Can stroke physicians and neuroradiologists identify signs of early cerebral infarction on CT?
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Doctors managing acute stroke are expected to recognise signs of early infarction on CT before choosing thrombolytic treatment, according to recent trials and guidelines. The ability of 13 physicians and two neuroradiologists to recognise early infarct signs and decide whether patients should be randomised in a hypothetical stroke treatment trial was tested. Only 65% of the CT scans from 14 stroke patients were correctly identified as normal or abnormal (95% CI 60-69%). Neither observer experience nor knowledge of symptoms significantly improved recognition of abnormality, although experience did significantly improve the observers' ability to reproduce their results. Parenchymal hypodensity was the least well recognised sign. Only 45% (95% CI 40%-50%) of patients were identified correctly for the hypothetical acute stroke treatment trial. Early infarction on CT is not well recognised even by experienced doctors. Part of the problem may be in understanding the definitions of the extent of infarction. These difficulties should be considered in the design of acute stroke treatment trials and in the introduction of any new acute stroke treatments. (+info)
Should computed tomography appearance of lacunar stroke influence patient management?
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Patients with a lacunar stroke syndrome may have cortical infarcts on brain imaging rather than lacunar infarcts, and patients with the clinical features of a small cortical stroke (partial anterior circulation syndrome, PACS) may have lacunar infarcts on imaging. The aim was to compare risk factors and outcome in lacunar syndrome (LACS) with cortical infarct, LACS with lacunar infarct, PACS with cortical infarct, and PACS with lacunar infarct to determine whether the clinical syndrome should be modified according to brain imaging. As part of a hospital stroke registry, patients with first ever stroke from 1990 to 1998 were assessed by a stroke physician who assigned a clinical classification using clinical features only. A neuroradiologist classified recent clinically relevant infarcts on brain imaging as cortical, posterior cerebral artery territory or lacunar. Of 1772 first ever strokes, there were 637 patients with PACS and 377 patients with LACS who had CT or MRI. Recent infarcts were seen in 395 PACS and 180 LACS. Atrial fibrillation was more common in PACS with cortical than lacunar infarcts (OR 2.3, 95% confidence interval (95% CI) 0.9-5.5), and in LACS with cortical than lacunar infarcts (OR 3.9, 1.2-12). Severe ipsilateral carotid stenosis or occlusion was more common in PACS with cortical than lacunar infarcts (OR 3.5, 1.3-9.5); and in LACS with cortical than lacunar infarcts (OR 3.7, 1.1-12). In conclusion, patients with cortical infarcts are more likely to have severe ipsilateral carotid stenosis or atrial fibrillation than those with lacunar infarcts irrespective of the presenting clinical syndrome. Brain imaging should modify the clinical classification and influence patient investigation. (+info)
Effect of poststroke captopril treatment on mortality associated with hemorrhagic stroke in stroke-prone rats.
(27/13678)
We tested the ability of captopril treatment (50 mg/kg/day p.o.), initiated 2 weeks before stroke or up to 5 days after stroke, to alter the onset of stroke and death after stroke in Kyoto Wistar stroke-prone spontaneously hypertensive rats (SHRsp). The benefits of blood pressure and aldosterone suppression during captopril treatment were assessed. SHRsp developed a 100% mortality rate with intracerebral hemorrhage by 16 weeks of age. Captopril treatment, started 2 weeks before or at the initiation of stroke, suppressed plasma aldosterone and equally prevented mortality to a mean age of >27 weeks. Treatment started 5 days after stroke extended the mean lifespan to >23 weeks. The re-elevation of plasma aldosterone (via osmotic pumps to levels in untreated SHRsp) during captopril treatment, before stroke, allowed stroke to develop. The initiation of the latter manipulation in pre- or poststroke captopril-treated SHRsp at a latter age (23 weeks) didn't alter the lifespan of SHRsp (death occurred at about 28 weeks). The antistroke effects of captopril treatment occurred without an antihypertensive effect, weren't altered by enhancing hypertension during treatment (with dexamethasone), and couldn't be duplicated by antihypertensive treatment with hydralazine. Spironolactone treatment didn't duplicate the effects of captopril. The suppression of plasma aldosterone may retard the onset of stroke in SHRsp during captopril treatment but likely other factors prolong life in pre- and poststroke SHRsp receiving long-term captopril treatment. The observation that spironolactone treatment couldn't duplicate the effects of captopril suggests that aldosterone may facilitate stroke through nongenomic receptor mechanisms. (+info)
The gene encoding atrial natriuretic peptide and the risk of human stroke.
