Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Ischemic stroke is mainly caused by embolism. Vascular emboli can be solid or gaseous and can be non-invasively registered by transcranial Doppler ultrasound as microembolic signals (MESs). The existing methods are limited as they do not distinguish between cases in which a single embolus is present and those in which multiple emboli -- perhaps a mix of those gaseous and solid in nature -- are present. In a previous in vitro study, we have developed a wavelet-based algorithm to detect multiple emboli. We proceed with this technique to investigate whether it could prove useful in patients. ⋯ Multiple emboli were detected and quantified in patients using continuous wavelet transform. These were difficult to observe using conventional analysis techniques.
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The determinants of ischemic complications in subarachnoid hemorrhage (SAH) are not well defined. The objective of this study is to evaluate the role of microemboli in SAH-related cerebral ischemia. ⋯ In this study, ES detected in over a third of SAH victims, were associated with the development of cerebral ischemic symptoms, and were not related to vasospasm, but rather appeared to be an independent risk factor for the development of ischemic symptoms in SAH.
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In hyperarginenemia, there is a defect in argininase enzyme, which is a catalyzer of urea cycle. Though the pathogenesis of neuronal damage in hyperargininemia is not clear, high serum and cerebrospinal fluid arginine levels can be directly related with neuronal damage. In this study, our aim was to assess brain magnetic resonance images and magnetic resonance spectroscopy (MRS) patterns of two siblings with hyperarginenemia. ⋯ We observed mild cerebral and cerebellar atrophy and infarct at bilateral posterior putamen and insular cortex localization on conventional images and elevated choline/creatine ratios and abnormal peak at 3.8 ppm, most likely representing arginine deposition. To the best of our knowledge, this is the first article revealing the brain MRS pattern of hyperargininemia. We reported the clinical and imaging findings of patients and discuss the correlation.
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We studied an auditory continuous performance task with positron emission tomography(PET) and EEG-derived current density reconstructions (CDRs) to define the spatial and temporal aspects of auditory attention. ⋯ The cingulate may play an important role in post-decisional activity and control activity at other sites involved in post-decisional cognitive processing.
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Hypertensive encephalopathy typically presents with headache and confusion and bilateral parietooccipital vasogenic edema. Brain stem and cerebellar edema in hypertensive encephalopathy usually occurs in association with these typical supratentorial changes and is usually asymptomatic. ⋯ Rapid treatment of hypertension resulted in clinical and radiological improvement. Prompt recognition of the cause and aggressive treatment of hypertension in such patients are crucial to relieve edema and prevent life-threatening progression.