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https://www.readbyqxmd.com/read/28727355/-perfusion-imaging-of-acute-ischemic-stroke
#1
Carlo W Cereda, Patrik Michel, Karl-Olof Lovblad, Emmanuel Carrera
Multi-modal imaging in acute ischemic stroke includes structural imaging, perfusion imaging and angiographic assessment of brain arteries. Perfusion imaging discriminates brain tissue that is critically hypo-perfused but salvageable (ischemic penumbra) from irreversibly injured tissue (ischemic core). In acute reperfusion therapies (intravenous or endovascular), patients who have substantial penumbra and a small core (target mismatch pattern) are most likely to have a good clinical outcome. Patient selection based on multi-modal imaging is not proven mandatory for acute treatment in patients admitted within the established time-window...
April 26, 2017: Revue Médicale Suisse
https://www.readbyqxmd.com/read/28727192/current-evidence-for-endovascular-therapy-in-stroke-and-remaining-uncertainties-r1
#2
REVIEW
Ronan Motyer, Hamed Asadi, John Thornton, Patrick Nicholson, Hong Kuan Kok
Class 1 level A evidence now supports endovascular thrombectomy as best practice in the management of large vessel occlusion acute ischemic stroke. However, significant questions pertaining to initial imaging, radiological assessment, patient selection and therapeutic limits remain unanswered. A specific cohort of patients who benefit from endovascular thrombectomy has been established, although current uncertainties regarding selection of those not meeting top-tier evidence criteria may potentially deny certain patients the benefit of intervention...
July 20, 2017: Journal of Internal Medicine
https://www.readbyqxmd.com/read/28725211/critical-evaluation-of-the-lund-concept-for-treatment-of-severe-traumatic-head-injury-25%C3%A2-years-after-its-introduction
#3
REVIEW
Per-Olof Grände
When introduced in 1992, the Lund concept (LC) was the first complete guideline for treatment of severe traumatic brain injury (s-TBI). It was a theoretical approach, based mainly on general physiological principles-i.e., of brain volume control and optimization of brain perfusion and oxygenation of the penumbra zone. The concept gave relatively strict outlines for cerebral perfusion pressure, fluid therapy, ventilation, sedation, nutrition, the use of vasopressors, and osmotherapy. The LC strives for treatment of the pathophysiological mechanisms behind symptoms rather than just treating the symptoms...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28717436/endovascular-management-of-chronic-internal-carotid-occlusion-with-penumbra-system
#4
Masoud Mehrpour
No abstract text is available yet for this article.
January 5, 2017: Iranian Journal of Neurology
https://www.readbyqxmd.com/read/28717354/blood-pressure-and-penumbral-sustenance-in-stroke-from-large-vessel-occlusion
#5
REVIEW
Robert W Regenhardt, Alvin S Das, Christopher J Stapleton, Ronil V Chandra, James D Rabinov, Aman B Patel, Joshua A Hirsch, Thabele M Leslie-Mazwi
The global burden of stroke remains high, and of the various subtypes of stroke, large vessel occlusions (LVOs) account for the largest proportion of stroke-related death and disability. Several randomized controlled trials in 2015 changed the landscape of stroke care worldwide, with endovascular thrombectomy (ET) now the standard of care for all eligible patients. With the proven success of this therapy, there is a renewed focus on penumbral sustenance. In this review, we describe the ischemic penumbra, collateral circulation, autoregulation, and imaging assessment of the penumbra...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28712720/manual-aspiration-thrombectomy-in-patients-with-acute-stroke-related-calcified-cerebral-emboli
#6
Esther Koh, Hyo Sung Kwak, Gyung-Ho Chung
OBJECTIVE: The aim of this study was to evaluate the effectiveness of mechanical aspiration thrombectomy (MAT) in patients with acute ischemic stroke from calcified cerebral emboli. METHODS: Procedural results were reviewed for acute stroke patients with clinically neurological deficits who underwent recanalization from October 2012 through September 2015. Initial imaging studies and cerebral angiography were analyzed. RESULTS: Of the total number of patients with acute stroke, 5 patients were confirmed to have acute ischemic stroke by calcified cerebral emboli...
