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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 “core” (Figures 12.165–12.169), representing likely irreversibly damaged tissue, is characterized by: TTP: markedly prolonged/delayed.MTT: markedly prolonged/delayed.CBF: markedly reduced, <30% of normal brain blood flow.CBV: reduced.Flow: volume ratio is matched.Matched perfusion deficits: the reduction in CBF is matched by a reduction in CBV.
Brain Monitoring Using Optical Imaging and Optical Spectroscopy
Published in Richard A. Jonas, Jane W. Newburger, Joseph J. Volpe, John W. Kirklin, Brain Injury and Pediatric Cardiac Surgery, 2019
The application of continuous-wave radiation to the imaging of human heart using light in 1971 and transcerebral spectroscopic quantification was first reported by Jöbsis in 1977.3 In a period of time less than twenty years since this report, the measurement of human brain blood flow and oxygenation by Edwards, Delpy et al.16 the noninvasive detection and classification of breast tissues and tumors based upon scattering and absorbance properties in an optical biopsy system by Chance et al.,17 the imaging of animal bodies and human brain by our laboratory,18,19 and a number of other experiments have suggested that optical imaging and spectroscopy are nearing clinical application. In fact, the commercial availability of several near-infrared cerebral monitors and their use in clinical investigation (e.g., studies of cerebral metabolism during administration of neuroprotective agents such as allopurinol,20 designed to protect the brain from injury during lack of oxygen, or studies of the effect of vasoactive compounds on brain blood volume),21,22 demonstrate that, in at least some cases, these technologies are already being applied. Given the potential of light-based technologies to reduce the invasiveness of medical care, to result in better treatments at reduced cost, and to monitor the effectiveness of medical therapies, the potential for the contribution of optical tomography to health care is believed to be great.
Principles of Positron Emission Tomography
Published in W. R. Wayne Martin, Functional Imaging in Movement Disorders, 2019
The past three decades have seen considerable advances in the methods available for measuring brain blood flow, metabolism, and biochemistry. These advances have culminated in the development of positron emission tomography (PET). To help put the advantages of PET into perspective, the methods that were previously available will be briefly described. The pioneering work of Kety and Schmidt in the 1940s resulted in the development of the nitrous oxide method for measuring hemispheric cerebral blood flow (CBF).1 These CBF measurements, when combined with measurements of brain arterial-venous differences for glucose and oxygen, permitted the determination of cerebral metabolism as well. The Kety-Schmidt technique, however, did not provide measurements on a regional basis. The desire to obtain regional rather than global data led to the development of methods to measure CBF with radioactive tracers and external probe systems incorporating multiple radiation detectors placed over the head. They were used to measure the clearance from different brain regions of freely diffusible radioactive gases, such as xenon-133, that were administered either by injection into the internal carotid artery or by inhalation.2,3 Subsequently, external probe techniques using intracarotid injection of tracers labeled with positron-emitting radionuclides were developed for the measurement not only of CBF, but also of cerebral blood volume and metabolism.4
The consideration of post-exercise impact on SCAT3 scores in athletes immediately following a head injury
Published in Brain Injury, 2023
Stephanie Iring-Sanchez, Jenna Tosto, Michelle Favre, Sinae Kim, Michael Falvo, Jorge M. Serrador
One possible limitation to interpretating SCAT data is the lack of comparable control groups to the concussed group in many studies. Typically, post-injury SCAT scores are compared to either baseline measures for that player or a control group of similar uninjured players. However, these players are normally rested (i.e baseline) and have not recently played the associated sport (14, 17–23). Thus, they may not experience numerous symptoms that are associated with the effect of intense exercise and injury to other areas of the body besides the head. Headaches, fatigue, and balance problems are symptoms that have been reported to increase following exercise (24,25). In healthy adults, symptom severity and total number of symptoms within the Sport Concussion Assessment Tool 3 (SCAT3, Version3) have been shown to significantly increase following intense aerobic exercise (26). Additionally, brain blood flow has been shown to increase during exercise influencing the pre-frontal cortex and improving cognitive performance post exercise (27). Consequently, SCAT components are subject to change with intensity of exercise, complicating the interpretation of the results (26,28).
Clinical efficacy of aerobic exercise combined with computer-based cognitive training in stroke: a multicenter randomized controlled trial
Published in Topics in Stroke Rehabilitation, 2022
Ting-Ting Yeh, Ku-Chou Chang, Ching-Yi Wu, Chao-Jung Chen, I-Ching Chuang
Aerobic exercise has been shown to enhance post-stroke cognitive performance in the Trail-Making test, Serial Addition test, and Stroop test.14,27,28 The findings of our study are partially consistent with the results of prior research in supporting that aerobic exercise not only improves general cognitive function (e.g. MoCA) but also optimizes memory function measured by four subtests of WMS-III. Aerobic exercise may lead to upregulation of neurotrophic and vascular growth factors, such as brain-derived neurotrophic factor.29 We speculated that AE does not involve the practice of specific cognitive tasks and that improving results on these specific cognitive tests might not be easy. Yet, AE improved brain blood flow and oxygen perfusion, which may evoke cortical activation of the frontal lobe and possibly promote improvements in general cognitive function.30
Relationship between blood pressure index and cognition in older adults
Published in Clinical and Experimental Hypertension, 2021
Mehmet Ilkin Naharci, Bilal Katipoglu
Previous cross-sectional and longitudinal studies examining older adults found mixed results on the association between arterial stiffness measures and the risk of mild cognitive impairment and dementia, probably due to increased arterial stiffness and severe atherosclerosis (14–16). Thus, clinicians need the different noninvasive and simple using tool, which may provide additive predictive value on cognitive decline. Blood Pressure Index (BPI) is a novel parameter to indicate right ventricular dysfunction and heart failure (17,18). Moreover, decreased cardiac output could increase the risk of developing of cognitive impairment by reducing brain blood flow, which subsequently cause to cerebral ischemia and white matter injury (19,20). However, despite increasing interest in the association of arterial stiffness with cognition, limited data are available regarding the effect of BPI on mental status in community-dwelling older adults. Therefore, this study aimed to investigate the contributions of the BPI and other measurements to cognitive function in older adults.