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The pressure-volume function of brain elasticity

Physiological considerations and clinical applications

Frederick H. Sklar and Ilya Elashvili

T he significance of the intracranial pressure-volume relationship has been a topic of extensive clinical and laboratory investigation. The elasticity of brain, meninges, and blood vessels determines the immediate pressure response to a rapid alteration of intracranial volume. 4, 14, 26, 27 It has been suggested that quantitative consideration of the pressure-volume relationship has important clinical and therapeutic applications. 21, 24, 28 This paper reviews the relationship of intracranial pressure as a function of volume. The pressure-volume function is

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Robert P. Bentley, Spyros Sgouros, Kalyan Natarajan, M. Stephen Dover and Anthony D. Hockley

T he diagnosis and surgical correction of craniofacial anomalies often lead to orbital surgery, which initiates subsequent changes in orbital volume that would benefit from accurate, quantitative, and standardized points of reference. While investigating changes in orbital volume in children with craniosynostosis, 1 it became apparent to us that there was no accurate, reliable normal reference range of changes in orbital volume throughout childhood that could be used for a comparative study. Although CT scanning has taken a leading role as a diagnostic

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R. Carter Clement, Brendan G. Carr, Michael J. Kallan, Catherine Wolff, Patrick M. Reilly and Neil R. Malhotra

T he correlation between the volume of patients seen by a provider and outcomes has been well documented in numerous areas of health care over the last 30 years ( Table 1 ). To our knowledge, no study to date has focused on the existence of a VOR in neurotrauma care. Thus, we sought to examine the relation between case volume and survival among patients with traumatic ICH. TABLE 1: Literature survey of examples of documented VORs * VOR Authors & Year neurosurgery  aneurysmal SAH Vespa & Diringer, 2011  carotid

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Sukhraaj Basati, Bhargav Desai, Ali Alaraj, Fady Charbel and Andreas Linninger

T he dynamics of ventricular enlargement remain elusive to researchers of hydrocephalus, a disease in which CSF accumulates in the ventricular system. In normal pressure hydrocephalus, the observable CSF flow pathway remains open, yet the ventricles enlarge despite normal intracranial pressure. Continuous monitoring of the disease is difficult for patients with normal pressure hydrocephalus. There remains a lack of research related to the continuous evaluation of intraventricular volume. Thus, the importance of validating a novel volume sensor is crucial

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Computerized tomography brain scan tumor volume determinations

Sensitivity as an objective criterion of response to therapy

M. Stephen Mahaley Jr., G. Yancey Gillespie and Rita Hammett

measurements with occasional attempts to reconstruct mathematically the volume of the tumor based upon individual image areas and scan slice thickness. Finally, using a personal computer and digitizing tablet, a hand-held cursor has been used to trace a transilluminated CT image of the perimeter of an enhancing tumor. Microcomputer software converts the digitized tracings into a calculated area for each scan slice with subsequent conversion of all slices into an estimated tumor volume. Regrettably, many clinical investigative reports give little precise detail as to exactly

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Angelo L. Maset, Anthony Marmarou, John D. Ward, Sung Choi, Harry A. Lutz, Danny Brooks, Richard J. Moulton, Antonio DeSalles, J. Paul Muizelaar, Hope Turner and Harold F. Young

S ince the introduction of intracranial pressure (ICP) measurement by Guillaume and Janny 4 and Lundberg, 13 ICP monitoring has been a useful adjunct in the management of patients with brain injury. Clinical studies reported during the last decade have described the close correlation between intracranial hypertension and outcome. 2, 7, 9, 16, 17, 20–22 Other reports have emphasized the neurological deterioration resulting from secondary insult to the brain induced by depletion of volume-buffering capacity and development of high ICP. As a result of these

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Intracranial volume-pressure relationship in man

Part 1: Calculation of the pressure-volume index

Joseph Th. J. Tans and Dick C. J. Poortvliet

I ntracranial volume-pressure relationship can be studied using the volume-pressure response (VPR), defined by Miller and co-workers 8, 9 as the pressure change following 1-ml bolus additions or reductions of ventricular volume. The VPR is limited in that it provides information about only a small part of the volume-pressure curve, 15 and in that comparison of different VPR values is difficult without adding the baseline pressures at which they were evaluated. The pressure-volume index (PVI), defined by Marmarou, et al. , 6, 7 as the volume necessary to

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Ralph G. Dacey Jr.

of nearly 6000 pediatric patients in approximately 250 hospitals, treated by approximately 400 neurosurgeons. In this group, 0.5% of the patients died, 1% were transferred to another acute-care facility, and 1.7% were transferred to long-term care or rehabilitation facilities. The mortality rates associated with placement of a shunt were 0.7% for the primary procedure, and 0.4 and 0.2% for proximal and distal revisions, respectively. Their most striking finding is that the mortality rate for patients treated at high-volume hospitals and by high-volume surgeons

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Dale M. Swift and Robert A. Solomon

T reatment of aneurysmal subarachnoid hemorrhage (SAH) has increasingly included early surgery in appropriate-grade patients. 8 Intravascular volume expansion with or without induced arterial hypertension is recommended in the postoperative management of these patients in an attempt to prevent cerebral ischemia (vasospasm). 7, 8 When delayed ischemia occurs, volume expansion and arterial hypertension are the initial treatment and result in reversal of ischemic deficits in up to 70% of patients. 1, 3 Approximately 19% of patients with ruptured cerebral

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Intracranial volume-pressure relationship in man

Part 2: Clinical significance of the pressure-volume index

Joseph Th. J. Tans and Dick C. J. Poortvliet

S ince the original studies of Guillaume and Janny 2 and Lundberg, 4 many investigators have shown the usefulness of continuous monitoring of intracranial pressure (ICP) in the management of various disorders associated with intracranial hypertension. The first reports on the value of volume-pressure determinations were published in the early 1970's. 3, 11, 17 Rapid administration of fluid into the craniospinal space and measurement of the resulting pressure changes was said to be useful for identification of patients at risk for a dangerous increase in ICP