Pressure in the sagittal sinus during intracranial hypertension in man

1974 ◽  
Vol 40 (5) ◽  
pp. 603-608 ◽  
Author(s):  
Albert N. Martins ◽  
Arthur I. Kobrine ◽  
Douglas F. Larsen
Keyword(s):  
Brain Tumors ◽  
Intracranial Hypertension ◽  
Cerebral Blood Volume ◽  
Content Type ◽  
Sagittal Sinus ◽  
Sagittal Sinus Pressure ◽  
The Mean ◽  
The Difference ◽  
Spatial Compensation ◽  
Sinus Pressure

✓ Intracranial pressure (ICP) and sagittal sinus pressure (SSP) were measured simultaneously in 12 patients with brain tumors and secondary intracranial hypertension (ICH). In nine, the mean SSP was largely unaffected by changes in ICP. In three, SSP changed with the ICP. In all but one patient, the ICP remained higher than SSP and, as the ICP increased, the difference between the two also increased. Sinograms performed during ICH demonstrated partial collapse of the sinuses in some patients and not in others. The mean SSP in adults with brain tumors appears to respond unpredictably to changes in ICP. Since the rate of cerebrospinal fluid drainage depends upon the gradient between ICP and SSP, intracranial spatial compensation is probably influenced by the response of SSP to ICP. Individuals with gradients that rapidly increase because their sinuses do not collapse probably compensate more rapidly than those whose sinuses do collapse. This assumed difference in the rate of spatial compensation may account for some of the variability of the ICP response to an enlarging intracranial mass or a change in cerebral blood volume.

Dural posterior fossa AVM producing raised sagittal sinus pressure

1977 ◽  
Vol 46 (6) ◽  
pp. 804-810 ◽  
Author(s):  
Eduardo Lamas ◽  
Ramiro D. Lobato ◽  
Javier Esparza ◽  
Luis Escudero
Keyword(s):  
Intracranial Pressure ◽  
Posterior Fossa ◽  
Considerable Increase ◽  
Selective Embolization ◽  
Content Type ◽  
Sagittal Sinus ◽  
Arterial Blood ◽  
Sagittal Sinus Pressure ◽  
Dural Avm ◽  
Sinus Pressure

✓ A patient with raised intracranial pressure secondary to a dural arteriovenous malformation (AVM) of the posterior fossa is presented. Direct shunting of arterial blood into the transverse sigmoid sinus caused a considerable increase of the sagittal sinus pressure (SSP) and elevation of intracranial pressure (ICP). Both ICP and SSP returned to normal values following obliteration of the dural AVM by selective embolization.

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.

Cerebral and cardiovascular responses to changes in head elevation in patients with intracranial hypertension

1983 ◽  
Vol 59 (6) ◽  
pp. 938-944 ◽  
Author(s):  
Quentin J. Durward ◽  
A. Lorne Amacher ◽  
Rolando F. Del Maestro ◽  
William J. Sibbald
Keyword(s):  
Cardiac Output ◽  
Intracranial Hypertension ◽  
Cardiovascular Responses ◽  
Arterial Oxygen ◽  
Optimum Level ◽  
Moderate Degree ◽  
Content Type ◽  
Arterial Oxygen Content ◽  
Head Elevation ◽  
The Mean

✓ To establish if an optimum level of head elevation exists in patients with intracranial hypertension, the authors examined changes in intracranial pressure (ICP), systemic and pulmonary pressures, systemic flows, and intrapulmonary shunt fraction with the patient lying flat, and then with the head elevated at 15°, 30°, and 60°. Cerebral perfusion pressure (CPP) was calculated. The lowest mean ICP was found with elevation of the head to 15° (a fall of −4.5 ± 1.6 mm Hg, p < 0.001) and 30° (a fall of −6.1 ± 3.5 mm Hg, p < 0.001); the CPP and cardiac output were maintained. With elevation of the head to 60°, the mean ICP increased to −3.8 ± 9.3 mm Hg of baseline, while the CPP decreased −7.9 ± 9.3 mm Hg (p < 0.02), and the cardiac index also fell −0.25 ± 0.28 liters/min/sq m (p < 0.01). No significant change in filling pressures, arterial oxygen content, or heart rate was encountered at any level of head elevation. Therefore, a moderate degree (15° or 30°) of head elevation provides a consistent reduction of ICP without concomitant compromise of cardiac function. Lower (0°) or higher (60°) degrees of head elevation may be detrimental to the patient because of changes in the ICP, CPP, and cardiac output.

