Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Cerebrovascular reactivity (CR) is an ideal biomarker to detect cerebrovascular damage. CR can be quantified by measuring changes in cerebral blood flow velocity (CBFV) resulting from a CO2 vasodilatory stimulus, often using the breath-holding index (BHI). In this method, transcranial Doppler (TCD) ultrasound is used to measure CBFV changes in the middle cerebral artery (MCA) during a breath-hold maneuver. Despite its convenience, BHI has high variability. Changing body position may contribute to potential variability. It is important to determine if CR differs with body position. The aims of this study were, first, to propose an alternative, more robust index to evaluate CR using a breath-hold maneuver; second, investigate the effect of body position on CR measured with conventional (BHI) and a new proposed index. ⋯ BHAI has less variability in comparison with the conventional standard BHI. Additionally, neither index showed statistical significance in CR based on change in body position.
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Evidence is needed to understand the effect of fingolimod on slowing down brain atrophy progression in multiple sclerosis (MS) patients in clinical practice. We investigated the effect of fingolimod on brain atrophy in MS patients with active disease (clinically and/or magnetic resonance imaging [MRI]) versus no evidence of active disease (NEAD). ⋯ The study provides real-world evidence that rate of brain atrophy in MS patients with underlying active disease and NEAD in fingolimod treated patients is below the established pathological cutoff for loss of whole brain volume (>-.4%) or expansion of lateral ventricles (> 3.5%).
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Tai Chi is a mind-body exercise that has been shown to improve both mental and physical health. As a result, recent literature suggests the use of Tai Chi to treat both physical and psychological disorders. However, the underlying physiological changes have not been characterized. The aim of this pilot study is to assess the changes in brain metabolites and muscle energetics after Tai Chi training in an aging population using a combined brain-muscle magnetic resonance spectroscopy (MRS) examination. ⋯ Our pilot study demonstrates significant increase of NAA/Cr ratios in posterior cingulate gyrus and significantly improved PCr recovery time in leg muscles in older adults following short-term Tai Chi training, and thus provides insight into the beneficial mechanisms.
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The thalamus is a part of the diencephalon, containing numerous connections between the forebrain and subcortical structures. It serves an important function as a relay center between the cerebral cortex and the subcortical regions, particularly with sensory information. The thalamus also plays a major role in regulating arousal and the levels of awareness. ⋯ In addition, we will also review the variant thalamic territories and associated infarction syndromes of the anteromedian, central, and posterolateral territories. This review article is aimed to better the clinical and radiologic understanding as well as the diagnosis of classic and variant thalamic territory infarcts. This article will also briefly touch on the recovery of function after thalamic infarcts.
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Cerebral microinfarcts (CMI) are associated with intracerebral hemorrhage due to small vessel disease (SVD) in studies not including an ischemic etiologic workup. We aimed to determine their incidence and potential causes in a large ischemic stroke (IS) cohort. ⋯ CMIs occurring within the vascular territory of a larger infarct are more likely embolic, but those occurring outside are probably related to SVD. Our findings suggest a role for SVD in pathogenesis of CMIs and emphasize the importance of etiologic workup to identify alternate etiologies.