussens and his contribution to the study of white matter anatomy: historical vignette.

    Science.gov (United States)

    Vergani, Francesco; Morris, Christopher M; Mitchell, Patrick; Duffau, Hugues

    2012-12-01

    In recent years, there has been a renewed interest in the study of white matter anatomy, both with the use of postmortem dissections and diffusion tensor imaging tractography. One of the precursors in the study of white matter anatomy was Raymond de Vieussens (1641-1716), a French anatomist born in Le Vigan. He studied medicine at the University of Montpellier in southern France, one of the most ancient and lively schools of medicine in Europe. In 1684 Vieussens published his masterpiece, the Neurographia Universalis, which is still considered one of the most complete and accurate descriptions of the nervous system provided in the 17th century. He described the white matter of the centrum ovale and was the first to demonstrate the continuity of the white matter fibers from the centrum ovale to the brainstem. He also described the dentate nuclei, the pyramids, and the olivary nuclei. According to the theory of Galen, Vieussens considered that the function of the white matter was to convey the "animal spirit" from the centrum ovale to the spinal cord. Although neglected, Vieussens' contribution to the study of white matter is relevant. His pioneering work showed that the white matter is not a homogeneous substance, but rather a complex structure rich in fibers that are interconnected with different parts of the brain. These initial results paved the way to advancements observed in later centuries that eventually led to modern hodology.

  16. The Classical Pathways of Occipital Lobe Epileptic Propagation Revised in the Light of White Matter Dissection

    Science.gov (United States)

    Latini, Francesco; Hjortberg, Mats; Aldskogius, Håkan; Ryttlefors, Mats

    2015-01-01

    The clinical evidences of variable epileptic propagation in occipital lobe epilepsy (OLE) have been demonstrated by several studies. However the exact localization of the epileptic focus sometimes represents a problem because of the rapid propagation to frontal, parietal, or temporal regions. Each white matter pathway close to the supposed initial focus can lead the propagation towards a specific direction, explaining the variable semiology of these rare epilepsy syndromes. Some new insights in occipital white matter anatomy are herein described by means of white matter dissection and compared to the classical epileptic patterns, mostly based on the central position of the primary visual cortex. The dissections showed a complex white matter architecture composed by vertical and longitudinal bundles, which are closely interconnected and segregated and are able to support specific high order functions with parallel bidirectional propagation of the electric signal. The same sublobar lesions may hyperactivate different white matter bundles reemphasizing the importance of the ictal semiology as a specific clinical demonstration of the subcortical networks recruited. Merging semiology, white matter anatomy, and electrophysiology may lead us to a better understanding of these complex syndromes and tailored therapeutic options based on individual white matter connectivity. PMID:26063964

  17. Damage to white matter bottlenecks contributes to language impairments after left hemispheric stroke

    Directory of Open Access Journals (Sweden)

    Joseph C. Griffis

    2017-01-01

    Full Text Available Damage to the white matter underlying the left posterior temporal lobe leads to deficits in multiple language functions. The posterior temporal white matter may correspond to a bottleneck where both dorsal and ventral language pathways are vulnerable to simultaneous damage. Damage to a second putative white matter bottleneck in the left deep prefrontal white matter involving projections associated with ventral language pathways and thalamo-cortical projections has recently been proposed as a source of semantic deficits after stroke. Here, we first used white matter atlases to identify the previously described white matter bottlenecks in the posterior temporal and deep prefrontal white matter. We then assessed the effects of damage to each region on measures of verbal fluency, picture naming, and auditory semantic decision-making in 43 chronic left hemispheric stroke patients. Damage to the posterior temporal bottleneck predicted deficits on all tasks, while damage to the anterior bottleneck only significantly predicted deficits in verbal fluency. Importantly, the effects of damage to the bottleneck regions were not attributable to lesion volume, lesion loads on the tracts traversing the bottlenecks, or damage to nearby cortical language areas. Multivariate lesion-symptom mapping revealed additional lesion predictors of deficits. Post-hoc fiber tracking of the peak white matter lesion predictors using a publicly available tractography atlas revealed evidence consistent with the results of the bottleneck analyses. Together, our results provide support for the proposal that spatially specific white matter damage affecting bottleneck regions, particularly in the posterior temporal lobe, contributes to chronic language deficits after left hemispheric stroke. This may reflect the simultaneous disruption of signaling in dorsal and ventral language processing streams.

  18. Experimental focal neocortical epilepsy is associated with reduced white matter volume growth : results from multiparametric MRI analysis

    NARCIS (Netherlands)

    Otte, Wim; van Meer, Maurits P A; van der Marel, Kajo; Zwartbol, René; Viergever, Max A.; Braun, Kees P J; Dijkhuizen, Rick M.

    2015-01-01

    Focal epilepsy has recently been associated with remote white matter damage, including reduced white matter volume. Longitudinal assessment of these white matter changes, in relation to functional mechanisms and consequences, may be ideally done by in vivo neuroimaging in well-controlled

  19. Progressive white-matter disease with primary cerebellar involvement: a separate entity?

    Energy Technology Data Exchange (ETDEWEB)

    Yalcinkaya, C. [Division of Child Neurology, Department of Neurology, Cerrahpasa Medical Faculty, Istanbul University, Istanbul (Turkey); Arslanoglu, I. [Division of Endocrinology, Department of Paediatrics, Goeztepe Hospital, Istanbul (Turkey); Islak, C. [Division of Neuroradiology, Department of Radiology, Cerrahpasa Medical Faculty, Istanbul University, Istanbul (Turkey); Aydin, A. [Division of Metabolic Disease, Department of Paediatrics, Cerrahpasa Medical Faculty, Istanbul University, Istanbul (Turkey); Boltshauser, E. [Division of Paediatric Neurology, University Children' s Hospital, Steinwiesstrasse 75, 8032 Zuerich (Switzerland)

    2002-09-01

    Although its metabolic basis has not yet been clarified, we report a progressive white-matter disease in a Turkish girl, starting in the cerebellum and spreading to supratentorial white matter. The onset was at the age of 2.5 years with diabetes insipidus, followed by ataxia and pyramidal signs resulting in loss of walking. Aqueduct stenosis was first recognised at the age of 8 years. To our knowledge, this MRI and clinical pattern does not correspond to a recognised, well-defined white-matter disease and may indicate a separate entity. (orig.)

  20. Progressive white-matter disease with primary cerebellar involvement: a separate entity?

    International Nuclear Information System (INIS)

    Yalcinkaya, C.; Arslanoglu, I.; Islak, C.; Aydin, A.; Boltshauser, E.

    2002-01-01

    Although its metabolic basis has not yet been clarified, we report a progressive white-matter disease in a Turkish girl, starting in the cerebellum and spreading to supratentorial white matter. The onset was at the age of 2.5 years with diabetes insipidus, followed by ataxia and pyramidal signs resulting in loss of walking. Aqueduct stenosis was first recognised at the age of 8 years. To our knowledge, this MRI and clinical pattern does not correspond to a recognised, well-defined white-matter disease and may indicate a separate entity. (orig.)

  1. Diffusion-weighted magnetic resonance imaging of cerebral white matter development

    International Nuclear Information System (INIS)

    Prayer, Daniela.; Prayer, Lucas

    2003-01-01

    Diffusion-weighted magnetic resonance imaging (DWI) has become a sensitive tool to monitor white matter development. Different applications of diffusion-weighted techniques provide information about premyelinating, myelinating, and postmyelinating states of white matter maturation. Mirroring maturational processes on the cellular level, DWI has to be regarded as a morphological method as well as a functional instrument, giving insight into molecular processes during the formation of axons and myelin sheets and into the steric arrangement of white matter tracts the formation of which is strongly influenced by their function

  2. Diffusion-weighted magnetic resonance imaging of cerebral white matter development

    Energy Technology Data Exchange (ETDEWEB)

    Prayer, Daniela. E-mail: daniela.prayer@univie.ac.at; Prayer, Lucas

    2003-03-01

    Diffusion-weighted magnetic resonance imaging (DWI) has become a sensitive tool to monitor white matter development. Different applications of diffusion-weighted techniques provide information about premyelinating, myelinating, and postmyelinating states of white matter maturation. Mirroring maturational processes on the cellular level, DWI has to be regarded as a morphological method as well as a functional instrument, giving insight into molecular processes during the formation of axons and myelin sheets and into the steric arrangement of white matter tracts the formation of which is strongly influenced by their function.

  3. The role of white matter lesions in cognitive impairment of vascular origin

    International Nuclear Information System (INIS)

    Kazakov, D.

    2003-01-01

    Abnormalities involving the cerebral white matter, in particular the centrum semiovale, are a subject of great current interest. Partly this is because modern neuroimaging methods detect white matter changes with increasing frequency in persons older than 60 years and also because these abnormalities may be associated with specific neuro behavioral deficits, including cognitive impairment. The significance of these changes, as well as their pathophysiological background is incompletely understood. The aim of this paper is to critically review the existing knowledge about the role of the white matter lesions, based on the critical analysis of over 100 publications (most appearing in the last decade). (author)

  4. White matter mapping by DTI-based tractography for neurosurgery

    International Nuclear Information System (INIS)

    Kamada, Kyousuke

    2009-01-01

    To validate the corticospinal tract (CST) and arcuate fasciculus (AF) illustrated by diffusion tensor imaging (DTI), we used CST- and AF-tractography integrated neuronavigation and monopolar and bipolar direct fiber stimulation. Forty seven patients with brain lesions adjacent to the CST and AF were studied. During lesion resection, direct fiber stimulation was applied to the CST and AF to elicit motor responses (fiber-motor evoked potential (MEP)) and the impairment of language-related functions to identify the CST and AF. The minimum distance between the resection border and illustrated CST was measured on postoperative images. Direct fiber stimulation demonstrated that CST- and AF-tractography accurately reflected anatomical CST functioning. The cortical stimulation to the gyrus, including the language-functional MRI (fMRI) activation, evoked speech arrest, while the subcortical stimulation close to the AF reproducibly caused 'paranomia' without speech arrest. There were strong correlations between stimulus intensity for the fiber-MEP and the distance between eloquent fibers and the stimulus points. The convergent calculation formulated 1.8 mA as the electrical threshold of CST for the fiber-MEP, which was much smaller than that of the hand motor area. Validated tractography demonstrated the mean distance and intersection angle between CST and AF were 5 mm and 107 deg, respectively. In addition, the anisotropic diffusion-weighted image (ADWI) and CST-tractography clearly indicated the locations of the primary motor area (PMA) and the central sulcus and well reflected the anatomical characteristics of the corticospinal tract in the human brain. DTI-based tractography is a reliable way to map the white matter connections in the entire brain in clinical and basic neuroscience. By combining these techniques, investigating the cortico-subcortical connections in the human central nervous system could contribute to elucidating the neural networks of the human brain and

  5. White matter mapping by DTI-based tractography for neurosurgery

    International Nuclear Information System (INIS)

    Kamada, Kyousuke

    2011-01-01

    The purpose of this study was to validate the corticospinal tract (CST) and arcuate fasciculus (AF) illustrated by diffusion tensor imaging (DTI), we used CST- and AF-tractography integrated neuronavigation and monopolar and bipolar direct fiber stimulation. Forty seven patients with brain lesions adjacent to the CST and AF were studied. During lesion resection, direct fiber stimulation was applied to the CST and AF to elicit motor responses (fiber-MEP) and the impairment of language-related functions to identify the CST and AF. The minimum distance between the resection border and illustrated CST was measured on postoperative images. Direct fiber stimulation demonstrated that CST- and AF-tractography accurately reflected anatomical CST functioning. The cortical stimulation to the gyrus, including the language-fMRI activation, evoked speech arrest, while the subcortical stimulation close to the AF reproducibly caused 'paranomia' without speech arrest. There were strong correlations between stimulus intensity for the fiber-MEP and the distance between eloquent fibers and the stimulus points. The convergent calculation formulated 1.8 mA as the electrical threshold of CST for the fiber-MEP, which was much smaller than that of the hand motor area. Validated tractography demonstrated the mean distance and intersection angle between CST and AF were 5 mm and 107 deg, respectively. In addition, the anisotropic diffusion-weighted image (ADWI) and CST-tractography clearly indicated the locations of the primary motor area (PMA) and the central sulcus and well reflected the anatomical characteristics of the corticospinal tract in the human brain. DTI-based tractography is a reliable way to map the white matter connections in the entire brain in clinical and basic neuroscience. By combining these techniques, investigating the cortico-subcortical connections in the human central nervous system could contribute to elucidating the neural networks of the human brain and shed light

  6. White matter damage impairs access to consciousness in multiple sclerosis.

    Science.gov (United States)

    Reuter, Françoise; Del Cul, Antoine; Malikova, Irina; Naccache, Lionel; Confort-Gouny, Sylviane; Cohen, Laurent; Cherif, André Ali; Cozzone, Patrick J; Pelletier, Jean; Ranjeva, Jean-Philippe; Dehaene, Stanislas; Audoin, Bertrand

    2009-01-15

    Global neuronal workspace theory predicts that damage to long-distance white matter (WM) tracts should impair access to consciousness during the perception of brief stimuli. To address this issue, we studied visual backward masking in 18 patients at the very first clinical stage of multiple sclerosis (MS), a neurological disease characterized by extensive WM damage, and in 18 matched healthy subjects. In our masking paradigm, the visibility of a digit stimulus increases non-linearly as a function of the interval duration between this target and a subsequent mask. In order to characterize quantitatively, for each subject, the transition between non-conscious and conscious perception of the stimulus, we used non-linear regression to fit a sigmoid curve to objective performance and subjective visibility reports as a function of target-mask delay. The delay corresponding to the inflexion point of the sigmoid, where visibility suddenly increases, was termed the "non-linear transition threshold" and used as a summary measure of masking efficiency. Objective and subjective non-linear transition thresholds were highly correlated across subjects in both groups, and were higher in patients compared to controls. In patients, variations in the non-linear transition threshold were inversely correlated to the Magnetization transfer ratio (MTR) values inside the right dorsolateral prefrontal WM, the right occipito-frontal fasciculus and the left cerebellum. This study provides clinical evidence of a relationship between impairments of conscious access and integrity of large WM bundles, particularly involving prefrontal cortex, as predicted by global neuronal workspace theory.

  7. White matter lesions of the aging brain visualized on MRI

    International Nuclear Information System (INIS)

    Tomura, Noriaki; Shindou, Masaaki; Hashimoto, Manabu; Kato, Toshio; Monma, Keiji; Segawa, Yasuhiko.

    1990-01-01

    The purpose of this report is to study the relationship between the severity of the white matter lesions (WMLs) and aging. We reviewed 215 subjects (11-88 years of age) referred for MR imaging performed between June 1988 and August 1989 on a 0.5T superconducting MR imager. The spin echo technique of image acquisition was used, with TR 1800 ms and TE 120 ms. All subjects were free from neurological abnormalities. The patterns of MR imaging of the incidental WMLs were divided into four grades; grades 0-3 (grade 0, no lesions; grade 1, lesions confined to one lobe; grade 2, lesions beyond one lobe; grade 3, confluent periventricular lesions). We investigated the relationships among the prevalence of WMLs, the grading of WMLs, age, and hypertension. Furthermore, we analyzed the grading of WMLs in relation to the degree of brain atrophy (bicaudate index) and the prevalence of basal ganglionic lesions. The mean age of grade 0 (n=90), grade 1 (n=36), grade 2 (n=58) and grade 3 (n=31) was 43.4±13.2, 57.3±7.3, 63.5±10.8 and 71.6±8.5. The statistical difference of age between grade 0 and 1 (p 160 mmHg) showed higher grading of WMLs than other subjects. There was a statistical difference in the bicaudate index between grade 0 and 2 (p<0.001), and grade 0 and 3 (p<0.001). Of the 89 subjects of grade 2 or 3, 47 (53%) had basal ganglionic and/or thalamic lesions. It was confirmed that WMLs of neurologically healthy subjects significantly correlated with aging. In addition, hypertension accelerated WMLs. (author)

  8. Neurons in the white matter of the adult human neocortex

    Directory of Open Access Journals (Sweden)

    M Luisa Suarez-Sola

    2009-06-01

    Full Text Available The white matter (WM of the adult human neocortex contains the so-called “interstitial neurons”. They are most numerous in the superficial WM underlying the cortical gyri, and decrease in density toward the deep WM. They are morphologically heterogeneous. A subgroup of interstitial neurons display pyramidal-cell like morphologies, characterized by a polarized dendritic tree with a dominant apical dendrite, and covered with a variable number of dendritic spines. In addition, a large contingent of interstitial neurons can be classified as interneurons based on their neurochemical profile as well as on morphological criteria. WM- interneurons have multipolar or bipolar shapes and express GABA and a variety of other neuronal markers, such as calbindin and calretinin, the extracellular matrix protein reelin, or neuropeptide Y, somatostatin, and nitric oxide synthase. The heterogeneity of interstitial neurons may be relevant for the pathogenesis of Alzheimer disease and schizophrenia. Interstitial neurons are most prominent in human brain, and only rudimentary in the brain of non-primate mammals. These evolutionary differences have precluded adequate experimental work on this cell population, which is usually considered as a relict of the subplate, a transient compartment proper of development and without a known function in the adult brain. The primate-specific prominence of the subplate in late fetal stages points to an important role in the establishment of interstitial neurons. Neurons in the adult WM may be actively involved in coordinating inter-areal connectivity and regulation of blood flow. Further studies in primates will be needed to elucidate the developmental history, adult components and activities of this large neuronal system.

