Brain perfusion following single seizures.

Purpose: The aim of this study was to assess the regional relative interictal and postictal perfusion changes in temporal and parietal lobe epilepsy.

Methods: We investigated interictal and postictal magnet resonance perfusion changes in five patients with temporal lobe epilepsy either with hippocampal sclerosis (n = 3) or without (n = 2), and in one patient with extratemporal (parietal lobe) epilepsy. T(2)*-weighted single-shot echo-planar images were acquired after bolus application of 0.

Vascular endothelial growth factor plasma levels are significantly elevated in patients with cerebral arteriovenous malformations.

Background: Since growth and de novo generation of cerebrovascular malformations were demonstrated, a strictly congenital model cannot be further supported as unique factor in the pathogenesis of cerebral arteriovenous malformations (AVMs). Vascular endothelial growth factor (VEGF) has previously been demonstrated to be highly expressed in AVMs by immunohistochemical methods. However, systemic VEGF levels have not been analysed previously.

VEGF plasma levels in non-ruptured intracranial aneurysms.

Aneurysm growth appears to be associated with an increased risk of rupture. Therefore, it may be of interest to identify mechanisms contributing to aneurysm growth. Angiogenic factors, particularly vascular endothelial growth factor (VEGF), appear to play an important role in the pathogenesis and growth of cerebrovascular malformations.

Functional magnetic resonance imaging in anesthetized patients: a relevant step toward real-time intraoperative functional neuroimaging.

Objective: The introduction of intraoperative 1.5-T magnetic resonance imaging may provide up-to-date functional information in the surgical environment. However, feasible passive paradigms that allow the examination of anesthetized patients will be a precondition for intraoperative functional magnetic resonance imaging (fMRI).

Spheno-orbital meningiomas: interdisciplinary surgical approach, resectability and long-term results.

Objective: To describe the interdisciplinary surgical approach in spheno-orbital meningiomas and to evaluate the operative results regarding resectability and functional outcome.

Patients And Methods: A series of 16 patients underwent surgical resection of spheno-orbital meningiomas followed by bony reconstruction. Four patients presented with a recurrent meningioma and had undergone surgical resection previously.

Fusion of the cerebellar hemispheres ventral to the brainstem: a rare hindbrain-related malformation.

Introduction: New variations of cerebellar malformations are being increasingly recognized using modern neuroimaging techniques. Until now only dorsal cerebellar fusion syndromes, such as the rhombencephalosynapsis and its variations have been recognized.

Case Report: We report on a 17-month-old male infant presenting with an exceptional hindbrain related malformation characterized by midline fusion of the cerebellar hemispheres ventral to the brainstem and causing symptoms due to brainstem compression.

Reconstruction of the laminar roof with miniplates for a posterior approach in intraspinal surgery: technical considerations and critical evaluation of follow-up results.

Study Design: A retrospective clinical follow-up study of patients who underwent intraspinal surgery with reconstruction of the laminar roof using titanium miniplates.

Objective: To evaluate the surgical technique of laminar roof reconstruction and to analyze follow-up results with regard to bony healing of the laminae and the development of spinal deformities.

Summary And Background Data: The reconstruction of the laminar roof was initially proposed to overcome adverse effects associated with extensive cervical laminectomy in children.

Enhanced stability of somatosensory evoked potentials attained in the median nerve by using temporal electrodes for intraoperative recording in patients in the semisitting position.

Object: Findings published in case reports indicate that monitoring of median nerve somatosensory evoked potentials (MN-SSEPs) is unreliable in patients who undergo surgery while in the semisitting position due to the occurrence of changes in the potentials that are unrelated to neurological damage. The present study was designed to test the hypothesis that in these patients MN-SSEPs are more stable when recording electrodes are placed over the temporal region.

Methods: In 30 patients who underwent surgery in the semisitting position, MN-SSEPs were recorded intraoperatively by using electrodes placed over the temporal region as well as those placed at conventional recording sites.

