Brain blood volume and blood flow in patients with plateau waves

1985 ◽  
Vol 63 (4) ◽  
pp. 556-561 ◽  
Author(s):  
Minoru Hayashi ◽  
Hidenori Kobayashi ◽  
Yuji Handa ◽  
Hirokazu Kawano ◽  
Masanori Kabuto
Keyword(s):  
Blood Flow ◽  
Caudate Nucleus ◽  
Frontal Lobe ◽  
Blood Volume ◽  
Temporal Lobe ◽  
Clinical Symptoms ◽  
Systemic Blood Pressure ◽  
Content Type ◽  
Rapid Sequence ◽  
Plateau Waves

✓ Plateau waves, characterized by acute transient rises of the intracranial pressure (ICP), are accompanied by a marked decrease of the cerebral perfusion pressure. Patients with plateau waves, however, often show no clinical symptoms of ischemia of the brain stem, such as vasopressor response or impairment of consciousness during the waves. The authors studied brain blood volume and blood flow with dynamic computerized tomography using rapid-sequence scanning in patients with plateau waves identified during continuous ICP recording. Following an intravenous bolus injection of contrast medium, density-versus-time curves were obtained for the regions of interest; that is, the frontal lobe, the temporal lobe, the caudate nucleus, the putamen, and the pons. The dynamic studies were undertaken when the ICP was high during a plateau-wave phase and when it was low during an interval phase between two plateau waves. The results indicate that, in the cerebral hemisphere (frontal lobe, temporal lobe, caudate nucleus, and putamen), plateau waves were accompanied by an increase in blood volume and, at the same time, a decrease in blood flow. In the pons, however, both the blood volume and blood flow showed little change during plateau waves as compared with the intervals between two plateau waves. These observations may explain why there is no rise in the systemic blood pressure and why patients are often alert during plateau waves.

Pathophysiology of periventricular tissue changes with raised CSF pressure in cats

1983 ◽  
Vol 59 (4) ◽  
pp. 606-611 ◽  
Author(s):  
Gary A. Rosenberg ◽  
Linda Saland ◽  
Walter T. Kyner
Keyword(s):  
Blood Flow ◽  
Steady State ◽  
White Matter ◽  
Caudate Nucleus ◽  
Clinical Symptoms ◽  
Periventricular White Matter ◽  
Content Type ◽  
Acute Hydrocephalus ◽  
Tissue Changes ◽  
Adult Cats

✓ Intraventricular pressure (IVP) is increased in the early stages of acute hydrocephalus. Pressure falls, however, when compensatory routes for cerebrospinal fluid (CSF) absorption develop. In order to better understand the pathophysiology of acute hydrocephalus, the authors performed ventriculocisternal perfusions on adult cats with outflow pressures maintained at either −5, 20, or 40 cm H2O. Cerebral blood flow (CBF) was determined by the iodoantipyrine method. Penetration of an extracellular marker, horseradish peroxidase (HRP), was visualized histologically. Capillary transfer of radiolabeled molecules from CSF to blood was measured by steady-state tissue clearance. Increased IVP had several effects: 1) significant reduction in mean CBF in the periventricular white matter; 2) penetration of the HRP into deep white matter; and 3) prolongation of steady-state tissue clearance half-time for (14C)-ethylene glycol in the caudate nucleus. Reduced blood flow to periventricular white matter and impaired molecular clearance in the caudate nucleus may contribute to the clinical symptoms in acute hydrocephalus.

Regional brain tissue pressure gradients created by expanding extradural temporal mass lesion

1997 ◽  
Vol 86 (3) ◽  
pp. 505-510 ◽  
Author(s):  
Christopher E. Wolfla ◽  
Thomas G. Luerssen ◽  
Robin M. Bowman
Keyword(s):  
Intracranial Pressure ◽  
Frontal Lobe ◽  
Brain Tissue ◽  
Temporal Lobe ◽  
Mass Lesion ◽  
Pressure Monitor ◽  
Tissue Pressure ◽  
Content Type ◽  
Regional Brain ◽  
The Right

✓ A porcine model of regional intracranial pressure was used to compare regional brain tissue pressure (RBTP) changes during expansion of an extradural temporal mass lesion. Measurements of RBTP were obtained by placing fiberoptic intraparenchymal pressure monitors in the right and left frontal lobes (RF and LF), right and left temporal lobes (RT and LT), midbrain (MB), and cerebellum (CB). During expansion of the right temporal mass, significant RBTP gradients developed in a reproducible pattern: RT > LF = LT > RF > MB > CB. These gradients appeared early, widened as the volume of the mass increased, and persisted for the entire duration of the experiment. The study indicates that RBTP gradients develop in the presence of an extradural temporal mass lesion. The highest RBTP was recorded in the ipsilateral temporal lobe, whereas the next highest was recorded in the contralateral frontal lobe. The RBTP that was measured in either frontal lobe underestimated the temporal RBTP. These results indicated that if a frontal intraparenchymal pressure monitor is used in a patient with temporal lobe pathology, the monitor should be placed on the contralateral side and a lower threshold for therapy of increased intracranial pressure should be adopted. Furthermore, this study provides further evidence that reliance on a single frontal intraparenchymal pressure monitor may not detect all areas of elevated RBTP.