  9. Initial Incidence of White Matter Hyperintensities on MRI in Astronauts

    Science.gov (United States)

    Norcross, Jason; Sherman, Paul; McGuire, Steve; Kochunov, Peter

    2016-01-01

    Introduction: Previous literature has described the increase in white matter hyperintensity (WMH) burden associated with hypobaric exposure in the U-2 and altitude chamber operating personnel. Although astronauts have similar hypobaric exposure pressures to the U2 pilot population, astronauts have far fewer exposures and each exposure would be associated with a much lower level of decompression stress due to rigorous countermeasures to prevent decompression sickness. Therefore, we postulated that the WMH burden in the astronaut population would be less than in U2 pilots. Methods: Twenty-one post-flight de-identified astronaut MRIs (5 mm slice thickness FLAIR sequences) were evaluated for WMH count and volume. The only additional data provided was an age range of the astronauts (43-57) and if they had ever performed an EVA (13 yes, 8 no). Results: WMH count in these 21 astronaut MRI was 21.0 +/- 24.8 (mean+/- SD) and volume was 0.382 +/- 0.602 ml, which was significantly higher than previously published results for the U2 pilots. No significant differences between EVA and no EVA groups existed. Age range of astronaut population is not directly comparable to the U2 population. Discussion: With significantly less frequent (sometimes none) and less stressful hypobaric exposures, yet a much higher incidence of increased WMH, this indicates the possibility of additional mechanisms beyond hypobaric exposure. This increase unlikely to be attributable just to the differences in age between astronauts and U2 pilots. Forward work includes continuing review of post-flight MRI and evaluation of pre to post flight MRI changes if available. Data mining for potential WMH risk factors includes collection of age, sex, spaceflight experience, EVA hours, other hypobaric exposures, hyperoxic exposures, radiation, high performance aircraft experience and past medical history. Finally, neurocognitive and vision/eye results will be evaluated for any evidence of impairment linked to

  10. Individual white matter fractional anisotropy analysis on patients with MRI negative partial epilepsy.

    Science.gov (United States)

    Duning, Thomas; Kellinghaus, Christoph; Mohammadi, Siawoosh; Schiffbauer, Hagen; Keller, Simon; Ringelstein, E Bernd; Knecht, Stefan; Deppe, Michael

    2010-02-01

    Conventional structural MRI fails to identify a cerebral lesion in 25% of patients with cryptogenic partial epilepsy (CPE). Diffusion tensor imaging is an MRI technique sensitive to microstructural abnormalities of cerebral white matter (WM) by quantification of fractional anisotropy (FA). The objectives of the present study were to identify focal FA abnormalities in patients with CPE who were deemed MRI negative during routine presurgical evaluation. Diffusion tensor imaging at 3 T was performed in 12 patients with CPE and normal conventional MRI and in 67 age matched healthy volunteers. WM integrity was compared between groups on the basis of automated voxel-wise statistics of FA maps using an analysis of covariance. Volumetric measurements from high resolution T1-weighted images were also performed. Significant FA reductions in WM regions encompassing diffuse areas of the brain were observed when all patients as a group were compared with controls. On an individual basis, voxel based analyses revealed widespread symmetrical FA reduction in CPE patients. Furthermore, asymmetrical temporal lobe FA reduction was consistently ipsilateral to the electroclinical focus. No significant correlations were found between FA alterations and clinical data. There were no differences in brain volumes of CPE patients compared with controls. Despite normal conventional MRI, WM integrity abnormalities in CPE patients extend far beyond the epileptogenic zone. Given that unilateral temporal lobe FA abnormalities were consistently observed ipsilateral to the seizure focus, analysis of temporal FA may provide an informative in vivo investigation into the localisation of the epileptogenic zone in MRI negative patients.

  11. Plasma DNA Mediate Autonomic Dysfunctions and White Matter Injuries in Patients with Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Meng-Hsiang Chen

    2017-01-01

    Full Text Available Background. Cardiovascular autonomic dysfunction is well known in Parkinson’s disease (PD presentation and it produces hypoperfusion of vital organs. The association between cardiovascular autonomic dysfunction and oxidative stress was examined in previous animal models. Oxidative stress and neuroinflammation were thought to have roles in PD pathogenesis. Owing to the relative low intrinsic antioxidative properties, brain white matter (WM is vulnerable to the oxidative stress. This study is conducted to examine possible relationships by using a hypothesis-driven mediation model. Methods. Twenty-nine patients with PD and 26 healthy controls participated in this study, with complete examinations of cardiac autonomic parameters, plasma DNA level, and WM integrity. A single-level three-variable mediation model was used to investigate the possible relationships. Results. The elevated serum oxidative stress biomarkers include plasma nuclear DNA and mitochondrial DNA, and poorer cardiac autonomic parameters and multiple regional microstructural WM changes are demonstrated. Further mediation analysis shows that plasma nuclear DNA served as the mediators between poorer baroreflex sensitivity and mean diffusivity changes in cingulum. Conclusions. These results provide a possible pathophysiology for how the poor baroreflex sensitivity and higher oxidative stress adversely impacted the WM integrity. This model could provide us with a piece of the puzzle of the entire PD pathogenesis.

  12. Abnormal white matter structural connectivity in adults with obsessive-compulsive disorder.

    Science.gov (United States)

    Gan, J; Zhong, M; Fan, J; Liu, W; Niu, C; Cai, S; Zou, L; Wang, Ya; Wang, Yi; Tan, C; Chan, R C K; Zhu, X

    2017-03-14

    Obsessive-compulsive disorder (OCD) is a complex and severe psychiatric disorder whose pathogenesis is not fully understood. Recent studies have shown white matter (WM) alterations in adults with OCD, but the results have been inconsistent. The present study investigated WM structure in OCD patients with the hypothesis that large-scale brain networks may be disrupted in OCD. A total of 24 patients with OCD and 23 healthy controls (HCs) were scanned with diffusion tensor imaging. A tract-based spatial statistics (TBSS) approach was used to detect differences across the whole brain in patients with OCD vs HCs; post hoc fiber tractography was applied to characterize developmental differences between the two groups. Relative to HCs, patients with OCD had lower fractional anisotropy (FA) values in the corpus callosum (CC), left anterior corona radiata (ACR), left superior corona radiata (SCR) and left superior longitudinal fasciculus (SLF), and higher radial diffusivity in the genu and body of CC. Among the TBSS de-projected region of interest results, compared with HCs, patients with OCD showed lower of the mean FA values of fiber bundles passing though the SLF, and shorter lengths of ACR, SCR and CC. In conclusion, this study provides novel evidence of widespread microstructural alterations in OCD and suggests that OCD may involve abnormalities affecting a broader network of regions than commonly believed.

  13. Changes in Parahippocampal White Matter Integrity in Amnestic Mild Cognitive Impairment: A Diffusion Tensor Imaging Study

    Directory of Open Access Journals (Sweden)

    E. J. Rogalski

    2009-01-01

    Full Text Available In the present study, changes in the parahippocampal white matter (PWM, in the region that includes the perforant path, were investigated, in vivo, in 14 individuals with amnestic mild cognitive impairment (aMCI compared to 14 elderly controls with no cognitive impairment (NCI. For this purpose, (1 volumetry; (2 diffusion tensor imaging (DTI derived measures of mean diffusivity (MD and fractional anisotropy (FA; and (3 tractography were used. In addition, regression models were utilized to examine the association of PWM measurements with memory decline. The results from this study confirm previous findings in our laboratory and others, showing that compared to controls, individuals with aMCI have PWM volume loss. In addition to volume reduction, participants with aMCI demonstrated a significant increase in MD, but no difference in FA, both in the PWM region and in fibers modeled to pass through the PWM region. Further, the DTI metric of MD was associated with declarative memory performance, suggesting it may be a sensitive marker for memory dysfunction. These results indicate that there is general tissue loss and degradation (decreased volume; increased MD in individuals with aMCI compared to older people with normal cognitive function. However, the microstructural organization of remaining fibers, as determined by measures of anisotropic diffusion, is not significantly different from that of controls.

  14. Microstructures and formation mechanism of hypoeutectic white cast iron by isothermal electromagnetic rheocast process

    Directory of Open Access Journals (Sweden)

    Zhang Wanning

    2010-05-01

    Full Text Available An investigation was made on the evolution of microstructures of hypoeutectic white cast iron slurry containing 2.5wt.%C and 1.8wt.%Si produced by rheocasting in which the solidifying alloy was vigorously agitated by electromagnetic stirrer during isothermal cooling processes. The results indicated that under the proper agitating temperatures and speeds applied, the dendrite structures in white cast iron slurry were gradually evolved into spherical structures during a certain agitating time. It also revealed that the bent dendrites were formed by either convection force or by the growth of the dendrites themselves in the bending direction; then, as they were in solidifying, they were gradually being alternated into separated particles and into more spherical structures at the end of the isothermal cooling process. Especially, the dendrites were granulated as the bending process proceeding, which suggested that they were caused by unwanted elements such as sulfur and phosphor usually contained in engineering cast iron. Convective flow of the melt caused corrosion on the dendritic segments where they were weaker in strength and lower in melting temperature because of higher concentration of sulfur or phosphor. And the granulation process for such dendrites formed in the melt became possible under the condition. Certainly, dendrite fragments are another factors considerable to function for spherical particles formation. A new mechanism, regarding to the rheocast structure formation of white cast iron, was suggested based on the structural evolution observed in the study.

  15. MRI of white matter changes in the Sjoegren-Larsson syndrome

    International Nuclear Information System (INIS)

    Hussain, M.Z.; Oba, H.; Ohtomo, K.; Aihara, M.; Hayashibe, H.; Nakazawa, S.; Uchiyama, G.

    1995-01-01

    We report a case of Sjoegren-Larsson syndrome with spastic diplegia and conduction aphasia. MRI demonstrated the white matter changes deep in the cerebral hemispheres. We analyse the MRI findings and compare the results with neuropsychological signs. (orig.)

  16. MRI of white matter changes in the Sjoegren-Larsson syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, M.Z. [Dept. of Radiology, Yamanashi Medical Coll., Yamanashi (Japan); Oba, H. [Dept. of Radiology, Yamanashi Medical Coll., Yamanashi (Japan); Ohtomo, K. [Dept. of Radiology, Yamanashi Medical Coll., Yamanashi (Japan); Aihara, M. [Dept. of Paediatrics, Yamanashi Medical Coll., Tamahocho, Yamanashi (Japan); Hayashibe, H. [Dept. of Paediatrics, Yamanashi Medical Coll., Tamahocho, Yamanashi (Japan); Nakazawa, S. [Dept. of Paediatrics, Yamanashi Medical Coll., Tamahocho, Yamanashi (Japan); Uchiyama, G. [Dept. of Radiology, Yamanashi Medical Coll., Yamanashi (Japan)

    1995-10-01

    We report a case of Sjoegren-Larsson syndrome with spastic diplegia and conduction aphasia. MRI demonstrated the white matter changes deep in the cerebral hemispheres. We analyse the MRI findings and compare the results with neuropsychological signs. (orig.)

  17. Broad spectrum of neuropsychiatric phenotypes associated with white matter disease in PTEN hamartoma tumor syndrome.

    Science.gov (United States)

    Balci, Tugce B; Davila, Jorge; Lewis, Denice; Boafo, Addo; Sell, Erick; Richer, Julie; Nikkel, Sarah M; Armour, Christine M; Tomiak, Eva; Lines, Matthew A; Sawyer, Sarah L

    2018-01-01

    White matter lesions have been described in patients with PTEN hamartoma tumor syndrome (PHTS). How these lesions correlate with the neurocognitive features associated with PTEN mutations, such as autism spectrum disorder (ASD) or developmental delay, has not been well established. We report nine patients with PTEN mutations and white matter changes on brain magnetic resonance imaging (MRI), eight of whom were referred for reasons other than developmental delay or ASD. Their clinical presentations ranged from asymptomatic macrocephaly with normal development/intellect, to obsessive compulsive disorder, and debilitating neurological disease. To our knowledge, this report constitutes the first detailed description of PTEN-related white matter changes in adult patients and in children with normal development and intelligence. We present a detailed assessment of the neuropsychological phenotype of our patients and discuss the relationship between the wide array of neuropsychiatric features and observed white matter findings in the context of these individuals. © 2017 Wiley Periodicals, Inc.

  18. Changes in functional organization and white matter integrity in the connectome in Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Sule Tinaz

    2017-01-01

    Our results suggest that despite subtle white matter connectivity changes, the overall structural organization of the PD connectome remains robust at relatively early disease stages. However, there is a breakdown in the functional modular organization of the PD connectome.

  19. White Matter Hyperintensities and Cognitive Impairment During Electroconvulsive Therapy in Severely Depressed Elderly Patients

    NARCIS (Netherlands)

    Oudega, M.L.; van Exel, E.; Wattjes, M.P.; Comijs, H.C.; Scheltens, P.; Barkhof, F.; Eikelenboom, P.; Craen, A.J.M.; Beekman, A.T.F.; Stek, M.L.

    2014-01-01

    Objective: Transient cognitive impairment during electroconvulsive therapy (ECT) can be a reason to discontinue ECT in depressed elderly patients. We hypothesized that both white matter hyperintensities and medial temporal lobe atrophy contribute to transient cognitive impairment during ECT.

  20. White Matter Hyperintensities on MRI in High-Altitude U-2 Pilots

    Science.gov (United States)

    2013-08-19

    SUBJECT TERMS MRI; white matter hyperintensities; hypobaric exposure; neurological decompression sickness 16. SECURITY CLASSIFICATION OF: 17...normal controls and did not increase with age in pilots, suggesting that hypobaric exposure produces white matter damage different from that occurring in...relapse we observed in 3 NDCS pilots after successful hyperbaric treatment (US Navy Treatment Table 6; 100% fraction of inspired oxygen; 2.8 atm absolute

  1. Netrin-1 overexpression promotes white matter repairing and remodeling after focal cerebral ischemia in mice

    OpenAIRE

    He, Xiaosong; Li, Yaning; Lu, Haiyan; Zhang, Zhijun; Wang, Yongting; Yang, Guo-Yuan

    2013-01-01

    Damage of oligodendrocytes after ischemia has negative impact on white matter integrity and neuronal function. In this work, we explore whether Netrin-1 (NT-1) overexpression facilitates white matter repairing and remodeling. Adult CD-1 mice received stereotactic injection of adeno-associated virus carrying NT-1 gene (AAV-NT-1). One week after gene transfer, mice underwent 60 minutes of middle cerebral artery occlusion. The effect of NT-1 on neural function was evaluated by neurobehavioral te...

  2. Neonatal white matter abnormalities an important predictor of neurocognitive outcome for very preterm children.

    Directory of Open Access Journals (Sweden)

    Lianne J Woodward

    Full Text Available BACKGROUND: Cerebral white matter abnormalities on term MRI are a strong predictor of motor disability in children born very preterm. However, their contribution to cognitive impairment is less certain. OBJECTIVE: Examine relationships between the presence and severity of cerebral white matter abnormalities on neonatal MRI and a range of neurocognitive outcomes assessed at ages 4 and 6 years. DESIGN/METHODS: The study sample consisted of a regionally representative cohort of 104 very preterm (≤32 weeks gestation infants born from 1998-2000 and a comparison group of 107 full-term infants. At term equivalent, all preterm infants underwent a structural MRI scan that was analyzed qualitatively for the presence and severity of cerebral white matter abnormalities, including cysts, signal abnormalities, loss of white matter volume, ventriculomegaly, and corpus callosal thinning/myelination. At corrected ages 4 and 6 years, all children underwent a comprehensive neurodevelopmental assessment that included measures of general intellectual ability, language development, and executive functioning. RESULTS: At 4 and 6 years, very preterm children without cerebral white matter abnormalities showed no apparent neurocognitive impairments relative to their full-term peers on any of the domain specific measures of intelligence, language, and executive functioning. In contrast, children born very preterm with mild and moderate-to-severe white matter abnormalities were characterized by performance impairments across all measures and time points, with more severe cerebral abnormalities being associated with increased risks of cognitive impairment. These associations persisted after adjustment for gender, neonatal medical risk factors, and family social risk. CONCLUSIONS: Findings highlight the importance of cerebral white matter connectivity for later intact cognitive functioning amongst children born very preterm. Preterm born children without cerebral white

  3. Depressive symptoms predict cognitive decline and dementia in older people independently of cerebral white matter changes

    DEFF Research Database (Denmark)

    Verdelho, Ana; Madureira, Sofia; Moleiro, Carla

    2013-01-01

    Depressive symptoms (DS) have been associated with increased risk of cognitive decline. Our aim was to evaluate the longitudinal influence of DS on cognition in independent older people, accounting for the severity of white matter changes (WMC).......Depressive symptoms (DS) have been associated with increased risk of cognitive decline. Our aim was to evaluate the longitudinal influence of DS on cognition in independent older people, accounting for the severity of white matter changes (WMC)....

  4. White matter integrity deficits in prefrontal-amygdala pathways in Williams syndrome.

    Science.gov (United States)

    Avery, Suzanne N; Thornton-Wells, Tricia A; Anderson, Adam W; Blackford, Jennifer Urbano

    2012-01-16

    Williams syndrome is a neurodevelopmental disorder associated with significant non-social fears. Consistent with this elevated non-social fear, individuals with Williams syndrome have an abnormally elevated amygdala response when viewing threatening non-social stimuli. In typically-developing individuals, amygdala activity is inhibited through dense, reciprocal white matter connections with the prefrontal cortex. Neuroimaging studies suggest a functional uncoupling of normal prefrontal-amygdala inhibition in individuals with Williams syndrome, which might underlie both the extreme amygdala activity and non-social fears. This functional uncoupling might be caused by structural deficits in underlying white matter pathways; however, prefrontal-amygdala white matter deficits have yet to be explored in Williams syndrome. We used diffusion tensor imaging to investigate prefrontal-amygdala white matter integrity differences in individuals with Williams syndrome and typically-developing controls with high levels of non-social fear. White matter pathways between the amygdala and several prefrontal regions were isolated using probabilistic tractography. Within each pathway, we tested for between-group differences in three measures of white matter integrity: fractional anisotropy (FA), radial diffusivity (RD), and parallel diffusivity (λ(1)). Individuals with Williams syndrome had lower FA, compared to controls, in several of the prefrontal-amygdala pathways investigated, indicating a reduction in white matter integrity. Lower FA in Williams syndrome was explained by significantly higher RD, with no differences in λ(1), suggestive of lower fiber density or axon myelination in prefrontal-amygdala pathways. These results suggest that deficits in the structural integrity of prefrontal-amygdala white matter pathways might underlie the increased amygdala activity and extreme non-social fears observed in Williams syndrome. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Creatine, Glutamine plus Glutamate, and Macromolecules Are Decreased in the Central White Matter of Premature Neonates around Term.

    Directory of Open Access Journals (Sweden)

    Meriam Koob

    Full Text Available Preterm birth represents a high risk of neurodevelopmental disabilities when associated with white-matter damage. Recent studies have reported cognitive deficits in children born preterm without brain injury on MRI at term-equivalent age. Understanding the microstructural and metabolic underpinnings of these deficits is essential for their early detection. Here, we used diffusion-weighted imaging and single-voxel 1H magnetic resonance spectroscopy (MRS to compare brain maturation at term-equivalent age in premature neonates with no evidence of white matter injury on conventional MRI except diffuse excessive high-signal intensity, and normal term neonates. Thirty-two infants, 16 term neonates (mean post-conceptional age at scan: 39.8±1 weeks and 16 premature neonates (mean gestational age at birth: 29.1±2 weeks, mean post-conceptional age at scan: 39.2±1 weeks were investigated. The MRI/MRS protocol performed at 1.5T involved diffusion-weighted MRI and localized 1H-MRS with the Point RESolved Spectroscopy (PRESS sequence. Preterm neonates showed significantly higher ADC values in the temporal white matter (P<0.05, the occipital white matter (P<0.005 and the thalamus (P<0.05. The proton spectrum of the centrum semiovale was characterized by significantly lower taurine/H2O and macromolecules/H2O ratios (P<0.05 at a TE of 30 ms, and reduced (creatine+phosphocreatine/H2O and (glutamine+glutamate/H2O ratios (P<0.05 at a TE of 135 ms in the preterm neonates than in full-term neonates. Our findings indicate that premature neonates with normal conventional MRI present a delay in brain maturation affecting the white matter and the thalamus. Their brain metabolic profile is characterized by lower levels of creatine, glutamine plus glutamate, and macromolecules in the centrum semiovale, a finding suggesting altered energy metabolism and protein synthesis.

