Stress-Related Intracerebral Hemorrhage and the Water-Hammer Effect
2001; Lippincott Williams & Wilkins; Volume: 32; Issue: 1 Linguagem: Inglês
10.1161/01.str.32.1.275-a
ISSN1524-4628
Autores Tópico(s)Intracranial Aneurysms: Treatment and Complications
ResumoHomeStrokeVol. 32, No. 1Stress-Related Intracerebral Hemorrhage and the Water-Hammer Effect Free AccessOtherPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyRedditDiggEmail Jump toFree AccessOtherPDF/EPUBStress-Related Intracerebral Hemorrhage and the Water-Hammer Effect Johan Ahlqvist Johan AhlqvistJohan Ahlqvist Department of Physiology, University of Turku, Turku, Finland, (retired at Sibbvik, Västanfjärd, Finland) Originally published1 Jan 2001https://doi.org/10.1161/01.STR.32.1.275-aStroke. 2001;32:275–278To the Editor:Lammie et al1 described thalamic hemorrhage following emotional upset in an elderly man with old lacunar infarcts in other parts of the brain. The case supported Caplan's hypothesis that acute rises in blood pressure or cerebral blood flow may cause rupture of the small perforating arteries,1 which branch at almost right angles from the middle and posterior cerebral arteries to supply, among others, the thalamus and basal ganglia.At autopsy of cases of not only infarct but also hemorrhage, I paid attention to the frequent occurrence of potential sources of small arterial emboli in the heart or at carotid artery atheromatous plaques. That emboli might be related to hemorrhage made no sense until, as a retiree, I began to poke into the physiology2 and physics34 of flow.A water-hammer phenomenon was studied in the late 19th century.3 When flow of fluid in a pipe is stopped by sudden closure of a valve, the kinetic energy of the upstream fluid is reduced to zero very rapidly, creating a high pressure at the valve and causing a pressure wave to move upstream from it. Downstream, momentum reduces pressure. The primary waves are followed by secondary ("bouncing") ones, until the fluid comes to rest.4 The theory34 is complicated, but the brief upstream rise of pressure (Δp) at rapid closure of valves may be calculated (G.A. Öhman, personal communication, 2000) from the rather simple equation I use it to calculate a theoretical rise in pressure in the middle cerebral artery at embolic occlusion at its first major lateral bifurcation, located downstream from the orifices of its perforating arteries.A blood flow velocity (ν) of 0.36 m/s in the middle cerebral artery during anesthesia5 is low. The density (ρ) of the blood is ≈1050 kg/m3. The compressibility (K) of blood may be close to that of water, 4.8 10-10/Pa. At autopsy the internal diameter (d) of one undistended middle cerebral artery seemed to be ≈2.2 mm and its wall thickness (δ) ≈0.25 mm, both possibly underestimated. The elasticity modulus (E) of the artery may be unknown, and I use that of a rubber specimen, 5.5 106 Pa.4 If embolic occlusion is sudden, these figures result in a pressure increase (Δp) of 69 mm Hg transmitted upstream in the middle cerebral artery past the orifices of its perforating arteries.To be sudden, the time of valve closure must not exceed twice the length of the upstream pipe divided by the velocity of the pressure waves of sound in the fluid in the pipe studied, which can be calculated from the data given.4 If a middle cerebral artery ≈20 mm long is held as the upstream pipe, the occlusion, to be sudden, must occur in 1.6 ms. If 80 mm of the carotid artery is included, 8 ms is sufficient. At high blood and embolus flow velocity, occlusion of the middle cerebral artery might be sudden in a physical sense.During brain activity and emotional upset, brain blood flow velocity is higher than during anesthesia, and Δp is directly proportional to ν. The elasticity of the rubber may differ from that of the middle cerebral artery, the wall stiffness of which increases with age. In a model of the artery made of steel with a high E (2.1×1011 Pa), the other figures result in a Δp of 3788 mm Hg. Fibrinoid changes of the small perforating arteries1 may increase their fragility.The above supports the hypothesis1 that acute rises in brain blood flow velocity may trigger intracerebral hemorrhage: If combined with embolic occlusion of middle and posterior cerebral arteries downstream from perforating artery orifices, a high velocity ought to result in a local blood pressure exceeding that elsewhere in the circulation. Retrospectively, I regret