July 13, 2017: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
https://www.readbyqxmd.com/read/28706350/investigating-the-electronic-portal-imaging-device-for-small-radiation-field-measurements
#7
Arpita Agarwal, Nikhil Rastogi, K J Maria Das, S A Yoganathan, D Udayakumar, Shaleen Kumar
PURPOSE: With the advent of state-of-the-art treatment technologies, the use of small fields has increased, and dosimetry in small fields is highly challenging. In this study, the potential use of Varian electronic portal imaging device (EPID) for small field measurements was explored for 6 and 15 MV photon beams. MATERIALS AND METHODS: The output factors and profiles were measured for a range of jaw-collimated square field sizes starting from 0.8 cm × 0.8 cm to 10 cm × 10 cm using EPID...
April 2017: Journal of Medical Physics
https://www.readbyqxmd.com/read/28702878/recent-trends-in-clot-retrieval-devices-a-review
#8
REVIEW
Aamir Hameed, Haroon Zafar, Darren Mylotte, Faisal Sharif
Stroke is the second leading cause of death worldwide and in Europe. Even with gold standard medical management of acute ischemic stroke, which is intravenous (IV) thrombolysis by administration of recombinant tissue plasminogen activator (rt-PA), the mortality rate remains the same. Intra-arterial (IA) thrombolysis therapy also did not achieve significant results and was not approved by the US Food and Drug Administration (FDA) because of limited sample size. This encouraged scientists and engineers to develop endovascular clot retrieval devices for the mechanical recanalization of the occluded arteries in stroke patients...
July 12, 2017: Cardiology and Therapy
https://www.readbyqxmd.com/read/28702115/staged-arterial-and-venous-embolizations-in-treatment-of-type-iv-intraosseous-dural-arteriovenous-fistula
#9
Aleksandra V Betcher, Andrew W Schnure, Paul H Janda, Rajneesh Agrawal, Amandeep Dhillon
OBJECTIVE: This is a case report of an adult male with complex type IV intraosseous DAVF causing severe venous hypertension and bony destruction, presenting with severe hemotympanum, and a novel way of staged arterial and venous embolizations to treat the emergent symptoms. METHODS: First and second stages were direct selective arterial embolizations using Onyx liquid agent. Goal was to reduce flow into the fistula by embolizing the feeder branch and distal penetration of the nidus with Onyx...
June 2017: Journal of Vascular and Interventional Neurology
https://www.readbyqxmd.com/read/28694468/interactome-and-reciprocal-activation-of-pathways-in-topical-mesenchymal-stem-cells-and-the-recipient-cerebral-cortex-following-traumatic-brain-injury
#10
Ping K Lam, Kevin K W Wang, Anthony W I Lo, Cindy S W Tong, Don W C Ching, Kenneth Wong, Zhihui Yang, Themis Kong, Kin K Y Lo, Richard K W Choy, Paul B S Lai, George K C Wong, Wai S Poon
In this study, GFP-MSCs were topically applied to the surface of cerebral cortex within 1 hour of experimental TBI. No treatment was given to the control group. Three days after topical application, the MSCs homed to the injured parenchyma and improved the neurological function. Topical MSCs triggered earlier astrocytosis and reactive microglia. TBI penumbra and hippocampus had higher cellular proliferation. Apoptosis was suppressed at hippocampus at 1 week and reduced neuronal damaged was found in the penumbral at day 14 apoptosis...
July 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28687423/an-increase-of-sigma-1-receptor-in-the-penumbra-neuron-after-acute-ischemic-stroke
#11
Xiaotian Zhang, Fangfang Wu, Yun Jiao, Tianyu Tang, Li Yang, Chunqiang Lu, Yanhong Zhang, Yuan Zhang, Ying Bai, Jie Chao, Gaojun Teng, Honghong Yao
BACKGROUND: Penumbra salvage from infarction by early reperfusion within the time window is the target of acute ischemic stroke therapies. Although the penumbral imaging is potently usable in clinic trial, additional work needs to be performed to advancing the field with better-defined, evaluated, and validated imaging measures. METHODS: Mice were subjected to permanent stroke by right middle cerebral artery (MCA) occlusion. Multimodel magnetic resonance imaging (MRI) method was assessed to define the penumbra as that brain region in which the perfusion and diffusion-weighted MR images are mismatched (perfusion-weighted imaging [PWI]-diffusion-weighted imaging [DWI] mismatch)...