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BACKGROUND: Recent evidence from an animal model of stroke, the stroke-prone spontaneously hypertensive rat, implicated the gene encoding atrial natriuretic peptide (ANP) as a possible candidate contributing to the likelihood of experiencing a stroke. The purpose of the present study was to investigate the role of ANP in the pathogenesis of cerebrovascular accidents in humans. METHODS AND RESULTS: We investigated 2 previously known markers at ANP, G1837A and T2238C, for their possible association with the occurrence of stroke. This was the largest matched case-controlled sample studied thus far; the sample was drawn from a large prospective study (the Physician's Health Study). When assuming a dominant mode of inheritance, a statistically significant positive association was observed for the 1837A allele, indicating an odds ratio of 1.64 (95% confidence interval, 1.01 to 2.65) for stroke. This observation led to the discovery of a new molecular variant in exon 1, G664A, which was responsible for a valine-to-methionine substitution in the proANP peptide. This mutation, which was in linkage disequilibrium with the G1837A marker, was associated with the occurrence of stroke (odds ratio, 2.0; 95% confidence interval, 1.17 to 3.19; P=0.01). CONCLUSIONS: Our findings suggest that molecular variants of the ANP gene may represent an independent risk factor for cerebrovascular accidents in humans. The strong parallelism to the experimental data obtained in the stroke-prone animal model provides assurance for the relevance of our observation. (+info)
Stroke and atrial fibrillation: is stroke prevention treatment appropriate beforehand? SAFE I Study Investigators.
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OBJECTIVE: To undertake a pilot study before conducting a large European multicentre prospective study, to determine the proportion of patients with atrial fibrillation who were not receiving antithrombotic treatment before stroke onset, and their characteristics. DESIGN AND PATIENTS: The stroke in atrial fibrillation ensemble (SAFE) I study was an observational study conducted in 213 patients with atrial fibrillation consecutively admitted in 1997 to three European centres for an acute stroke or transient ischaemic attack (TIA). It was determined whether they were receiving prior antithrombotic treatment. RESULTS: Atrial fibrillation was known before stroke in 148 patients (69.5%). Of 213 patients, 34 (16.0%) were receiving anticoagulation treatment before stroke, but only six had an international normalised ratio between 2. 0 and 3.5; 65 (30.5%) were receiving antiplatelet treatment; and three (1.4%) were receiving both anticoagulation and antiplatelet treatment. Of 137 patients eligible for oral anticoagulation, 108 (78.8%) did not receive treatment. Of 142 patients eligible for any antithrombotic treatment, 62 (43.7%) were not treated. The logistic regression analysis, assuming anticoagulation treatment as a dependent variable, found digoxin treatment, absence of arterial hypertension, mitral stenosis, and cardioversion as independent factors. Assuming any antithrombotic treatment as a dependent variable, previously known atrial fibrillation, lower age, being a non-smoker, and absence of arterial hypertension were found to be independent factors. CONCLUSION: More than half of the patients with atrial fibrillation admitted for acute stroke or TIA were not receiving any antithrombotic treatment beforehand. New onset atrial fibrillation and contraindications account for a minority of non-prescriptions; thus, other reasons should be identified to improve stroke prevention in the community. (+info)
Use of antithrombotic measures for stroke prevention in atrial fibrillation.
