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(1/610) Prevalence and frequency of microembolic signals in 105 patients with extracranial carotid artery occlusive disease.

Besides the established factors "presence of symptoms" and "degree of stenosis", plaque echolucency is considered to be associated with increased risk of stroke in patients with carotid artery disease. An evaluation was carried out as to whether the prevalence and number of microembolic signals (MES) detected by transcranial Doppler ultrasound were higher in patients with echolucent carotid plaques. One hundred and five patients with carotid artery stenosis from 20%-99% or occlusion underwent clinical investigations, duplex ultrasound of the carotid arteries, and a 1 hour recording from the middle cerebral artery downstream to the carotid artery pathology using the four gate technique. The presence of MES was more frequent and the number greater in symptomatic patients (21 out of 64 patients (33%); mean number of MES in all 64 patients 3.1) than in asymptomatic patients (four out of 41 patients (10%); mean number of MES in all 41 patients 0.3) (p=0.007, and p=0.006, respectively). Echogenicity of the lesions did not affect either number or presence of MES. Positivity for MES and the number of MES increased with increasing degree of stenosis (both p=0.002). Four out of 12 patients with carotid artery occlusion showed MES. No MES could be detected in carotid artery stenosis below 80%. There was a decline in positivity of MES and of the number of MES with the time after the ischaemic event. After 80 days or more after the index event, only one patient showed MES. In conclusion, increasing degree of stenosis and presence of symptoms similarly affect macroembolic and microembolic risk. Thus MES may be a surrogate parameter for risk of stroke. The presence of MES in a few asymptomatic patients suggests that clinically silent circulating microemboli may give additional information on the pending embolic potential of carotid artery stenoses. Echolucency of the plaque was not related to an increased number of MES.  (+info)

(2/610) Endovascular arterial occlusion accomplished using microcoils deployed with and without proximal flow arrest: results in 19 patients.

BACKGROUND AND PURPOSE: Prior to their relatively recent FDA approval, detachable balloons for endovascular arterial occlusion had been available on only a limited basis. We evaluated the feasibility of permanent endovascular carotid and vertebral artery occlusion using microcoils deployed with and without proximal flow arrest in 19 patients. METHODS: Permanent endovascular occlusion was performed in 19 arteries of 19 patients. The treated lesions included nine aneurysms, one carotid-cavernous fistula/pseudoaneurysm, seven neoplasms, and two dissections. Nondetachable balloons were used to arrest proximal blood flow during occlusion of only six arteries. Anticoagulation (heparin, 5000 U IV) was used during occlusion of 18 arteries. Three to 88 coils were used per lesion. Complex fibered platinum microcoils were used for all cases, and GDCs were also used in two patients. RESULTS: Sixteen patients had no new neurologic deficits after arterial occlusion. No patient had an acute event that suggested an embolic complication. Coils provided rapid and durable arterial occlusion in 17 patients. In both patients with acute carotid artery rupture, large numbers of coils placed during flow arrest failed to produce complete occlusion, which was accomplished subsequently with detachable balloons. One of these patients incurred a fatal hemispheric infarct after occlusion. One patient treated for a ruptured posterior inferior cerebellar artery aneurysm by vertebral artery occlusion continued to have progressive neurologic deficits. One patient with a cavernous aneurysm had upper extremity weakness and mild dysphasia 24 hours after internal carotid artery occlusion. CONCLUSION: In our small series, microcoils were found to be safe and effective for neurovascular occlusion. When both intravenous heparin (5000 U IV bolus) and heparinized catheter flush solutions (5000 U/L) are used, flow arrest during coil placement is unnecessary to prevent clinically apparent embolic complications.  (+info)

(3/610) Transesophageal echocardiographic detection of cardiac sources of embolism in elderly patients with ischemic stroke.

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)

(4/610) Intra-arterial cerebral thrombolysis for acute ischemic stroke in a community hospital.

