Valdezmacdonald1097

Clinical evidence of mechanical thrombectomy for acute ischemic stroke(AIS)has been reported since 2015, and there is an urgent need for the preparation of medical treatment systems for AIS. The Japan Stroke Society and the Japan Circulation Society published a 5-year plan for stopping CVD in December 2016. In December 2018, the Stroke and Cardiovascular Disease Control Act was enacted in Japan. In this review, we present the future plan of medical treatment systems for stroke.Proton magnetic resonance spectroscopy(1H-MRS)is a non-invasive method for evaluating brain function and metabolism. 1H-MRS can quantify low-molecular-weight metabolites in a living brain; it shows their spectra without tracer administration. In this paper, we introduce 1H-MRS and MRS for imaging the distribution of metabolites. The applications of 1H-MRS imaging for several neurological disorders will be outlined.The risk of future ischemic events, such as angiographically determined stenosis and ulceration, in patients with atherosclerosis has long been mainly assessed using luminal morphology. However, recent remarkable advances in vessel wall imaging combined with a deeper understanding of vascular biology have shown that vessel wall characteristics also have a considerable influence on the onset of ischemic events. Among the modalities for vessel wall imaging, such as ultrasound, CT, and MRI, MRI is useful for plaque characterization because of its high accuracy and less invasiveness. Several features of vulnerable plaques, such as intraplaque hemorrhage, large lipid-rich necrotic cores, and ruptured fibrous caps, can be observed using contemporary high-resolution MRI. The assessment of plaque characteristics is essential for the management of atherosclerosis. In this article, the current status of carotid plaque characterization using black-blood MRI will be briefly highlighted, and potential clinical implications of MRI plaque imaging will be demonstrated.Computational fluid dynamics(CFD)is a useful tool for simulating blood flow and has been applied to hemodynamic analysis in cerebrovascular disease. Although CFD requires an engineering approach, it can potentially contribute to preoperative surgical simulation as an intraoperative aid. In this study, we describe the basic hemodynamic parameters for CFD analysis and demonstrate their effective practical use by focusing on intracranial aneurysms. A thinning cerebral aneurysmal wall indicates a rupture risk, and it cautions neurosurgeons of an intraoperative rupture. High pressure and low wall shear stress(WSS)have been proposed as hemodynamic parameters that are related to a thinning wall. However, an atherosclerotic region is occasionally observed, and a combination of low WSS and high oscillatory shear index characterizes these wall lesions. One representative case of ruptured middle cerebral artery aneurysm showed that high pressure and low WSS can lead to the identification of rupture points in pre-rupture analysis. Meanwhile, in endovascular surgery, we conducted flow analysis in the residual cavity after coil embolization via metal artifact reduction using silent MR angiography. With the development of imaging modalities, a combination with CFD analysis can lead to new findings. Thus, use of CFD software by neurosurgeons for clinical applications is important.Neuronal intranuclear inclusion disease(NIID)is a progressive neurodegenerative condition characterized by eosinophilic hyaline intranuclear inclusions in neuronal and other somatic cells. Since 2011, when skin biopsy was proven to be a diagnostic tool, the incidence of NIID has been increasing. Its symptoms include dementia, muscle weakness, and sensory or autonomic disturbance. MRI shows hyperintense lesions of the subcortical white matter, especially on the U-fiber. These findings persist and continue to worsen for years.Mild encephalitis/encephalopathy with a reversible splenial lesion(MERS)is a clinically and radiologically benign condition that has been described within the past two decades. MRI findings include isolated symmetrical ovoid lesions of the splenium with a high-intensity signal on DWI and decreased apparent diffusion coefficient. These findings have been associated with viral infections, epilepsy, antiepileptic drug usage, and metabolic disturbances, among others. These conditions may present with severe clinical features, such as consciousness disturbance or cytokine storm; however, patients usually recover completely with optimal treatment. Some pathological conditions with splenic lesions, such as Marchiafava-Bignami disease, may be irreversible. Therefore, diseases with splenic lesions require careful attention.Sporadic Creutzfeldt-Jacob disease(sCJD)is a prion disease presenting with subacute or rapidly progressive dementia with a poor prognosis. Asymmetrical cortical lesions with thalamic involvement are found in sCJD cases, which is similar distribution to status epileptics, but the lesions are not observed in the limbic systems, and they rarely occur in the precentral gyrus. Characteristically, hyperintense abnormal findings are more prominent on DWI than on FLAIR and T2WI. 19.9% of CJD is genetic CJD(gCJD), and CJD with a mutation of codon 180 from valine to isoleucine(V180I)accounts for 40% of gCJD in Japan. Patients with this type of gCJD rarely have a family history because of the low penetration rate. The age of onset is usually later, and its clinical symptoms deteriorate more slowly than sCJD. DWI shows abnormal cortical hyperintense signals(cortical ribboning).Less than half of the cases of autoimmune encephalitis