ISSN:0039-2499    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Systemic hypertension (secondary to aortic coarctation) produces in monkeys, muitifocal brain lesions where capillaries show increased diameter, endothelial degeneration and deposition of collagen and other substances in the basement membrane. In one animal, capillary changes were detected as early as 8 weeks after induction of hypertension. Similar capillary alterations were demonstrated in brain samples of hypertensive humans obtained at autopsy. We suggest that the above abnormalities may be the result of successive episodes of regional ischemia and/or hyperperfusion. Validation of these observations requires careful evaluation of additional human and animal brains. Stroke, Vol 12, No 4, 1981

ISSN:0039-2499    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Air Injection into the carotid artery of adult mongotian gerbils caused, within 10 minutes, raultifocal brain lesions. The extracellular spaces were widened and neurons, oligodendrocytes and myelin sheaths remained unchanged. The "delayed" effects of air embolism (first seen after 3 h) were similar to those observed in gerbils after unilateral carotid ligation. The histologic alterations after 3 h consisted of astrocytic swelling and shrinkage/necrosis of neuronal soma. The observations reported here illustrate the temporal and spatial separations that exist between a) brain water retention, and b) intraparenchymal entry of horseradish peroxidase. Both alterations can be a consequence of either decreased blood flow or arterial air embolism. Edema and protein leakage in each situation may be initiated by different mechanisms. Stroke, Vol 12, No 4, 1981

ISSN:0039-2499    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Between January 1978 and December 1979 23 consecutive patients aged under 40 years with acute ischemic brain infarction were admitted to the department of neurology, Meilahti University Hospital in Helsinki. In 10 patients (43%) the onset of symptoms was preceded within 24 hours by ethanol intoxication, and all but one symptom occurred at weekends when most liquor is consumed in Finland. Ethanol intoxication preceding the stroke was 4 times as common in female and 5 times as common in male patients as ethanol intoxication in the general Finnish population of the same age and sex. The present results support those of our previous study and suggest that occasional ethanol intoxication increases the risk of ischemic brain infarction both in adolescents and young adults. Stroke, Vol 12, No 4, 1981

ISSN:0039-2499    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Non-invasive methods are described for estimating local cerebral blood flows (LCBF) and partition coefficients (Lλ) during inhalation of 35% stable xenon gas (Xea) in oxygen during CT scanning. After denitrogenatioD by 100% oxygen breathing, 35% Xe5is breathed for 7-8 minutes to minimize subanestbetic effects. Mean changes in brain Hounsfleld units extrapolated to 15 minutes were 7.7 units for white matter and S3 units for gray matter. They were measured from volumes 80 cubic mm (10 mm2area X 8 mm), or larger with an EMI 1010 scanner at 1 minute intervals. These data were used for computing LCBFs and Lλs. Irradiation measured at the center of brain slices was 1 rad per minute. To calculate Lλs about 6 exposures are necessary, thereafter, each 1 minute scan provides LCBF measurements for 2 adjacent 8 mm slices. ReproducibUity for LCBF was r = 0.85 (P< 0.001). Mean Lλs were 0.86 ± 0.08 for gray and 134 ± 0.10 for white matter. Normative mean flows (mls/100 g brain/min) were: basal ganglia = 79.6 ± 93, cortex = 82.3 ± 8.5, white matter = 29.2 ± 5.9, mldbrain tegmentum = 943 ± 14.8, cerebellar cortex = 80.1 ± 10.9, dorsal poos = 89.3 ± 4.7, brachium ponds = 35.0 ± 4.2. Subject finger exercises produced increases of LCBF in contralateral pre-central and post-central gyri. Eye closure decreased flow values limited to the visual system. Gray matter flow values diffusely decreased in non-REM sleep but increased above normal in REM sleep. Cerebral infarction and hemorrhage resulted hi zones of zero flow with borders having reduced Xs and low flows attributed to edema. Stroke, Vol 12, No 4, 1981

ISSN:0039-2499    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

A method for measuring regional cerebral circulation time (rCCT) between the hemispheres using intravenous pertechnetate and a multidetector system is presented. Interhemlspheric differences of rCCT Instead of absolute values were selected because of the variation of pertechnetate bolus dispersion due to changes In tbe systemic circulation and injection technique Inter- and intraindividually. Time activity curves over one minute were analyzed by a modified gamma function fitting method. The results are printed as a brain map which snows reference values and abnormal findings. Abnormal rCCT asymmetry was observed hi 10 out of 77 controls (13%) and 58 out of 65 patients with cerebral infarction (89%). Within 2 weeks after a stroke shorter circulation time values on the side of the lesion than on the contralateral side were found in 5 patients. In the severe infarction cases and in the acute stages of Infarction circulatory changes could be found In a great number of areas. In patients with manifest diabetes abnormal circulatory findings occurred in larger regions and hi a greater number of the patients than hi those without that disease. Although the luxury perfusion and diaschisis phenomena, as well as the influence of cross-over of the count rates between tbe hemispheres, reduce circulatory time differences, use of the present pertechnetate method allows detection of subtle regional circulatory changes in patients with brain infarction. Stroke, Vol 12, No 4, 1981