Utility of relative cerebral blood volume mapping derived from perfusion magnetic resonance imaging in the routine follow up of brain tumors

1997 ◽  
Vol 86 (1) ◽  
pp. 22-27 ◽  
Author(s):  
Tali Siegal ◽  
Rina Rubinstein ◽  
Tzahala Tzuk-Shina ◽  
John M. Gomori
Keyword(s):  
Magnetic Resonance ◽  
Brain Tumors ◽  
Mr Imaging ◽  
Blood Volume ◽  
Clinical Assessment ◽  
Cerebral Blood Volume ◽  
Content Type ◽  
Relative Cerebral Blood Volume ◽  
Fine Print

✓ It was recently demonstrated that imaging of brain tumors by relative cerebral blood volume (CBV) maps reconstructed from dynamic magnetic resonance (MR) data provide similar diagnostic information compared to positron emission tomography (PET) or 201Tl single-photon emission computerized tomography (201Tl-SPECT) scans. The authors used relative CBV mapping for routine follow-up evaluation of patients with brain tumors and compared its sensitivity to diagnostic MR imaging, 201Tl-SPECT and clinical assessment. Fifty-nine patients were prospectively followed using 191 concomitant studies of dual section relative CBV maps, MR imaging, 201Tl-SPECT, and neurological evaluations. Studies were repeated every 2 to 3 months (median three evaluations/patient). The relative CBV maps were graded as relative CBV 0 to 4, where Grades 3 and 4 are indicative of proliferating tumors (four = rapid leak). There were 44 high-grade and 15 low-grade tumors followed during treatment. During the follow-up period a change in relative CBV grade was observed in 56% of the patients, revealing an increasing grade in 72% of them. The rapid leak phenomenon was detected in 35% of all studies and in 81% of those with a worsening relative CBV grade. Tumor progression was detected earlier by relative CBV maps as follows: earlier than MR imaging in 32% of the studies (earlier by a median of 4.5 months; p < 0.01); earlier than 201Tl-SPECT in 63% (median 4.5 months; p < 0.01), and earlier than clinical assessment in 55% (median 6 months; p < 0.01). In 82% of studies with positive MR imaging but negative 201Tl-SPECT, the lesions were smaller than 1.5 cm. The relative CBV maps clearly delineated the appearance of rapid leak in these lesions. Routine use of relative CBV maps that can be implemented on any high-field MR unit and added to the regular MR evaluation provides useful functional information in patients with brain tumors. When used as an adjunct follow-up evaluation it proved more sensitive than the other modalities for early prediction of tumor growth. It is very sensitive to small regional changes, unlike functional imaging such as PET or SPECT scans. Based on previous experience with 76 regional CBV studies, the authors conclude that regional CBV mapping correlates with active tumor and it may separate enhancing scar and radiation injury from infiltrative tumor. A new effect named the rapid leak phenomenon was also observed; this phenomenon, as identified on the regional CBV maps, correlates with high malignancy.

Intracranial venous pressures under conscious sedation and general anesthesia

2017 ◽  
Vol 9 (10) ◽  
pp. 986-989 ◽  
Author(s):  
Daniel M S Raper ◽  
Thomas J Buell ◽  
Ching-Jen Chen ◽  
Dale Ding ◽  
Robert M Starke ◽  
...  
Keyword(s):  
General Anesthesia ◽  
Transverse Sinus ◽  
Jugular Bulb ◽  
Venous Sinus ◽  
Pressure Gradients ◽  
Sagittal Sinus ◽  
Venous Outflow Obstruction ◽  
The Mean ◽  
The Relationship ◽  
Sinus Pressure

IntroductionVenous outflow obstruction has been implicated in the pathophysiology of a subset of patients with idiopathic intracranial hypertension (IIH), and venous sinus stenting (VSS) has emerged as an effective treatment. However, the effect of anesthesia on venous sinus pressure measurements is unpredictable. A more thorough understanding of the effect of the level of anesthesia on intracranial venous pressures might help to better define patients who might benefit most from stent placement.ObjectiveTo compare, in a retrospective cohort study, intracranial venous pressures measured under conscious (CS) sedation versus general anesthesia (GA) and to assess the relationship between anesthetic-dependent venous pressures and outcomes after VSS.MethodsWe performed a retrospective review of a prospectively maintained database to identify patients undergoing angiographic evaluation and VSS for intracranial venous stenosis. Mean venous pressures (MVPs) and trans-stenosis pressure gradients obtained under CS were compared with those measured under GA.ResultsThe maximal MVP was significantly lower under GA (19.8 mm Hg) than CS (21.9 mm Hg; p=0.029). The MVPs in the superior sagittal sinus, torcula, and transverse sinus were lower under GA, but were significantly higher in the sigmoid sinus and jugular bulb under GA (p<0.001). The mean trans-stenosis pressure gradient was also significantly lower under GA (8.6 mm Hg) than CS (12.1 mm Hg; p<0.001). Patients with a larger difference between maximum MVP under GA versus CS were more likely to have normalization of the MVP after VSS (p=0.0008).ConclusionsIntracranial venous pressures are markedly affected by GA. In order to obtain an accurate measurement of MVPs and trans-stenosis gradients, patients undergoing investigation for IIH should undergo cerebral angiography and venous manometry under CS, which provides more reliable data for outcomes after VSS.

scholarly journals Coupling of CSF and sagittal sinus pressure in adult patients with pseudotumour cerebri