July 4, 2017: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
https://www.readbyqxmd.com/read/28671243/time-dependent-and-lesion-dependent-hmgb1-selective-localization-in-brains-of-patients-with-cerebrovascular-diseases
#12
Takahiko Umahara, Toshiki Uchihara, Katsuiku Hirokawa, Kentaro Hirao, Soichiro Shimizu, Takao Hashimoto, Hiroo Terasi, Haruo Hanyu
High mobility group box 1 protein (HMGB1) has multiple functions, including the maintenance of nucleosomes and the regulation of gene transcription. HMGB1 is released from activated macrophages, resulting in the induction of inflammatory cytokines. Recently, much research about the role of HMGB1 in cerebrovascular disease (CVD) has been reported. In an animal model, HMGB1 neutralization ameliorates brain infarction, there is an early release of HMGB1 from neurons, and HMGB1 antibody attenuates delayed cerebral vasospasm in experimental subarachnoid hemorrhage...
July 3, 2017: Histology and Histopathology
https://www.readbyqxmd.com/read/28669652/severe-vasospasm-of-the-middle-cerebral-artery-after-mechanical-thrombectomy-due-to-infective-endocarditis-an-autopsy-case
#13
Wataru Nishino, Yosuke Tajima, Toru Inoue, Michihiro Hayasaka, Bi Katsu, Koichi Ebihara, Daisuke Kawauchi, Masaaki Kubota, Sumio Suda
Untreated infective endocarditis (IE) often produces infective emboli in major cerebral arteries. We describe a case of middle cerebral artery occlusion due to IE, which caused severe vasospasm and reocclusion after mechanical thrombectomy (MT). We present the pathologic findings of the occluded middle cerebral artery and investigate the precautions to be taken while performing MT due to IE. A 72-year-old man with atrial fibrillation treated with dabigatran presented with right hemiparesis and aphasia. A diffusion-weighted image showed a high-intensity area in the left temporoparietal junction, and magnetic resonance angiography revealed a left M2 occlusion...
June 29, 2017: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
https://www.readbyqxmd.com/read/28666901/characterization-of-the-effect-of-a-new-commercial-transmission-detector-on-radiation-therapy-beams
#14
Joey P Cheung, Angelica Perez-Andujar, Olivier Morin
PURPOSE: To evaluate the influence of a new commercial transmission detector on radiation therapy beams. METHODS AND MATERIALS: A transmission detector designed for online treatment monitoring was characterized on a TrueBeam STx linear accelerator with 6-MV, 6-flattening filter free, 10-MV, and 10-flattening filter free beams. Measurements of percentage depth doses, in-plane and cross-plane off-axis profiles at different depths, transmission factors, and skin dose were acquired with 3 × 3, 5 × 5, 10 × 10, 20 × 20, and 40 × 40 cm(2) field sizes at 100 cm and 80 cm source-to-surface distance (SSD)...
April 9, 2017: Practical Radiation Oncology
https://www.readbyqxmd.com/read/28648945/phosphodiesterase-5-inhibition-as-a-therapeutic-target-for-ischemic-stroke-a-systematic-review-of-preclinical-studies
#15
Joakim N E Ölmestig, Ida R Marlet, Atticus H Hainsworth, Christina Kruuse
Phosphodiesterase 5 inhibitors (PDE5i), such as sildenafil (Viagra®) are widely used for erectile dysfunction and pulmonary hypertension. Preclinical studies suggest that PDE5i may improve functional outcome following ischemic stroke. In this systematic review we aimed to evaluate the effects of selective PDE5i in animal models of brain ischaemia. A systematic search in Medline, Embase, and The Cochrane Library was performed including studies in English assessing the effects of selective PDE5i. 32 publications were included describing outcome in 3646 animals...
