Experimental augmentation of cerebral blood flow by intermittent aortic occlusion

1972 ◽  
Vol 36 (6) ◽  
pp. 700-713 ◽  
Author(s):  
Frederick A. Simeone ◽  
John P. Laurent ◽  
Peter J. Trepper ◽  
Daniel J. Brown ◽  
John Cotter
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Cardiovascular Response ◽  
Good Health ◽  
Aortic Occlusion ◽  
Regional Cerebral Blood ◽  
Descending Aorta ◽  
Content Type ◽  
The Common

✓ Intermittent occlusion of the descending aorta just below the origin of the brachiocephalic vessels by a preformed balloon passed via the femoral artery is capable of significantly increasing the pressure and flow in the common carotid artery. Regional cerebral blood flow determination by the krypton-85 washout technique measured maximum increases of over 40% of the controls, which could easily be achieved and maintained. This technique apparently takes advantage of the finite delay in autoregulatory response to the increased arterial pressure before the onset of maximal autoregulation. Dogs were “pumped” in this way for up to 18 hours and survived in good health. Principal problems with this technique were the development of cerebral edema in the presence of diffuse established cerebral anoxia, and a shock-like cardiovascular response if the intermittent aortic occlusion was discontinued too abruptly. The clinical application of this technique to cerebral ischemia secondary to postoperative vasospasm may not require the extremes of hyperperfusion used in these experiments.

Compartmental abnormalities of regional cerebral blood flow in children with head trauma

1972 ◽  
Vol 36 (4) ◽  
pp. 463-470 ◽  
Author(s):  
Samuel S. Kasoff ◽  
Lawrence H. Zingesser ◽  
Kenneth Shulman
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Gray Matter ◽  
Regional Cerebral Blood Flow ◽  
Head Injuries ◽  
Relative Weight ◽  
Compartmental Analysis ◽  
Regional Cerebral Blood ◽  
Content Type ◽  
Pediatric Age Group

✓ Regional cerebral blood flow (CBFr) and compartmental analysis in a series of children with closed head injuries have demonstrated abnormalities of both rate and distribution of blood flow. The most frequent derangement was a triphasic flow pattern overlying one or more regions of traumatized brain. The rate of flow in this third compartment is two to five times the rate of normal gray matter flow; while the relative weight of the compartment varies between 3.5% and 15%. The pathophysiology of this third, rapid compartment of flow is discussed, and the argument put forth that such flow does not represent hyperperfusion but rather an ischemia of the gray matter because such blood flow is not available to the tissue for nutrition. If this is so, it may well be a cause of permanent sequelae in the pediatric age group.

Regional cerebral blood flow and metabolism in reversible ischemia due to vasospasm

1985 ◽  
Vol 62 (4) ◽  
pp. 539-546 ◽  
Author(s):  
William J. Powers ◽  
Robert L. Grubb ◽  
Roy P. Baker ◽  
Mark A. Mintun ◽  
Marcus E. Raichle
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Emission Tomography ◽  
Neurological Deficits ◽  
Regional Cerebral Blood ◽  
Content Type ◽  
Cerebral Metabolic Rate ◽  
Positron Emission ◽  
Reversible Ischemia

✓ Regional cerebral blood flow (rCBF) and regional cerebral metabolic rate of oxygen (rCMRO2) were measured by positron emission tomography (PET) in four patients with subarachnoid hemorrhage and hemiparesis due to cerebral vasospasm. With resolution of the vasospasm, two patients recovered and two remained hemiparetic. Contralateral to the hemiparesis, rCBF was slightly higher in the two patients who eventually recovered (15.0 and 16.2 ml/100 gm/min) than in the two who remained hemiparetic (12.0 and 11.7 ml/100 gm/min). The rCMRO2 measurements showed similar differences, with values of 1.34 and 2.60 ml/100 gm/min in the patients who recovered, and 0.72 and 1.66 ml/100 gm/min in those who did not. These preliminary findings indicate that with PET studies it may be possible to prospectively differentiate patients with neurological deficits due to reversible ischemia from patients with irreversible infarction.

