Frameless image-guided neuroendoscopy training in real simulators.

BACKGROUND: Over the last decade, neuroendoscopy has re-emerged as an interesting option in the management of intraventricular lesions in both children and adults. Nonetheless, as it has become more difficult to use cadaveric specimens in training, the development of alternative methods was vital. The aim of this study was to analyze the performance of a real simulator, in association with image-guided navigation, as a teaching tool for the training of intraventricular endoscopic procedures. METHODS: 3 real simulators were built using a special type of resin. 1 was designed to represent the abnormally enlarged ventricles, making it possible for a third ventriculostomy to be performed. The remaining 2 were designed to simulate a person's skull and brain bearing intraventricular lesions, which were placed as follows: in the foramen of Monro region, in the frontal and occipital horns of the lateral ventricles and within the third ventricle. In all models, MRI images were obtained for navigation guidance. Within the ventricles, the relevant anatomic structures and the lesions were identified through the endoscope and compared with the position given by the navigation device. The next step consisted of manipulating the lesions, using standard endoscopic techniques. RESULTS: We observed that the models were MRI compatible, easy and safe to handle. They nicely reproduced the intraventricular anatomy and brain consistence, as well as simulated intraventricular lesions. The image-based navigation was efficient in guiding the surgeon through the endoscopic procedure, allowing the selection of the best approach as well as defining the relevant surgical landmarks for each ventricular compartment. Nonetheless, as expected, navigation inaccuracies occurred. After the training sessions the surgeons felt they had gained valued experience by dealing with intraventricular lesions employing endoscopic techniques. CONCLUSION: The use of real simulators in association with image-guided navigation proved to be an effective tool in training for neuroendoscopy.

[Stereotactic implantation of depth electrodes by magnetic resonance image in epilepsy surgery]. / Implantação estereotáxica de eletrodos profundos por ressonância magnética para cirurgia de epilepsia.

We present the case of a 40-year-old woman with refractory epilepsy since aged 18, who was submitted to video-EEG monitoring with intracerebral depth electrodes. The clinical history and examination, magnetic resonance image (MRI), video-EEG and neuropsychological study did not allow the determination of the cerebral onset of epileptic seizures. Depth electrodes inserted by MRI-guided stereotaxis allowed the recording of the epileptic activity and thus showed quite accurately the area of the brain to be surgically resected. She underwent a right anterior temporal lobectomy with amygdalohippocampectomy. The immediate postoperative period was uneventful and she is without epileptic seizures after three months of follow-up. The average pre-operative free-seizure period was two weeks. To our knowledge, this is the first stereotactic surgery for insertion of depth intracerebral electrodes in epilepsy in Brazil.

Talamotomia estereotáxica para hemibalismo / Stereotactic thalamotomy for hemiballismus

O caso de um paciente com hemibalismo direito de origem traumática, refratário ao tratamento medicamentoso e tratado com sucesso por talamotomia estereotáxica é apresentado

Comparison of MRI-guided and ventriculography-based stereotactic surgery for Parkinson's disease.

Stereotactic surgery for Parkinson's disease can be performed using different neuroimaging methods. Ventriculography has been used to locate the coordinates of the structures close to the third ventricle. Although it has several potential disadvantages related to the intraventricular injection of iodine contrast, it is considered a precise method. Computed tomography and magnetic resonance imaging have been used in some centers. In order to compare their efficacy, 50 stereotactic thalamotomies for Parkinson's disease were performed using either ventriculography (VE) (25) or magnetic resonance imaging (MRI) (25). In 14 out of 25 VE procedures, computed tomography (CT-scan) was also used and showed a significant mean difference of coordinate Y and Z. The clinical results employing either VE or MRI were similar, with 80% abolition of tremor in the VE group, and 84% in the MRI group, after a follow up period of at least 3 months. Another 12% of VE and 16% of MRI group showed significant improvement of tremor. Complication rate was 4% in both groups. MRI-guided stereotactic thalamotomy in Parkinson's disease has shown good clinical results, comparable to VE-guided stereotaxis.

Thoracic intraspinal Paracoccidioidomycosis. Case report.

Intramedullary lesions caused by Paracoccidioides brasiliensis have been rarely described. Its diagnosis may be challenging and surgical approach is indicated for diagnostic and therapeutic purposes. We hereby report a case with MRI and surgical findings in a 45 year-old woman with intramedullary paracoccidioidomycosis, and make a review of other cases presented in the literature.

Cerebral cysticercosis presenting as mass lesion.

Four cases of cerebral cysticercosis that presented as brain tumor are reported. The diagnosis of these lesions was possible only after the operation. The clinical manifestations of these patients are discussed. The findings on computed tomography scanning as well as the possibilities for differential diagnosis are presented. All the patients were operated on and the diagnosis confirmed histologically. The difficulties encountered at the operations and the alternative methods for the treatment of these lesions are discussed.