Cranial Tumor Surgical Outcomes at a High-Volume Academic Referral Center.

Objective: To determine adverse event rates for adult cranial neuro-oncologic surgeries performed at a high-volume quaternary academic center and assess the impact of resident participation on perioperative complication rates.

Patients And Methods: All adult patients undergoing neurosurgical intervention for an intracranial neoplastic lesion between January 1, 2009, and December 31, 2013, were included. Cases were categorized as biopsy, extra-axial/skull base, intra-axial, or transsphenoidal.

MRI-Guided Stereotactic System for Delivery of Intraspinal Microstimulation.

Study Design: Laboratory/animal-based proof of principle study.

Objective: To validate the accuracy of a magnetic resonance imaging (MRI)-guided stereotactic system for intraspinal electrode targeting and demonstrate the feasibility of such a system for controlling implantation of intraspinal electrodes.

Summary Of Background Data: Intraspinal microstimulation (ISMS) is an emerging preclinical therapy, which has shown promise for the restoration of motor function following spinal cord injury.

Anterior nuclear deep brain stimulation guided by concordant hippocampal recording.

Object: Anterior nuclear (AN) stimulation has been reported to reduce the frequency of seizures, in some cases dramatically; however, it has not been approved by the US Food and Drug Administration. The anterior nucleus is difficult to target because of its sequestered location, partially surrounded by the ventricle. It has traditionally been targeted by using transventricular or lateral transcortical routes.

Unilateral deep brain stimulation of the subthalamic nucleus for Parkinson disease.

Object: The object of this study was to assess the results of unilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) for management of advanced Parkinson disease (PD).

Methods: A clinical series of 24 patients (mean age 71 years, range 56-80 years) with medically intractable PD, who were undergoing unilateral magnetic resonance imaging-targeted, electrophysiologically guided STN DBS, completed a battery of qualitative and quantitative outcome measures preoperatively (baseline) and postoperatively, using a modified Core Assessment Program for Intracerebral Transplantations protocol. The mean follow-up period was 9 months.

Computer-assisted image-guided surgery using the Regulus Navigator.

The term "frameless image-guided surgery" has become as well-known to surgeons as computerized tomography or operating room microscope over the past several years. The technologies behind this new surgery option include robotic arms, infra-red camera arrays (1D and 2D), ultrasound, robotic microscopes and magnetic field digitizers. The authors have shown the magnetic field technology incorporated in the Regulus Navigator to be a viable, accurate surgeon's tool by first integrating a conventional framed device and magnetic field frameless device, then advancing to the frameless device alone.

Unilateral pallidotomy for Parkinson's disease: comparison of outcome in younger versus elderly patients.

We studied the effects of medial pallidotomy in the first 20 consecutive patients with Parkinson's disease (PD) undergoing this MRI/electrophysiologically guided procedure at our institution. The mean age of patients was 65.5 years (median 66.

Pallidal targeting with the COMPASS system.

The authors describe their initial experience with the new pallidotomy targeting software for the COMPASS system. As COMPASS permits window and contrast settings to be changed at any time, multiple imaging modalities can be employed for targeting. This feature allowed the incorporation of fast-spin echo/inversion recovery (FSE/IR) magnetic resonance images (MRI) into the planning protocol.

The interactive use of magnetoencephalography in stereotactic image-guided neurosurgery.

Objective: To expand the use of magnetoencephalography (MEG) functional mapping in the operating room as well as preoperatively, a method of integrating the MEG sensorimotor mapping information into a stereotactic database, using computed tomographic scans, magnetic resonance imaging scans, and digital angiography, was developed. The combination of functional mapping and the stereotactic technique allows simultaneous viewing of the spatial relationship between the MEG-derived functional mapping, the radiological/structural anatomic characteristics, and the pathological abnormality.

Methods: MEG data were collected using a MAGNES II Biomagnetometer and were incorporated into the COMPASS frame-based and REGULUS frameless stereotactic systems.

