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At least 739 records · Page 41Linked to original sources
PubMed1997

Computer-assisted endoscopy for neurosurgical procedures: technical note.

OBJECTIVE: As neuroendoscopy technology evolves, the ventriculoscope is playing a greater role in the diagnosis and treatment of disorders affecting the ventricular system. However, even with direct visualization, correctly orienting and safely navigating an endoscope may be difficult with abnormal anatomy, in small ventricles, or when searching for small periventricular lesions identified on neuroimaging studies. The ability to define the location of the endoscope during such procedures enhances its effectiveness and safety. INSTRUMENTATION: We report the successful adaptation of an image-guided stereotactic wand to a rigid neuroendoscope. With computer-assisted neuroendoscopy (CANE), the tip position and orientation of a rigid ventriculoscope were visualized in real-time on neuroimaging studies that were obtained before surgery. Because computer guidance may also be used with the neuroendoscope obturator during ventricular access, uncertainty in accessing small ventricles is minimized. RESULTS: Eleven patients were operated on at The Cleveland Clinic Foundation using the CANE system. All patients except one were improved after surgery. Early experience suggests that CANE is useful for certain endoscopic procedures by aiding in trajectory planning, ventricular navigation, and localizing certain pathological conditions. CONCLUSION: Even with direct visualization, ventriculoscopy in abnormal anatomy may be difficult. Although the CANE system may not always be necessary in neuroendoscopy, correlation of the endoscope tip location, with an intraoperative magnetic resonance image via continuous computer updates, may enhance the safety, as well as the efficiency, of neuroendoscopy in the future.

Adolescent↗
PubMed2004

Thallium SPECT-based stereotactic targeting for brain tumor biopsies. A technical note.

MR or CT images acquired under stereotactic conditions are often used to plan and guide brain tumor biopsies. The objective of this study was to design and test a methodology to increase target selection reliability by acquiring stereotactic 201Tl-SPECT data and by integrating them into the surgical planning. The three-headed Philips gamma camera system (Prism 3000) was adapted to stereotactic acquisitions (patient pallet, headholder). A software was developed for the stereotactic target determination based on SPECT images (pixel with the highest metabolic activity inside the tumor). The whole system accuracy was tested with the Elekta phantom adapted to SPECT imaging. The methodology was applied to one brain tumor biopsy. Comparison of the specific phantom coordinates evaluated in SPECT with the theoretical ones did not reveal any significant difference. In this way, our methodology including our homemade software (identification of the stereotactic frame, determination of the pixel with highest metabolic activity within the tumor in the stereotactic coordinate system) was validated. No significant geometric deformations were detected. Clinical feasibility was confirmed in 1 patient with a brain glioma. This study illustrates the feasibility and the accuracy of SPECT acquisitions with the stereotactic Leksell G-frame. The clinical relevance of this methodology is under evaluation. This definition of the target, based on the point with the highest metabolic activity within the tumor, might lead to improved diagnosis in biopsies and patient management. Furthermore, it might prepare the future for therapy aimed at delivering a therapeutic agent within a tumor.

Biopsy↗
PubMedDate not supplied

Computed tomogram-guided stereotactic brain biopsy in the pediatric patient.

Experience with computed tomogram-guided stereotactic biopsy is described with special reference to technical considerations important to the application of the Brown-Roberts-Wells system in pediatric patients. Eleven procedures were performed in 9 patients aged 9 months to 16 years of age. In all cases, the lesion was either deep seated or related to deficit prone areas making open biopsy hazardous. Since the stereotactic frame may interfere with intubation, it is important to apply it only after the patient has been anesthetized and intubated. In very small children, special attention is required to avoid over tightening of the fastening pins and to avoid excessive pressure when making the calvarial opening. In an effort to reduce the risk of hemorrhage, vasculature at the entry site was visualized and avoided by making a standard burr hole opening. Improved imaging of the vasculature at the deep biopsy site was obtained in most cases by intra-arterial contrast enhancement. No complications of the procedure were encountered and a diagnosis was obtained in all cases, although in 2 cases the procedure was repeated before adequate tissue was obtained. In 3 cases the procedure was therapeutic as well as diagnostic in that a tumor cyst or abscess could be drained.

Adolescent↗
PubMed1998

[Noninvasive head fixation for external irradiation of tumors of the head-neck area].

