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

Recent advances in the diagnosis and treatment of stroke have justified its management as a medical emergency. This article summarises the current recommendations for the initial management of major types of stroke with emphasis on acute therapy for ischaemic stroke. Recommendations are based on results of well-designed clinical trials. An acute stroke care team and an acute stroke unit should be established in all regional hospitals. Diagnosis of stroke must be accurate. General management aims for prevention and treatment of neurological and systemic complications, whereas specific management varies according to the stroke type and the underlying pathogenic mechanisms. For selected patients with ischaemic stroke, intravenous recombinant tissue plasminogen activator or a modified viper venom within 3 hours of onset, or intra-arterial pro-urokinase within 6 hours may improve functional outcomes. Neurosurgical treatment is indicated for some patients with ischaemic or haemorrhagic strokes. Prevention of recurrence and rehabilitation are the core components of subsequent management.
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PMID:Cerebrovascular disease--advances in management. 1140 77

The safety and efficacy of selective intraarterial administration of urokinase in five male patients, (age range 30 to 65 years, mean 41.2 years), with occlusive stroke involving the carotid territory and a normal cranial computed tomography scan was evaluated. The time elapsed before treatment ranged from one to 10 hours. Digital subtraction angiography disclosed distal internal carotid artery occlusion in one patient and occlusion of the middle cerebral artery or its branches in the others. The urokinase dose ranged from 120,000 to 500,000 units. In two patients who received thrombolytic treatment within three hours of the onset of symptoms, there was a 100% recanalisation associated with excellent neurological recovery. In the remaining three patients, recanalisation rate varied from 0 to 50% with partial recovery in two and no recovery in one patient. None had a haemorrhagic transformation of the infarct. Although no firm conclusions can be drawn because of the small number of patients studied, selective intraarterial urokinase therapy appears to be safe and useful in patients with carotid territory stroke if undertaken early. Only through a multicenter, randomized, controlled trial, enough number of patients can be recruited to verify these observations.
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PMID:Selective intra arterial thrombolysis in acute carotid territory stroke. 1144 35

The authors abstracted the records of 43 patients treated with intra-arterial urokinase for acute ischemic stroke to identify predictors of serious complications. Sixteen (37%) had such a complication. Higher urokinase dose (>1.5 x 10(6) U), higher mean arterial blood pressure before treatment (>130 mm Hg), basilar occlusive strokes, and severe strokes were most predictive of these complications. Although urokinase is no longer manufactured, these findings identify patients at risk for complications from other intra-arterial thrombolytics.
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PMID:Intra-arterial urokinase for acute ischemic stroke: factors associated with complications. 1157 43

In 1995, a two-part randomized trial showed the efficacy of intravenous tissue plasminogen activator (tPA) when given within 3 hours of onset of symptoms of acute ischemic stroke. Two subsequent trials were unable to extend the therapeutic window of intravenous tPA beyond 3 hours. A phase IV study performed by experienced stroke centers showed an acceptably low symptomatic intracerebral hemorrhage rate for intravenous tPA of only 3%, whereas a review of the Cleveland area experience showed a disturbingly high rate of symptomatic intracerebral hemorrhage of 15.7%. The Prolyse in Acute Cerebral Thromboembolism (PROACT) II study showed efficacy of intra-arterial pro-urokinase and intravenous heparin over intravenous heparin alone when given within 6 hours of onset of symptoms to patients with thrombotic occlusion of the proximal middle cerebral artery. Additional controlled investigations of intra-arterial thrombolytic therapy are needed. Neuroprotectants in combination with intravenous tPA have yet to show improved efficacy over the use of tPA alone.
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PMID:New insights on thrombolytic treatment of acute ischemic stroke. 1189 96

