scholarly journals Can pulsatile CSF flow across the cerebral aqueduct cause ventriculomegaly? A prospective study of patients with communicating hydrocephalus

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
P. Holmlund ◽  
S. Qvarlander ◽  
J. Malm ◽  
A. Eklund
Keyword(s):  
Pressure Difference ◽  
Cardiac Cycle ◽  
Third Ventricle ◽  
Pressure Effects ◽  
Maximum Pressure ◽  
Cerebral Aqueduct ◽  
Communicating Hydrocephalus ◽  
Cross Sectional ◽  
Net Pressure ◽  
A Prospective Study

Abstract Background Communicating hydrocephalus is a disease where the cerebral ventricles are enlarged. It is characterized by the absence of detectable cerebrospinal fluid (CSF) outflow obstructions and often with increased CSF pulsatility measured in the cerebral aqueduct (CA). We hypothesize that the cardiac-related pulsatile flow over the CA, with fast systolic outflow and slow diastolic inflow, can generate net pressure effects that could source the ventriculomegaly in these patients. This would require a non-zero cardiac cycle averaged net pressure difference (ΔPnet) over the CA, with higher average pressure in the lateral and third ventricles. Methods We tested the hypothesis by calculating ΔPnet across the CA using computational fluid dynamics based on prospectively collected high-resolution structural (FIESTA-C, resolution 0.39 × 0.39 × 0.3 mm3) and velocimetric (2D-PCMRI, in-plane resolution 0.35 × 0.35 mm2) MRI-data from 30 patients investigated for communicating hydrocephalus. Results The ΔPnet due to CSF pulsations was non-zero for the study group (p = 0.03) with a magnitude of 0.2 ± 0.4 Pa (0.001 ± 0.003 mmHg), with higher pressure in the third ventricle. The maximum pressure difference over the cardiac cycle ΔPmax was 20.3 ± 11.8 Pa and occurred during systole. A generalized linear model verified an association between ΔPnet and CA cross-sectional area (p = 0.01) and flow asymmetry, described by the ratio of maximum inflow/outflow (p = 0.04), but not for aqueductal stroke volume (p = 0.35). Conclusions The results supported the hypothesis with respect to the direction of ΔPnet, although the magnitude was low. Thus, although the pulsations may generate a pressure difference across the CA it is likely too small to explain the ventriculomegaly in communicating hydrocephalus.

scholarly journals Theoretical Investigation of Gas Filling and Leaking in Inertial Confinement Fusion Hohlraum

2018 ◽  
Vol 10 (10) ◽  
pp. 3763 ◽  
Author(s):  
Cheng Yu ◽  
Suchen Wu ◽  
Weibo Yang
Keyword(s):  
Pressure Difference ◽  
Inertial Confinement Fusion ◽  
Polymeric Films ◽  
Lower Probability ◽  
Maximum Pressure ◽  
Inertial Confinement ◽  
Cross Sectional ◽  
Confinement Fusion ◽  
Variation Rate ◽  
Sectional Shape

The gas filling and retention of inertial confinement fusion (ICF) hohlraum is an important issue in ICF studies. In this study, a theoretical model of gas filling and leaking processes for ICF hohlraum is developed based on the unified flow theory. The effects of the fill tube size and the filling pressure on the gas filling and leaking performance are investigated. The results indicate that an increase in the variation rate of the filling/leaking pressure leads to a larger maximum pressure difference between the inside and outside of the ICF hohlraum during the filling/leaking process. The critical pressure difference of the filling process is nearly equal to that of the leaking process. Increase in fill tube diameter and decrease in its length both lead to a lower probability of the rupture of polymeric films at two ends of the hohlraum, and thus increases the security of the hohlraum. In addition, a departure in cross sectional shape of fill tube from circle to rectangle triggers an increase in pressure difference between the inside and outside of the ICF hohlraum, which raises the risk of polymeric films rupture and decreases the security of the hohlraum structure.