Early changes measured by magnetic resonance imaging in cerebral blood flow, blood volume, and blood-brain barrier permeability following dexamethasone treatment in patients with brain tumors

1999 ◽  
Vol 90 (2) ◽  
pp. 300-305 ◽  
Author(s):  
Leif Østergaard ◽  
Fred H. Hochberg ◽  
James D. Rabinov ◽  
A. Gregory Sorensen ◽  
Michael Lev ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Magnetic Resonance ◽  
Brain Tumors ◽  
Mr Imaging ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Clinical Effects ◽  
Content Type ◽  
Fine Print

Object. In this study the authors assessed the early changes in brain tumor physiology associated with glucocorticoid administration. Glucocorticoids have a dramatic effect on symptoms in patients with brain tumors over a time scale ranging from minutes to a few hours. Previous studies have indicated that glucocorticoids may act either by decreasing cerebral blood volume (CBV) or blood-tumor barrier (BTB) permeability and thereby the degree of vasogenic edema.Methods. Using magnetic resonance (MR) imaging, the authors examined the acute changes in CBV, cerebral blood flow (CBF), and BTB permeability to gadolinium-diethylenetriamine pentaacetic acid after administration of dexamethasone in six patients with brain tumors. In patients with acute decreases in BTB permeability after dexamethasone administration, changes in the degree of edema were assessed using the apparent diffusion coefficient of water.Conclusions. Dexamethasone was found to cause a dramatic decrease in BTB permeability and regional CBV but no significant changes in CBF or the degree of edema. The authors found that MR imaging provides a powerful tool for investigating the pathophysiological changes associated with the clinical effects of glucocorticoids.

Intracranial pressure in the normal monkey while awake and asleep

1979 ◽  
Vol 51 (2) ◽  
pp. 206-210 ◽  
Author(s):  
Gündüz Gücer ◽  
Lawrence J. Viernstein
Keyword(s):  
Blood Pressure ◽  
Intracranial Pressure ◽  
Systemic Blood Pressure ◽  
Macaque Monkey ◽  
Short Term ◽  
Content Type ◽  
Plateau Waves ◽  
Normal Monkey ◽  
The Mean ◽  
Cervical Ganglia

✓ Intracranial pressure (ICP) was recorded continuously by telemetry in seven normal monkeys trained to eat, sleep, and live in a primate chair. Electroencephalography, electromyography, and blood pressure were also measured by conventional means. During wakefulness and all stages of sleep except desynchronized sleep, the ICP record showed small short-term variations in pressure. However, during desynchronized sleep, the mean ICP rose on the average to 170 ± 6 mm H2O above the ICP levels in the other states of sleep, and the pulsation pressure variation increased by a factor of three. The episodes occurred 10 ± 2 times during the night and lasted for 6.8 ± 1.4 minutes, during which the average systemic blood pressure decreased by 19 ± 1.6 mm Hg. These ICP waves occurring during desynchronized sleep resemble the plateau waves described by Lundberg, but are of smaller magnitude and they appear to be a normal characteristic of sleep in the macaque monkey. Bilateral sympathectomy of the superior cervical ganglia in four of the monkeys did not alter significantly the duration, amplitude, or frequency of occurrence of the ICP waves during desynchronized sleep.

Microvascular bypass surgery

1976 ◽  
Vol 44 (6) ◽  
pp. 712-714 ◽  
Author(s):  
Norman Chater ◽  
Robert Spetzler ◽  
Kent Tonnemacher ◽  
Charles B. Wilson
Keyword(s):  
Frontal Lobe ◽  
Temporal Lobe ◽  
Bypass Surgery ◽  
Angular Gyrus ◽  
Anatomical Studies ◽  
Content Type ◽  
Cortical Areas ◽  
Cortical Vessel ◽  
Suitable Location ◽  
Fine Print

✓ Microvascular anatomical studies were performed to ascertain the most suitable cortical vessel for extracranial-intracranial arterial bypass (EIAB). The three most commonly used cortical areas (the tip of the frontal lobe, the tip of the temporal lobe, and the area at the angular gyrus) were examined in detail. Because of their accessibility and size, the cortical arteries in the area of the angular gyrus offer the most suitable location for creating an EIAB.

