ISSN:0039-2499    

出版商:OVID    

年代:1986

数据来源: OVID

ISSN:0039-2499    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Sixty‐five consecutive patients with recent unequivocal TIA (33) or stroke (32), but nondiagnostic arteriograms, had two‐dimensional echocardiograms (2DE) and electrocardiograms (ECG) to determine the incidence of cardiac abnormalities which could cause embolic stroke. Abnormalities were classified according to increasing probability of causing an embolic event: non‐specific, possible emboligenic abnormality (PEA) or definite emboligenic abnormality (EA).Although 2DE was abnormal in 33 patients (51%), and ECG in 38 (59%), many abnormalities were nonspecific. Only four patients (6%) had EA on ECG and two (3%) on 2DE. Since one patient had EA on both tests, 2DE identified only one patient (mitral valve prolapse) not already identified by ECG. All patients with EA had a prior history of cardiac disease. PEA was present on ECG in 11 patients (17%), and on 2DE in 25 (38%). There was no correlation between age, CT results, or neurologic symptoms commonly associated with embolic stroke and the presence of EA or PEA on ECG or 2DE.Although TIA and stroke patients with negative arteriograms have a high incidence of abnormalities on ECG and 2DE, the percentage of patients with EA is low, and cardiac history and ECG identify most patients. 2DE provides little additional information.

ISSN:0039-2499    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

This third paper from the Persantine® Aspirin Trial examines the data to identify risk factors for stroke in persons with a history of carotid territory transient ischemic attacks (TIAs) Fifteen centers in the United States and Canada participated, and 890 subjects were admitted and randomly allocated to either aspirin plus placebo or aspirin plus dipyridamole (Persantine).Persons with the following characteristics were in greater jeopardy for stroke, retinal infarction, or death: older age, history of heart disease, history of peripheral vascular disease, and persisting neurologic deficit from a recent event. Elevated diastolic blood pressure, diabetes, use of estrogen, and smoking were not found to be risk factors. Elevated systolic blood pressure was a risk factor primarily in subjects with a history of heart disease. Estrogen use may actually have had a protective effect for womenThis cannot be considered as a report of the natural history of TIA patients; it does identify risk factors in a specific cohort of subjects under treatment.

ISSN:0039-2499    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

The relationship between alcohol consumption and stroke mortality in 1975 in 46 prefectures of Japan was investigated. This was done by adjusting salt intake and several socio‐economic factors, i.e., the annual per capita income, the number of persons who received public aid, the number of tatamis (a Japanese traditional floor unit) per household, the unemployment rate, and the unmarried or divorce rate, using a stepwise multiple regression analysis. As dependent variables, the sex‐specific and age‐adjusted mortality for the middle‐aged (35–59 years) and for all ages due to stroke were used. For men, alcohol consumption was significantly related to age‐adjusted stroke mortalities for the middle‐aged and for all ages independent of salt intake and several socio‐economic factors. Alcohol consumption was more strongly related to age‐adjusted stroke mortality for the middle‐aged than for all ages. For women alcohol was weakly correlated with the stroke mortality of the middle‐aged. Salt intake was significantly correlated with stroke mortality for women but not for men. Furthermore, the male: female ratios of the age‐adjusted stroke mortality for the middle aged and for all ages were analyzed as well, because alcohol is mostly consumed by men in Japan, and it was expected that the sex ratios would be well correlated to alcohol consumption. The results were as expected. Therefore, it was suggested that the regional difference in stroke mortality in Japan may be explained in part by that of alcohol consumption.

ISSN:0039-2499    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Effects of intravenous infusion of dopamine on local cortical blood flow (CBF) and somatosensory evoked potentials (SEP) was evaluated using canine cerebral ischemia, which was produced by middle cerebral artery occlusion. CBF was monitored with a H2clearance method and SEP. Pt to N) peak to peak amplitude (V1) was recorded by stimulating the sciatic nerve on the contralateral side.CBF and SEP recovered at doses of 5 and 10γ, despite almost no increase of systemic arterial pressure. CBF and SEP were restored at doses of dopamine of 20 and 30γ, with an increase of mean systemic arterial pressure 5 to 15 mm Hg and similar results were obtained at doses of 25γ. Recovery of SEP was slight at extremely high doses of dopamine (65γ), despite a definite increase of mean systemic arterial pressure (MSAP) and CBF.