2019 ◽  
Vol 162 (5) ◽  
pp. 1001-1009 ◽  
Author(s):  
Afroditi-Despina Lalou ◽  
Marek Czosnyka ◽  
Zofia H. Czosnyka ◽  
Deepa Krishnakumar ◽  
John D. Pickard ◽  
...  
Keyword(s):  
Venous Pressure ◽  
Fluid Pressure ◽  
Venous Drainage ◽  
Infusion Test ◽  
Pseudotumour Cerebri ◽  
Sagittal Sinus ◽  
Sagittal Sinus Pressure ◽  
The Relationship ◽  
Symptoms And Signs ◽  
Sinus Pressure

Abstract Objective Pseudotumour cerebri syndrome (PTCS including idiopathic intracranial hypertension) is characterised by the symptoms and signs of raised cerebrospinal fluid pressure (CSFp) in the absence of ventricular dilatation or an intracranial mass lesion. Its aetiology is unknown in the majority of cases but there is much evidence for impaired CSF absorption. Traditionally, sagittal sinus pressure has been considered to be independent of CSF pressure in adults. However, the discovery of stenoses of intracranial venous sinuses and introduction of venous sinus stenting has highlighted the importance of the venous drainage in PTCS. In this study, we have explored the relationship between CSFp and SSp before and during a CSF infusion test and during CSF drainage. Materials and methods Ten patients (9 females:1 male) with PTCS underwent infusion studies in parallel with direct retrograde cerebral venography. Both SSp and CSFp were recorded at a baseline and during CSFp elevation in a course of a CSF infusion test. The drainage of CSF after the CSF infusion was performed in 7 patients. In 5 cases, jugular venous pressure was also measured. Results CSFp and SSp including their amplitudes correlated significantly and strongly both at baseline (R = 0.96; p = 0.001) and during infusion (R = 0.92; p = 0.0026). During drainage, this correlation was maintained until SSp reached a stable value, whereas CSFp continued to decrease. Conclusions In this series of ten patients with PTCS, CSFp and SSp were coupled, both at baseline and during infusion. The implications of such coupling for the calculation of CSF outflow resistance are discussed.

Document-based approach to improve the accuracy of pairwise comparison in evaluating information retrieval systems

2015 ◽  
Vol 67 (4) ◽  
pp. 408-421
Author(s):  
Sri Devi Ravana ◽  
MASUMEH SADAT TAHERI ◽  
Prabha Rajagopal
Keyword(s):  
Information Retrieval ◽  
Pairwise Comparison ◽  
Current Method ◽  
Statistical Testing ◽  
Test Collection ◽  
Content Type ◽  
Retrieval Systems ◽  
Information Retrieval Systems ◽  
The Mean ◽  
The Difference

Purpose – The purpose of this paper is to propose a method to have more accurate results in comparing performance of the paired information retrieval (IR) systems with reference to the current method, which is based on the mean effectiveness scores of the systems across a set of identified topics/queries. Design/methodology/approach – Based on the proposed approach, instead of the classic method of using a set of topic scores, the documents level scores are considered as the evaluation unit. These document scores are the defined document’s weight, which play the role of the mean average precision (MAP) score of the systems as a significance test’s statics. The experiments were conducted using the TREC 9 Web track collection. Findings – The p-values generated through the two types of significance tests, namely the Student’s t-test and Mann-Whitney show that by using the document level scores as an evaluation unit, the difference between IR systems is more significant compared with utilizing topic scores. Originality/value – Utilizing a suitable test collection is a primary prerequisite for IR systems comparative evaluation. However, in addition to reusable test collections, having an accurate statistical testing is a necessity for these evaluations. The findings of this study will assist IR researchers to evaluate their retrieval systems and algorithms more accurately.

Doppler ultrasound measurements of superior sagittal sinus blood velocity

1972 ◽  
Vol 37 (3) ◽  
pp. 312-315 ◽  
Author(s):  
Ronald Brisman ◽  
Sadek K. Hilal ◽  
Michael Tenner
Keyword(s):  
Intracranial Pressure ◽  
Superior Sagittal Sinus ◽  
Mass Effect ◽  
Blood Velocity ◽  
Doppler Measurement ◽  
Content Type ◽  
Sagittal Sinus ◽  
The Mean ◽  
Sagittal Sinus Occlusion ◽  
The Relationship

✓ Transcutaneous Doppler recordings from the patent anterior fontanel were used to measure superior sagittal sinus blood velocity (SSSV). In 15 cases it ranged from 4.5 to 18.1 cm/sec. In five of these patients with no mass effect and normal intracranial pressure, the mean SSSV was 13.6 cm/sec. An independent arteriographic measurement of SSSV was 4.5 cm/sec in a hydrocephalic patient with elevated intracranial pressure whose Doppler measurement of SSSV was 6.6 cm/ sec. The Doppler technique may be used to diagnose sagittal sinus occlusion. SSSV tended to be low when CSF pressure was elevated, but the relationship was not constant.

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