Articles from Journal of neurosurgery

Journal of neurosurgery · Aug 2003

Computational and experimental study of proximal flow in ventricular catheters. Technical note.

The treatment of hydrocephalus with shunt insertion is fraught with high failure rates. Evidence indicates that the proximal holes in a catheter are the primary sites of blockage. The authors have studied ventricular catheter designs by using computational fluid dynamics (CFD), two-dimensional water table experiments, and a three-dimensional (3D) automated testing apparatus together with an actual catheter. ⋯ Given this finding, new designs that incorporated varying hole pattern distributions and size dimensions of the ventricular catheter were conceived and tested using two models. These changes in the geometrical features significantly changed the entering mass flow rate distribution. In conclusion, new designs in proximal ventricular catheters with variable hole diameters along the catheter tip allowed fluid to enter the catheter more uniformly along its length, thereby reducing the probability of its becoming occluded.

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Journal of neurosurgery · Aug 2003

Preoperative correlation of intraoperative cortical mapping with magnetic resonance imaging landmarks to predict localization of the Broca area.

Broca identified the posterior third of the inferior frontal gyrus as a locus essential for the production of fluent speech. The authors have conducted this retrospective analysis in an attempt to find readily identifiable landmarks on magnetic resonance (MR) imaging that correspond to intraoperative cortical stimulation-induced speech arrest. These landmarks demonstrate novel structural-functional relationships that can be used preoperatively to predict the location of the Broca area. ⋯ The results indicate a correlation between the structure of the frontal operculum as seen on MR imaging and the functional localization of speech arrest in the dominant hemisphere. Additionally, sulcal landmarks that can be used preoperatively to predict the location of the Broca area within the inferior frontal gyrus are described based on the patient population. This information will allow the surgeon to determine if an awake craniotomy is necessary to identify the Broca area when planning a surgical procedure near the dominant frontal operculum.

Spontaneous fusiform middle cerebral artery aneurysms: characteristics and a proposed mechanism of formation.

The goal of this study was to identify the origins of spontaneous fusiform middle cerebral artery (MCA) aneurysms. ⋯ Analysis of results after various treatments indicates that for symptomatic lesions, therapies that reverse intraaneurysmal blood flow and augment distal cerebral perfusion are associated with better outcomes than other strategies, including conservative management. Based on the spectrum of clinical, pathological, neuroimaging, and intraoperative findings, dissection is proposed as the underlying cause of these lesions.