scholarly journals ENDOSCOPIC INTRAVENTRICULAR HEMORRHAGE REMOVAL: CLINICAL OBSERVATION AND TECHNICAL FEATURES

2019 ◽  
Vol 21 (2) ◽  
pp. 45-52 ◽  
Author(s):  
I. M. Godkov ◽  
V. G. Dashyan
Keyword(s):  
Third Ventricle ◽  
Disease Onset ◽  
Clinical Signs ◽  
Cerebral Aqueduct ◽  
Third Ventriculostomy ◽  
Communicating Hydrocephalus ◽  
Study Objective ◽  
The Third ◽  
Level Of Consciousness ◽  
Technical Features

The study objective is to describe a successful endoscopic therapy for a patient with hypertensive ventricular hemorrhage complicated by occlusive third ventricular hydrocephalus. Materials and methods. A 71-year-old patient with hypertensive hemorrhage into the III and IV ventricles, complicated by non-communicating hydrocephalus, was brought to hospital on the 1st day of the disease onset. Non-communicating hydrocephalus was accompanied by clinical signs of decompensation, depressed level of consciousness up to moderate coma (Glasgow Coma Scale score of 7). Specialists performed emergency endoscopic aspiration of blood clots from the III and IV ventricles and third ventriculostomy. Results. Endoscopically it was possible to remove the clots from the third ventricle and through the cerebral aqueduct from the fourth ventricle. Resuscitation and intensive care measures resulted in a favorable outcome: the patient was released with a moderate neurological deficit – left oculomotor nerve dysfunction. After 4 months, the patient required a ventriculoperitoneal shunt due to disresponsive form of hydrocephalus. Conclusion. Endoscopic aspiration allows removing hematomas from the third and fourth ventricles via the lateral ventricle effectively and safely.

INTERARM SYSTOLIC BLOOD PRESSURE DIFFERENCE IS ASSOCIATED WITH A HIGH PREVALENCE OF CARDIO VASCULAR DISEASES- A CROSS-SECTIONAL STUDY IN POLICE WORKER

2020 ◽  
Vol 4 (11) ◽  
Author(s):  
Somesh Raju ◽  
Rina Kumari ◽  
Sunita Tiwari ◽  
NS Verma
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Blood Sugar ◽  
Pressure Difference ◽  
Systolic Pressure ◽  
Working Environment ◽  
Vascular Events ◽  
Cross Sectional ◽  
Blood Pressure Difference ◽  
High Prevalence

Background: Interarm systolic blood pressure difference more than 10 mm of Hg is predictor of cardiovascular and metabolic risk. Despite of sufficient physical activity there is high prevalence of obesity in police personal because of stressful working environment. No studies have addressed the significance of interarm pressure difference among them. Therefore, the present study conducted to access the relation of interarm blood pressure difference with obesity in police personnel. Aims and Objective: To estimate the interarm pressure difference in police personal to see its association with their obesity. Material and Method: This cross-sectional observational study done on 245 police workers in PAC, Sitapur, India. Subjects having more than ten years of working experience were included in study. Anthropometric measurements of subject recorded by following standard protocol. Measurement of systolic pressure in both arm recorded simultaneously by mercury sphygmomanometer. Available data analyze and expressed in percentage, mean with SD and chi square test to see the significance of association. Results: According to anthropometric results of subjects 77.14 prcent subjects were having generalised obesity and 82.04 percent of subjects having abdominal obesity. 34.29 percent of subjects showed abnormally high (?10 mmHg) inter-arm systolic blood pressure difference. Both type of obesity showed positive association with blood sugar level but no association with interarm pressure difference. Conclusion: Interarm blood pressure difference is greater in individual having obesity or prolong duration of service. Such subjects are more susceptible to develop coronary artery disease or peripheral arterial disease in future. Early screening can help to detect the vascular events likely to occur in the future Keywords: Body mass index, Waist circumference, Interarm pressure difference, Random blood sugar

Evaluation of a Telephone Version for the Montreal Cognitive Assessment: Establishing a Cutoff for Normative Data From a Cross-Sectional Study

2021 ◽  
pp. 089198872110026
Author(s):  
Sivan Klil-Drori ◽  
Natalie Phillips ◽  
Alita Fernandez ◽  
Shelley Solomon ◽  
Adi J. Klil-Drori ◽  
...  
Keyword(s):  
Cognitive Assessment ◽  
Cross Sectional Study ◽  
Montreal Cognitive Assessment ◽  
Cutoff Score ◽  
Cognitive Screening ◽  
Cross Sectional ◽  
A Prospective Study ◽  
Sectional Analysis ◽  
State Examination ◽  
Normal Cognition

