ISSN:0039-2499    

出版商:OVID    

年代:1985

数据来源: OVID

ISSN:0039-2499    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The association between non-rheumatic atrial fibrillation (AF) and stroke has been studied in 402 patients consecutively admitted to a stroke unit. Brain infarction patients with sinus rhythm (n= 196) and non-rheumatic AF (n= 92) were further compared. Some findings supported an embolic origin of the stroke: half of the deceased AF patients (n= 24) at autopsy either had left atrial thrombosis or arterial embolism compared to none of the ten with sinus rhythm. Patients with AF also had a higher mortality and more severe brain lesions, findings compatible with a sudden occlusion of blood flow. However, these differences might also be explained by an atherothrombotic occlusion with impaired autoregulation in the ischaemic region in conjunction with heart failure, which was more common in the AF patients. Other findings supporting an atherothrombotic mechanism were: the prevalence of AF was higher (19-29%) in all kinds of stroke, including haemorrhage, than in age-matched controls (3-9%). Also patients with previous AF and no present embolic source resembled the whole AF group and differed from patients with sinus rhythm. Thus embolism is a plausible cause of stroke in many AF patients, whereas an atherothrombotic origin is more likely in others. Characteristics identifying the mechanism in an individual case were not found.

ISSN:0039-2499    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

During a 20-month study period there were 373 strokes in a geographically defined population (235/100,000/year). When age and sex were adjusted to the mean population of Finland in 1979, the annual incidence of stroke was 270/100,000 persons. The distribution of incident cases by diagnostic category was as follows: cerebral infarction 80%, ICH 9%, SAH 8% and NOS 3%. Case fatality of stroke within one year was 37%. The recurrence rate was 6% during the first year after any stroke.

ISSN:0039-2499    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

This study examines the effect of fibrinogen and consequent blood viscosity reduction on cerebral blood flow and cellular injury following severe cerebral ischemia for 30 minutes in 78 Wistar rats. In half of these rats 10 to 15 cc's of blood was removed and replaced with a mixture of 5% albumin and autologous red blood cells maintaining a constant hematocrit but resulting in a 30% decrease in fibrinogen and corresponding reduction in viscosity. Fibrinogen reduction resulted in a slight increase in baseline CBF and the elimination of post-ischemic hyperemia at 24 hours. Both study and control animals showed a similar decrease in CBF at 30 minutes and 2 hours. There was no significant difference in the severity of ischemic cellular change between the fibrinogen reduction group and controls, although there was a significant inverse relationship between the amount of viscosity change and severity of cellular injury within the treatment group. Fibrinogen reduction alone cannot significantly ameliorate ischemic injury in this model. Viscosity reduction therapy should include reduction of hematocrit and alteration of red cell deformability.

ISSN:0039-2499    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

A series of 38 patients with angiographically proven cerebral venous thrombosis (CVT) affecting dural sinuses is reported. This study shows that CVT is not rare, that the clinical diagnosis is extremely difficult because of the variable modes of onset and groupings of symptoms, that most CT findings are non specific and that angiography remains the best diagnostic tool. Only 4 patients died, which suggests a more benign outcome than classically described. None of the 23 heparin treated patients died, which indicates that anticoagulants were not harmful in this series.

ISSN:0039-2499    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

In 36 patients with angiographically proven middle cerebral artery (MCA) stenosis, local cerebral hemodynamics were studied employing angiography,133Xe inhalation regional cerebral blood flow (rCBF) measurements and CT scans. They had transient ischemic attacks in 8 and completed stroke in 28. The patients with less than 50% stenosis (n= 16) had no hemodynamic abnormality in angiographical and rCBF examinations. The infarction in this group was small and located in the basal ganglia area. The patients with 50 to 74% stenosis (n= 9) often revealed a delayed filling of MCA branches in the angiography, however, they showed no significant rCBF reduction. The infarction in this group was also small and located in the basal ganglia area. The patients with 75 to 99% stenosis (n= 11) exhibited significant flow depression both in angiographical and rCBF examinations. Three of them had large cerebral infarction in the watershed zone or the cerebral cortex. The results of the present study suggest that the hemodynamic effect of MCA stenosis begins to manifest at 50% in grade and becomes apparent at 75%. The danger of hemodynamic crisis as well as the risk of large cerebral infarction may increase when MCA stenosis exceeds 75% in grade.

