摘要:

In a randomized pilot study we compared the efficacy of temporary anticoagulation with intravenous heparin sodium to the efficacy of aspirin in preventing cerebral infarction in hospitalized patients with recent (< 7 days) transient ischemic attacks (TIAs). Fifty-five patients (33 men, 22 women) aged 36–81 (mean 62.7) years met entry criteria and agreed to participate. Symptoms prompting hospitalization were referable to the carotid distribution in 43 patients (34 hemispheric, nine retinal); 12 patients had vertebrobasilar distribution TIAs. Twenty-seven patients received heparin and 28 received aspirin. Patients were treated until surgery or until long-term medical therapy was instituted, 3–9 (mean 5.5) days in the heparin group and 3–15 (mean 5.8) days in the aspirin group. Recurrent TIAs occurred in eight patients given heparin and in seven treated with aspirin. Infarction occurred in one patient in the heparin group and in four patients in the aspirin group (three brain, one retinal infarction). Initial symptoms in these five patients were referable to the carotid distribution in two and to the vertebrobasilar distribution in three. All patients but the one with a retinal infarction had recurrent TIAs prior to stroke. Our pilot study suggests that hospitalized patients with recent TIAs are at high risk for recurrent TIAs (15 of 55, 27%) and brain infarction (five of 55, 9%) and that patients with recent vertebrobasilar distribution TIAs have a marginally significantly higher risk (odds ratio 6.83, 95% confidence interval 0.65–88.66) of infarction than patients with recent carotid distribution TIAs.

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

We investigated the relation of plasma lipids to the risk for ischemic stroke by comparing clinical and biochemical characteristics of survivors of cortical (n= 48) and lacunar (n= 36) brain infarction. By analysis of variance, no differences were observed in the concentrations of total cholesterol, triglycerides, low density lipoprotein cholesterol, very low density lipoprotein cholesterol, or apoproteins Al and B. Patients with lacunar infarction, however, had higher concentrations of high density lipoprotein (HDL)-cholesterol than patients with cortical stroke. This HDL-cholesterol difference was due primarily to a strikingly low HDL-cholesterol content in white patients with cortical stroke. These data suggest that previously demonstrated differences in HDL-cholesterol concentrations between patients with ischemic stroke and control subjects without stroke may apply to patients with cortical but not lacunar infarction. Separation of cerebral infarction into subtypes based on mechanism may help clarify lipidrelated risk factors in cerebrovascular disease.

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

We measured cerebrovascular reactivity to carbon dioxide in the cerebral cortex and the subcortical white matter of 12 healthy adult volunteers (four young subjects aged 21–24, four middle-aged subjects aged 34–40, and four elderly subjects aged 62–85 years). Blood flow was computed from the concentration history of xenon-133 in the volume of interest measured with an ultrapure germanium detector array. End-tidal PacO2ranged from 35.4 to 42.6 mm Hg. The mean±SD baseline blood flows hi the cerebral cortex were 60±7, 51 ±9, and 33±4 ml/100 cm3/min in the young, the middle-aged, and the elderly subjects, respectively; the corresponding subcortical white matter baseline blood flows were 21±1, 22±3, and 16±5 ml/100 cm3/min. Mean±SD cerebrovascular reactivities to carbon dioxide in the cerebral cortex were 2.03±0.58, 1.36±0.41, and 0.72±0.19 ml/100 cm3/min/mm Hg PacO2for the young, the middle-aged, and the elderly subjects, respectively; the corresponding reactivities in the subcortical white matter were 0.69±0.11, 0.59±0.17, and 0.36±0.41 ml/100 cm3/min/mm Hg PacO2. Blood flow and cerebrovascular reactivity in the cerebral cortex of the young subjects were significantly higher than those for white matter and significantly higher than those in the elderly subjects (p< 0.001). Age vs. blood flow (for the cortex) and age vs. cerebrovascular reactivity (for both cortical gray and subcortical white matter) also showed significant linear correlation (p< 0.05). However, the age-related changes hi white matter blood flow and cerebrovascular reactivity were slow, and the differences among the age groups were not statistically significant.

