摘要:

Platelet scintigraphy (PSC) with indium—Ill labelled platelets has been confirmed as an adequate method for the detection of intracardiac thrombi in patients with heart disease. We performed PSC of the heart and the neck vessels in 27 stroke patients with suspected cardiac embolism and as control on 10 patients with atherosclerotic lesions of the carotid arteries without evidence of heart disease. The carotid PSC was positive in 6 of 10 patients with carotid disease, and twice in the 27 with suspected cardiac embolism. In these 27 the PSC of the heart indicated pathological conditions 13 times. Pathological platelet accumulations could be visualized in 3 cases in the atrial space, in 9 cases in the region of the left ventricle, and once at the aortic valve. Scintigraphy was negative in all 10 patients with atherosclerosis of the neck vessels. The two—dimensional ecbocardiography revealed pathological findings in 8 of the 13 patients with positive heart PSC (3 with intraventricular thrombi, 3 with valvular disease, 2 with decreased ventricular contractility) and was normal in the 10 control patients. Open—heart surgery was performed in 2 patients with pathological PSC and revealed an intracardiac thrombus. Three of 4 patients with positive atrial PSC showed mitral or aortic valve disease. These results suggest that PSC can provide a valuable method for detecting cardiac thrombi in stroke patients. (Stroke1987;18:63–67)

ISSN:0039-2499    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

A total of 1,377 patients with symptomatic obstructive cerebrovascular disease (most commonly, internal carotid artery occlusion) entered a trial in which they were randomized to either medical or surgical (extracranial—intracranial bypass) therapy. All but 8 had hemoglobin estimations performed at entry. The patients were followed for an average of 55.8 months. In the medical group, the 325 patients with high normal hemoglobin concentration (15 g/1 or more) suffered no more ischemic strokes than the 382 patients with lower values (< 15 g/1). Those strokes that did occur were no more severe in the high than the low hemoglobin group. Hemoglobin concentration did not emerge as a prognostic factor in those patients treated surgically (n = 662). This prospective study counters the hypothesis that high normal hemoglobin concentration is associated with poor outcome in patients with symptomatic obstructive disease of the carotid and cerebral arteries. (Stroke1987;18:68–71)

ISSN:0039-2499    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Changes in multimodality evoked potentials (MEP's), consisting of somatosensory evoked potentials (SEP's), visual evoked potentials (VEP's), and auditory evoked brainstem responses (AEBR's), were studied in 36 patients with hypertensive putaminal hemorrhage to ascertain the relation among areas and distribution of brain dysfunction, the size of hemorrhage on computerized tomographic scan, and the clinical outcome. Among MEP's, SEP's were most significantly involved in all patients. Abnormalities in VEP's and AEBR's remained mild or moderate when the hemorrhage did not extend to the diencephalon. If SEP's were normal or mildly abnormal, they improved early after the ictus. These patients did well clinically. If SEP's were absent, the patients had poor outcome even when the hemorrhage was small and located outside the internal capsule. In contrast, deterioration or persistence of MEP's indicated secondary insult to the brain and poor patient outcome. Early and serial MEP studies are useful in evaluating primary and secondary brain dysfunction and in predicting patient outcome in hypertensive putaminal hemorrhage. (Stroke1987; 18:72–76)

ISSN:0039-2499    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

The middle cerebral artery was occluded in 18 cats to evaluate the physiological consequences of cerebral blood flow reductions on the somatosensory evoked potential, spontaneous neuronal activity, and oxygen availability in the ipsilateral and contralateral hemispheres. In the ipsilateral ectosylvian gyrus high—grade ischemia was produced as blood flow in the gray matter was reduced from 52.1 ± 8.6 '± SE) to 13.3 ± 9.0 ml/100 g/min and in the white matter from 33.8 ± 5.6 to 6.1 ± 6.4 ml/100 g/min. This significant reduction (p < 0.05) was associated with abolition of the cortical component of the somatosensory evoked potentials. In all animals occlusion resulted in a predictable extended latency change and a variable amplitude response of the cortical component of the contralaterally recorded somatosensory evoked potentials. In 5 animals, oxygen availability was measured and spontaneous neuronal activity in the contralateral hemisphere was recorded. Volume expansion and hemodilution with either dextran or saline infusions elevated cerebral blood flow in the contralateral gray matter significantly (p < 0.05) compared with the control and clip values. Ipsilateral spontaneous activity stopped within 4–12 minutes of occlusion, while contralateral spike activity persisted at rates at least equal to those recorded immediately following occlusion. (Stroke1987;18:77–84)