Because recent studies have indicated that tissue plasminogen activator (tPA) aggravates neurodegenerative processes in many neural pathologies, we studied whether the endogenous tPA antagonist neuroserpin has a neuroprotective effect in an animal model of focal ischemic stroke. After induction of a focal ischemic stroke in the mouse by occlusion of the middle cerebral artery, we found that microglial cells accumulated in the marginal zone of the infarct are the most important source for both plasminogen activators, tPA and uPA. To investigate the effect of neuroserpin on the size and the histology of the infarct we produced transgenic mice overexpressing neuroserpin approximately sixfold in the nervous system. In the brain of these mice the total tPA activity in the uninjured tissue was strongly reduced. After induction of a focal ischemic stroke in the transgenic mice by a permanent occlusion of the middle cerebral artery (MCA), the infarcts were 30% smaller than in the wild-type mice. Immunohistochemical analyses and in situ hybridization revealed an attenuation of the microglial activation in the reactive zone. Concomitantly, the microglial production of tPA and uPA, as well as the PA-activity in the infarct region was markedly reduced. Thus, our results indicate that neuroserpin reduces microglial activation and, therefore, the PA activity and has a neuroprotective role after focal ischemic stroke.
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PMID:Neuroserpin, a neuroprotective factor in focal ischemic stroke. 1192 37

Pharmacological therapy for acute nonhaemorrhagic stroke has become a reality over the last 5 years. Mechanistically, both thrombolytic (tissue plasminogen activator and urokinase) and antiplatelet (aspirin) monotherapy have demonstrated efficacy. However, unintended actions limit the extent of clinical improvement in each circumstance. For example, in addition to excess bleeding, tissue plasminogen activator therapy has been associated with complement activation, neuronal toxicity and laminin degradation, while aspirin may reduce nitric oxide synthase activity and cerebral blood flow. Attention is now directed toward improving the therapeutic index for each class of agents. Generally, while thrombolytic therapy is focused on developing agents with greater fibrin specificity and safety (that is, a reduction in intracranial haemorrhage rate), the development of antiplatelet agents is primarily focused on achieving greater potency. The latter is being investigated by combining agents with different mechanisms (aspirin and dipyridamole, aspirin and clopidogrel) as well as agents designed to block the glycoprotein IIb/IIIa receptor, the final common pathway for platelet aggregation. Thus, combination therapy using both thrombolytic and antiplatelet agents will further attempt to improve the therapeutic index by increasing potency and improving the safety profile. Anecdotal case studies support the merits of this approach and are consistent with the data reported for myocardial ischaemia and interventional strategies. It is anticipated that drug therapy directed at both thrombolytic and antiplatelet targets will ultimately result in a widened therapeutic window that will allow acute stroke therapy to be administrated to a much greater number of patients than is currently possible.
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PMID:Combining antiplatelet and thrombolytic therapies for stroke. 1193 43

Alteplase (t-PA), a recombinant analogue of human tissue plasminogen activator, became the first genetically engineered thrombolytic approved by the Food and Drug Administration in 1987 for acute myocardial infarction (AMI). In addition to AMI, alteplase is currently approved for the treatment of acute ischemic stroke and pulmonary embolism, and we anticipate approval for catheter clearance in late 2001 in a 2-mg vial configuration. With the withdrawal of human neonatal kidney cell-derived urokinase, alteplase has become an alternative agent in peripheral vascular applications. Because few interventionalists had prior experience with the handling and dosage of alteplase, the Advisory Panel to the Society of Cardiovascular and Interventional Radiology established practice guidelines for use in noncoronary applications. Emerging clinical experience with contemporary dosing regimens shows a safety and efficacy profile similar to urokinase but with significantly reduced drug costs. Tenecteplase (TNK) is a genetically modified version of alteplase. TNK is the only plasminogen activator available that has shown a significantly enhanced safety profile versus alteplase in AMI. Approved for a 5-second, single-bolus injection in AMI, TNK possesses a longer half-life, increased resistance to plasminogen activator inhibitor, and improved fibrin specificity compared with alteplase. Because of its enhanced safety profile, TNK may be a desirable agent for peripheral vascular applications. Initial clinical studies with TNK in acute arterial and venous disease are ongoing. This article outlines the Advisory Panel guidelines for using alteplase and highlights features of tenecteplase.
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PMID:Alteplase and tenecteplase: applications in the peripheral circulation. 1198 95