PURPOSE: To fully utilize the technical capabilities of radiation diagnostics and planning, a precise and reproducible method of head fixation is a prerequisite. METHOD: We have adapted the Vogele-Bale-Hohner (VBH) head holder (Wellhöfer Dosimetrie, Schwarzenbruck, Germany), originally designed for frameless stereotactic operations, to the requirements of external beam radiotherapy. A precise and reproducible head fixation is attained by an individualized vacuum upper-dental cast which is connected over 2 hydraulic arms to an adjustable head- and rigid base-plate. Radiation field and patient alignment lasers are marked on a relocatable clear PVC localization box. RESULTS: The possibility of craniocaudal adjustment of the head plate on the base plate allows the system to adapt to the actual position of the patient on the radiotherapy couch granting tensionless repositioning. The VBH head holder has proven itself to be a precise yet practicable method of head fixation. Duration of mouthpiece production and daily repositioning is comparable to that of the thermoplastic mask. CONCLUSION: The new head holder is in routine use at our hospital and quite suitable for external beam radiation of patients with tumors of the head and neck.

Equipment Design↗
PubMed1995

Enhanced magnetic resonance imaging of the rat brain using a stereotactic device with a small head coil: technical note.

A stereotactic device (SDM) was developed for performing consistent magnetic resonance imaging (MRI) of the rat brain. The SDM was developed by adapting a radiofrequency transmit/receive head coil of 4.4 cm inner diameter (quadrature birdcage head coil), and utilizing partial acrylic construction for the positioning elements. The small head coil provides improved resolution and accuracy of the image, while the stereotactic holder permits repeatable and accurate imaging of identified brain structures. This system provides several advantages over existing experimental MRI devices. The SDM ensures that the head is always placed in the center of the coil in a uniform fashion. Standardized positioning of the skull optimizes image quality and provides a consistent orientation of the brain. In addition, a widely-utilized coordinate system described by Paxinos and Watson can be employed to assist in the identification of structures and to facilitate surgical planning. The SDM is compatible with a recently-developed stereotactic device for radiosurgery with the Gamma Knife, thus permitting the planning and performance of experimental radiosurgery using the same coordinate system. The SDM also provides the ability to perform MRI and radiosurgery at different times, thus avoiding the need for prolonged anesthesia during an experimental study. Finally, the SDM allows repeated MRI of the same, identifiable positions in the brain during longitudinal experimental studies. The utility of this device is demonstrated here by examining the time course of cerebral damage that evolved within a radiosurgical focus after gamma irradiation.

Animals↗
PubMed2000

SonoWand, an ultrasound-based neuronavigation system.

OBJECTIVE: We have integrated a neuronavigation system into an ultrasound scanner and developed a single-rack system that enables the surgeon to perform frameless and armless stereotactic neuronavigation using intraoperative three-dimensional ultrasound data as well as preoperative magnetic resonance or computed tomographic images. The purpose of this article is to describe our two-rack prototype and present the results of our work on image quality enhancement. DESCRIPTION OF INSTRUMENTATION: The system consists of a high-end ultrasound scanner, a modest-cost computer, and an optical positioning/digitizer system. Special technical and clinical efforts have been made to achieve high image quality. A special interface between the ultrasound instrument and the navigation computer ensures rapid transfer of digital three-dimensional data with no loss of image quality. OPERATIVE TECHNIQUE: The positioning system tracks the position and orientation of the patient, the ultrasound probe, the pointer, and various surgical instruments. This makes it possible to update the three-dimensional map during surgery and navigate by ultrasound data in a similar manner as with magnetic resonance data. METHODS: The two-rack prototype has been used for clinical testing since November 1997 at the University Hospital in Trondheim. EXPERIENCE AND RESULTS: The image quality improvements have enabled us, in most cases, to extract information from ultrasound with clinical value similar to that of preoperative magnetic resonance imaging. The overall clinical accuracy of the ultrasound-based navigation system is expected to be comparable to or better than that of a magnetic resonance imaging-based system. CONCLUSION: The SonoWand system enables neuronavigation through direct use of intraoperative three-dimensional ultrasound. Further research will be necessary to explore the potential clinical value and the limitations of this technology.

Equipment Design↗
PubMed2001

Gamma probe guided biopsy of the sentinel node in malignant melanoma: a multicentre study.