Objective: Compare a telephone version and full version of the Montreal Cognitive Assessment (MoCA). Methods: Cross-sectional analysis of a prospective study. A 20-point telephone version of MoCA (Tele-MoCA) was compared to the Full-MoCA and Mini Mental State Examination. Results: Total of 140 participants enrolled. Mean scores for language were significantly lower with Tele-MoCA than with Full-MoCA (P = .003). Mean Tele-MoCA scores were significantly higher for participants with over 12 years of education (P < .001). Cutoff score of 17 for the Tele-MoCA yielded good specificity (82.2%) and negative predictive value (84.4%), while sensitivity was low (18.2%). Conclusions: Remote screening of cognition with a 20-point Tele-MoCA is as specific for defining normal cognition as the Full-MoCA. This study shows that telephone evaluation is adequate for virtual cognitive screening. Our sample did not allow accurate assessment of sensitivity for Tele-MoCA in detecting MCI or dementia. Further studies with representative populations are needed to establish sensitivity.

Dynamics of the right atrio-ventricular junction in human: a spatial high-resolution study with multiphase computed tomography

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
J Jouan ◽  
I Masari ◽  
V Bliah ◽  
G Soulat ◽  
D Craiem ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Cardiac Cycle ◽  
Cardiac Computed Tomography ◽  
Reconstruction Method ◽  
Imaging Data ◽  
High Definition ◽  
Vertical Projection ◽  
Horizontal Projection ◽  
Cross Sectional ◽  
The Right

Abstract Introduction In order to improve knowledge of the tricuspid valve (TV) function and its coupling with the right atrio-ventricular junction (RAVJ) and right ventricle (RV), new four-dimensional high-definition imagery methods are mandatory (3D+t). Purpose Using an innovative reconstruction method based on multiphase cardiac computed tomography imaging (4D-MCCTI), we finely analyzed the morphological & dynamical features of tricuspid annulus (TA) and RAVJ components in order to assess new functional parameters of TV and RV functions. Methods Volume imaging data sets through time were obtained from 4D-MCCTI of 30 subjects (sex ratio 1, mean age 57±11y.) with no rhythm, valvular or ventricular abnormalities on echocardiography and implemented in a custom software for 3D semi-automated delineation of 18 points around TA perimeter. Coordinates of these points in each of the 10 time-phases within an RR interval were used to calculate specific geometrical features of TA such as 3D/2D areas, perimeters, 360°-diameters and vertical deformation. Subsequently, RV and Right Atrium (RA) inner contours were also delineated (Figure). Results TA shape was elliptical in horizontal projection with a mean eccentricity index (EcI) of 0.58±0.12; and saddle-shapped in vertical projection with a horn nearby the antero-septal commissure. This feature remained throughout the cardiac cycle but TA was more planar (minimal TA-height: 4.47±1.04 mm) and circular (minimal EcI=0.44±0.14) in mid-diastole when TA-3Darea and TA-3Dperimeter reached a maximum of 6.98±1.21 cm2/m2 and 7.41±0.91 cm, respectively. Correlation between TA-3Darea, TA-2Darea and latero-septal diameter (LSD) were R2=0.99 and R2=0.73, respectively. LSD was minimal in early-systole (18.83±3.04 mm/m2) and maximal in mid-diastole (20.04±3.05 mm/m2). Correlation of TA-3Darea with RV and RA cross-sectional areas were R2=0.82 and R2=0.71, respectively. Conversely, there was no significant correlation between TA, RV and RA concentric contractions. Conclusions Our method for 4D-MTCCI analysis has allowed confirming the shape and dynamics function of RAVJ throughout the cardiac cycle in healthy subjects, and giving new reference parameters for TV and RV evaluation. Software multiplanar view of TA Funding Acknowledgement Type of funding source: None

A comparative numerical study of the combustion performance of the syngas-fueled HCCI engine using a toroidal piston, square bowl piston, and flat piston shape at different loads