  6. Quantitative ultrasonography of the periventricular white and grey matter of the developing brain.

    Science.gov (United States)

    Mullaart, R A; Thijssen, J M; Rotteveel, J J; Valckx, F M; van Geemen, A J

    1999-05-01

    This study addresses the value of operator-independent computer processing of ultrasonograms of the developing brain. With this aim, routine cranial ultrasonograms obtained from 39 term and preterm infants without clinical or sonographic evidence of brain damage were analyzed by five observers. The procedure, respectively, included: 1. the definition of four regions of interest (ROI), one white matter and one grey matter area on each side of the brain; 2. digitization of the sonogram data within these ROIs; 3. correction for the equipment settings, using data from a tissue-mimicking phantom as a reference; and 4. calculation of four sonogram characteristics (i.e., mean echo level, MEAN, signal-to-noise ratio, SNR, and axial and lateral correlation, CORAX and CORLAT, of the echo level co-occurrence matrix). Significant differences between both sides of the brain or a significant influence of ROI size were not found. The interobserver spread was considerable, but less than the intersubject spread. Two sonogram characteristics seemed strongly correlated in white and grey matter (CORAX and CORLAT) and another only in white matter (SNR with CORAX and CORLAT). MEAN seemed not to be correlated with any other characteristic. Furthermore, it was found that maturation equally decreases white and grey matter MEAN and, thus, hardly affects the ratio between the two. An effect on the other sonogram characteristics was only found in the white matter (i.e., an increase of SNR and a decrease of CORAX and CORLAT). Except for MEAN, the grey matter sonogram characteristics seem hardly affected by maturation. In view of these findings, we conclude that quantitative ultrasonography reveals white and grey matter maturation and, furthermore, provides a conceptional-age-independent reference (MEAN white:grey matter ratio) that might be found to facilitate the detection of pathologic brain alterations.

  7. DCDC2 polymorphism is associated with left temporoparietal gray and white matter structures during development.

    Science.gov (United States)

    Darki, Fahimeh; Peyrard-Janvid, Myriam; Matsson, Hans; Kere, Juha; Klingberg, Torkel

    2014-10-22

    Three genes, DYX1C1, DCDC2, and KIAA0319, have been previously associated with dyslexia, neuronal migration, and ciliary function. Three polymorphisms within these genes, rs3743204 (DYX1C1), rs793842 (DCDC2), and rs6935076 (KIAA0319) have also been linked to normal variability of left temporoparietal white matter volume connecting the middle temporal cortex to the angular and supramarginal gyri. Here, we assessed whether these polymorphisms are also related to the cortical thickness of the associated regions during childhood development using a longitudinal dataset of 76 randomly selected children and young adults who were scanned up to three times each, 2 years apart. rs793842 in DCDC2 was significantly associated with the thickness of left angular and supramarginal gyri as well as the left lateral occipital cortex. The cortex was significantly thicker for T-allele carriers, who also had lower white matter volume and lower reading comprehension scores. There was a negative correlation between white matter volume and cortical thickness, but only white matter volume predicted reading comprehension 2 years after scanning. These results show how normal variability in reading comprehension is related to gene, white matter volume, and cortical thickness in the inferior parietal lobe. Possibly, the variability of gray and white matter structures could both be related to the role of DCDC2 in ciliary function, which affects both neuronal migration and axonal outgrowth. Copyright © 2014 the authors 0270-6474/14/3414455-08$15.00/0.

  8. Effect of antenatal growth and prematurity on brain white matter: diffusion tensor study

    Energy Technology Data Exchange (ETDEWEB)

    Lepomaeki, V. [Turku University Central Hospital, Medical Imaging Centre of Southwest Finland, Turku (Finland); Turku University Central Hospital, Turku PET-Centre, PO Box 52, Turku (Finland); Paavilainen, T.; Komu, M. [Turku University Central Hospital, Medical Imaging Centre of Southwest Finland, Turku (Finland); Matomaeki, J.; Lapinleimu, H.; Liisa Lehtonen, L. [Turku University Central Hospital and University of Turku, Department of Pediatrics, Turku (Finland); Hurme, S. [University of Turku, Department of Biostatistics, Turku (Finland); Haataja, L. [Turku University Central Hospital and University of Turku, Department of Pediatric Neurology, Turku (Finland); Parkkola, R. [Turku University Central Hospital, Medical Imaging Centre of Southwest Finland, Turku (Finland); Turku University Central Hospital, Turku PET-Centre, PO Box 52, Turku (Finland); University of Turku, Department of Diagnostic Radiology, Turku (Finland)

    2012-06-15

    White matter maturation is characterised by increasing fractional anisotropy (FA) and decreasing mean diffusivity (MD). Contradictory results have been published on the effect of premature birth on white matter maturation at term-equivalent age. To assess the association of gestational age and low birth-weight-for-gestational-age (z-score) with white matter maturation. Infants (n = 76, 53 males) born at different gestational ages were imaged at term-equivalent age. Gestational age and birth weight z-score were used as continuous variables and the effect on diffusion parameters was assessed. Brain maturation was studied using regions-of-interest analysis in several white matter areas. Gestational age showed no significant effect on white matter maturation at term-equivalent age. Children with low birth weight z-score had lower FA in the genu and splenium of the corpus callosum (regression, P = 0.012 and P = 0.032; correlation, P = 0.009 and P = 0.006, respectively), and higher MD in the splenium of the corpus callosum (regression, P = 0.002; correlation, P = 0.0004) compared to children whose birth weight was appropriate for gestational age. Children with low birth weight relative to gestational age show delay and/or anomaly in white matter maturation at term-equivalent age. (orig.)

  9. White matter deficits in psychopathic offenders and correlation with factor structure.

    Directory of Open Access Journals (Sweden)

    Sylco S Hoppenbrouwers

    Full Text Available Psychopathic offenders show a persistent pattern of emotional unresponsivity to the often horrendous crimes they perpetrate. Recent studies have related psychopathy to alterations in white matter. Therefore, diffusion tensor imaging followed by tract-based spatial statistics (TBSS analysis in 11 psychopathic offenders matched to 11 healthy controls was completed. Fractional anisotropy was calculated within each voxel and comparisons were made between groups using a permutation test. Any clusters of white matter voxels different between groups were submitted to probabilistic tractography. Significant differences in fractional anisotropy were found between psychopathic offenders and healthy controls in three main white matter clusters. These three clusters represented two major networks: an amygdalo-prefrontal network, and a striato-thalamo-frontal network. The interpersonal/affective component of the PCL-R correlated with white matter deficits in the orbitofrontal cortex and frontal pole whereas the antisocial component correlated with deficits in the striato-thalamo-frontal network. In addition to replicating earlier work concerning disruption of an amygdala-prefrontal network, we show for the first time that white matter integrity in a striato-thalamo-frontal network is disrupted in psychopathic offenders. The novelty of our findings lies in the two dissociable white matter networks that map directly onto the two major factors of psychopathy.

  10. Effect of antenatal growth and prematurity on brain white matter: diffusion tensor study

    International Nuclear Information System (INIS)

    Lepomaeki, V.; Paavilainen, T.; Komu, M.; Matomaeki, J.; Lapinleimu, H.; Liisa Lehtonen, L.; Hurme, S.; Haataja, L.; Parkkola, R.

    2012-01-01

    White matter maturation is characterised by increasing fractional anisotropy (FA) and decreasing mean diffusivity (MD). Contradictory results have been published on the effect of premature birth on white matter maturation at term-equivalent age. To assess the association of gestational age and low birth-weight-for-gestational-age (z-score) with white matter maturation. Infants (n = 76, 53 males) born at different gestational ages were imaged at term-equivalent age. Gestational age and birth weight z-score were used as continuous variables and the effect on diffusion parameters was assessed. Brain maturation was studied using regions-of-interest analysis in several white matter areas. Gestational age showed no significant effect on white matter maturation at term-equivalent age. Children with low birth weight z-score had lower FA in the genu and splenium of the corpus callosum (regression, P = 0.012 and P = 0.032; correlation, P = 0.009 and P = 0.006, respectively), and higher MD in the splenium of the corpus callosum (regression, P = 0.002; correlation, P = 0.0004) compared to children whose birth weight was appropriate for gestational age. Children with low birth weight relative to gestational age show delay and/or anomaly in white matter maturation at term-equivalent age. (orig.)

  11. Fractional anisotropy in white matter tracts of very-low-birth-weight infants

    Energy Technology Data Exchange (ETDEWEB)

    Dudink, Jeroen; Conneman, Nikk; Goudoever, Johannes van; Govaert, Paul [Erasmus MC-Sophia Children' s Hospital, Division of Neonatology, Department of Paediatrics, P.O. Box 2060, Rotterdam (Netherlands); Lequin, Maarten [Erasmus MC-Sophia Children' s Hospital, Division of Paediatrics, Department of Radiology, Rotterdam (Netherlands); Pul, Carola van [Maxima Medical Center, Department of Clinical Physics, Veldhoven (Netherlands); Buijs, Jan [Maxima Medical Center, Division of Neonatology, Department of Paediatrics, Veldhoven (Netherlands)

    2007-12-15

    Advances in neonatal intensive care have not yet reduced the high incidence of neurodevelopmental disability among very-low-birth-weight (VLBW) infants. As neurological deficits are related to white-matter injury, early detection is important. Diffusion tensor imaging (DTI) could be an excellent tool for assessment of white-matter injury. To provide DTI fractional anisotropy (FA) reference values for white-matter tracts of VLBW infants for clinical use. We retrospectively analysed DTI images of 28 VLBW infants (26-32 weeks gestational age) without evidence of white-matter abnormalities on conventional MRI sequences, and normal developmental outcome (assessed at age 1-3 years). For DTI an echoplanar sequence with diffusion gradient (b = 1,000 s/mm{sup 2}) applied in 25 non-collinear directions was used. We measured FA and apparent diffusion coefficient (ADC) of different white-matter tracts in the first 4 days of life. A statistically significant correlation was found between gestational age and FA of the posterior limb of the internal capsule in VLBW infants (r = 0.495, P<0.01). Values of FA and ADC were measured in white-matter tracts of VLBW infants. FA of the pyramidal tracts measured in the first few days after birth is related to gestational age. (orig.)

  12. Reduced thalamic volume in preterm infants is associated with abnormal white matter metabolism independent of injury

    International Nuclear Information System (INIS)

    Wisnowski, Jessica L.; Ceschin, Rafael C.; Choi, So Young; Schmithorst, Vincent J.; Painter, Michael J.; Nelson, Marvin D.; Blueml, Stefan; Panigrahy, Ashok

    2015-01-01

    Altered thalamocortical development is hypothesized to be a key substrate underlying neurodevelopmental disabilities in preterm infants. However, the pathogenesis of this abnormality is not well-understood. We combined magnetic resonance spectroscopy of the parietal white matter and morphometric analyses of the thalamus to investigate the association between white matter metabolism and thalamic volume and tested the hypothesis that thalamic volume would be associated with diminished N-acetyl-aspartate (NAA), a measure of neuronal/axonal maturation, independent of white matter injury. Data from 106 preterm infants (mean gestational age at birth: 31.0 weeks ± 4.3; range 23-36 weeks) who underwent MR examinations under clinical indications were included in this study. Linear regression analyses demonstrated a significant association between parietal white matter NAA concentration and thalamic volume. This effect was above and beyond the effect of white matter injury and age at MRI and remained significant even when preterm infants with punctate white matter lesions (pWMLs) were excluded from the analysis. Furthermore, choline, and among the preterm infants without pWMLs, lactate concentrations were also associated with thalamic volume. Of note, the associations between NAA and choline concentration and thalamic volume remained significant even when the sample was restricted to neonates who were term-equivalent age or older. These observations provide convergent evidence of a neuroimaging phenotype characterized by widespread abnormal thalamocortical development and suggest that the pathogenesis may involve impaired axonal maturation. (orig.)

  13. Fractional anisotropy in white matter tracts of very-low-birth-weight infants

    International Nuclear Information System (INIS)

    Dudink, Jeroen; Conneman, Nikk; Goudoever, Johannes van; Govaert, Paul; Lequin, Maarten; Pul, Carola van; Buijs, Jan

    2007-01-01

    Advances in neonatal intensive care have not yet reduced the high incidence of neurodevelopmental disability among very-low-birth-weight (VLBW) infants. As neurological deficits are related to white-matter injury, early detection is important. Diffusion tensor imaging (DTI) could be an excellent tool for assessment of white-matter injury. To provide DTI fractional anisotropy (FA) reference values for white-matter tracts of VLBW infants for clinical use. We retrospectively analysed DTI images of 28 VLBW infants (26-32 weeks gestational age) without evidence of white-matter abnormalities on conventional MRI sequences, and normal developmental outcome (assessed at age 1-3 years). For DTI an echoplanar sequence with diffusion gradient (b = 1,000 s/mm 2 ) applied in 25 non-collinear directions was used. We measured FA and apparent diffusion coefficient (ADC) of different white-matter tracts in the first 4 days of life. A statistically significant correlation was found between gestational age and FA of the posterior limb of the internal capsule in VLBW infants (r = 0.495, P<0.01). Values of FA and ADC were measured in white-matter tracts of VLBW infants. FA of the pyramidal tracts measured in the first few days after birth is related to gestational age. (orig.)

  14. Reduced thalamic volume in preterm infants is associated with abnormal white matter metabolism independent of injury

    Energy Technology Data Exchange (ETDEWEB)

    Wisnowski, Jessica L. [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); University of Pittsburgh, Department of Pediatric Radiology, Children' s Hospital of Pittsburgh of UPMC, Pittsburgh, PA (United States); University of Southern California, Brain and Creativity Institute, Los Angeles, CA (United States); Ceschin, Rafael C. [University of Pittsburgh, Department of Pediatric Radiology, Children' s Hospital of Pittsburgh of UPMC, Pittsburgh, PA (United States); University of Pittsburgh, Department of Biomedical Informatics, Pittsburgh, PA (United States); Choi, So Young [University of Southern California, Brain and Creativity Institute, Los Angeles, CA (United States); Schmithorst, Vincent J. [University of Pittsburgh, Department of Pediatric Radiology, Children' s Hospital of Pittsburgh of UPMC, Pittsburgh, PA (United States); Painter, Michael J. [University of Pittsburgh, Department of Pediatrics, Division of Neurology, Childrens Hospital of Pittsburgh of UPMC, Pittsburgh, PA (United States); Nelson, Marvin D. [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); Blueml, Stefan [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); Rudi Schulte Research Institute, Santa Barbara, CA (United States); Panigrahy, Ashok [Children' s Hospital Los Angeles, Department of Radiology, Los Angeles, CA (United States); University of Pittsburgh, Department of Pediatric Radiology, Children' s Hospital of Pittsburgh of UPMC, Pittsburgh, PA (United States)

    2015-05-01

    Altered thalamocortical development is hypothesized to be a key substrate underlying neurodevelopmental disabilities in preterm infants. However, the pathogenesis of this abnormality is not well-understood. We combined magnetic resonance spectroscopy of the parietal white matter and morphometric analyses of the thalamus to investigate the association between white matter metabolism and thalamic volume and tested the hypothesis that thalamic volume would be associated with diminished N-acetyl-aspartate (NAA), a measure of neuronal/axonal maturation, independent of white matter injury. Data from 106 preterm infants (mean gestational age at birth: 31.0 weeks ± 4.3; range 23-36 weeks) who underwent MR examinations under clinical indications were included in this study. Linear regression analyses demonstrated a significant association between parietal white matter NAA concentration and thalamic volume. This effect was above and beyond the effect of white matter injury and age at MRI and remained significant even when preterm infants with punctate white matter lesions (pWMLs) were excluded from the analysis. Furthermore, choline, and among the preterm infants without pWMLs, lactate concentrations were also associated with thalamic volume. Of note, the associations between NAA and choline concentration and thalamic volume remained significant even when the sample was restricted to neonates who were term-equivalent age or older. These observations provide convergent evidence of a neuroimaging phenotype characterized by widespread abnormal thalamocortical development and suggest that the pathogenesis may involve impaired axonal maturation. (orig.)

  15. White matter hypoperfusion and damage in dementia: post-mortem assessment.

    Science.gov (United States)

    Love, Seth; Miners, J Scott

    2015-01-01

    Neuroimaging has revealed a range of white matter abnormalities that are common in dementia, some that predict cognitive decline. The abnormalities may result from structural diseases of the cerebral vasculature, such as arteriolosclerosis and amyloid angiopathy, but can also be caused by nonstructural vascular abnormalities (eg, of vascular contractility or permeability), neurovascular instability or extracranial cardiac or vascular disease. Conventional histopathological assessment of the white matter has tended to conflate morphological vascular abnormalities with changes that reflect altered interstitial fluid dynamics or white matter ischemic damage, even though the latter may be of extracranial or nonstructural etiology. However, histopathology is being supplemented by biochemical approaches, including the measurement of proteins involved in the molecular responses to brain ischemia, myelin proteins differentially susceptible to ischemic damage, vessel-associated proteins that allow rapid measurement of microvessel density, markers of blood-brain barrier dysfunction and axonal injury, and mediators of white matter damage. By combining neuroimaging with histopathology and biochemical analysis, we can provide reproducible, quantitative data on the severity of white matter damage, and information on its etiology and pathogenesis. Together these have the potential to inform and improve treatment, particularly in forms of dementia to which white matter hypoperfusion makes a significant contribution. © 2014 International Society of Neuropathology.