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

We investigated 15 patients with one or more transient ischemic attacks (TIAs) hi the internal carotid artery territory within the month following the most recent TIA. Cerebral blood flow (CBF) was measured by single-photon emission computed tomography, using intravenous xenon-133 before and after injection of 1 g acetazolamide. Six patients had severe carotid stenosis or occlusion; the other nine patients had no significant carotid lesions. Twenty age-matched volunteers free of neurologic symptoms or history were used as controls. Mean CBF in the sylvian region was not significantly different between patients and controls. Seven patients exhibited a focal hypoperfusion at rest in the symptomatic hemisphere, and their hypoperfused areas were hyporeactive after administration of acetazolamide. Seven other patients exhibited hyporeactive areas after acetazolamide administration while their CBF tomograms at rest were normal. Thus, CBF abnormalities were detected in 14 of the 15 patients. Our findings suggest that CBF measured early after acetazolamide administration could be useful to confirm the clinical diagnosis of TIA. In the nine patients with no significant lesion of the internal carotid artery, the areas of hypoperfusion were small and were probably related to the focal ischemic event. In the six patients with severe lesions of the internal carotid artery, abnormalities were of variable size and intensity but were often large and pronounced. The discrepancy between these two subgroups of patients could be ascribed to the hemodynamic influence of the internal carotid artery lesions. Moreover, our findings may provide some insight into the pathophysiology of TIAs.

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

We studied 40 patients with stroke of potential cardioembolic origin by cardiac ultrafast computed tomography and two-dimensional echocardiography. Cardiac ultrafast computed tomography was more sensitive (positive in eight of 14 instances) than two-dimensional echocardiography (positive in two of 14 instances) for the detection of intracardiac thrombus, which was found in 13 patients. Mitral anular calcification was diagnosed more often by two-dimensional echocardiography (four of five instances) than by cardiac ultrafast computed tomography (one of five instances); this implies a high incidence of false-positives for the former. Cardiac ultrafast computed tomography showed that one half of the patients (21 of 40) had coronary artery calcification, indicating a high incidence of coronary atheroma in this patient population. Future studies comparing brain and cardiac pathology with the findings of cardiac ultrafast computed tomography and patient prognosis are needed to define the significance and utility of this technique in patients with stroke.

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The time of onset of ischemic stroke was determined for 1,167 of 1,273 patients during the collection of data by four academic hospital centers between June 30,1983, and June 30, 1986. More strokes occurred in awake patients from 10:00 AM to noon than during any other 2-hour interval. The incidence of stroke onset declined steadily during the remainder of the day and early evening. The onset of stroke is least likely to occur in the late evening, before midnight.

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

We retrospectively evaluated 66 patients younger than 40 years of age who presented with acute nonhemorrhagic cerebral infarction (n= 63) or transient ischemic attacks (n= 3) to determine the possible etiology and long-term outcome at a mean follow-up interval of 3 years after initial presentation. A probable cause for the stroke was identified in 24 patients (36%); this group included one woman with a history of recurrent spontaneous abortions and a positive test for the presence of the lupus anticoagulant. We performed detailed hemostatic investigations at follow-up in 38 (90%) of the remaining 42 patients in whom the cause of the stroke was unknown or uncertain; results of the basic hemostatic screening tests (including that for fibrinogen) were uniformly normal. All 38 patients demonstrated a normal fibrinolytic response as measured by tissue plasminogen activator release to a standard venous occlusion stress test; concentration of the inhibitor of tissue plasminogen activator was not increased. No abnormalities in the concentrations of the inhibitory proteins C or S or antithrombin m were identified, and none of the 38 patients had evidence of a lupus anticoagulant. Neurologic recovery was complete or the residual disability mild in 46 of 59 (78%) patients. Overall prognosis was excellent and independent of whether a precipitating factor for the stroke could be identified.