Regional cerebral blood flow studies in subarachnoid hemorrhage

1972 ◽  
Vol 37 (1) ◽  
pp. 36-44 ◽  
Author(s):  
M. Peter Heilbrun ◽  
Jes Olesen ◽  
Niels A. Lassen
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Subarachnoid Hemorrhage ◽  
Regional Cerebral Blood Flow ◽  
Surgical Intervention ◽  
Focal Ischemia ◽  
Regional Cerebral Blood ◽  
Content Type ◽  
Clinical Grading ◽  
Fine Print

✓ Regional cerebral blood flow (rCBF) studies using the intra-arterial 133xenon method were performed on 10 patients with subarachnoid hemorrhage. Both preoperative and postoperative studies showed evidence of decreased flow in the entire hemisphere studied, and, in addition, evidence of focal ischemia, focal hyperemia, focal vasoparalysis, and often global impairment of autoregulation. The degree of flow abnormalities correlated well with the clinical grading of the neurological deficit. It is suggested that analysis of the state of autoregulation might be useful in determining the time for surgical intervention and that rCBF studies are important in defining the effects of drugs used to counteract the ischemic effects of spasm.

Regional cerebral blood flow in the acute stage of experimentally induced subarachnoid hemorrhage

1983 ◽  
Vol 58 (2) ◽  
pp. 210-216 ◽  
Author(s):  
Felix Umansky ◽  
Thalia Kaspi ◽  
Mordechai N. Shalit
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Subarachnoid Hemorrhage ◽  
Regional Cerebral Blood Flow ◽  
Internal Capsule ◽  
Acute Stage ◽  
Regional Cerebral Blood ◽  
Content Type ◽  
Steep Decline ◽  
Triphasic Pattern

✓ Subarachnoid hemorrhage (SAH) was induced in 13 adult mongrel cats by a slow injection of fresh autogenous blood into the cisterna magna. Serial determinations of regional cerebral blood flow (rCBF) in the cortex and deep-seated areas (internal capsule, thalamus, and caudate nucleus) were made during the following 2 hours, while intracranial pressure (ICP) was maintained at normal values. A decrease in rCBF was observed in all the areas examined. This reduction followed a characteristic triphasic pattern with an initial steep decline immediately after the SAH. The clinical implications of these findings are discussed.

Beagle pup model of brain injury: regional cerebral blood flow and cerebral prostaglandins

1987 ◽  
Vol 67 (2) ◽  
pp. 278-283 ◽  
Author(s):  
Laura R. Ment ◽  
William B. Stewart ◽  
Charles C. Duncan ◽  
Bruce R. Pitt ◽  
Judith Cole
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Brain Injury ◽  
White Matter ◽  
Regional Cerebral Blood Flow ◽  
Ventilatory Support ◽  
Periventricular White Matter ◽  
Regional Cerebral Blood ◽  
Content Type ◽  
Carbon 14

✓ Asphyxia is the most common cause of severe brain injury in very young children, and frequently results in lesions of the periventricular white matter in addition to other neuropathological changes. This study examines the effects of asphyxia on regional cerebral blood flow (rCBF) and the role of prostaglandins (PG's) in its control in the newborn beagle pup. Pups were anesthetized, tracheotomized, paralyzed, artificially ventilated, and randomly assigned to two groups: asphyxial insult produced by discontinuing ventilatory support, and no insult. Experiments for carbon-14-iodoantipyrine autoradiographic determination of rCBF and regional cerebral PG determination were performed on separate groups of pups. These studies demonstrated a significant increase in cortical gray PGE2 levels at a time when rCBF was significantly impaired in response to severe asphyxial insult. No such increase was noted in the periventricular white matter zones.

