Journal of neuroimaging : official journal of the American Society of Neuroimaging
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A 41-year-old male presented with an acute onset of headache, confusion, seizures, and unilateral focal neurological deficit 25 years after receiving whole-brain radiation therapy to treat a cerebellar medulloblastoma. Brain magnetic resonance imaging (MRI) demonstrated a thick unilateral parieto-occipital cortical contrast enhancement. ⋯ Here, we describe the brain MR spectroscopy findings of SMART, showing a decrease in N-acetyl-aspartate and increased levels of creatine and choline, corresponding with neuronal destruction or transient neuronal impairment with mild nonspecific gliosis. The absence of a lactate peak suggests that mitochondrial dysfunction, vasospasm or ischemic mechanisms were not involved.
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Brainstem intracranial dural arteriovenous fistulas are extremely rare and can mimic a glioma at the time of presentation. ⋯ A careful radiological study looking for dilated vessels around the brainstem is necessary in the workup of an infiltrating brainstem lesion, in order to rule out intracranial dural arteriovenous fistula.
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The phenomenon known as neural flow coupling (NFC) occurs at the capillary level where there are no known pressure controlling structures. Recent developments in advanced magnetic resonance imaging technologies have made possible in vivo direct investigations of water physiology that have shed new insight on the water dynamics of the cortical pericapillary space and their complex functionality in relation to NFC. Neural activities initiate a chain of events that ultimately affect NFC. ⋯ Reduction of pericapillary water pressure results in a negative balance between pericapillary and intraluminal capillary pressure, allowing for capillary caliber expansion. Proton permeability through the tight junctions of the blood brain barrier is significantly high owing to the Grotthuss proton "tunneling" mechanism and, therefore, carbonic anhydrase (CA) type IV (CA-IV) anchored to the luminal surface of brain capillaries functions as scavenger of extracellular protons. CA-IV inhibition by acetazolamide or carbon dioxide results in the accumulation of extracellular protons, causing AQP-4 inhibition and a secondary increase in rCBF.
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Ultrasonographic measurement of optic nerve sheath diameter (ONSD) can successfully be used to estimate intracranial pressure (ICP) elevation. Its utility in corroboration of brain death (BD) was herein studied. ⋯ ONSD is significantly greater in subjects with BD. However, quantification of ONSD cannot discriminate BD subjects from comatose ones with raised ICP with 100% certainty.
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Prognostic evaluation based on cortical vein score difference in stroke (PRECISE) score, a novel venous grading scale better predicted stroke outcomes. Henceforth, we aimed to describe and determine if a physiologically relevant combined arterial and venous grading scale (CRISP grading scale) is accurate in determining 90-day stroke outcomes in patients with proximal arterial occlusion in the anterior circulation. ⋯ CRISP grading was precise in predicting stroke outcomes when compared to individual imaging scales including arterial collateral grading, PRECISE score and CTA-SI ASPECTS in patients with proximal arterial occlusion in the anterior circulation.