Quantitative analysis of a noninvasive stereotactic image registration technique.

Our group has developed and tested a noninvasive image registration technique that does not require a special imaging study following the application of a head frame or radiological markers on the patient. This registration method involves performing automatic alignment between segmented scalp reconstructions from CT or MRI fitted with are surfaces traced with the Regulus Navigator. This paper will present a quantitative analysis of this technique compared to other stereotactic and image-guided registration techniques.

Stereotactic ventrolateral thalamotomy: is ventriculography necessary?

In the computed tomography/magnetic resonance imaging (CT/MRI) era, the need for ventriculography to perform ventrolateral thalamotomy accurately has been debated. We retrospectively compared CT/MRI-derived coordinates for ventrolateral thalamotomy with the final lesion coordinates that were determined by ventriculography and microelectrode recording in 74 thalamotomies performed from 1984 to 1994. The median three-dimensional distance between the CT/MRI-derived loci and the ventriculography/microelectrode loci was 4.

A stereotactic magnetic field digitizer.

A three-dimensional magnetic field digitizer has been interfaced the COMPASS Stereotactic System to act as a measuring device aiding in computer-assisted volumetric procedures. Reference points on the stereotactic headholder are used to create a transformation matrix to convert the digitizer coordinates to stereotactic coordinates, allowing the location of the stylus to be displayed on CT and reconstructed tumor volume images to maintain the surgeon's orientation. This technology is an adjunct to and employs treatment planning software of the system to calculate a target and determine a safe trajectory to a lesion.

Three-dimensional display in the evaluation and performance of neurosurgery without a stereotactic frame: more than a pretty picture?

Display of three-dimensionally rendered images derived from radiological data sets is often suggested to be useful for surgical and radiation treatment planning in neurosurgery. Nevertheless, physicians will often note (off the record) that these rendered images are 'just a pretty picture' and are not clinically useful. This paper will discuss our three-dimensional rendering and quantitative analysis software and its primary use in evaluating and utilizing frameless stereotactic methodologies.

Computer and imaging technology's impact on stereotactic neurosurgery. A 1987-1991 update.

Many improvements in computer and imaging technology have occurred since the last meeting of the American Society for Stereotactic and Functional Neurosurgery in 1987. These improvements are leading to a much wider acceptance of computerization and computer-assisted surgical procedures in the stereotactic neurosurgery field. This paper surveys the current fields of computer and imaging technology and its relationship and impact on the field of stereotactic neurosurgery during the period of 1987-1991.

A new multimodality correlative imaging technique for VOP/VIM (VL) thalamotomy procedures.

This paper describes our experience at Mayo Clinic with a new technique for planning ventro-oralis posterior (VOP) ventral intermediate (ventrolateral) VIM (VL) thalamotomy procedures for selected patients with medically intractable tremor. This new method employs a multimodality correlative imaging technique for determining the lesion target point on MR images. At surgery, stereotactic frame settings for the final lesion target were ultimately determined by stereotactic ventriculography modified by neurophysiological recording.

Evolution of contemporary instrumentation for computer-assisted stereotactic surgery.

This article discusses the evolution of our stereotactic system which evolved from the commercially available Todd-Wells stereotactic instrument. The Todd-Wells frame was originally designed for radiographically based, functional neurosurgical procedures. We modified it for computed tomography compatibility and later devised localization systems for magnetic resonance imaging and digital angiography.

The stereotaxic retractor in computer-assisted stereotaxic microsurgery. Technical note.

The authors describe a cylindrical retractor that is attached to a standard stereotaxic frame. This retractor provides a route for stereotaxic procedures and exposure of and a reference structure for the computer-assisted removal of deep-seated intracranial lesions defined stereotaxically by computerized tomography and magnetic resonance imaging.

Cerebral astrocytomas: histopathologic correlation of MR and CT contrast enhancement with stereotactic biopsy.