have brain MRI abnormalities; however, some patterns of MRI findings help diagnosis. Usually, DWI and FLAIR images reveal hyperintensity lesions in the cortical or subcortical regions or the cerebellum and/or the brainstem. Hyperintensity lesions in the limbic cortex on DWI suggest NMDAR encephalitis. RA or polychondritis-related meningitis show bright dot or linear signals on the convexities on DWI. Area postrema syndrome is a typical form of neuromyelitis optica. These conditions need to be diagnosed promptly for effective treatment.Dysplastic cerebellar gangliocytoma or Lhermitte-Duclos disease(LDD)is a rare benign cerebellar lesion composed of dysplastic ganglion cells that conform to the existing cortical architecture. In this disease, the enlarged ganglion cells are predominantly located within the internal granular layer, and they thicken the cerebellar folia. The architecture of the affected cerebellar hemisphere with the enlarged cerebellar folia and the cystic changes, in some cases, present as "tiger-striped striations," a characteristic imaging finding that is not specific to LDD. This imaging feature may be observed in medulloblastoma and isolated cerebellar Rosai-Dorfman disease. This cerebellar lesion is a major central nervous system manifestation of Cowden syndrome, an autosomal dominant condition that causes various hamartomas and neoplasms. A molecular-based study estimated the prevalence of Cowden syndrome to be 1 case per 200,000. In a study involving 211 patients with Cowden syndrome, 32% developed LDD. LDD can be diagnosed in young children and older adults within the eighth decades of life. PTEN mutations have been identified in virtually all adult-onset LDDs, but not in childhood-onset cases.Primary melanocytic neoplasms of the central nervous system(CNS)presumably arise from leptomeningeal melanocytes that are derived from the neural crest. Melanocytic neoplasms associated with neurocutaneous melanosis likely derive from melanocyte precursor cells that reach the CNS after somatic mutations, mostly, of the NRAS. XST-14 manufacturer They should be distinguished from other melanotic tumors involving the CNS, including metastatic melanoma and other primary tumors that undergo melanization, such as melanocytic schwannomas, medulloblastomas, paragangliomas, and various gliomas, because these lesions require different patient workups and therapy. Primary melanocytic neoplasms of the CNS that are diffuse and do not form macroscopic masses are called melanocytoses, whereas malignant diffuse or multifocal lesions are collectively called melanomatoses. Benign and intermediate-grade tumoral lesions are called melanocytomas. Discrete malignant tumors are called melanomas. CT and MRI of melanocytosis and melanomatosis show diffuse thickening and enhancement of the leptomeninges, often with focal or multifocal nodularity. Depending on the melanin content, diffuse and circumscribed melanocytic tumors of the CNS may show some characteristics on CT and MRI iso- to hyperattenuation on CT and paramagnetic properties of melanin on MRI resulting in an isointense signal on T1WIs and iso- to hypointensity on T2WIs.Multinodular and vacuolating neuronal tumors of the cerebrum(MVNTs)are rare brain tumors that were described first in 2013. MVNTs have been added to the World Health Organization Classification of Tumors of the Central Nervous System in 2016(2016WHO), although an MVNT is a clinical-pathological lesion with uncertain class assignment. It remains unclear whether MVNTs should be considered a true neoplasm or malformative lesion. Their prevalence and pathophysiology are unknown. MVNTs typically occur in adults, predominantly in the cerebral subcortical region, and are most frequently associated with seizures or seizure equivalents. MVMTs can also present incidentally without seizures. MVNTs have been reported to show highly suggestive imaging features, especially on MRI scans. MVNTs consist of small T2 and T2-FLAIR hyperintense nodules in subcortical and juxtacortical areas with rare or no post-contrast enhancement. Most MVNTs reported in the literature involve the supratentorial part of the brain. Recently, lesions exhibiting a remarkably similar pattern of imaging findings were described in the posterior fossa, which are referred to as multinodular and vacuolating posterior fossa of unknown significance(MV-PLUS). Both MVNT and MV-PLUS are considered "leave-me-alone" lesions because of the absence of malignancy criteria and the lack of evolutivity on follow-up MRI scans.Tumefactive demyelinating lesion(TDL)is defined as a large lesion, size >2 cm, mass effect, perilesional edema and/or ring enhancement. TDL could occur in multiple sclerosis(MS), neuromyelitis optica spectrum disorder(NMOSD), acute disseminated encephalomyelitis(ADEM)or other immunological diseases. Non-invasive methods including MR imaging and assay of several autoantibodies(e.g. aquaporin-4 autoantibodies)are recommended when each TDL is identified. The radiological findings on MRI are characterized by size >2 cm, mass effect, perilesional edema, T2 weighted hypointense rim, peripheral diffusion restriction, open ring enhancement, vascular enhancement, and central vein sign. When atypical clinical and radiological presentations are present in patients with TDL, diagnosis may necessitate brain biopsy due to exclude alternative pathology(e.g. primary central nervous system lymphoma). Because treatments and outcomes for patients with TDL are dependent on each disease etiology including MS, NMOSD, ADEM or others, we should always clarify the entire picture behind the disease.