2021 ◽  
pp. 1-27
Author(s):  
Kabbir Ali ◽  
Changup Kim ◽  
Yonggyu Lee ◽  
Seungmook Oh ◽  
Ki-Seong Kim
Keyword(s):  
Numerical Study ◽  
Pressure Rise ◽  
Fuel Mixture ◽  
Combustion Efficiency ◽  
Maximum Pressure ◽  
Cross Sectional ◽  
Combustion Performance ◽  
Hcci Engine ◽  
Heat Loss Rate ◽  
Piston Bowl

Abstract This study analyzes the combustion performance of a syngas-fueled homogenous charge compression ignition (HCCI) engine using a toroidal piston, square bowl, and flat piston shape, at low, medium, and high loads, with a constant compression ratio of 17.1. In this study, the square bowl shape is optimized by reducing the piston bowl depth and squish area ratio (squish area/cylinder cross-sectional area) from (34 to 20, 10, and 2.5) %, and compared with the flat piston shape and toroidal piston shape. This HCCI engine operates under an overly lean air–fuel mixture condition for power plant usage. ANSYS Forte CFD with GRI Mech3.0 chemical kinetics is used for combustion analysis, and the calculated results are validated by the experimental results. All simulations are accomplished at maximum brake torque (MBT) by altering the air–fuel mixture temperature at IVC with a constant equivalence ratio of 0.27. This study reveals that the main factors that affect the start of combustion , maximum pressure rise rate (MPRR), combustion efficiency, and thermal efficiency by changing the piston shape are the squish flow and reverse squish flow effects. Therefore, the square bowl piston D is the optimized piston shape that offers low MPRR and high combustion performance for the syngas-fueled HCCI engine, due to the weak squish flow and low heat loss rate through the combustion chamber wall, respectively, compared to the other piston shapes of square bowl piston A, B, and C, flat piston, and toroidal (baseline) piston shape.

scholarly journals The Prevalence and Awareness of Cardiovascular Diseases Risk Factors among the Lebanese Population: A Prospective Study Comparing Urban to Rural Populations

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Iqbal Fahs ◽  
Zainab Khalife ◽  
Diana Malaeb ◽  
Mohammad Iskandarani ◽  
Pascale Salameh
Keyword(s):  
Risk Factors ◽  
Rural Areas ◽  
Overweight And Obesity ◽  
Undiagnosed Diabetes ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Undiagnosed Hypertension ◽  
Lebanese Population ◽  
Urban And Rural Areas ◽  
A Prospective Study

Introduction. CVDs are largely driven by modifiable risk factors. This study sought to determine the awareness and prevalence of the modifiable CVDs risk factors among the Lebanese population.Methods. In a cross-sectional survey, 1000 participants aged ≥ 45 years were randomly selected from pharmacies and interviewed. The data was analyzed with SPSS version 21.0 software.Results. Differences between urban and rural areas include alcohol consumption (2.8% versus 1.7%;p=0.0001), cardioprotective vegetable servings (6.1% versus 2.3%;p=0.016), sedentary hours per day (18.6% versus 15.1%;p=0.002), and hypertension (38.5% versus 25.4%;p=0.001). The prevalence of overweight and obesity (77.3% versus 75.2%;p=0.468), smoking (39.3% versus 43.3%;p=0.232), diabetes (25.4% versus 21.4%;p=0.173), and dyslipidemia (25 versus 21.2%) was reported. Measurements revealed 19.3% of undiagnosed hypertension (12.4% versus 22.4%,p=0.001), 61.7% of hypertension (59.8% versus 62.6%;p=0.203), and 7.9% of undiagnosed diabetes (6.6% versus 8.6%;p=0.323). The declared awareness of CVDs risk factors was highest for smoking (91.5% versus 89.7%;p=0.339) and lowest for diabetes (54.4 versus 55.7%;p=0.692).Conclusion. This study has shown a high prevalence of modifiable CVDs risk factors in the Lebanese population ≥ 45 years, among which hypertension is the most prominent.

