摘要:

Cerebral hemispheric blood flow and metabolism were measured before and after therapy with intracarotid infusion of combined PBZ and PPL in IS patients with recent cerebral infarction. HBF was unaltered despite decrease in cerebral perfusion pressure. Cerebral hemispheric oxygen consumption and carbon dioxide production decreased while cerebral hemispheric lactate production increased. Biphasic cerebral uptake of tyrosine was observed during and immediately after PBZ and PPL infusion. CSF HVA increased, indicating altered DA turnover. CSF SHIAA levels also increased, suggesting altered SHT turnover after PBZ and PPL. Release of cyclic AMP from ischemic brain into cerebral venous blood seen in the steady state was abolished after therapy. Cerebral hemodynamic studies suggest a functional balance between monoaminergic neurogenic influences in the control of cerebral circulation. Imbalance of such controlling factors in ischemic brain may lead to paradoxical vascular responses to induced hypertension and hypotension. PBZ and PPL enhance such responses perhaps by increasing central neurotransmitter turnover and release. Further shift toward cerebral anaerobic metabolism may occur in ischemic brain following the use of phenoxybenzamine and propranolol. Worsening of neurological deficit occurred in four cases. Combined therapy with PBZ and PPL does not appear beneficial in the therapy of patients with recent stroke.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Previous surveys of stroke populations have offered only cursory information on language disturbance, and, conversely, few surveys of aphasic populations have dealt exclusively with stroke or with acute phenomena. This paper describes aphasia in 850 acute stroke patients consecutively registered by the Harlem Regional Stroke Program, of whom 177 (21%) were aphasic; of these, nine were of Broca's type, 24 were of Wernicke's type, 14 were anomic, ten were conduction, seven were of "isolation" type, and 107 were "mixed." An unexpected finding was a significant overrepresentation of men among the nonfluent aphasics. During the following four to 12 weeks, 12% of fluent aphasics died, and 12% remained moderately or severely impaired; among survivors, aphasia improved in 74%, and in 44% it cleared completely. During the same period, 32% of nonfluent aphasics died, and 34% remained moderately or severely impaired; among survivors, aphasia improved in 52%, and in only 13% did it clear completely. In both fluent and nonfluent groups, hemiparesis and/or visual field cut were associated with poor prognosis.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Longitudinal stretch of the rabbit basilar artery produces local injury followed by prolonged circular constriction. After stretching and rapid release in vitro localized constrictions promptly occurred. This could be prevented by prior treatment with cyanide or calcium-free solution. Once produced, constrictions persisted for more than 72 hours. Previously induced constriction was not reversed by treatment for two hours with cyanide or by removing calcium. Histological observation indicated that constricted areas were associated with a discrete circumferential rupture of the internal elastic lamina and disruption and thinning of the underlying media. Specific catecholamine fluorescence at the adventitio-medial junction was unchanged in constricted areas. The relationship between smooth muscle cell length and resting tension of artery segments with and without constrictions was compared. Segments with constrictions had a shorter muscle length for any given resting tension, which confirms that constriction was not due to passive collapse of the vessel wall. These findings suggest that injury of cerebrovascular smooth muscle may result in essentially irreversible vasoconstriction. Such a mechanism could contribute to the pathogenesis of prolonged cerebral vasospasm after SAH or traumatic injury to the cerebrum.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The effect of stimulation of fastigial nucleus (FN) on cerebral blood flow (CBF) was examined in anesthetized, paralyzed monkeys. CBF was measured with a flow transducer chronically implanted on the left common carotid artery. The left external carotid artery and its branches were ligated. Electrical stimulation of the fastigial nucleus produced rapid (within two seconds) increases in arterial pressure (AP) and heart rate. Mean carotid blood flow (MCBF) rose 77% (% 40% SEM) above control and followed the increases in mean arterial pressure (MAP). Calculated cerebrovascular resistance decreased immediately by 27% (% 14% SEM) below control. The increases in MCBF were not caused by a passively responding cerebrovascular bed (CVB) resulting from the stimulation or trauma to the vessels. Cerebral metabolism was not altered during stimulation as determined from the arteriovenous oxygen content difference. CBF autoregulation was still present with stimulation of the fastigial nucleus. The autoregulatory curve was shifted to a higher flow level. During the initial MAP changes in sympathectomized animals, MCBF increased to a greater extent than in the innervated animals, suggesting the presence of two neurogenic vasodilatory systems. It appears that electrical stimulation of the fastigial nucleus inhibits sympathetic tone and increases parasympathetic activity to the CVB, resulting in vasodilation and an increase in MCBF.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

This study was undertaken to establish the incidence and mortality for various types of cerebrovascular disease in the population of Tartu. All medical records for this population were reviewed for the period 1970 through 1973, and those with a diagnosis of brain infarction, transient ischemic attacks, cerebral hemorrhage or subarachnoid hemorrhage were identified. Only the first stroke was considered when determining incidence. A total of 786 cases were included in the study. Without cases of transient ischemic attacks, the number was 667 (e.g., cases of stroke). Cerebral infarction accounted for 80% of all strokes, cerebral hemorrhage for 13.5% and subarachnoid hemorrhage for 6.5%. The incidence rate for stroke was higher for men than for women and significantly increased in each older age group. The rate for all persons was 184 per 100,000 population per year. The incidence of transient ischemic attacks was 33 per 100,000 population per year. The mortality rate for stroke for this population was 98/100,000 per year. The data on incidence of stroke and its types, its dependence on age and sex, and mortality rate are close to the corresponding data reported from other countries.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The cerebrovascular response to hypercapnia and hyperventilation was studied in normal and jaundiced baboons by the intracarotid133Xe injection technique. The baboons with bile duct ligation were found to have decreased CBF at all levels of Paco2. This difference between normal and jaundiced baboons was 13% at normocapnia rising to 33% with hypercapnia and 37% with hypocapnia. The CBF values all were increased toward normal by use of an alpha-adrenoreceptor blockade (phentolamine). It is suggested that the obstructive jaundice potentiated an inherent vasoconstrictor alpha-adrenergic mechanism to oppose the effects of CO;. Also, alteration of the Paco2may have produced its effects on the cerebral vessels by altering this adrenergic mechanism.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

An understanding of the cerebral circulation is so fundamental to comprehension of the pathogenesis of stroke that cerebral blood flow and metabolism merit review in this series of reports. The authors recognize that the research described here is very technical in nature and may appear to have little practical application to clinical medicine. Nevertheless, these matters are basic to the development of precise methods for the measurement of regional cerebral blood flow in man which could be used to monitor the therapy of stroke with greater success than is possible at present.

ISSN:0039-2499    

出版商:OVID    

年代:1976

数据来源: OVID