ISSN:0039-2499    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

The effects of hypoxic hypoxia on cerebral hemodynamics and somatosensory evoked potential (SEP) were studied in 10 pentobarbital anestheteized dogs. Cerebral blood flow (CBF) was measured using the venous outflow technique and cerebral oxygen consumption (CMRO2) was calculated from the arterio‐cerebro‐venous oxygen difference times CBF. SEP was evaluated by percutaneous stimulation of an upper extremity nerve and was recorded over the contralateral somatosensory cortex. The latencies of the initial negative wave (Nl), second positive wave (P2) and the amplitude of the primary complex (P1N1) were measured. Animals were breathed sequentially with oxygen concentrations of 21,10, 6, 5, and 4.5% for five minutes each. Animals were returned to room air breathing when the amplitude of the SEP decreased to < 20% of control and were observed for 30 minutes following reoxygenation. Severe hypoxia (4.5% O2) increased CBF to 200% of control, decreased CMRO2to 45% of control, decreased amplitude and increased latency of SEP. Following reoxygenation, as CMRO2increased toward control, latency of SEP decreased and amplitude increased and CBF returned to baseline within 30 min. During hypoxia and reoxygenation, the latencies of Nl and P2and the amplitude of P1N1 were correlated with CMR02in individual animals. We conclude that changes in SEP amplitude and latency reflect changes in CMRO2despite high CBF during rapidly progressive hypoxic hypoxia and following reoxygenation.

ISSN:0039-2499    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Acute focal ischemia was created in 10 cats by unilateral retro‐orbital middle cerebral artery (MCA) occlusion. Regional cerebral blood flow (CBF) was determined utilizing the hydrogen clearance technique from electrode recordings within the gray matter and white matter of the ectosylvian gyrus of both hemispheres. The somatosensory evoked potential (SSEP) was obtained during contralateral median nerve stimulation. When the MCA was clipped the white and gray matter blood flows in the ipsilateral ectosylvian gyrus were reduced to 14.8 ± 19.6% and 19.3 ± 23.7% of control, and the cortical component of the SSEP was abolished. In the contralateral hemisphere an average increase of 3.5% above the control latency and a 10% mean depression in the amplitude of the cortical component of the SSEP were observed following occlusion. CBF in the contralateral hemisphere was unaffected by the MCA clip. Infusion of saline or dextran to lower the hematocrit by approximately 45% did not significantly improve blood flow or restore the SSEP in the hemisphere ipsilateral to the MCA clip. However, significant increases in the contralateral hemisphere gray matter CBF occurred following hemodilution while the latency of the cortical component of the SSEP in this same hemisphere was significantly extended. Elevations in gray and white matter blood flows were achieved in the experimental hemisphere of 3 of 10 cats suggesting a wide range of variation in the collateral circulation.

ISSN:0039-2499    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

There is still considerable controversy regarding the influence of blood viscosity upon CBF. We have measured CBF with microspheres in 23 cats. Autoregulation was disturbed in the left caudate nucleus by microsurgical occlusion of the left middle cerebral artery. Induced hypertension or hypotension was used and i.v. mannitol (1 g/kg) administered. In all cats blood viscosity decreased an average of 16% at 15 minutes and, in 16 cats, increased 10% at 75 minutes post‐mannitol. CBF in the right caudate was 79 ± 6 ml/lOOg/min, in the left 38 ± 6 (p < 0.001). Only minor changes of CBF occurred in areas with presumed normal autoregulation, including the right caudate, in conjunction with pressure or viscosity changes. In the left caudate CBF decreased 21% with hypotension and 18% with higher viscosity, more than on the right (p < 0.01 and p < 0.2, respectively). CBF increased in the left caudate 56% with hypertension and 47% with lower viscosity, again much more than on the right (p< 0.001 and p < 0.01, respectively). In the other area which is (nearly) exclusively supplied by the middle cerebral artery of the cat, i.e., the ectosylvian cortex, results were similar to those in the caudate nucleus. These results show that viscosity changes must result in compensatory readjustments of vessel diameter, but that these adjustments do not occur where autoregulation to pressure changes is known to be defective. The adjustments to viscosity changes might be called blood viscosity autoregulation of CBF. We hypothesize that pressure autoregulation and blood viscosity autoregulation share the same mechanism.

ISSN:0039-2499    

出版商:OVID    

年代:1986

数据来源: OVID

摘要:

Acute onset hypesthetic‐ataxic‐hemiparesis is described in two hypertensive patients. Computed tomography (CT) showed an area of increased attenuation consistent with blood in contralateral thalamus. The pathophysiologic implications of the cerebellar and pyramidal system in thalamic hemorrhage is discussed.

ISSN:0039-2499    

出版商:OVID    

年代:1986

数据来源: OVID