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Sincomb S, Moral-Pulido F, Campos O, Martínez-Bazán C, Haughton V, Sánchez A. An in vitro experimental investigation of oscillatory flow in the cerebral aqueduct. EUROPEAN JOURNAL OF MECHANICS. B, FLUIDS 2024; 105:180-191. [PMID: 38770034 PMCID: PMC11105671 DOI: 10.1016/j.euromechflu.2024.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
This in vitro study aims at clarifying the relation between the oscillatory flow of cerebrospinal fluid (CSF) in the cerebral aqueduct, a narrow conduit connecting the third and fourth ventricles, and the corresponding interventricular pressure difference. Dimensional analysis is used in designing an anatomically correct scaled model of the aqueduct flow, with physical similarity maintained by adjusting the flow frequency and the properties of the working fluid. The time-varying pressure difference across the aqueduct corresponding to a given oscillatory flow rate is measured in parametric ranges covering the range of flow conditions commonly encountered in healthy subjects. Parametric dependences are delineated for the time-averaged pressure fluctuations and for the phase lag between the transaqueductal pressure difference and the flow rate, both having clinical relevance. The results are validated through comparisons with predictions obtained with a previously derived computational model. The parametric quantification in this study enables the derivation of a simple formula for the relation between the transaqueductal pressure and the stroke volume. This relationship can be useful in the quantification of transmantle pressure differences based on non-invasive magnetic-resonance-velocimetry measurements of aqueduct flow for investigation of CSF-related disorders.
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Affiliation(s)
- S. Sincomb
- Department of Aerospace and Mechanical Engineering, University of California, San Diego, La Jolla, 92093-0411, CA, USA
| | - F. Moral-Pulido
- Department of Mechanical and Mining Engineering, University of Jaen, Jaen, 23071, Spain
- Andalusian Institute for Earth System Research, University of Jaen, Jaen, 23071, Spain
| | - O. Campos
- Department of Aerospace and Mechanical Engineering, University of California, San Diego, La Jolla, 92093-0411, CA, USA
| | - C. Martínez-Bazán
- Department of Mechanics of Structures and Hydraulic Engineering, University of Granada, Granada, 18001, Spain
- Andalusian Institute for Earth System Research, University of Granada, Granada, 18006, Spain
| | - V. Haughton
- School of Medicine and Public Health, University of Wisconsin-Madison, Madison, 53706, WI, USA
| | - A.L. Sánchez
- Department of Aerospace and Mechanical Engineering, University of California, San Diego, La Jolla, 92093-0411, CA, USA
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Abenavoli A, Pisa S, Maggiani A. A Pilot Study of Jugular Compression (Queckenstedt maneuver) for Cranial Movement Perception. J Osteopath Med 2021; 120:647-654. [PMID: 32897302 DOI: 10.7556/jaoa.2020.119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Context Osteopathy in the cranial field (OCF) is among the most controversial topics of osteopathic practice. The mechanism by which cranial movement (CM) occurs is poorly understood, but includes speculation that intracranial pressure can generate a movement of the cranial bones. If this model is valid, an increase in intracranial pressure produced by bilateral compression of internal jugular veins, or the Queckenstedt maneuver (Q-test), should be detectable. Objective To determine whether osteopaths can perceive a palpable change in CM when the Q-test is applied. Methods Blindfolded osteopaths experienced in OCF evaluated the CM of volunteers as a trained clinician applied the Q-test. The osteopaths reported any change in CM amplitude during 3 different 1-minute periods. The total number of variations perceived in each period (PV) by all osteopaths on all volunteers was analyzed. The Kruskal Wallis test was used to evaluate the differences between the test periods. The Mann-Whitney test was used for a pairwise comparison. Statistical significance was set at P≤.05. Results Eight osteopaths participated in this study and evaluated the CM of 6 volunteers. A Kruskal-Wallis test of the PV between monitoring periods revealed a statistically significant difference (P<.001). A Mann-Whitney Test showed there was a significant increase in PV between the compression period and the 2 other monitoring periods (base P=.003 and expectation P=.009). Conclusion Osteopaths could detect a change in the amplitude of CM after the Q-test was applied. Although this was a small-scale pilot study, our data represent a starting point for understanding whether an intracranial or an extracranial mechanism is responsible for the CM.