ISSN:0039-2499    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

This study examined the role of denervation supersensitivity in the development of cerebral vasospasm.Adrenergic denervation of cat basilar artery was accomplished by resection of the superior cervical ganglia or by injection of 6‐hydroxydopamine into the cisterna magna. In vivo dose—response characteristics were determined for normal and for denervated arteries, and no significant differences were found between topical applications of serotonin, norepinephrine, epinephrine, fresh blood, or incubated blood. In addition, analysis of cat blood incubatedin vitrorevealed that the levels of serotonin, norepinephrine, and epinephrine diminished over time, whereas levels of hemoglobin and methemoglobin increased up to Day 14. The results of this study indicate that adrenergic denervation is not the cause of cerebral vasospasm and that, whatever the mechanism, hemoglobin is far more likely to play a role than are the other agents. (Stroke1987;18:85–91)

ISSN:0039-2499    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

The effects of changing intraluminal pressure on contractions induced by 70 mM potassium (K+) and 10−7, 10−6, and 10−5M serotonin (5‐HT) were studiedin vitroin bovine middle cerebral arteries. Changes in vessel outside diameter in whole—mounted cylindrical sections of artery were detected with a photoelectric infrared device. High K+or 5‐HT (10−5M) induced contractions peaked at 25 mm Hg and were significantly correlated with increasing intraluminal pressure between 25 and 175 mm Hg. Contractions induced with lower concentrations of 5‐HT (10−6, 10−7M), norepinephrine, and histamine peaked at 75 mm Hg but were not significantly correlated with rising pressure. Phentolamine (2 × 10−6M) added to the extraluminal bath had negligible influence on pressure's ability to affect K+and 5‐HT—induced contractions differently. Reducing bath temperature to 27°C reduced the K+ response at each pressure, but similar temperature changes had little affect on the 5‐HT—induced contractions. The K+ response became less sensitive to increasing pressure at low temperatures. Nifedipine (10−7M) almost totally eliminated K+‐induced contractions, while significantly reducing the responses to all concentrations of 5‐HT. The 5‐HT responses appeared more sensitive to increasing intraluminal pressure in the presence of nifedipine. Maximum Ca++‐induced contractions in the presence of 10−5M 5‐HT and high K+occurred at 25 mm Hg, while Ca++‐induced contractions and Ca++‐induced contractions in the presence of 10−75‐HT or K+plus 5‐HT were maximum at 75 mm Hg. This study reveals significant differences in the ability of increasing intraluminal pressure to affect a electromechanical—induced contraction compared to a pharmacological—induced contraction. The results suggest that pressure has selective effects on the mechanisms that control cytoplasmic calcium in the smooth muscle cell. (Stroke1987;18:92–100)

ISSN:0039-2499    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Using directional continuous—wave Doppler sonography of the vertebral arteries, we have investigated 1,540 patients during the past 5 years. On the basis of unilateral and bilateral retrograde brachial angiograms in the same patients (a total of 1,989 angiograms) we have developed sonographic criteria for demonstrating a significant increase in the peripheral resistance of both distal vertebral arteries and/or the basilar artery. All 11 cases of basilar artery stenosis of at least 60% reduction in lumen diameter (as shown by angiography) exhibited an approximately 40% or higher reduction in the sum of the modified Pourcelot indices of both vertebral arteries with respect to age—matched controls. All 3 stenoses of less than 60% reduction in lumen diameter were not detected by sonography. Even a good collateral circulation through rete mirabile anastomoses did not normalize the modified Pourcelot indices. One case of a persistent primitive trigeminal artery with thin—calibered vertebral arteries was also detected by sonography. The high percent of patients with one hypoplastic vertebral artery in the group with basilar artery stenoses indicates an increased risk for atherosclerosis of the basilar and/or distal vertebral artery in these patients. All 14 angiographically verified occlusions of the basilar artery were detected by sonographic criteria independent of the occlusion localization. Thus, we believe that directional continuous—wave Doppler sonography is a reliable technique for detecting basilar artery stenoses of at least 60% reduction in lumen diameter and basilar artery occlusions. (Stroke 1987;18:101–107)

