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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Stroke is the third leading cause of death and an important cause of longterm disability. Up to 10% of stroke patients is younger than 45 years old. In the present study we measured and compared TF and TFPI concentrations in 50 ischemic stroke patients up to the age of fifty and in 30 control subjects matched for age. TF concentration was significantly higher in ischemic stroke patients, TFPI concentration did not differ compared to controls. No relationship was established between TF and TFPI in relation to clinical subtypes of stroke, sex, smoking, plasma cholesterol level, hypertension, previous stroke.
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PMID:[Tissue factor and it's inhibitor in patients up to 50 years of age with ischemic stroke]. 1132 May 86

Acute stroke is one of the three major causes of death and disability in the United States. Now that new, and possibly effective therapy is becoming available, accurate, rapid diagnosis is important to provide timely treatment, while avoiding the risk of complications from unnecessary intervention. Our objective was to test the hypothesis that use of echo-planar (EPI) diffusion-weighted imaging (DWI) is more accurate than conventional T2 weighted MRI in predicting progression to stroke in patients with acute ischemic neurologic deficits. We studied 134 patients presenting with acute neurologic deficits to a community hospital emergency room with both conventional MRI and DWI within 72 h of the onset of the acute deficit. We found DWI significantly more sensitive to permanent neurologic deficit at discharge (sensitivity 0.81) than conventional MRI (sensitivity 0.41). When available, DWI should be considered for routine use in patients being imaged for acute stroke.
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PMID:The value of diffusion-weighted imaging for prediction of lasting deficit in acute stroke: an analysis of 134 patients with acute neurologic deficits. 1146 53

Diffusion-weighted single-shot EPI (sshEPI) is one of the most important tools for the diagnostic assessment of stroke patients, but it suffers from well known artifacts. Therefore, sshEPI was combined with SENSitivity Encoding (SENSE) to further increase EPI's potential for stroke imaging. Eight healthy volunteers and a consecutive series of patients (N = 8) with suspected stroke were examined with diffusion-weighted SENSE-sshEPI using different reduction factors (1.0 < or = R < or = 3.0). Additionally, a high-resolution diffusion-weighted SENSE-sshEPI scan was included. All examinations were diagnostic and of better quality than conventional sshEPI. No ghostings or aliasing artifacts were discernible, and EPI-related image distortions were markedly diminished. Chemical shift artifacts and eddy current-induced image warping were still present, although to a markedly smaller extent. Measured direction-dependent diffusion-coefficients and isotropic diffusion values were comparable to previous findings but showed less fluctuation. We have demonstrated the technical feasibility and clinical applicability of diffusion-weighted SENSE-sshEPI in patients with subacute stroke. Because of the faster k-space traversal, this novel technique is able to reduce typical EPI artifacts and increase spatial resolution while simultaneously remaining insensitive to bulk motion.
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PMID:Improved diffusion-weighted single-shot echo-planar imaging (EPI) in stroke using sensitivity encoding (SENSE). 1155 Feb 48

Information about the incidence and outcome of stroke subtypes is necessary to understand the likely impact of stroke prevention and treatment strategies. The purpose of this study was to determine the incidence and outcome of subtypes of cerebral infarction (CI). All strokes occurring in a population of 133816 in Melbourne, Australia, during a 12-month period of 1996 and 1997 were identified and cases of CI subtyped according to the Oxfordshire Community Stroke Project classification. 276 'first-ever-in-a-lifetime' stroke cases were registered. CI accounted for 72% of cases. Annual incidence rates per 100000 persons adjusted to the 'world' population were 11 (95% CI, 4-18) for TACI, 25 (95% CI, 15-35) for PACI, 17 (95% CI, 9-25) for POCI and 18 (95% CI, 10-26) for LACI. 28-day case fatality was highest for TACI (35%; 95% CI, 19-51%) and first year recurrence rate highest for PACI (17%; 95% CI, 8-26%). TACI had the poorest functional outcome at 3 and 12 months. These findings are similar to those of two previous studies conducted in the northern hemisphere.
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PMID:Incidence and outcome of subtypes of ischaemic stroke: initial results from the north East melbourne stroke incidence study (NEMESIS). 1249 23

