New approach to localize speech relevant brain areas and hemispheric dominance using spatially filtered magnetoencephalography.

We used a current localization by spatial filtering-technique to determine primary language areas with magnetoencephalography (MEG) using a silent reading and a silent naming task. In all cases we could localize the sensory speech area (Wernicke) in the posterior part of the left superior temporal gyrus (Brodmann area 22) and the motor speech area (Broca) in the left inferior frontal gyrus (Brodmann area 44). Left hemispheric speech dominance was determined in all cases by a laterality index comparing the current source strength of the activated left side speech areas to their right side homologous.

Intraoperative magnetic resonance imaging during transsphenoidal surgery.

Object: The aim of this study was to evaluate whether intraoperative magnetic resonance (MR) imaging can increase the efficacy of transsphenoidal microsurgery, primarily in non-hormone-secreting intra- and suprasellar pituitary macroadenomas.

Methods: Intraoperative imaging was performed using a 0.2-tesla MR imager, which was located in a specially designed operating room.

A combined study of tumor-related brain lesions using MEG and proton MR spectroscopic imaging.

The purpose of this study is to localize, in cases of brain tumors, pathological magnetic brain activities and to analyze metabolic alterations in functionally abnormal lesions using magnetoencephalography (MEG) and proton magnetic resonance spectroscopic imaging (1H MRSI). The study focused on 10 healthy volunteers and seven patients with common brain tumors, namely astrocytic tumor and meningioma. In spontaneous MEG, the pathological brain activities (slow, fast waves and spikes) were localized using a single equivalent dipole model.

Intraoperative magnetic resonance imaging combined with neuronavigation: a new concept.

Objective: Intraoperative image data may be used not only to evaluate the extent of a tumor resection but also to update neuronavigation, compensating for brain shift. To date, however, intraoperative magnetic resonance imaging (MRI) can be combined only with navigation microscopes that are separated from the magnetic field, thus requiring time-consuming intraoperative patient transport. To help solve this problem, we investigated whether a new navigation microscope can be used within the fringe field of the MRI scanner.

Intraoperative imaging with open magnetic resonance imaging and neuronavigation.

The Erlangen-concept of image-guided-surgery is based on the installation of an open magnetic resonance (MR) scanner (Magnetom Open, 0.2 T, Siemens AG) in a twin operating room in combination with two neuronavigation systems (Stealth NeuroStation, Sofamor Danek, MKM Zeiss). Since March 1996 this method has been used for a total of 402 patients, among them 44 children.

[Intraoperative magnetic resonance tomography. Experiences with its use in neurosurgery].

Intraoperative magnetic resonance imaging using a 0.2 Tesla, open-configured scanner was applied in a total of 243 patients. The aim of this study was to evaluate the feasibility, clinical application, and indications of this method.

Quantification of, visualization of, and compensation for brain shift using intraoperative magnetic resonance imaging.

Objective: Modern neuronavigation systems lack spatial accuracy during ongoing surgical procedures because of increasing brain deformation, known as brain shift. Intraoperative magnetic resonance imaging was used for quantitative analysis and visualization of this phenomenon.

Methods: For a total of 64 patients, we used a 0.

Intraoperative magnetic resonance imaging in epilepsy surgery.

The aim of this study was to investigate how intraoperative magnetic resonance imaging (MRI) can help in epilepsy surgery to asses immediately whether a resection or disconnection procedure is tailored to the individual needs of a patient, thus ideally meeting the treatment plan and enhancing the efficiency of the procedure. The recently proposed concept of an individually tailored procedure with as limited tissue removal as possible would support a more conservative resection than initially advocated by many centers; such limited removal would preserve as much brain as possible that is not necessarily epileptogenic or involved in propagation of seizures. For intraoperative imaging we used a Magnetom Open 0.

Primary spinal germinoma in a patient with concomitant Klinefelter's syndrome.

It is known that patients with Klinefelter's syndrome are inclined to develop concomitant malignant tumours, as well as extragonadal germ cell tumours. The association of a primary spinal germinoma in a patient with Klinefelter's syndrome is reported for the first time, and the coincidence of elevated gonadotropin levels and oncogenesis is discussed.

Supratentorial low-grade glioma: results and prognostic factors following postoperative radiotherapy.

Background And Purpose: To assess treatment outcome and prognostic factors following postoperative external radiotherapy in 77 patients with low-grade glioma.

Patients And Methods: Between 1977 and 1996, 45 patients with astrocytoma, 14 with oligodendroglioma and 18 with mixed glioma received postoperative radiotherapy with a median total dose of 52 Gy (range, 45 to 61 Gy). Sixty-seven patients were treated immediately following surgery, 10 patients with tumor progression.

Magnetoencephalography in extratemporal epilepsy.

Epilepsy surgery candidates with extratemporal foci represent a particular diagnostic and therapeutic challenge, because of anatomic and functional features of the pertaining areas. In the last decade, novel developments in the field of electrophysiological techniques have offered new approaches to detailed localization of specific epileptic discharges as well as eloquent regions. Magnetoencephalography, in combination with neuroimaging data and simultaneously recorded EEG, yields promising results to clarify centers of epileptic activity and their relationship to structural abnormalites and functionally significant areas.

Functional neuronavigation with magnetoencephalography: outcome in 50 patients with lesions around the motor cortex.

Object: The authors conducted a study to evaluate the clinical outcome in 50 patients with lesions around the motor cortex who underwent surgery in which functional neuronavigation was performed.

Methods: The sensorimotor cortex was identified in all patients with the use of magnetoencephalography (MEG). The MEG-source localizations were superimposed onto a three-dimensional magnetic resonance image and the image data set was implemented into a neuronavigation system.

Integration of functional magnetic resonance imaging supported by magnetoencephalography in functional neuronavigation.

OBJECTIVE: In this study, the intraoperative visualization of functional data provided by functional magnetic resonance imaging (fMRI) and magnetoencephalography (MEG) leading to functional neuronavigation is demonstrated in surgery around the motor strip. METHODS: In seven patients with lesions adjacent to the central region, fMRI was performed with a 1.5-Tesla magnetic resonance system, using axial echo-planar imaging with a motor and a sensory task.

Intraoperative magnetic resonance imaging with the magnetom open scanner: concepts, neurosurgical indications, and procedures: a preliminary report.

Objective: Intraoperative magnetic resonance imaging (MRI) is now available with the General Electric MRI system for dedicated intraoperative use. Alternatively, non-dedicated MRI systems require fewer specific adaptations of instrumentation and surgical techniques. In this report, clinical experiences with such a system are presented.

Technical accuracy of a neuronavigation system measured with a high-precision mechanical micromanipulator.

Objective: This study was designed to determine and evaluate the different system-inherent sources of erroneous target localization of a light-emitting diode (LED)-based neuronavigation system (StealthStation, Stealth Technologies, Boulder, CO).

Methods: The localization accuracy was estimated by applying a high-precision mechanical micromanipulator to move and exactly locate (+/- 0.1 micron) the pointer at multiple positions in the physical three-dimensional space.

Magnetic source imaging combined with image-guided frameless stereotaxy: a new method in surgery around the motor strip.

Objective: In this study, information about the localization of the central sulcus obtained by magnetic source imaging (MSI) was intraoperatively translated to the brain, using frameless image-guided stereotaxy. In the past, the MSI results could be translated to the surgical space only by indirect methods (e.g.