摘要:

A long-term decline in death rates from cerebrovascular diseases in the United States accelerated in 1969, with a further increase in the rate of decline after 1972. This break in the pattern of the mortality curve for stroke was observed in all 4 major sex-color groups, and affected all age groups in which a significant number of stroke deaths occur. The decline for non-whites was relatively and absolutely greater than for the comparable white sex. If the 1960 rates had persisted in 1975, 87,600 more lives would have been lost to cerebrovascular diseases. Although there are no data documenting a declining prevalence of hypertension in the population, detection, treatment and control of hypertension have improved markedly over recent years. A concomitant decrease in the severity of epidemic respiratory infection may have contributed to the improvement in recorded death rates from stroke. Mortality from all major cardiovascular diseases has demonstrated a parallel downward trend. Continued emphasis on public health efforts to detect and treat hypertension and other known cardiovascular risk factors can be expected to result in further improvement in cardiovascular mortality.

ISSN:0039-2499    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

Carotid endarterectomy has become a widely used approach to the treatment of cerebrovascular disease. In spite of increasing experience, a significant and varied morbidity remains attached to the procedure. A poorly recognized complication is postoperative headache. In a series of 57 endarterectomies in 50 patients, 24 patients experienced postoperative headaches encompassing the entire spectrum of vascular headaches: nonspecific diffuse headaches, severe hemicranias, cluster headaches occurring early and delayed, chronic paroxysmal hemicranias, carotidynia, and Eagle's syndrome. Five patients had hemicranias, and all were homolateral to the endarterectomy. Therefore, we hypothesize that the spontaneously occurring hemicranias, the counterparts of postsurgical headache syndromes, also may be due to some overt or occult injury or disease of the carotid vessels or carotid sheaths in the region from the carotid bifurcation to the base of the skull.

ISSN:0039-2499    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

In 38 patients who underwent cerebrovascular evaluation followed by angiography the Doppler ultrasound scanning technique was found to be an excellent screening procedure for detecting marked stenosis (> 50%) or occlusion of the internal carotid artery (93% correlation). It is noninvasive, easily reproducible and can be performed by a qualified technician. The major problems are: the inability to detect ulcerated plaques without marked stenosis, the requirement for patient cooperation (lying still for periods of 15 minutes), and the fact that it assesses only the extracranial circulation. Screening with just the directional ophthalmic Doppler flow signal yielded a high percentage of false negatives (13%). The presence of a cervical bruit may indicate an underlying stenosis of the internal carotid artery, but may also be due to stenosis of the external carotid artery or other factors such as increased blood flow, vessel tortuosity, etc. (12% false positives). Absence of a cervical bruit does not exclude internal carotid artery disease (ulcerated nonstenotic plaque or occlusion).

ISSN:0039-2499    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

A new method utilizing computer subtraction allows 2 separate radionuclide angiograms to be performed during a single laboratory visit. Two separate intravenous injections of the radionuclide are given so that the patient's head can be imaged in 2 different projections. Background activity from the first injection is subtracted by the computer to allow good resolution of blood flow following the second injection. A static brain scan is performed after the second injection. Although single-view radionuclide angiography is widely used in the diagnostic evaluation of the brain, the addition of a second projection provides additional important diagnostic information. The views obtained, however, must be determined individually for each patient on the basis of the clinical history and neurologic signs. The selection of appropriate views, the diagnostic quality of the studies, and the practical clinical application of this technique are illustrated by 2 case reports.

ISSN:0039-2499    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

We measured cerebral oxygen extraction, cerebral blood flow (CBF), and cerebral metabolic rate (CMRO2) in comatose patients during the first 60 hours after resuscitation from cardiac arrest. Each patient was studied 2 or 3 times. CBF was determined by a modification of the Kety-Schmidt method using inhaled Xenon133. Over the study period jugular venous oxygen tension and saturation rose, while the oxygen content difference between arterial and jugular venous blood fell, indicating a progressive increase in the ratio of CBF to metabolism. CBF and CMRO2 measurements confirmed this. Between 2 and 6 hours after resuscitation both measurements were severely but proportionately depressed to less than 50% of normal. After 6 hours CBF was increased disproportionately to CMRO2 so that a relative hyperemia developed and persisted for the duration of the study. Although regional inhomogeneity of flow and regional ischemia cannot be ruled out, we have found no evidence for global cerebral ischemia between 2 and 60 hours post-resuscitation as an explanation for failure of recovery. In man following cardiac arrest restoration of levels of global cerebral blood flow, which can be considered adequate relative to the depressed metabolic state of the tissue, is achieved within 2 hours of resuscitation.