ISSN:0039-2499    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The high incidence of mitral valve prolapse (MVP) in patients with ischemic attacks is puzzling when compared with the very low incidence of cerebrovascular attacks observed in individuals known to have MVP. Our aim was to determine if it is possible to identify a patient subset with MVP at the highest risk of embolization on the basis of 2D-echocardiographic findings.We compared the echocardiographic picture of a group of 39 patients with MVP and cerebral ischemic attacks (29 TIAs, 10 strokes) in the carotid territory, without any pathological lesions at angiography, with that of a control group of 111 patients with MVP without neurological complications. The two groups were not different for age or sex.Patients with MVP and neurological complications showed a higher prevalence of aortic valve prolapse (62% vs 34%,p< 0.01), of an association between valvular diffuse thickening and aortic valve prolapse (54% vs23%,p= 0.001), and of multiple valve prolapse with valvular diffuse thickening (26% vs7%,p< 0.01) than those of the control group.This study suggests that in young people cerebral ischemic events could be related to the presence of a combined valve prolapse and to an echocardiographic picture of valve diffuse thickening. These data suggest that in this selected group with multiple valve prolapse and valvar diffuse thickening prophylaxis against embolic events by pharmacological preventive measures should be considered.

ISSN:0039-2499    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

Various studies indicate that after a latent interval, a progressive focal deterioration of microvascular perfusion can develop in zones of acute damage to the central nervous system (CNS). In order to obtain reliable information concerning the possibility of platelet participation in this phenomenon, platelet deposition was investigated by means of111Indium-labeled platelets, and compared with local cerebral blood flow (CBF) and cortical sensory evoked response (CSER). Studies were performed with a model of focal ischemia in which small volumes of air were injected selectively into one internal carotid artery of dogs anesthetized with alpha chloralose throughout the experiment. The ischemic period was followed by a 10-min, 60-min or 4-hr recovery period. The main result was a prominent and diffuse accumulation of platelets in zones of low CBF in dogs subjected to 4 hr recovery.

ISSN:0039-2499    

出版商:OVID    

年代:1985

数据来源: OVID

摘要:

The effect of indomethacin on rCBF was studied in cats anesthetized with Nembutal either under resting conditions or with temporary middle cerebral artery (MCA) occlusion. RCBF was measured by the microsphere method. In control animals (n= 3), indomethacin (4 mg/kg, i.v.) significantly reduced rCBF by about 25% in both cortex (from 44 ± 6 to 32 ± 3 ml/100 g/min,p< 0.001) and white matter (from 36 ± 4 to 26 ± 2 ml/100 g/min,p< 0.001). After MCA occlusion rCBF was markedly decreased in the sylvian region ipsilateral to occlusion (ischemic core) (from 38 ± 4 to 14 ± 2 ml/100 g/min in cortex, 4 animals). Although pretreatment with indomethacin (4 mg/kg) (4 animals) 30 min prior to occhision did not alter rCBF during ischemia, a marked enhancement of reactive hyperemia was observed in the ischemic core immediately upon reperfusion following 2 h occlusion (54 ± 1 1 untreated vs 95 ± 13 treated,p< 0.05). In the delayed postischemic period, namely 2 h after recirculation, rCBF still remained to be higher in the animals treated with indomethacin (40 ± 6 untreated vs 96 ± 9 treated,p< 0.001). Such an effect of indomethacin for ameliorating postischemic blood flow in both the immediate and delayed period was less prominent in the adjacent area (penumbra) ipsilateral to occlusion. In the contralateral hemisphere, indomethacin caused slight reduction in rCBF during ischemia. An altered relationship between the actions of PGI2and TXA2has been proposed to occur at the blood-endothelium interface during reperfusion after ischemia in which a disproportionate synthesis of TXA2might be suppressed by indomethacin, whereas indomethacin dominantly suppresses PGI2synthesis under normal conditions.

ISSN:0039-2499    

出版商:OVID    

年代:1985

数据来源: OVID