Diffusion-weighted MR imaging (DWI) is particularly sensitive for the detection of acute stoke. Until recently, DWI was performed with EPI technology. We compared 18 patients with clinical suspicion of acute stroke on a standard 1.5T unit and an open low-field MR scanner. Eighteen patients with 20 lesions of acute stroke were studied retrospectively with DWI and ADC mapping on both systems. The technique used was a rotating fast-spin echo T2 at low-field and an EPI sequence at 1.5T. Both examinations were performed within 24 hours and analyzed by two neuroradiologists. We obtained the same results on DWI sequences on both systems, regarding high intensity lesions on DWI. Interpretation of the ADC maps proved to be difficult on low-field MR near the lateral ventricles (3/18). We experienced the same difficulty of interpretation at low and high field in the cerebellum, in the temporal fossa and in cortex situated near bone, due to susceptibility artifacts. Chronic lesions were better visualized at low than at high field. In our opinion, DWI on a low-field open MR scanner is a good technique to evaluate subacute stroke and was as reliable as when performed on a 1.5T MR system.
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PMID:Diffusion weighted MR imaging on a low-field open magnet. Comparison with findings at 1.5T in 18 patients with cerebral ischemia. 1262 88

There is doubt as to whether acute haemorrhage is visible on MRI. We carried out MRI within 6 h of symptom onset on five patients with minor (low Hunt and Hess grades 1 or 2) subarachnoid haemorrhage (SAH) diagnosed by CT to search for any specific pattern. We used our standard stroke MRI protocol, including multiecho proton density (PD)- and T2-weighted images, echoplanar (EPI) diffusion- (DWI) and perfusion- (PWI) weighted imaging, and MRA. In all cases SAH was clearly visible on PD-weighted images with a short TE. In four patients it caused a low-signal rim on the T2*-weighted source images of PWI, and DWI revealed high signal in SAH. In the fifth patient SAH was perimesencephalic; susceptibility effects from the skull base made it impossible to detect SAH on EPI DWI and T2*-weighted images. Perfusion maps were normal in all cases. MRA and conventional angiography revealed an aneurysm in only one patient. Stroke MRI within 6 h of SAH thus shows a characteristic pattern.
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PMID:MRI in acute subarachnoid haemorrhage; findings with a standardised stroke protocol. 1465 34

Computed tomography (CT) is the method of choice to detect acute subarachnoid hemorrhage (SAH). The sensitivity of CT has been reported to range from 85 to 100 %. Magnetic resonance imaging (MRI) using FLAIR sequences shows a comparable sensitivity in acute SAH and in some cases can even be superior to CT. However, additional proton density weighted (PDW) TSE sequences or 3D-FLAIR sequences should be used to avoid false-positive results caused by flow artifacts. Conventional T (1)- or T (2)-weighted SE sequences or susceptibility weighted T (2)* or EPI sequences used for the diagnosis of intracerebral hemorrhage do not detect SAH reliably enough. In subacute SAH, starting from day 5 after the suspected hemorrhage, the sensitivity of MRI is clearly superior to CT. Patients with suspected ischemic stroke scheduled for the initial evaluation by MRI no longer need additional CT studies to rule out subarachnoid hemorrhage as long as the MRI protocols are adequate and the radiologist has the necessary experience.
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PMID:[Magnetic resonance imaging of subarachnoid hemorrhage]. 1508 73

We evaluate the results of stenting and angioplasty on carotid bifurcation stenotic lesions using protection systems, emphasizing the indications and technical aspects. Seventy-nine patients, mean age 64.5 years were treated from February,1998 to March, 2003. All patients were included in NASCET study criteria. Forty three patients were treated without the protection systems and thirty six were treated with carotid protection filtering system (Angioguard, EPI). Technical success and 6-months carotid Doppler ultrasound follow-up showing stent patency were achieved in all patients. One major stroke and one death due to intracranial reperfusion bleeding occurred in patients treated without cerebral protection devices. Only one patient presenting hyper perfusion syndrome improving after 7 days, was found in the group treated with the cerebral protection filter mechanism, no other neurologic symptom or death occurred in this group. Stenting and angioplasty with protection systems for thromboembolic debris is a safe endovascular method to treat stenotic lesions in the carotid bifurcation with low morbidity and mortality.
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PMID:Endovascular treatment of carotid artery stenosis: retrospective study of 79 patients treated with stenting and angioplasty with and without cerebral protection devices. 1560 61

