Magnetoencephalography-guided surgery in frontal lobe epilepsy using neuronavigation and intraoperative MR imaging.

PubMed

Sommer, Björn; Roessler, Karl; Rampp, Stefan; Hamer, Hajo M; Blumcke, Ingmar; Stefan, Hermann; Buchfelder, Michael

2016-10-01

Especially in hidden lesions causing drug-resistant frontal lobe epilepsy (FLE), the localization of the epileptic zone EZ can be a challenge. Magnetoencephalography (MEG) can raise the chances for localization of the (EZ) in combination with electroencephalography (EEG). We investigated the impact of MEG-guided epilepsy surgery with the aid of neuronavigation and intraoperative MR imaging (iopMRI) on seizure outcome of FLE patients. Twenty-eight patients (15 females, 13 males; mean age 31.0±11.1 years) underwent surgery in our department. All patients underwent presurgical MEG monitoring (two-sensor Magnes II or whole head WH3600 MEG system; 4-D Neuroimaging, San Diego, CA, USA). Of those, six patients (group 1) with MRI-negative FLE were operated on before 2002 with intraoperative electrocorticography (ECoG) and invasive EEG mapping only. Eleven patients with MRI-negative FLE (group 2) and eleven with lesional FLE (group 3) underwent surgery using 1.5T-iopMRI and neuronavigation, including intraoperative visualization of the MEG localizations in 22 and functional MR imaging (for motor and speech areas) as well as DTI fiber tracking (for language and pyramidal tracts) in 13 patients. In the first group, complete resection of the defined EZ including the MEG localization according to the latest postoperative MRI was achieved in four out of six patients. Groups two and three had complete removal of the MEG localizations in 20/22 (91%, 10 of 11 each). Intraoperative MRI revealed incomplete resection of the MEG localizations of four patients (12%; two in both groups), leading to successful re-resection. Transient and permanent neurological deficits alike occurred in 7.1%, surgery-associated complications in 11% of all patients. In the first group, excellent seizure outcome (Engel Class IA) was achieved in three (50%), in the second in 7 patients (61%) and third group in 8 patients (64%, two iopMRI-based re-resections). Mean follow-up was 70.3 months (from 12 to 284

Integration of 3D intraoperative ultrasound for enhanced neuronavigation

NASA Astrophysics Data System (ADS)

Paulsen, Keith D.; Ji, Songbai; Hartov, Alex; Fan, Xiaoyao; Roberts, David W.

2012-03-01

True three-dimensional (3D) volumetric ultrasound (US) acquisitions stand to benefit intraoperative neuronavigation on multiple fronts. While traditional two-dimensional (2D) US and its tracked, hand-swept version have been recognized for many years to advantage significantly image-guided neurosurgery, especially when coregistered with preoperative MR scans, its unregulated and incomplete sampling of the surgical volume of interest have limited certain intraoperative uses of the information that are overcome through direct volume acquisition (i.e., through 2D scan-head transducer arrays). In this paper, we illustrate several of these advantages, including image-based intraoperative registration (and reregistration) and automated, volumetric displacement mapping for intraoperative image updating. These applications of 3D US are enabled by algorithmic advances in US image calibration, and volume rasterization and interpolation for multi-acquisition synthesis that will also be highlighted. We expect to demonstrate that coregistered 3D US is well worth incorporating into the standard neurosurgical navigational environment relative to traditional tracked, hand-swept 2D US.

Clinical indications for high-field 1.5 T intraoperative magnetic resonance imaging and neuro-navigation for neurosurgical procedures. Review of initial 100 cases.

PubMed

Maesawa, Satoshi; Fujii, Masazumi; Nakahara, Norimoto; Watanabe, Tadashi; Saito, Kiyoshi; Kajita, Yasukazu; Nagatani, Tetsuya; Wakabayashi, Toshihiko; Yoshida, Jun

2009-08-01

Initial experiences are reviewed in an integrated operation theater equipped with an intraoperative high-field (1.5 T) magnetic resonance (MR) imager and neuro-navigation (BrainSUITE), to evaluate the indications and limitations. One hundred consecutive cases were treated, consisting of 38 gliomas, 49 other tumors, 11 cerebrovascular diseases, and 2 functional diseases. The feasibility and usefulness of the integrated theater were evaluated for individual diseases, focusing on whether intraoperative images (including diffusion tensor imaging) affected the surgical strategy. The extent of resection and outcomes in each histological category of brain tumors were examined. Intraoperative high-field MR imaging frequently affected or modified the surgical strategy in the glioma group (27/38 cases, 71.1%), but less in the other tumor group (13/49 cases, 26.5%). The surgical strategy was not modified in cerebrovascular or functional diseases, but the success of procedures and the absence of complications could be confirmed. In glioma surgery, subtotal or greater resection was achieved in 22 of the 31 patients (71%) excluding biopsies, and intraoperative images revealed tumor remnants resulting in the extension of resection in 21 of the 22 patients (95.4%), the highest rate of extension among all types of pathologies. The integrated neuro-navigation improved workflow. The best indication for intraoperative high-field MR imaging and integrated neuro-navigation is brain tumors, especially gliomas, and is supplementary in assuring quality in surgery for cerebrovascular or functional diseases. Immediate quality assurance is provided in several types of neurosurgical procedures.

Accuracy and Precision of a Veterinary Neuronavigation System for Radiation Oncology Positioning

PubMed Central

Ballegeer, Elizabeth A.; Frey, Stephen; Sieffert, Rob

2018-01-01

Conformal radiation treatment plans such as IMRT and other radiosurgery techniques require very precise patient positioning, typically within a millimeter of error for best results. CT cone beam, real-time navigation, and infrared position sensors are potential options for success but rarely present in veterinary radiation centers. A neuronavigation system (Brainsight Vet, Rogue Research) was tested 22 times on a skull for positioning accuracy and precision analysis. The first 6 manipulations allowed the authors to become familiar with the system but were still included in the analyses. Overall, the targeting mean error in 3D was 1.437 mm with SD 1.242 mm. This system could be used for positioning for radiation therapy or radiosurgery. PMID:29666822

Integrating magnetic resonance imaging postprocessing results into neuronavigation for electrode implantation and resection of subtle focal cortical dysplasia in previously cryptogenic epilepsy.

PubMed

Wellmer, Jörg; Parpaley, Yaroslav; von Lehe, Marec; Huppertz, Hans-Jürgen

2010-01-01

Focal cortical dysplasias (FCDs) are highly epileptogenic lesions. Surgical removal is frequently the best treatment option for pharmacoresistant epilepsy. However, subtle FCDs may remain undetected even after high-resolution magnetic resonance imaging (MRI). Morphometric MRI analysis, which compares the individual brain with a normal database, can facilitate the detection of FCDs. We describe how the results of normal database-based MRI postprocessing can be used to guide stereotactic electrode implantation and subsequent resection of lesions that are suspected to be FCDs. A presurgical evaluation was conducted on a 19-year-old woman with pharmacoresistant hypermotor seizures. Conventional high-resolution MRI was classified as negative for epileptogenic lesions. However, morphometric analysis of the spatially normalized MRI revealed abnormal gyration and blurring of the gray-white matter junction, which was suggestive of a small and deeply seated FCD in the left frontal lobe. The brain region highlighted by morphometric analysis was marked as a region of interest, transferred back to the original dimension of the individual MRI, and imported into a neuronavigation system. This allowed the region of interest-targeted stereotactic implantation of 2 depth electrodes, by which seizure onset was confirmed in the lesion. The electrodes also guided the final resection, which rendered the patient seizure-free. The lesion was histologically classified as FCD Palmini and Lüders IIB. Transferring normal database-based MRI postprocessing results into a neuronavigation system is a new and worthwhile extension of multimodal neuronavigation. The combination of resulting regions of interest with functional and anatomic data may facilitate planning of electrode implantation for invasive electroencephalographic recordings and the final resection of small or deeply seated FCDs.

Minimally invasive neurosurgery within a 0.5 tesla intraoperative magnetic resonance scanner using an off-line neuro-navigation system.

PubMed

Mursch, K; Gotthardt, T; Kröger, R; Bublat, M; Behnke-Mursch, J

2005-08-01

We evaluated an advanced concept for patient-based navigation during minimally invasive neurosurgical procedures. An infrared-based, off-line neuro-navigation system (LOCALITE, Bonn, Germany) was applied during operations within a 0.5 T intraoperative MRI scanner (iMRI) (Signa SF, GE Medical Systems, Milwaukee, WI, USA) in addition to the conventional real-time system. The three-dimensional (3D) data set was acquired intraoperatively and up-dated when brain-shift was suspected. Twenty-three patients with subcortical lesions were operated upon with the aim to minimise the operative trauma. Small craniotomies (median diameter 30 mm, mean diameter 27 mm) could be placed exactly. In all cases, the primary goal of the operation (total resection or biopsy) was achieved in a straightforward procedure without permanent morbidity. The navigation system could be easily used without technical problems. In contrast to the real-time navigation mode of the MR system, the higher quality as well as the real-time display of the MR images reconstructed from the 3D reference data provided sufficient visual-manual coordination. The system combines the advantages of conventional neuro-navigation with the ability to adapt intraoperatively to the continuously changing anatomy. Thus, small and/or deep lesions can be operated upon in straightforward minimally invasive operations.

Improvements in symptoms following neuronavigated repetitive transcranial magnetic stimulation (rTMS) in severe and enduring anorexia nervosa: findings from two case studies.

PubMed

McClelland, Jessica; Bozhilova, Natali; Nestler, Steffen; Campbell, Iain C; Jacob, Shirabdi; Johnson-Sabine, Eric; Schmidt, Ulrike

2013-11-01

Advances in the treatment of anorexia nervosa (AN) are most likely to arise from targeted, brain-directed treatments, such as repetitive transcranial magnetic stimulation (rTMS). We describe findings from two individuals with treatment-resistant AN who received 19-20 sessions of neuronavigated, high frequency rTMS, applied to the left dorsolateral prefrontal cortex. Within-session measures assessed changes pre-rTMS, post-rTMS in subjective eating disorder (ED) experiences. Weight, ED symptoms and mood were assessed pre-treatment, post-treatment and at 1 month follow-up. In both cases, there was improvement in ED symptomatology and mood after 19-20 sessions of neuronavigated rTMS, and these changes persisted or continued to improve at follow-up. Within sessions, Patient A demonstrated a consistent reduction in subjective ED experiences, and Patient B a reduction in some ED related experiences. These findings suggest that rTMS has potential as an adjunct to the treatment of AN and deserves further study. Copyright © 2013 John Wiley & Sons, Ltd and Eating Disorders Association.

[High-Definition Exoscope System for Microneurosurgery:Use of an Exoscope in Combination with Tubular Retraction and Frameless Neuronavigation for Microsurgical Resection of Deep Brain Lesions].

PubMed

Nagatani, Kimihiro; Takeuchi, Satoru; Feng, Dongxia; Mori, Kentaro; Day, J Diaz

2015-07-01

The high-definition exoscope (VITOM®, Karl Storz GmbH & Co., Tuttlingen, Germany) is a new equipment that can be used as an alternative to the operating microscope in neurosurgery. Several neurosurgeons have recently reported that the exoscope allows for long working distances and great depth of field. Herein, we review reported cases of exoscope use in neurosurgery. We also describe the advantages of the exoscope compared to the operating microscope and endoscope. Furthermore, we introduce a novel technique for microsurgical resection of deep brain lesions, in which the exoscope is used along with tubular retraction and frameless neuronavigation. Before the operation, neuronavigation is registered and the surgical trajectory is planned to avoid damaging the functional cortex and eloquent white matter tracts. By using intraoperative neuronavigation, the tubular retractor (NICO BrainPath®, NICO Corporation, Indianapolis, US), which is designed to split the white matter when gently inserted, is inserted transcortically into the brain to reach the lesion, along the preplanned trajectory. After insertion, the tubular retractor is fixed in place using a self-retaining arm. This creates a narrow corridor that enables the use of the exoscope (for optimum visualization), bimanual dissection technique, and long bayoneted surgical instruments. The large focal distance of the exoscope allows it to be placed sufficiently further away from the surgical site, permitting the passage of long surgical instruments under the scope. Although obtaining surgical access to deep-seated brain lesions is challenging, we consider that this technique facilitates a safe surgical approach for lesions in deep locations.

Short term outcomes following surgery in brain tumours sans neuronavigation.

PubMed

Rashid, Mamoon Ur; Junaid, Muhammad; Bukhari, Syed Sarmad; Afsheen, Afeera

2018-02-01

To determine the presentation and frequency of various intracranial neoplasms and assess outcomes for patients who underwent surgery without neuronavigation. This retrospective study was conducted at Combined Military Hospital, Peshawar, Pakistan, and comprised medical records related to the period from August 2011 to July 2014. Patient histories, examination reports and preoperative and post-operative radiological scans were reviewed and extent of excision was determined based on these coupled with recurrence rates. Intraoperatively, tumour excision was determined largely by the experience of the surgeon and preoperative planning using bony landmarks and radiological scans as an objective guide to resection. SPSS 21 was used for data analysis. Of the 143 patients, 83(57.9%) were males and 60(42.1%)were females. Gliomas were the most common tumours, occurring in 20(33.3%) females and 35(42.2%) males. One-year survival rate for grade 4 astrocytomas was poor (39.4%) and was excellent for meningiomas (100%) and pituitary tumours (100%). Time-tested methods of careful neurological examination and knowledge of neuroanatomy can allow a surgeon with limited resources to plan and accommodate for accurate tumour resection with adequate margins.

3D printing and intraoperative neuronavigation tailoring for skull base reconstruction after extended endoscopic endonasal surgery: proof of concept.