ISSN:0039-2499    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

Dopamine release into the extracellular space was measured within vivoelectrochemical detection in the ipsilateral and contralateral striata in Mongolian gerbils that suffered a stroke after acute unilateral carotid artery ligations. A sevenfold increase in the dopamine signal occurred within 15 minutes of carotid ligation in the ischemic side, while the unlesioned side had no significant change. Increased extracellular levels of dopamine persisted throughout the 3‐hour recording period. Pretreatment with a—methyl—p—tyrosine 6 hours prior to recording significantly attenuated the signal increase. This study is the first direct demonstration of the marked, continuous dopamine release that occurs during acute cerebral ischemia. (Stroke 1987;18:108–110)

ISSN:0039-2499    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

The postischemic production of PGE2, PGD2, 6—keto—PGFla, and TXB2in brain tissue was studied in Mongolian gerbils using tissue extraction as well as a new ex vivo method. This new method permits the study of prostaglandin synthesis in slices from discrete areas of the brain (cortex, hippocampus, striatum, hypothalamus). Gerbils were sacrificed at 0, 5, and 30 minutes, and 4 and 24 hours after a 15‐minute occlusion of both carotid arteries. Apart from 6—keto—PGFla, tissue prostaglandins determined by the extraction method were significantly increased 3 and 30 minutes after reperfusion. The most pronounced changes found by theex vivomethod were increased productions of PGD2immediately after reperfusion (285% in cortex, 215% in hypothalamus) and PGE2(350% in hippocampus, 320% in striatum) 4 hours after reperfusion. At 24 hours after reperfusion PGE2and PGD2synthesis were significantly decreased by 23–70% of the values obtained from sham—operated controls. Thromboxane increased slightly in all areas after recirculation and subsequently decreased to values below the control level in striatum. The results obtained by ex vivo incubation of tissue slices demonstrate that ischemia and subsequent recirculation cause site‐, time‐, and PG—specific changes of tissue eicosanoid production. (Stroke 1987;18:111–119)

ISSN:0039-2499    

出版商:OVID    

年代:1987

数据来源: OVID

摘要:

The effects of ergotamine and dihydroergotamine on cerebral blood now was investigated 4 hours after i.v. injection as these drugs might be of importance for migraine treatment. Eight normal male volunteers (not suffering from migraine) received 0.5 mg ergotamine and 1 mg dihydroergotamine i.v. Cerebral blood flow was measured by the xenon‐133 inhalation method and single—photon—emission computerized tomography before and after intravenous acetazolamide administration (1 g). Cerebral blood flow was measured before and 4 hours after ergotamine and dihydroergotamine administration. Strain—gauge measurements of toe—arm systolic gradients were used to monitor the effect of the drug on leg arteries. Mean hemispheric and regional cerebral blood flow was unchanged after either drug (mean ± SEM, ml/100 g/min): for ergotamine, 57 ± 3 before and 57 ± 3 at 4 hours; for dihydroergotamine, 54 ± 2 before and 55 ± 2 at 4 hours. The acetazolamide response was unchanged as well. Only ergotamine decreased the toe—arm systolic gradient significantly (22 mm Hg at maximum after 240 minutes; p < 0.02). Thus, our study did not support the belief that ergot alkaloids should be withheld from patients during attacks of classic migraine, but this has to be investigated further. The discrepancy in the peripheral effects of ergotamine and dihydroergotamine might also be of clinical Importance. (Stroke1987;18:120–123)

ISSN:0039-2499    

出版商:OVID    

年代:1987

数据来源: OVID