Sentinel lymph node biopsy was attempted in 336 patients with clinically node-negative cutaneous melanoma. All patients were injected with technetium-99m labelled radiocolloid, with 108 patients simultaneously receiving vital blue dye for sentinel node identification. Sentinel lymph nodes were identified in 329 patients, giving a technical success rate of 97.9%. Metastatic disease was identified in 39 (11.9%) of the patients in whom sentinel nodes were found. Patients with negative sentinel nodes were observed and patients with positive sentinel nodes underwent comprehensive lymph node dissection. The presence of metastatic disease in the sentinel nodes and primary tumour depth by Breslow or Clark levels were joint predictors of survival based on Cox proportional hazards modelling. Disease recurrences occurred in 26 (8.8%) patients with negative sentinel lymph nodes, with isolated regional recurrences as the first site in 10 (3.4%). No patients with Clark level II primary tumours were found to have positive sentinel nodes or disease recurrences. One patient with a thin (<0.75 mm) Clark level III primary had metastatic disease in a sentinel node. Patients with metastases confined to the sentinel nodes had similar survival rates regardless of the number of nodes involved.

Adolescent↗
PubMed2000

Comparative examination of the accuracy of a mechanical and an optical system in CT and MRT based instrument navigation.

The aim of an intraoperative instrument navigation system is to support the surgeon in the localization of anatomical regions and to guide the use of surgical instruments. An overview of technical principles and literature reports on various navigation systems is provided here. The navigation accuracy (tested on a plastic phantom under simulated operating room conditions) of the mechanical Viewing Wand system and the optical SPOCS system amounts to 1 to 3 mm for computerized tomography (CT) data, with a significant inverse dependence on the layer thickness. The values for magnetic resonance tomography (MRT) data are significantly higher. In regard to the choice of registration points, a statistically inverse dependence exists between the number of points and the distance between the points. During the time period between autumn 1993 and mid-1999, more than 120 clinical applications were performed. The intraoperative accuracy was in the range of < or = 3 mm. Registering the patient position with preoperatively inserted screw markers achieved accuracy values of < or = 2 mm. The instrument navigation technique has proved to be very advantageous for the spatial orientation of the surgeons. The possibility of checking resection borders has opened up new perspectives in tumor surgery. A quality improvement and a reduction of the operational risks as well as a considerable decline in the stress placed on the patient can be expected in the near future due the techniques of computer-assisted surgery.

Humans↗
PubMed2005

The Stealth Station Image Guidance System may interfere with pulse oximetry.

PURPOSE: Interference on pulse oximetry can come from many sources. We found an additional source of interference from the Stealth Station. This article gives an overview of sources of pulse oximeter interference so that clinicians can better prevent them. Technical features: This article discusses the infrared disturbances caused by the Stealth Station. The Stealth Station is a frameless stereotactic positioning system that utilizes a three dimensional location system to measure the position of the patient and the surgical tools, and to relate those positions to previously recorded imaging. To understand the disturbance caused by the Stealth Station, we discuss its operation and that of pulse oximeter monitors. Pulse oximeter interference can come from volume artifacts, electrical and light noise, and can be caused by issues related to the patient. Because the passive Stealth Station contains a strong infrared light source, interference caused by light is a likely reason for the interference we noted. Pulse oximeters rely on the time-variant light signal modulated by arterial volume variations in the finger. Although relatively immune to static light sources, pulse oximeters are extremely sensitive to time-varying light sources. The light emitted by the passive Stealth Station is time-varying at 4 Hz and this is causing the pulse oximeter to provide invalid results. Shielding can generally be used to stop the light from the Stealth Station from being picked up by the pulse oximeter sensor. CONCLUSION: Infrared light interference can be very common, but is easily dealt with if one is aware of it.

Humans↗
PubMed2001

Revision of deep brain stimulator for tremor. Technical note.

The treatment of essential tremor with thalamic deep brain stimulation (DBS) is considered to be more effective and to cause less morbidity than treatment with thalamotomy. Nonetheless, implantation of an indwelling electrode, connectors, and a generator is associated with specific types of morbidity. The authors describe three patients who required revision of their DBS systems due to lead breakage. The connector between the DBS electrode and the extension wire, which connects to the subclavicular pulse generator, was originally placed subcutaneously in the cervical region to decrease the risk of erosion through the scalp and to improve cosmesis. Three patients presented with fractured DBS electrodes that were located in the cervical region near the connector, necessitating reoperation with stereotactic retargeting and placement of a new intracranial electrode. At reoperation, the connectors were placed subgaleally over the parietal region. Management of these cases has led to modifications in the operative procedure designed to improve the durability of DBS systems. The authors recommend that surgeons avoid placing the connection between the DBS electrode and the extension wire in the cervical region because patient movement can cause microfractures in the electrode. Such microfractures require intracranial revision, which may be associated with a higher risk of morbidity than the initial operation. The authors also recommend considering prophylactic relocation of the connectors from the cervical area to the subgaleal parietal region to decrease the risk of future DBS electrode fracture, which would necessitate a more lengthy procedure to revise the intracranial electrode.

