Cerebrovascular and brain metabolism reviews最新文献

{"title":"Vascular dementia: a construct in evolution.","authors":"D W Desmond","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Since the late 1800s, when Alzheimer and Binswanger proposed the concept of \"arteriosclerotic brain degeneration,\" there has been an evolution in thinking regarding cerebrovascular disease (CVD) as a basis for dementia. While later work recognized the importance of specific infarct characteristics including volume, multiplicity, and location, recent studies have found that many factors may work in combination with those characteristics to produce dementia, including white matter disease; vascular risk factors such as diabetes; comorbid illnesses, particularly those that might produce cerebral ischemia or hypoxia; genetic factors; and host characteristics such as older age and fewer years of education. Studies of the prevalence of vascular dementia (VaD) have suggested that CVD is second only to Alzheimer's disease as a basis for dementia in Western countries and the most common basis in certain Asian countries, but those studies may have underestimated the frequency of dementia associated with CVD due to a failure to perform brain imaging and decreased survival among patients with CVD. Few studies of the incidence of VaD have been performed, but they have also consistently demonstrated an elevated risk associated with CVD. While certain methodologic issues have contributed to the debate regarding the importance of CVD as a basis for dementia, including variability in the techniques that have been used to characterize brain lesions, assess cognitive function, and diagnose dementia; difficulties inherent in the determination of a causal role for CVD in dementia; and the potential confounding effects of aphasia and depression in patients with stroke, it is clear that VaD remains an important public health problem.</p>","PeriodicalId":9739,"journal":{"name":"Cerebrovascular and brain metabolism reviews","volume":"8 4","pages":"296-325"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19932869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multimodal monitoring and assessment of cerebral haemodynamic reserve after severe head injury.","authors":"M Czosnyka, P J Kirkpatrick, J D Pickard","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>This article contains an overview of selected clinical techniques employed for neurointensive care monitoring and testing of cerebral autoregulation of patients following severe head injury. Multiple modalities are used for monitoring of cerebral haemodynamic reserve, including intracranial pressure, cerebral perfusion pressure (CPP), blood flow velocity (FV) in the middle cerebral artery (MCA), jugular bulb oxygen saturation, laser-Doppler cortical flowmetry, near infrared spectroscopy of cerebral cortex, tissue oxygenation, and microdialysis. Large volumes of information demand specialised computer support for sensible interpretation and filtration of artifacts. Methods of testing of cerebral autoregulatory reserve based on transcranial Doppler ultrasonography are reviewed. Repetitive or continuous assessment is important in practice as autoregulatory reserve may fluctuate in time. Static and dynamic rates of autoregulation show sensitivity to carbon dioxide-induced vasodilatation, but fail to correlate with outcome following head injury. The carotid artery compression test, useful for assessment of patients after subarachnoid haemorrhage, has yet to prove its usefulness in head injury. Continuous waveform analysis of MCA FV and CPP correlates with coma score after resuscitation and outcome and hence may be considered as a robust method for the assessment of autoregulation in ventilated head trauma patients.</p>","PeriodicalId":9739,"journal":{"name":"Cerebrovascular and brain metabolism reviews","volume":"8 4","pages":"273-95"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19933551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cortical thermal clearance as a predictor of imminent neurological deterioration.","authors":"M S Choksey","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Cerebral blood flow (CBF) is vital for the perfusion of brain tissue. It is frequently deranged in acute neurosurgical disorders, particularly subarachnoid haemorrhage and head injury. Despite its importance, in clinical practice the routine measurement of CBF is uncommon, as changes in CBF can occur abruptly. However, a method of CBF monitoring may be potentially useful, particularly if warning could be obtained of impending ischaemia before neurological deterioration. Measurement of tissue thermal clearance has been used as an estimate of local tissue blood flow since 1933. Its history is full of controversy, mostly centred around quantification. The ability of perfused tissues to clear heat is, as a first approximation, the sum of two components: a fixed component related to the