ISSN:0039-2499    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

The effect of anticoagulation on lesions caused by cerebral emboli of different types was studied in 57 dogs. The resultant arterial and parenchyma! lesions were assessed by pathologic and angiographic studies. Embolization with emboli that caused little or no inflammatory response in the artery (12 dogs) was not associated with hemorrhagic infarcts or with subdural or subarachnoid hemorrhage; furthermore, treatment with anticoagulants (9 dogs) did not change the character of the lesions. Embolization with emboli that caused arteritis, that is, bacterial contamination or presence of lead chromate in the embolus (21 dogs), was associated with hemorrhagic infarcts, focal subarachnoid hemorrhage, and increased incidence of acute subdural hemorrhage. Treatment with anticoagulants (16 dogs) was associated with a further increase in the incidence of subdural hemorrhage.

ISSN:0039-2499    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

We have investigated the effects of a reduced regional or a reduced body temperature, on pial arteriolar response to a variety of vasoactive stimuli. This has been done by studying the effects of these stimuli on groups of mice with different body temperatures, or with different temperatures of the artificial cerebrospinal fluid (CSF) irrigating the pial surface. Responses in mice with body temperatures of 30° or 22°C showed little or no difference from responses in mice with body temperatures of 37°. This was so whether the surface irrigant was maintained at 37° or at 23°. On the other hand, significant reductions in pial vascular responses were observed when mice with "CSF" temperatures of 22° were compared with those having "CSF" temperatures of 37°. The data suggest that regional cooling is more effective than cooling the body in reducing the responses of pial arterioles. The data also indicate that marked reductions in body temperature would have to occur before a detectable effect on pial vascular responses is produced, at least in mice anesthetized with urethane.

ISSN:0039-2499    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

A perspex model of a dog aortic trifurcation was machined to scale and perfused with steady flow from a constant pressure reservoir. The tail artery was plugged to produce a flow model of an intracranial saccular aneurysm. At all flow rates, no flow occurred beyond 2.5 tube diameters of the tail artery downstream from the mouth of the aneurysm. This was assumed to explain why large aneurysms thrombose. Measurements of velocity fluctuations were made with a hot film anemometer and recorded on tape. Frequency analysis showed that the peak frequency was a function of flow rate, and suggested that eddies were shed from the origin of the aneurysm. This was presumed to be an artifact due to sharp entrance produced by machining the perspex. The total energy at any one point in the aneurysm was independent of the size of the aneurysm but increased with flow rate. The maximum fluctuations were comparable in the center and in the sides of the aneurysm, but were less on the top and bottom of it (assuming the central plane was in the plane of the trifurcation). This difference presumably would be less if the aneurysm were spherical rather than cylindrical.

ISSN:0039-2499    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

Conscious rats and rats under nitrous oxide anesthesia were subjected to blood pressure elevations by injection of epinephrine, bicuculline and amphetamine. Mean arterial pressure was measured from a chronic indwelling cannula in the aorta in awake rats. The protein leakage in the brains was studied using Evans blue and 125IHSA. Conscious animals developed less blood-brain barrier dysfunction than anesthetized ones. The largest difference was obtained with amphetamine and the smallest with epinephrine. Possible explanations to the results are discussed.

ISSN:0039-2499    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

Compression ischemia of the central nenous system (CNS) in heparinized dogs caused areas of diminished cerebral blood flow measured by "C-antipyrine autoradiography. Intravenous infusion of indomethacin (1.5 or 4.0 mg/kg) approximately 1 hour before ischemia eliminated the circulatory defects. Prophylactic inhibition of prostaglandin synthetase may promote postischemic perfusion of the CNS by preventing vasoconstriction and by anti-hemostatic effects on blood.

ISSN:0039-2499    

出版商:OVID    

年代:1978

数据来源: OVID