Acute cerebral blood flow response to dopamine-induced hypertension after subarachnoid hemorrhage

1994 ◽  
Vol 80 (5) ◽  
pp. 857-864 ◽  
Author(s):  
Joseph M. Darby ◽  
Howard Yonas ◽  
Elizabeth C. Marks ◽  
Susan Durham ◽  
Robert W. Snyder ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Subarachnoid Hemorrhage ◽  
Aneurysmal Subarachnoid Hemorrhage ◽  
Systemic Blood Pressure ◽  
Content Type ◽  
Arterial Blood ◽  
Induced Hypertension ◽  
Fine Print

✓ The effects of dopamine-induced hypertension on local cerebral blood flow (CBF) were investigated in 13 patients suspected of suffering clinical vasospasm after aneurysmal subarachnoid hemorrhage (SAH). The CBF was measured in multiple vascular territories using xenon-enhanced computerized tomography (CT) with and without dopamine-induced hypertension. A territorial local CBF of 25 ml/100 gm/min or less was used to define ischemia and was identified in nine of the 13 patients. Raising mean arterial blood pressure from 90 ± 11 mm Hg to 111 ± 13 mm Hg (p < 0.05) via dopamine administration increased territorial local CBF above the ischemic range in more than 90% of the uninfarcted territories identified on CT while decreasing local CBF in one-third of the nonischemic territories. Overall, the change in local CBF after dopamine-induced hypertension was correlated with resting local CBF at normotension and was unrelated to the change in blood pressure. Of the 13 patients initially suspected of suffering clinical vasospasm, only 54% had identifiable reversible ischemia. The authors conclude that dopamine-induced hypertension is associated with an increase in flow in patients with ischemia after SAH. However, flow changes associated with dopamine-induced hypertension may not be entirely dependent on changes in systemic blood pressure. The direct cerebrovascular effects of dopamine may have important, yet unpredictable, effects on CBF under clinical pathological conditions. Because there is a potential risk of dopamine-induced ischemia, treatment may be best guided by local CBF measurements.

Effect of chemical sympathectomy on cerebral blood flow in rats

1991 ◽  
Vol 75 (6) ◽  
pp. 906-910 ◽  
Author(s):  
Hidenori Kobayashi ◽  
Minoru Hayashi ◽  
Hirokazu Kawano ◽  
Yuji Handa ◽  
Masanori Kabuto ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Systemic Blood Pressure ◽  
Treated Group ◽  
Control Group ◽  
Electron Microscopic ◽  
Content Type ◽  
Left Lateral Ventricle ◽  
6 Hydroxydopamine ◽  
Fine Print

✓ Thirty male Wistar rats, weighing 350 to 400 gm each, received stereotactic injections of 6-hydroxydopamine (300 µg/kg) into the left lateral ventricle. The same amount of saline was injected into a control group of 15 rats. Seven days after this procedure, cerebral blood flow (CBF) was measured by the hydrogen clearance method. A hypertensive condition at a mean arterial pressure of about 160 mm Hg was maintained for 1 hour by intravenous infusion of phenylephrine. In the 6-hydroxydopamine-treated group, CBF increased significantly after the elevation of systemic blood pressure compared with that in the control group, and cerebral autoregulation was impaired. After a 1-hour study, the specific gravity of the cerebral tissue in the treated group significantly decreased; electron microscopic studies at that time revealed brain edema. It is suggested that depletion of brain noradrenaline levels causes a disturbance in cerebral microvascular tone and renders the cerebral blood vessels more vulnerable to hypertension.

Effects of methylprednisolone on peritumoral brain edema

1983 ◽  
Vol 59 (4) ◽  
pp. 612-619 ◽  
Author(s):  
Kazuo Yamada ◽  
Yukitaka Ushio ◽  
Toru Hayakawa ◽  
Norio Arita ◽  
Noriko Yamada ◽  
...  
Keyword(s):  
Blood Flow ◽  
Brain Edema ◽  
Capillary Permeability ◽  
Clinical Symptoms ◽  
Treated Group ◽  
Untreated Group ◽  
Content Type ◽  
Intracerebral Transplantation ◽  
Edema Fluid ◽  
Peritumoral Brain Edema

✓ Peritumoral brain edema was produced by intracerebral transplantation of Walker 256 tumor in rats. Local cerebral blood flow (LCBF), local cerebral glucose utilization (LCGU), and capillary permeability were studied in untreated and methylprednisolone-treated rats by quantitative autoradiography. In the untreated group, LCBF and LCGU were widely depressed in the cortex and deep structures of the hemisphere ipsilateral to the tumor. In the methylprednisolone-treated animals, LCBF and LCGU were significantly better than in the untreated animals. Capillary permeability was highly increased in the viable part of the tumor in the untreated animals. In the methylprednisolone-treated group, capillary permeability of the tumor was significantly lower than that in the untreated group. These results may suggest that increase in capillary permeability of the tumor is the major source for edema fluid production, and that methylprednisolone improves brain edema by decreasing capillary permeability of the tumor. Decrease in edema fluid formation may result in restoration of blood flow and glucose metabolism in the adjacent brain tissue, and may improve clinical symptoms and signs.