PubMed

Essayed, Walid I; Unadkat, Prashin; Hosny, Ahmed; Frisken, Sarah; Rassi, Marcio S; Mukundan, Srinivasan; Weaver, James C; Al-Mefty, Ossama; Golby, Alexandra J; Dunn, Ian F

2018-03-02

OBJECTIVE Endoscopic endonasal approaches are increasingly performed for the surgical treatment of multiple skull base pathologies. Preventing postoperative CSF leaks remains a major challenge, particularly in extended approaches. In this study, the authors assessed the potential use of modern multimaterial 3D printing and neuronavigation to help model these extended defects and develop specifically tailored prostheses for reconstructive purposes. METHODS Extended endoscopic endonasal skull base approaches were performed on 3 human cadaveric heads. Preprocedure and intraprocedure CT scans were completed and were used to segment and design extended and tailored skull base models. Multimaterial models with different core/edge interfaces were 3D printed for implantation trials. A novel application of the intraoperative landmark acquisition method was used to transfer the navigation, helping to tailor the extended models. RESULTS Prostheses were created based on preoperative and intraoperative CT scans. The navigation transfer offered sufficiently accurate data to tailor the preprinted extended skull base defect prostheses. Successful implantation of the skull base prostheses was achieved in all specimens. The progressive flexibility gradient of the models' edges offered the best compromise for easy intranasal maneuverability, anchoring, and structural stability. Prostheses printed based on intraprocedure CT scans were accurate in shape but slightly undersized. CONCLUSIONS Preoperative 3D printing of patient-specific skull base models is achievable for extended endoscopic endonasal surgery. The careful spatial modeling and the use of a flexibility gradient in the design helped achieve the most stable reconstruction. Neuronavigation can help tailor preprinted prostheses.

Intraoperative Magnetic-Resonance Tomography and Neuronavigation During Resection of Focal Cortical Dysplasia Type II in Adult Epilepsy Surgery Offers Better Seizure Outcomes.

PubMed

Roessler, Karl; Kasper, Burkhard S; Heynold, Elisabeth; Coras, Roland; Sommer, Björn; Rampp, Stefan; Hamer, Hajo M; Blümcke, Ingmar; Buchfelder, Michael

2018-01-01

Focal cortical dysplasia (FCD) is one important cause of drug-resistant epilepsy potentially curable by epilepsy surgery. We investigated the options of using neuronavigation and intraoperative magnetic-resonance tomographical imaging (MRI) to avoid residual epileptogenic tissue during resection of patients with FCD II to improve seizure outcome. Altogether, 24 patients with FCD II diagnosed by MRI (16 female, 8 male; mean age 34 ± 10 years) suffered from drug-resistant electroclinical and focal epilepsy for a mean of 20.7 ± 5 years. Surgery was performed with preoperative stereoelectroencephalography (in 15 patients), neuronavigation, and intraoperative 1.5T-iopMRI in all 24 investigated patients. In 75% of patients (18/24), a complete resection was performed. In 89% (16/18) of completely resected patients, we documented an Engel I seizure outcome after a mean follow-up of 42 months. All incompletely resected patients had a worse outcome (Engel II-III, P < 0.0002). Patients with FCD IIB had also significant better seizure outcome compared with patients diagnosed as having FCD IIA (82% vs. 28%, P < 0.02). In 46% (11/24) of patients, intraoperative second-look surgeries due to residual lesions detected during the intraoperative MRI were performed. In these 11 patients, there were significant more completely seizure free patients (73% vs. 38% Engel IA), compared with 13 patients who finished surgery after the first intraoperative MRI (P < 0.05). Excellent seizure outcome after surgery of patients with FCD II positively correlated with the amount of resection, histologic subtype, and the use of intraoperative MRI, especially when intraoperative second-look surgeries were performed. Copyright © 2017 Elsevier Inc. All rights reserved.

Endoscopic Endonasal Transclival Approach to the Ventral Brainstem: Anatomic Study of the Safe Entry Zones Combining Fiber Dissection Technique with 7 Tesla Magnetic Resonance Guided Neuronavigation.

PubMed

Weiss, Alessandro; Perrini, Paolo; De Notaris, Matteo; Soria, Guadalupe; Carlos, Alarcon; Castagna, Maura; Lutzemberger, Lodovico; Santonocito, Orazio Santo; Catapano, Giuseppe; Kassam, Amin; Galino, Alberto Prats

2018-05-10

Treatment of intrinsic lesions of the ventral brainstem is a surgical challenge that requires complex skull base antero- and posterolateral approaches. More recently, endoscopic endonasal transclival approach (EETA) has been reported in the treatment of selected ventral brainstem lesions. In this study we explored the endoscopic ventral brainstem anatomy with the aim to describe the degree of exposure of the ventral safe entry zones. In addition, we used a newly developed method combining traditional white matter dissection with high-resolution 7T magnetic resonance imaging (MRI) of the same specimen coregistered using a neuronavigation system. Eight fresh-frozen latex-injected cadaver heads underwent EETA. Additional 8 formalin-fixed brainstems were dissected using Klingler technique guided by ultra-high resolution MRI. The EETA allows a wide exposure of different safe entry zones located on the ventral brainstem: the exposure of perioculomotor zone requires pituitary transposition and can be hindered by superior cerebellar artery. The peritrigeminal zone was barely visible and its exposure required an extradural anterior petrosectomy. The anterolateral sulcus of the medulla was visible in most of specimens, although its close relationship with the corticospinal tract makes it suboptimal as an entry point for intrinsic lesions. In all cases, the use of 7T-MRI allowed the identification of tiny fiber bundles, improving the quality of the dissection. Exposure of the ventral brainstem with EETA requires mastering surgical maneuvers, including pituitary transposition and extradural petrosectomy. The correlation of fiber dissection with 7T-MRI neuronavigation significantly improves the understanding of the brainstem anatomy.

Neuronavigation Based on Track Density Image Extracted from Deterministic High-Definition Fiber Tractography.

PubMed

Wei, Peng-Hu; Cong, Fei; Chen, Ge; Li, Ming-Chu; Yu, Xin-Guang; Bao, Yu-Hai

2017-02-01

Diffusion tensor imaging-based navigation is unable to resolve crossing fibers or to determine with accuracy the fanning, origin, and termination of fibers. It is important to improve the accuracy of localizing white matter fibers for improved surgical approaches. We propose a solution to this problem using navigation based on track density imaging extracted from high-definition fiber tractography (HDFT). A 28-year-old asymptomatic female patient with a left-lateral ventricle meningioma was enrolled in the present study. Language and visual tests, magnetic resonance imaging findings, both preoperative and postoperative HDFT, and the intraoperative navigation and surgery process are presented. Track density images were extracted from tracts derived using full q-space (514 directions) diffusion spectrum imaging (DSI) and integrated into a neuronavigation system. Navigation accuracy was verified via intraoperative records and postoperative DSI tractography, as well as a functional examination. DSI successfully represented the shape and range of the Meyer loop and arcuate fasciculus. Extracted track density images from the DSI were successfully integrated into the navigation system. The relationship between the operation channel and surrounding tracts was consistent with the postoperative findings, and the patient was functionally intact after the surgery. DSI-based TDI navigation allows for the visualization of anatomic features such as fanning and angling and helps to identify the range of a given tract. Moreover, our results show that our HDFT navigation method is a promising technique that preserves neural function. Copyright © 2016 Elsevier Inc. All rights reserved.

The Trans-Visible Navigator: A See-Through Neuronavigation System Using Augmented Reality.

PubMed

Watanabe, Eiju; Satoh, Makoto; Konno, Takehiko; Hirai, Masahiro; Yamaguchi, Takashi

2016-03-01

The neuronavigator has become indispensable for brain surgery and works in the manner of point-to-point navigation. Because the positional information is indicated on a personal computer (PC) monitor, surgeons are required to rotate the dimension of the magnetic resonance imaging/computed tomography scans to match the surgical field. In addition, they must frequently alternate their gaze between the surgical field and the PC monitor. To overcome these difficulties, we developed an augmented reality-based navigation system with whole-operation-room tracking. A tablet PC is used for visualization. The patient's head is captured by the back-face camera of the tablet. Three-dimensional images of intracranial structures are extracted from magnetic resonance imaging/computed tomography and are superimposed on the video image of the head. When viewed from various directions around the head, intracranial structures are displayed with corresponding angles as viewed from the camera direction, thus giving the surgeon the sensation of seeing through the head. Whole-operation-room tracking is realized using a VICON tracking system with 6 cameras. A phantom study showed a spatial resolution of about 1 mm. The present system was evaluated in 6 patients who underwent tumor resection surgery, and we showed that the system is useful for planning skin incisions as well as craniotomy and the localization of superficial tumors. The main advantage of the present system is that it achieves volumetric navigation in contrast to conventional point-to-point navigation. It extends augmented reality images directly onto real surgical images, thus helping the surgeon to integrate these 2 dimensions intuitively. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Endoscopic intracranial surgery enhanced by electromagnetic-guided neuronavigation in children.

PubMed

Hermann, Elvis J; Esmaeilzadeh, Majid; Ertl, Philipp; Polemikos, Manolis; Raab, Peter; Krauss, Joachim K

2015-08-01

Navigated intracranial endoscopy with conventional technique usually requires sharp head fixation. In children, especially in those younger than 1 year of age and in older children with thin skulls due to chronic hydrocephalus, sharp head fixation is not possible. Here, we studied the feasibility, safety, and accuracy of electromagnetic (EM)-navigated endoscopy in a series of children, obviating the need of sharp head fixation. Seventeen children (ten boys, seven girls) between 12 days and 16.8 years (mean age 4.3 years; median 14 months) underwent EM-navigated intracranial endoscopic surgery based on 3D MR imaging of the head. Inclusion criteria for the study were intraventricular cysts, arachnoid cysts, aqueduct stenosis for endoscopic third ventriculostomy (ETV) with distorted ventricular anatomy, the need of biopsy in intraventricular tumors, and multiloculated hydrocephalus. A total of 22 endoscopic procedures were performed. Patients were registered for navigation by surface rendering in the supine position. After confirming accuracy, they were repositioned for endoscopic surgery with the head fixed slightly on a horseshoe headholder. EM navigation was performed using a flexible stylet introduced into the working channel of a rigid endoscope. Neuronavigation accuracy was checked for deviations measured in millimeters on screenshots after the referencing procedure and during surgery in the coronal (z = vertical), axial (x = mediolateral), and sagittal (y = anteroposterior) planes. EM-navigated endoscopy was feasible and safe. In all 17 patients, the aim of endoscopic surgery was achieved, except in one case in which a hemorrhage occurred, blurring visibility, and we proceeded with open surgery without complications for the patient. Navigation accuracy for extracranial markers such as the tragus, bregma, and nasion ranged between 1 and 2.5 mm. Accuracy for fixed anatomical structures like the optic nerve or the carotid artery varied between 2 and 4

Image-guided removal of supratentorial cavernomas in critical brain areas: application of neuronavigation and intraoperative magnetic resonance imaging.

PubMed

Gralla, J; Ganslandt, O; Kober, H; Buchfelder, M; Fahlbusch, R; Nimsky, C

2003-04-01

In a retrospective study the postoperative results of 26 patients operated on for supratentorial cavernous hemangiomas either deep-seated or near eloquent brain areas are summarized. An exact surgical approach to these lesions is essential to prevent neurological deterioration. Three different navigation systems were used and compared according to their clinical applicability. Complete removal of the lesion was obtained in all patients of this series. In six cases (23 %) functional data from magnetoencephalography or functional magnetic resonance imaging were integrated into the navigational setup. In 14 cases (54 %) intraoperative magnetic resonance imaging was performed. The follow-up time was 3 - 26 months (mean: 10 months). In the postoperative course one patient (3.8 %) developed a hemiparesis, another one developed quadrantopia. Nineteen patients presented with preoperative seizure history, 16 of these (84 %) had no further or rare seizures after surgery. The better results in seizure control were achieved in those patients with shorter duration of seizure history before surgery. The study indicates that the application of neuronavigation allows surgery on supratentorial cavernous hemangiomas in critical brain areas with low morbidity. The intraoperative visualization of eloquent cortex areas by integration of functional data allows a fast identification and exemption of eloquent brain areas, preventing neurological deterioration. Furthermore, the intraoperative MR resection control ensures a complete resection and illustrates the minimal invasive approach.

Investigation of subdural electrode displacement in invasive epilepsy surgery workup using neuronavigation and intraoperative MRI.

PubMed

Sommer, Bjoern; Rampp, Stefan; Doerfler, Arnd; Stefan, Hermann; Hamer, Hajo M; Buchfelder, Michael; Roessler, Karl

2018-06-19

One of the main obstacles of electrode implantation in epilepsy surgery is the electrode shift between implantation and the day of explantation. We evaluated this possible electrode displacement using intraoperative MRI (iopMRI) data and CT/MRI reconstruction. Thirteen patients (nine female, four male, median age 26 ± 9.4 years) suffering from drug-resistant epilepsy were examined. After implantation, the position of subdural electrodes was evaluated by 3.0 T-MRI and thin-slice CCT for 3D reconstruction. Localization of electrodes was performed with the volume-rendering technique. Post-implantation and pre-explantation 1.5 T-iopMRI scans were coregistered with the 3D reconstructions to determine the extent of electrode dislocation. Intraoperative MRI at the time of explantation revealed a relevant electrode shift in one patient (8%) of 10 mm. Median electrode displacement was 1.7 ± 2.6 mm with a coregistration error of 1.9 ± 0.7 mm. The median accuracy of the neuronavigation system was 2.2 ± 0.9 mm. Six of twelve patients undergoing resective surgery were seizure free (Engel class 1A, median follow-up 37.5 ± 11.8 months). Comparison of pre-explantation and post-implantation iopMRI scans with CT/MRI data using the volume-rendering technique resulted in an accurate placement of electrodes. In one patient with a considerable electrode dislocation, the surgical approach and extent was changed due to the detected electrode shift. ECoG: electrocorticography; EZ: epileptogenic zone; iEEG: invasive EEG; iopMRI: intraoperative MRI; MEG: magnetoencephalography; PET: positron emission tomography; SPECT: single photon emission computed tomography; 3D: three-dimensional.

Augmented reality-assisted skull base surgery.

PubMed

Cabrilo, I; Sarrafzadeh, A; Bijlenga, P; Landis, B N; Schaller, K

2014-12-01

Neuronavigation is widely considered as a valuable tool during skull base surgery. Advances in neuronavigation technology, with the integration of augmented reality, present advantages over traditional point-based neuronavigation. However, this development has not yet made its way into routine surgical practice, possibly due to a lack of acquaintance with these systems. In this report, we illustrate the usefulness and easy application of augmented reality-based neuronavigation through a case example of a patient with a clivus chordoma. We also demonstrate how augmented reality can help throughout all phases of a skull base procedure, from the verification of neuronavigation accuracy to intraoperative image-guidance. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Effects of inhibitory theta burst TMS to different brain sites involved in visuospatial attention - a combined neuronavigated cTBS and behavioural study.