Gadolinium-labeled diethylenetriaminepentaacetic acid was used as a contrast agent for stereotactic magnetic resonance (MR) imaging in six selected patients with brain tumors who underwent stereotactic biopsy. Regions of contrast enhancement demonstrated by computed tomography (CT) and MR imaging in four of the six patients correlated with areas of malignant neovascularity and endothelial proliferation within solid tumor. Radiation necrosis produced contrast enhancement indistinguishable from that of recurrent neoplasm.

Results of computed tomography-based computer-assisted stereotactic resection of metastatic intracranial tumors.

Forty-four patients underwent 45 computer-assisted stereotactic resections of intracranial metastases from various centrally located and deep-seated regions using methods described in this report and elsewhere. Gross total removal was achieved in all cases. There was no postoperative mortality (within 30 days).

Computer-assisted stereotactic biopsy of intracranial lesions in pediatric patients.

A computer-assisted stereotactic biopsy technique has been used in 30 patient (ages 5 months to 16 years) with intracranial lesions (supratentorial in 23 and infratentorial in 7). The computer program integrates stereotactically gathered imaging data and permits preoperative planning of a biopsy trajectory. Diagnostic tissue was obtained in 27 cases.

Computer-assisted stereotactic ventralis lateralis thalamotomy with microelectrode recording control in patients with Parkinson's disease.

Stereotactic ventralis lateralis thalamotomy can be performed in selected patients with medically intractable parkinsonian tremor and rigidity. New technology, including computed tomography-based stereotaxis and microelectrode recording techniques, provides a data base for precise localization of thalamic lesions tailored to each patient and thus reduces the risk associated with such a procedure. At our institution, 12 patients with medically intractable parkinsonian tremor have undergone this procedure; all experienced alleviation or cessation of the tremor and no permanent disabling neurologic sequelae.

Stereotactic histologic correlations of computed tomography- and magnetic resonance imaging-defined abnormalities in patients with glial neoplasms.

In 39 patients who harbored previously untreated astrocytomas (21 patients), oligoastrocytomas (9 patients), or oligodendrogliomas (9 patients), computed tomographic (CT) and magnetic resonance imaging (MRI) findings were correlated with stereotactic serial biopsy findings. The 39 patients were classified as having one of three types of tumor: type I (1 patient), which consisted only of circumscribed tumor tissue; type II (26 patients), which consisted of tumor tissue and isolated tumor cells; or type III (11 patients), which consisted of intact parenchyma infiltrated by isolated tumor cells. (In one patient, the biopsy sampling was inadequate for determining the type of tumor.

Imaging-based stereotaxic serial biopsies in untreated intracranial glial neoplasms.

Forty patients with previously untreated intracranial glial neoplasms underwent stereotaxic serial biopsies assisted by computerized tomography (CT) and magnetic resonance imaging (MRI). Tumor volumes defined by computer reconstruction of contrast enhancement and low-attenuation boundaries on CT and T1 and T2 prolongation on MRI revealed that tumor volumes defined by T2-weighted MRI scans were larger than those defined by low-attenuation or contrast enhancement on CT scans. Histological analysis of 195 biopsy specimens obtained from various locations within the volumes defined by CT and MRI revealed that: contrast enhancement most often corresponded to tumor tissue without intervening parenchyma; hypodensity corresponded to parenchyma infiltrated by isolated tumor cells or in some instances to tumor tissue in low-grade gliomas or to simple edema; and isolated tumor cell infiltration extended at least as far as T2 prolongation on magnetic resonance images.

Magnetic resonance imaging-based computer-assisted stereotactic resection of the hippocampus and amygdala in patients with temporal lobe epilepsy.

In patients with medically intractable complex partial seizures of temporal lobe origin, stereotactic amygdalohippocampectomy can now provide excellent results. Target structures can be accurately identified and completely resected with use of a carbon dioxide laser. In a series of 18 patients who underwent this computer-interactive procedure, all experienced a cessation or dramatic reduction in frequency of seizure activity.