Relationship of cerebral blood flow to cardiac output, mean arterial pressure, blood volume, and alpha and beta blockade in cats

1980 ◽  
Vol 52 (6) ◽  
pp. 745-754 ◽  
Author(s):  
Dudley H. Davis ◽  
Thoralf M. Sundt
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Cerebral Blood Flow ◽  
Blood Volume ◽  
Cerebral Autoregulation ◽  
Major Change ◽  
Beta Blockade ◽  
Content Type ◽  
Therapeutic Implications ◽  
Arterial Blood

✓ The relationship among cerebral blood flow (CBF), blood volume, cardiac output (CO), and mean arterial blood pressure (MABP) at varying levels of arterial CO2 tensions (PaCO2) were studied in 70 normal cats. The CBF was measured from the clearance curve of xenon−133 and CO with a thermal dilution catheter placed in the pulmonary artery. The CBF, CO, and MABP values varied appropriately with changes in PaCO2, confirming the reliability of the preparations and the presence of normal autoregulatory responses. Moderate hypovolemia that did not change MABP did, nevertheless, significantly decrease CO and CBF. In an effort to determine if this decrease in CO and CBF were coupled responses, the effects of beta stimulation, hypervolemia, and alpha and beta blockade were investigated. Propranolol, in a dosage insufficient to change MABP, decreased both CO and CBF. This agent abolished the CO response to elevations in PaCO2 but not the CBF response, making it unlikely that this CBF reduction resulted from impaired cerebral autoregulation. Isoproterenol, which, in contrast to propranolol, does not cross the normal blood-brain barrier, alone or in combination with phenoxybenzamine, produced a 38% and 72% increase in CO, respectively, without a change in CBF. Alpha blockade (no major change in CO) and beta blockade (major decrease in CO) did not significantly effect cerebral autoregulation to changes in MABP from angiotensin. The ability of the brain to resist increases in MABP and CO and maintain normal CBF is explained by normal cerebral autoregulation. However, its vulnerability to modest decreases in blood volume, which cannot be attributed to variations in perfusion pressure, is unexplained but obviously has important therapeutic implications. This may be related to reduction in CO, changes in autonomic activity, or a decrease in the size of the perfused capillary bed.

Effects of experimental intracerebral hemorrhage on blood flow, capillary permeability, and histochemistry

1987 ◽  
Vol 66 (4) ◽  
pp. 555-562 ◽  
Author(s):  
Fredrik P. Nath ◽  
Paul T. Kelly ◽  
Alistair Jenkins ◽  
A. David Mendelow ◽  
David I. Graham ◽  
...  
Keyword(s):  
Blood Flow ◽  
Intracerebral Hemorrhage ◽  
Caudate Nucleus ◽  
Brain Damage ◽  
Structural Damage ◽  
Time Course ◽  
Capillary Permeability ◽  
Autologous Blood ◽  
Ischemic Damage ◽  
Content Type

✓ Experimental intracerebral hemorrhage has been shown to cause extensive cerebral ischemia. This study was performed to ascertain the time course of these changes and also to examine the type of brain damage that may occur under such circumstances. Halothane anesthesia was induced in rats, and 25 µl autologous blood was injected into the caudate nucleus; the effects were studied with autoradiographic measurement of local cerebral blood flow and capillary permeability, and also by light microscopy and histochemical techniques. Blood flow returned to normal or to slightly increased levels within the first 3 hours, and ischemic levels of flow were found to persist only to a marginal degree beyond 10 minutes after the lesions were made. Capillary permeability was maximum during the first 30 minutes after the hemorrhage and diminished with time. Structural evidence of ischemic damage was localized to the cortex overlying the hemorrhage, but was not seen in the caudate nucleus. Nevertheless, histochemical investigation did reveal an area of disturbed enzyme function in the striatum. This finding of biochemical disturbance without structural evidence of ischemic damage reveals that there is an area around the hematoma that, although demonstrating disturbed function, does not show structural damage, and the milieu of this partially injured brain may be implicated in the delayed development of the ischemic brain damage that follows intracerebral hemorrhage in man.

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