PubMed

Platz, Thomas; Schüttauf, Johannes; Aschenbach, Julia; Mengdehl, Christine; Lotze, Martin

2016-01-01

The study sought to alter visual spatial attention in young healthy subjects by a neuronavigated inhibitory rTMS protocol (cTBS-600) to right brain areas thought to be involved in visual attentional processes, i.e. the temporoparietal junction (TPJ) and the posterior middle frontal gyrus (pMFG), and to test the reversibility of effects by an additional consecutive cTBS to the homologue left brain cortical areas. Healthy subjects showed a leftward bias of the egocentric perspective for both visual-perceptive and visual-exploratory tasks specifically for items presented in the left hemifield. cTBS to the right TPJ, and less systematically to the right pMFG reduced this bias for visuo-spatial and exploratory visuo-motor behaviour. Further, a consecutive cTBS to the left TPJ changed the bias again towards the left for a visual-perceptive task. The evidence supports the notion of an involvement of the right TPJ (and pMFG) in spatial visual attention. The observations further indicate that inhibitory non-invasive brain stimulation (cTBS) to the left TPJ has a potential for reversing a rightward bias of spatial attention when the right TPJ is dysfunctional. Accordingly, the findings could have implications for therapeutic rTMS development for right brain damaged patients with visual neglect.

Simulated ventriculostomy training with conventional neuronavigational equipment used clinically in the operating room: prospective validation study.

PubMed

Kirkman, Matthew A; Muirhead, William; Sevdalis, Nick; Nandi, Dipankar

2015-01-01

Simulation is gaining increasing interest as a method of delivering high-quality, time-effective, and safe training to neurosurgical residents. However, most current simulators are purpose-built for simulation, being relatively expensive and inaccessible to many residents. The purpose of this study was to provide the first comprehensive validity assessment of ventriculostomy performance metrics from the Medtronic StealthStation S7 Surgical Navigation System, a neuronavigational tool widely used in the clinical setting, as a training tool for simulated ventriculostomy while concomitantly reporting on stress measures. A prospective study where participants performed 6 simulated ventriculostomy attempts on a model head with StealthStation-coregistered imaging. The performance measures included distance of the ventricular catheter tip to the foramen of Monro and presence of the catheter tip in the ventricle. Data on objective and self-reported stress and workload measures were also collected. The operating rooms of the National Hospital for Neurology and Neurosurgery, Queen Square, London. A total of 31 individuals with varying levels of prior ventriculostomy experience, varying in seniority from medical student to senior resident. Performance at simulated ventriculostomy improved significantly over subsequent attempts, irrespective of previous ventriculostomy experience. Performance improved whether or not the StealthStation display monitor was used for real-time visual feedback, but performance was optimal when it was. Further, performance was inversely correlated with both objective and self-reported measures of stress (traditionally referred to as concurrent validity). Stress and workload measures were well-correlated with each other, and they also correlated with technical performance. These initial data support the use of the StealthStation as a training tool for simulated ventriculostomy, providing a safe environment for repeated practice with immediate feedback

A Smartphone App to Assist Scalp Localization of Superficial Supratentorial Lesions--Technical Note.

PubMed

Eftekhar, Behzad

2016-01-01

Neuronavigation is an established technology in neurosurgery. In parts of the world and certain circumstances in which neuronavigation is not easily available or affordable, alternative techniques may be considered. An app to assist scalp localization of superficial supratentorial lesions has been introduced, and its accuracy has been compared with established neuronavigation systems. Sina is a simple smartphone app that overlaps the transparent patients' computed tomography/magnetic resonance images on the background camera. How to use Sina intraoperatively is described. The app was used for scalp localization of the center of the lesions in 11 patients with supratentorial pathologies <3 cm in longest diameter and <2 cm from the cortex. After localization of the lesion using Sina, the center of the lesion was marked on the scalp using standard neuronavigation systems and the deviations were measured. Implementation of Sina for intraoperative scalp localization is simple and practical. The center of the lesions localized by Sina was 10.2 ± 2 mm different from localization done by standard neuronavigation systems. When neuronavigation is not easily available or affordable, Sina can be helpful for scalp localization and preoperative planning of the incision for selected supratentorial pathologies. Copyright © 2016 Elsevier Inc. All rights reserved.

A new head-mounted display-based augmented reality system in neurosurgical oncology: a study on phantom.

PubMed

Cutolo, Fabrizio; Meola, Antonio; Carbone, Marina; Sinceri, Sara; Cagnazzo, Federico; Denaro, Ennio; Esposito, Nicola; Ferrari, Mauro; Ferrari, Vincenzo

2017-12-01

Benefits of minimally invasive neurosurgery mandate the development of ergonomic paradigms for neuronavigation. Augmented Reality (AR) systems can overcome the shortcomings of commercial neuronavigators. The aim of this work is to apply a novel AR system, based on a head-mounted stereoscopic video see-through display, as an aid in complex neurological lesion targeting. Effectiveness was investigated on a newly designed patient-specific head mannequin featuring an anatomically realistic brain phantom with embedded synthetically created tumors and eloquent areas. A two-phase evaluation process was adopted in a simulated small tumor resection adjacent to Broca's area. Phase I involved nine subjects without neurosurgical training in performing spatial judgment tasks. In Phase II, three surgeons were involved in assessing the effectiveness of the AR-neuronavigator in performing brain tumor targeting on a patient-specific head phantom. Phase I revealed the ability of the AR scene to evoke depth perception under different visualization modalities. Phase II confirmed the potentialities of the AR-neuronavigator in aiding the determination of the optimal surgical access to the surgical target. The AR-neuronavigator is intuitive, easy-to-use, and provides three-dimensional augmented information in a perceptually-correct way. The system proved to be effective in guiding skin incision, craniotomy, and lesion targeting. The preliminary results encourage a structured study to prove clinical effectiveness. Moreover, our testing platform might be used to facilitate training in brain tumour resection procedures.

[Application of diffusion tensor imaging fractography in minimally invasive surgery of brain tumors].

PubMed

Yang, Lei; Zhang, Mao-zhi; Zhang, Wei; Zhao, Yuan-li; Zhao, Ji-zong

2006-05-23

To investigate the effects and prospect of application of diffusion tensor imaging (DTI) fractography in minimally invasive surgery of brain tumors. DTI fractography was performed in 52 patients with malignant brain tumors. Based on the DTI fractography results, 34 of the 52 patients underwent operation under neuro-navigation, and 18 of the 52 patients underwent operation routine minimally invasive craniotomy and tumor resection without neuro-navigation. The rate of total tumor resection was 86.5% (45/52). The mortality was 1.9% (1/52). The disability rate was 11.5% (6/52). No case needed the second operation. DTI fractography has raised the minimally invasive neurosurgery to the level of protecting the nuclei and nerve tracts and guiding intra-operative management of infiltration of deep-seated tumors, especially when combined with neuro-navigation and interventional MRI.

Functional Magnetic Resonance Imaging (fMRI), Pre-intraoperative Tractography in Neurosurgery: The Experience of Sant' Andrea Rome University Hospital.

PubMed

D'Andrea, Giancarlo; Trillo', Giuseppe; Picotti, Veronica; Raco, Antonino

2017-01-01

The goal of neurosurgery for cerebral intraparenchymal neoplasms of the eloquent areas is maximal resection with the preservation of normal functions, and minimizing operative risk and postoperative morbidity. Currently, modern technological advances in neuroradiological tools, neuronavigation, and intraoperative magnetic resonance imaging (MRI) have produced great improvements in postoperative morbidity after the surgery of cerebral eloquent areas. The integration of preoperative functional MRI (fMRI), intraoperative MRI (volumetric and diffusion tensor imaging [DTI]), and neuronavigation, defined as "functional neuronavigation" has improved the intraoperative detection of the eloquent areas. We reviewed 142 patients operated between 2004 and 2010 for intraparenchymal neoplasms involving or close to one or more major white matter tracts (corticospinal tract [CST], arcuate fasciculus [AF], optic radiation). All the patients underwent neurosurgery in a BrainSUITE equipped with a 1.5 T MR scanner and were preoperatively studied with fMRI and DTI for tractography for surgical planning. The patients underwent MRI and DTI during surgery after dural opening, after the gross total resection close to the white matter tracts, and at the end of the procedure. We evaluated the impact of fMRI on surgical planning and on the selection of the entry point on the cortical surface. We also evaluated the impact of preoperative and intraoperative DTI, in order to modify the surgical approach, to define the borders of resection, and to correlate this modality with subcortical neurophysiological monitoring. We evaluated the impact of the preoperative fMRI by intraoperative neurophysiological monitoring, performing "neuronavigational" brain mapping, following its data to localize the previously elicited areas after brain shift correction by intraoperative MRI. The mean age of the 142 patients (89 M/53 F) was 59.1 years and the lesion involved the CST in 66 patients (57 %), the language

Transcranial and Epidural Approach for Spontaneous Cerebrospinal Fluid Leakage Due to Meningoencephalocele of the Lateral Sphenoid Sinus.

PubMed

Shintoku, Ryosuke; Tosaka, Masahiko; Shimizu, Tatsuya; Yoshimoto, Yuhei

2018-01-01

We experienced a case of sphenoid sinus type meningoencephalocele manifesting as severe cerebrospinal fluid (CSF) rhinorrhea. A 35-year-old man became aware of serous nasal discharge 1 year previously, which had gradually worsened. The nasal discharge was diagnosed as CSF rhinorrhea. Head computed tomography (CT) showed several small depressions in the bone of the left middle cranial fossa, and the largest depression extended through the bone to the lateral sphenoid sinus. Head magnetic resonance imaging revealed that the meningoencephalocele projected to the lateral sphenoid sinus, through this small bone defect of the middle cranial fossa. We performed a combined craniotomy and epidural approach without intradural procedures using neuronavigation. Multiple meningoencephaloceles protruded into small depressions in the middle skull base. The small protrusions not passing through the sphenoid sinus were coagulated. The largest protrusion causing the CSF leakage was identified by neuronavigation. This meningoencephalocele was cut. Both the dural and bone sides were closed with double layers to prevent CSF leakage. The CSF rhinorrhea completely stopped after the surgery. In our case, identification of the leak site was easy with neuronavigation based on bone window CT. The epidural approach also has significant advantages with double layer closure, including both the dural and bone sides. If the site of CSF leakage is outside the foramen rotundum (as with the most common type of lateral sphenoid sinus meningoencephalocele), we recommend the epidural approach using neuronavigation for surgical treatment.

Presurgical Planning for Supratentorial Lesions with Free Slicer Software and Sina App.

PubMed

Chen, Ji-Gang; Han, Kai-Wei; Zhang, Dan-Feng; Li, Zhen-Xing; Li, Yi-Ming; Hou, Li-Jun

2017-10-01

Neuronavigation systems are used widely in the localization of intracranial lesions with satisfactory accuracy. However, they are expensive and difficult to learn. Therefore, a simple and practical augmented reality (AR) system using mobile devices might be an alternative technique. We introduce a mobile AR system for the localization of supratentorial lesions. Its practicability and accuracy were examined by clinical application in patients and comparison with a standard neuronavigation system. A 3-dimensional (3D) model including lesions was created with 3D Slicer. A 2-dimensional image of this 3D model was obtained and overlapped on the patient's head with the Sina app. Registration was conducted with the assistance of anatomical landmarks and fiducial markers. The center of lesion projected on scalp was identified with our mobile AR system and standard neuronavigation system, respectively. The difference in distance between the centers identified by these 2 systems was measured. Our mobile AR system was simple and accurate in the localization of supratentorial lesions with a mean distance difference of 4.4 ± 1.1 mm. Registration added on an average of 141.7 ± 39 seconds to operation time. There was no statistically significant difference for the required time among 3 registrations (P = 0.646). The mobile AR system presents an alternative technology for image-guided neurosurgery and proves to be practical and reliable. The technique contributes to optimal presurgical planning for supratentorial lesions, especially in the absence of a neuronavigation system. Copyright © 2017 Elsevier Inc. All rights reserved.

Focal brainstem gliomas

PubMed Central

Sabbagh, Abdulrahman J.; Alaqeel, Ahmed M.

2015-01-01

Improved neuronavigation guidance as well as intraoperative imaging and neurophysiologic monitoring technologies have enhanced the ability of neurosurgeons to resect focal brainstem gliomas. In contrast, diffuse brainstem gliomas are considered to be inoperable lesions. This article is a continuation of an article that discussed brainstem glioma diagnostics, imaging, and classification. Here, we address open surgical treatment of and approaches to focal, dorsally exophytic, and cervicomedullary brainstem gliomas. Intraoperative neuronavigation, intraoperative neurophysiologic monitoring, as well as intraoperative imaging are discussed as adjunctive measures to help render these procedures safer, more acute, and closer to achieving surgical goals. PMID:25864061

Image guided neuroendoscopy for third ventriculostomy.

PubMed

Broggi, G; Dones, I; Ferroli, P; Franzini, A; Servello, D; Duca, S

2000-01-01

Third ventriculostomy has become an increasing popular procedure for the treatment of hydrocephalus of different aetiologies. Between october 1997 and october 1998, 17 patients (12 females, 5 males; 12-82 year-old; mean age 43) underwent image-assisted endoscopic third ventriculostomy for hydrocephalus at the Istituto Nazionale Neurologico "C.Besta" of Milano. There was no mortality and no long term morbidity. Neuronavigation has been found useful in selecting the safest trajectory to the target avoiding any traction on the foramen of Monro related structures and allowing the necessary mobility for fine adjustments under visual and "tactile" control when choosing the safest point to perform the stoma. According to our experience neuro-endoscopy and neuronavigation seems to be complementary in reaching easy, safe and successful results in the treatment of hydrocephalus of different origins.