Regional cerebral blood flow, sensory evoked potentials, and intracranial pressure in dogs with MCA occlusion by embolization or trapping

1983 ◽  
Vol 58 (4) ◽  
pp. 500-507 ◽  
Author(s):  
Yoshikazu Okada ◽  
Takeshi Shima ◽  
Mitsuo Yamamoto ◽  
Tohru Uozumi
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Intracranial Pressure ◽  
Evoked Potentials ◽  
Regional Cerebral Blood Flow ◽  
Regional Cerebral Blood ◽  
Content Type ◽  
Sensory Evoked Potentials ◽  
Sensory Evoked ◽  
Fine Print

✓ Regional cerebral blood flow (rCBF), sensory evoked potentials (SEP), and intracranial pressure (ICP) were investigated in dogs with focal cerebral ischemia produced by a silicone cylinder embolus in the middle cerebral artery (MCA) trunk as compared to that produced by trapping the same vessel. These variables were measured at intervals of 1 hour for a period of 6 hours after MCA occlusion. In the embolized animals, rCBF decreased most extensively at the basal ganglia, from a control level of 53.9 ± 3.9 (mean ± SE) to 21.5 ± 2.7 ml/100 gm/min at the 6th hour. Sensory evoked potentials decreased progressively from the resting level of 100% to 53.0% ± 7.2% at the 3rd hour. Intracranial pressure, measured by epidural pressure on the occluded side, increased rapidly during the first 3 hours, from 10.6 ± 0.3 to about 30 cm H2O. In the animals with trapping, the decreases in rCBF and declines of SEP were significantly less than those in the embolized animals, and no evident brain swelling was observed. This study demonstrates that MCA trunk occlusion by silicone cylinder embolization produces a more marked decrease in deep CBF, with diminution of SEP and increase in ICP, than that produced by trapping.

Asymmetric Cerebral Blood Flow Patterns in Migraine

Cephalalgia ◽  
1987 ◽  
Vol 7 (4) ◽  
pp. 245-248 ◽  
Author(s):  
Steven R Levine ◽  
K M A Welch ◽  
James R Ewing ◽  
Wendy M Robertson
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Asymmetry Index ◽  
Regional Cerebral Blood ◽  
Free Interval ◽  
Eeg Abnormalities ◽  
Migraine Group ◽  
The Common ◽  
Blood Flow Patterns

Although asymmetric EEG abnormalities have been reported during the headache-free period in migraineurs, asymmetries of regional cerebral blood flow (rCBF) have not been studied. Headache-free rCBF values measured by 133Xe inhalation were lower in migraineurs than in controls. Interhemispheric CBF and regional (anterior versus posterior) CBF did not differ between the groups. When a novel scoring system was used to obtain a mean asymmetry index (MAI), the MAI of the classiccomplicated group was significantly higher than that of the controls but not significantly different from that of the common migraine group. These data suggest that in the headache-free interval rCBF asymmetries, variable in location, exist in classiccomplicated migraineurs. These rCBF changes may be related to the cause or the effect of the focal neurologic dysfunction that occurs during an attack in these patients

Continuous monitoring of regional cerebral blood flow: experimental and clinical validation of a novel thermal diffusion microprobe

2000 ◽  
Vol 93 (2) ◽  
pp. 265-274 ◽  
Author(s):  
Peter Vajkoczy ◽  
Harry Roth ◽  
Peter Horn ◽  
Thomas Lucke ◽  
Claudius Thomé ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Thermal Diffusion ◽  
Regional Cerebral Blood Flow ◽  
Linear Regression Analysis ◽  
Secondary Brain Injury ◽  
Regional Cerebral Blood ◽  
Content Type ◽  
Arterial Blood ◽  
Fine Print