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OBJECTIVE: To evaluate appropriateness of antithrombotic use to prevent stroke in atrial fibrillation. DESIGN, PATIENTS: 344 patients with atrial fibrillation, stratified by age, were assessed clinically for contraindications to anticoagulation and stroke risk. The use of warfarin and aspirin was compared with recommendations for anticoagulation derived from pooled clinical trial data. RESULTS: Low risk of stroke was seen in 47 (14%) patients, moderate risk in 213 (62%), and high risk in 84 (24%) patients included in the sample (mean (SD) age 68.4 (17.2) years, 42% men). The proportion of patients requiring anticoagulation varied from 258/344 (75%) to 72/344 (21%) depending upon criteria used, of whom 86/258 (33%) and 36/72 (50%) were receiving warfarin, respectively. Warfarin or aspirin were not being used in 124/297 (42%) patients with moderate to high risk, whereas anticoagulation was being undertaken in 13/47 (27%) patients at low risk of stroke. Antithrombotic use (warfarin or aspirin) was significantly less common in patients over 75 years of age, regardless of absence of contraindications and eligibility according to various criteria (p < 0.001). CONCLUSIONS: A clear need for anticoagulation using clinical criteria existed in about 25% of patients in atrial fibrillation presenting to medical clinics who were at high risk of stroke. Of these, only 50% of eligible patients were being anticoagulated. Appropriate anticoagulation needs to be based on risk assessment rather than age. Consensus is therefore needed on appropriate antithrombotic use in clinical practice. (+info)
Transesophageal echocardiographic detection of cardiac sources of embolism in elderly patients with ischemic stroke.
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OBJECTIVE: The aim of this study was to clarify the role of transesophageal echocardiography in detecting cardiac sources of embolism in elderly stroke patients. METHODS: We performed transesophageal echocardiography in 77 patients > or = 70 years old (mean 76.9) with ischemic stroke and investigated embolic sources. Thirty-seven patients were in sinus rhythm (SR) and 40 in atrial fibrillation (Af). RESULTS: Left atrial spontaneous echo contrast was detected in 73% of Af and in 14% of SR (p<0.01). Left atrial thrombus was present in 10% of Af and none of SR (p<0.05). Patent foramen ovale, atrial septal aneurysm, and aortic atherosclerotic plaque > or = 4.0 mm in thickness in the proximal aortic arch were more commonly found in patients with SR. CONCLUSIONS: In elderly ischemic stroke patients, 1) Left atrial spontaneous echo contrast and thrombus are more commonly detected in patients with Af, reflecting left atrial enlargement and blood stasis, and 2) atrial septal aneurysm, patent foramen ovale and aortic atherosclerotic plaque > or = 4.0 mm in thickness in the proximal aortic arch are important findings in patients with SR. (+info)
Observing the process of care: a stroke unit, elderly care unit and general medical ward compared.
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BACKGROUND AND PURPOSE: Patients on stroke units have better outcomes but it is not known why. We investigated the process of care on a stroke unit, an elderly care unit and a general medical ward. METHODS: Comparison of the three settings was by non-participant observation of 12 patients in each. Data were analysed using multi-level modelling methods. RESULTS: Stroke unit patients spent more time out of bed and out of their bay or room, and had more opportunities for independence than patients on the medical ward. There were more observed attempts on the stroke unit than on the general medical ward to interact with drowsy, cognitively- or speech-impaired patients. Stroke unit patients spent more time with visitors. Most of these aspects of care were also found on the elderly care unit, where patients also spent less time asleep or 'disengaged', more time interacting with nurses, and were given appropriate help more often than those elsewhere. Stroke unit patients received less eye contact, were ignored and treated in a dehumanizing way more frequently and had more negative interactions or activities than those elsewhere. CONCLUSIONS: We have identified some aspects of the process of care which may help explain the improved outcomes on stroke units. These aspects were also observed in the elderly care unit. (+info)