MRI-Guided Regional Personalized Electrical Stimulation in Multisession and Home Treatments

PubMed Central

Cancelli, Andrea; Cottone, Carlo; Giordani, Alessandro; Asta, Giampiero; Lupoi, Domenico; Pizzella, Vittorio; Tecchio, Franca

2018-01-01

The shape and position of the electrodes is a key factor for the efficacy of transcranial electrical stimulations (tES). We have recently introduced the Regional Personalized Electrode (RePE), a tES electrode fitting the personal cortical folding, that has been able to differentiate the stimulation of close by regions, in particular the primary sensory (S1) and motor (M1) cortices, and to personalize tES onto such an extended cortical district. However, neuronavigation on individual brain was compulsory for the correct montage. Here, we aimed at developing and testing a neuronavigation-free procedure for easy and quick positioning RePE, enabling multisession RePE-tES at home. We used off-line individual MRI to shape RePE via an ad-hoc computerized procedure, while an ad-hoc developed Adjustable Helmet Frame (AHF) was used to properly position it in multisession treatments, even at home. We used neuronavigation to test the RePE shape and position obtained by the new computerized procedure and the re-positioning obtained via the AHF. Using Finite Element Method (FEM) model, we also estimated the intra-cerebral current distribution induced by transcranial direct current stimulation (tDCS) comparing RePE vs. non-RePE with fixed reference. Additionally, we tested, using FEM, various shapes, and positions of the reference electrode taking into account possible small displacements of RePE, to test feasibility of RePE-tES sessions at home. The new RePE neuronavigation-free positioning relies on brain MRI space distances, and produced a mean displacement of 3.5 ± 0.8 mm, and the re-positioning of 4.8 ± 1.1 mm. Higher electric field in S1 than in M1 was best obtained with the occipital reference electrode, a montage that proved to feature low sensitivity to typical RePE millimetric displacements. Additionally, a new tES accessory was developed to enable repositioning the electrodes over the scalp also at home, with a precision which is acceptable according to the modeling

The Assessment of Distortion in Neurosurgical Image Overlay Projection.

PubMed

Vakharia, Nilesh N; Paraskevopoulos, Dimitris; Lang, Jozsef; Vakharia, Vejay N

2016-02-01

Numerous studies have demonstrated the superiority of neuronavigation during neurosurgical procedures compared to non-neuronavigation-based procedures. Limitations to neuronavigation systems include the need for the surgeons to avert their gaze from the surgical field and the cost of the systems, especially for hospitals in developing countries. Overlay projection of imaging directly onto the patient allows localization of intracranial structures. A previous study using overlay projection demonstrated the accuracy of image coregistration for a lesion in the temporal region but did not assess image distortion when projecting onto other anatomical locations. Our aim is to quantify this distortion and establish which regions of the skull would be most suitable for overlay projection. Using the difference in size of a square grid when projected onto an anatomically accurate model skull and a flat surface, from the same distance, we were able to calculate the degree of image distortion when projecting onto the skull from the anterior, posterior, superior, and lateral aspects. Measuring the size of a square when projected onto a flat surface from different distances allowed us to model change in lesion size when projecting a deep structure onto the skull surface. Using 2 mm as the upper limit for distortion, our results show that images can be accurately projected onto the majority (81.4%) of the surface of the skull. Our results support the use of image overlay projection in regions with ≤2 mm distortion to assist with localization of intracranial lesions at a fraction of the cost of existing methods. © The Author(s) 2015.

Image-guided neurosurgery for secondary operative removal of projectiles after missile injury of the brain.

PubMed

Schulz, Chris; Woerner, Ulrich; Luelsdorf, Peter

2008-04-01

The primary treatment of penetrating missile injuries of the brain includes debridement of the scalp, fractured skull, and necrotic brain parenchyma. It is acceptable to remove all bony and metallic fragments that are accessible without additional trauma to nondamaged brain regions. Therefore, bone chips and bullets are often initially retained in the brain and are supposedly responsible for delayed cerebral infections and posttraumatic seizures. We successfully operated on 3 patients electively to remove bony and metallic fragments secondarily after penetrating brain trauma. We used an electromagnetic neuronavigation system for preoperative planning and chose a less invasive approach for the exact intraoperative localization of the fragments. All fragments were extracted without any problems. No patients had any additional neurologic deficits, and no signs of cerebral infections or seizures occurred between 4 and 8 weeks after the operative revision. We recommend the implementation of neuronavigation techniques into the surgical strategy for secondary removal of retained missile fragments.

StimTrack: An open-source software for manual transcranial magnetic stimulation coil positioning.

PubMed

Ambrosini, Emilia; Ferrante, Simona; van de Ruit, Mark; Biguzzi, Stefano; Colombo, Vera; Monticone, Marco; Ferriero, Giorgio; Pedrocchi, Alessandra; Ferrigno, Giancarlo; Grey, Michael J

2018-01-01

During Transcranial Magnetic Stimulation (TMS) experiments researchers often use a neuronavigation system to precisely and accurately maintain coil position and orientation. This study aimed to develop and validate an open-source software for TMS coil navigation. StimTrack uses an optical tracker and an intuitive user interface to facilitate the maintenance of position and orientation of any type of coil within and between sessions. Additionally, online access to navigation data is provided, hereby adding e.g. the ability to start or stop the magnetic stimulator depending on the distance to target or the variation of the orientation angles. StimTrack allows repeatable repositioning of the coil within 0.7mm for translation and <1° for rotation. Stimulus-response (SR) curves obtained from 19 healthy volunteers were used to demonstrate that StimTrack can be effectively used in a typical experiment. An excellent intra and inter-session reliability (ICC >0.9) was obtained on all parameters computed on SR curves acquired using StimTrack. StimTrack showed a target accuracy similar to that of a commercial neuronavigation system (BrainSight, Rogue Research Inc.). Indeed, small differences both in position (∼0.2mm) and orientation (<1°) were found between the systems. These differences are negligible given the human error involved in landmarks registration. StimTrack, available as supplementary material, is found to be a good alternative for commercial neuronavigation systems facilitating assessment changes in corticospinal excitability using TMS. StimTrack allows researchers to tailor its functionality to their specific needs, providing added value that benefits experimental procedures and improves data quality. Copyright © 2017 Elsevier B.V. All rights reserved.

[Role of the intraoperative electrical brain stimulation in conserving the speech and language function in neurosurgical procedures on conscious patients].

PubMed

Eross, Loránd; Fekete, Gábor; Entz, László; Fabó, Dániel; Borbély, Csaba; Kozák, Lajos Rudolf; Andrejkovics, Mónika; Czirják, Sándor; Fedorcsák, Imre; Novák, László; Bognár, László

2012-09-30

To summarize the results gained with awake craniotomies, which were performed in either low grade glioma patients or epilepsy surgical patients whose tumor or epileptogenic zone, was in the vicinity of eloquent, mostly language, cortices. PATIENT SELECTION AND METHODS: In our retrospective study we selected 16 patients who were operated awake between 1999-2011 at the Neurosurgical Department of MAV Kórház Budapest, or at the National Institute of Neurosciences in Budapest, or at the Neurosurgical Department of the University of Debrecen in Debrecen. In the presurgical evaluation if it was possible we performed functional magnetic resonance imaging, tractography and detailed neuropsychological testing. At the National Institute of Neurosciences all patients were operated with the aid of MR guided neuronavigation. Anesthesia was carried out without complications in all of the 16 cases. Monitoring of sleep deepness has significantly contributed to the safety of anesthesia during the superficial anesthezied states of the operation. The intraoperative neuropsychological tasks used for testing language were sensitive enough to judge the little disturbances in speech during stimulation. Stimulation evoked seizures could be adequately managed during surgery and did not influence the outcome of the procedures. The use of neuronavigation helped significantly by planning the optimal place for the craniotomy and by intraoperative orientation. Awake craniotomies require well practiced surgical teams, which requires the cooperation of neuro-anesthesiologits, neurosurgeons, neuropsychologist and electrophysiologists. It has two goals, first to reduce the time of surgery to minimize surgical complications, secondly the detailed intraoperative mapping of cognitive and motor functions to avoid any neurological deficit. The intraoperative anatomical data provided by the neuronavigation and the functional data provided by awake intraoperative stimulation of the patient together

The benefit of image guidance for the contralateral interhemispheric approach to the lateral ventricle.

PubMed

Fronda, Chiara; Miller, Dorothea; Kappus, Christoph; Bertalanffy, Helmut; Sure, Ulrich

2008-06-01

Recently, neurosurgeons have increasingly faced small intracerebral lesions in asymptomatic or minimally symptomatic patients. Here, we evaluated a series of four patients with nearly asymptomatic intraventricular tumors close to the corpus callosum that had been treated with the aid of an image-guided transcallosal approach. Four consecutive patients suffering from left intra- and paraventricular tumors were operated on via a contralateral interhemispheric transcallosal approach with the aid of neuronavigation. Our image-guided system directed: (1) the skin incision, (2) the interhemispheric dissection, and (3) the incision of the corpus callosum. Using the image-guided contralateral interhemispheric transcallosal approach to the left ventricle all lesions have been completely resected without the risk of damage to the dominant hemisphere. The callosal incision was kept as limited as possible (1.2-2.1cm) depending on the size of the tumor. No postoperative neurological or neuropsychological deficit was observed in our series. Neuronavigation facilitates a safe and targeted contralateral interhemispheric transcallosal approach to the dominant hemisphere's lateral ventricle. Our technique minimizes the risk of damage to the dominant hemisphere and requires only a limited opening of the corpus callosum, which might decrease the risk of neuropsychological morbidity.

Augmented reality in neurovascular surgery: feasibility and first uses in the operating room.

PubMed

Kersten-Oertel, Marta; Gerard, Ian; Drouin, Simon; Mok, Kelvin; Sirhan, Denis; Sinclair, David S; Collins, D Louis

2015-11-01

The aim of this report is to present a prototype augmented reality (AR) intra-operative brain imaging system. We present our experience of using this new neuronavigation system in neurovascular surgery and discuss the feasibility of this technology for aneurysms, arteriovenous malformations (AVMs), and arteriovenous fistulae (AVFs). We developed an augmented reality system that uses an external camera to capture the live view of the patient on the operating room table and to merge this view with pre-operative volume-rendered vessels. We have extensively tested the system in the laboratory and have used the system in four surgical cases: one aneurysm, two AVMs and one AVF case. The developed AR neuronavigation system allows for precise patient-to-image registration and calibration of the camera, resulting in a well-aligned augmented reality view. Initial results suggest that augmented reality is useful for tailoring craniotomies, localizing vessels of interest, and planning resection corridors. Augmented reality is a promising technology for neurovascular surgery. However, for more complex anomalies such as AVMs and AVFs, better visualization techniques that allow one to distinguish between arteries and veins and determine the absolute depth of a vessel of interest are needed.

Intraoperative visualisation of functional structures facilitates safe frameless stereotactic biopsy in the motor eloquent regions of the brain.

PubMed

Zhang, Jia-Shu; Qu, Ling; Wang, Qun; Jin, Wei; Hou, Yuan-Zheng; Sun, Guo-Chen; Li, Fang-Ye; Yu, Xin-Guang; Xu, Ban-Nan; Chen, Xiao-Lei

2017-12-20

For stereotactic brain biopsy involving motor eloquent regions, the surgical objective is to enhance diagnostic yield and preserve neurological function. To achieve this aim, we implemented functional neuro-navigation and intraoperative magnetic resonance imaging (iMRI) into the biopsy procedure. The impact of this integrated technique on the surgical outcome and postoperative neurological function was investigated and evaluated. Thirty nine patients with lesions involving motor eloquent structures underwent frameless stereotactic biopsy assisted by functional neuro-navigation and iMRI. Intraoperative visualisation was realised by integrating anatomical and functional information into a navigation framework to improve biopsy trajectories and preserve eloquent structures. iMRI was conducted to guarantee the biopsy accuracy and detect intraoperative complications. The perioperative change of motor function and biopsy error before and after iMRI were recorded, and the role of functional information in trajectory selection and the relationship between the distance from sampling site to nearby eloquent structures and the neurological deterioration were further analyzed. Functional neuro-navigation helped modify the original trajectories and sampling sites in 35.90% (16/39) of cases to avoid the damage of eloquent structures. Even though all the lesions were high-risk of causing neurological deficits, no significant difference was found between preoperative and postoperative muscle strength. After data analysis, 3mm was supposed to be the safe distance for avoiding transient neurological deterioration. During surgery, the use of iMRI significantly reduced the biopsy errors (p = 0.042) and potentially increased the diagnostic yield from 84.62% (33/39) to 94.87% (37/39). Moreover, iMRI detected intraoperative haemorrhage in 5.13% (2/39) of patients, all of them benefited from the intraoperative strategies based on iMRI findings. Intraoperative visualisation of

Use of the Brainlab Disposable Stylet for endoscope and peel-away navigation.

PubMed

Halliday, Jane; Kamaly, Ian

2016-12-01

Neuronavigation, the ability to perform real-time intra-operative guidance during cranial and/or spinal surgery, has increased both accuracy and safety in neurosurgery [2]. Cranial navigation of existing surgical instruments using Brainlab requires the use of an instrument adapter and clamp, which in our experience renders an endoscope 'top-heavy', difficult to manipulate, and the process of registration of the adapter quite time-consuming. A Brainlab Disposable Stylet was used to navigate fenestration of an entrapped temporal horn in a pediatric case. Accuracy was determined by target visualization relative to neuronavigation targeting. Accuracy was also calculated using basic trigonometry to establish the maximum tool tip inaccuracy for the disposible stylet inserted into a peel-away (Codman) and endoscope. The Brainlab Disposable Stylet was easier to use, more versatile, and as accurate as use of an instrument adapter and clamp. The maximum tool-tip inaccuracy for the endoscope was 0.967 mm, and the Codman peel-away 0.489 mm. A literature review did not reveal any reports of use of the Brainlab Disposable Stylet in this way, and we are unaware of this being used in common neurosurgical practice. We would recommend this technique in endoscopic cases that require use of Brainlab navigation.

BRAIN initiative: fast and parallel solver for real-time monitoring of the eddy current in the brain for TMS applications.

PubMed

Sabouni, Abas; Pouliot, Philippe; Shmuel, Amir; Lesage, Frederic

2014-01-01

This paper introduce a fast and efficient solver for simulating the induced (eddy) current distribution in the brain during transcranial magnetic stimulation procedure. This solver has been integrated with MRI and neuronavigation software to accurately model the electromagnetic field and show eddy current in the head almost in real-time. To examine the performance of the proposed technique, we used a 3D anatomically accurate MRI model of the 25 year old female subject.

Quantifying surgical access in eyebrow craniotomy with and without orbital bar removal: cadaver and surgical phantom studies.

