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

Cerebral vasospasm and related ischemic stroke continue to be significant complicating factors in the course of many patients with subarachnoid hemorrhage from berry aneurysm rupture. The risk of this well-recognized but poorly understood complication can be estimated on the basis of patient medical history, neurologic examination, and head CT findings. Every patient with possible risk needs specialized neurologic intensive care unit care after aneurysm obliteration. Surgical and pharmacologic wash-out of subarachnoid blood around the basal arteries, proper management of intracranial pressure and fluid status, hyponatremia, hypomagnesemia, and fever, as well as use of calcium channel blockers, have been considered helpful in patient management prior to and with the symptomatic vasospasm development. Transcranial Doppler (TCD) ultrasound is important in detecting vasospasm before the patient suffers ischemic neurologic deficit or infarct. Elevated TCD velocities often initiate the use of triple-H (HHH: hypertension, hemodilution, and hypervolemia) therapy and subsequently guide it. Up to the end of the first 3 weeks after subarachnoid hemorrhage and aneurysm obliteration, development of any focal neurologic deficit or mental deterioration, unless convincingly proven otherwise, is assumed to be from cerebral vasospasm. When a hemodynamically significant vasospasm in the arterial segments of clinical concern is suggested, emergency cerebral angiography with balloon dilatation angioplasty or intra-arterial infusion of vasodilating agents may be helpful in relieving ischemic symptoms.
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PMID:Cerebral Vasospasm Following Subarachnoid Hemorrhage. 1219 10

The purpose of this study was to critically analyze the effectiveness of two tools used by nurses to assess neurological status of individuals at risk of developing cerebral vasospasm following aneurysmal subarachnoid hemorrhage due to aneurysm rupture. Early detection of vasospasm provides an opportunity for prompt treatment so that further ischemia or infarction can be prevented. We hypothesized that the National Institutes of Health Stroke Scale would detect symptomatic vasospasm earlier than the standard neurological record currently used in the practice setting of a tertiary care teaching hospital. Thirty participants were entered into the study, and a differential diagnostic process identified 15 with symptomatic vasospasm. Quantitative prospective and retrospective analysis showed that there was no statistical difference between the two scales in early detection of vasospasm. This finding may partially be explained by the clinical similarities between the vasospasm and nonvasospasm groups and by the challenges experienced by nurses in administering the stroke scale. Clinically relevant observations suggested the stroke scale was more effective in the assessment of focal symptoms. Qualitative content analysis of nursing notes also provided insight into clinical findings not captured on either scale regarding generalized changes such as restlessness, impulsiveness, and unusual behavior. This study demonstrates the need to develop a more appropriate tool for early detection of vasospasm.
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PMID:Comparison of a standard neurological tool with a stroke scale for detecting symptomatic cerebral vasospasm. 1250 15

Patients with occult pituitary adenomas infrequently present with pituitary apoplexy. Precipitation of pituitary apoplexy by gonadotropin releasing hormone or gonadotropin releasing hormone agonists has been described. The pathophysiologic mechanism by which these agents induce apoplexy remains unclear. We describe a case of pituitary apoplexy in a young woman receiving leuprolide in preparation for ovum donation. Severe hyponatremia, cerebral vasospasm and infarction, and diabetes insipidus complicated this patient's prolonged hospital course. To our knowledge, pituitary apoplexy after gonadotropin releasing hormone agonist use for ovum donation has not been previously described. The use of leuprolide or other gonadotropin releasing hormone agonists for pituitary down-regulation in conjunction with ovarian stimulation can have serious consequences in women harboring unrecognized pituitary adenomas. Thorough endocrine screening should be performed prior to initiating therapy.
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PMID:Pituitary apoplexy after leuprolide injection for ovum donation. 1250 7

Although cocaine-induced constriction of cerebral vessels may play an important negative role in the pathogenesis of cocaine-related stroke, the mechanism underlying the vasospasm remains unclear. This study investigated the role of endothelin-1 in mediating the spasm. Intracisternal cocaine infusion (10 microl/h via osmotic pump) into the cisterna magna of rabbits induced time- and concentration-dependent spasm. Maximal spasm was achieved with 100 microM cocaine infusate, and was observed as early as 0.5 days and reached a maximum at 2 days. Coinfusion of 100 microM cocaine with the endothelin receptor antagonist PD145065 (100 microM) prevented the spasm. Cerebral spinal fluid levels of cocaine and benzoylecgonine, a major cocaine metabolite, were below the limit of assay detection. This study demonstrates the novel finding that endothelin-1 mediates cocaine-induced cerebral vasospasm.
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PMID:Cocaine-induced endothelin-1-dependent spasm in rabbit basilar artery in vivo. 1254 74

Cerebral vasospasm is a recognised but poorly understood complication for many patients who have aneurysmal subarachnoid haemorrhage and can lead to delayed ischaemic neurological deficit (stroke). Morbidity and mortality rates for vasospasm are high despite improvements in management. Since the middle of the 1970s, much has been written about the treatment of cerebral vasospasm. Hypervolaemia, hypertension, and haemodilution (triple-H) therapy in an intensive-care setting has been shown in some studies to improve outcome and is an accepted means of treatment, although a randomised controlled trial has never been undertaken. In this review, the rationale for this approach will be discussed, alongside new thoughts and future prospects for the management of this complex disorder.
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PMID:Triple-H therapy in the management of aneurysmal subarachnoid haemorrhage. 1450 83