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Sincomb SJ, Coenen W, Criado-Hidalgo E, Wei K, King K, Borzage M, Haughton V, Sánchez AL, Lasheras JC. Transmantle Pressure Computed from MR Imaging Measurements of Aqueduct Flow and Dimensions. AJNR Am J Neuroradiol 2021; 42:1815-1821. [PMID: 34385144 DOI: 10.3174/ajnr.a7246] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 05/27/2021] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Measuring transmantle pressure, the instantaneous pressure difference between the lateral ventricles and the cranial subarachnoid space, by intracranial pressure sensors has limitations. The aim of this study was to compute transmantle pressure noninvasively with a novel nondimensional fluid mechanics model in volunteers and to identify differences related to age and aqueductal dimensions. MATERIALS AND METHODS Brain MR images including cardiac-gated 2D phase-contrast MR imaging and fast-spoiled gradient recalled imaging were obtained in 77 volunteers ranging in age from 25-92 years of age. Transmantle pressure was computed during the cardiac cycle with a fluid mechanics model from the measured aqueductal flow rate, stroke volume, aqueductal length and cross-sectional area, and heart rate. Peak pressures during caudal and rostral aqueductal flow were tabulated. The computed transmantle pressure, aqueductal dimensions, and stroke volume were estimated, and the differences due to sex and age were calculated and tested for significance. RESULTS Peak transmantle pressure was calculated with the nondimensional averaged 14.4 (SD, 6.5) Pa during caudal flow and 6.9 (SD, 2.8) Pa during rostral flow. It did not differ significantly between men and women or correlate significantly with heart rate. Peak transmantle pressure increased with age and correlated with aqueductal dimensions and stroke volume. CONCLUSIONS The nondimensional fluid mechanics model for computing transmantle pressure detected changes in pressure related to age and aqueductal dimensions. This novel methodology can be easily used to investigate the clinical relevance of the transmantle pressure in normal pressure hydrocephalus, pediatric communicating hydrocephalus, and other CSF disorders.
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Affiliation(s)
- S J Sincomb
- From the Department of Mechanical and Aerospace Engineering (S.J.S., E.C.-H., A.L.S., J.C.L.), University of California San Diego, La Jolla, California
| | - W Coenen
- Departamento de Ingeniería Térmica y de Fluidos (W.C.), Grupo de Mecánica de Fluidos, Universidad Carlos III de Madrid, Leganés (Madrid), Spain
| | - E Criado-Hidalgo
- From the Department of Mechanical and Aerospace Engineering (S.J.S., E.C.-H., A.L.S., J.C.L.), University of California San Diego, La Jolla, California
| | - K Wei
- MRI Center (K.W.), Huntington Medical Research Institutes, Pasadena, California
| | - K King
- Barrow Neurological Institute (K.K.), Phoenix, Arizona
| | - M Borzage
- Fetal and Neonatal Institute (M.B.), Division of Neonatology, Children's Hospital Los Angeles, Los Angeles, California.,Department of Pediatrics (M.B.), Keck School of Medicine, University of Southern California, Los Angeles, California
| | - V Haughton
- Department of Radiology (V.H.), School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin
| | - A L Sánchez
- From the Department of Mechanical and Aerospace Engineering (S.J.S., E.C.-H., A.L.S., J.C.L.), University of California San Diego, La Jolla, California
| | - J C Lasheras
- From the Department of Mechanical and Aerospace Engineering (S.J.S., E.C.-H., A.L.S., J.C.L.), University of California San Diego, La Jolla, California
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Holmlund P, Qvarlander S, Malm J, Eklund A. Can pulsatile CSF flow across the cerebral aqueduct cause ventriculomegaly? A prospective study of patients with communicating hydrocephalus. Fluids Barriers CNS 2019; 16:40. [PMID: 31865917 PMCID: PMC6927212 DOI: 10.1186/s12987-019-0159-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 12/05/2019] [Indexed: 11/26/2022] Open
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.