BACKGROUND AND PURPOSE: Advances in thrombolytic therapy, brain imaging, and neurointerventional techniques provide new therapeutic options for acute stroke. Intra-arterial thrombolysis has proved to be a potent therapeutic tool. To show that this procedure can be performed in community hospitals, we describe our experience with a group of 11 patients treated for middle cerebral artery occlusions. METHODS: Twenty-two patients seen during a period of 1 year with clinical findings of acute major-vessel stroke met screening criteria and were evaluated under an institutional review board-approved protocol. After CT scanning, 17 of those patients met strict criteria, gave informed consent, and underwent angiography. Eleven patients had M1 and M2 middle cerebral artery occlusions and received local thrombolytic therapy with urokinase. Recanalization efficacy, complications, and outcome data were compiled. RESULTS: The average score on the National Institutes of Health Stroke Scale was 22.2 at the onset of treatment and 12.5 after therapy, with 91% of patients showing neurologic improvement. Complete (TIMI 3) recanalization occurred in 73% of cases and partial recanalization (TIMI 2) in 18%. At the 90-day follow-up evaluation, 56% of patients had good outcomes (modified Rankin score, 0 to 1). One intracranial hemorrhage occurred. CONCLUSION: Intra-arterial thrombolysis can be performed in a community hospital by radiologists with interventional and neuroradiologic skills given appropriate institutional preparation.  (+info)

(5/610) Recent heavy drinking of alcohol and embolic stroke.

BACKGROUND AND PURPOSE: Epidemiological evidence suggests that heavy alcohol consumption increases the risk for ischemic stroke, whereas light-to-moderate alcohol intake decreases the risk, but the role of different drinking patterns has remained unclear. We investigated recent light, moderate, and heavy alcohol drinking and former heavy drinking as risk factors for acute ischemic brain infarction by etiological subtype of stroke. METHODS: We compared 212 consecutive patients aged between 16 and 60 years, who were completely evaluated for the etiology of their ischemic stroke, with 274 control subjects admitted to the emergency unit of the same hospital. ORs, as estimates of multivariate relative risks (RRs), and 95% CIs after adjustment for possible confounding variables were calculated by logistic regression. The ORs were adjusted for age, sex, body mass index, hypertension, diabetes, hyperlipemia, current smoking, and history of migraine. RESULTS: Recent heavy drinking but not former heavy drinking was an independent risk factor for stroke (RR 1.82, 95% CI 1.08 to 3.05). Consumption of 151 to 300 g and >300 g alcohol within the week preceding the onset of stroke significantly increased the risk for cardioembolic and cryptogenic stroke. Consumption of >40 g alcohol within the preceding 24 hours increased the risk for cardiogenic embolism to the brain among those who had a high-risk source (RR 4.75, 95% CI 1.23 to 18.4), the risk for tandem embolism among those who had prominent large-artery atherosclerosis (RR 7.68, 95% CI 1.82 to 32.3), and the risk for cryptogenic stroke (RR 3.84, 95% CI 1.69 to 8.71). Light drinking did not increase the risk for stroke. CONCLUSIONS: We conclude that acute drinking of intoxicating amounts of alcohol may trigger the onset of embolic stroke among subjects who have a source of thrombus in the heart or the large arteries.  (+info)

(6/610) Multivariable analysis of predictive factors related to outcome at 6 months after intra-arterial thrombolysis for acute ischemic stroke.

BACKGROUND AND PURPOSE: Recent reports have suggested that a rapid assessment of pretreatment residual cerebral blood flow (CBF) could be used to optimize selection criteria for thrombolysis in patients with acute ischemic stroke to improve clinical outcome. We investigated retrospectively residual CBF and other clinical factors related to outcome at 6 months after intra-arterial thrombolysis by using multivariable analysis. METHODS: Seventy-six patients received intra-arterial thrombolysis within 6 hours of symptom onset. The multiple regression method was used to analyze associations between the modified Rankin scale (MRS) at 6 months after treatment and clinical factors including age, infarction type, duration of ischemia, dose of urokinase, degree of recanalization, hemorrhage, National Institutes of Health Stroke Scale score (NIHSSS), and residual CBF evaluated by pretreatment single-photon emission-computed tomography; these values were assessed with the use of the regional-to-cerebellar activity (R/CE) ratio of ischemic region to cerebellum and asymmetry index. RESULTS: MRS at 6 months was good (0 to 3) in 65% and poor (4 to 6) in 35%. Factors significantly related to MRS at 6 months were R/CE ratio (P<0.0001), NIHSSS at baseline and the following day (P<0.0001), cardioembolic infarction (P=0.0014), age (P=0.0074), and recanalization grade (P=0. 007). NIHSSS of >20, R/CE ratio of <0.35, cardioembolic infarction, incomplete recanalization (grade <3), and older age (>75 years) were determined to be significant independent predictors of poor outcome. CONCLUSIONS: The residual CBF, neurological score at baseline and the following day, age, and recanalization grade correlated significantly with long-term outcome. The NIHSSS of >20 and R/CE ratio of <0.35 were determined to be significant independent predictors of poor outcome by multivariable analysis.  (+info)

(7/610) Preventive health care, 1999 update: 2. Echocardiography for the detection of a cardiac source of embolus in patients with stroke. Canadian Task Force on Preventive Health Care.