  16. Ischemic tolerance in pre-myelinated white matter: the role of astrocyte glycogen in brain pathology.

    Science.gov (United States)

    Fern, Robert

    2015-06-01

    In isolated white matter, ischemic tolerance changes dramatically in the period immediately before the onset of myelination. In the absence of an extrinsic energy source, postnatal day 0 to 2 (P0 to P2) white matter axons are here shown to maintain excitability for over twice as long as axons >P2, a differential that was dependent on glycogen metabolism. Prolonged withdrawal of extrinsic energy supply tended to spare axons in zones around astrocytes, which are shown to be the sole repository for glycogen particles in developing white matter. Analysis of mitochondrial volume fraction revealed that neither axons nor astrocytes had a low metabolic rate in neonatal white matter, while oligodendroglia at older ages had an elevated metabolism. The astrocyte population is established early in neural development, and exhibits reduced cell density as maturation progresses and white matter expands. The findings show that this event establishes the necessary conditions for ischemia sensitivity in white matter and indicates that astrocyte proximity may be significant for the survival of neuronal elements in conditions associated with compromised energy supply.

  17. Sex-related difference in human white matter volumes studied: Inspection of the corpus callosum and other white matter by VBM

    Science.gov (United States)

    Shiino, Akihiko; Chen, Yen-Wei; Tanigaki, Kenji; Yamada, Atsushi; Vigers, Piers; Watanabe, Toshiyuki; Tooyama, Ikuo; Akiguchi, Ichiro

    2017-01-01

    It has been contended that any observed difference of the corpus callosum (CC) size between men and women is not sex-related but brain-size-related. A recent report, however, showed that the midsagittal CC area was significantly larger in women in 37 brain-size-matched pairs of normal young adults. Since this constituted strong evidence of sexual dimorphism and was obtained from publicly available data in OASIS, we examined volume differences within the CC and in other white matter using voxel-based morphometry (VBM). We created a three-dimensional region of interest of the CC and measured its volume. The VBM statistics were analyzed by permutation test and threshold-free cluster enhancement (TFCE) with the significance levels at FWER women in the same 37 brain-size-matched pairs. We found that the CC genu was the subregion showing the most significant sex-related difference. We also found that white matter in the bilateral anterior frontal regions and the left lateral white matter near to Broca’s area were larger in women, whereas there were no significant larger regions in men. Since we used brain-size-matched subjects, our results gave strong volumetric evidence of localized sexual dimorphism of white matter.

  18. Effects of Si on microstructure and phase transformation at elevated temperatures in ferritic white cast irons

    Energy Technology Data Exchange (ETDEWEB)

    Wiengmoon, A., E-mail: ampornw@nu.ac.th [Department of Physics, Faculty of Science, Naresuan University, Phitsanulok 65000 (Thailand); Pearce, J.T.H. [Panyapiwat Institute of Management, Nonthaburi 11120 (Thailand); Nusen, S.; Chairuangsri, T. [Department of Industrial Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2016-10-15

    The effects of Si on microstructure and phase transformation at elevated temperature of ferritic 31wt.%Cr-1.1wt.%C white cast irons with up to 3wt.%Si have been studied. Applications of these irons include parts requiring heat resistance at elevated temperature. The irons were produced by sand casting. The microstructure in as-cast condition and after being subjected to high temperature (700 to 1000 °C) was investigated by light microscopy, X-ray diffraction, and electron microscopy. The results revealed that the as-cast microstructure consisted mainly of primary ferrite dendrites and eutectic (ferrite + M{sub 7}C{sub 3}). Si promotes M{sub 7}C{sub 3}-to-M{sub 23}C{sub 6} transformation in the irons subjected to transformation at elevated temperature, but no sigma phase was found. The extent of M{sub 7}C{sub 3}-to-M{sub 23}C{sub 6} transformation increases proportional to the increasing transformation temperature, holding time and Si content in the irons. For the iron with 1.0wt.%Si content after holding at elevated temperatures, martensite was also found, which could be attributed to carbon accretion effects in eutectic ferrite. Si was incorporated in M{sub 23}C{sub 6} such that M{sub 23}C{sub 6} containing Si can show darker contrast under SEM-BEI as compared to M{sub 7}C{sub 3}; this is the opposite to what has been observed for the cases of typical M{sub 23}C{sub 6} and M{sub 23}C{sub 6} containing Mo or W. The results obtained are important to understand the change in properties of ferritic, high chromium irons containing Si subjected to elevated temperature.

  19. Determinants of cerebral white matter lesions: A longitudinal population based MRI study

    NARCIS (Netherlands)

    H.F. de Leeuw (Frank)

    1999-01-01

    textabstractW hite matter lesions are frequently found on cerebral magnetic resonance imaging scans of elderly non-demented and demented people. l-4 The pathogenesis of white matter lesions is largely unknown. However age and high diastolic and systolic blood pressure levels and indicators of

  20. Effect of early institutionalization and foster care on long-term white matter development: a randomized clinical trial.

    Science.gov (United States)

    Bick, Johanna; Zhu, Tong; Stamoulis, Catherine; Fox, Nathan A; Zeanah, Charles; Nelson, Charles A

    2015-03-01

    Severe neglect in early life is associated with compromises in brain development and associated behavioral functioning. Although early intervention has been shown to support more normative trajectories of brain development, specific improvements in the white matter pathways that underlie emotional and cognitive development are unknown. To examine associations among neglect in early life, early intervention, and the microstructural integrity of white matter pathways in middle childhood. The Bucharest Early Intervention Project is a randomized clinical trial of high-quality foster care as an intervention for institutionally reared children in Bucharest, Romania, from 2000 through the present. During infancy, children were randomly selected to remain in an institution or to be placed in foster care. Those who remained in institutions experienced neglect, including social, emotional, linguistic, and cognitive impoverishment. Developmental trajectories of these children were compared with a group of sociodemographically matched children reared in biological families at baseline and several points throughout development. At approximately 8 years of age, 69 of the original 136 children underwent structural magnetic resonance imaging scans. Four estimates of white matter integrity (fractional anisotropy [FA] and mean [MD], radial [RD], and axial [AD] diffusivity) for 48 white matter tracts throughout the brain were obtained through diffusion tensor imaging. Significant associations emerged between neglect in early life and microstructural integrity of the body of the corpus callosum (FA, β = 0.01 [P = .01]; RD, β = -0.02 [P = .005]; MD, β = -0.01 [P = .02]) and tracts involved in limbic circuitry (fornix crus [AD, β = 0.02 (P = .046)] and cingulum [RD, β = -0.01 (P = .02); MD, β = -0.01 (P = .049)]), frontostriatal circuitry (anterior [AD, β = -0.01 (P = .02)] and superior [AD, β = -0.02 (P = .02); MD, β = -0.01 (P = .03)] corona

  1. Connectivity-enhanced diffusion analysis reveals white matter density disruptions in first episode and chronic schizophrenia

    Directory of Open Access Journals (Sweden)

    Rachael G. Grazioplene

    microstructural group differences. These results underline the need to move beyond tensor-based models in favor of acquisition and analysis techniques that can help disambiguate different sources of white matter disruptions associated with schizophrenia. Keywords: Schizophrenia, Diffusion imaging, DWI, DTI, First episode, Chronic, White matter, Fiber density, Fiber organization

  2. White matter pathology in ALS and lower motor neuron ALS variants: a diffusion tensor imaging study using tract-based spatial statistics.

    Science.gov (United States)

    Prudlo, Johannes; Bißbort, Charlotte; Glass, Aenne; Grossmann, Annette; Hauenstein, Karlheinz; Benecke, Reiner; Teipel, Stefan J

    2012-09-01

    The aim of this work was to investigate white-matter microstructural changes within and outside the corticospinal tract in classical amyotrophic lateral sclerosis (ALS) and in lower motor neuron (LMN) ALS variants by means of diffusion tensor imaging (DTI). We investigated 22 ALS patients and 21 age-matched controls utilizing a whole-brain approach with a 1.5-T scanner for DTI. The patient group was comprised of 15 classical ALS- and seven LMN ALS-variant patients (progressive muscular atrophy, flail arm and flail leg syndrome). Disease severity was measured by the revised version of the functional rating scale. White matter fractional anisotropy (FA) was assessed using tract-based spatial statistics (TBSS) and a region of interest (ROI) approach. We found significant FA reductions in motor and extra-motor cerebral fiber tracts in classical ALS and in the LMN ALS-variant patients compared to controls. The voxel-based TBSS results were confirmed by the ROI findings. The white matter damage correlated with the disease severity in the patient group and was found in a similar distribution, but to a lesser extent, among the LMN ALS-variant subgroup. ALS and LMN ALS variants are multisystem degenerations. DTI shows the potential to determine an earlier diagnosis, particularly in LMN ALS variants. The statistically identical findings of white matter lesions in classical ALS and LMN variants as ascertained by DTI further underline that these variants should be regarded as part of the ALS spectrum.

  3. Information processing speed mediates the relationship between white matter and general intelligence in schizophrenia.

    Science.gov (United States)

    Alloza, Clara; Cox, Simon R; Duff, Barbara; Semple, Scott I; Bastin, Mark E; Whalley, Heather C; Lawrie, Stephen M

    2016-08-30

    Several authors have proposed that schizophrenia is the result of impaired connectivity between specific brain regions rather than differences in local brain activity. White matter abnormalities have been suggested as the anatomical substrate for this dysconnectivity hypothesis. Information processing speed may act as a key cognitive resource facilitating higher order cognition by allowing multiple cognitive processes to be simultaneously available. However, there is a lack of established associations between these variables in schizophrenia. We hypothesised that the relationship between white matter and general intelligence would be mediated by processing speed. White matter water diffusion parameters were studied using Tract-based Spatial Statistics and computed within 46 regions-of-interest (ROI). Principal component analysis was conducted on these white matter ROI for fractional anisotropy (FA) and mean diffusivity, and on neurocognitive subtests to extract general factors of white mater structure (gFA, gMD), general intelligence (g) and processing speed (gspeed). There was a positive correlation between g and gFA (r= 0.67, p =0.001) that was partially and significantly mediated by gspeed (56.22% CI: 0.10-0.62). These findings suggest a plausible model of structure-function relations in schizophrenia, whereby white matter structure may provide a neuroanatomical substrate for general intelligence, which is partly supported by speed of information processing. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  4. The effects of the serotonin transporter polymorphism and age on frontal white matter integrity in healthy adult women.

    Directory of Open Access Journals (Sweden)

    Rune eJonassen

    2012-02-01

    Full Text Available Studies of populations at genetic risk have the potential to explore the underlying structural and functional mechanisms in the development of psychological disorders. The polymorphic region (5-HTTLPR in the serotonin transporter gene (SLC6A4 has been associated with major depression (Caspi et al., 2003. In healthy women, variation in the human brain white matter microstructure integrity in the uncinate fascicule (UF has been suggested as an endophenotypes in the development of major depression (MDD. Pacheco et al. (2009 found a unique effect of age and 5-HTTLPR within the left frontal UF. The present study examined whether these associations persist along the adult life span. Thirty-seven right-handed healthy women between 21 and 61 years of age were invited for a diffusion MRI study. The functional polymorphism 5-HTTLPR located in the promoter region of the SLC6A4 gene was genotyped using polymerase chain reaction (PCR. Fractional anisotropy (FA was generated for the UF based on Tract-Based Spatial Statistics (TBSS. Models of emotion regulation circuitry suggest that working memory is important in conscious emotion regulation (Price and Drevets, 2010. To explore if 5-HTTLPR is related to this aspects of emotion processing, a working memory pathway, the superior longitudinal fascicule (SLF was included. The results demonstrate that age may explain the hypothesized association between 5-HTTLPR and frontal uncinate fascicule white matter integrity in healthy adult women. Both white matter changes associated with the aging process and those associated with growth and development may explain why the earlier reported unique effects of genotype in frontal UF FA do not persist into adulthood.

  5. Development of the Cell Population in the Brain White Matter of Young Children

    DEFF Research Database (Denmark)

    Sigaard, Rasmus Krarup; Kjær, Majken; Pakkenberg, Bente

    2014-01-01

    While brain gray matter is primarily associated with sensorimotor processing and cognition, white matter modulates the distribution of action potentials, coordinates communication between different brain regions, and acts as a relay for input/output signals. Previous studies have described......, and microglia) in the cerebral white matter of 9 infants aged 0-33 months, using design-based stereological methods to obtain quantitative data about brain development. There were linear increases with age in the numbers of oligodendrocytes (7-28 billion) and astrocytes (1.5-6.7 billion) during the first 3...

  6. MRI markers for mild cognitive impairment: comparisons between white matter integrity and gray matter volume measurements.

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    Full Text Available The aim of the study was to evaluate the value of assessing white matter integrity using diffusion tensor imaging (DTI for classification of mild cognitive impairment (MCI and prediction of cognitive impairments in comparison to brain atrophy measurements using structural MRI. Fifty-one patients with MCI and 66 cognitive normal controls (CN underwent DTI and T1-weighted structural MRI. DTI measures included fractional anisotropy (FA and radial diffusivity (DR from 20 predetermined regions-of-interest (ROIs in the commissural, limbic and association tracts, which are thought to be involved in Alzheimer's disease; measures of regional gray matter (GM volume included 21 ROIs in medial temporal lobe, parietal cortex, and subcortical regions. Significant group differences between MCI and CN were detected by each MRI modality: In particular, reduced FA was found in splenium, left isthmus cingulum and fornix; increased DR was found in splenium, left isthmus cingulum and bilateral uncinate fasciculi; reduced GM volume was found in bilateral hippocampi, left entorhinal cortex, right amygdala and bilateral thalamus; and thinner cortex was found in the left entorhinal cortex. Group classifications based on FA or DR was significant and better than classifications based on GM volume. Using either DR or FA together with GM volume improved classification accuracy. Furthermore, all three measures, FA, DR and GM volume were similarly accurate in predicting cognitive performance in MCI patients. Taken together, the results imply that DTI measures are as accurate as measures of GM volume in detecting brain alterations that are associated with cognitive impairment. Furthermore, a combination of DTI and structural MRI measurements improves classification accuracy.

  7. Regional White Matter Decreases in Alzheimer's Disease Using Optimized Voxel-Based Morphometry

    International Nuclear Information System (INIS)

    Shuyu Li; Fang Pu; Feng Shi; Sheng Xie; Yinhua Wang; Tianzi Jiang

    2008-01-01

    Background: Most studies that attempt to clarify structural abnormalities related to functional disconnection in patients with Alzheimer's disease (AD) have focused on exploring pathological changes in cortical gray matter. However, white matter fibers connecting these cerebral areas may also be abnormal. Purpose: To investigate the regional changes of white matter volume in patients with AD compared to healthy subjects. Material and Methods: White matter volume changes in whole-brain magnetic resonance images acquired from 19 patients with AD and 20 healthy subjects (control group) were observed using the optimized voxel-based morphometry (VBM) method. In addition, the corpus callosum (CC) of AD patients and the control group was investigated further by outlining manually the boundary of the CC on a midsagittal slice. Each area of the CC was then corrected by dividing each subject's intracranial area in the midsagittal plane. Results: Compared with the control group, AD patients showed significantly reduced white matter volumes in the posterior part of the CC and the temporal lobe in the left and right hemispheres. Moreover, the voxel showing peak statistical difference in the posterior of the CC was left sided. The five subdivisions of the CC were also significantly smaller among the AD patients relative to the control group. Conclusion: Our findings suggest that these abnormalities in white matter regions may contribute to the functional disconnections in AD

  8. Regional White Matter Decreases in Alzheimer's Disease Using Optimized Voxel-Based Morphometry

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    Shuyu Li; Fang Pu; Feng Shi; Sheng Xie; Yinhua Wang; Tianzi Jiang [Dept. of Bioengineering, Beijing Univ. of Aeronautics and Astronautics, Beijing (China)

    2008-02-15

    Background: Most studies that attempt to clarify structural abnormalities related to functional disconnection in patients with Alzheimer's disease (AD) have focused on exploring pathological changes in cortical gray matter. However, white matter fibers connecting these cerebral areas may also be abnormal. Purpose: To investigate the regional changes of white matter volume in patients with AD compared to healthy subjects. Material and Methods: White matter volume changes in whole-brain magnetic resonance images acquired from 19 patients with AD and 20 healthy subjects (control group) were observed using the optimized voxel-based morphometry (VBM) method. In addition, the corpus callosum (CC) of AD patients and the control group was investigated further by outlining manually the boundary of the CC on a midsagittal slice. Each area of the CC was then corrected by dividing each subject's intracranial area in the midsagittal plane. Results: Compared with the control group, AD patients showed significantly reduced white matter volumes in the posterior part of the CC and the temporal lobe in the left and right hemispheres. Moreover, the voxel showing peak statistical difference in the posterior of the CC was left sided. The five subdivisions of the CC were also significantly smaller among the AD patients relative to the control group. Conclusion: Our findings suggest that these abnormalities in white matter regions may contribute to the functional disconnections in AD.

  9. Regional White Matter Decreases in Alzheimer's Disease Using Optimized Voxel-Based Morphometry

    Energy Technology Data Exchange (ETDEWEB)

    Shuyu Li; Fang Pu; Feng Shi; Sheng Xie; Yinhua Wang; Tianzi Jiang (Dept. of Bioengineering, Beijing Univ. of Aeronautics and Astronautics, Beijing (China))

    2008-02-15

    Background: Most studies that attempt to clarify structural abnormalities related to functional disconnection in patients with Alzheimer's disease (AD) have focused on exploring pathological changes in cortical gray matter. However, white matter fibers connecting these cerebral areas may also be abnormal. Purpose: To investigate the regional changes of white matter volume in patients with AD compared to healthy subjects. Material and Methods: White matter volume changes in whole-brain magnetic resonance images acquired from 19 patients with AD and 20 healthy subjects (control group) were observed using the optimized voxel-based morphometry (VBM) method. In addition, the corpus callosum (CC) of AD patients and the control group was investigated further by outlining manually the boundary of the CC on a midsagittal slice. Each area of the CC was then corrected by dividing each subject's intracranial area in the midsagittal plane. Results: Compared with the control group, AD patients showed significantly reduced white matter volumes in the posterior part of the CC and the temporal lobe in the left and right hemispheres. Moreover, the voxel showing peak statistical difference in the posterior of the CC was left sided. The five subdivisions of the CC were also significantly smaller among the AD patients relative to the control group. Conclusion: Our findings suggest that these abnormalities in white matter regions may contribute to the functional disconnections in AD

  10. Voxel-based MRI intensitometry reveals extent of cerebral white matter pathology in amyotrophic lateral sclerosis.

    Directory of Open Access Journals (Sweden)

    Viktor Hartung

    Full Text Available Amyotrophic lateral sclerosis (ALS is characterized by progressive loss of upper and lower motor neurons. Advanced MRI techniques such as diffusion tensor imaging have shown great potential in capturing a common white matter pathology. However the sensitivity is variable and diffusion tensor imaging is not yet applicable to the routine clinical environment. Voxel-based morphometry (VBM has revealed grey matter changes in ALS, but the bias-reducing algorithms inherent to traditional VBM are not optimized for the assessment of the white matter changes. We have developed a novel approach to white matter analysis, namely voxel-based intensitometry (VBI. High resolution T1-weighted MRI was acquired at 1.5 Tesla in 30 ALS patients and 37 age-matched healthy controls. VBI analysis at the group level revealed widespread white matter intensity increases in the corticospinal tracts, corpus callosum, sub-central, frontal and occipital white matter tracts and cerebellum. VBI results correlated with disease severity (ALSFRS-R and patterns of cerebral involvement differed between bulbar- and limb-onset. VBI would be easily translatable to the routine clinical environment, and once optimized for individual analysis offers significant biomarker potential in ALS.

