摘要:

We studied 1,273 patients with ischemic cerebral infarction who were entered into the Stroke Data Bank, a prospective, observational study involving four university hospitals and the Biometry and Field Studies Branch of the National Institute of Neurological Disorders and Stroke. Forty patients had noniatrogenic recurrent stroke within 30 days after the index cerebral infarction. Using life tables, the 30-day cumulative±SE risk of early recurrence for all infarctions was 3.3±0.4%. The risk of early recurrence was greatest for atherothrombotic infarction (7.9±2.2%, eight of 113 patients) and least for lacunar infarction (2.2±1.2%, eight of 337 patients). Both cardioembolic infarction (4.3±0.9%, 10 of 246 patients) and infarction of undetermined cause (3.0±0.5%, 14 of 508 patients) had intermediate risks. History of hypertension and diabetes mellitus, as well as diastolic hypertension and elevated blood sugar concentration at admission, were associated with early recurrence. Logistic regression analysis estimated the risk of early recurrence to be 8.56% in those with coexisting hypertension and a glucose concentration of 300 mg/dl versus 0.77% in the absence of these two abnormalities. Early recurrence was associated with longer median duration of initial hospital stay (27 vs. 14 days) and a higher 30-day case-fatality rate (20% vs. 7.4%). Increased weakness scores were associated with early recurrent stroke. Identification of the determinants of early recurrent stroke may lead to better secondary prevention and may help select high-risk patients for further study.

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Review of 2,859 autopsy reports disclosed lacunar infarctions in 169 patients (6%). Review of the charts of 167 of these patients revealed hypertension in 64%, diabetes in 34%, smoking in 46%, and no known risk factor for cerebrovascular disease in 18%. As many as 81% of the patients with lacunes were asymptomatic. Symptomatic lacunes presented most commonly as pure motor hemiparesis (31%), aphasia plus right hemiparesis (20%), or sensorimotor dysfunction (11%); none presented as pure sensory stroke. These results suggest that the spectrum of lacunar infarction is more heterogeneous than previously thought. Most lacunes are asymptomatic, and the majority of symptomatic patients do not present with “classical” lacunar syndromes.

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Factors associated with stroke and other cardiac embolic events in subjects with nonrheumatic atrial fibrillation were examined in a retrospective study of 91 patients from a teaching hospital clinic. There were 28 first strokes during 355 person-years of follow-up (7.9 per 100 person-years). Patients who had experienced one or more previous events were approximately 2.3 times more likely to have a subsequent event (hazard ratio 2.3, 95% confidence interval 1.5–3.4) than patients who had experienced no events. A univariate analysis of factors associated with a first stroke of any cause or other embolic event showed that age of >75 years (hazard ratio 2.5) and systolic blood pressure of >160 mm Hg (hazard ratio 6.4) were significant factors. After adjusting for the effect of age and systolic blood pressure, previous events still carried an increased risk for subsequent events. Subjects with nonrheumatic atrial fibrillation who have had one or more embolic events are at high risk of further emboli. They require special consideration when treatment is being planned.

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

While changes in blood velocity in the middle cerebral artery relative to rest were assessed by transcranial Doppler sonography, 70 volunteers with no sign of cerebrovascular disease performed two (left and right middle cerebral artery) series of six cognitive tasks. The tasks are assumed to be processed predominantly by either the left (verbal and mathematical tests performed aloud) or the right hemisphere (dot/distance estimation, spatial perception, and face recognition performed silently). All tasks were shown to increase middle cerebral artery blood flow velocity on both sides, by 1.6–10.6%. After an initial maximum at approximately 8 seconds, velocity decreased then increased again. A steady state was reached after approximately 24–42 seconds. The initial minimum during the following rest phase was reached some seconds later, followed by a slow increase to the reference rest steady state. A difference according to side could be determined only during the three right-hemispheric tasks (right>left, 2.5–2.9%). Lefthandedness/ambidexterity, familial sinistrality, and profession seemed to have no influence on the results. The middle cerebral artery blood flow velocity increase on both sides was higher in women than in men during the dot/distance estimation and was also higher bilaterally in older than in younger subjects during the dot/distance and the spatial perception tasks. Habituation in performing the tasks was an important factor associated with a decrease of blood flow velocity, especially in the right middle cerebral artery. The habituation more pronounced on the right side possibly reflects the role of the right hemisphere in attention and arousal. The absolute blood velocities at rest decreased bilaterally with age.

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

In 102 patients with angiographically proven occlusive carotid artery disease of 60–100% diameter reduction, Doppler ophthalmic artery pressure and blood flow direction were recorded by the recently developed ophthalmomanometry-Doppler technique. Among these 102 patients, 50 presented with complete carotid artery occlusions and 52 with carotid artery diameter stenoses of ⩽60%. Mean±SD Doppler ophthalmic artery pressure was 69 ±15 mm Hg ipsilateral to the occlusion and 86 ±18 mm Hg ipsilateral to a stenosis of the carotid artery (/> < 0.001). The mean±SD Doppler ophthalmic pressure index (ratio of the ophthalmic artery to systemic blood pressure) was lower ipsilateral to the occlusion (0.46 ±0.08) than ipsilateral to a carotid artery stenosis (0.54±0.08;/> < 0.001); in both, the index was clearly diminished compared with normal values (0.68 ±0.04;p< 0.001). It is concluded that the intracranial hemodynamic consequences in the patients with occlusion are on average more profound than in the patients with stenosis. In carotid artery occlusions, the mean±SD ipsilateral ophthalmic pressure index was 0.46 ±0.06 for antegrade and 0.46 ±0.09 for retrograde ophthalmic artery blood flow. In carotid artery stenoses, the mean±SD ipsilateral ophthalmic pressure index was 0.55 ±0.07 for antegrade and 0.48 ±0.06 for retrograde ophthalmic artery blood flow (/? < 0.01). These results indicate that in carotid stenoses the collateral capacity of the ophthalmic artery is insufficient compared with intracranial collaterals, while in carotid occlusions the blood flow direction in the ophthalmic artery does not predict intracranial hemodynamic compensation.

