Browsing by Subject "White matter integrity"

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    Comparison of Season-Long Diffusivity Measures in a Cohort of Non-Concussed Contact and Non-Contact Athletes
    (Taylor & Francis, 2020-10) Merz, Zachary C.; Flashman, Laura A.; Ford, James C.; McDonald, Brenna C.; McAllister, Thomas W.; Radiology and Imaging Sciences, School of Medicine
    Introduction: Concern surrounding short- and long-term consequences of participation in contact sports has become a significant public health topic. Previous literature utilizing diffusion tensor imaging in sports-related concussion has exhibited notable variety of analysis methods and analyzed regions of interest, and largely focuses on acute effects of concussion. The current study aimed to compare diffusivity metrics across a single season within athlete cohorts with no history of concussion. Methods: A prospective cohort of 75 contact and 79 non-contact division I athletes were compared across diffusion tensor imaging metrics (i.e. TRACULA); examinations were also performed assessing the relationship between neuroimaging metrics, head impact exposure metrics (in-helmet accelerometer), and neurocognitive variables. Assessment occurred at pre-and post-season time points. Results: Seasonal changes in fractional anisotropy and mean diffusivity values did not differ between athlete cohorts, nor did they differ within cohort groups, across pre- and post-season scans. Specific to contact athletes, positive associations were found between uncinate fasciculus mean diffusivity values and season linear acceleration (p =.018), season rotational acceleration (p =.017), and season hit severity (p =.021). Conclusions: Results suggest an influence of impact frequency, type, and severity on white matter integrity in select brain regions in contact athletes. Current findings expand our knowledge of anatomical changes over the course of a single season, and underscore the importance of considering methodology when interpreting findings in this population, as differing image analysis techniques may lead to different conclusions regarding significant effects.
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    O12.3.Effects of Fingolimod, A Potent Anti-Inflammatory Agent, On Brain Structure, Function, And Symptoms in Schizophrenia
    (Oxford University Press, 2019-04) Breier, Alan; Hummer, Tom; Vohs, Jennifer; Mehdyoun, Nicole; Liffick, Emily; Francis, Michael; Medicine, School of Medicine
    Background New medications with novel targets are needed for schizophrenia. Several lines of evidence indicate that inflammatory processes including aberrant lymphocytic activity may be related to the pathophysiology of this illness. These data suggest that agents with anti-inflammatory actions, including modulation of lymphocytes and their inflammatory substrates, may prove to be efficacious for schizophrenia. Fingolimod is a powerful anti-inflammatory agent that is used in the treatment of relapsing multiple sclerosis. It is a sphingosine-1-phosphate (S1P) receptor modulator that decreases circulating lymphocytes through sequestration in lymph tissues. In addition, evidence suggest that it stimulates oligodendrocytes and may enhance white matter integrity. The purpose of this study was to assess the effects of fingolimod in schizophrenia. Methods Subjects with schizophrenia (N=40) were recruited through the Indiana University Psychotic Disorders Programs and randomized 1:1 in a double-blind, eight-week clinical trial of fingolimod 0.5 mg/day and placebo. Circulating total lymphocytes were determined and effects were assessed on symptoms (PANSS), cognition (BACS), plasma cytokines, white matter integrity (DTI) and cortical connectivity (resting fMRI). Results Results revealed a significant decrease in lymphocytes in subjects taking fingolimod versus placebo (treatment x time; F = 61.2, p < 0.001). Fingolimod treated subjects had a mean maximal drop in lymphocytes from baseline of 79.2% with all fingolimod treated subjects experiencing decrements greater than 60%. There was a trend toward higher mean skeletal fractional anisotropy (FA) post-treatment in the fingolimod group. Within the fingolmiod group, there were significant or trend-level correlations between FA increase and decrease in lymphocytes in the genu and body of the corpus collosum and the right superior longitudinal fasciculus. There were also significant group-by-visit interactions in connectivity of left prefrontal cortical (PFC) seeds with clusters in the cerebellum, driven by higher PFC-cerebellum connectivity following fingolimod treatment. There were no improvements (treatment x time) in PANSS total (F = 0.66, p= 0.52), any of the PANSS subscales, or BACS composite score (F = 0.54, p = 0.44). Serious side effects were not observed, and a full safety report will be provided. Discussion Fingolimod produced a strong anti-inflammatory response with substantial reductions in circulating lymphocytes in all treated subjects. Brain effects were observed. However, this response was not accompanied by improvements in symptoms or cognition. These data suggest that fingolimod’s target of S1P modulation and robust anti-inflammatory warrant further investigation in schizophrenia.