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Search Results: 1 - 10 of 5522 matches for " cerebrovascular reserve capacity "
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Neurosonological examination: A non-invasive approach for the detection of cerebrovascular impairment in AD
Barbora Urbanova,Ales Tomek,Robert Mikulik,Hana Magerova,Daniel Horinek,Jakub Hort
Frontiers in Behavioral Neuroscience , 2014, DOI: 10.3389/fnbeh.2014.00004
Abstract: There has been a growing interest in vascular impairment associated with Alzheimer’s disease (AD). This interest was stimulated by the findings of higher incidence of vascular risk factors in AD. Signs of vascular impairment were investigated notably in the field of imaging methods. Our aim was to explore ultrasonographic studies of extra- and intracranial vessels in patients with AD and mild cognitive impairment (MCI) and define implications for diagnosis, treatment and prevention of the disease. The most frequently studied parameters with extracranial ultrasound are intima-media thickness in common carotid artery, carotid atherosclerosis, and total cerebral blood flow. The transcranial ultrasound concentrates mostly on flow velocities, pulsatility indices, cerebrovascular reserve capacity, cerebral microembolization. Studies suggest there is morphological and functional impairment of cerebral circulation in AD compared to healthy subjects. Ultrasound as a non-invasive method could be potentially useful in identifying individuals in a higher risk of progression of cognitive decline.
Comparison of Perfusion Weighted Magnetic Resonance Imaging and Single Photon Emission Computed Tomography for Assessment of Cerebrovascular Reserve in Symptomatic Carotid Territory Stenosis  [PDF]
Stephen T. McSorley, Krishna A. Dani, Jim Patterson, David Brennan, Donald M. Hadley, Keith Muir
Open Journal of Radiology (OJRad) , 2012, DOI: 10.4236/ojrad.2012.23013
Abstract: Background: Perfusion Weighted Magnetic Resonance Imaging (PW-MRI) and HMPAO Single Photon Emission Computed Tomography (SPECT) are both cerebral perfusion measurement techniques. Imaging before and after acetazolamide administration can assess cerebrovascular reserve in symptomatic haemodynamic cerebrovascular disease. We compared SPECT and PW-MRI parameters in this patient group. Methods: We identified 10 patients with haemody-namically induced symptoms and intra- or extra-cranial arterial stenoses with back-to-back acetazolamide challenge SPECT and PW-MRI, 4 of whom had resting studies. Regions of interest (ROIs) were applied to parameter maps using an ASPECTS template and perfusion parameters expressed relative to contralateral ROIs, giving 118 challenge and 48 resting ROIs. Results: SPECT relative cerebral blood flow (rCBF) correlated with PW-MRI time to peak (TTP) (r = ?0.568), mean transit time (MTT) (r = ?0.317), regional cerebral blood flow (rCBF) (r = 0.299) and cerebral blood volume (CBV) (r = 0.224). Bias between SPECT and PW-MRI rCBF was small (?0.018) with wide limits of agreement and a systematic measurement error. Pre- to post-acetazolamide PW-MRI rCBF change showed poor sensitivity and specificity for detecting change in SPECT rCBF. SPECT and PW-MRI rCBF had stronger correlation and smaller bias in unilateral stenosis than with bilateral stenosis. Conclusion: Systematic bias between techniques limits interchange- ability in cerebrovascular reserve measurement in patients with cerebrovascular stenosis.
