Background: To drain the excess of cerebrospinal fluid in a hydrocephalus patient, a catheter is inserted into one of the brain ventricles and then connected to a valve. This so-called ventricular catheter is a standard-size, flexible tubing with a number of holes placed symmetrically around several transversal sections or "drainage segments". Three-dimensional computational dynamics shows that most of the fluid volume flows through the drainage segment closest to the valve.
View Article and Find Full Text PDFObject: A previous study by computational fluid dynamics (CFD) of the three-dimensional (3-D) flow in ventricular catheters (VC) disclosed that most of the total fluid mass flows through the catheter's most proximal holes in commercially available VC. The aim of the present study is to investigate basic flow patterns in VC prototypes.
Methods: The general procedure for the development of a CFD model calls for transforming the physical dimensions of the system to be studied into a virtual wire-frame model which provides the coordinates for the virtual space of a CFD mesh, in this case, a VC.
Introduction: Based on a landmark study by Lin et al. of the two-dimensional flow in ventricular catheters (VCs) via computational fluid dynamics (CFD), we studied in a previous paper the three-dimensional flow patterns of five commercially available VC. We found that the drainage of the cerebrospinal fluid (CSF) mostly occurs through the catheter's most proximal holes.
View Article and Find Full Text PDFObjective: We present the case of a professional jazz guitarist with temporal lobe epilepsy secondary to an arteriovenous cerebral malformation.
Case Description: The patient underwent a left temporal lobectomy in 1980. After surgery, he presented with severe retrograde amnesia and complete loss of musical interest and capabilities.
Introduction: The most common treatment for hydrocephalus remains the ventriculoperitoneal shunt. Yet, the most frequent complication is ventricular catheter obstruction, which may account for 50-80 % of newly inserted shunts. Although many factors contribute to this, the main one is related to flow characteristics of the catheter within the hydrocephalic brain.
View Article and Find Full Text PDFAn attempt was made to confirm and extend the findings of an earlier study on the rewarding properties of testosterone in male mice using conditioned place preference (CPP). Previous results had only partially demonstrated such an effect because the reinforcement depended on environmental cues such as the colour of the compartment. High individual variability was evident, suggesting that basal levels of aggressiveness may modulate such effects.
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