ISSN:0039-2499    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Cerebral atfaeroembolism, in which mainly lipid emboli are released from rupturing atheromatoas plaques, may occur without apparent effect, or result in cerebral ischemia and Infarction. The reasons behind these unpredictable consequences were sought in the interactions, in vitro and in an animal model, between the main lipid components of advanced plaques. Pure preparations of representative Upids were each harmless when embolized into the cerebral circulation. In contrast, combinations in proportions similar to those in advanced human plaques caused infarction, whether these were synthetic mixtures or extracts from plaques of the entire lipid fraction. The most important physical interaction between the lipids was aggregation of crystals by oils. Between cholesterol and the mainly liquid esters, this created in vitro a range of glutinous aggregates. Trigiyceride lowered the melting point of esters, increasing their oillness, and reduced the cohesiveness of aggregates in the face of operative mechanical forces through a fall in viscosity. Pftospholipid, acting principally as an emulsifying agent, promoted dispersion of the oQ, secondarily freeing die crystals from its aggregating effect. In the plaque, the balance of these factors will determine the size and number of particles likely to embolize, and, therefore, the clinical outcome should the plaque rupture. Stroke, Vol 12, No 4, 1981

ISSN:0039-2499    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

Tomogrephic images of cerebral blood flow (CBF) and oxygen extraction fraction (OEF) using theUO continuous inhalation technique, and positron emission tomography, were obtained from a patient with cerebral ischemia distal to an occluded left internal carotid artery. There was a focal mismatch between CBF and oxygen metabolism in the brain supplied by tbe middle cerebral artery where CBF was decreased and OEF increased ("misery-perfusion syndrome" as opposed to "luxury-perfusioa syndrome"). These abnormalities were most marked in tbe parieto-ocdpital watershed area. After left superficial temporal to middle cerebral artery anastomosis, the clinical attacks ceased and a repeat study did not demonstrate tbe prerious CBF and OEF abnormalities. This suggests that this pattern of abnormalities indicates potential liable tissue. The concept of "mlsery-perfuslon" may be of some importance In tbe patbophysiological mechanisms of hemodynamic cerebral ischemia and serve as a rational basis for rerascularization procedures. Stroke, Vol 12, No 4, 1981

ISSN:0039-2499    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

A stroke registry was established in Shibata City, Nilgata Prefecture, Japan (population 75,000) in 1976. WHO recommendations for criteria were followed. This paper reports stroke incidence for die initial 3 years of the registry: 1976 dirough 1978. All liring padents were examined clinically by a staff physician. Only patients with a diagnosis of first stroke were included in die study. Sensitivity of the referral system was estimated at 85 + %, comparable to that in American studies.Arerage annual incidence per 1,000 in residents ⩾20 years was 2.61 for all strokes (3.42 for males; 1.88 for females), 0.20 for subarachnoid hemorrhage, 0.61 for cerebral hemorrhage, 1.51 for cerebral infarction — rates similar to those reported 10-20 years previously for the United States.The male-female ratio, 2:1, reflected a high rate among males, low among females. Rates among Shibata males were higher than 1972 U.S. rates reported by die Epidemiologic Study Group; rates among Shibata females were lower than corresponding U.S. rates.Incidence of all strokes combined increased with age, die age reiadonship being strongest for cerebral infarction. No subarachnoid hemorrhage was observed in Shibata residents ⩾70 years of age. Stroke, Vol 12, No 4, 1981

ISSN:0039-2499    

出版商:OVID    

年代:1981

数据来源: OVID

摘要:

A population-based stroke incidence study was carried out in Melbourne, Australia, between March 1978 and September 1979. Age-sex specific incidence rates were calculated and shown to be similar to those reported from the United States. At 18 months after the onset of stroke 55% of patients were alire and the probability of surviral was shown to be related to the level of consciousness at time of maximum Impairment. Seasonal rariability of stroke incidence was demonstrated, as was an association between incidence rates and country of birth. Stroke, Vol 12, No4, 1981

ISSN:0039-2499    

出版商:OVID    

年代:1981

数据来源: OVID