ISSN:0039-2499    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Background and Purpose:The purpose of this study was to compare the effects of low‐to‐high doses of aspirin on platelet aggregability determined by different methods and on the metabolism of thromboxane A2and prostacyclin.Methods:We administered increasing doses (40, 320, and 1,280 mg/day) of aspirin to 19 poststroke patients and studied the differences in 1) the changes in platelet aggregability depending on the methods of evaluation and 2) the concentrations of prostaglandin metabolites in the blood and urine.Results:Aggregation of platelet‐rich plasma induced by a strong stimulus (10 &mgr;M ADP) was significantly reduced after 40 mg/day aspirin (p< 0.005), and this reduction was similar to that after higher aspirin doses. In contrast, aggregation of platelet‐rich plasma induced by weaker stimuli (1 and 5 &mgr;M ADP) decreased less significantly after 40 mg/day aspirin compared with that after higher aspirin doses. The serum thromboxane B2generated after ex vivo incubation was reduced significantly (by 85%) after 40 mg/day aspirin and decreased further after 320 mg/day (by 96%) and 1,280 mg/day (by > 99%) of aspirin. The urinary 11‐dehydro‐thromboxane B2concentration decreased less significantly after 40 mg/day aspirin (by 42%) compared with that after 320 mg/day (by 78%) and 1,280 mg/day (by 91%) aspirin doses. The urinary concentration of 2, 3‐dinor‐6‐keto‐prostaglandin f1&agr;did not decrease after 40 mg/day aspirin but decreased significantly after higher doses of aspirin.Conclusions:These findings suggest that different doses of aspirin may be necessary to prevent thrombogenesis induced by different triggers of different strengths and that 40 mg/day aspirin is able to inhibit a large proportion of maximum thromboxane A2release provoked acutely, with the prostaglandin I2synthesis being little affected; however, higher doses of aspirin are required to attain further inhibition. (Stroke1992;23:1400‐1403)

ISSN:0039-2499    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Background and Purpose:Delayed ischemic deficits contribute to the high morbidity and mortality rates associated with subarachnoid hemorrhage. We evaluated the potential usefulness of measuring coagulation and hemorheological variables and cardiolipin antibodies for prediction of delayed ischemic deficit after subarachnoid hemorrhage.Methods:Consecutive patients with subarachnoid hemorrhage were studied. Coagulation and hemorheological variables and cardiolipin antibodies were measured on admission, within 7 days of subarachnoid hemorrhage. A subset of patients was studied on admission and at two subsequent occasions.Results:Sixty‐nine patients were studied. Sixty‐one of these were without clinical manifestations of vasospasm at admission, and 16 developed delayed ischemic deficit during their hospitalization. None of the laboratory variables measured were significantly different between patients with or without later development of delayed ischemic deficit. Elevation of the fibrin fragment d‐dimer was found in the group of eight patients admitted with ischemic symptoms and in 49% (34 of 69) of all patients, but this was not associated with delayed ischemic deficit. Sixteen patients were studied on three occasions; this group showed a significant decrease in hematocrit, an increased white blood cell count, and no change in fibrinogen concentration. Fibrin d‐dimer levels rose significantly after surgery (from 5.01±0.69 to 5.53 ± 0.58 In‐ng/ml,p< 0.025) and after onset of delayed ischemic deficit (from 4.71 ± 0.64 to 5.84 ± 0.34 In‐ng/ml,p< 0.01).Conclusions:Hemostatic measurements, hemorheological variables, and cardiolipin immunoreactivity did not predict delayed ischemic deficit in this population. (Stroke1992;23:1404‐1409)

ISSN:0039-2499    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Background and Purpose:Stroke risk factors have been shown to change with time in several places; simultaneously, stroke incidence rates have increased in some and decreased in other places. In Göteborg, Sweden, cardiovascular epidemiological research has included stroke registration since 1971. From these data on stroke, incidence and fatality rates from a 17‐year period are given.Methods:During the period 1971‐1987 all cases of stroke occurring in people aged 15‐65 years in the city of Göteborg were uniformly recorded, with an estimated case detection rate of 90% or more.Results:Age‐adjusted incidence rates of first‐ever stroke by sex did not change during the period. Age‐specific rates and rates for individual types of stroke (subarachnoid hemorrhage, intracerebral hemorrhage, and cerebral infarction‐unspecified stroke combined) were also largely unchanged. A slight increase in the incidence rate of intracerebral hemorrhage may be due to better detection after computed tomography came into use in 1976. Stroke fatality rates declined through the whole period in both sexes and all age groups, markedly so for intracerebral hemorrhage and subarachnoid hemorrhage.Conclusions:This conforms with vital statistics for Göteborg and for Sweden of declining stroke mortality during the period. The decline in stroke fatality rates may be related to decreases in smoking habits and blood pressure together with an increase in the percentage of people on antihypertensive treatment among middle‐aged men, and to some extent even middle‐aged women, reported from the same population. Why stroke incidence rates did not decline concomitantly is unexplained. (Stroke1992;23:1410‐1415)