constituents of the tissue, primarily the water content, and a variable convective component, related to the local blood flow. The mathematical relationship between flow and the observed increment in thermal clearance is still debatable. Here, the history of thermal clearance is reviewed, and the results of our work with a relatively simple device are described. It consisted of an implantable probe, designed to measure the thermal clearance of the cortical surface in arbitrary clearance units (CU), ranging from 27 CU (cadaveric) to 69 CU (well perfused brain). Pre- and postoperative studies showed that the system was capable of following changes in blood flow rapidly. The cortical thermal clearance (CTC) was monitored postoperatively in 24 patients after aneurysm surgery. Most remained clinically stable and had thermal clearances over 50 CU. In others, however, it was seen that a low-or falling-thermal clearance was associated with development of a neurological deficit. Analysis using receiver operating characteristics curves established that the method had a sensitivity of 0.86 and a specificity of 0.82 in the detection of a contralateral ischaemic motor deficit. No patient in whom the CTC remained above 50 CU ever developed a new neurological deficit, whereas all patients with a CTC below 35 did. The evidence-historical, mathematical, practical, and theoretical-that CTC is closely related to local blood flow is discussed. Changes in thermal clearance have been observed prior to the development of ischaemic neurological deterioration. Detection of imminent ischaemia may become increasingly important as means of improving cortical blood flow become more widely available. Whether such early detection- and subsequent treatment-of ischaemia will result in better patient outcome remains to be established. I believe it will.</p>","PeriodicalId":9739,"journal":{"name":"Cerebrovascular and brain metabolism reviews","volume":"8 3","pages":"230-71"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19837583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The stress gene response in brain.","authors":"S M Massa,&nbsp;R A Swanson,&nbsp;F R Sharp","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Changes in gene expression in the brain in response to adverse conditions, such as ischemia or excitotoxin exposure, may be part of the injury process or represent an adaptive response which may be protective during subsequent stressful events. In this review we have considered the regulation, functions and potential relationships to the pathophysiology of ischemia of several major groups of stress-induced genes, including those of the M(r) 27,000, 32,000 (heme oxygenase), 70,000 and 90,000 heat shock protein families, the glucose-regulated proteins, glucose transporters and ubiquitin. Patterns of gene expression in several injury models, including focal and global ischemia, excitotoxin/ seizure-related injury and hyperthermia are reviewed. In vitro expression studies and the phenomenon of ischemic tolerance are also discussed. It is concluded that stress gene expression provides a useful marker of cellular injury, and that disjunction of mRNA and protein expression may be indicative of imminent death in cells which survive the initial insult. Though other stress proteins may play a role, it seems unlikely that neuronal hsp70 expression is a major contributor to ischemic tolerance.</p>","PeriodicalId":9739,"journal":{"name":"Cerebrovascular and brain metabolism reviews","volume":"8 2","pages":"95-158"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19700448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neuroimaging for differentiating vascular from Alzheimer's dementias.","authors":"J S Meyer,&nbsp;T Shirai,&nbsp;H Akiyama","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Recent advances in the clinical and neuroimaging features of vascular dementia (VAD) versus Alzheimer type dementia (DAT) are described. The lacunar type of VAD, which is often accompanied by silent strokes and a progressive course, is easily confused with DAT. Measurements of cerebral blood flow (CBF) and metabolism (CMR) displayed as brain maps, identify VAD from DAT because of the multifocal and often subcortical nature of the infarcts in VAD, which are strikingly different from the diffuse cortical reductions of CBF and CMR in DAT. Thus, neuroimaging is important for establishing the diagnosis in these two most common forms of dementia in the elderly. A dramatic method for separating VAD from DAT is by utilizing the noninvasive acetazolamide test and xenon contrast CT scanning for measuring the cerebral vasomotor capacitance. In DAT the vasodilator reserve is increased due to the law of initial values. In VAD it is absent or severely blunted so that the differences between the two underlying causes of the dementias become readily apparent.