that I, in cases of hemorrhagic stroke, never looked for downstream emboli. All factors in the equation can be quantified, and biophysicists might be able to test this hypothesis in models of the carotid-vertebral and cerebral arteries. The high frequency of primary hemorrhage in the brain compared with other sites might be related to the thicker and more resistant media of extracranial arteries of perforating artery diameter, but this quality of extracranial arteries of cerebral artery size may increase Δp (equation). This water-hammer mechanism is not dealt with in my textbooks of physiology. Medline gave 21 hits on "water hammer" (pulse, etc), but none dealt with primary intracerebral hemorrhage.Göran A. Öhman, PhD (Laboratory of Heat Engineering, Åbo Akademi University), gave generous help but declined authorship, citing lack of insight in blood flow in humans.Download figureDownload PowerPoint References 1 Lammie GA, Lindley R, Keir S, Wiggam MI. Stress-related primary intracerebral hemorrhage: autopsy clues to underlying mechanism. Stroke.2000; 31:1426–1428.CrossrefMedlineGoogle Scholar2 Ahlqvist J. 160 years of laminar flow: what have we learned? J Rheumatol..2000; 27:2053.MedlineGoogle Scholar3 Streeter VL. Mechanics, fluid. In: The New Encyclopaedia Britannica, Macropaedia. Chicago, Ill: Encyclopaedia Britannica Inc; 1981;11:779–793.Google Scholar4 Streeter VL. Fluid Mechanics. New York, NY: McGraw-Hill; 1962.Google Scholar5 Sakai K, Cho S, Fukusaki M, Shibasta O, Sumikawa K. The effects of propofol on human cerebral blood flow velocity and CO2 response. Anesth Analg.2000; 90:377–382.MedlineGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetailsCited By Badami M, Alizadeh P, Almasi S, Riasi A and Sadeghy K (2022) Numerical study of blood hammer phenomenon considering blood viscoelastic effects, European Journal of Mechanics - B/Fluids, 10.1016/j.euromechflu.2022.05.002, 95, (212-220), Online publication date: 1-Sep-2022. Fredon F, Baudouin M, Hardy J, Kouirira A, Jamilloux L, Taïbi A, Mabit C, Valleix D, Rouchaud A and Durand-Fontanier S (2021) An MRI study of typical anatomical variants of the anterior communicating artery complex, Surgical and Radiologic Anatomy, 10.1007/s00276-021-02782-x, 43:12, (1983-1988), Online publication date: 1-Dec-2021. Sutoko S, Atsumori H, Obata A, Funane T, Kandori A, Shimonaga K, Hama S, Yamawaki S and Tsuji T (2020) Lesions in the right Rolandic operculum are associated with self-rating affective and apathetic depressive symptoms for post-stroke patients, Scientific Reports, 10.1038/s41598-020-77136-5, 10:1, Online publication date: 1-Dec-2020. Barbosa M, Maddess T, Ahn S and Chan-Ling T (2019) Novel morphometric analysis of higher order structure of human radial peri-papillary capillaries: relevance to retinal perfusion efficiency and age, Scientific Reports, 10.1038/s41598-019-49443-z, 9:1, Online publication date: 1-Dec-2019. Mei C and Jing H (2018) Effects of thin plaque on blood hammer—An asymptotic theory, European Journal of Mechanics - B/Fluids, 10.1016/j.euromechflu.2018.01.004, 69, (62-75), Online publication date: 1-May-2018. Mei C and Jing H (2016) Pressure and wall shear stress in blood hammer – Analytical theory, Mathematical Biosciences, 10.1016/j.mbs.2016.07.007, 280, (62-70), Online publication date: 1-Oct-2016. Rossitti S Letter to the Editor: The blood-hammer effect and aneurysmal basilar artery bifurcation angles, Journal of Neurosurgery, 10.3171/2014.12.JNS142667, 122:6, (1512-1513) Graziano F, Russo V, Wang W, Khismatullin D and Ulm A (2013) 3D Computational Fluid Dynamics of a Treated Vertebrobasilar Giant Aneurysm: A Multistage Analysis, American Journal of Neuroradiology, 10.3174/ajnr.A3373, 34:7, (1387-1394), Online publication date: 1-Jul-2013. SEMYACHKINA-GLUSHKOVSKAYA O, LYCHAGOV V, BIBIKOVA O, SEMYACHKIN-GLUSHKOVSKIY I, SINDEEV S, ZINCHENKO E, KASSIM M, ALI A, LEITH A, ULANOVA M and TUCHIN V (2013) THE EXPERIMENTAL STUDY OF STRESS-RELATED PATHOLOGICAL CHANGES IN CEREBRAL VENOUS BLOOD FLOW IN NEWBORN RATS ASSESSED BY DOCT, Journal of Innovative Optical Health Sciences, 10.1142/S1793545813500235, 06:03, (1350023), Online publication date: 1-Jul-2013. January 2001Vol 32, Issue 1Article InformationMetrics Copyright © 2001 by American Heart Associationhttps://doi.org/10.1161/01.STR.32.1.275-a Originally publishedJanuary 1, 2001 PDF download Advertisement
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