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

We evaluated 80 stroke patients to examine the contributions of caregiver anxiety, self-care ability, age, time since onset, marital and residential status, and need for health care services on personal adjustment as reported by caregivers. Mean age of the patients was 65.4 years, and the average time from stroke onset to evaluation was 415 days. Multiple regression analyses indicated that a significant amount of variance in patient adjustment was accounted for by caregiver anxiety (μ2 = 0.28,p< 0.05) and patient self-care ability (R2 = 0.13,p< 0.05). Compared with community norms, stroke patients were reported to be more depressed, confused, and anxious and they demonstrated fewer household management skills. Stroke patients were not different from a normative sample on measures of interpersonal involvement or social activity. Caregivers had high levels of anxiety compared with norms. Our results may aid in developing methods for identifying stroke patients and caregivers at risk for suboptimal adjustment.

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Free radicals have been shown to play an important role in ischemia-reperfusion injury in several organ systems; however, the role of free radicals in central nervous system ischemia has been less well studied. Many potential free radical-generating systems exist. The primary products of these reactions, superoxide and hydrogen peroxide, may combine to produce hydroxyl radicals. Of the many potential sources of free radical generation, the enzyme xanthine oxidase has been shown to be important in ischemia in noncerebral tissue. We investigated the effect of the hydroxyl radical scavenger dimethylthiourea and the xanthine oxidase inhibitor allopurinol on infarct volume in a model of continuous partial ischemia. Male Sprague-Dawley rats were treated with dimethylthiourea or allopurinol before middle cerebral artery occlusion. Infarct volume was measured by triphenyltetrazolium chloride staining of brains removed 3 or 24 hours after occlusion. Stroke volume was reduced by 30% after dimethylthiourea treatment and by 32–35% after allopurinol treatment. At 24 hours after stroke, cortical tissue was more effectively protected than caudate tissue with both agents. Pretreatment with dimethylthiourea and allopurinol also significantly reduced cerebral edema formation and improved blood-brain barrier function as measured by fluorescein uptake. Our results imply that hydroxyl radicals are important in tissue injury secondary to partial cerebral ischemia and that xanthine oxidase may be the primary source of these radicals.

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Male Fischer-344 rats aged 6,12, or 24 months were subjected to four-vessel occlusion cerebral ischemia to assess age-dependent ischemic vulnerability of cholinergic and GABAergic neurons based on choline acetyltransferase (EC 2.3.1.6) and gJutamic acid decarboxylase (EC 4.1.1.15) activities. Activities of both enzymes were similar (/?>0.05) in 6- (n= 5) and 12- (n= 5) month-old rats. Mean±SEM choline acetyltransferase activities in the cortex, hippocampus, striatum, and cerebellum of 6-month-old controls were 75±5, 123±9, 415±9, and 50±4 μmol acetylcholine/hr/mg protein, respectively, and were 20–30% lower (/? < 0.05) in all brain regions except the cerebellum in 24-month-old controls. Choline acetyltransferase activity was unaffected by ischemia in 6- and 12-month-old rats but was reduced by 30–60% in 24- month-old rats. Mean±SEM glutamic acid decarboxylase activities in the cortex, hippocampus, striatum, and cerebellum of 6-month-old controls were 98±8, 86±7,144±13, and 125±9 μmol y-aminobutyric acid/hr/mg protein, respectively, and 25–35% lower in all regions of 24- month-old controls. After 30 minutes of ischemia and 5 days of recovery, glutamic acid decarboxylase activities were reduced (/? < 0.05) in all brain regions and age groups. However, its activity was decreased (p< 0.05 compared with age-matched controls) by 55% in the cortex and 79% in the hippocampus of 24-month-old rats compared with 30% and 45% in younger rats. Our results show that both choline acetyltransferase and glutamic acid decarboxylase activities were more vulnerable to ischemia in 24-month-old than in 6- and 12-month-old rats.

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID