Central cholinergic control of cerebral blood flow in the baboon

1975 ◽  
Vol 43 (6) ◽  
pp. 689-705 ◽  
Author(s):  
Minoru Aoyagi ◽  
John Stirling Meyer ◽  
Vinod D. Deshmukh ◽  
Erwin O. Ott ◽  
Yukio Tagashira ◽  
...  
Keyword(s):  
Blood Flow ◽  
Body Weight ◽  
Cerebral Blood Flow ◽  
Content Type ◽  
Chemical Index ◽  
Anticholinesterase Agent ◽  
Before And After ◽  
Autoregulation Index ◽  
Cerebral Vascular Resistance ◽  
Fine Print

✓ Cerebral autoregulation and vasomotor responsiveness to carbon dioxide (CO2) were measured quantitatively by the use of the autoregulation index and chemical index, respectively, in normal baboons before and after intravertebral and intracarotid infusion of the anticholinesterase agent, neostigmine methylsulfate (Prostigmin). Continuous measurements were made of cerebral blood flow (measured as bilateral internal jugular venous outflow), arterial and cerebral venous pO2 and pCO2, cerebral arteriovenous oxygen differences, and endotracheal CO2. The effect of intravertebral infusion of neostigmine (12.5 µg/kg body weight) was compared to intracarotid infusion of neostigmine (25 µg/kg body weight) for assessment of any specific action of the drug on a hypothetical cholinergic vasomotor center, presumed to be located in the territory of the vertebrobasilar supply. No significant or persistent changes in cerebral blood flow (CBF) and cerebral metabolic rate for oxygen (CMRO2) followed either intravertebral or intracarotid infusion of neostigmine. Cerebral vascular resistance (CVR) and cerebral perfusion pressure (CPP), however, decreased significantly after intravertebral infusion. Cerebral autoregulatory vasoconstriction during increases of CPP was significantly reduced following both intravertebral and intracarotid infusion. Cerebral autoregulatory vasodilatation was not altered as CPP was lowered. Cerebral vasodilatory reactivity to CO2 inhalation was significantly enhanced following intravertebral neostigmine but not following intracarotid neostigmine. Cerebral vasoconstrictive response to hyperventilation was not influenced by neostigmine. These results support the view that central cholinergic cerebrovascular influences exist, and are vasodilatory in nature.

Cerebrovascular effects of hypocapnia during adenosine-induced arterial hypotension

1985 ◽  
Vol 63 (6) ◽  
pp. 937-943 ◽  
Author(s):  
David J. Boarini ◽  
Neal F. Kassell ◽  
James A. Sprowell ◽  
Julie J. Olin ◽  
Hans C. Coester
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Arterial Hypotension ◽  
Content Type ◽  
Blood Flows ◽  
Before And After ◽  
Regional Blood Flows ◽  
Fine Print

✓ Profound arterial hypotension is à commonly used adjunct in surgery for aneurysms and arteriovenous malformations. Hyperventilation with hypocapnia is also used in these patients to increase brain slackness. Both measures reduce cerebral blood flow (CBF). Of concern is whether CBF is reduced below ischemic thresholds when both techniques are employed together. To determine this, 12 mongrel dogs were anesthetized with morphine, nitrous oxide, and oxygen, and then paralyzed with pancuronium and hyperventilated. Arterial pCO2 was controlled by adding CO2 to the inspired gas mixture. Cerebral blood flow was measured at arterial pCO2 levels of 40 and 20 mm Hg both before and after mean arterial pressure was lowered to 40 mm Hg with adenosine enhanced by dipyridamole. In animals where PaCO2 was reduced to 20 mm Hg and mean arterial pressure was reduced to 40 mm Hg, cardiac index decreased 42% from control and total brain blood flow decreased 45% from control while the cerebral metabolic rate of oxygen was unchanged. Hypocapnia with hypotension resulted in small but statistically significant reductions in all regional blood flows, most notably in the brain stem. The reported effects of hypocapnia on CBF during arterial hypotension vary depending on the hypotensive agents used. Profound hypotension induced with adenosine does not eliminate CO2 reactivity, nor does it lower blood flow to ischemic levels in this model, even in the presence of severe hypocapnia.

Cerebral blood flow in patients with normal-pressure hydrocephalus before and after shunting

1987 ◽  
Vol 66 (3) ◽  
pp. 379-387 ◽  
Author(s):  
Sissel Vorstrup ◽  
John Christensen ◽  
Flemming Gjerris ◽  
P. Soelberg Sørensen ◽  
Anne Marie Thomsen ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Ct Scan ◽  
Normal Pressure Hydrocephalus ◽  
Normal Pressure ◽  
Low Flow ◽  
Ventricular Size ◽  
Content Type ◽  
Before And After ◽  
Fine Print

✓ Cerebral blood flow (CBF) was measured by xenon-133 inhalation and single photon emission tomography in 17 demented patients with normal-pressure hydrocephalus before and after shunt treatment. All patients had a decreased conductance to outflow (Cout) of cerebrospinal fluid as measured by lumboventricular perfusion (COut < 0.12 ml ⋅ mm Hg−1 ⋅ min−1). Computerized tomography (CT) scanning, clinical assessment, and neuropsychological grading were performed pre- and postoperatively. The preoperative CBF studies revealed abnormal flow patterns in all patients. Fourteen patients showed moderate-sized, large, or very large central low-flow areas, and four patients had reduced flow bilaterally in the occipital and contiguous temporoparietal regions. After shunting, six patients had a significant reduction in the size of the central low-flow area on the CBF map, agreeing well with the changes of ventricular size on the CT scan. All six patients showed an improvement in either clinical or neuropsychological grading. In 10 of the remaining 11 patients flow patterns were essentially unchanged; one patient deteriorated further. Four of these 11 patients improved on postoperative clinical or neuropsychological testing. Thus, a positive correlation was found between the changes in CBF and the reduction of the ventricular size on the CT scan, but changes in CBF as measured by the present technique did not accompany improvement in the functional state in all patients.

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.

Transcorneal stimulation of trigeminal nerve afferents to increase cerebral blood flow in rats with cerebral vasospasm: a noninvasive method to activate the trigeminovascular reflex

2002 ◽  
Vol 97 (5) ◽  
pp. 1179-1183 ◽  
Author(s):  
Basar Atalay ◽  
Hayrunnisa Bolay ◽  
Turgay Dalkara ◽  
Figen Soylemezoglu ◽  
Kamil Oge ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cerebral Vasospasm ◽  
Trigeminal Nerve ◽  
Nerve Endings ◽  
Noninvasive Method ◽  
Direct Stimulation ◽  
Content Type ◽  
Fine Print ◽  
Stimulation Of

Object. The goal of this study was to investigate whether stimulation of trigeminal afferents in the cornea could enhance cerebral blood flow (CBF) in rats after they have been subjected to experimental subarachnoid hemorrhage (SAH). Cerebral vasospasm following SAH may compromise CBF and increase the risks of morbidity and mortality. Currently, there is no effective treatment for SAH-induced vasospasm. Direct stimulation of the trigeminal nerve has been shown to dilate constricted cerebral arteries after SAH; however, a noninvasive method to activate this nerve would be preferable for human applications. The authors hypothesized that stimulation of free nerve endings of trigeminal sensory fibers in the face might be as effective as direct stimulation of the trigeminal nerve. Methods. Autologous blood obtained from the tail artery was injected into the cisterna magna of 10 rats. Forty-eight and 96 hours later (five rats each) trigeminal afferents were stimulated selectively by applying transcorneal biphasic pulses (1 msec, 3 mA, and 30 Hz), and CBF enhancements were detected using laser Doppler flowmetry in the territory of the middle cerebral artery. Stimulation-induced changes in cerebrovascular parameters were compared with similar parameters in sham-operated controls (six rats). Development of vasospasm was histologically verified in every rat with SAH. Corneal stimulation caused an increase in CBF and blood pressure and a net decrease in cerebrovascular resistance. There were no significant differences between groups for these changes. Conclusions. Data from the present study demonstrate that transcorneal stimulation of trigeminal nerve endings induces vasodilation and a robust increase in CBF. The vasodilatory response of cerebral vessels to trigeminal activation is retained after SAH-induced vasospasm.

Improvement in cerebral blood flow and metabolism following subarachnoid hemorrhage in response to prophylactic administration of the hydroxyl radical scavenger, AVS, (±)-N,N′-propylenedinicotinamide: a positron emission tomography study in rats

2000 ◽  
Vol 92 (6) ◽  
pp. 1009-1015 ◽  
Author(s):  
Seiji Yamamoto ◽  
Weiyu Teng ◽  
Shigeru Nishizawa ◽  
Takeharu Kakiuchi ◽  
Hideo Tsukada
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Emission Tomography ◽  
Radical Scavenger ◽  
Content Type ◽  
Prophylactic Administration ◽  
Positron Emission ◽  
Hydroxyl Radical Scavenger ◽  
Fine Print

Object. The hydroxyl radical scavenger (±)-N,N′-propylenedinicotinamide (AVS) has been shown to ameliorate the occurrence of vasospasm following experimental subarachnoid hemorrhage (SAH) and to reduce the incidence of delayed ischemic neurological deficits (DINDs) in patients with SAH. The authors investigated whether prophylactic administration of AVS could improve cerebral blood flow (CBF) and cerebral glucose utilization (CGU) following SAH in rats.Methods. Anesthetized rats were subjected to intracisternal injection of blood (SAH group) or saline (control group). Either AVS (1 mg/kg/min) or saline (vehicle group) was continuously injected into the rat femoral vein. Forty-eight hours later, positron emission tomography scanning was used with the tracers 15O-H2O and 18F-2-fluoro-d-glucose to analyze quantitatively CBF and CGU, respectively, in the frontoparietal and occipital regions (12 regions of interest/group).In SAH rats receiving only vehicle, CBF decreased significantly (p < 0.05, Tukey's test) and CGU tended to decrease, compared with values obtained in control (non-SAH) rats receiving vehicle. In rats that were subjected to SAH, administration of AVS significantly (p < 0.05, Tukey's test) improved CBF and CGU in both the frontoparietal and occipital regions compared with administration of vehicle alone.Conclusions. Prophylactic administration of AVS improves CBF and CGU in the rat brain subjected to SAH, and can be a good pharmacological treatment for the prevention of DINDs following SAH.

Cerebral blood flow measurements and electroencephalograms during carotid endarterectomy

1974 ◽  
Vol 41 (3) ◽  
pp. 310-320 ◽  
Author(s):  
Thoralf M. Sundt ◽  
Frank W. Sharbrough ◽  
Robert E. Anderson ◽  
John D. Michenfelder
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Endarterectomy ◽  
Carbon Dioxide Tension ◽  
Initial Slope ◽  
Flow Measurements ◽  
Content Type ◽  
Blood Flow Measurements ◽  
Electroencephalogram Eeg ◽  
Fine Print

✓ Ninety-three endarterectomies for carotid stenosis were monitored with cerebral blood flow (CBF) measurements, and 113 with both CBF measurements and a continuous electroencephalogram (EEG). Significant CBF increase occurred only when carotid endarterectomy was for a stenosis greater than 90%. A high correlation between CBF and EEG indicated when a shunt was required. To sustain a normal EEG, the CBF ascertained by the initial slope technique must be 18 ml/100 gm/min at an arterial carbon dioxide tension (PaCO2) of 40 torr. The degree of EEG change below this level during occlusion reflected the severity of reduced blood flow and was reversible with replacement of a shunt. The value and limitations of these monitoring techniques and a concept of ischemic tolerance and critical CBF are discussed.

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.

Endovascular occlusion of intracranial vessels for curative treatment of unclippable aneurysms: report of 16 cases

1991 ◽  
Vol 75 (5) ◽  
pp. 694-701 ◽  
Author(s):  
Jonathan E. Hodes ◽  
Armand Aymard ◽  
Y. Pierre Gobin ◽  
Daniel Rüfenacht ◽  
Siegfried Bien ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cerebral Artery ◽  
Basilar Artery ◽  
Posterior Inferior Cerebellar Artery ◽  
Artery Aneurysm ◽  
Neurological Deficits ◽  
Parent Vessel ◽  
Content Type ◽  
Fine Print

✓ Among 121 intracerebral aneurysms presenting at one institution between 1984 and 1989, 16 were treated by endovascular means. All 16 lesions were intradural and intracranial, and had failed either surgical or endovascular attempts at selective exclusion with parent vessel preservation. The lesions included four giant middle cerebral artery (MCA) aneurysms, one giant anterior communicating artery aneurysm, six giant posterior cerebral artery aneurysms, one posterior inferior cerebellar artery aneurysm, one giant mid-basilar artery aneurysm, two giant fusiform basilar artery aneurysms, and one dissecting vertebral artery aneurysm. One of the 16 patients failed an MCA test occlusion and was approached surgically after attempted endovascular selective occlusion. Treatment involved pretreatment evaluation of cerebral blood flow followed by a preliminary parent vessel test occlusion under neuroleptic analgesia with vigilant neurological monitoring. If the test occlusion was tolerated, it was immediately followed by permanent occlusion of the parent vessel with either detachable or nondetachable balloon or coils. The follow-up period ranged from 1 to 8 years. Excellent outcomes were obtained in 12 cases with complete angiographic obliteration of the aneurysm and no new neurological deficits and/or improvement of the pre-embolization symptoms. Four patients died: two related to the procedure, one secondary to rupture of another untreated aneurysm, and the fourth from a postoperative MCA thrombosis after having failed endovascular test occlusion. The angiographic, clinical, and cerebral blood flow criteria for occlusion tolerance are discussed.

Treatment of aneurysmal hemiplegia with dopamine and mannitol

1978 ◽  
Vol 49 (4) ◽  
pp. 525-529 ◽  
Author(s):  
Frederick D. Brown ◽  
Kathryn Hanlon ◽  
Sean Mullan
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Subarachnoid Hemorrhage ◽  
Clinical Improvement ◽  
Content Type ◽  
Remarkable Degree ◽  
Induced Hypertension ◽  
Fine Print

✓ Three patients with severe postoperative hemiplegia and one with hemiplegia following a subarachnoid hemorrhage are presented. None had hematomas. All were treated with dopamine-induced hypertension, mannitol, and large quantities of intravascular fluids. All showed a remarkable degree of clinical improvement, presumably secondary to an increase in cerebral blood flow.

Cerebral blood flow and metabolism in severely head-injured children

1989 ◽  
Vol 71 (1) ◽  
pp. 63-71 ◽  
Author(s):  
J. Paul Muizelaar ◽  
Anthony Marmarou ◽  
Antonio A. F. DeSalles ◽  
John D. Ward ◽  
Richard S. Zimmerman ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Head Injury ◽  
Severe Head Injury ◽  
Cerebral Blood Volume ◽  
Closed Head Injury ◽  
Volume Index ◽  
Content Type ◽  
Gcs Score ◽  
Fine Print

✓ The literature suggests that in children with severe head injury, cerebral hyperemia is common and related to high intracranial pressure (ICP). However, there are very few data on cerebral blood flow (CBF) after severe head injury in children. This paper presents 72 measurements of cerebral blood flow (“CBF15”), using the 133Xe inhalation method, with multiple detectors over both hemispheres in 32 children aged 3 to 18 years (mean 13.6 years) with severe closed head injury (average Glasgow Coma Scale (GCS) score 5.4). In 25 of the children, these were combined with measurements of arteriojugular venous oxygen difference (AVDO2) and of cerebral metabolic rate of oxygen (CMRO2). In 30 patients, the first measurement was taken approximately 12 hours postinjury. In 18 patients, an indication of brain stiffness was obtained by withdrawal and injection of ventricular cerebrospinal fluid and calculation of the pressure-volume index (PVI) of Marmarou. The CBF and CMRO2 data were correlated with the GCS score, outcome, ICP, and PVI. Early after injury, CBF tended to be lower with lower GCS scores, but this was not statistically significant. This trend was reversed 24 hours postinjury, as significantly more hyperemic values were recorded the lower the GCS score, with the exception of the most severely injured patients (GCS score 3). In contrast, mean CMRO2 correlated positively with the GCS score and outcome throughout the course, but large standard deviations preclude making predictions based on CMRO2 measurements in individual patients. Early after injury, there was mild uncoupling between CBF and CMRO2 (CBF above metabolic demands, low AVDO2) and, after 24 hours, flow and metabolism were completely uncoupled with an extremely low AVDO2. Consistently reduced flow was found in only four patients; 28 patients (88%) showed hyperemia at some point in their course. This very high percentage of patients with hyperemia, combined with the lowest values of AVDO2 found in the literature, indicates that hyperemia or luxury perfusion is more prevalent in this group of patients. The three patients with consistently the highest CBF had consistently the lowest PVI: thus, the patients with the most severe hyperemia also had the stiffest brains. Nevertheless, and in contrast to previous reports, no correlation could be established between the course of ICP or PVI and the occurrence of hyperemia, nor was there a correlation between the levels of CBF and ICP at the time of the measurements. The authors argue that this lack of correlation is due to: 1) a definition of hyperemia that is too generous, and 2) the lack of a systematic relationship between CBF and cerebral blood volume. The implications of these findings for therapeutic modes of controlling ICP in children, such as hyperventilation and the use of mannitol, are discussed.

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