Neuroendoscopic Aspiration of Blood Clots in the Cerebral Aqueduct and Third Ventricle During Posterior Fossa Surgery in the Prone Position

2018 ◽  
Vol 17 (2) ◽  
pp. 143-148 ◽  
Author(s):  
Alberto Feletti ◽  
Riccardo Stanzani ◽  
Matteo Alicandri-Ciufelli ◽  
Giuliano Giliberto ◽  
Matteo Martinoni ◽  
...  
Keyword(s):  
Prone Position ◽  
Posterior Fossa ◽  
Fourth Ventricle ◽  
Blood Clot ◽  
Third Ventricle ◽  
Cerebral Aqueduct ◽  
Posterior Fossa Surgery ◽  
The Third ◽  
Blood Clots ◽  
Surgical Field

AbstractBACKGROUNDDuring surgery in the posterior fossa in the prone position, blood can sometimes fill the surgical field, due both to the less efficient venous drainage compared to the sitting position and the horizontally positioned surgical field itself. In some cases, blood clots can wedge into the cerebral aqueduct and the third ventricle, and potentially cause acute hydrocephalus during the postoperative course.OBJECTIVETo illustrate a technique that can be used in these cases: the use of a flexible scope introduced through the opened roof of the fourth ventricle with a freehand technique allows the navigation of the fourth ventricle, the cerebral aqueduct, and the third ventricle in order to explore the cerebrospinal fluid pathways and eventually aspirate blood clots and surgical debris.METHODSWe report on one patient affected by an ependymoma of the fourth ventricle, for whom we used a flexible neuroendoscope to explore and clear blood clots from the cerebral aqueduct and the third ventricle after the resection of the tumor in the prone position. Blood is aspirated with a syringe using the working channel of the scope as a sucker.RESULTSA large blood clot that was lying on the roof of the third ventricle was aspirated, setting the ventricle completely free. Other clots were aspirated from the right foramen of Monro and from the optic recess.CONCLUSIONWe describe this novel technique, which represents a safe and efficient way to clear the surgical field at the end of posterior fossa surgery in the prone position. The unusual endoscopic visual perspective and instrument maneuvers are easily handled with proper neuroendoscopic training.

scholarly journals Prediction of Mental Illness Using Indian Astrology: Cross-Sectional Findings from a Prospective Study

2018 ◽  
Vol 32 (3) ◽  
pp. 555-578
Author(s):  
Rajeshkrishna Bhandary ◽  
Podila Satya Sharma ◽  
Hema Tharoor
Keyword(s):  
Mental Illness ◽  
Prospective Study ◽  
Cross Sectional ◽  
A Prospective Study

scholarly journals A prospective study of spectrum of pulmonary tuberculosis in HIV sero positive patients

2021 ◽  
Vol 8 (12) ◽  
pp. 1856
Author(s):  
Ganedi Seshu Kumari
Keyword(s):  
Miliary Tuberculosis ◽  
Cross Sectional Study ◽  
Common Finding ◽  
Hiv Positive ◽  
Cd4 Cells ◽  
Cross Sectional ◽  
Pulmonary Tb ◽  
Male Predominance ◽  
Chest X Ray ◽  
A Prospective Study

Background: Tuberculosis is the leading cause of death in India contributing to 30% of total global burden. Approximately 0.5 million people dies of TB annually and 5% of the incident TB cases in India have HIV. So it is important to understand the effect of tuberculosis and HIV on each other. HIV epidemics have leads to increased number of tuberculosis cases with various presentations.Methods: It is an observational cross-sectional study of patients with HIV positive and pulmonary TB. Patients were investigated for HIV positivity by HIV coomb's test, if positive confirmed by capillaries and tridot method. Some patients, who are diagnosed as having pulmonary Koch, are sent for HIV testing. CD4 cells count as tested in all patients with HIV positive and severity of pulmonary TB and relation with CD count is studied in all patients.Results: In chest x-ray of patients we have observed that upper zone infiltration was found in 10 (16.67%) patients, mid and lower zone infiltration was found in 19 (31.67%) patients, bilateral infiltration and miliary tuberculosis was found in 22 (36.67%). We have found that 9 (15%) patients were presented with fibro cavitary lesion.Conclusions: From present study we can conclude that tuberculosis and HIV is common between 3rd and 5th decade of life with male predominance. It was more common in daily labourer and BMI was 18.22±3.21 kg/m2. Fever, weight loss and cough was most common presentation and present in more than 90% patients pallor and lymphadenopathy was common finding and present in more than 50% patients.

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