Object. Current clinical neuromonitoring techniques lack adequate surveillance of cerebral perfusion. In this article, a novel thermal diffusion (TD) microprobe is evaluated for the continuous and quantitative assessment of intraparenchymal regional cerebral blood flow (rCBF).Methods. To characterize the temporal resolution of this new technique, rCBF measured using the TD microprobe (TD-rCBF) was compared with rCBF levels measured by laser Doppler (LD) flowmetry during standardized variations of CBF in a sheep model. For validation of absolute values, the microprobe was implanted subcortically (20 mm below the level of dura) into 16 brain-injured patients, and TD-rCBF was compared with simultaneous rCBF measurements obtained using stable xenon-enhanced computerized tomography scanning (sXe-rCBF). The two techniques were compared using linear regression analysis as well as the Bland and Altman method.Stable TD-rCBF measurements could be obtained throughout all 3- to 5-hour sheep experiments. During hypercapnia, TD-rCBF increased from 49.3 ± 15.8 ml/100 g/min (mean ± standard deviation) to 119.6 ± 47.3 ml/100 g/min, whereas hypocapnia produced a decline in TD-rCBF from 51.2 ± 12.8 ml/100 g/min to 39.3 ± 5.6 ml/100 g/min. Variations in mean arterial blood pressure revealed an intact autoregulation with pressure limits of approximately 65 mm Hg and approximately 170 mm Hg. After cardiac arrest TD-rCBF declined rapidly to 0 ml/100 g/min. The dynamics of changes in TD-rCBF corresponded well to the dynamics of the LD readings. A comparison of TD-rCBF and sXe-rCBF revealed a good correlation (r = 0.89; p <0.0001) and a mean difference of 1.1 ± 5.2 ml/100 g/min between the two techniques.Conclusions. The novel TD microprobe provides a sensitive, continuous, and real-time assessment of intraparenchymal rCBF in absolute flow values that are in good agreement with sXe-rCBF measurements. This study provides the basis for the integration of TD-rCBF into multimodal monitoring of patients who are at risk for secondary brain injury.

Increase in regional cerebral blood flow following experimental arterial air embolism

1971 ◽  
Vol 34 (5) ◽  
pp. 665-671 ◽  
Author(s):  
Norval M. Simms ◽  
George S. Kush ◽  
Don M. Long ◽  
Merle K. Loken ◽  
Lyle A. French
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Air Embolism ◽  
Regional Cerebral Blood ◽  
Pathogenetic Mechanism ◽  
Content Type ◽  
Flow Response ◽  
The Mean ◽  
The Right

✓ Acute intracranial hemodynamic alterations consequent to arterial air embolism were studied in the dog using the radioxenon clearance technique. In eight dogs, the mean pre-embolic (control) hemispheric flow was 28.3 ml/100 gm/min. Following the injection of varying amounts of air into the right vertebral artery, there was an augmentation in the measured cerebral blood flow in all animals. Statistical analysis revealed the flow response to be independent of the amounts of air used in these experiments. The mean post-embolic cerebral blood flow was 39.3 ml/100 gm/min, representing a statistically significant increase of 11.0 ml/100 gm/min. Although the post-embolic supernormal flow may be due to the interaction of multiple pathophysiologic factors, air-induced traumatic vasodilatation is advocated as the most important pathogenetic mechanism. Prolonged vasodilatation with loss of autoregulation results in physiological shunting of blood through the affected capillary beds. Alterations in the intracerebral vasculature due to arterial air embolism are compared with studies by other investigators who have observed the effects in extracerebral vessels.

Reduction of regional cerebral blood flow during brain retraction pressure in the rat

1982 ◽  
Vol 56 (6) ◽  
pp. 826-829 ◽  
Author(s):  
Jarl Rosenørn ◽  
Nils H. Diemer
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Brain Cortex ◽  
Focal Cerebral Ischemia ◽  
Brain Infarction ◽  
Ischemic Damage ◽  
Regional Cerebral Blood ◽  
Content Type ◽  
Brain Retraction

✓ The use of brain retractors in intracranial operations may lead to focal cerebral ischemia and thereby cause brain infarction. To estimate the risk of ischemic damages, the authors investigated the regional cerebral blood flow (rCBF) in rats by means of autoradiography with 14C-iodoantipyrine at different brain retractor pressures (BRP). A reduction in rCBF to between 10 and 75 ml/100 gm/min with 20 mm Hg of BRP for 30 minutes was found in brain cortex lying under the retractor (normal 55 to 150 ml/100 gm/min). With a BRP of 30 mm Hg for 30 minutes, rCBF was reduced to between 0 and 40 ml/100 gm/min, and with a BRP of 40 mm Hg for 15 minutes rCBF was 0 to 15 ml/100 gm/min. The rCBF in the basal ganglia remained unchanged. Even with a BRP of 20 mm Hg for 30 minutes, there seemed to be a risk of focal ischemic damage.

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