Perfusion-weighted imaging (PWI) measures can predict tissue outcome in acute ischemic stroke. Accuracy might be improved if differential tissue susceptibility to ischemia is considered. We present a novel voxel-by-voxel analysis to characterize cerebral blood flow (CBF) separately in gray (GM) and white matter (WM). Ten patients were scanned with inversion-recovery spin-echo EPI (IRSEPI), diffusion-weighted imaging (DWI), PWI<6 h from onset and fluid attenuated inversion-recovery (FLAIR) at 30 days. Image processing included coregistration to PWI, automatic segmentation of IRSEPI into GM, WM and CSF and semiautomatic segmentation of DWI/FLAIR to derive the acute and 30-day lesions. Five tissue compartments were defined: (1) 'Core' (abnormal acutely and at 30 days), (2) 'Growth' (or 'infarcted penumbra', abnormal only at 30 days), (3) 'Reversed' (abnormal acutely but normal at 30 days), (4) 'MTT-Delayed ' (tissue with delayed mean transit time but not part of the acute or 30-day lesion), and (5) 'Normal' brain. Cerebral blood flow in GM and WM of each compartment was obtained from quantitative maps. Gray matter and WM mean CBF in the growth region differed by 5.5 mL/100 g min (P=0.015). Mean CBF also differed significantly within normal and MTT-Delayed compartments. The difference in the reversed region approached statistical significance. In core, GM and WM CBF did not differ. The results suggest separate ischemic thresholds for GM and WM in stroke penumbra.
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PMID:A novel method to derive separate gray and white matter cerebral blood flow measures from MR imaging of acute ischemic stroke patients. 1588 45

Vascular events commonly recur in stroke patients on aspirin, and may reflect incomplete inhibition of platelet function with aspirin therapy. The platelet function analyser (PFA-100) activates platelets by aspirating a blood sample at a moderately high shear rate through a capillary to a biologically active membrane with a central aperture. The membrane is coated with collagen, and either ADP (C-ADP) or epinephrine (C-EPI). The time taken for activated platelets to adhere, aggregate, and occlude the aperture is called the closure time. Previous studies have shown that aspirin prolongs the C-EPI closure time, without prolongation of the C-ADP closure time, in the majority of control subjects. We hypothesised that the PFA-100 would provide a sensitive assay for the detection of early and convalescent phase cerebrovascular disease (CVD) patients who had incomplete inhibition of platelet function with aspirin. We investigated potential cyclooxygenase-dependent and -independent mechanisms that might influence the responsiveness to aspirin using the PFA-100. Patients were studied during the early (< or = 4 weeks, n=57) and convalescent phases ((< or = 3 months, n=46) after ischaemic stroke or TIA. To investigate potential mechanisms that could contribute to aspirin responsiveness on the PFA-100, we measured von Willebrand factor antigen levels, and carried out platelet aggregometry experiments in platelet-rich plasma in response to sodium arachidonate (1 mM) and ADP (5 microM). Sixty percent of patients in the early phase and 43% of patients in the convalescent phase did not have prolonged C-EPI closure times on 75-300 mg of aspirin daily, and were defined as aspirin non-responders. Median C-ADP closure times were significantly shorter in aspirin non-responders than aspirin-responders in both the early and convalescent phases after symptom onset (P=0.008), suggesting platelet hyper-reactivity to collagen or ADP in the aspirin non-responder subgroup. There was a significant inverse relationship between plasma von Willebrand factor antigen levels and C-EPI closure times in both early and convalescent phase CVD patients (P=0.008). Mean von Willebrand factor antigen levels were significantly higher in aspirin non-responders than aspirin responsive patients in the early (P=0.001), but not convalescent phase (P=0.2) after stroke and TIA. None of the patients studied were defined as being aspirin-resistant using sodium arachidonate- or ADP-induced platelet aggregometry. A large proportion of ischaemic CVD patients have incomplete inhibition of platelet function with low to medium dose aspirin using the PFA-100. The results suggest that cyclooxygenase-independent mechanisms, including elevated von Willebrand factor antigen levels, play an important role in mediating aspirin non-responsiveness on the PFA-100.
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PMID:Assessment of the antiplatelet effects of low to medium dose aspirin in the early and late phases after ischaemic stroke and TIA. 1601 77


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