  11. White matter alterations in neurodegenerative and vascular dementia; Marklagerveraenderungen bei neurodegenerativen und vaskulaeren Demenzerkrankungen

    Energy Technology Data Exchange (ETDEWEB)

    Supprian, T. [Arbeitsgruppe Gerontopsychiatrie, Universitaets-Nervenklinik Homburg (Germany); Arbeitsgruppe Gerontopsychiatrie, Universitaets-Nervenklinik, Psychiatrie und Psychotherapie, 66421, Homburg (Germany); Kessler, H.; Falkai, P. [Arbeitsgruppe Gerontopsychiatrie, Universitaets-Nervenklinik Homburg (Germany); Retz, W.; Roesler, M. [Arbeitsgruppe Gerontopsychiatrie, Universitaets-Nervenklinik Homburg (Germany); Institut fuer gerichtliche Psychologie und Psychiatrie, Universitaet des Saarlandes, Homburg (Germany); Grunwald, I.; Reith, W. [Abteilung fuer Neuroradiologie, Universitaetskliniken des Saarlandes, Homburg (Germany)

    2003-07-01

    Due to a significant overlap of the two syndromes, differentiation of degenerative dementia of the Alzheimer-type from vascular dementia may be difficult even when imaging studies are available. White matter changes occur in many patients suffering from Alzheimer's disease. Little is known about the impact of white matter changes on the course and clinical presentation of Alzheimer's disease. High sensitivity of MRI in the detection of white matter alterations may account for over-diagnosing vascular dementia. The clinical significance of white matter alterations in dementia is still a matter of debate. The article reviews current concepts about the role of white matter alterations in dementia. (orig.) [German] Die Zuordnung einer Demenzerkrankung zu einem neurodegenerativen Pathomechanismus, wie der Demenz vom Alzheimer-Typ (DAT) oder einem vaskulaeren Pathomechanismus, kann trotz der Verfuegbarkeit bildgebender Verfahren Probleme bereiten. Ueberlappungen neurodegenerativer und vaskulaerer Mechanismen sind haeufig. Mikroangiopathische Veraenderungen des Marklagers finden sich bei einem hohen Anteil von Patienten mit der klinischen Verlaufsform einer Demenz vom Alzheimer-Typ. Es ist unklar, ob es sich um eine Koinzidenz zweier Pathomechanismen handelt oder ob eine wechselseitige Beeinflussung stattfindet. Die hohe Sensitivitaet der Magnetresonanztomographie bei der Erfassung mikroangiopathischer Veraenderungen des Marklagers koennte dazu fuehren, dass zu vaskulaere Demenzerkrankungen haeufig diagnostiziert werden. Der Einfluss mikroangiopathischer Veraenderungen des Marklagers auf den Demenzverlauf wird kontrovers diskutiert. Die vorgelegte Arbeit gibt eine Uebersicht ueber die aktuellen Konzepte zum Stellenwert von Marklagerveraenderungen bei Demenzerkrankungen. (orig.)

  12. White matter integrity as a predictor of response to treatment in first episode psychosis.

    Science.gov (United States)

    Reis Marques, Tiago; Taylor, Heather; Chaddock, Chris; Dell'acqua, Flavio; Handley, Rowena; Reinders, A A T Simone; Mondelli, Valeria; Bonaccorso, Stefania; Diforti, Marta; Simmons, Andrew; David, Anthony S; Murray, Robin M; Pariante, Carmine M; Kapur, Shitij; Dazzan, Paola

    2014-01-01

    The integrity of brain white matter connections is central to a patient's ability to respond to pharmacological interventions. This study tested this hypothesis using a specific measure of white matter integrity, and examining its relationship to treatment response using a prospective design in patients within their first episode of psychosis. Diffusion tensor imaging data were acquired in 63 patients with first episode psychosis and 52 healthy control subjects (baseline). Response was assessed after 12 weeks and patients were classified as responders or non-responders according to treatment outcome. At this second time-point, they also underwent a second diffusion tensor imaging scan. Tract-based spatial statistics were used to assess fractional anisotropy as a marker of white matter integrity. At baseline, non-responders showed lower fractional anisotropy than both responders and healthy control subjects (P psychosis. These data, together with earlier findings on cortical grey matter, suggest that grey and white matter integrity at the start of treatment is an important moderator of response to antipsychotics. These findings can inform patient stratification to anticipate care needs, and raise the possibility that antipsychotics may restore white matter integrity as part of the therapeutic response.

  13. Blood Pressure Control in Aging Predicts Cerebral Atrophy Related to Small-Vessel White Matter Lesions

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    Kyle C. Kern

    2017-05-01

    Full Text Available Cerebral small-vessel damage manifests as white matter hyperintensities and cerebral atrophy on brain MRI and is associated with aging, cognitive decline and dementia. We sought to examine the interrelationship of these imaging biomarkers and the influence of hypertension in older individuals. We used a multivariate spatial covariance neuroimaging technique to localize the effects of white matter lesion load on regional gray matter volume and assessed the role of blood pressure control, age and education on this relationship. Using a case-control design matching for age, gender, and educational attainment we selected 64 participants with normal blood pressure, controlled hypertension or uncontrolled hypertension from the Northern Manhattan Study cohort. We applied gray matter voxel-based morphometry with the scaled subprofile model to (1 identify regional covariance patterns of gray matter volume differences associated with white matter lesion load, (2 compare this relationship across blood pressure groups, and (3 relate it to cognitive performance. In this group of participants aged 60–86 years, we identified a pattern of reduced gray matter volume associated with white matter lesion load in bilateral temporal-parietal regions with relative preservation of volume in the basal forebrain, thalami and cingulate cortex. This pattern was expressed most in the uncontrolled hypertension group and least in the normotensives, but was also more evident in older and more educated individuals. Expression of this pattern was associated with worse performance in executive function and memory. In summary, white matter lesions from small-vessel disease are associated with a regional pattern of gray matter atrophy that is mitigated by blood pressure control, exacerbated by aging, and associated with cognitive performance.

  14. The impact of fibre orientation on T1-relaxation and apparent tissue water content in white matter.

    Science.gov (United States)

    Schyboll, Felix; Jaekel, Uwe; Weber, Bernd; Neeb, Heiko

    2018-02-20

    Recent MRI studies have shown that the orientation of nerve fibres relative to the main magnetic field affects the R 2 *(= 1/T 2 *) relaxation rate in white matter (WM) structures. The underlying physical causes have been discussed in several studies but are still not completely understood. However, understanding these effects in detail is of great importance since this might serve as a basis for the development of new diagnostic tools and/or improve quantitative susceptibility mapping techniques. Therefore, in addition to the known angular dependence of R 2 *, the current study investigates the relationship between fibre orientation and the longitudinal relaxation rate, R 1 (= 1/T 1 ), as well as the apparent water content. For a group of 16 healthy subjects, a series of gradient echo, echo-planar and diffusion weighted images were acquired at 3T from which the decay rates, the apparent water content and the diffusion direction were reconstructed. The diffusion weighted data were used to determine the angle between the principle fibre direction and the main magnetic field to examine the angular dependence of R 1 and apparent water content. The obtained results demonstrate that both parameters depend on the fibre orientation and exhibit a positive correlation with the angle between fibre direction and main magnetic field. These observations could be helpful to improve and/or constrain existing biophysical models of brain microstructure by imposing additional constraints resulting from the observed angular dependence R 1 and apparent water content in white matter.

  15. Financial literacy is associated with white matter integrity in old age.

    Science.gov (United States)

    Han, S Duke; Boyle, Patricia A; Arfanakis, Konstantinos; Fleischman, Debra; Yu, Lei; James, Bryan D; Bennett, David A

    2016-04-15

    Financial literacy, the ability to understand, access, and utilize information in ways that contribute to optimal financial outcomes, is important for independence and wellbeing in old age. We previously reported that financial literacy is associated with greater functional connectivity between brain regions in old age. Here, we tested the hypothesis that higher financial literacy would be associated with greater white matter integrity in old age. Participants included 346 persons without dementia (mean age=81.36, mean education=15.39, male/female=79/267, mean MMSE=28.52) from the Rush Memory and Aging Project. Financial literacy was assessed using a series of questions imbedded as part of an ongoing decision making study. White matter integrity was assessed with diffusion anisotropy measured with diffusion tensor magnetic resonance imaging (DTI). We tested the hypothesis that higher financial literacy is associated with higher diffusion anisotropy in white matter, adjusting for the effects of age, education, sex, and white matter hyperintense lesions. We then repeated the analysis also adjusting for cognitive function. Analyses revealed regions with significant positive associations between financial literacy and diffusion anisotropy, and many remained significant after accounting for cognitive function. White matter tracts connecting right hemisphere temporal-parietal brain regions were particularly implicated. Greater financial literacy is associated with higher diffusion anisotropy in white matter of nondemented older adults after adjusting for important covariates. These results suggest that financial literacy is positively associated with white matter integrity in old age. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  16. Increased White Matter Inflammation in Aging- and Alzheimer’s Disease Brain

    Directory of Open Access Journals (Sweden)

    Divya Raj

    2017-06-01

    Full Text Available Chronic neuroinflammation, which is primarily mediated by microglia, plays an essential role in aging and neurodegeneration. It is still unclear whether this microglia-induced neuroinflammation occurs globally or is confined to distinct brain regions. In this study, we investigated microglia activity in various brain regions upon healthy aging and Alzheimer’s disease (AD-related pathology in both human and mouse samples. In purified microglia isolated from aging mouse brains, we found a profound gene expression pattern related to pro-inflammatory processes, phagocytosis, and lipid homeostasis. Particularly in white matter microglia of 24-month-old mice, abundant expression of phagocytic markers including Mac-2, Axl, CD16/32, Dectin1, CD11c, and CD36 was detected. Interestingly, in white matter of human brain tissue the first signs of inflammatory activity were already detected during middle age. Thus quantification of microglial proteins, such as CD68 (commonly associated with phagocytosis and HLA-DR (associated with antigen presentation, in postmortem human white matter brain tissue showed an age-dependent increase in immunoreactivity already in middle-aged people (53.2 ± 2.0 years. This early inflammation was also detectable by non-invasive positron emission tomography imaging using [11C]-(R-PK11195, a ligand that binds to activated microglia. Increased microglia activity was also prominently present in the white matter of human postmortem early-onset AD (EOAD brain tissue. Interestingly, microglia activity in the white matter of late-onset AD (LOAD CNS was similar to that of the aged clinically silent AD cases. These data indicate that microglia-induced neuroinflammation is predominant in the white matter of aging mice and humans as well as in EOAD brains. This white matter inflammation may contribute to the progression of neurodegeneration, and have prognostic value for detecting the onset and progression of aging and neurodegeneration.

  17. Cortisol Reactivity to Stress and Its Association With White Matter Integrity in Adults With Schizophrenia.

    Science.gov (United States)

    Nugent, Katie L; Chiappelli, Joshua; Sampath, Hemalatha; Rowland, Laura M; Thangavelu, Kavita; Davis, Beshaun; Du, Xiaoming; Muellerklein, Florian; Daughters, Stacey; Kochunov, Peter; Hong, L Elliot

    2015-09-01

    Although acute hypothalamic-pituitary-adrenal axis response to stress is often adaptive, prolonged responses may have detrimental effects. Many components of white matter structures are sensitive to prolonged cortisol exposure. We aimed to identify a behavioral laboratory assay for cortisol response related to brain pathophysiology in schizophrenia. We hypothesized that an abnormally prolonged cortisol response to stress may be linked to abnormal white matter integrity in patients with schizophrenia. Acute and prolonged salivary cortisol response was measured outside the scanner at pretest and then at 0, 20, and 40 minutes after a psychological stress task in patients with schizophrenia (n = 45) and controls (n = 53). Tract-averaged white matter was measured by 64-direction diffusion tensor imaging in a subset of patients (n = 30) and controls (n = 33). Patients who did not tolerate the psychological stress task and quit had greater acute (t = 2.52 [p = .016] and t = 3.51 [p = .001] at 0 and 20 minutes) and prolonged (t = 3.62 [p = .001] at 40 minutes) cortisol reactivity compared with patients who finished the task. Abnormally prolonged cortisol reactivity in patients was significantly associated with reduced white matter integrity (r = -0.468, p = .009). Regardless of task completion status, acute cortisol response was not related to the white matter measures in patients or controls. This paradigm was successful at identifying a subset of patients whose cortisol response was associated with brain pathophysiology. Abnormal cortisol response may adversely affect white matter integrity, partly explaining this pathology observed in schizophrenia. Prolonged stress responses may be targeted for intervention to test for protective effects against white matter damages.

  18. Grey and white matter changes across the amyotrophic lateral sclerosis-frontotemporal dementia continuum.

    Directory of Open Access Journals (Sweden)

    Patricia Lillo

    Full Text Available There is increasing evidence that amyotrophic lateral sclerosis (ALS and frontotemporal dementia (FTD lie on a clinical, pathological and genetic continuum with patients of one disease exhibiting features of the other. Nevertheless, to date, the underlying grey matter and white matter changes across the ALS-FTD disease continuum have not been explored. In this study fifty-three participants with ALS (n = 10, ALS-FTD (n = 10 and behavioural variant FTD (bvFTD; n = 15 as well as controls (n = 18, underwent detailed clinical assessment plus structural imaging using voxel-based morphometry (VBM and diffusion tensor imaging (DTI analysis of magnetic resonance brain imaging to examine grey and white matter differences and commonalities across the continuum. Importantly, patient groups were matched for age, education, gender and disease duration. VBM and DTI results showed that changes in the ALS group were confined mainly to the motor cortex and anterior cingulate as well as their underlying white matter tracts. ALS-FTD and bvFTD showed widespread grey matter and white matter changes involving frontal and temporal lobes. Extensive prefrontal cortex changes emerged as a marker for bvFTD compared to other subtypes, while ALS-FTD could be distinguished from ALS by additional temporal lobe grey and white matter changes. Finally, ALS could be mainly distinguished from the other two groups by corticospinal tract degeneration. The present study shows for the first time that FTD and ALS overlap in anterior cingulate, motor cortex and related white matter tract changes across the whole continuum. Nevertheless, frontal and temporal atrophy as well as corticospinal tract degeneration emerged as marker for subtype classification, which will inform future diagnosis and target disease management across the continuum.

  19. Gray, White Matter Concentration Changes and Their Correlation with Heterotopic Neurons in Temporal Lobe Epilepsy

    Energy Technology Data Exchange (ETDEWEB)

    Tae, Woo Suk; Joo, Eun Yun; Kim, Sung Tae; Hong, Seung Bong [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2010-02-15

    To identify changes in gray and white matter concentrations (GMC, WMC), and their relation to heterotopic neuron numbers in mesial temporal lobe epilepsy (mTLE). The gray matter or white matter concentrations of 16 left and 15 right mTLE patients who achieved an excellent surgical outcome were compared with those of 24 healthy volunteers for the left group and with 23 healthy volunteers for the right group, by optimized voxel-based morphometry using unmodulated and modulated images. A histologic count of heterotopic neurons was obtained in the white matter of the anterior temporal lobe originating from the patients' surgical specimens. In addition, the number of heterotopic neurons were tested to determine if there was a correlation with the GMC or WMC. The GMCs of the left and right mTLE groups were reduced in the ipsilateral hippocampi, bilateral thalami, precentral gyri, and in the cerebellum. The WMCs were reduced in the ipsilateral white matter of the anterior temporal lobe, bilateral parahippocampal gyri, and internal capsules, but increased in the pons and bilateral precentral gyri. The heterotopic neuron counts in the left mTLE group showed a positive correlation (r = 0.819, p < 0.0001) with GMCs and a negative correlation (r = - 0.839, p < 0.0001) with WMCs in the white matter of the anterior temporal lobe. The present study shows the abnormalities of the cortico-thalamo- hippocampal network including a gray matter volume reduction in the anterior frontal lobes and an abnormality of brain tissue concentration in the pontine area. Furthermore, heterotopic neuron numbers were significantly correlated with GMC or WMC in the left white matter of anterior temporal lobe.

  20. Comparison of grey matter volume and thickness for analysing cortical changes in chronic schizophrenia: a matter of surface area, grey/white matter intensity contrast, and curvature.

    Science.gov (United States)

    Kong, Li; Herold, Christina J; Zöllner, Frank; Salat, David H; Lässer, Marc M; Schmid, Lena A; Fellhauer, Iven; Thomann, Philipp A; Essig, Marco; Schad, Lothar R; Erickson, Kirk I; Schröder, Johannes

    2015-02-28

    Grey matter volume and cortical thickness are the two most widely used measures for detecting grey matter morphometric changes in various diseases such as schizophrenia. However, these two measures only share partial overlapping regions in identifying morphometric changes. Few studies have investigated the contributions of the potential factors to the differences of grey matter volume and cortical thickness. To investigate this question, 3T magnetic resonance images from 22 patients with schizophrenia and 20 well-matched healthy controls were chosen for analyses. Grey matter volume and cortical thickness were measured by VBM and Freesurfer. Grey matter volume results were then rendered onto the surface template of Freesurfer to compare the differences from cortical thickness in anatomical locations. Discrepancy regions of the grey matter volume and thickness where grey matter volume significantly decreased but without corresponding evidence of cortical thinning involved the rostral middle frontal, precentral, lateral occipital and superior frontal gyri. Subsequent region-of-interest analysis demonstrated that changes in surface area, grey/white matter intensity contrast and curvature accounted for the discrepancies. Our results suggest that the differences between grey matter volume and thickness could be jointly driven by surface area, grey/white matter intensity contrast and curvature. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  1. Running exercise protects the capillaries in white matter in a rat model of depression.