OBJECTIVE: To develop guidelines for the use of echocardiography in the investigation of patients with stroke. OPTIONS: (1) Routine transthoracic echocardiography (TTE); (2) routine transesophageal echocardiography (TEE); (3) routine TTE followed by TEE if the TTE findings are noncontributory; (4) selective TTE or TEE in patients with cardiac disease who would not otherwise receive anticoagulant therapy. OUTCOMES: This article reviews the available evidence on the yield of TTE and TEE in detecting cardiac sources of cerebral emboli in patients with stroke, the effectiveness of treatment for cardiac sources of emboli and the effectiveness of screening echocardiography for secondary stroke prevention. EVIDENCE: MEDLINE was searched for relevant articles published from January 1966 to April 1998; also reviewed were additional articles identified from the bibliographies and citations obtained from experts. BENEFITS, HARMS AND COSTS: Echocardiography can detect intracardiac masses (thrombus, vegetation or tumour) in about 4% (with TTE) to 11% (with TEE) of stroke patients. The yield is lower among patients without clinical evidence of cardiac disease by history, physical examination, electrocardiography or chest radiography (less than 2%) than among patients with clinical evidence of cardiac disease (less than 19%). The risks of echocardiography to patients are small. TTE has virtually no risks, and TEE is associated with cardiac, pulmonary and bleeding complications in 0.18%. Patients with an identified intracardiac thrombus are at increased risk for embolic events (absolute risk uncertain, range 0%-38%), and this appears to be reduced with anticoagulant therapy (absolute risk reduction uncertain). Anticoagulant therapy carries a risk of major hemorrhage of 1% to 3% per year. The overall effectiveness of echocardiography in the prevention of recurrent stroke is unknown. VALUES: The strength of evidence was evaluated using the methods of the Canadian Task Force on Preventive Health Care. RECOMMENDATIONS: There is fair evidence to recommend echocardiography in patients with stroke and clinical evidence of cardiac disease by history, physical examination, electrocardiography or chest radiography (grade B recommendation). There is insufficient evidence to recommend for or against TEE in patients with normal results of TTE (grade C recommendation). There is insufficient evidence to recommend for or against routine echocardiography in patients (including young patients) without clinical cardiac disease (grade C recommendation). Routine echocardiography is not recommended for patients with clinical cardiac disease who have independent indications for or contraindications to anticoagulant therapy (grade D recommendation). There is fair evidence to recommend anticoagulant therapy in patients with stroke and intracardiac thrombus (grade B recommendation). There is insufficient (no) evidence to recommend for or against any specific therapy for patent foramen ovale (grade C recommendation). VALIDATION: The findings of this analysis were reviewed through an iterative process by the members of the Canadian Task Force on Preventive Health Care.  (+info)

(8/610) Relationship between cardiopulmonary bypass flow rate and cerebral embolization in dogs.

BACKGROUND: Cerebral embolization is a primary cause of cardiac surgical neurologic morbidity. During cardiopulmonary bypass (CPB), there are well-defined periods of embolic risk. In theory, cerebral embolization might be reduced by an increase in pump flow during these periods. The purpose of this study was to determine the CPB flow-embolization relation in a canine model. METHODS: Twenty mongrel dogs underwent CPB at 35 degrees C with alpha-stat management and a fentanyl-midazolam anesthetic. In each animal, CPB flow was adjusted to achieve a mean arterial pressure of 65-75 mmHg. During CPB, an embolic load of 1.2 x 10(5) 67 microm fluorescent microspheres was injected into the arterial inflow line. Before and after embolization, cerebral blood flow was determined using 15-microm microspheres. Tissue was taken from 12 brain regions and microspheres were recovered. The relation between pump flow and embolization/g of brain was determined. RESULTS: The mean arterial pressure at embolization was 67 +/-4 mmHg, and the range of pump flow was 0.9-3.5 l x min(-1)x m(-2). Cerebral blood flow was independent of pump flow. At lower pump flow, the percentage of that flow delivered to the brain increased. There was a strong inverse relation between pump flow and cerebral embolization (r = -0.708, P < 0.000 by Spearman rank order correlation). CONCLUSIONS: Cerebral embolization is determined by the CPB flow. At an unchanged mean arterial pressure, as pump flow is reduced, a progressively greater proportion of that flow is delivered to the brain.  (+info)