ISSN:0039-2499    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Background and Purpose:Unruptured intracranial aneurysms constitute a significant public health problem that has not been quantified. The purpose of this study is to document the magnitude of this problem in the United States.Methods:National Hospital Discharge Survey data from 1979, 1984, and 1989 served as the basis for calculating patient numbers and frequency distributions. Cost estimates included the direct costs of hospitalization and surgery for those who had surgery, disability and lost income from morbidity, and lost income from mortality.Results:The estimated lifetime cost (including hospitalization, surgery, morbidity, and mortality) for annual cases of patients hospitalized with unruptured intracranial aneurysms in the United States is $522,500,000 compared with $1,755,600,000 for patients with aneurysmal subarachnoid hemorrhage.Conclusions:These data underscore the need to better understand unruptured intracranial aneurysm as a risk factor for subarachnoid hemorrhage, to define other subarachnoid hemorrhage risk factors, and to optimize the management of patients with these conditions. (Stroke1992;23:1416‐1419)

ISSN:0039-2499    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Background and Purpose:Our purpose was to describe and further understand the determinants of the time of onset of parenchymatous intracerebral hemorrhage and subarachnoid hemorrhage in patients enrolled in the Stroke Data Bank.Methods:We analyzed the observed times of onset of intracerebral hemorrhage (n= 237 patients) and subarachnoid hemorrhage (n= 243 patients) compared with expected times of onset if the probability of onset was constant across all time intervals. We also analyzed the role of clinical features (if any) in explaining the findings.Results:For intracerebral hemorrhage, 52.5% of patients reported onset times between 0600 hours and 1400 hours, with peak onset between 1000 and 1200 hours (&khgr;2=62.94, df=11,p<0.001). Patients with subarachnoid hemorrhage were more likely to lack a history of hypertension compared with patients who had intracerebral hemorrhage (&khgr;2=23.3, df=1,p<0.001). Patients with subarachnoid hemorrhage were more likely to have more uniform onset time throughout the day (&khgr;2=12.92, df=7,p=0.074). However, subarachnoid hemorrhage patients with a history of hypertension were more likely to have peak onset times in mid‐to‐late morning compared with patients without such a history (&khgr;2=35.25, df=10,p<0.001). The nonuniformity of onset times for intracerebral hemorrhage persisted even if patients with unknown onset times were treated as though their onset times were randomly distributed between 0000 and 0800 hours. Seasonal periodicity and the relation between initial systolic or diastolic blood pressure and time of onset for either type of hemorrhage were not observed.Conclusions:Our data suggest that the time of onset for both intracerebral hemorrhage and subarachnoid hemorrhage patients with a history of hypertension is similar to the diurnal variation in blood pressure. (Stroke1992;23:1420‐1426)

ISSN:0039-2499    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Background and Purpose:Sleep apnea syndrome may lead to changes in cerebral hemodynamics due to altered alveolar ventilation. We investigated the dynamics of CO2‐and blood pressure‐regulated alterations of cerebral blood flow velocities during apneic episodes and evaluated CO2reactivity during different sleep stages.Methods:A computer‐assisted pulsed Doppler system (2 MHz) was used for continuous overnight recordings of middle cerebral artery flow patterns together with simultaneous polysomnography, continuous blood pressure recordings, and measurements of end‐expiratory CO2in six patients with sleep apnea syndrome.Results:Increases in mean flow velocity of 19‐219% and in blood pressure of 12.5‐83.1% could be observed during the apneic episodes, with maximum increases during rapid eye movement (REM) sleep. CO2reactivity was in the normal range (4.4±1.2%) in the waking state and was markedly increased during sleep stages 1 and 2 (p<0.005 compared with awake). The greatest increase was found during REM sleep, with a rise of up to three times the waking value (p<0.0001 compared with sleep stage 2).Conclusions:The changes of mean flow velocity could be interpreted as reactive adaptation processes because of CO2and blood pressure increases corresponding to apnea. The increased CO2reactivity during sleep may indicate a “hypersensitivity” of intracranial vascular CO2or pH receptors and a disturbance of central catecholaminergic and cholinergic systems. The pronounced velocity changes during apneic episodes and the concomitant alterations of vessel wall tension might lead to microangiopathies and macroangiopathies due to chronic strain on the brain vessels. (Stroke1992;23:1427‐1433)