Contribution of Physical Fitness, Cerebrovascular Reserve and Cognitive Stimulation to Cognitive Function in Post-Menopausal Women
Gail A. Eskes,Stewart Longman,Allison D. Brown,Carly A. McMorris,Kristopher D. Langdon,David B. Hogan,Marc Poulin
Frontiers in Aging Neuroscience , 2010, DOI: 10.3389/fnagi.2010.00137
Abstract: Studies of the effects of physical fitness on cognition suggest that exercise can improve cognitive abilities in healthy older adults, as well as delay the onset of age-related cognitive decline. The mechanisms for the positive benefit of exercise and how these effects interact with other variables known to influence cognitive function (e.g., involvement in cognitive activities) are less well understood. The current study examined the associations between the physical fitness, cerebrovascular blood flow regulation and involvement in cognitive activities with neuropsychological function in healthy post-menopausal women. Methods: Forty-two healthy women between the ages of 55 and 90 were recruited. Physical fitness ( max), cerebrovascular reserve (cerebral blood flow during rest and response to an increase in end-tidal (i.e., arterial) PCO2), and cognitive activity (self-reported number and hours of involvement in cognitive activities) were assessed. The association of these variables with neuropsychological performance was examined through linear regression. Results: Physical fitness, cerebrovascular reserve and total number of cognitive activities (but not total hours) were independent predictors of cognitive function, particularly measures of overall cognitive performance, attention and executive function. In addition, prediction of neuropsychological performance was better with multiple variables than each alone. Conclusions: Cognitive function in older adults is associated with multiple factors, including physical fitness, cerebrovascular health and cognitive stimulation. Interestingly, cognitive stimulation effects appear related more to the diversity of activities, rather than the duration of activity. Further examination of these relationships is ongoing in a prospective cohort study.
Insulin resistance and exercise tolerance in heart failure patients: linkage to coronary flow reserve and peripheral vascular function
Martin Snoer, Tea Monk-Hansen, Rasmus Olsen, Lene Pedersen, Lene Simonsen, Hanne Rasmusen, Flemming Dela, Eva Prescott
Cardiovascular Diabetology , 2012, DOI: 10.1186/1475-2840-11-97
Abstract: 39 patients with LVEF?<?35% (median LV ejection fraction (LVEF) 31 (interquartile range (IQ) 26–34), 23/39 of ischemic origin) underwent echocardiography with measurement of CFR. Peak coronary flow velocity (CFV) was measured in the LAD and coronary flow reserve was calculated as the ratio between CFV at rest and during a 2?minutes adenosine infusion. All patients performed a maximal symptom limited exercise test with measurement of peak oxygen uptake (VO2peak), digital measurement of endothelial function and arterial stiffness (augmentation index), dual X-ray absorptiometry scan (DEXA) for body composition and insulin sensitivity by a 2?hr hyperinsulinemic (40?mU/min/m2) isoglycemic clamp.Fat free mass adjusted insulin sensitivity was significantly correlated to VO2peak (r?=?0.43, p?=?0.007). Median CFR was 1.77 (IQ 1.26-2.42) and was correlated to insulin sensitivity (r 0.43, p?=?0.008). CFR (r?=?0.48, p?=?0.002), and arterial stiffness (r?=??0.35, p?=?0.04) were correlated to VO2peak whereas endothelial function and LVEF were not (all p?>?0.15). In multivariable linear regression adjusting for age, CFR remained independently associated with VO2peak (standardized coefficient (SC) 1.98, p?=?0.05) whereas insulin sensitivity (SC 1.75, p?=?0.09) and arterial stiffness (SC ?1.17, p?=?0.29) were no longer associated with VO2peak.The study confirms that insulin resistance is associated with exercise intolerance in heart failure patients and suggests that this is partly through reduced CFR. This is the first study to our knowledge that shows an association between CFR and exercise capacity in heart failure patients and links the relationship between insulin resistance and exercise capacity to CFR.The link between insulin resistance and heart failure is complex. Several studies have shown that insulin resistance is common in heart failure of both ischemic and non-ischemic origin. The exact mechanisms are not known but potentially include both causal and secondary associat
Achievement of Real Paying Capacity in the Context of Analysis of Provision of Obligations of an Insurance Company by Means of its Resources Достижение реальной платежеспособности в разрезе анализа обеспечения обязательств страховой компании за счёт её ресурсов
Sokol Sergey V.
Business Inform , 2013,
Abstract: The article describes requirements to real paying capacity of insurers from the point of view of Ukrainian legislation. It analyses provision of obligations of an insurer by means of its resources. It specifies forms of provision of obligations of an insurance company, which facilitate development of a basis for compensation of losses and satisfaction of creditors’ requirements. It draws a conclusion of a contradiction relevant to paying capacity, which lies in worsening paying capacity in the event of increase of insurance payments and reserves of unearned premiums. В статье изложены требования к реальной платежеспособности страховщиков с позиции законодательства Украины. Проанализировано обеспечение обязательств страховщика за счёт его ресурсов. Определены формы обеспечения обязательств страховой компании, которые способствуют созданию основания для возмещения убытков и удовлетворения требований кредиторов. Подытожено соответствующее платежеспособности противоречие, которое заключается в ухудшении платежеспособности при увеличении страховых платежей и резервов незаработанных премий.