    Science.gov (United States)

    Chen, Lin-Mu; Zhang, Ai-Pin; Wang, Fei-Fei; Tan, Chuan-Xue; Gao, Yuan; Huang, Chun-Xia; Zhang, Yi; Jiang, Lin; Zhou, Chun-Ni; Chao, Feng-Lei; Zhang, Lei; Tang, Yong

    2016-12-01

    Running has been shown to improve depressive symptoms when used as an adjunct to medication. However, the mechanisms underlying the antidepressant effects of running are not fully understood. Changes of capillaries in white matter have been discovered in clinical patients and depression model rats. Considering the important part of white matter in depression, running may cause capillary structural changes in white matter. Chronic unpredictable stress (CUS) rats were provided with a 4-week running exercise (from the fifth week to the eighth week) for 20 minutes each day for 5 consecutive days each week. Anhedonia was measured by a behavior test. Furthermore, capillary changes were investigated in the control group, the CUS/Standard group, and the CUS/Running group using stereological methods. The 4-week running increased sucrose consumption significantly in the CUS/Running group and had significant effects on the total volume, total length, and total surface area of the capillaries in the white matter of depression rats. These results demonstrated that exercise-induced protection of the capillaries in white matter might be one of the structural bases for the exercise-induced treatment of depression. It might provide important parameters for further study of the vascular mechanisms of depression and a new research direction for the development of clinical antidepressant means. J. Comp. Neurol. 524:3577-3586, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  2. Oxidative Glial Cell Damage Associated with White Matter Lesions in the Aging Human Brain.

    Science.gov (United States)

    Al-Mashhadi, Sufana; Simpson, Julie E; Heath, Paul R; Dickman, Mark; Forster, Gillian; Matthews, Fiona E; Brayne, Carol; Ince, Paul G; Wharton, Stephen B

    2015-09-01

    White matter lesions (WML) are common in brain aging and are associated with dementia. We aimed to investigate whether oxidative DNA damage and occur in WML and in apparently normal white matter in cases with lesions. Tissue from WML and control white matter from brains with lesions (controls lesional) and without lesions (controls non-lesional) were obtained, using post-mortem magnetic resonance imaging-guided sampling, from the Medical Research Council Cognitive Function and Ageing Study. Oxidative damage was assessed by immunohistochemistry to 8-hydroxy-2'-deoxoguanosine (8-OHdG) and Western blotting for malondialdehyde. DNA response was assessed by phosphorylated histone H2AX (γH2AX), p53, senescence markers and by quantitative Reverse transcription polymerase chain reaction (RT-PCR) panel for candidate DNA damage-associated genes. 8-OHdG was expressed in glia and endothelium, with increased expression in both WML and controls lesional compared with controls non-lesional (P glial dysfunction. Their expression in apparently normal white matter in cases with WML suggests that white matter dysfunction is not restricted to lesions. The role of this field-effect lesion pathogenesis and cognitive impairment are areas to be defined. © 2014 The Authors. Brain Pathology published by John Wiley & Sons Ltd on behalf of International Society of Neuropathology.

  3. Diffusion-Weighted MR Imaging of Unusual White Matter Lesion in a Patient with Menkes Disease

    International Nuclear Information System (INIS)

    Lee, Eun Shin; Ryoo, Jae Wook; Choi, Dae Seob; Cho, Jae Min; Kwon, Soo Hyun; Shin, Hee Suk

    2007-01-01

    We report here on the diffusion-weighted imaging of unusual white matter lesions in a case of Menkes disease. On the initial MR imaging, the white matter lesions were localized in the deep periventricular white matter in the absence of diffuse cortical atrophy. The lesion showed diffuse high signal on the diffusion weighted images and diffuse progression and persistent hyperintensity on the follow up imaging. Our case suggests that the white matter lesion may precede diffuse cortical atrophy in a patient with Menkes disease. Menkes disease is an X-linked disorder that's caused by impaired intracellular transport of copper. We describe here the DWI findings of unusual and progressive white matter lesions in a case of Menkes disease. Menkes disease is an X-linked recessive disorder, and it is due to an inborn error of copper metabolism. The cause of Menkes disease has been isolated to a genetic defect in copper-transporting adenosine triphosphatase, and this results in low levels of intracellular copper. It is characterized clinically by failure to thrive, retarded mental and motor development, clonic seizure and peculiarly coarse, sparse and colorless scalp hair. These clinical findings can be explained by a dysfunction of the copper-dependent enzymes

  4. Magnetization transfer changes of grey and white matter in Parkinson's disease

    International Nuclear Information System (INIS)

    Tambasco, N.; Mancini, M.L.; Paciaroni, M.; Gallai, V.; Pelliccioli, G.P.; Chiarini, P.; Leone, F.; Montanari, G.E.

    2003-01-01

    Since the attempt to evidence structural brain damage in Parkinson's disease (PD) by conventional magnetic resonance imaging (MRI) is usually disappointing, we have investigated whether the magnetization transfer ratio (MTR) can reflect changes in grey and white matter of PD patients. MTR was quantified in 44 regions of interest (ROIs) in both grey and white matter of 11 non-demented PD patients, ranging from 2 to 4 on the Hoehn and Yahr Scale, and eight age-matched healthy subjects. MTR differences between patients and controls were found in the supratentorial white matter and in the brainstem. In particular, lower MTR values were found in the paraventricular white matter of PD patients (p < 0.05) while no differences were observed in corpus callosum, frontal, parietal, occipital lobes or centrum semiovalis. Lower MTR values were found in substantia nigra (p < 0.001), red nucleus (p < 0.05) and pons (p < 0.05) of the patient group. No differences were discovered in basal ganglia and thalamus. These findings suggest that MTR measurements in the paraventricular white matter and brainstem may help to recognize a marker for probable PD. (orig.)

  5. Characterization of neurons in the cortical white matter in human temporal lobe epilepsy.

    Science.gov (United States)

    Richter, Zsófia; Janszky, József; Sétáló, György; Horváth, Réka; Horváth, Zsolt; Dóczi, Tamás; Seress, László; Ábrahám, Hajnalka

    2016-10-01

    The aim of the present work was to characterize neurons in the archi- and neocortical white matter, and to investigate their distribution in mesial temporal sclerosis. Immunohistochemistry and quantification of neurons were performed on surgically resected tissue sections of patients with therapy-resistant temporal lobe epilepsy. Temporal lobe tissues of patients with tumor but without epilepsy and that from autopsy were used as controls. Neurons were identified with immunohistochemistry using antibodies against NeuN, calcium-binding proteins, transcription factor Tbr1 and neurofilaments. We found significantly higher density of neurons in the archi- and neocortical white matter of patients with temporal lobe epilepsy than in that of controls. Based on their morphology and neurochemical content, both excitatory and inhibitory cells were present among these neurons. A subset of neurons in the white matter was Tbr-1-immunoreactive and these neurons coexpressed NeuN and neurofilament marker SMI311R. No colocalization of Tbr1 was observed with the inhibitory neuronal markers, calcium-binding proteins. We suggest that a large population of white matter neurons comprises remnants of the subplate. Furthermore, we propose that a subset of white matter neurons was arrested during migration, highlighting the role of cortical maldevelopment in epilepsy associated with mesial temporal sclerosis. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  6. Age-related changes of diffusional anisotropy in the cerebral white matter in normal subjects

    International Nuclear Information System (INIS)

    Hanyu, Haruo; Asano, Tetsuichi; Ogawa, Kimikazu; Takasaki, Masaru; Shindo, Hiroaki; Kakizaki, Dai; Abe, Kimihiko

    1997-01-01

    To investigate age-related changes of diffusional anisotropy in the cerebral white matter, we performed diffusion-weighted MRI studies in 21 normal subjects aged 25 to 96 years. The anisotropic rations (ARs), defined as the apparent diffusion coefficients perpendicular to the nerve fibers to those parallel to the nerve fibers, were significantly higher in elderly than in young subjects in the anterior and posterior white matter surrounding the lateral ventricle. Moreover, significant correlation between age and AR was found in the anterior white matter. The ventricular index (VI) measured on MRI, as a quantitative indicator of brain atrophy, was significantly higher in elderly than younger subjects, and significantly correlated with AR in the anterior white matter. Multiple regression analysis demonstrated that the VI showed the highest correlation for AR. On the other hand, there was no significant correlations between ARs in the corpus callosum and age. These results suggest that morphological changes in the myelin and axon in the white matter occur in elderly normal subjects, probably due to neuronal loss with aging. (author)

  7. Preliminary study of normal changes in brain white matter during childhood with diffusion tensor imaging

    International Nuclear Information System (INIS)

    Xiao Jiangxi; Guo Xuemei; Xie Sheng; Wang Xiaoying; Jiang Xuexiang

    2005-01-01

    Objective: To study the normal changes in brain white matter during childhood by analyzing the anisotropy of different regions and different age groups with diffusion tensor imaging (DTI). Methods: DTI was performed in 89 children (age range from 2 days to 18 years) without brain abnormalities, and the data measured in fractional anisotropy (FA) maps were analyzed statistically. Children less than 6 months were ranged to group 1, 6-12 months to group 2, 1-3 years to group 3, 3-5 years to group 4, 5-8 years to group 5, 8-12 years to group 6, 12-18 years to group 7. Results: (1) There were significant differences in anisotropy (FA values) among different regions of white matter in brain. In group 7, the FA value of corpus callosum was 0.826 ± 0.039, middle cerebellar peduncle 0.678 ± 0.043, frontal white matter 0.489 ± 0.033. (2) The anisotropy among different age group was statistically different, P<0.05. (3) The anisotropy of white matter increased with the increasing of age, and FA values showed positively exponentially correlations with age. Conclusion: DTI shows the structure of white matters in vivo, with which normal changes in brain during childhood can be evaluated. (authors)

  8. Executive dysfunctions in migraine with and without aura: what is the role of white matter lesions?

    Science.gov (United States)

    Le Pira, Francesco; Reggio, Ester; Quattrocchi, Graziella; Sanfilippo, Cristina; Maci, Tiziana; Cavallaro, Tiziana; Zappia, Mario

    2014-01-01

    Executive dysfunctions and white matter lesions on magnetic resonance imaging have been reported in migraine. The aim of this study was to determine whether any correlation between these 2 variables exists. Forty-four subjects affected by migraine with or without aura were compared with 16 healthy subjects. A battery of neuropsychological tests assessing executive functions was administered to all subjects. Number and total volume of white matter lesions were assessed in the whole brain and in the frontal lobe. The performances of both groups of migraineurs, with and without aura, were significantly worse when compared with controls on Boston Scanning Test. Moreover, we found lower performances compared with controls respectively on Frontal Assessment Battery in patients with migraine with aura and on Controlled Oral Word Association Test in patients with migraine without aura. Nineteen patients (43.2%) and one control subject (6.2%) had white matter lesions. We did not find any significant correlation between white matter lesions load and neuropsychological performances. On the basis of our results, white matter lesions load on magnetic resonance imaging do not seem to contribute to neuropsychological performances deficit in migraineurs. © 2013 American Headache Society.

  9. Anterior temporal white matter lesions in myotonic dystrophy with intellectual impairment: an MRI and neuropathological study

    International Nuclear Information System (INIS)

    Ogata, A.; Tashiro, K.; Terae, S.; Fujita, M.

    1998-01-01

    We studied 12 patients with myotonic dystrophy using MRI and the Mini-mental state examination (MMSE), to see it specific MRI findings were associated with intellectual impairment. We also compared them with the neuropathological findings in an autopsy case of MD with intellectual impairment. Mild intellectual impairment was found in 8 of the 12 patients. On T 2-weighted and proton density-weighted images, high-intensity areas were seen in cerebral white matter in 10 of the 12 patients. In seven of these, anterior temporal white-matter lesions (ATWML) were found; all seven had mild intellectual impairment (MMSE 22-26), whereas none of the four patients with normal mentation had ATWML. In only one of the eight patients with intellectual impairment were white-matter lesions not found. Pathological findings were severe loss and disordered arrangement of myelin sheaths and axons in addition to heterotopic neurons within anterior temporal white matter. Bilateral ATWML might be a factor for intellectual impairment in MD. The retrospective pathological study raised the possibility that the ATWML are compatible with focal dysplasia of white matter. (orig.)

  10. Cognitive processing speed in older adults: relationship with white matter integrity.

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    Geoffrey A Kerchner

    Full Text Available Cognitive processing slows with age. We sought to determine the importance of white matter integrity, assessed by diffusion tensor imaging (DTI, at influencing cognitive processing speed among normal older adults, assessed using a novel battery of computerized, non-verbal, choice reaction time tasks. We studied 131 cognitively normal adults aged 55-87 using a cross-sectional design. Each participant underwent our test battery, as well as MRI with DTI. We carried out cross-subject comparisons using tract-based spatial statistics. As expected, reaction time slowed significantly with age. In diffuse areas of frontal and parietal white matter, especially the anterior corpus callosum, fractional anisotropy values correlated negatively with reaction time. The genu and body of the corpus callosum, superior longitudinal fasciculus, and inferior fronto-occipital fasciculus were among the areas most involved. This relationship was not explained by gray or white matter atrophy or by white matter lesion volume. In a statistical mediation analysis, loss of white matter integrity mediated the relationship between age and cognitive processing speed.

  11. Usefulness of Diffusion Tensor Imaging of White Matter in Alzheimer Disease and Vascular Dementia

    International Nuclear Information System (INIS)

    Sugihara, S.; Kinoshita, T.; Matsusue, E.; Fujii, S.; Ogawa, T.

    2004-01-01

    Purpose: To evaluate the usefulness of diffusion tensor imaging in detecting the water diffusivity caused by neuro pathological change in Alzheimer disease and vascular dementia. Material and Methods: Twenty patients with Alzheimer disease, 20 with vascular dementia, and 10 control subjects were examined. Diffusion tensor imaging applied diffusion gradient encoding in six non-collinear directions. Fractional anisotropy values were compared in the genu and splenium of the corpus callosum, and anterior and posterior white matter among the three groups. Results: In the patients with Alzheimer disease, fractional anisotropy values of the posterior white matter were significantly lower than those of controls. In patients with vascular dementia, fractional anisotropy values of the anterior white matter tended to be lower than those of the posterior white matter (P=0.07). Conclusion: Diffusion tensor imaging reflects the neuro pathological changes in the white matter, and may be useful in the diagnosis of Alzheimer disease and vascular dementia. Keywords: Alzheimer disease, .; diffusion tensor imaging, .; vascular dementia

  12. Mapping White Matter Integrity and Neurobehavioral Correlates in Children with Fetal Alcohol Spectrum Disorders

    Science.gov (United States)

    Sowell, Elizabeth R.; Johnson, Arianne; Kan, Eric; Lu, Lisa H.; Van Horn, John Darrell; Toga, Arthur W.; O’Connor, Mary J.; Bookheimer, Susan Y.

    2013-01-01

    Brain structural abnormalities and neurocognitive dysfunction have been observed in individuals with fetal alcohol spectrum disorders (FASDs). Little is known about how white matter integrity is related to these functional and morphological deficits. We used a combination of diffusion tensor and T1-weighted magnetic resonance imaging to evaluate white matter integrity in individuals with FASDs and related these findings to neurocognitive deficits. Seventeen children and adolescents with FASDs were compared with 19 typically developing age-and gender-matched controls. Lower fractional anisotropy (FA) was observed in individuals with FASDs relative to controls in the right lateral temporal lobe and bilaterally in the lateral aspects of the splenium of the corpus callosum. White matter density was also lower in some, but not all regions in which FA was lower. FA abnormalities were confirmed to be in areas of white matter in post hoc region of interest analyses, further supporting that less myelin or disorganized fiber tracts are associated with heavy prenatal alcohol exposure. Significant correlations between performance on a test of visuomotor integration and FA in bilateral splenium, but not temporal regions were observed within the FASD group. Correlations between the visuomotor task and FA within the splenium were not significant with in the control group, and were not significant for measures of reading ability. This suggests that this region of white matter is particularly susceptible to damage from prenatal alcohol exposure and that disruption of splenial fibers in this group is associated with poorer visuomotor integration. PMID:18256251

  13. Left hemisphere fractional anisotropy increase in noise-induced tinnitus: a diffusion tensor imaging (DTI) study of white matter tracts in the brain.

    Science.gov (United States)

    Benson, Randall R; Gattu, Ramtilak; Cacace, Anthony T

    2014-03-01

    Diffusion tensor imaging (DTI) is a contemporary neuroimaging modality used to study connectivity patterns and microstructure of white matter tracts in the brain. The use of DTI in the study of tinnitus is a relatively unexplored methodology with no studies focusing specifically on tinnitus induced by noise exposure. In this investigation, participants were two groups of adults matched for etiology, age, and degree of peripheral hearing loss, but differed by the presence or absence (+/-) of tinnitus. It is assumed that matching individuals on the basis of peripheral hearing loss, allows for differentiating changes in white matter microstructure due to hearing loss from changes due to the effects of chronic tinnitus. Alterations in white matter tracts, using the fractional anisotropy (FA) metric, which measures directional diffusion of water, were quantified using tract-based spatial statistics (TBSS) with additional details provided by in vivo probabilistic tractography. Our results indicate that 10 voxel clusters differentiated the two groups, including 9 with higher FA in the group with tinnitus. A decrease in FA was found for a single cluster in the group with tinnitus. However, seven of the 9 clusters with higher FA were in left hemisphere thalamic, frontal, and parietal white matter. These foci were localized to the anterior thalamic radiations and the inferior and superior longitudinal fasciculi. The two right-sided clusters with increased FA were located in the inferior fronto-occipital fasciculus and superior longitudinal fasciculus. The only decrease in FA for the tinnitus-positive group was found in the superior longitudinal fasciculus of the left parietal lobe. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Episodic memory in detoxified alcoholics: contribution of grey matter microstructure alteration.

    Directory of Open Access Journals (Sweden)

    Sandra Chanraud

    Full Text Available Even though uncomplicated alcoholics may likely have episodic memory deficits, discrepancies exist regarding to the integrity of brain regions that underlie this function in healthy subjects. Possible relationships between episodic memory and 1 brain microstructure assessed by magnetic resonance diffusion tensor imaging (DTI, 2 brain volumes assessed by voxel-based morphometry (VBM were investigated in uncomplicated, detoxified alcoholics.Diffusion and morphometric analyses were performed in 24 alcohol dependent men without neurological or somatic complications and in 24 healthy men. The mean apparent coefficient of diffusion (ADC and grey matter volumes were measured in the whole brain. Episodic memory performance was assessed using a French version of the Free and Cued Selective Reminding Test (FCSRT. Correlation analyses between verbal episodic memory, brain microstructure, and brain volumes were carried out using SPM2 software.In those with alcohol dependence, higher ADC was detected mainly in frontal, temporal and parahippocampal regions, and in the cerebellum. In alcoholics, regions with higher ADC typically also had lower grey matter volume. Low verbal episodic memory performance in alcoholism was associated with higher mean ADC in parahippocampal areas, in frontal cortex and in the left temporal cortex; no correlation was found between regional volumes and episodic memory scores. Regression analyses for the control group were not significant.These findings support the hypothesis that regional microstructural but no macrostructural alteration of the brain might be responsible, at least in part, for episodic memory deficits in alcohol dependence.

