Journal of neurosurgery
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Journal of neurosurgery · Sep 2007
Accuracy of ventriculostomy catheter placement using a head- and hand-tracked high-resolution virtual reality simulator with haptic feedback.
The purpose of this study was to evaluate the accuracy of ventriculostomy catheter placement on a head- and hand-tracked high-resolution and high-performance virtual reality and haptic technology workstation. ⋯ The accuracy of virtual ventriculostomy catheter placement achieved by participants using the simulator is comparable to the accuracy reported in a recent retrospective evaluation of free-hand ventriculostomy placements in which the mean distance from the catheter tip to the Monro foramen was 16 mm (+/- 9.6 mm).
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Journal of neurosurgery · Sep 2007
Randomized Controlled TrialReduction of intractable deafferentation pain due to spinal cord or peripheral lesion by high-frequency repetitive transcranial magnetic stimulation of the primary motor cortex.
The authors previously reported that navigation-guided repetitive transcranial magnetic stimulation (rTMS) of the precentral gyrus relieves deafferentation pain. Stimulation parameters were 10 trains of 10-second 5-Hz TMS pulses at 50-second intervals. In the present study, they used various stimulation frequencies and compared efficacies between two types of lesions. ⋯ High-frequency (5- or 10-Hz) rTMS of the precentral gyrus can reduce intractable deafferentation pain, but low-frequency stimulation (at 1 Hz) cannot. Patients with a noncerebral lesion are more suitable candidates for high-frequency rTMS of the precentral gyrus.
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Journal of neurosurgery · Sep 2007
Improved distribution of small molecules and viral vectors in the murine brain using a hollow fiber catheter.
A hollow fiber catheter was developed to improve the distribution of drugs administered via direct infusion into the central nervous system (CNS). It is a porous catheter that significantly increases the surface area of brain tissue into which a drug is infused. ⋯ The miniature hollow fiber catheter used in this study significantly increased the distribution of dye and adenoviral-mediated gene transfer in the mouse brain compared with the levels reached using a 28-gauge needle. Compared with standard single-port clinical catheters, the hollow fiber catheter has the advantage of millions of nanoscale pores to increase surface area and bulk flow in the CNS. Extending the scale of the hollow fiber catheter for the large mammalian brain shows promise in increasing the distribution and efficacy of gene therapy and drug therapy using CED.
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Journal of neurosurgery · Sep 2007
Real-time imaging of convection-enhanced delivery of viruses and virus-sized particles.
Despite recent evidence showing that convection-enhanced delivery (CED) of viruses and virus-sized particles to the central nervous system (CNS) is possible, little is known about the factors influencing distribution of these vectors with convection. To better define the delivery of viruses and virus-sized particles in the CNS, and to determine optimal parameters for infusion, the authors coinfused adeno-associated virus ([AAV], 24-nm diameter) and/or ferumoxtran-10 (24 nm) by using CED during real-time magnetic resonance (MR) imaging. ⋯ The CED method can be used to deliver AAV capsids and similar sized particles to the CNS safely and effectively over clinically relevant volumes. Moreover, real-time MR imaging of ferumoxtran-10 during infusion reveals that AAV capsids and similar sized particles have different convective delivery properties than smaller proteins and other compounds.
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Journal of neurosurgery · Sep 2007
Characteristics and distribution of somatosensory evoked potentials in the subthalamic region.
The aim of the present study is to evaluate the topographical distribution of somatosensory evoked potentials (SSEPs) in the subthalamic area, including the zona incerta (ZI). Determination of this distribution may help in the correct placement of deep brain stimulation (DBS) leads. ⋯ The results indicate that intraoperative SSEPs from DBS electrodes are helpful in refining stereotactic targets in the thalamus and subthalamic areas.