PubMed

Zador, Zsolt; Coope, David J; Gnanalingham, Kanna; Lawton, Michael T

2014-04-01

Eyebrow craniotomy is a recently described minimally invasive approach for tackling primarily pathology of the anterior skull base. The removal of the orbital bar may further expand the surgical corridor of this exposure, but the extent of benefit is poorly quantified. We assessed the effect of orbital bar removal with regards to surgical access in the eyebrow craniotomy using classic morphometric measurements in cadaver heads. Using surgical phantoms and neuronavigation, we also measured the 'working volume', a new parameter for characterising the volume of surgical access in these approaches. Silicon injected cadaver heads (n = 5) were used for morphometric analysis of the eyebrow craniotomy with and without orbital bar removal. Working depths and 'working areas' of surgical access were measured as defined by key anatomical landmarks. The eyebrow craniotomy with or without orbital bar removal was also simulated using surgical phantoms (n = 3, 90-120 points per trial), calibrated against a frameless neuronavigation system. Working volume was derived from reference coordinates recorded along the anatomical borders of the eyebrow craniotomy using the "α-shape algorithm" in R statistics. In cadaver heads, eyebrow craniotomy with removal of the orbital bar reduced the working depth to the ipsilateral anterior clinoid process (42 ± 2 versus 33 ± 3 mm; p < 0.05), but the working areas as defined by deep neurovascular and bony landmarks was statistically unchanged (total working areas of 418 ± 80 cm(2) versus 334 ± 48 cm(2); p = 0.4). In surgical phantom studies, however, working-volume for the simulated eyebrow craniotomies was increased with orbital bar removal (16 ± 1 cm(3) versus 21 ± 1 cm(3); p < 0.01). In laboratory studies, orbital bar removal in eyebrow craniotomy provides a modest reduction in working depth and increase in the working volume. But this must be weighed up against the added morbidity of the

Long-term effects of repetitive transcranial magnetic stimulation (rTMS) in patients with chronic tinnitus.

PubMed

Kleinjung, Tobias; Eichhammer, Peter; Langguth, Berthold; Jacob, Peter; Marienhagen, Joerg; Hajak, Goeran; Wolf, Stephan R; Strutz, Juergen

2005-04-01

The pathophysiologic mechanisms of idiopathic tinnitus remain unclear. Recent studies demonstrated focal brain activation in the auditory cortex of patients with chronic tinnitus. Low-frequency repetitive transcranial magnetic stimulation (rTMS) is able to reduce cortical hyperexcitability. Fusing of the individual PET-scan with the structural MRI-scan (T1, MPRAGE) allowed us to identify exactly the area of increased metabolic activity in the auditory cortex of patients with chronic tinnitus. With the use of a neuronavigational system, this target area was exactly stimulated by the figure 8-shaped magnetic coil. In a prospective study, rTMS (110% motor threshold; 1 Hz; 2000 stimuli/day over 5 days) was performed using a placebo controlled cross-over design. Patients were blinded regarding the stimulus condition. For the sham stimulation a specific sham-coil system was used. Fourteen patients were followed for 6 months. Treatment outcome was assessed with a specific tinnitus questionnaire (Goebel and Hiller). Tertiary referral medical center. Increased metabolic activation in the auditory cortex was verified in all patients. After 5 days of verum rTMS, a highly significant improvement of the tinnitus score was found whereas the sham treatment did not show any significant changes. The treatment outcome after 6 months still demonstrated significant reduction of tinnitus score. These preliminary results demonstrate that neuronavigated rTMS offers new possibilities in the understanding and treatment of chronic tinnitus.

Transcranial magnetic stimulation assisted by neuronavigation of magnetic resonance images

NASA Astrophysics Data System (ADS)

Viesca, N. Angeline; Alcauter, S. Sarael; Barrios, A. Fernando; González, O. Jorge J.; Márquez, F. Jorge A.

2012-10-01

Technological advance has improved the way scientists and doctors can learn about the brain and treat different disorders. A non-invasive method used for this is Transcranial Magnetic Stimulation (TMS) based on neuron excitation by electromagnetic induction. Combining this method with functional Magnetic Resonance Images (fMRI), it is intended to improve the localization technique of cortical brain structures by designing an extracranial localization system, based on Alcauter et al. work.

Thoracic, Lumbar, and Sacral Pedicle Screw Placement Using Stryker-Ziehm Virtual Screw Technology and Navigated Stryker Cordless Driver 3: Technical Note.

PubMed

Satarasinghe, Praveen; Hamilton, Kojo D; Tarver, Michael J; Buchanan, Robert J; Koltz, Michael T

2018-04-17

Utilization of pedicle screws (PS) for spine stabilization is common in spinal surgery. With reliance on visual inspection of anatomical landmarks prior to screw placement, the free-hand technique requires a high level of surgeon skill and precision. Three-dimensional (3D), computer-assisted virtual neuronavigation improves the precision of PS placement and minimization steps. Twenty-three patients with degenerative, traumatic, or neoplastic pathologies received treatment via a novel three-step PS technique that utilizes a navigated power driver in combination with virtual screw technology. (1) Following visualization of neuroanatomy using intraoperative CT, a navigated 3-mm match stick drill bit was inserted at an anatomical entry point with a screen projection showing a virtual screw. (2) A Navigated Stryker Cordless Driver with an appropriate tap was used to access the vertebral body through a pedicle with a screen projection again showing a virtual screw. (3) A Navigated Stryker Cordless Driver with an actual screw was used with a screen projection showing the same virtual screw. One hundred and forty-four consecutive screws were inserted using this three-step, navigated driver, virtual screw technique. Only 1 screw needed intraoperative revision after insertion using the three-step, navigated driver, virtual PS technique. This amounts to a 0.69% revision rate. One hundred percent of patients had intraoperative CT reconstructed images taken to confirm hardware placement. Pedicle screw placement utilizing the Stryker-Ziehm neuronavigation virtual screw technology with a three step, navigated power drill technique is safe and effective.

Sodium Fluorescein-Guided Resection under the YELLOW 560 nm Surgical Microscope Filter in Malignant Gliomas: Our First 38 Cases Experience.

PubMed

Zhang, Ningning; Tian, Hailong; Huang, Dezhang; Meng, Xianbing; Guo, Wenqiang; Wang, Chaochao; Yin, Xin; Zhang, Hongying; Jiang, Bin; He, Zheng; Wang, Zhigang

2017-01-01

Sodium fluorescein (FL) had been safely used in fluorescence-guided microsurgery for imaging various brain tumors. Under the YELLOW 560 nm surgical microscope filter, low-dose FL as a fluorescent dye helps in visualization. Our study investigated the safety and efficacy of this innovative technique in malignant glioma (MG) patients. 38 patients suffering from MGs confirmed by pathology underwent FL-guided resection under YELLOW 560 nm surgical microscope filter. We retrospectively analyzed the clinical characters, microsurgery procedure, extent of resection, pathology of MGs, progression-free survival (PFS), and overall survival (OS). Thirty-eight patients had MGs (10 WHO grade III, 28 WHO grade IV). With YELLOW 560 nm surgical microscope filter combined with neuronavigation, sodium fluorescein-guided gross total resection (GTR) was achieved in 35 (92.1%) patients and subtotal resection in 3 (7.69%). The sensitivity and specificity of FL were 94.4% and 88.6% regardless of radiographic localization. Intraoperatively, 10 biopsies (10/28 FL[+]) showed "low" or "high" fluorescence in non-contrast-enhancement region and are also confirmed by pathology. Our data showed 6-month PFS of 92.3% and median survival of 11 months. FL-guided resection of MGs under the YELLOW 560 nm surgical microscope filter combined with neuronavigation was safe and effective, especially in non-contrast-MRI regions. It is feasible for improving the extent of resection in MGs especially during emergency cases.

Pre-operative planning and intra-operative guidance in modern neurosurgery: a review of 300 cases.

PubMed Central

Wadley, J.; Dorward, N.; Kitchen, N.; Thomas, D.

1999-01-01

Operative neurosurgery has recently entered an exciting era of image guided surgery or neuronavigation and application of this novel technology is beginning to have a significant impact in many ways in a variety of intracranial procedures. In order to fully assess the advantages of image guided techniques over conventional planning and surgery in selected cases, detailed prospective evaluation has been carried out during the advanced development of an optically tracked neuronavigation system. Over a 2-year period, 300 operative neurosurgical procedures have been performed with the assistance of interactive image guidance, as well as the development of new software applications and hardware tools. A broad range of intracranial neurosurgical procedures were seen to benefit from image guidance, including 163 craniotomies, 53 interactive stereotactic biopsies, 7 tracked neuroendoscopies and 37 complex skull base procedures. The most common pathological diagnoses were cerebral glioma in 98 cases, meningioma in 64 and metastasis in 23. Detailed analysis of a battery of postoperative questions revealed benefits in operative planning, appreciation of anatomy, lesion location, safety of surgery and greatly enhanced surgical confidence. The authors believe that image guided surgical technology, with new developments such as those described, has a significant role to play in contemporary neurosurgery and its widespread adoption in practice will be realised in the near future. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 PMID:10615186

Sodium Fluorescein-Guided Resection under the YELLOW 560 nm Surgical Microscope Filter in Malignant Gliomas: Our First 38 Cases Experience

PubMed Central

Tian, Hailong; Huang, Dezhang; Meng, Xianbing; Guo, Wenqiang; Wang, Chaochao; Yin, Xin; Zhang, Hongying; Jiang, Bin; He, Zheng

2017-01-01

Objective Sodium fluorescein (FL) had been safely used in fluorescence-guided microsurgery for imaging various brain tumors. Under the YELLOW 560 nm surgical microscope filter, low-dose FL as a fluorescent dye helps in visualization. Our study investigated the safety and efficacy of this innovative technique in malignant glioma (MG) patients. Patients and Method 38 patients suffering from MGs confirmed by pathology underwent FL-guided resection under YELLOW 560 nm surgical microscope filter. We retrospectively analyzed the clinical characters, microsurgery procedure, extent of resection, pathology of MGs, progression-free survival (PFS), and overall survival (OS). Results Thirty-eight patients had MGs (10 WHO grade III, 28 WHO grade IV). With YELLOW 560 nm surgical microscope filter combined with neuronavigation, sodium fluorescein-guided gross total resection (GTR) was achieved in 35 (92.1%) patients and subtotal resection in 3 (7.69%). The sensitivity and specificity of FL were 94.4% and 88.6% regardless of radiographic localization. Intraoperatively, 10 biopsies (10/28 FL[+]) showed “low” or “high” fluorescence in non-contrast-enhancement region and are also confirmed by pathology. Our data showed 6-month PFS of 92.3% and median survival of 11 months. Conclusion FL-guided resection of MGs under the YELLOW 560 nm surgical microscope filter combined with neuronavigation was safe and effective, especially in non-contrast-MRI regions. It is feasible for improving the extent of resection in MGs especially during emergency cases. PMID:29124069

Intra-temporal facial nerve centerline segmentation for navigated temporal bone surgery

NASA Astrophysics Data System (ADS)

Voormolen, Eduard H. J.; van Stralen, Marijn; Woerdeman, Peter A.; Pluim, Josien P. W.; Noordmans, Herke J.; Regli, Luca; Berkelbach van der Sprenkel, Jan W.; Viergever, Max A.

2011-03-01

Approaches through the temporal bone require surgeons to drill away bone to expose a target skull base lesion while evading vital structures contained within it, such as the sigmoid sinus, jugular bulb, and facial nerve. We hypothesize that an augmented neuronavigation system that continuously calculates the distance to these structures and warns if the surgeon drills too close, will aid in making safe surgical approaches. Contemporary image guidance systems are lacking an automated method to segment the inhomogeneous and complexly curved facial nerve. Therefore, we developed a segmentation method to delineate the intra-temporal facial nerve centerline from clinically available temporal bone CT images semi-automatically. Our method requires the user to provide the start- and end-point of the facial nerve in a patient's CT scan, after which it iteratively matches an active appearance model based on the shape and texture of forty facial nerves. Its performance was evaluated on 20 patients by comparison to our gold standard: manually segmented facial nerve centerlines. Our segmentation method delineates facial nerve centerlines with a maximum error along its whole trajectory of 0.40+/-0.20 mm (mean+/-standard deviation). These results demonstrate that our model-based segmentation method can robustly segment facial nerve centerlines. Next, we can investigate whether integration of this automated facial nerve delineation with a distance calculating neuronavigation interface results in a system that can adequately warn surgeons during temporal bone drilling, and effectively diminishes risks of iatrogenic facial nerve palsy.

Applications of Ultrasound in the Resection of Brain Tumors

PubMed Central

Sastry, Rahul; Bi, Wenya Linda; Pieper, Steve; Frisken, Sarah; Kapur, Tina; Wells, William; Golby, Alexandra J.

2016-01-01

Neurosurgery makes use of pre-operative imaging to visualize pathology, inform surgical planning, and evaluate the safety of selected approaches. The utility of pre-operative imaging for neuronavigation, however, is diminished by the well characterized phenomenon of brain shift, in which the brain deforms intraoperatively as a result of craniotomy, swelling, gravity, tumor resection, cerebrospinal fluid (CSF) drainage, and many other factors. As such, there is a need for updated intraoperative information that accurately reflects intraoperative conditions. Since 1982, intraoperative ultrasound has allowed neurosurgeons to craft and update operative plans without ionizing radiation exposure or major workflow interruption. Continued evolution of ultrasound technology since its introduction has resulted in superior imaging quality, smaller probes, and more seamless integration with neuronavigation systems. Furthermore, the introduction of related imaging modalities, such as 3-dimensional ultrasound, contrast-enhanced ultrasound, high-frequency ultrasound, and ultrasound elastography have dramatically expanded the options available to the neurosurgeon intraoperatively. In the context of these advances, we review the current state, potential, and challenges of intraoperative ultrasound for brain tumor resection. We begin by evaluating these ultrasound technologies and their relative advantages and disadvantages. We then review three specific applications of these ultrasound technologies to brain tumor resection: (1) intraoperative navigation, (2) assessment of extent of resection, and (3) brain shift monitoring and compensation. We conclude by identifying opportunities for future directions in the development of ultrasound technologies. PMID:27541694

Computational Modeling for Enhancing Soft Tissue Image Guided Surgery: An Application in Neurosurgery.

PubMed

Miga, Michael I

2016-01-01

With the recent advances in computing, the opportunities to translate computational models to more integrated roles in patient treatment are expanding at an exciting rate. One area of considerable development has been directed towards correcting soft tissue deformation within image guided neurosurgery applications. This review captures the efforts that have been undertaken towards enhancing neuronavigation by the integration of soft tissue biomechanical models, imaging and sensing technologies, and algorithmic developments. In addition, the review speaks to the evolving role of modeling frameworks within surgery and concludes with some future directions beyond neurosurgical applications.

Minimally invasive trans-portal resection of deep intracranial lesions.