  15. White and Black Teachers' Job Satisfaction: Does Relational Demography Matter?

    Science.gov (United States)

    Fairchild, Susan; Tobias, Robert; Corcoran, Sean; Djukic, Maja; Kovner, Christine; Noguera, Pedro

    2012-01-01

    Data on the impact of student, teacher, and principal racial and gender composition in urban schools on teacher work outcomes are limited. This study, a secondary data analysis of White and Black urban public school teachers using data taken from the restricted use 2003-04 Schools and Staffing Survey (SASS), examines the effects of relational…

  16. Relative signal intensity changes of frontal and occipital white matters on T 2 weighted axial MR image : correlation with age

    International Nuclear Information System (INIS)

    Kim, You Me; Kim, Seung Cheol

    1998-01-01

    The purpose of this study is to assess relative signal intensity changes in frontal and occipital white matter with age, as seen on T 2 weighted axial MR images. Thirty eight normal adults (20-29 years old) and 114 children (0-11 years old) were investigated. All had nonspecific neurologic symptoms and their MR images, obtained using a 1.5 T system (Signa, GE Medical Systems, Milwaukee, U.S.A.), appeared to be normal. The signal intensities of frontal and occipital white matter were evaluated on T2 weighted axial images at the level of the foramen of Monro. When the signal intensity of white matter was higher than that of gray matter, grade 0 was assigned; when the opposite situation pertained, this was graded I - III. Grade I indicated that the signal intensity of occipital white matter was lower than that of frontal white matter; grade II, that the signal intensity of white matter of both lobes was similar. When the signal intensity of frontal white matter was lower than that of occipital age, and by one year after 2 years of age, and then determined grade according to age, age distribution according to grade, and the ages at which signal intensities were similar to those of adults. On T2-weighted MR images, the signal intensity of frontal white matter ultimately shows a lower signal intensity than that of occipital white matter. (author). 11 refs., 6 figs

  17. White versus gray matter function as seen on neuropsychological testing following bone marrow transplant for acute leukemia in childhood

    Directory of Open Access Journals (Sweden)

    Fiona S Anderson

    2008-03-01

    Full Text Available Fiona S Anderson1, Alicia S Kunin-Batson1, Joanna L Perkins2, K Scott Baker31Divisions of Pediatric Clinical Neuroscience; 2Department of Pediatric Hematology/Oncology, Children’s Hospitals and Clinics, Minneapolis, MN, USA and 3Hematology/Oncology/BMT, Department of Pediatrics, University of Minnesota, Minneapolis, MN, USAAbstract: Current theory suggests that neurocognitive late effects of treatments for childhood cancer such as difficulties with attention, processing speed and visual-motor ability are the result of white matter damage. Neuroimaging studies have produced a variety of white matter findings. However, although white matter is thought to be differentially affected, previous studies have not demonstrated a discrepancy between white and gray matter function. The present study included 36 children treated for childhood leukemia with hematopoietic stem cell transplant (HCT. Their performance on neurocognitive measures traditionally thought to measure white matter was compared to performance on measures thought to measure gray matter function. Composite white and gray matter standard scores were created based on neuropsychological measures that individuals with known white or gray matter damage perform poorly. As predicted, composite white matter scores (mean = 98.1 were significantly lower (t = 2.26, p = 0.03 than composite gray matter scores (mean = 102.5. Additionally, as gray matter performance increased, the difference between gray and white matter scores increased (R = 0.353, p = 0.035. Overall, the results of this study support the current theory that white matter damage is responsible for the more subtle neurocognitive late effects resulting from treatment for childhood leukemia.Keywords: late effects of cancer treatment, leukemia, neuropsychology, white matter, brain function

  18. The hidden-Markov brain: comparison and inference of white matter hyperintensities on magnetic resonance imaging (MRI)

    Science.gov (United States)

    Pham, Tuan D.; Salvetti, Federica; Wang, Bing; Diani, Marco; Heindel, Walter; Knecht, Stefan; Wersching, Heike; Baune, Bernhard T.; Berger, Klaus

    2011-02-01

    Rating and quantification of cerebral white matter hyperintensities on magnetic resonance imaging (MRI) are important tasks in various clinical and scientific settings. As manual evaluation is time consuming and imprecise, much effort has been made to automate the quantification of white matter hyperintensities. There is rarely any report that attempts to study the similarity/dissimilarity of white matter hyperintensity patterns that have different sizes, shapes and spatial localizations on the MRI. This paper proposes an original computational neuroscience framework for such a conceptual study with a standpoint that the prior knowledge about white matter hyperintensities can be accumulated and utilized to enable a reliable inference of the rating of a new white matter hyperintensity observation. This computational approach for rating inference of white matter hyperintensities, which appears to be the first study, can be utilized as a computerized rating-assisting tool and can be very economical for diagnostic evaluation of brain tissue lesions.

  19. Diffusion-tensor MR imaging of gray and white matter development during normal human brain maturation.

    Science.gov (United States)

    Mukherjee, Pratik; Miller, Jeffrey H; Shimony, Joshua S; Philip, Joseph V; Nehra, Deepika; Snyder, Abraham Z; Conturo, Thomas E; Neil, Jeffrey J; McKinstry, Robert C

    2002-10-01

    Conventional MR imaging findings of human brain development are thought to result from decreasing water content, increasing macromolecular concentration, and myelination. We use diffusion-tensor MR imaging to test theoretical models that incorporate hypotheses regarding how these maturational processes influence water diffusion in developing gray and white matter. Experimental data were derived from diffusion-tensor imaging of 167 participants, ages 31 gestational weeks to 11 postnatal years. An isotropic diffusion model was applied to the gray matter of the basal ganglia and thalamus. A model that assumes changes in the magnitude of diffusion while maintaining cylindrically symmetric anisotropy was applied to the white matter of the corpus callosum and internal capsule. Deviations of the diffusion tensor from the ideal model predictions, due to measurement noise, were estimated by using Monte Carlo simulations. Developing gray matter of the basal ganglia and developing white matter of the internal capsule and corpus callosum largely conformed to theory, with only small departures from model predictions in older children. However, data from the thalamus substantially diverged from predicted values, with progressively larger deviations from the model with increasing participant age. Changes in water diffusion during maturation of central gray and white matter structures can largely be explained by theoretical models incorporating simple assumptions regarding the influence of brain water content and myelination, although deviations from theory increase as the brain matures. Diffusion-tensor MR imaging is a powerful method for studying the process of brain development, with both scientific and clinical applications.

  20. Preclinical cerebral network connectivity evidence of deficits in mild white matter lesions

    Directory of Open Access Journals (Sweden)

    Ying eLiang

    2016-02-01

    Full Text Available White matter lesions (WMLs are notable for their high prevalence and have been demonstrated to be a potential neuroimaging biomarker of early diagnosis of Alzheimer’s disease. This study aimed to identify the brain functional and structural mechanisms underlying cognitive decline observed in mild WMLs. Multi-domain cognitive tests, as well as resting-state, diffusion tensor and structural images were obtained on 42 mild WMLs and 42 age/sex-matched healthy controls. For each participant, we examined the functional connectivity of three resting-state networks related to the changed cognitive domains: the default mode network (DMN and the bilateral fronto-parietal network (FPN. We also performed voxel-based morphometry analysis to compare whole-brain gray matter volume, atlas-based quantification of the white matter tracts interconnecting the RSNs, and the relationship between functional connectivity and structural connectivity. We observed functional connectivity alterations in the DMN and the right FPN combined with related white matter integrity disruption in mild WMLs. However, no significant gray matter atrophy difference was found. Furthermore, the right precuneus functional connectivity in the DMN exhibited a significantly negative correlation with the memory test scores. Our study suggests that in mild WMLs, dysfunction of RSNs might be a consequence of decreased white matter structural connectivity, which further affects cognitive performance.

  1. Analysis of the brain proton magnetic resonance spectroscopy - differences between normal grey and white matter

    International Nuclear Information System (INIS)

    Krukowski, P.; Podgorski, P.; Guzinski, M.; Szewczyk, P.; Sasiadek, M.

    2010-01-01

    Background: The proton magnetic resonance spectroscopy (HMRS) is a non-invasive diagnostic method that allows for an assessment of the metabolite concentration in tissues. The sources of the strongest resonance signals within the brain are N-acetylaspartate (NAA), creatine (Cr), choline (Cho), myoinositol (mI) and water. The aim of our study was to analyse the ratios of metabolite signals within the brain in HMRS in the healthy population, to define the differences between the grey and white matter spectra. Material/Methods: We studied prospectively 90 subjects aged from 8 to 80 years (mean 43.3 years, SD=17.9), without neurological symptoms or abnormalities in magnetic resonance imaging. In all patients, brain HMRS with Signa HDx 1.5 T MR unit (GE Healthcare) was performed with PRESS sequence, using a single voxel method, at TE of 35 ms and TR of 1500 ms. Spectroscopic evaluation involved voxels placed in the white matter of parietal lobe (PWM) and the grey matter of posterior cingulate gyrus (PGM). On the basis of the intensity of NAA, Cr, Cho, mI and water signals, the proportions of these signals were calculated, as well as the ratio of the analyzed metabolite signal to the sum of signals of NAA, Cho, Cr and mI (%Met) in the PGM and PWM voxels. We compared the proportions in the same patients in PGM and PWM voxels. Results: There has been a statistically significant difference between the proportions of a majority of the metabolite ratios evaluated in PGM and PWM, indicating the higher concentration of NAA, Cr and mI in grey matter, and higher concentration of Cho in white matter. Conclusions: HMRS spectra of the brain grey and white matter differ significantly. The concentrations of NAA, Cr and mI are higher in grey matter, while of choline - in the white matter. (authors)

  2. White matter impairments in autism, evidence from voxel-based morphometry and diffusion tensor imaging.

    Science.gov (United States)

    Ke, Xiaoyan; Tang, Tianyu; Hong, Shanshan; Hang, Yueyue; Zou, Bing; Li, Huiguo; Zhou, Zhenyu; Ruan, Zongcai; Lu, Zuhong; Tao, Guotai; Liu, Yijun

    2009-04-10

    This study explored white matter abnormalities in a group of Chinese children with high functioning autism (HFA). Twelve male children with HFA and ten matched typically developing children underwent diffusion tensor imaging (DTI) as well three-dimensional T1-weighted MRI for voxel-based morphometry (VBM). We found a significant decrease of the white matter density in the right frontal lobe, left parietal lobe and right anterior cingulate and a significant increase in the right frontal lobe, left parietal lobe and left cingulate gyrus in the HFA group compared with the control group. The HFA group also had decreased FA in the frontal lobe and left temporal lobe. By combining DT-MRI FA and MRI volumetric analyses based on the VBM model, the results showed consistent white matter abnormalities in a group of Chinese children with HFA.

  3. Frontal white matter hyperintensities, clasmatodendrosis and gliovascular abnormalities in ageing and post-stroke dementia.

    Science.gov (United States)

    Chen, Aiqing; Akinyemi, Rufus O; Hase, Yoshiki; Firbank, Michael J; Ndung'u, Michael N; Foster, Vincent; Craggs, Lucy J L; Washida, Kazuo; Okamoto, Yoko; Thomas, Alan J; Polvikoski, Tuomo M; Allan, Louise M; Oakley, Arthur E; O'Brien, John T; Horsburgh, Karen; Ihara, Masafumi; Kalaria, Raj N

    2016-01-01

    White matter hyperintensities as seen on brain T2-weighted magnetic resonance imaging are associated with varying degrees of cognitive dysfunction in stroke, cerebral small vessel disease and dementia. The pathophysiological mechanisms within the white matter accounting for cognitive dysfunction remain unclear. With the hypothesis that gliovascular interactions are impaired in subjects with high burdens of white matter hyperintensities, we performed clinicopathological studies in post-stroke survivors, who had exhibited greater frontal white matter hyperintensities volumes that predicted shorter time to dementia onset. Histopathological methods were used to identify substrates in the white matter that would distinguish post-stroke demented from post-stroke non-demented subjects. We focused on the reactive cell marker glial fibrillary acidic protein (GFAP) to study the incidence and location of clasmatodendrosis, a morphological attribute of irreversibly injured astrocytes. In contrast to normal appearing GFAP+ astrocytes, clasmatodendrocytes were swollen and had vacuolated cell bodies. Other markers such as aldehyde dehydrogenase 1 family, member L1 (ALDH1L1) showed cytoplasmic disintegration of the astrocytes. Total GFAP+ cells in both the frontal and temporal white matter were not greater in post-stroke demented versus post-stroke non-demented subjects. However, the percentage of clasmatodendrocytes was increased by >2-fold in subjects with post-stroke demented compared to post-stroke non-demented subjects (P = 0.026) and by 11-fold in older controls versus young controls (P < 0.023) in the frontal white matter. High ratios of clasmotodendrocytes to total astrocytes in the frontal white matter were consistent with lower Mini-Mental State Examination and the revised Cambridge Cognition Examination scores in post-stroke demented subjects. Double immunofluorescent staining showed aberrant co-localization of aquaporin 4 (AQP4) in retracted GFAP+ astrocytes with

  4. The nature of white matter abnormalities in blast-related mild traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Jasmeet P. Hayes

    2015-01-01

    Full Text Available Blast-related traumatic brain injury (TBI has been a common injury among returning troops due to the widespread use of improvised explosive devices in the Iraq and Afghanistan Wars. As most of the TBIs sustained are in the mild range, brain changes may not be detected by standard clinical imaging techniques such as CT. Furthermore, the functional significance of these types of injuries is currently being debated. However, accumulating evidence suggests that diffusion tensor imaging (DTI is sensitive to subtle white matter abnormalities and may be especially useful in detecting mild TBI (mTBI. The primary aim of this study was to use DTI to characterize the nature of white matter abnormalities following blast-related mTBI, and in particular, examine the extent to which mTBI-related white matter abnormalities are region-specific or spatially heterogeneous. In addition, we examined whether mTBI with loss of consciousness (LOC was associated with more extensive white matter abnormality than mTBI without LOC, as well as the potential moderating effect of number of blast exposures. A second aim was to examine the relationship between white matter integrity and neurocognitive function. Finally, a third aim was to examine the contribution of PTSD symptom severity to observed white matter alterations. One hundred fourteen OEF/OIF veterans underwent DTI and neuropsychological examination and were divided into three groups including a control group, blast-related mTBI without LOC (mTBI - LOC group, and blast-related mTBI with LOC (mTBI + LOC group. Hierarchical regression models were used to examine the extent to which mTBI and PTSD predicted white matter abnormalities using two approaches: 1 a region-specific analysis and 2 a measure of spatial heterogeneity. Neurocognitive composite scores were calculated for executive functions, attention, memory, and psychomotor speed. Results showed that blast-related mTBI + LOC was associated with greater odds of

  5. White matter abnormalities in gene-positive myoclonus-dystonia

    NARCIS (Netherlands)

    van der Meer, Johan N.; Beukers, Richard J.; van der Salm, S. M. A.; Caan, Matthan W. A.; Tijssen, Marina A. J.; Nederveen, Aart J.

    2012-01-01

    Myoclonus-dystonia is an autosomal dominantly inherited movement disorder clinically characterized by myoclonic jerks and dystonic movements of the upper body. Functional imaging and structural gray matter imaging studies in M-D suggest defective sensorimotor integration and an association between

  6. AxTract: Toward microstructure informed tractography.

    Science.gov (United States)

    Girard, Gabriel; Daducci, Alessandro; Petit, Laurent; Thiran, Jean-Philippe; Whittingstall, Kevin; Deriche, Rachid; Wassermann, Demian; Descoteaux, Maxime

    2017-11-01

    Diffusion-weighted (DW) magnetic resonance imaging (MRI) tractography has become the tool of choice to probe the human brain's white matter in vivo. However, tractography algorithms produce a large number of erroneous streamlines (false positives), largely due to complex ambiguous tissue configurations. Moreover, the relationship between the resulting streamlines and the underlying white matter microstructure characteristics remains poorly understood. In this work, we introduce a new approach to simultaneously reconstruct white matter fascicles and characterize the apparent distribution of axon diameters within fascicles. To achieve this, our method, AxTract, takes full advantage of the recent development DW-MRI microstructure acquisition, modeling, and reconstruction techniques. This enables AxTract to separate parallel fascicles with different microstructure characteristics, hence reducing ambiguities in areas of complex tissue configuration. We report a decrease in the incidence of erroneous streamlines compared to the conventional deterministic tractography algorithms on simulated data. We also report an average increase in streamline density over 15 known fascicles of the 34 healthy subjects. Our results suggest that microstructure information improves tractography in crossing areas of the white matter. Moreover, AxTract provides additional microstructure information along the fascicle that can be studied alongside other streamline-based indices. Overall, AxTract provides the means to distinguish and follow white matter fascicles using their microstructure characteristics, bringing new insights into the white matter organization. This is a step forward in microstructure informed tractography, paving the way to a new generation of algorithms able to deal with intricate configurations of white matter fibers and providing quantitative brain connectivity analysis. Hum Brain Mapp 38:5485-5500, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  7. Seven-Tesla Magnetization Transfer Imaging to Detect Multiple Sclerosis White Matter Lesions.

    Science.gov (United States)

    Chou, I-Jun; Lim, Su-Yin; Tanasescu, Radu; Al-Radaideh, Ali; Mougin, Olivier E; Tench, Christopher R; Whitehouse, William P; Gowland, Penny A; Constantinescu, Cris S

    2018-03-01

    Fluid-attenuated inversion recovery (FLAIR) imaging at 3 Tesla (T) field strength is the most sensitive modality for detecting white matter lesions in multiple sclerosis. While 7T FLAIR is effective in detecting cortical lesions, it has not been fully optimized for visualization of white matter lesions and thus has not been used for delineating lesions in quantitative magnetic resonance imaging (MRI) studies of the normal appearing white matter in multiple sclerosis. Therefore, we aimed to evaluate the sensitivity of 7T magnetization-transfer-weighted (MT w ) images in the detection of white matter lesions compared with 3T-FLAIR. Fifteen patients with clinically isolated syndrome, 6 with multiple sclerosis, and 10 healthy participants were scanned with 7T 3-dimensional (D) MT w and 3T-2D-FLAIR sequences on the same day. White matter lesions visible on either sequence were delineated. Of 662 lesions identified on 3T-2D-FLAIR images, 652 were detected on 7T-3D-MT w images (sensitivity, 98%; 95% confidence interval, 97% to 99%). The Spearman correlation coefficient between lesion loads estimated by the two sequences was .910. The intrarater and interrater reliability for 7T-3D-MT w images was good with an intraclass correlation coefficient (ICC) of 98.4% and 81.8%, which is similar to that for 3T-2D-FLAIR images (ICC 96.1% and 96.7%). Seven-Tesla MT w sequences detected most of the white matter lesions identified by FLAIR at 3T. This suggests that 7T-MT w imaging is a robust alternative for detecting demyelinating lesions in addition to 3T-FLAIR. Future studies need to compare the roles of optimized 7T-FLAIR and of 7T-MT w imaging. © 2017 The Authors. Journal of Neuroimaging published by Wiley Periodicals, Inc. on behalf of American Society of Neuroimaging.