Wu Zhenyun,Sun Changhua,Wu Zhiping Xu Shulian Institute of Psychology,Chinese Academy of Sciences,

心理学报 , 1993,
Abstract: ?he purpose of this study was to compare the age and cross-culturaldifferences of the memory performances, and the training effect of Chineseand Germans across the life span through cognitive training in different his-torical and cultural backgrounds. This study further investigated age andculture-related differences in training transfer on figures. There were 70Chinese and 70 Germans divided into three age groups. The memory trainingof Method of Loci was conducted in Beijing and Berlin. The results indicatedthat the cognitive function of the elderly declined significantly and the deve-lopmental reserve capacity of cognitive function of the elderly were lower thanthat of young adults and adolescents. At pretest, there was no culture-rela-ted difference in all performances between Chinese and Germans. After trai-ning. the performances of the Chinese improved more than that of the Germans.Training exposed cross-cultural differences.

Wu Zhenyun,Sun Changhua,Wu Zhiping,Xu Shulian Institute of Psychology,Chinese Academg of Sciences,

心理学报 , 1992,
Abstract: The study was conducted on memory training with 24 adolescents. 24 young and 22 old subjects using the method of Loci. The purpose of this study focused on comparing the effects of cognitive training on improvement of the memory in different ages with the life span developmental perspective. Further this study investigated the age differences in developmental reserve capdeity of cognitive function and the transfer effect of training. The results indicated that the cog- nitive intervention strategy could improve the memory of the elderly to a certain degree. Meanwhile, it also showed that the result of old adults were obviously worse than that of the young adults and adolescents, and the two latter age groups were similar in develop- mental reserve capacity and the transfer effects of figures.
Practical Use of Stairs to Assess Fitness, Prescribe and Perform Physical Activity Training  [PDF]
Jasem Ramadan Al Kandari, Salman Mohammad, Ruqayyah Al-Hashem, Girma Telahoun, Mario Barac-Nieto
Health (Health) , 2016, DOI: 10.4236/health.2016.813141
Abstract: Aim: Evaluating climbing stairs for prescription and implementation of physical activity regimes. Methods: Healthy females (F, n = 14), and males (M, n = 15) participated. By climbing 100 steps of stairs with 0.173 m height, Heart rate (HR) and oxygen uptake were measured throughout the floors; Blood pressure (BP) was measured at ground and the 5th floors only. Results: Energy increased from 2 to 7.6 was metabolic equivalents (METs = 3.5 ml O2/min.kg) at 17.3 m elevation in 2 min. at the 5th floor, and percent Heart Rate Reserve (%HRR) was 66.17% in F and 48.7% in M, proportional to their aerobic efforts. Average climbing efficiency was 15.8 ± 2.3% (n = 29). Aerobic capacity estimated dividing the highest work rate (17.3 Kg.m/2min.Kg × 0.00239 = 0.0207 Kcal/min.Kg), by fractional effort (F = 0.6617, M = 0.487) and fractional efficiency (0.158), at 5 Kcal/L O2 was 0.040 in F and 0.054 L O2/Kg.min in M. Minimum training intensity reached at the 3rd floor by F. In M the highest %HRR reached was 48.7% at the 5th floor, insufficient for training. Conclusions: Stairs used for submaximal evaluation of aerobic capacity and for target intensity prescription. Training, levels climbed, repetitions per day (if 5, 100 Kcal per day, ascending) and number of days/week are adjusted. Full regime requires up to 7.6 METs, a total of 532 and 140 MET.min/week ascending and descending, respectively. Intensities >7.6 MET, climbing rate should be >8.65 m/min. Limiting ascent to 1 (3.5 METs) or 2 (5.5 METs) floors or only descents (2 - 3 METs) may be used for unfit subjects. This method is useful for those with no access to sophisticated facilities.