The difficult types of preeclampsia and eclampsia are presented with the neurological symptoms. The break of cerebral autoregulation mechanism plays the most important role in pathogenesis of cerebral vasospasm. Nevertheless, eclampsia isn't just an ordinary hypertensive encephalopathy because other pathogenic mechanisms are involved in its appearance. The main neuropathologic changes are multifocal vasogenic edema, perivascular multiple microinfarctions and petechial hemorrhages. Neurological clinical manifestations are convulsions, headache, visual disturbances and rarely other discrete focal neurological symptoms. Eclampsia is a high-risk factor for onset of hemorrhagic or ischemic stroke. This is a reason why neurological diagnostic tests are sometimes needed. The method of choice for evaluation of complicated eclampsia is computerized brain topography that shows multiple areas of hypodensity in occipitoparietal regions. These changes are focal vasogenic cerebral edema. For differential diagnosis of eclampsia and stroke other diagnostic methods can be used--fundoscopic exam, magnetic resonance brain imaging, cerebral angiography and cerebrospinal fluid exam. The therapy of eclampsia considers using of magnesium sulfate, antihypertensive, anticonvulsive and antiedematous drugs.
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PMID:[Neurologic aspects of eclampsia]. 1460 66

Inhibitors of phosphodiesterases 3 and 4, the main cyclic AMP (cAMP) degrading enzymes in arteries, may have therapeutic potential in cerebrovascular disorders. We analysed the effects of such phosphodiesterases in guinea pig cerebral arteries with organ bath technique and cyclic nucleotide assays. Guinea pig and human cerebral arteries were used for phosphodiesterase assays. Cilostazol (6-[4-(1-cyclohexyl-1H-tetrazol-5-yl)butoxy]-3,4-dihydro-2(1H)-quinolinone), a phosphodiesterase 3 inhibitor, was compared to conventional phosphodiesterase 3 and 4 inhibitors. Phosphodiesterases 3 and 4 were the major contributors to total cAMP hydrolysis in the arteries examined. The phosphodiesterase 3 inhibitors additionally attenuated cyclic GMP (cGMP) hydrolysis, but relaxant responses were not dependent on an intact endothelium or on the nitric oxide-cGMP pathway. Conversely, the phosphodiesterase 4 inhibitor used was endothelium-dependent and affected by cGMP levels. This suggests that phosphodiesterase 3 inhibitors are still effective under conditions with possible dysfunctional nitric oxide-cGMP pathway, such as in ischemic stroke or cerebral vasospasm.
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PMID:Analysis of the effects of phosphodiesterase type 3 and 4 inhibitors in cerebral arteries. 1506 60

Eleven patients with primary thunderclap headache (TCH) were treated with oral nimodipine 30 to 60 mg every 4 hours or IV nimodipine 0.5 to 2 mg/h if the oral regimen failed or images showed cerebral vasospasm. With oral nimodipine, headache did not recur in the nine patients without vasospasm. IV nimodipine was given in two patients with vasospasm, including one who developed ischemic stroke. Nimodipine may be effective for TCH. Vasospasm may warrant IV nimodipine.
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PMID:Nimodipine for treatment of primary thunderclap headache. 1511 86

Increasing evidence implicates endothelin in the pathophysiological development of cerebral vasospasm. This review summarizes background topics such as the structures and biosynthesis of endothelins, the types of endothelin and their receptors, as well as their biological effects. Basic science and clinical observations supportive of the role of endothelins in the spasm associated with stroke and subarachnoid hemorrhage are presented. Similar basic science and clinical observations are presented regarding the role of endothelins in impaired cerebral hemodynamics following traumatic brain injury, cryogenic cortical lesion injury and fluid percussion brain injury. The role of age in the contribution of endothelin to impaired cerebral hemodynamics following fluid percussion brain injury is discussed. Finally, potential mechanisms for endothelin contributions to vasospasm following fluid percussion brain injury such as impaired K+ channel function are described.
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PMID:Endothelins and the role of endothelin antagonists in the management of posttraumatic vasospasm. 1528 94

A large body of evidence suggests a substantial role of the endothelin (ET) system in the pathophysiology of a variety of disease states, mainly of the cardiovascular system. Recently bosentan, an ET receptor antagonist, has received approval by the Food and Drug Administration (FDA) for use in pulmonary artery hypertension. The ET system may also be involved in cerebrovascular disorders such as stroke and, most notably, development of cerebral vasospasm following subarachnoid hemorrhage. The pathophysiological mechanisms contributing to the development of a cerebral vasospasm after subarachnoid hemorrhage may be taken as a paradigm to explore mechanisms leading to secondary ischemic brain damages in a variety of insults such as stroke and trauma. The present review provides the evidence to evaluate ET receptor antagonists for potential prophylactic and therapeutic use in patients suffering from subarachnoid hemorrhage. The rationale to develop selective ETA receptor antagonists is given with respect to basic and applied studies. This may be useful to better define the desired profile of action of a given compound, and it may also help to design appropriate preclinical and clinical trials, most desirably in close cooperation with pharmaceutical companies and neurosurgical departments.
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PMID:Experimental approaches to evaluate endothelin-A receptor antagonists. 1531 6


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