PubMed

Raza, S M; Recinos, P F; Avendano, J; Adams, H; Jallo, G I; Quinones-Hinojosa, A

2011-02-01

The surgical management of deep intra-axial lesions still requires microsurgical approaches that utilize retraction of deep white matter to obtain adequate visualization. We report our experience with a new tubular retractor system, designed specifically for intracranial applications, linked with frameless neuronavigation for a cohort of intraventricular and deep intra-axial tumors. The ViewSite Brain Access System (Vycor, Inc) was used in a series of 9 adult and pediatric patients with a variety of pathologies. Histological diagnoses either resected or biopsied with the system included: colloid cyst, DNET, papillary pineal tumor, anaplastic astrocytoma, toxoplasmosis and lymphoma. The locations of the lesions approached include: lateral ventricle, basal ganglia, pulvinar/posterior thalamus and insular cortex. Post-operative imaging was assessed to determine extent of resection and extent of white matter damage along the surgical trajectory (based on T (2)/FLAIR and diffusion restriction/ADC signal). Satisfactory resection or biopsy was obtained in all patients. Radiographic analysis demonstrated evidence of white matter damage along the surgical trajectory in one patient. None of the patients experienced neurological deficits as a result of white matter retraction/manipulation. Based on a retrospective review of our experience, we feel that this access system, when used in conjunction with frameless neuronavigational systems, provides adequate visualization for tumor resection while permitting the use of standard microsurgical techniques through minimally invasive craniotomies. Our initial data indicate that this system may minimize white matter injury, but further studies are necessary. © Georg Thieme Verlag KG Stuttgart · New York.

Use of a minimally invasive tubular retraction system for deep-seated tumors in pediatric patients.

PubMed

Recinos, Pablo F; Raza, Shaan M; Jallo, George I; Recinos, Violette Renard

2011-05-01

Microsurgical removal is the preferred treatment for most deep-seated, intraaxial tumors in the pediatric population. The feasibility of surgery as an option has improved with advances in surgical technology and technique. Tubular retractors disperse retraction forces over a greater surface area than do conventional retractors, which can lower the risk of ischemic complications. The authors describe their experience utilizing a new tubular retractor system specifically designed for cranial applications in conjunction with frameless neuronavigation. The Vycor ViewSite retractor was used in 4 pediatric patients (ages 15 months and 9, 10, and 16 years) with deep-seated intraaxial tumors. The lesions included a papillary tumor of the pineal region, a low-grade astrocytoma in the occipital lobe, a dysembryoplastic neuroepithelial tumor arising from the basal ganglia, and an intraventricular low-grade glioma. The extent of white matter damage along the surgical trajectory (based on T2 or FLAIR and diffusion restriction/apparent diffusion coefficient signals) and the extent of resection were assessed on postoperative imaging. Satisfactory resection or biopsy was achieved in all patients. A comparison of pre- and postoperative MR imaging studies revealed evidence of white matter damage along the surgical trajectory in 1 patient. None of the patients demonstrated new neurological deficits postoperatively. Obtaining surgical access to deep-seated, intraaxial tumors is challenging. In this small series of pediatric patients, the combination of the ViewSite tubular retractor and frameless neuronavigation facilitated the surgical approach. The combination of these technologies adds to the armamentarium to safely approach tumors in deep locations.

Augmented reality in neurosurgery: a systematic review.

PubMed

Meola, Antonio; Cutolo, Fabrizio; Carbone, Marina; Cagnazzo, Federico; Ferrari, Mauro; Ferrari, Vincenzo

2017-10-01

Neuronavigation has become an essential neurosurgical tool in pursuing minimal invasiveness and maximal safety, even though it has several technical limitations. Augmented reality (AR) neuronavigation is a significant advance, providing a real-time updated 3D virtual model of anatomical details, overlaid on the real surgical field. Currently, only a few AR systems have been tested in a clinical setting. The aim is to review such devices. We performed a PubMed search of reports restricted to human studies of in vivo applications of AR in any neurosurgical procedure using the search terms "Augmented reality" and "Neurosurgery." Eligibility assessment was performed independently by two reviewers in an unblinded standardized manner. The systems were qualitatively evaluated on the basis of the following: neurosurgical subspecialty of application, pathology of treated lesions and lesion locations, real data source, virtual data source, tracking modality, registration technique, visualization processing, display type, and perception location. Eighteen studies were included during the period 1996 to September 30, 2015. The AR systems were grouped by the real data source: microscope (8), hand- or head-held cameras (4), direct patient view (2), endoscope (1), and X-ray fluoroscopy (1) head-mounted display (1). A total of 195 lesions were treated: 75 (38.46 %) were neoplastic, 77 (39.48 %) neurovascular, and 1 (0.51 %) hydrocephalus, and 42 (21.53 %) were undetermined. Current literature confirms that AR is a reliable and versatile tool when performing minimally invasive approaches in a wide range of neurosurgical diseases, although prospective randomized studies are not yet available and technical improvements are needed.

Endoscopic endonasal trans-sphenoid surgery of pituitary adenoma

PubMed Central

Yadav, YR; Sachdev, S; Parihar, V; Namdev, H; Bhatele, PR

2012-01-01

Endoscopic endonasal trans-sphenoid surgery (EETS) is increasingly used for pituitary lesions. Pre-operative CT and MRI scans and peroperative endoscopic visualization can provide useful anatomical information. EETS is indicated in sellar, suprasellar, intraventricular, retro-infundibular, and invasive tumors. Recurrent and residual lesions, pituitary apoplexy and empty sella syndrome can be managed by EETS. Modern neuronavigation techniques, ultrasonic aspirators, ultrasonic bone curette can add to the safety. The binostril approach provides a wider working area. High definition camera is much superior to three-chip camera. Most of the recent reports favor EETS in terms of safety, quality of life and tumor resection, hospital stay, better endocrinological, and visual outcome as compared to the microscopic technique. Nasal symptoms, blood loss, operating time are less in EETS. Various naso-septal flaps and other techniques of CSF leak repair could help reduce complications. Complications can be further reduced after achieving the learning curve, good understanding of limitations with proper patient selection. Use of neuronavigation, proper post-operative care of endocrine function, establishing pituitary center of excellence and more focused residency and endoscopic fellowship training could improve results. The faster and safe transition from microscopic to EETS can be done by the team concept of neurosurgeon/otolaryngologist, attending hands on cadaveric dissection, practice on models, and observation of live surgeries. Conversion to a microscopic or endoscopic-assisted approach may be required in selected patients. Multi-modality treatment could be required in giant and invasive tumors. EETS appears to be a better surgical option in most pituitary adenoma. PMID:23188987

Predictors of response to repetitive transcranial magnetic stimulation (rTMS) in the treatment of major depressive disorder.

PubMed

Beuzon, G; Timour, Q; Saoud, M

2017-02-01

Repetitive transcranial magnetic stimulation (rTMS), based on the principle of electromagnetic induction, consists of applying series of magnetic impulses to the cerebral cortex so as to modulate neurone activity in a target zone. This technique, still experimental, could prove promising in the field of psychiatry, in particular for the treatment of major depressive disorder. It is important for the clinician to be able to assess the response potential of a given patient to rTMS, and this among other things requires relevant predictive factors to be available. This review of the literature aims to determine and analyse reported predictive factors for therapeutic response to rTMS treatment in major depressive disorder. Different parameters are studied, in particular age, the severity of the depressive episode, psychological dimensions, genetic factors, cerebral blood flows via cerebral imagery, and neuronavigation. The factors found to be associated with better therapeutic response were young age, low level of severity of the depressive episode, motor threshold intensity over 100%, more than 1000 stimulations per session, more than 10 days treatment, L/L genotype on the 5-HTTLPR transporter gene, C/C homozygosity on the promotor regions of the 5-HT1A receptor gene, Val/Val homozygosity on the BDNF gene, cordance analyses by EEG, and finally the accurate localisation provided by neuronavigation. The authors conclude that investigations in larger patient samples are required in the future, and that the work already achieved should provide lines of approach for the coming experimental studies. Copyright © 2016 L'Encéphale, Paris. Published by Elsevier Masson SAS. All rights reserved.

Intraoperative optical biopsy for brain tumors using spectro-lifetime properties of intrinsic fluorophores

NASA Astrophysics Data System (ADS)

Vasefi, Fartash; Kittle, David S.; Nie, Zhaojun; Falcone, Christina; Patil, Chirag G.; Chu, Ray M.; Mamelak, Adam N.; Black, Keith L.; Butte, Pramod V.

2016-04-01

We have developed and tested a system for real-time intra-operative optical identification and classification of brain tissues using time-resolved fluorescence spectroscopy (TRFS). A supervised learning algorithm using linear discriminant analysis (LDA) employing selected intrinsic fluorescence decay temporal points in 6 spectral bands was employed to maximize statistical significance difference between training groups. The linear discriminant analysis on in vivo human tissues obtained by TRFS measurements (N = 35) were validated by histopathologic analysis and neuronavigation correlation to pre-operative MRI images. These results demonstrate that TRFS can differentiate between normal cortex, white matter and glioma.

Multimodal Navigation in Endoscopic Transsphenoidal Resection of Pituitary Tumors Using Image-Based Vascular and Cranial Nerve Segmentation: A Prospective Validation Study.

PubMed

Dolati, Parviz; Eichberg, Daniel; Golby, Alexandra; Zamani, Amir; Laws, Edward

2016-11-01

Transsphenoidal surgery (TSS) is the most common approach for the treatment of pituitary tumors. However, misdirection, vascular damage, intraoperative cerebrospinal fluid leakage, and optic nerve injuries are all well-known complications, and the risk of adverse events is more likely in less-experienced hands. This prospective study was conducted to validate the accuracy of image-based segmentation coupled with neuronavigation in localizing neurovascular structures during TSS. Twenty-five patients with a pituitary tumor underwent preoperative 3-T magnetic resonance imaging (MRI), and MRI images loaded into the navigation platform were used for segmentation and preoperative planning. After patient registration and subsequent surgical exposure, each segmented neural or vascular element was validated by manual placement of the navigation probe or Doppler probe on or as close as possible to the target. Preoperative segmentation of the internal carotid artery and cavernous sinus matched with the intraoperative endoscopic and micro-Doppler findings in all cases. Excellent correspondence between image-based segmentation and the endoscopic view was also evident at the surface of the tumor and at the tumor-normal gland interfaces. Image guidance assisted the surgeons in localizing the optic nerve and chiasm in 64% of cases. The mean accuracy of the measurements was 1.20 ± 0.21 mm. Image-based preoperative vascular and neural element segmentation, especially with 3-dimensional reconstruction, is highly informative preoperatively and potentially could assist less-experienced neurosurgeons in preventing vascular and neural injury during TSS. In addition, the accuracy found in this study is comparable to previously reported neuronavigation measurements. This preliminary study is encouraging for future prospective intraoperative validation with larger numbers of patients. Copyright © 2016 Elsevier Inc. All rights reserved.

Multimodal navigated skull base tumor resection using image-based vascular and cranial nerve segmentation: A prospective pilot study

PubMed Central

Dolati, Parviz; Gokoglu, Abdulkerim; Eichberg, Daniel; Zamani, Amir; Golby, Alexandra; Al-Mefty, Ossama

2015-01-01

Background: Skull base tumors frequently encase or invade adjacent normal neurovascular structures. For this reason, optimal tumor resection with incomplete knowledge of patient anatomy remains a challenge. Methods: To determine the accuracy and utility of image-based preoperative segmentation in skull base tumor resections, we performed a prospective study. Ten patients with skull base tumors underwent preoperative 3T magnetic resonance imaging, which included thin section three-dimensional (3D) space T2, 3D time of flight, and magnetization-prepared rapid acquisition gradient echo sequences. Imaging sequences were loaded in the neuronavigation system for segmentation and preoperative planning. Five different neurovascular landmarks were identified in each case and measured for accuracy using the neuronavigation system. Each segmented neurovascular element was validated by manual placement of the navigation probe, and errors of localization were measured. Results: Strong correspondence between image-based segmentation and microscopic view was found at the surface of the tumor and tumor-normal brain interfaces in all cases. The accuracy of the measurements was 0.45 ± 0.21 mm (mean ± standard deviation). This information reassured the surgeon and prevented vascular injury intraoperatively. Preoperative segmentation of the related cranial nerves was possible in 80% of cases and helped the surgeon localize involved cranial nerves in all cases. Conclusion: Image-based preoperative vascular and neural element segmentation with 3D reconstruction is highly informative preoperatively and could increase the vigilance of neurosurgeons for preventing neurovascular injury during skull base surgeries. Additionally, the accuracy found in this study is superior to previously reported measurements. This novel preliminary study is encouraging for future validation with larger numbers of patients. PMID:26674155

Multimodal navigated skull base tumor resection using image-based vascular and cranial nerve segmentation: A prospective pilot study.

PubMed

Dolati, Parviz; Gokoglu, Abdulkerim; Eichberg, Daniel; Zamani, Amir; Golby, Alexandra; Al-Mefty, Ossama

2015-01-01

Skull base tumors frequently encase or invade adjacent normal neurovascular structures. For this reason, optimal tumor resection with incomplete knowledge of patient anatomy remains a challenge. To determine the accuracy and utility of image-based preoperative segmentation in skull base tumor resections, we performed a prospective study. Ten patients with skull base tumors underwent preoperative 3T magnetic resonance imaging, which included thin section three-dimensional (3D) space T2, 3D time of flight, and magnetization-prepared rapid acquisition gradient echo sequences. Imaging sequences were loaded in the neuronavigation system for segmentation and preoperative planning. Five different neurovascular landmarks were identified in each case and measured for accuracy using the neuronavigation system. Each segmented neurovascular element was validated by manual placement of the navigation probe, and errors of localization were measured. Strong correspondence between image-based segmentation and microscopic view was found at the surface of the tumor and tumor-normal brain interfaces in all cases. The accuracy of the measurements was 0.45 ± 0.21 mm (mean ± standard deviation). This information reassured the surgeon and prevented vascular injury intraoperatively. Preoperative segmentation of the related cranial nerves was possible in 80% of cases and helped the surgeon localize involved cranial nerves in all cases. Image-based preoperative vascular and neural element segmentation with 3D reconstruction is highly informative preoperatively and could increase the vigilance of neurosurgeons for preventing neurovascular injury during skull base surgeries. Additionally, the accuracy found in this study is superior to previously reported measurements. This novel preliminary study is encouraging for future validation with larger numbers of patients.

Intraoperative confocal microscopy in the visualization of 5-aminolevulinic acid fluorescence in low-grade gliomas.

