Neurosurgery
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Comparative Study
Statistical analysis of 168 bilateral subthalamic nucleus implantations by means of the probabilistic functional atlas.
Statistical analysis of patients previously operated on may improve our methods of performing subsequent surgical procedures. In this article, we introduce a method for studying the functional properties of cerebral structures from electrophysiological and neuroimaging data by using the probabilistic functional atlas (PFA). The PFA provides a spatial distribution of the clinically most effective contacts normalized to a common space. This distribution is converted into a probability function for a given point in space to be inside an effective contact. The PFA was used to analyze spatial properties of the functional subthalamic nucleus (STN), defined as the spatial volume corresponding to the distribution of effective contacts. These results may potentially be useful in planning subthalamic implantation of electrodes. ⋯ PFA-based planning may be superior to the current practice of using anatomic atlases that provide delineation of the target structure only, because it is more precise and provides a unique target point in the stereotactic space. This best stereotactic target is the point in the individualized atlas with the highest probability, meaning the highest probability of having the best target on the basis of the patients previously operated on. This best target is located in the hot STN, the size of which determines the precision of targeting. Because the size of the hot STN in comparison to the whole STN remains very small (1-2%) independent of whether or not lateral compensation is applied, target planning and execution have to be performed with high precision. The methodology presented, based on the PFA and on the functional volume, is general and can be applied to other structures and data sets. As numerous centers keep gathering large amounts of electrophysiological human and animal data, this work may facilitate opening new avenues in exploiting these data.
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Comparative Study
Comparison of magnetic tracking and optical tracking by simultaneous use of two independent frameless stereotactic systems.
The goal of this study was to compare the calculated accuracy and the true surgical accuracy of a magnetic and an optical tracking system at surgical registration and during surgery. ⋯ Magnetic referencing and tracking was found to be comparable with optical tracking both with regard to calculated and true surgical accuracy. Interference from metal objects in the magnetic field was seen rarely.
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Case Reports Comparative Study
Extradural motor cortex stimulation in advanced Parkinson's disease: the Turin experience: technical case report.
At our institution, extradural motor cortex stimulation (EMCS) has recently been applied for treating Parkinson's disease symptoms. We report our results and review the literature supporting this application of EMCS. ⋯ Unilateral EMCS relieves, at least partially, but sometimes dramatically, the whole spectrum of symptoms in advanced Parkinson's disease. L-Dopa may be reduced up to 70%. The symptoms of long-term L-dopa syndrome are usually markedly improved. The neurophysiological mechanisms involved are still under debate. Our clinical experience adds favorable data to enlarge the series of parkinsonian patients treated by EMCS.
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Comparative Study
Adjuvant gamma knife stereotactic radiosurgery at the time of tumor progression potentially improves survival for patients with glioblastoma multiforme.
Gamma knife stereotactic radiosurgery (GK-SRS) is a safe and noninvasive treatment used as adjuvant therapy for patients with glioblastoma multiforme (GBM). Several studies have yielded conflicting results in the effectiveness of radiosurgery in GBM. This study is a retrospective review of our institutional experience with GK-SRS adjuvant therapy in the treatment of GBM. ⋯ GK-SRS is a relatively safe and noninvasive procedure that conferred an improvement in overall survival of GBM patients in our retrospective study. Particularly, GK-SRS may improve overall survival when performed at the time of tumor progression.
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The present article describes a rare presentation of Type I neurofibromatosis (NFI) involving adjoining intercostal plexiform neurofibromas, as well as the novel use of thoracoscopy to guide surgical resection. This presentation highlights the manner in which NFI may affect selective regions of the body disproportionately through genetic mosaicism. ⋯ Isolated adjoining intercostal plexiform neurofibroma is a unique presentation of mosaic NFI. Because of its limited penetrance, this variant may present as a regional pain syndrome. Thoracoscopy can be used effectively to guide intercostal nerve sheath tumor resection.