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Affiliation(s)
- P Holmlund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.
| | - S Qvarlander
- Department of Radiation Sciences, Umeå University, Umeå, Sweden
| | - J Malm
- Department of Pharmacology and Clinical Neuroscience, Umeå University, Umeå, Sweden
| | - A Eklund
- Department of Radiation Sciences, Umeå University, Umeå, Sweden.,Umeå Centre for Functional Brain Imaging, Umeå University, Umeå, Sweden
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Vinje V, Ringstad G, Lindstrøm EK, Valnes LM, Rognes ME, Eide PK, Mardal KA. Respiratory influence on cerebrospinal fluid flow - a computational study based on long-term intracranial pressure measurements. Sci Rep 2019; 9:9732. [PMID: 31278278 PMCID: PMC6611841 DOI: 10.1038/s41598-019-46055-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 06/17/2019] [Indexed: 11/27/2022] Open
Abstract
Current theories suggest that waste solutes are cleared from the brain via cerebrospinal fluid (CSF) flow, driven by pressure pulsations of possibly both cardiac and respiratory origin. In this study, we explored the importance of respiratory versus cardiac pressure gradients for CSF flow within one of the main conduits of the brain, the cerebral aqueduct. We obtained overnight intracranial pressure measurements from two different locations in 10 idiopathic normal pressure hydrocephalus (iNPH) patients. The resulting pressure gradients were analyzed with respect to cardiac and respiratory frequencies and amplitudes (182,000 cardiac and 48,000 respiratory cycles). Pressure gradients were used to compute CSF flow in simplified and patient-specific models of the aqueduct. The average ratio between cardiac over respiratory flow volume was 0.21 ± 0.09, even though the corresponding ratio between the pressure gradient amplitudes was 2.85 ± 1.06. The cardiac cycle was 0.25 ± 0.04 times the length of the respiratory cycle, allowing the respiratory pressure gradient to build considerable momentum despite its small magnitude. No significant differences in pressure gradient pulsations were found in the sleeping versus awake state. Pressure gradients underlying CSF flow in the cerebral aqueduct are dominated by cardiac pulsations, but induce CSF flow volumes dominated by respiration.
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Affiliation(s)
- Vegard Vinje
- Department of Scientific Computing and Numerical Analysis, Simula Research Laboratory, 1325, Lysaker, Norway.
| | - Geir Ringstad
- Department of Radiology and Nuclear Medicine, Oslo University Hospital - Rikshospitalet, 0372, Oslo, Norway
| | | | | | - Marie E Rognes
- Department of Scientific Computing and Numerical Analysis, Simula Research Laboratory, 1325, Lysaker, Norway
| | - Per Kristian Eide
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, 0315, Oslo, Norway.,Department of Neurosurgery, Oslo University Hospital - Rikshospitalet, 0372, Oslo, Norway
| | - Kent-Andre Mardal
- Department of Scientific Computing and Numerical Analysis, Simula Research Laboratory, 1325, Lysaker, Norway.,Department of Mathematics, University of Oslo, 0315, Oslo, Norway
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Estimation of the lateral ventricles volumes from a 2D image and its relationship with cerebrospinal fluid flow. BIOMED RESEARCH INTERNATIONAL 2013; 2013:215989. [PMID: 24151585 PMCID: PMC3787552 DOI: 10.1155/2013/215989] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 08/12/2013] [Indexed: 11/30/2022]
Abstract
Purpose. This work suggests a fast estimation method of the lateral ventricles volume from a 2D image and then determines if this volume is correlated with the cerebrospinal fluid flow at the aqueductal and cerebral levels in neurodegenerative diseases. Materials and Methods. FForty-five elderly patients suffering from Alzheimer's disease (19), normal pressure hydrocephalus (13), and vascular dementia (13) were involved and underwent anatomical and phase contrast MRI scans. Lateral ventricles and stroke volumes were assessed on anatomical and phase contrast scans, respectively. A common reference plane was used to calculate the lateral ventricles' area on 2D images. Results. The largest volumes were observed in hydrocephalus patients. The linear regression between volumes and areas was computed, and a strong positive correlation was detected (R2 = 0.9). A derived equation was determined to represent the volumes for any given area. On the other hand, no significant correlations were detected between ventricles and stroke volumes (R2 ≤ 0.15). Conclusion. Lateral ventricles volumes are significantly proportional to the 2D reference section area and could be used for patients' follow-up even if 3D images are unavailable. The cerebrospinal fluid fluctuations in brain disorders may depend on many physiological parameters other than the ventricular morphology.
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