PubMed

Sanai, Nader; Snyder, Laura A; Honea, Norissa J; Coons, Stephen W; Eschbacher, Jennifer M; Smith, Kris A; Spetzler, Robert F

2011-10-01

Greater extent of resection (EOR) for patients with low-grade glioma (LGG) corresponds with improved clinical outcome, yet remains a central challenge to the neurosurgical oncologist. Although 5-aminolevulinic acid (5-ALA)-induced tumor fluorescence is a strategy that can improve EOR in gliomas, only glioblastomas routinely fluoresce following 5-ALA administration. Intraoperative confocal microscopy adapts conventional confocal technology to a handheld probe that provides real-time fluorescent imaging at up to 1000× magnification. The authors report a combined approach in which intraoperative confocal microscopy is used to visualize 5-ALA tumor fluorescence in LGGs during the course of microsurgical resection. Following 5-ALA administration, patients with newly diagnosed LGG underwent microsurgical resection. Intraoperative confocal microscopy was conducted at the following points: 1) initial encounter with the tumor; 2) the midpoint of tumor resection; and 3) the presumed brain-tumor interface. Histopathological analysis of these sites correlated tumor infiltration with intraoperative cellular tumor fluorescence. Ten consecutive patients with WHO Grades I and II gliomas underwent microsurgical resection with 5-ALA and intraoperative confocal microscopy. Macroscopic tumor fluorescence was not evident in any patient. However, in each case, intraoperative confocal microscopy identified tumor fluorescence at a cellular level, a finding that corresponded to tumor infiltration on matched histological analyses. Intraoperative confocal microscopy can visualize cellular 5-ALA-induced tumor fluorescence within LGGs and at the brain-tumor interface. To assess the clinical value of 5-ALA for high-grade gliomas in conjunction with neuronavigation, and for LGGs in combination with intraoperative confocal microscopy and neuronavigation, a Phase IIIa randomized placebo-controlled trial (BALANCE) is underway at the authors' institution.

Continuous physical examination during subcortical resection in awake craniotomy patients: Its usefulness and surgical outcome.

PubMed

Bunyaratavej, Krishnapundha; Sangtongjaraskul, Sunisa; Lerdsirisopon, Surunchana; Tuchinda, Lawan

2016-08-01

To evaluate the value of physical examination as a monitoring tool during subcortical resection in awake craniotomy patients and surgical outcomes. Authors reviewed medical records of patients underwent awake craniotomy with continuous physical examination for pathology adjacent to the eloquent area. Between January 2006 and August 2015, there were 37 patients underwent awake craniotomy with continuous physical examination. Pathology was located in the left cerebral hemisphere in 28 patients (75.7%). Thirty patients (81.1%) had neuroepithelial tumors. Degree of resections were defined as total, subtotal, and partial in 16 (43.2%), 11 (29.7%) and 10 (27.0%) patients, respectively. Median follow up duration was 14 months. The reasons for termination of subcortical resection were divided into 3 groups as follows: 1) by anatomical landmark with the aid of neuronavigation in 20 patients (54%), 2) by reaching subcortical stimulation threshold in 8 patients (21.6%), and 3) by abnormal physical examination in 9 patients (24.3%). Among these 3 groups, there were statistically significant differences in the intraoperative (p=0.002) and early postoperative neurological deficit (p=0.005) with the lowest deficit in neuronavigation group. However, there were no differences in neurological outcome at later follow up (3-months p=0.103; 6-months p=0.285). There were no differences in the degree of resection among the groups. Continuous physical examination has shown to be of value as an additional layer of monitoring of subcortical white matter during resection and combining several methods may help increase the efficacy of mapping and monitoring of subcortical functions. Copyright © 2016 Elsevier B.V. All rights reserved.

First Application of 7-T Magnetic Resonance Imaging in Endoscopic Endonasal Surgery of Skull Base Tumors.

PubMed

Barrett, Thomas F; Dyvorne, Hadrien A; Padormo, Francesco; Pawha, Puneet S; Delman, Bradley N; Shrivastava, Raj K; Balchandani, Priti

2017-07-01

Successful endoscopic endonasal surgery for the resection of skull base tumors is reliant on preoperative imaging to delineate pathology from the surrounding anatomy. The increased signal-to-noise ratio afforded by 7-T MRI can be used to increase spatial and contrast resolution, which may lend itself to improved imaging of the skull base. In this study, we apply a 7-T imaging protocol to patients with skull base tumors and compare the images with clinical standard of care. Images were acquired at 7 T on 11 patients with skull base lesions. Two neuroradiologists evaluated clinical 1.5-, 3-, and 7-T scans for detection of intracavernous cranial nerves and internal carotid artery (ICA) branches. Detection rates were compared. Images were used for surgical planning and uploaded to a neuronavigation platform and used to guide surgery. Image analysis yielded improved detection rates of cranial nerves and ICA branches at 7 T. The 7-T images were successfully incorporated into preoperative planning and intraoperative neuronavigation. Our study represents the first application of 7-T MRI to the full neurosurgical workflow for endoscopic endonasal surgery. We detected higher rates of cranial nerves and ICA branches at 7-T MRI compared with 3- and 1.5-T MRI, and found that integration of 7 T into surgical planning and guidance was feasible. These results suggest a potential for 7-T MRI to reduce surgical complications. Future studies comparing standardized 7-, 3-, and 1.5-T MRI protocols in a larger number of patients are warranted to determine the relative benefit of 7-T MRI for endonasal endoscopic surgical efficacy. Copyright © 2017 Elsevier Inc. All rights reserved.

First Application of 7T Magnetic Resonance Imaging in Endoscopic Endonasal Surgery of Skull Base Tumors

PubMed Central

Barrett, Thomas F; Dyvorne, Hadrien A; Padormo, Francesco; Pawha, Puneet S; Delman, Bradley N; Shrivastava, Raj K; Balchandani, Priti

2018-01-01

Background Successful endoscopic endonasal surgery for the resection of skull base tumors is reliant on preoperative imaging to delineate pathology from the surrounding anatomy. The increased signal-to-noise ratio afforded by 7T MRI can be used to increase spatial and contrast resolution, which may lend itself to improved imaging of skull base. In this study, we apply a 7T imaging protocol to patients with skull base tumors and compare the images to clinical standard of care. Methods Images were acquired at 7T on 11 patients with skull base lesions. Two neuroradiologists evaluated clinical 1.5T, 3T, and 7T scans for detection of intracavernous cranial nerves and ICA branches. Detection rates were compared. Images were utilized for surgical planning and uploaded to a neuronavigation platform and used to guide surgery. Results Image analysis yielded improved detection rates of cranial nerves and ICA branches at 7T. 7T images were successfully incorporated into preoperative planning and intraoperative neuronavigation. Conclusion Our study represents the first application of 7T MRI to the full neurosurgical workflow for endoscopic endonasal surgery. We detected higher rates of cranial nerves and ICA branches at 7T MRI compared to 3T and 1.5 T, and found that integration of 7T into surgical planning and guidance was feasible. These results suggest a potential for 7T MRI to reduce surgical complications. Future studies comparing standardized 7T, 3T, and 1.5 T MRI protocols in a larger number of patients are warranted to determine the relative benefit of 7T MRI for endonasal endoscopic surgical efficacy. PMID:28359922

Multimodal Approach for Radical Excision of Focal Cortical Dysplasia by Combining Advanced Magnetic Resonance Imaging Data to Intraoperative Ultrasound, Electrocorticography, and Cortical Stimulation: A Preliminary Experience.

PubMed

Tringali, Giovanni; Bono, Beatrice; Dones, Ivano; Cordella, Roberto; Didato, Giuseppe; Villani, Flavio; Prada, Francesco

2018-05-01

Type II focal cortical dysplasia is the most common malformation of cortical development associated with drug resistant epilepsy and susceptible to surgical resection. Although, at present, advanced imaging modalities are capable of detecting most cortical disorders, it is still a challenge for the surgeon to visualize them intraoperatively. The lack of direct identification between normal brain and subtle dysplastic tissue may explain the poor results in terms of being seizure-free versus other forms of epilepsy. The aim of this study is to compare magnetic resonance imaging (MRI) and intraoperative ultrasound-guided neuronavigation, along with cortical stimulation and acute electrocorticography, as a multimodal surgical approach to cortical dysplasia's tailored resection. Six consecutive patients with type II cortical dysplasia underwent epilepsy surgery by means of MRI/intraoperative ultrasound-guided neuronavigation. Intraoperative cortical stimulation of sensory/motor cortex was performed to localize cortical eloquent areas. Acute electrocorticography was used to identify epileptogenic tissue. These findings were correlated to real-time ultrasound imaging to establish the extent of the resection. Intraoperative ultrasound depicted cortical dysplasias at a higher resolution and accuracy than MRI. Therefore it maximized the extent of the resection. Both postoperative MRIs and pathology documented the extent of the resection in all patients. Seizure-freedom was achieved in 5 cases (Engel class IA), and in 1 patient it was classified as Engel class IB. No postoperative neurological deficits were observed. These results strongly suggest feasibility of ultrasound-guided resection of focal cortical dysplasia. Providing high resolution and accuracy, it allows an easy, real-time discrimination between normal and dysplastic brain. Copyright © 2018 Elsevier Inc. All rights reserved.

How to include the variability of TMS responses in simulations: a speech mapping case study

NASA Astrophysics Data System (ADS)

De Geeter, N.; Lioumis, P.; Laakso, A.; Crevecoeur, G.; Dupré, L.

2016-11-01

When delivered over a specific cortical site, TMS can temporarily disrupt the ongoing process in that area. This allows mapping of speech-related areas for preoperative evaluation purposes. We numerically explore the observed variability of TMS responses during a speech mapping experiment performed with a neuronavigation system. We selected four cases with very small perturbations in coil position and orientation. In one case (E) a naming error occurred, while in the other cases (NEA, B, C) the subject appointed the images as smoothly as without TMS. A realistic anisotropic head model was constructed of the subject from T1-weighted and diffusion-weighted MRI. The induced electric field distributions were computed, associated to the coil parameters retrieved from the neuronavigation system. Finally, the membrane potentials along relevant white matter fibre tracts, extracted from DTI-based tractography, were computed using a compartmental cable equation. While only minor differences could be noticed between the induced electric field distributions of the four cases, computing the corresponding membrane potentials revealed different subsets of tracts were activated. A single tract was activated for all coil positions. Another tract was only triggered for case E. NEA induced action potentials in 13 tracts, while NEB stimulated 11 tracts and NEC one. The calculated results are certainly sensitive to the coil specifications, demonstrating the observed variability in this study. However, even though a tract connecting Broca’s with Wernicke’s area is only triggered for the error case, further research is needed on other study cases and on refining the neural model with synapses and network connections. Case- and subject-specific modelling that includes both electromagnetic fields and neuronal activity enables demonstration of the variability in TMS experiments and can capture the interaction with complex neural networks.

The future of spine surgery: New horizons in the treatment of spinal disorders

PubMed Central

Kazemi, Noojan; Crew, Laura K.; Tredway, Trent L.

2013-01-01

Background and Methods: As with any evolving surgical discipline, it is difficult to predict the future of the practice and science of spine surgery. In the last decade, there have been dramatic developments in both the techniques as well as the tools employed in the delivery of better outcomes to patients undergoing such surgery. In this article, we explore four specific areas in spine surgery: namely the role of minimally invasive spine surgery; motion preservation; robotic-aided surgery and neuro-navigation; and the use of biological substances to reduce the number of traditional and revision spine surgeries. Results: Minimally invasive spine surgery has flourished in the last decade with an increasing amount of surgeries being performed for a wide variety of degenerative, traumatic, and neoplastic processes. Particular progress in the development of a direct lateral approach as well as improvement of tubular retractors has been achieved. Improvements in motion preservation techniques have led to a significant number of patients achieving arthroplasty where fusion was the only option previously. Important caveats to the indications for arthroplasty are discussed. Both robotics and neuro-navigation have become further refined as tools to assist in spine surgery and have been demonstrated to increase accuracy in spinal instrumentation placement. There has much debate and refinement in the use of biologically active agents to aid and augment function in spine surgery. Biological agents targeted to the intervertebral disc space could increase function and halt degeneration in this anatomical region. Conclusions: Great improvements have been achieved in developing better techniques and tools in spine surgery. It is envisaged that progress in the four focus areas discussed will lead to better outcomes and reduced burdens on the future of both our patients and the health care system. PMID:23653885

Accuracy of neuro-navigated cranial screw placement using optical surface imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Jakubovic, Raphael; Gupta, Shuarya; Guha, Daipayan; Mainprize, Todd; Yang, Victor X. D.

2017-02-01

Cranial neurosurgical procedures are especially delicate considering that the surgeon must localize the subsurface anatomy with limited exposure and without the ability to see beyond the surface of the surgical field. Surgical accuracy is imperative as even minor surgical errors can cause major neurological deficits. Traditionally surgical precision was highly dependent on surgical skill. However, the introduction of intraoperative surgical navigation has shifted the paradigm to become the current standard of care for cranial neurosurgery. Intra-operative image guided navigation systems are currently used to allow the surgeon to visualize the three-dimensional subsurface anatomy using pre-acquired computed tomography (CT) or magnetic resonance (MR) images. The patient anatomy is fused to the pre-acquired images using various registration techniques and surgical tools are typically localized using optical tracking methods. Although these techniques positively impact complication rates, surgical accuracy is limited by the accuracy of the navigation system and as such quantification of surgical error is required. While many different measures of registration accuracy have been presented true navigation accuracy can only be quantified post-operatively by comparing a ground truth landmark to the intra-operative visualization. In this study we quantified the accuracy of cranial neurosurgical procedures using a novel optical surface imaging navigation system to visualize the three-dimensional anatomy of the surface anatomy. A tracked probe was placed on the screws of cranial fixation plates during surgery and the reported position of the centre of the screw was compared to the co-ordinates of the post-operative CT or MR images, thus quantifying cranial neurosurgical error.

High-resolution imaging of the central nervous system: how novel imaging methods combined with navigation strategies will advance patient care.

