CSF protein concentration associated with ventriculoperitoneal shunt obstruction in tuberculous meningitis.

INTRODUCTION: Hydrocephalus occurs in 85% of patients with tuberculous meningitis (TBM). Ventriculoperitoneal shunt (VPS) insertion is first-line treatment for relieving increased intercranial pressure. VPS obstruction secondary to increased protein levels in cerebrospinal fluid (CSF) is a known complication. OBJECTIVE: To ascertain if there is a difference in protein levels 1) between cranial and lumbar CSF, and to quantify levels associated with VPS obstruction, and 2) obtained from lumbar puncture vs. ventricular CSF. METHOD: A 30-year retrospective analysis was undertaken. CSF protein levels were statistically analysed to determine correlation between these levels and VPS obstruction. RESULTS: Of 214 children and 376 adults who underwent VPS insertion for TBM, respectively 27.5% and 25.5% sustained blocked VPS. The mean protein level in CSF collected from the non-obstructed group was 1.76 g/l, compared to 2.94 g/l in the obstructed group. The mean CSF protein level from intraoperative ventricular vs. lumbar puncture samples in the VPS obstruction group was respectively 2.471 g/l and 2.474 g/l. CONCLUSION: Patients with increased protein levels in CSF are at a high risk of VPS blockage. In these patients, temporary measures should be employed until CSF protein levels decrease.

Preoperative three-dimensional model creation of magnetic resonance brain images as a tool to assist neurosurgical planning.

BACKGROUND: Neurosurgeons regularly plan their surgery using magnetic resonance imaging (MRI) images, which may show a clear distinction between the area to be resected and the surrounding healthy brain tissue depending on the nature of the pathology. However, this distinction is often unclear with the naked eye during the surgical intervention, and it may be difficult to infer depth and an accurate volumetric interpretation from a series of MRI image slices. OBJECTIVES: In this work, MRI data are used to create affordable patient-specific 3-dimensional (3D) scale models of the brain which clearly indicate the location and extent of a tumour relative to brain surface features and important adjacent structures. METHODS: This is achieved using custom software and rapid prototyping. In addition, functionally eloquent areas identified using functional MRI are integrated into the 3D models. RESULTS: Preliminary in vivo results are presented for 2 patients. The accuracy of the technique was estimated both theoretically and by printing a geometrical phantom, with mean dimensional errors of less than 0.5 mm observed. CONCLUSIONS: This may provide a practical and cost-effective tool which can be used for training, and during neurosurgical planning and intervention.