Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Quantitative T1 and diffusion tensor imaging (DTI) may provide information about pathological changes underlying disability and progression in diseases like multiple sclerosis (MS). Imaging the corpus callosum (CC), a primary site of damage in MS with a critical role in interhemispheric connectivity, may be useful for assessing overall brain health, prognosis, and therapy efficacy. We assessed the feasibility of multisite clinical trials using advanced MRI by examining the intra and intersite reproducibility of T1 and DTI measurements in the CC and segmented white matter (WM). ⋯ T1 and DTI measures are reproducible using equivalent MRI scanners and sequence protocols. Using a similar MR system, it is feasible to carry out multicenter studies using T1 and DTI to evaluate changes within the CC and WM.
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Dopamine and glutamate reciprocally regulate each other in some of the neurocircuits affected by Parkinson's disease (PD). The objective of this pilot study was to explore relationships between these neurotransmitter systems with positron emission tomography. ⋯ mGluR5 seems upregulated in strategic dopaminergic brain regions adversely affected by PD. The findings seem to confirm that DaT tracers are better discriminatory biomarkers for diagnosing PD; however, mGluR5 tracers might deserve further exploration as potential biomarkers of response in clinical trials.
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Measuring head circumference (HC) in infants is an easy screening procedure with which to detect abnormalities in brain growth. It has been demonstrated that HC can predict total brain volume (TBV) in very-low-birth-weight (VLBW) infants. However, the correlation between HC and TBV was weaker than that observed in healthy term-born toddlers, suggesting that there are factors that influence the relationship between HC and TBV. The aim of this study was to identify the clinical risk factors that caused a deviation from the regression line obtained between HC and TBV. ⋯ Although HC has predictive value for TBV in VLBW infants, care should be taken in infants with low BBW (BBW less than 600 g) or dolichocephaly (MRI-based cranial index less than .68), which were related to overestimation of TBV.
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Pediatric-onset multiple sclerosis (POMS) is a demyelinating disorder with unique clinical challenges. A brief computer-administered cognitive screening battery measuring processing speed (Cogstate) and the Brief International Cognitive Assessment in MS (BICAMS) detect cognitive impairment in POMS. The neuroanatomic correlates of these deficits are incompletely understood. The purpose of this study is to define the neuroanatomic underpinnings of deficits identified with cognitive screening batteries in POMS. ⋯ Computer-administered measures of cognitive processing are particularly sensitive in POMS and are closely linked to white matter FA.
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Teriflunomide reduces disability progression and brain atrophy in multiple sclerosis patients. The exact mechanism of action by which teriflunomide exerts these effects is currently unknown. We assessed the effect of teriflunomide on brain glial cells in the Theiler's murine encephalomyelitis virus (TMEV) by using a histological approach in combination with neuroimaging. ⋯ Teriflunomide altered microglia density and oligodendrocytes differentiation, which was associated with less evident microstructural damage on MRI.