June 22, 2017: Cellular Signalling
https://www.readbyqxmd.com/read/28646445/update-on-neurocritical-care-of-stroke
#16
Jason Siegel, Michael A Pizzi, J Brent Peel, David Alejos, Nnenne Mbabuike, Benjamin L Brown, David Hodge, W David Freeman
PURPOSE OF REVIEW: This review will highlight the recent advancements in acute ischemic stroke diagnosis and treatment, with special attention to new features and recommendations of stroke care in the neurocritical care unit. RECENT FINDINGS: New studies suggest that pre-hospital treatment of stroke with mobile stroke units and telestroke technology may lead to earlier stroke therapy with intravenous tissue plasminogen activator (tPA), and recent studies show tPA can be given in previously contraindicated situations...
August 2017: Current Cardiology Reports
https://www.readbyqxmd.com/read/28642575/reactive-astrocytes-function-as-phagocytes-after-brain-ischemia-via-abca1-mediated-pathway
#17
Yosuke M Morizawa, Yuri Hirayama, Noubuhiko Ohno, Shinsuke Shibata, Eiji Shigetomi, Yang Sui, Junichi Nabekura, Koichi Sato, Fumikazu Okajima, Hirohide Takebayashi, Hideyuki Okano, Schuichi Koizumi
Astrocytes become reactive following various brain insults; however, the functions of reactive astrocytes are poorly understood. Here, we show that reactive astrocytes function as phagocytes after transient ischemic injury and appear in a limited spatiotemporal pattern. Following transient brain ischemia, phagocytic astrocytes are observed within the ischemic penumbra region during the later stage of ischemia. However, phagocytic microglia are mainly observed within the ischemic core region during the earlier stage of ischemia...
June 22, 2017: Nature Communications
https://www.readbyqxmd.com/read/28639721/trpv4-channels-contribute-to-calcium-transients-in-astrocytes-and-neurons-during-peri-infarct-depolarizations-in-a-stroke-model
#18
Cordula Rakers, Matthias Schmid, Gabor C Petzold
Stroke is one of the leading causes of death and long-term disability. In the penumbra, that is, the area surrounding the infarct core, peri-infarct depolarizations (PIDs) are accompanied by strong intracellular calcium elevations in astrocytes and neurons, thereby negatively affecting infarct size and clinical outcome. The dynamics of PIDs and the cellular pathways that are involved during PID formation and progression remain incompletely understood. We have previously shown that inositol triphosphate-gated calcium release from internal stores is a major component of PID-related astroglial calcium signals, but whether external calcium influx through membrane-localized channels also contributes to PIDs has remained unclear...
June 22, 2017: Glia
https://www.readbyqxmd.com/read/28639376/mfat-1-transgene-protects-cultured-adult-neural-stem-cells-against-cobalt-chloride-mediated-hypoxic-injury-by-activating-nrf2-are-pathways
#19
Junfeng Yu, Haiyuan Yang, Bin Fang, Zhengwei Zhang, Ying Wang, Yifan Dai
Ischemic stroke is a devastating neurological disorder and one of the leading causes of death and serious disability in adults. Adult neural stem cell (NSC) replacement therapy is a promising treatment for both structural and functional neurological recovery. However, for the treatment to work, adult NSCs must be protected against hypoxic-ischemic damage in the ischemic penumbra. In the present study, we aimed to investigate the neuroprotective effects of the mfat-1 transgene on cobalt chloride (CoCl2 )-induced hypoxic-ischemic injury in cultured adult NSCs as well as its underlying mechanisms...
June 22, 2017: Journal of Neuroscience Research
https://www.readbyqxmd.com/read/28639301/improving-the-detection-sensitivity-of-ph-weighted-amide-proton-transfer-mri-in-acute-stroke-patients-using-extrapolated-semisolid-magnetization-transfer-reference-signals
#20
Hye-Young Heo, Yi Zhang, Tina M Burton, Shanshan Jiang, Yansong Zhao, Peter C M van Zijl, Richard Leigh, Jinyuan Zhou
PURPOSE: To quantify amide protein transfer (APT) effects in acidic ischemic lesions and assess the spatial-temporal relationship among diffusion, perfusion, and pH deficits in acute stroke patients. METHODS: Thirty acute stroke patients were scanned at 3 T. Quantitative APT (APT(#) ) effects in acidic ischemic lesions were measured using an extrapolated semisolid magnetization transfer reference signal technique and compared with commonly used MTRasym (3.5ppm) or APT-weighted parameters...
June 21, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
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