China
Africa
Explore chapters and articles related to this topic
Stroke
Published in Ibrahim Natalwala, Ammar Natalwala, E Glucksman, MCQs in Neurology and Neurosurgery for Medical Students, 2022
Ibrahim Natalwala, Ammar Natalwala, E Glucksman
Concerning strokes and transient ischaemic attacks, which of the following statements are true and which are false? The salvageable area surrounding an infarction is known as the penumbra.Amaurosis fugax is sudden-onset transient monocular blindness due to retinal artery occlusion.The lenticulostriate arteries arise from the anterior cerebral artery.A stroke involving the middle cerebral artery is likely to produce aphasia.During the acute management of a stroke, achieving a normal blood pressure is of importance.
Nonclassical Ion Channels and Ischemia
Published in Tian-Le Xu, Long-Jun Wu, Nonclassical Ion Channels in the Nervous System, 2021
Stroke is the second leading cause of death in the world, with high mortality in China, which has nearly 20% of the world’s population [1]. Stroke can be classified to mainly two types: hemorrhagic stroke and ischemic stroke, and the latter constitutes about two-thirds of all stroke patients [2]. Ischemic stroke is caused by thrombosis, which reduces blood flow and interrupts blood supply, inducing localized damage in brain-specific tissues under hypoxia, leading to a complex syndrome in the brain. Ischemic stroke survivors suffer different dysfunction in sensory function, motor skills, cognition, and learning and memory. Currently in clinical practice, stroke patients can receive recombination tissue plasminogen activator (tPA) for injection within a therapeutic window of 4.5 hours. This has promising effectiveness but is only suitable for 3%–4% of patients and still has a risk of hemorrhage [3]. With acute ischemia, the ischemic core suffers an irreversible injury and subsequent cell death in minutes, and the ischemic penumbra progressively converts to ischemic core over several hours or days. Understanding the differences between penumbra and core, many treatments have tried to focus on the preservation of the penumbral brain, which can be salvaged and recover its normal function [4]. Besides, along with the development of new therapeutic intervention, more and more researches explore the complex molecular mechanism of ischemia to find potential strategies for treatment.
Stroke and Transient Ischemic Attacks of the Brain and Eye
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
The ischemic penumbra is the area of potentially reversible and salvageable ischemic brain tissue, where there is moderately reduced cerebral perfusion that is not sufficient to have produced infarction, compensatory vasodilation to maintain flow, increased oxygen extraction, and reduced cerebral metabolism. The ischemic penumbra usually surrounds the infarct core. It is characterized on CT perfusion as an area of moderately reduced CBF, prolonged MTT, or Tmax and normal or even increased CBV due to autoregulatory vasodilation (see Vascular Imaging above).
Can dosimetry affect local control and survival in patients with early-stage lung cancer treated with Stereotactic Ablative Radiotherapy (SABR)? An analysis of the UK's largest cohort of lung SABR patients
Published in Acta Oncologica, 2021
Animesh Saha, Matthew Beasley, Nathaniel Hatton, Peter Dickinson, Kevin Franks, Katy Clarke, Pooja Jain, Mark Teo, Patrick Murray, John Lilley
Surgical series have reported microscopic disease extension in the region of 8–26 mm in NSCLC patients [37–40]. It is assumed that high dose penumbra is sufficient to treat microscopic disease extension when treating with SABR techniques [33]. It is possible that as SABR treatment plans become increasingly conformal, with steeper dose gradients, tumour control will be compromised. There are few studies, which assess the effects of lung SABR dosimetry on clinical outcome [11]. Diamant et al. explored the correlation between radiation dose close to PTV with loco-regional recurrence and distant metastases in 217 patients. They showed a tight conformality of radiotherapy plans with a mean dose of ≤20.8 Gy delivered to a 3 cm rind around the PTV resulted in a higher rate of distant metastases (2-year distant metastases rate 60% vs. 5%). They suggested caution for radiotherapy plans with steep dose gradients and raised the question about the need for secondary margins in the region of 2 cm around PTV with a lower prescription dose (around 21 Gy) to take into account microscopic disease extension and to reduce the risk of distant metastases [11].
Introduction to laser thermal therapy for brain disorders
Published in International Journal of Hyperthermia, 2020
Jennifer S. Yu, Alireza M. Mohammadi
Moreover, in this era of immunotherapy, hyperthermia may be regarded as a tool for creating personalized, in situ cancer vaccines (readers are referred to the special issue on Thermal Therapy and Immunotherapy: at the Crossroads of New Discovery [2]). Hyperthermia has numerous effects on cancer cells and their surrounding microenvironment. Direct tumoricidal effects of ablative hyperthermia and thermal effects within lower temperature zones sensitize cancer cells, including cancer stem cells, to radiation and chemotherapy [3,4]. Consequently, tumor antigen spillage can provoke an anti-tumor immune response. The lower temperature penumbra has numerous effects including increasing blood perfusion, improving tissue oxygenation to render radiation more effective, improving chemotherapy penetration into the tumor, and augmenting immune cell recruitment [5]. Emerging data also support the role of hyperthermia in disrupting the blood-brain-barrier and/or blood-tumor-barrier [6]. These insights inform how hyperthermia can be integrated with other treatment modalities including immunotherapy to take full advantage of the biologic consequences of hyperthermia.
Methodological considerations for kinematic analysis of upper limbs in healthy and poststroke adults. Part I: A systematic review of sampling and motor tasks
Published in Topics in Stroke Rehabilitation, 2019
Inês Albuquerque Mesquita, Ana Rita Vieira Pinheiro, Miguel Fernando Paiva Velhote Correia, Cláudia Isabel Costa da Silva
Surprisingly, only two articles23,25 indicated the stroke location, whereas the stroke type was reported by several articles.9,10,21,23,25 The lesion location is generally assumed to be associated with the specificity of deficits.39 Furthermore, recent data suggest that the site of ischemic penumbra could predict outcome or treatment response and affect motor recovery.40 Therefore, future studies should analyze kinematically the impact of stroke location on UL motor function. To report stroke location and make easier comparisons between studies, the SRRR recommended the following categorization: cortical (internal capsule/middle cerebral artery/frontal lobe), subcortical (thalamus/basal ganglia), midbrain (pons/medulla/cerebellum), and brainstem.3