Stroke in the Young Adults: 6-Year Case Series of Community Hospital Stroke Unit  [PDF]
S. Anticoli, M. C. Bravi, F. R. Pezzella
Open Journal of Emergency Medicine (OJEM) , 2015, DOI: 10.4236/ojem.2015.33005
Abstract: Stroke etiology in young adults and older patient differs considerably, as well as epidemiology and clinical features vary according to geographical criteria. To improve clinical management and optimize diagnostic work-up of young adults with acute cerebrovascular events, we analyzed retrospectively data of 6-year stroke unit case series. In this hospital case series study, we enrolled 145 patients with acute cerebrovascular events aged 16 to 49, consecutively admitted to a Community Hospital Hub Stroke Unit. We studied risk factors for stroke, the distribution of acute cerebrovascular events, stroke subtype, length of stay and clinical outcome: 70% of patients were admitted for acute ischemic event (45 female-F, 57 male-M), 10.5% intracranial hemorrhages (5F, 10M), 2.7% subarachnoid hemorrhage (2F, 2M), 2% venous sinus thrombosis (3F), 14.5 for acute ischemic attack (12F, 9M). Among ischemic stroke patients, the etiology was as follows: atherothrombosis 29.4%, cardioembolism 19.6%, arterial dissection 13.7%, other determined causes 8.8%, lacunar stroke 5.8%, and undetermined causes 22.54%. 15% of ischemic young patients were treated with r-TPA. The majority of patients returned home at discharge, whereas 30% needed intensive rehabilitation programme to regain independence in the activity of daily living. Dedicated health care programme targeting prevention and optimizing treatment of acute cerebrovascular events in young adults are desirable to improve prognosis among this socioeconomically active age group.
Comportamiento de la enfermedad cerebrovascular en un período de dos a os Behaviour of cerebrovascular disease in a period of two years
Juan Miguel Rodríguez Rueda,Frank Polanco Rodríguez,Luis Orlando Olivera Bacallao,Juan Lázaro Pérez Chávez
Revista Cubana de Medicina Militar , 2006,
Abstract: Se realizó un estudio retrospectivo descriptivo con el objetivo de evaluar el comportamiento de la enfermedad cerebrovascular en Santa Clara en el período 2003-2004. La investigación quedó conformada con 54 pacientes de uno y otro sexos; se emplearon las variables: sexo, raza, edad, antecedentes patológicos personales relacionados con la enfermedad, tipo de accidente vascular encefálico (isquémico y hemorrágico), complicaciones intracraneales, letalidad según tipo de accidente vascular encefálico , estado del egreso (vivo o muerto), causa de muerte y realización o no de necropsia. La enfermedad cerebrovascular predominó en pacientes mayores de 60 a os de edad del sexo masculino, de la raza blanca. Se comprobó una mayor incidencia de los accidentes vasculares encefálicos isquémicos. Se identificaron como complicaciones más frecuentes la bronconeumonía, el coma y las convulsiones. La letalidad fue mayor en los eventos hemorrágicos así como en pacientes que tenían al menos una enfermedad asociada. La sepsis respiratoria constituyó la principal causa de muerte, seguida del tromboembolismo pulmonar. Se utilizaron técnicas estadísticas según estudios descriptivos. A descriptive retrospective study was conducted to assess the behaviour of cerebrovascular disease in Santa Clara province from 2003 to 2004. The research included 54 patients of both sexes. The following variables were used: sex, race, age, personal pathological history related to the disease, type of encephalic vascular accident (ischemic and hemorrhagic), intracranial complications, lethality according to the type of encephalic vascular accident, discharge state (alive or dead), cause of death, and the performing or not of necropsy. There was a predominance of cerebrovascular disease in white male patients over 60 years old. A higher incidence of the ischemic encephalic vascular accidents was proved. Bronchopneumonia, coma and convulsions were the most frequent complications. Lethality was higher in hemorrhagic events as well as in patients with at least an associated disease. Respiratory sepsis was the main cause of death, followed by pulmonary thromboembolism. Statistical techniques were used according to the descriptive studies.
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