ISSN:0039-2499    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Background and Purpose:Close relations between leukoaraiosis detected by computed tomography or magnetic resonance imaging and stroke, particularly lacunar infarction, have been reported. We studied whether leukoaraiosis is related to long‐term prognosis for patients with lacunar infarction.Methods:We examined monthly 215 patients with lacunar infarction after their first stroke. They comprised 95 patients with leukoaraiosis disclosed by computed tomography on admission (58 men and 37 women; mean age, 71.3±9.0 years) and 120 patients without leukoaraiosis (81 men and 39 women; mean age, 65.5±8.9 years). These patients had no previous history of either stroke or obvious dementia before their index stroke. We compared the prognosis with and without leukoaraiosis based on analysis of recurrent stroke, survival, and the prevalence of dementia and rate of dependence in activities of daily living.Results:Life table analysis revealed that the recurrent stroke rate was significantly higher in the patients with leukoaraiosis than in those without it (p=0.004). The prevalence of dementia and rate of dependence in activities of daily living both 1 month after the index stroke and at the end of the follow‐up period were significantly higher in the patients with leukoaraiosis (all parameters,p<0.001). Their survival rate was significantly lower than in those not suffering from leukoaraiosis (p=0.012). Significant differences in these comparisons were also observed after matching for age and sex.Conclusions:The presence of leukoaraiosis as identified by computed tomography indicates a poor prognosis for patients with lacunar infarction. (Stroke1992;23:1434‐1438)

ISSN:0039-2499    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Background and Purpose:Many patient monitoring techniques have been used for detecting cerebral hypoperfusion during carotid endarterectomy. We compared middle cerebral artery blood flow velocities with carotid artery stump pressures to evaluate the indications for common carotid artery cross‐clamp shunting and the probable hemodynamic causes of cerebrovascular complications.Methods:Blood flow velocities were monitored with transcranial Doppler ultrasound and carotid stump pressures were measured at the time of common carotid artery cross‐clamping during 97 carotid endarterectomy procedures. Stump pressures measured with the gauge zero reference at the common carotid artery level were correlated with the percentage change of velocities.Results:Middle cerebral artery blood flow velocities usually decreased upon common carotid artery cross‐clamping, depending on collateral availability and the autoregulation response. The best fit of the data was to an exponential function concave to the pressure axis, with velocity as a percentage of the pre‐cross‐clamp value reaching zero at 15 mm Hg stump pressure (r=0.85 andp<0.001).Conclusions:There is a less critical margin of error with percentage middle cerebral artery blood flow velocity decreases than with stump pressure measurements. This relation establishes changes in middle cerebral artery blood flow velocities as a reliable parameter for judging the effects of carotid cross‐clamping on cerebral blood flow and providing an excellent indicator as to the necessity for shunting. (Stroke1992;23:1439‐1445)

ISSN:0039-2499    

出版商:OVID    

年代:1992

数据来源: OVID

摘要:

Background and Purpose:Psychological and biological hypotheses have been proposed to explain anosognosia. We correlated the presence of anosognosia with the presence and severity of psychiatric disturbances, neglect, intellectual impairments, and computed tomographic evidence of lesion size, location, and measurements of brain atrophy.Methods:A series of 80 patients with acute stroke were assessed using a battery of psychiatric and neuropsychological tests and computed tomography.Results:There were five main findings. First, 27 (28%) of the 96 patients originally screened showed anosognosia. Second, patients with anosognosia had significantly higher frequencies of hemispatial neglect and related phenomena, as well as deficits in recognizing facial emotions and in receptive prosody. Third, depression was equally frequent among patients with and without anosognosia. Fourth, patients with anosognosia had a significantly higher frequency of right hemisphere lesions, primarily involving the temporoparietal junction, thalamus, and basal ganglia. Fifth, patients with anosognosia showed significantly more subcortical brain atrophy, primarily involving the frontal white matter and diencephalic areas.Conclusions:The present study demonstrates that anosognosia does not “protect” stroke patients from depressive feelings; rather, it represents arousal‐attentional disorders after lesions in specific areas of the right hemisphere in nonaphasic patients with preexisting subcortical atrophy. (Stroke1992;23:1446‐1453)

ISSN:0039-2499    

出版商:OVID    

年代:1992

数据来源: OVID