A novel passive functional MRI paradigm for preoperative identification of the somatosensory cortex.

The purpose of this study was to assess the feasibility of a novel passive functional magnetic resonance imaging (fMRI) paradigm for activation analysis of the somatosensory cortex utilizing a specifically designed conductor for electrical stimulation of the median and tibial nerves. Thirteen healthy volunteers underwent electrical stimulation of these nerves with defined frequencies and intensities in a block-designed fashion. Electrical stimuli were applied by two custom-designed magnetoelectrically protected coaxial leads, taking into account the technical difficulties of the application of electrical current in the fMRI environment.

Intramedullary spinal cord cavernous malformations: clinical features and risk of hemorrhage.

The aim of this study was to review the natural history of symptomatic intramedullary spinal cord (IMSC) cavernous malformations in order to analyze the underlying mechanisms leading to symptoms and determine the potential risk of lesional hemorrhage. Between January 1990 and June 2001, ten consecutive patients with IMSC cavernous malformations were treated surgically in our institution. Age ranged from 17 to 73 years (mean 34.

Presurgical evaluation of epilepsy by brain diffusion: MR-detected effects of flumazenil on the epileptogenic focus.

Purpose: After focal status epilepticus, focal alterations of the apparent diffusion coefficient (ADC) have been demonstrated in the epileptogenic zone by using diffusion-weighted magnetic resonance (MR)imaging (DWI). Effects of flumazenil on an epileptogenic focus have been demonstrated by EEG recordings, but not by functional MRI. We hypothesized that dynamic spatiotemporal alterations of brain diffusion of the epileptogenic focus after application of flumazenil will be detectable by DWI and correlate with the epileptogenic zone.

Visual evoked potentials for intraoperative neurophysiologic monitoring using total intravenous anesthesia.

Conflicting reports on the usefulness of intraoperative monitoring of visual function by means of visual evoked potentials (VEPs) initiated this study. In 32 patients without visual problems, VEPs were recorded to evaluate the reliability for intraoperative monitoring with total intravenous anesthesia. All patients underwent noncranial surgery.

Observations on intraoperative somatosensory evoked potential (SEP) monitoring in the semi-sitting position.

Background: Former case reports suggest that monitoring of median nerve somatosensory evoked potentials (M-SEP) is unreliable in patients operated in the semi-sitting position due to the occurrence of evoked potential changes unrelated to neurological damage. This study was designed to analyze these changes in greater detail and confirm that these changes are not caused by neurological damage.

Methods: M-SEP monitoring findings of 50 patients with surgery in the semi-sitting position were analyzed and compared with a group of 50 patients who underwent surgery in the supine position.

Favourable outcome after biopsy and decompression of a holocord intramedullary spinal cord astrocytoma in a newborn.

A 4-month-old male infant presented with hydrocephalus as the initial clinical symptom due to a holocord intramedullary low-grade astrocytoma. This case illustrates a possible alternative treatment to radical surgery with a benign long-term course over a 4.5 year follow-up period.

Early seizures following non-penetrating traumatic brain injury in adults: risk factors and clinical significance.

Background: In the literature dissenting data are obtained about risk factors for early post-traumatic seizures and their impact on outcome. This study was conducted to obtain more information about the clinical significance of early seizures and their possible impact on the treatment of traumatic brain injury.

Methods And Results: A consecutive series of 1868 adult patients with head injury were analysed retrospectively.

The impact of neurophysiological intraoperative monitoring on surgical decisions: a critical analysis of 423 cases.

Object: The aim of this observational clinical study was to analyze the impact of neurophysiological intraoperative monitoring (IOM) on the surgical procedure and to assess the benefits of such monitoring.

Methods: Data for 423 patients who underwent neurophysiological IOM with somatosensory evoked potentials and brainstem auditory evoked potentials during neurosurgical procedures were collected prospectively. The patients were classified into one of five groups according to the findings of IOM, the intervention following a monitoring alarm, and the patient's postoperative neurological condition.