Aged↗
PubMed1994

Accurate placement of coronal ventricular catheter using stereotactic coordinate-guided free-hand passage. Technical note.

Long-term patency of the ventricular catheter of a cerebrospinal fluid shunt depends on the positioning of the hole-bearing segment of the catheter. Placement of this segment near the choroid plexus or injured ependyma increases the probability of obstruction. Proper positioning for a coronal shunt in turn depends on the ventricular catheter length and target coordinates. The authors describe a method of calculating the catheter length based on bone landmarks on skull radiographs, and a technique for accurate ventricular catheter placement using free-hand passage guided by simple stereotactic coordinates based on visible and palpable surface anatomy. The insertion trajectory is aligned with the coronal obliquity of the lateral ventricle so that, even with slit ventricles, the entire hole-bearing segment of the catheter can be reliably situated within the anterior horn. The predetermined catheter length also fixes the tip at the foramen of Monro, away from the choroid plexus and injured ependyma. Of 160 children undergoing ventriculoperitoneal shunt insertion using this technique, only three required catheter revision during a mean follow-up period of 39 months. Radiographic grading of the ventricular catheter position in 112 children showed a satisfactory placement rate of 93.2%; all three children with occlusion showed poor catheter positioning. Thus, this method results in accurate ventricular catheter placement with a 1.9% obstruction rate, which compares favorably to the 16% to 18% incidence of proximal obstruction reported in the literature. This technique is applicable to patients of all ages but is particularly suitable for children because of the greater variability in head size.

Adolescent↗
PubMed2004

SEEG-guided RF thermocoagulation of epileptic foci: feasibility, safety, and preliminary results.

PURPOSE: Depth electrodes recordings may be required in some cases of epilepsy surgery to delineate the best region for cortical resection. We usually implant depth electrodes according to Talairach's stereoelectroencephalography (SEEG) method. By using these permanently implanted depth electrodes, we are able to perform radiofrequency (RF)-thermolesions of the epileptic foci. We report the technical data required to perform such multiple cortical thermolesions, as well as preliminary results in terms of seizure outcome in a group of 20 patients. METHODS: Lesions were performed by using 100- to 110-mA bipolar current (50 V), applied for 10 to 50 s. Each thermocoagulation produced a 5- to 7-mm diameter cortical lesion. In total, two to 16 lesions were performed in each of the 20 patients. Lesions were placed without anesthesia. No general or neurologic complication occurred during the procedures. Two transient postprocedure side effects, consisting of paresthetic sensations in the mouth and mild apraxia of the hand, were observed. RESULTS: At a follow-up time of 8 to 31 months (mean, 19 months), 15% of the patients became seizure free, 40% experienced a > or =80% reduction of their seizure frequency, and 45% were not significantly improved. CONCLUSIONS: SEEG-guided RF thermolesions is a safe technique. Our preliminary results indicate that such lesions can lead to a significant reduction of seizure frequency and could be proposed as a palliative procedure if no resective surgery is possible. A randomized controlled trial is needed to determine which patients are likely to respond to SEEG-guided RF thermolesions.

Adult↗
PubMed2001

Three-dimensional visualization of the pyramidal tract in a neuronavigation system during brain tumor surgery: first experiences and technical note.