  8. Whole genome grey and white matter DNA methylation profiles in dorsolateral prefrontal cortex.

    Science.gov (United States)

    Sanchez-Mut, Jose Vicente; Heyn, Holger; Vidal, Enrique; Delgado-Morales, Raúl; Moran, Sebastian; Sayols, Sergi; Sandoval, Juan; Ferrer, Isidre; Esteller, Manel; Gräff, Johannes

    2017-06-01

    The brain's neocortex is anatomically organized into grey and white matter, which are mainly composed by neuronal and glial cells, respectively. The neocortex can be further divided in different Brodmann areas according to their cytoarchitectural organization, which are associated with distinct cortical functions. There is increasing evidence that brain development and function are governed by epigenetic processes, yet their contribution to the functional organization of the neocortex remains incompletely understood. Herein, we determined the DNA methylation patterns of grey and white matter of dorsolateral prefrontal cortex (Brodmann area 9), an important region for higher cognitive skills that is particularly affected in various neurological diseases. For avoiding interindividual differences, we analyzed white and grey matter from the same donor using whole genome bisulfite sequencing, and for validating their biological significance, we used Infinium HumanMethylation450 BeadChip and pyrosequencing in ten and twenty independent samples, respectively. The combination of these analysis indicated robust grey-white matter differences in DNA methylation. What is more, cell type-specific markers were enriched among the most differentially methylated genes. Interestingly, we also found an outstanding number of grey-white matter differentially methylated genes that have previously been associated with Alzheimer's, Parkinson's, and Huntington's disease, as well as Multiple and Amyotrophic lateral sclerosis. The data presented here thus constitute an important resource for future studies not only to gain insight into brain regional as well as grey and white matter differences, but also to unmask epigenetic alterations that might underlie neurological and neurodegenerative diseases. © 2017 Wiley Periodicals, Inc.

  9. White matter tract signatures of impaired social cognition in frontotemporal lobar degeneration

    Directory of Open Access Journals (Sweden)

    Laura E. Downey

    2015-01-01

    Full Text Available Impairments of social cognition are often leading features in frontotemporal lobar degeneration (FTLD and likely to reflect large-scale brain network disintegration. However, the neuroanatomical basis of impaired social cognition in FTLD and the role of white matter connections have not been defined. Here we assessed social cognition in a cohort of patients representing two core syndromes of FTLD, behavioural variant frontotemporal dementia (bvFTD; n = 29 and semantic variant primary progressive aphasia (svPPA; n = 15, relative to healthy older individuals (n = 37 using two components of the Awareness of Social Inference Test, canonical emotion identification and sarcasm identification. Diffusion tensor imaging (DTI was used to derive white matter tract correlates of social cognition performance and compared with the distribution of grey matter atrophy on voxel-based morphometry. The bvFTD and svPPA groups showed comparably severe deficits for identification of canonical emotions and sarcasm, and these deficits were correlated with distributed and overlapping white matter tract alterations particularly affecting frontotemporal connections in the right cerebral hemisphere. The most robust DTI associations were identified in white matter tracts linking cognitive and evaluative processing with emotional responses: anterior thalamic radiation, fornix (emotion identification and uncinate fasciculus (sarcasm identification. DTI associations of impaired social cognition were more consistent than corresponding grey matter associations. These findings delineate a brain network substrate for the social impairment that characterises FTLD syndromes. The findings further suggest that DTI can generate sensitive and functionally relevant indexes of white matter damage in FTLD, with potential to transcend conventional syndrome boundaries.

  10. Accretion of matter onto white dwarfs as a possible x-ray mechanism

    International Nuclear Information System (INIS)

    DeGregoria, A.J.

    1973-01-01

    Accretion of matter onto white dwarfs is investigated; to see if x-rays are produced; to see what type of radiation spectrum one gets; to see what type of short term time dependent behavior one gets; and, finally, to see how everything varies as the rate of inflow of matter is varied and as the mass and radius of the white dwarf under consideration are varied. The main approximation used is the assumption of spherical symmetry. The motivation behind the investigation is to see how well one can explain the various x-ray sources known

  11. Genetic Schizophrenia Risk Variants Jointly Modulate Total Brain and White Matter Volume

    DEFF Research Database (Denmark)

    Terwisscha van Scheltinga, Afke F; Bakker, Steven C; van Haren, Neeltje E M

    2013-01-01

    with total brain volume (R(2)=.048, p=1.6×10(-4)) and white matter volume (R(2)=.051, p=8.6×10(-5)) equally in patients and control subjects. The number of (independent) SNPs that substantially influenced both disease risk and white matter (n=2020) was much smaller than the entire set of SNPs that modulated...... modulating schizophrenia and brain volume. METHODS: Odds ratios for genome-wide SNP data were calculated in the sample collected by the Psychiatric Genome-wide Association Study Consortium (8690 schizophrenia patients and 11,831 control subjects, excluding subjects from the present study). These were used...

  12. Pathophysiology of white matter perfusion in Alzheimer's disease and vascular dementia.

    Science.gov (United States)

    Barker, Rachel; Ashby, Emma L; Wellington, Dannielle; Barrow, Vivienne M; Palmer, Jennifer C; Kehoe, Patrick G; Esiri, Margaret M; Love, Seth

    2014-05-01

    Little is known about the contributors and physiological responses to white matter hypoperfusion in the human brain. We previously showed the ratio of myelin-associated glycoprotein to proteolipid protein 1 in post-mortem human brain tissue correlates with the degree of ante-mortem ischaemia. In age-matched post-mortem cohorts of Alzheimer's disease (n = 49), vascular dementia (n = 17) and control brains (n = 33) from the South West Dementia Brain Bank (Bristol), we have now examined the relationship between the ratio of myelin-associated glycoprotein to proteolipid protein 1 and several other proteins involved in regulating white matter vascularity and blood flow. Across the three cohorts, white matter perfusion, indicated by the ratio of myelin-associated glycoprotein to proteolipid protein 1, correlated positively with the concentration of the vasoconstrictor, endothelin 1 (P = 0.0005), and negatively with the concentration of the pro-angiogenic protein, vascular endothelial growth factor (P = 0.0015). The activity of angiotensin-converting enzyme, which catalyses production of the vasoconstrictor angiotensin II was not altered. In samples of frontal white matter from an independent (Oxford, UK) cohort of post-mortem brains (n = 74), we confirmed the significant correlations between the ratio of myelin-associated glycoprotein to proteolipid protein 1 and both endothelin 1 and vascular endothelial growth factor. We also assessed microvessel density in the Bristol (UK) samples, by measurement of factor VIII-related antigen, which we showed to correlate with immunohistochemical measurements of vessel density, and found factor VIII-related antigen levels to correlate with the level of vascular endothelial growth factor (P = 0.0487), suggesting that upregulation of vascular endothelial growth factor tends to increase vessel density in the white matter. We propose that downregulation of endothelin 1 and upregulation of vascular endothelial growth factor in the context

  13. White matter magnetic resonance hyperintensities in dementia of the Alzheimer type

    DEFF Research Database (Denmark)

    Waldemar, G; Christiansen, P; Larsson, H B

    1994-01-01

    In a prospective MRI study the presence, appearance, volume, and regional cerebral blood flow (rCBF) correlates of periventricular hyperintensities (PVHs) and deep white matter hyperintensities (DWMHs) were examined in 18 patients with probable Alzheimer's disease and in 10 age matched healthy...... in the Alzheimer's disease group (p ... patients had extensive DWMH lesions in the central white matter. In the group of patients with Alzheimer's disease as a whole, the volume of DWMHs correlated well with rCBF in the hippocampal region ( r = -0.72; p

  14. Enhancement of multiple cranial and spinal nerves in vanishing white matter: expanding the differential diagnosis.

    Science.gov (United States)

    Eluvathingal Muttikkal, Thomas Jose; Montealegre, Denia Ramirez; Matsumoto, Julie Ann

    2018-03-01

    Abnormal cranial or spinal nerve contrast enhancement on MRI in cases of suspected pediatric leukodystrophy is recognized as an important clue to the diagnosis of either metachromatic leukodystrophy or globoid cell leukodystrophy (Krabbe disease). We report a case of genetically confirmed childhood vanishing white matter with enhancement of multiple cranial and spinal nerves in addition to the more typical intracranial findings. This case expands the limited differential diagnosis of cranial nerve or spinal nerve enhancement in cases of suspected leukodystrophy and may aid in more efficient work-up and earlier diagnosis of vanishing white matter.

  15. Relaxation time measurements of white and grey matter in multiple sclerosis patients

    International Nuclear Information System (INIS)

    Rinck, P.A.; Appel, B.; Moens, E.; Academisch Ziekenhuis Middelheim, Antwerp

    1987-01-01

    In a patient population of some 450 with definite, probable, and possible multiple sclerosis referred to us for MRI, some 40 suffering from definite MS were chosen randomly for relaxation time measurements of plaque-free grey and white matter. T 1 values could not be used for diagnostic purposes owing to their broad standard deviation. Overall white matter T 2 was slightly higher in MS patients than in a non-MS population (94 ms versus 89 ms). Because these changes are not visible in MR images, relaxation time measurements may prove valuable for differential diagnosis. (orig.) [de

  16. Aortic stiffness is associated with white matter integrity in patients with type 1 diabetes

    International Nuclear Information System (INIS)

    Tjeerdema, Nathanja; Schinkel, Linda D. van; Westenberg, Jos J.; Elderen, Saskia G. van; Buchem, Mark A. van; Grond, Jeroen van der; Roos, Albert de; Smit, Johannes W.

    2014-01-01

    To assess the association between aortic pulse wave velocity (PWV) as a marker of arterial stiffness and diffusion tensor imaging of brain white matter integrity in patients with type 1 diabetes using advanced magnetic resonance imaging (MRI) technology. Forty-one patients with type 1 diabetes (23 men, mean age 44 ± 12 years, mean diabetes duration 24 ± 13 years) were included. Aortic PWV was assessed using through-plane velocity-encoded MRI. Brain diffusion tensor imaging (DTI) measurements were performed on 3-T MRI. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were calculated for white and grey matter integrity. Pearson correlation and multivariable linear regression analyses including cardiovascular risk factors as covariates were assessed. Multivariable linear regression analyses revealed that aortic PWV is independently associated with white matter integrity FA (β = -0.777, p = 0.008) in patients with type 1 diabetes. This effect was independent of age, gender, mean arterial pressure, body mass index, smoking, duration of diabetes and glycated haemoglobin levels. Aortic PWV was not significantly related to grey matter integrity. Our data suggest that aortic stiffness is independently associated with reduced white matter integrity in patients with type 1 diabetes. (orig.)

  17. Family Income, Cumulative Risk Exposure, and White Matter Structure in Middle Childhood

    Directory of Open Access Journals (Sweden)

    Alexander J. Dufford

    2017-11-01

    Full Text Available Family income is associated with gray matter morphometry in children, but little is known about the relationship between family income and white matter structure. In this paper, using Tract-Based Spatial Statistics, a whole brain, voxel-wise approach, we examined the relationship between family income (assessed by income-to-needs ratio and white matter organization in middle childhood (N = 27, M = 8.66 years. Results from a non-parametric, voxel-wise, multiple regression (threshold-free cluster enhancement, p < 0.05 FWE corrected indicated that lower family income was associated with lower white matter organization [assessed by fractional anisotropy (FA] for several clusters in white matter tracts involved in cognitive and emotional functions including fronto-limbic circuitry (uncinate fasciculus and cingulum bundle, association fibers (inferior longitudinal fasciculus, superior longitudinal fasciculus, and corticospinal tracts. Further, we examined the possibility that cumulative risk (CR exposure might function as one of the potential pathways by which family income influences neural outcomes. Using multiple regressions, we found lower FA in portions of these tracts, including those found in the left cingulum bundle and left superior longitudinal fasciculus, was significantly related to greater exposure to CR (β = -0.47, p < 0.05 and β = -0.45, p < 0.05.

  18. Quantitative MRI assessments of white matter in children treated for acute lymphoblastic leukemia

    Science.gov (United States)

    Reddick, Wilburn E.; Glass, John O.; Helton, Kathleen J.; Li, Chin-Shang; Pui, Ching-Hon

    2005-04-01

    The purpose of this study was to use objective quantitative MR imaging methods to prospectively assess changes in the physiological structure of white matter during the temporal evolution of leukoencephalopathy (LE) in children treated for acute lymphoblastic leukemia. The longitudinal incidence, extent (proportion of white matter affect), and intensity (elevation of T1 and T2 relaxation rates) of LE was evaluated for 44 children. A combined imaging set consisting of T1, T2, PD, and FLAIR MR images and white matter, gray matter and CSF a priori maps from a spatially normalized atlas were analyzed with a neural network segmentation based on a Kohonen Self-Organizing Map (SOM). Quantitative T1 and T2 relaxation maps were generated using a nonlinear parametric optimization procedure to fit the corresponding multi-exponential models. A Cox proportional regression was performed to estimate the effect of intravenous methotrexate (IV-MTX) exposure on the development of LE followed by a generalized linear model to predict the probability of LE in new patients. Additional T-tests of independent samples were performed to assess differences in quantitative measures of extent and intensity at four different points in therapy. Higher doses and more courses of IV-MTX placed patients at a higher risk of developing LE and were associated with more intense changes affecting more of the white matter volume; many of the changes resolved after completion of therapy. The impact of these changes on neurocognitive functioning and quality of life in survivors remains to be determined.

  19. Aortic stiffness is associated with white matter integrity in patients with type 1 diabetes

    Energy Technology Data Exchange (ETDEWEB)

    Tjeerdema, Nathanja; Schinkel, Linda D. van [Leiden University Medical Center, Department of Endocrinology and General Internal Medicine (C7-Q), Albinusdreef 2, PO Box 9600, Leiden (Netherlands); Westenberg, Jos J.; Elderen, Saskia G. van; Buchem, Mark A. van; Grond, Jeroen van der; Roos, Albert de [Leiden University Medical Center, Department of Radiology, Leiden (Netherlands); Smit, Johannes W. [Leiden University Medical Center, Department of Endocrinology and General Internal Medicine (C7-Q), Albinusdreef 2, PO Box 9600, Leiden (Netherlands); University Medical Center Nijmegen, Department of General Internal Medicine, Nijmegen (Netherlands)

    2014-09-15

    To assess the association between aortic pulse wave velocity (PWV) as a marker of arterial stiffness and diffusion tensor imaging of brain white matter integrity in patients with type 1 diabetes using advanced magnetic resonance imaging (MRI) technology. Forty-one patients with type 1 diabetes (23 men, mean age 44 ± 12 years, mean diabetes duration 24 ± 13 years) were included. Aortic PWV was assessed using through-plane velocity-encoded MRI. Brain diffusion tensor imaging (DTI) measurements were performed on 3-T MRI. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were calculated for white and grey matter integrity. Pearson correlation and multivariable linear regression analyses including cardiovascular risk factors as covariates were assessed. Multivariable linear regression analyses revealed that aortic PWV is independently associated with white matter integrity FA (β = -0.777, p = 0.008) in patients with type 1 diabetes. This effect was independent of age, gender, mean arterial pressure, body mass index, smoking, duration of diabetes and glycated haemoglobin levels. Aortic PWV was not significantly related to grey matter integrity. Our data suggest that aortic stiffness is independently associated with reduced white matter integrity in patients with type 1 diabetes. (orig.)

  20. The Black-White achievement gap: Do state policies matter?

    Directory of Open Access Journals (Sweden)

    Henry I. Braun

    2006-03-01

    Full Text Available A longstanding issue in American education is the gap in academic achievement between majority and minority students. The goal of this study is to accumulate and evaluate evidence on the relationship between state education policies and changes in the Black-White achievement gap, while addressing some of the methodological issues that have led to differences in interpretations of earlier findings. To that end, we consider the experiences of ten states that together enroll more than forty percent of the nation's Black students. We estimate the trajectories of Black student and White student achievement on the NAEP 8th grade mathematics assessment over the period 1992 to 2000, and examine the achievement gap at three levels of aggregation: the state as a whole, groups of schools (strata within a state defined by the SES level of the student population, and within schools within a stratum within a state. From 1992 to 2000, at every level of aggregation, mean achievement rose for both Black students and White students. However, for most states the achievement gaps were large and changed very little at every level of aggregation. The gaps are pervasive, profound and persistent. There is substantial heterogeneity among states in the types of policies they pursued, as well as the coherence and consistency of those policies during the period 1988-1998. We find that states' overall policy rankings (based on our review of the data correlate moderately with their record in improving Black student achievement but are somewhat less useful in predicting their record with respect to reducing the achievement gaps. States' rankings on commitment to teacher quality correlate almost as well as did the overall policy ranking. Thus, state reform efforts are a blunt tool, but a tool nonetheless. Our findings are consistent with the following recommendations: states' reform efforts should be built on broad-based support and buffered as much as possible from changes in

  1. Gray and white matter distribution in dyslexia: a VBM study of superior temporal gyrus asymmetry.

    Directory of Open Access Journals (Sweden)

    Marjorie Dole

    Full Text Available In the present study, we investigated brain morphological signatures of dyslexia by using a voxel-based asymmetry analysis. Dyslexia is a developmental disorder that affects the acquisition of reading and spelling abilities and is associated with a phonological deficit. Speech perception disabilities have been associated with this deficit, particularly when listening conditions are challenging, such as in noisy environments. These deficits are associated with known neurophysiological correlates, such as a reduction in the functional activation or a modification of functional asymmetry in the cortical regions involved in speech processing, such as the bilateral superior temporal areas. These functional deficits have been associated with macroscopic morphological abnormalities, which potentially include a reduction in gray and white matter volumes, combined with modifications of the leftward asymmetry along the perisyl