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

We studied 33 consecutive patients with computed tomographic findings of decreased density in the periventricular white matter (leukoaraiosis). Computed tomograms in five (aged 56–75 years) of the 33 demonstrated intracerebral hematoma. The hemorrhages were situated in the thalamic area in four and in the parietotemporal area in one patient. These five patients were hypertensive and had signs characteristic of parenchymal hemorrhage. Three of the five patients had progressive dementia prior to the ictus, and two of the three also had a history of single or multiple strokes. There was no significant difference in the clinical findings of hematoma patients with or without leukoaraiosis.

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Severe chronic cerebral vasospasm was produced in dog basilar arteries by two injections, 2 days apart, of autologous blood into the cisterna magna of 25 dogs. Treatment with ibuprofen (n= 8) or high-dose methylprednisolone (n= 8) after the first injection of blood prevented or reduced angiographic vasospasm. Cerebrospinal fluid concentrations of prostaglandin E2, prostaglandin F2α, 6-ketoprostaglandin F1α(a metabolite of prostacyclin), and thromboxane B2(a metabolite of thromboxane A2) were measured in both treated and untreated (n= 7) dogs. In untreated dogs, the level of prostaglandin E2increased 94-fold by Day 8 after the first injection of blood and was strongly and positively correlated with the degree of angiographic vasospasm. Treatment with ibuprofen and high-dose methylprednisolone prevented or significantly reduced this increase in prostaglandin E2concentration. Smaller increases in cerebrospinal fluid concentrations of thromboxane B2and 6-ketoprostaglandin F1αoccurred after experimental subarachnoid hemorrhage; the magnitude of these increases was also reduced by ibuprofen or high-dose methylprednisolone treatment. In contrast, prostaglandin F2αlevels were not significantly altered during the study. These data show that enhanced prostaglandin E2synthesis occurs during experimental subarachnoid hemorrhage, and the by-products generated in its synthesis may play a role in the pathogenesis of cerebral vasospasm.

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Recent studies show that acute and chronic hyperglycemia cause a diffuse decrease in regional cerebral blood flow and that chronic hyperglycemia decreases the brain L-glucose space. Since these changes can be caused by a decreased density of perfused brain capillaries, we used 30 adult male Wistar rats to study the effect of acute and chronic hyperglycemia on 1) the brain intravascular space using radioiodinated albumin, 2) the anatomic density of brain capillaries using alkaline phosphatase histochemistry, and 3) the fraction of brain capillaries that are perfused using the fluorescein isothiocyanate-dextran method. Our results indicate that acute and chronic hyperglycemia do not affect the brain intravascular space nor the anatomic density of brain capillaries. Also, there were no differences in capillary recruitment among normoglycemic, acutely hyperglycemic, and chronically hyperglycemic rats. These results suggest that the shrinkage of the brain L-glucose space in chronic hyperglycemia is more likely due to changes in the blood-brain barrier permeability to L-glucose.

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Ischemia due to middle cerebral artery occlusion was studied in 29 rats from 1 to 24 hours after occlusion using magnetic resonance imaging. Images were made before and after the injection of a superparamagnetic iron oxide compound, AMI-25. Subtraction images demonstrated the region of perfusion deficit as early as 1 hour after occlusion, earlier than conventional T2-weighted images. The area of altered perfusion detected by this technique (subtraction imaging after AMI-25 administration) correlated with that demonstrated by iodoantipyrine autoradiography. Since this magnetic resonance technique can be used to serially estimate the location and size of the ischemic area, the technique can be an important adjunct to metabolic studies of focal ischemia using magnetic resonance spectroscopy. The technique may have clinical applications as well.

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

We describe a new focal ischemia model consisting of unilateral middle cerebral artery occlusion with a silicone rubber cylinder attached to a nylon surgical thread inserted through the internal carotid artery in rats. Recirculation was accomplished by pulling the thread out of the artery. We evaluated the reliability of this model and studied the influence of reperfusion of the brain by measuring regional cerebral blood flow in 30 rats and by using conventional neuropathologic methods after different periods of occlusion in 48 rats. The anterior neocortex and the lateral part of the caudate putamen, which were supplied by the occluded middle cerebral artery, were the regions most frequently damaged. After 1 hour of occlusion in five rats, in the cortex supplied by the occluded artery mean±SD blood flow was 0.19±0.08 ml/g/min (approximately 15% of that in the corresponding region of five sham-operated control rats), and mild scattered ischemic cell change was observed. Three (n= 5) or six (n= 5) hours of occlusion reduced blood flow more severely and caused severe ischemic cell changes in the cortex supplied by the occluded artery in proportion to the duration of ischemia. Characteristically, in five rats subjected to 3 hours of occlusion followed by 3 hours of recirculation, blood flow was restored and spongy edematous change was observed in the cortex supplied by the recirculated artery. This change resulted in hypoperfusion of the neighboring cortical region surrounding the recirculated area. Our model should be useful in various investigations of the influence of reperfusion on focal ischemic brain injury.

ISSN:0039-2499    

出版商:OVID    

年代:1989

数据来源: OVID