OBJECTIVE: To integrate spatial three-dimensional information concerning the pyramidal tracts into a customized system for frameless neuronavigation during brain tumor surgery. METHODS: Four consecutive patients with intracranial tumors in eloquent areas underwent diffusion-weighted and anatomic magnetic resonance imaging studies within 48 hours before surgery. Diffusion-weighted datasets were merged with anatomic data for navigation purposes. The pyramidal tracts were segmented and reconstructed for three-dimensional visualization. The reconstruction results, together with the fused-image dataset, were available during surgery in the environment of a customized neuronavigation system. RESULTS: In all four patients, the combination of reconstructed data and fused images was a helpful additional source of information concerning the tumor seat and topographical interaction with the pyramidal tract. In two patients, intraoperative motor cortex stimulation verified the tumor seat with regard to the precentral gyrus. CONCLUSION: Diffusion-weighted magnetic resonance imaging allows individual estimation of large fiber tracts applicable as important information in intraoperative neuronavigation and in planning brain tumor resection. A three-dimensional representation of fibers associated with the pyramidal tract during brain tumor surgery is feasible with the presented technique and is a helpful adjunct for the neurosurgeon. The main drawbacks include the length of time required for the segmentation procedure, the lack of direct intraoperative control of the pyramidal tract position, and brain shift. However, mapping of large fiber tracts and its intraoperative use for neuronavigation have the potential to increase the safety of neurosurgical procedures and to reduce surgical morbidity.

Aged↗
PubMed2000

Precise cannulation of the foramen ovale in trigeminal neuralgia complicating osteogenesis imperfecta with basilar invagination: technical case report.

OBJECTIVE AND IMPORTANCE: Trigeminal neuralgia is a rare feature of basilar invagination, which is itself a complication of osteochondrodysplastic disorders. Microvascular decompression is an unattractive option in medically refractory cases. The conventional percutaneous approach to the trigeminal ganglion is anatomically impossible because the foramen ovale points inferiorly and posteromedially. We report a new technique for image-guided trigeminal injection in a patient with basilar invagination complicating osteogenesis imperfecta. CLINICAL PRESENTATION: A 26-year-old woman with osteogenesis imperfecta presented with a 3-year history of typical left maxillary division trigeminal neuralgia, which was poorly controlled by carbamazepine at the maximum tolerated dose. She had obvious cranial deformities, left optic atrophy, delayed left eye closure, tongue atrophy, but normal facial sensation and corneal reflexes. A computed tomographic scan and magnetic resonance imaging confirmed severe basilar invagination. TECHNIQUE: Frameless stereotactic glycerol injection of the left trigeminal ganglion was performed under general anesthesia using the infrared-based EasyGuide Neuro system (Philips Medical Systems, Best, The Netherlands) with magnetic resonance imaging and computed tomographic registration. The displaced and distorted left foramen ovale was cannulated via a true frameless stereotactic method with the trajectory determined by virtual pointer elongation. The needle placement was confirmed with injection of contrast medium into the trigeminal cistern. The path needed to enter the foramen traversed the right cheek, soft palate, and left tonsil. The patient went home pain-free with a preserved corneal reflex and no complications. CONCLUSION: Frameless stereotaxy allows customization to individual patient anatomy and may be adapted to a variety of percutaneous procedures used in areas where the anatomy is complex.

Adult↗
PubMed2001

Image-guided, frameless stereotactic sectioning of the corpus callosum in children with intractable epilepsy.

Corpus callosotomy is an effective neurosurgical procedure for children with intractable atonic or drop attack seizures. While this procedure has not changed significantly over the past three decades, some technical issues remain to be resolved. These include the intraoperative determination of the extent of the callosotomy, the need to stage the procedure, as well as side of approach of craniotomy. We report our 8-year experience with corpus callosotomy using a frameless stereotactic image-guided system (ISG Viewing Wand). Seventeen children with atonic seizures underwent sectioning of the corpus callosum. The mean patient age was 10.5 years. Six children underwent complete callosotomy while 11 underwent resection of the anterior two-thirds. MRI 3D reconstruction of the sagittal sinus and draining cerebral veins was undertaken in all cases. The side of the craniotomy was determined on the basis of favorability of the draining veins with respect to the extent of the callosotomy. The extent of the callosotomy was determined by intraoperative feedback using the ISG Viewing Wand((R)). Nine of 11 patients in the partial callosotomy group and 4 of 6 patients in the complete callosotomy group showed significant improvement in atonic seizures. We conclude that the use of frameless stereotaxy can function as an important adjunct in the planning and conduction of successful sectioning of the corpus callosum in children with intractable seizures.

Adolescent↗
PubMed1992

Physics for radiosurgery with linear accelerators.

