Publications by authors named "Brenno Caetano Troca Cabella"

5 Publications

  • Page 1 of 1

Prediction of intracranial hypertension through noninvasive intracranial pressure waveform analysis in pediatric hydrocephalus.

Childs Nerv Syst 2017 Sep 16;33(9):1517-1524. Epub 2017 Jun 16.

Division of Pediatric Neurosurgery of the Department of Surgery and Anatomy, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, 14049-900, São Paulo, Brazil.

Purpose: The purpose of this study is to evaluate a noninvasive device to assess intracranial pressure wave form in children with hydrocephalus.

Methods: A prospective and non-experimental descriptive-analytic study was performed. Fifty-six patients were enrolled in this study. They were divided in four groups: group A, children with clinically compensated hydrocephalus; B, surgically treated hydrocephalus; C, patients with acute intracranial hypertension due to hydrocephalus; and D, children without neurological disease (control). Data were collected through the installation of an extracranial deformation sensor, coupled to the children's scalp, which allowed registration of noninvasive intracranial pressure curves. Parameters obtained were analyzed: P2/P1 ratio, "classification P1 and P2 and P1 slope.

Results: P2/P1 index and "classification of P1 and P2" had a sensitivity of 80% and specificity of 100% for predicting intracranial hypertension. "P1 slope" presented no statistical difference.

Conclusion: This study showed a useful and noninvasive method for monitoring intracranial pressure, which was able to indicate the intracranial hypertension in children with hydrocephalus and, thus, should be further investigated for clinical applications.
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http://dx.doi.org/10.1007/s00381-017-3475-1DOI Listing
September 2017

Characterization of Intracranial Pressure Behavior in Chronic Epileptic Animals: A Preliminary Study.

Acta Neurochir Suppl 2016 ;122:329-33

Physics Institute of Sao Carlos, University of Sao Paulo, Sao Carlos, Brazil.

Intracranial pressure (ICP) is a major neurological parameter in animals and humans. ICP is a function of the relationship between the contents of the cranium (brain parenchyma, cerebrospinal fluid, and blood) and the volume of the skull. Increased ICP can cause serious physiological effects or even death in patients who do not quickly receive proper care, which includes ICP monitoring. Epilepsies are a set of central nervous system disorders resulting from abnormal and excessive neuronal discharges, usually associated with hypersynchronism and/or hyperexcitability. Temporal lobe epilepsy (TLE) is one of the most common forms of epilepsy and is also refractory to medication. ICP characteristics of subjects with epilepsy have not been elucidated because there are few studies associating these two important neurological factors. In this work, an invasive (ICPi) and the new minimally invasive (ICPmi) methods were used to evaluate ICP features in rats with chronic epilepsy, induced by the experimental model of pilocarpine, capable of generating the main features of human TLE in these animals.
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http://dx.doi.org/10.1007/978-3-319-22533-3_65DOI Listing
July 2017

Characterization of ICP Behavior in an Experimental Model of Hemorrhagic Stroke in Rats.

Acta Neurochir Suppl 2016 ;122:121-4

Physics Institute of Sao Carlos, University of Sao Paulo, Sao Carlos, Brazil.

Intracranial pressure (ICP) monitoring is sometimes required in clinical pictures of stroke, as extensive intraparenchymal hematomas and intracranial bleeding may severely increase ICP, which can lead to irreversible conditions, such as dementia and cognitive derangement. ICP monitoring has been accepted as a procedure for the safe diagnosis of increased ICP, and for the treatment of intracranial hypertension in some diseases. In this work, we evaluated ICP behavior during the induction of an experimental model of autologous blood injection in rats, simulating a hemorrhagic stroke. Rats were subjected to stereotactic surgery for the implantation of a unilateral cannula into the left striatal region of the brain. Autologous blood was infused into the left striatal region with an automatic microinfusion pump. ICP monitoring was performed throughout the procedure of hemorrhagic stroke induction. Analyses consisted of short-time Fourier transform for ICP before and after stroke induction and the histological processing of the animals' brains. Short-time Fourier transform analysis demonstrated oscillations in the ICP frequency components throughout time after the microinjections compared with data before them. Histological analysis revealed neuropathological changes in the striatum in all microinjected animals.
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http://dx.doi.org/10.1007/978-3-319-22533-3_24DOI Listing
July 2017

Richards-like two species population dynamics model.

Theory Biosci 2014 Dec 13;133(3-4):135-43. Epub 2014 Aug 13.

Departamento de Ciências Exatas (DEX), Universidade Federal de Lavras (UFLA), Caixa Postal 3037, Lavras, Minas Gerais, Brazil,

The two-species population dynamics model is the simplest paradigm of inter- and intra-species interaction. Here, we present a generalized Lotka-Volterra model with intraspecific competition, which retrieves as particular cases, some well-known models. The generalization parameter is related to the species habitat dimensionality and their interaction range. Contrary to standard models, the species coupling parameters are general, not restricted to non-negative values. Therefore, they may represent different ecological regimes, which are derived from the asymptotic solution stability analysis and are represented in a phase diagram. In this diagram, we have identified a forbidden region in the mutualism regime, and a survival/extinction transition with dependence on initial conditions for the competition regime. Also, we shed light on two types of predation and competition: weak, if there are species coexistence, or strong, if at least one species is extinguished.
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http://dx.doi.org/10.1007/s12064-014-0205-zDOI Listing
December 2014

Data collapse, scaling functions, and analytical solutions of generalized growth models.

Phys Rev E Stat Nonlin Soft Matter Phys 2011 Jun 2;83(6 Pt 1):061902. Epub 2011 Jun 2.

Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil.

We consider a nontrivial one-species population dynamics model with finite and infinite carrying capacities. Time-dependent intrinsic and extrinsic growth rates are considered in these models. Through the model per capita growth rate we obtain a heuristic general procedure to generate scaling functions to collapse data into a simple linear behavior even if an extrinsic growth rate is included. With this data collapse, all the models studied become independent from the parameters and initial condition. Analytical solutions are found when time-dependent coefficients are considered. These solutions allow us to perceive nontrivial transitions between species extinction and survival and to calculate the transition's critical exponents. Considering an extrinsic growth rate as a cancer treatment, we show that the relevant quantity depends not only on the intensity of the treatment, but also on when the cancerous cell growth is maximum.
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http://dx.doi.org/10.1103/PhysRevE.83.061902DOI Listing
June 2011
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