</p>","PeriodicalId":9739,"journal":{"name":"Cerebrovascular and brain metabolism reviews","volume":"8 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"1996-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"20011105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Scientific activities of Professor Lindsay Symon in the field of clinical neurosurgery.","authors":"E Pásztor","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":9739,"journal":{"name":"Cerebrovascular and brain metabolism reviews","volume":"7 4","pages":"280-9"},"PeriodicalIF":0.0,"publicationDate":"1995-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19677631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rodent models of focal ischemia.","authors":"M A McAuley","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Experimental models of focal ischemia have provided an unparalleled insight into the dynamic events that surround ischemic brain injury. The dichotomous capacity of existing rodent models of focal ischemia to provide a controlled environment to examine the pathogenesis of focal ischemia and to allow assessment of the efficacy of potential therapeutic intervention is reviewed. The established rodent model of permanent middle cerebral artery occlusion (electrocoagulation) is critically examined and set against the distinctive features of novel methods that have been developed to reduce invasive surgery and to examine the pathological consequences of reperfusing a previously ischemic area. Emphasis has been placed on the technical requirements of each model that affect outcome and reproducibility.</p>","PeriodicalId":9739,"journal":{"name":"Cerebrovascular and brain metabolism reviews","volume":"7 2","pages":"153-80"},"PeriodicalIF":0.0,"publicationDate":"1995-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18674687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neurogenic control of the cerebral circulation.","authors":"N M Branston","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":9739,"journal":{"name":"Cerebrovascular and brain metabolism reviews","volume":"7 4","pages":"338-49"},"PeriodicalIF":0.0,"publicationDate":"1995-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19677495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The experimental writings of Lindsay Symon.","authors":"K A Hossmann","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":9739,"journal":{"name":"Cerebrovascular and brain metabolism reviews","volume":"7 4","pages":"290-6"},"PeriodicalIF":0.0,"publicationDate":"1995-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"19677633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Functional brain imaging with SPECT in normal aging and dementia. Methodological, pathophysiological, and diagnostic aspects.","authors":"G Waldemar","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>New developments in instrumentation, radiochemistry, and data analysis, particularly the introduction of 99M TC-labeled brain-retained tracers for perfusion studies, have opened up a new era of single photon emission computed tomography (SPECT). In this review critical methodological issues relating to the SPECT instrument, the radioactive tracers, the scanning procedure, the data analysis and interpretation of data, and subject selection are discussed together with the changes in regional cerebral blood flow (rCBF) observed in normal aging. An overview is given of the topography and the pathophysiological and diagnostic significance of focal rCBF deficits in Alzheimer's disease and in other dementia disorders, in which SPECT is capable of early or preclinical disease detection. In Alzheimer's disease, the diagnostic sensitivity and specificity of focal rCBF deficits measured with SPECT and brain-retained tracers are very high, in particular when combined with medial temporal lobe atrophy on CT. Together with neuropsychological testing, SPECT serves to map the topography of brain dysfunction. Thus, in the clinical setting, SPECT provides information that is supplemental to that obtained in other studies. Future applications include neuroreceptor studies and treatment studies, in which SPECT may serve as a diagnostic aid in the selection of patients and as a potential mean for monitoring treatment effects. Although positron emission tomography is the best characterized tool for addressing some of these clinical and research issues in dementia, only the less expensive and technically simpler SPECT technique will have the potential of being available as a screening diagnostic instrument in the clinical setting. It is concluded that, properly approached, functional brain imaging with SPECT represents an important tool in the diagnosis, management, and research of dementia disorders.</p>","PeriodicalId":9739,"journal":{"name":"Cerebrovascular and brain metabolism reviews","volume":"7 2","pages":"89-130"},"PeriodicalIF":0.0,"publicationDate":"1995-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18674688","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}