Radiosurgery had a long development period and, for more than three decades, was used only in a few specialized centers around the world. The development of LINAC-based radiosurgical techniques combined with the concurrent advances in imaging modalities during the 1980s, however, caused so much interest in this treatment modality that most major radiotherapy centers now offer this service or at least plan to offer it in the near future. When considering a LINAC for radiosurgical use, one should remember that technical and clinical requirements for accurate radiosurgery are far more stringent than those applied to standard radiotherapy. This is because in radiosurgery, the targeted volumes are much smaller and the dose is usually delivered in a single irradiation session, whereas in radiotherapy, the dose is delivered to a relatively large target volume on a fractionated basis. Linear accelerator-based radiosurgery broadens the scope of radiotherapy departments. The impetus to introduce this service at a medical center usually comes from neurosurgeons, however. Even after the service becomes routine at an institution, it is the neurosurgeon who refers the patient and who plays the most important role in determining the target volume and its location within the brain. The decision on the choice of isodose surface and the prescribed dose, however, belongs to the radiotherapist. It is becoming clear that radiosurgery is a complex treatment modality for which a successful outcome requires a collaborative team effort by several hospital-based professionals, including neurosurgeons, radiation oncologists, neuroradiologists, and medical physicists. As in standard radiotherapy, physics plays an important role in radiosurgery, not only in the development of target localization, treatment-planning, and dose delivery techniques, but also in the actual patient contact, from the diagnostic target localization procedures, through treatment planning, to patient preparation on the device and dose delivery.

Brain Neoplasms↗
PubMed1997

[Stereotactic brachytherapy for clival chordoma].

There has recently been interest in the use of high-dose radiation with methods such as radiosurgery and brachytherapy for skull base tumors. Brachytherapy is believed to be effective for clival chordomas, but technical difficulties exist in stereotactic insertion of catheters into the clivus. We assessed the usefulness following improvement of implantation techniques in three patients with clival chordomas. All tumors were larger than 50 mm in diameter. Removable iridium-192 sources were held in catheters which were implanted through a transnasal approach under general anesthesia using a CT-guided stereotactic system in one patient and a CRW stereotactic system adapted to a magnetic resonance imaging (MRI) scanner in 2 patients. The implantation array was designed based on results of stereotactic 3-D MRI scanning, and coordinates were calculated for stereotactic implantation through twist drill holes. These catheters were introduced through the nares and directed into the clival chordoma under endoscopic visualization and X-ray fluoroscopy. No complications such as CSF liquorrhea, hemorrhage or infection were observed. Brachytherapy with a total dose of 43.2-58.0 Gy at the tumor periphery was administered for 7 to 10 days, and serial follow-up imaging studies demonstrated reduction in tumor size in two patients and no tumor growth in the other. Our results suggested that stereotactic brachytherapy is potentially useful for the control of clival chordomas and that computer-guided transnasal stereotactic insertion enables implantation of catheters less invasively and more accurately than does X-ray fluoroscopic guidance alone.

Adolescent↗
PubMed1999

Variability in lesion location after microelectrode-guided pallidotomy for Parkinson's disease: anatomical, physiological, and technical factors that determine lesion distribution.

OBJECT: To understand the factors that determine the distribution of lesions after microelectrode-guided pallidotomy for Parkinson's disease, the authors quantitatively characterized lesion location in a cohort of patients who were prospectively followed to determine the effects of pallidotomy on clinical outcome. METHODS: Thirty-three patients underwent volumetric magnetic resonance (MR) imaging after surgery to allow quantitative lesion localization in relation to conventional intraventricular landmarks and, alternatively, more anatomically relevant landmarks. The validity of the method was verified in a cohort of postpallidotomy patients who underwent concurrent volumetric and stereotactic MR imaging in an external head frame. Lesions were distributed over a considerable distance in the anteroposterior (8.8 mm) and mediolateral (8.7 mm) dimensions in relation to the anterior commissure and wall of the third ventricle, respectively. Less variation was seen in lesion location in the dorsoventral dimension (4.8 mm) in relation to the intercommissural plane. CONCLUSIONS: Lesion distribution was not random: lesion locations in the anteroposterior and mediolateral dimensions were highly correlated, such that lesions were distributed from anteromedial to posterolateral, parallel to the border of the globus pallidus internus with the obliquely oriented internal capsule. The factors that led to variability in lesion location were variation in third ventricle width and the oblique anteromedial-to-posterolateral course of the internal capsule. This demonstration of variability of lesion location in a cohort of patients who experienced excellent clinical benefits and minimal postoperative complications emphasizes the importance of anatomical variations in determining lesion position and the need for physiological corroboration for correct lesion placement.

Adult↗