Rat focal cerebral ischemia induced by occlusion and thrombogenesis of middle cerebral artery(MCAO) was used as experimental model to study the effects of extract of Ginkgo biloba (EGb) and the positive control drugs were urokinase and nimodipine on cerebral infarct size and neurological deficits. The results showed that cerebral ischemia and neurological deficits appeared in rat focal cerebral ischemic models, and the degree was of cerebral ischemia larger in occlusion model than in thrombogenesis model. The cerebral infarct size was significantly smaller and neurological deficits greatly improved at large dose of EGb(200 mg.kg-1, i.v.), the preventive effect appeared to be better than the treatment effect. The positive control drugs urokinase and nimodipine were also shown to distinctly decrease the cerebral infarct size and improve the neurological deficits in the models. Small dose of EGb(100 mg.kg-1, i.v.) was found to decrease the cerebral infarct size of thrombogenesis model, and improve neurological deficits of both thrombogenesis and occlusion model. EGb was also shown to inhibit the thrombogensis of rat common carotid artery stimulated by electrical current in dose-dependent manner. This experiment indicates that EGb might have beneficial effects on prevention and treatment of ischemic stroke and thrombogenesis.
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PMID:[Protective effects of Ginkgo biloba extract on focal cerebral ischemia and thrombogenesis of carotid artery in rats]. 1201 54

Life-threatening, complete middle cerebral artery infarction occurs in up to 10% of all stroke patients. The "malignant media occlusion" is an infarction occupying more than 50% of middle cerebral artery territory. The malignant, space-occupying supratentorial ischemic stroke is characterised by a mortality rate of up to 80%. Several reports indicate, that hemicraniectomy in this situation can be life-saving. Hemicraniectomy increases cerebral perfusion pressure and optimises retrograde perfusion via the leptomeningeal collateral vessels. A case of a patient is presented, having progressive neurological deterioration due to massive cerebral infarctions. The patient rehabilitation was successful. Decompressive surgery is life saving and can also give acceptable functional recovery. Hemorrhagic stroke is due to stroke in 15% of cases and in 10%, it is "spontaneous" intracerebral hematoma. The intracerebral and intraventricular hemorrhage represents one of the most devastating types of stroke associated with high morbidity and mortality. The 30-day mortality rate is 35% to 50% and most survivors are left with a neurological disability. The value of surgical therapy is debatable. The aspiration and urokinase therapy of the hematoma of intracerebral hemorrhage could improve final neurological outcome. Spontaneous, nontraumatic intraventricular hemorrhage frequently carries a grave prognosis. A large part of morbidity after intraventricular hemorrhage is related to intracranial hypertension from hydrocephalus. One patient presented had intracerebral hemorrhage and another had intraventricular hemorrhage treated with urokinase. Rapid and extensive reduction in the amount of intracerebral and intraventricular blood occurred. Urokinase lysis is safe and can be a potentially beneficial intervention in intracerebral and intraventricular hemorrhage. By performing decompressive craniectomy, the neurologists of stroke departments and intensive care units with the neurosurgeons will have to play major role in the management of stroke patients.
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PMID:[New methods of intensive therapy in stroke: hemicraniectomy in patients with complete middle cerebral artery infarction and treatment of intracerebral and intraventricular hemorrhage with urokinase]. 1212 81

Little is known about whether recanalization of carotid territory occlusions by local intra-arterial thrombolysis (LIT) depends on the type of the occluding thromboembolus. We retrospectively analysed the records of 62 patients with thromboembolic occlusions of the intracranial internal carotid artery (ICA) bifurcation or the middle cerebral artery who were undergoing LIT with urokinase within 6 h of symptom onset. We determined the influence of thromboembolus type (according to the TOAST criteria), thromboembolus location, leptomeningeal collaterals, time interval from onset of symptoms to onset of thrombolysis, and patient's age on recanalization. The thromboembolus type was atherosclerotic in six patients, cardioembolic in 29, of other determined etiology in four, and of undetermined etiology in 23 patients. Thirty-three (53%) thromboembolic occlusions were recanalized. The thromboembolus location but not the TOAST stroke type nor other parameters affected recanalization. In the TOAST group of patients with cardioembolic occlusions recanalization occurred significantly less frequently when transoesophageal echocardiography showed cardiac thrombus. The present study underlines the thromboembolus location as being the most important parameter affecting recanalization. The fact that thromboembolic occlusions originating from cardiac thrombi had a lower likelihood of being resolved by thrombolysis indicates the thromboembolus type as another parameter affecting recanalization.
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PMID:Local intra-arterial thrombolysis in the carotid territory: does recanalization depend on the thromboembolus type? 1218 48


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