PubMed

Farooq, Hamza; Genis, Helen; Alarcon, Joseph; Vuong, Barry; Jivraj, Jamil; Yang, Victor X D; Cohen-Adad, Julien; Fehlings, Michael G; Cadotte, David W

2015-01-01

This narrative review captures a subset of recent advances in imaging of the central nervous system. First, we focus on improvements in the spatial and temporal profile afforded by optical coherence tomography, fluorescence-guided surgery, and Coherent Anti-Stokes Raman Scattering Microscopy. Next, we highlight advances in the generation and uses of imaging-based atlases and discuss how this will be applied to specific clinical situations. To conclude, we discuss how these and other imaging tools will be combined with neuronavigation techniques to guide surgeons in the operating room. Collectively, this work aims to highlight emerging biomedical imaging strategies that hold potential to be a valuable tool for both clinicians and researchers in the years to come. © 2015 Elsevier B.V. All rights reserved.

Surgical treatment of insular tumours with tractography, functional magnetic resonance imaging, transcranial electrical stimulation and direct subcortical stimulation support.

PubMed

Majchrzak, Krzysztof; Bobek-Billewicz, Barbara; Tymowski, Michał; Adamczyk, Piotr; Majchrzak, Hneryk; Ladziński, Piotr

2011-01-01

Surgical treatment of insular tumours carries significant risks of limb paresis or speech disturbances due to their localization. The development of intraoperative neuromonitoring techniques that involve evoked motor potentials induced via both direct and transcranial cortical electrical stimulation as well as direct subcortical white matter stimulation, intraoperative application of preoperative tractography and functional magnetic resonance imaging (fMRI) in conjunction with neuronavigation resulted in significant reduction of postoperative disabilities that enabled widening of indications for surgical treatment. The aim of this study was to present the authors' own experience with surgical treatment of insular gliomas. Our cohort comprises 30 patients with insular gliomas treated at the Department of Neurosurgery in Sosnowiec. Clinical symptoms included sensorimotor partial seizures in 86.6%; generalized seizures in 23.3%; persistent headaches in 16.6% and hemiparesis in 6.6%. All the patients were operated on with intraoperative neuromonitoring that included transcranial cortical stimulation, direct subcortical white matter stimulation as well as tractography and fMRI concurrently with neuronavigation. The analysis in-cluded postoperative neurological evaluation along with the assessment of the radicalism of resection evaluated based on postoperative MRI. Postoperatively, four patients had permanent hemiparesis (13.3%); importantly, two out of those patients had preoperative deficits (6.6%). Persistent speech disturbances were present in four patients (13.3%). Partial sensorimotor seizures were noted in two patients (6.6%). Seizures in the other patients receded. Intraoperative transcranial electrical stimulation as well as direct subcortical white matter stimulation along with tractography (DTI) and fMRI facilitated gross total resection of insular gliomas in 53.5%, subtotal in 13.3% and partial resection in 33.1%. Implementation of TES, direct subcortical

Navigation-assisted trans-inferotemporal cortex selective amygdalohippocampectomy for mesial temporal lobe epilepsy; preserving the temporal stem.

PubMed

Kishima, Haruhiko; Kato, Amami; Oshino, Satoru; Tani, Naoki; Maruo, Tomoyuki; Khoo, Hui Ming; Yanagisawa, Takufumi; Edakawa, Kotaro; Kobayashi, Maki; Tanaka, Masataka; Hosomi, Koichi; Hirata, Masayuki; Yoshimine, Toshiki

2017-03-01

Selective amygdalohippocampectomy (SAH) can be used to obtain satisfactory seizure control in patients with mesial temporal lobe epilepsy (MTLE). Several SAH procedures have been reported to achieve satisfactory outcomes for seizure control, but none yield fully satisfactory outcomes for memory function. We hypothesized that preserving the temporal stem might play an important role. To preserve the temporal stem, we developed a minimally invasive surgical procedure, 'neuronavigation-assisted trans-inferotemporal cortex SAH' (TITC-SAH). TITC-SAH was performed in 23 patients with MTLE (MTLE on the language-non-dominant hemisphere, n = 11). The inferior horn of the lateral ventricle was approached via the inferior or middle temporal gyrus along the inferior temporal sulcus under neuronavigation guidance. The hippocampus was dissected in a subpial manner and resected en bloc together with the parahippocampal gyrus. Seizure control at one year and memory function at 6 months postoperatively were evaluated. One year after TITC-SAH, 20 of the 23 patients were seizure-free (ILAE class 1), 2 were class 2, and 1 was class 3. Verbal memory improved significantly in 13 patients with a diagnosis of hippocampal sclerosis, for whom WMS-R scores were available both pre- and post-operatively. Improvements were seen regardless of whether the SAH was on the language-dominant or non-dominant hemisphere. No major complication was observed. Navigation-assisted TITC-SAH performed for MTLE offers a simple, minimally invasive procedure that appears to yield excellent outcomes in terms of seizure control and preservation of memory function, because this procedure does not damage the temporal stem. TITC-SAH should be one of the feasible surgical procedures for MTLE. SAH: Amygdalohippocampectomy; MTLE: Mesial temporal lobe epilepsy (MTLE); TITC-SAH: Ttrans-inferotemporal cortex SAH; ILAE: International League Against Epilepsy (ILAE); MRI: Magnetic resonance imaging; EEG

A neurosurgical presentation of patent foramen ovale with atrial septal aneurysm

PubMed Central

Walsh, Katie; Kaliaperumal, Chandrasekaran; Wyse, Gerry; Kaar, George

2011-01-01

We describe a case of cerebral abscess in a 53-year-old lady with a background of congenital heart defect. She has an atrial septal defect with atrial septal aneurysm, which remained undiagnosed until this clinical presentation. She presented with a short history of right-sided hemiplaegia and neuroimaging revealed a heterogeneous lesion in the left frontoparietal region. Neuronavigation-guided left frontoparietal craniotomy was performed to debulk the lesion and preoperatively frank pus was drained, which grew Streptococcus constellatus. She was successfully treated with antibiotics for 6 weeks and her clinical condition improved. We believe that the patients’ previous dental extraction has possibly resulted in a paradoxical embolism through the atrial septal defect bypassing the pulmonary circulation. The MRI scan picture was misleading, as it was initially thought to be a high-grade brain tumour. PMID:22689610

Intraoperative imaging technology to maximise extent of resection for glioma.

PubMed

Jenkinson, Michael D; Barone, Damiano Giuseppe; Bryant, Andrew; Vale, Luke; Bulbeck, Helen; Lawrie, Theresa A; Hart, Michael G; Watts, Colin

2018-01-22

Extent of resection is considered to be a prognostic factor in neuro-oncology. Intraoperative imaging technologies are designed to help achieve this goal. It is not clear whether any of these sometimes very expensive tools (or their combination) should be recommended as standard care for people with brain tumours. We set out to determine if intraoperative imaging technology offers any advantage in terms of extent of resection over standard surgery and if any one technology was more effective than another. To establish the overall effectiveness and safety of intraoperative imaging technology in resection of glioma. To supplement this review of effects, we also wished to identify cost analyses and economic evaluations as part of a Brief Economic Commentary (BEC). We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 7, 2017), MEDLINE (1946 to June, week 4, 2017), and Embase (1980 to 2017, week 27). We searched the reference lists of all identified studies. We handsearched two journals, the Journal of Neuro-Oncology and Neuro-oncology, from 1991 to 2017, including all conference abstracts. We contacted neuro-oncologists, trial authors, and manufacturers regarding ongoing and unpublished trials. Randomised controlled trials evaluating people of all ages with presumed new or recurrent glial tumours (of any location or histology) from clinical examination and imaging (computed tomography (CT) or magnetic resonance imaging (MRI), or both). Additional imaging modalities (e.g. positron emission tomography, magnetic resonance spectroscopy) were not mandatory. Interventions included intraoperative MRI (iMRI), fluorescence-guided surgery, ultrasound, and neuronavigation (with or without additional image processing, e.g. tractography). Two review authors independently assessed the search results for relevance, undertook critical appraisal according to known guidelines, and extracted data using a prespecified pro forma. We identified four randomised

The Supraorbital Keyhole Craniotomy through an Eyebrow Incision: Its Origins and Evolution

PubMed Central

Ormond, D. Ryan; Hadjipanayis, Costas G.

2013-01-01

In the modern era of neurosurgery, the use of the operative microscope, rigid rod-lens endoscope, and neuronavigation has helped to overcome some of the previous limitations of surgery due to poor lighting and anatomic localization available to the surgeon. Over the last thirty years, the supraorbital craniotomy and subfrontal approach through an eyebrow incision have been developed and refined to play a legitimate role in the armamentarium of the modern skull base neurosurgeon. With careful patient selection, the supraorbital “keyhole” approach offers a less invasive but still efficacious approach to a number of lesions along the subfrontal corridor. Well over 1000 cases have been reported in the literature utilizing this approach establishing its safety and efficacy. This paper discusses the nuances of this approach, including the benefits and limitations of its use described through our technique, review of the literature, and case illustration. PMID:23936644

Recent technological advances in pediatric brain tumor surgery.

PubMed

Zebian, Bassel; Vergani, Francesco; Lavrador, José Pedro; Mukherjee, Soumya; Kitchen, William John; Stagno, Vita; Chamilos, Christos; Pettorini, Benedetta; Mallucci, Conor

2017-01-01

X-rays and ventriculograms were the first imaging modalities used to localize intracranial lesions including brain tumors as far back as the 1880s. Subsequent advances in preoperative radiological localization included computed tomography (CT; 1971) and MRI (1977). Since then, other imaging modalities have been developed for clinical application although none as pivotal as CT and MRI. Intraoperative technological advances include the microscope, which has allowed precise surgery under magnification and improved lighting, and the endoscope, which has improved the treatment of hydrocephalus and allowed biopsy and complete resection of intraventricular, pituitary and pineal region tumors through a minimally invasive approach. Neuronavigation, intraoperative MRI, CT and ultrasound have increased the ability of the neurosurgeon to perform safe and maximal tumor resection. This may be facilitated by the use of fluorescing agents, which help define the tumor margin, and intraoperative neurophysiological monitoring, which helps identify and protect eloquent brain.

Navigated transcranial magnetic stimulation in preoperative planning for the treatment of motor area cavernous angiomas

PubMed Central

Paiva, Wellingson Silva; Fonoff, Erich Talamoni; Marcolin, Marco Antonio; Bor-Seng-Shu, Edson; Figueiredo, Eberval Gadelha; Teixeira, Manoel Jacobsen

2013-01-01

Since the introduction of microscopic techniques, radical surgery for cavernous angiomas has become a recommended treatment option. However, the treatment of motor area cavernous angioma represents a great challenge for the surgical team. Here, we describe an approach guided by frameless neuronavigation and preoperative functional mapping with transcranial magnetic stimulation (TMS), for surgical planning. We used TMS to map the motor cortex and its relationship with the angioma. We achieved complete resection of the lesions in the surgeries, while avoiding areas of motor response identified during the preoperative mapping. We verified the complete control of seizures (Engel class 1A) in the patients with previous refractory epilepsy. Postsurgery, one patient was seizure-free without medication, and two patients required only one medication for seizure control. Thus, navigated TMS appears to be a useful tool, in preoperative planning for cavernous angiomas of the motor area. PMID:24353424

Electromagnetic navigation-guided neuroendoscopic removal of radiation-induced intraforniceal cavernoma as a late complication of medulloblastoma treatment.

PubMed

Liby, Petr; Zamecnik, J; Kyncl, M; Zackova, J; Tichy, M

2017-11-01

Medulloblastoma is the most frequent malignant brain tumour in children. Radiation-induced cavernous haemangiomas (RICHs) are a known late complication of radiation exposure, especially in young children. We present a patient who underwent subtotal resection of posterior fossa medulloblastoma with subsequent chemotherapy and radiotherapy at the age of 10 years. A new lesion in the region of the left foramen of Monro appeared 16 years later. Based on the imaging results, metastasis or radiation-induced cavernoma was considered. The lesion had the same appearance on imaging as a rarely published intraventricular cavernoma of the foramen of Monro. Unlike the cavernoma of the foramen of Monro, this lesion was subependymal and intraforniceal. Using electromagnetic navigation and neuroendoscopy, the lesion was completely removed. Histopathological examination revealed a cavernous haemangioma. This is a unique case of intraforniceal paraforaminal cavernoma that was successfully removed endoscopically using electromagnetic neuronavigation and without neurological sequelae.

Resection of a Pediatric Thalamic Juvenile Pilocytic Astrocytoma with Whole Brain Tractography

PubMed Central

Weiner, Howard L

2017-01-01

The resection of deep-seated brain tumors has been associated with morbidity due to injury to critical neural structures during the approach. Recent technological advancements in navigation and stereotaxy, surgical planning, brain tractography and minimal-access brain ports present the opportunity to overcome such limitations. Here, we present the case of a pediatric patient with a left thalamic/midbrain juvenile pilocytic astrocytoma (JPA). The tumor displaced the corticospinal fibers posteriorly and resulted in hemiparesis. Using whole brain tractography to plan a corridor for the approach, neuronavigation, a tubular retractor and an exoscope for visualization, we obtained gross total resection of the tumor, while minimizing injury to white matter bundles, including the corticospinal fibers. We propose that surgical planning with whole brain tractography is essential for reducing morbidity while accessing deep-lying brain lesions via retractor tubes, by means of sparing critical fiber tracts. PMID:29234572

Occipital neuralgia secondary to unilateral atlantoaxial osteoarthritis: Case report and review of the literature.

PubMed

Guha, Daipayan; Mohanty, Chandan; Tator, Charles H; Shamji, Mohammed F

2015-01-01

Atlantoaxial osteoarthritis (AAOA), either in isolation or in the context of generalized peripheral or spinal arthritis, presents most commonly with neck pain and limitation of cervical rotational range of motion. Occipital neuralgia (ON) is only rarely attributed to AAOA, as fewer than 30 cases are described in the literature. A 64-year-old female presented with progressive incapacitating cervicalgia and occipital headaches, refractory to medications, and local anesthetic blocks. Computed tomography and magnetic resonance imaging studies documented advanced unilateral atlantoaxial arthrosis with osteophytic compression that dorsally displaced the associated C2 nerve root. Surgical decompression and atlantoaxial fusion achieved rapid and complete relief of neuralgia. Ultimately, postoperative spinal imaging revealed osseous union. Atlantoaxial arthrosis must be considered in the differential diagnosis of ON. Surgical treatment is effective for managing refractory cases. Intraoperative neuronavigation is also a useful adjunct to guide instrumentation and the intraoperative extent of bony decompression.

Efficient Blood-Brain Barrier Opening in Primates with Neuronavigation-Guided Ultrasound and Real-Time Acoustic Mapping.

PubMed

Wu, Shih-Ying; Aurup, Christian; Sanchez, Carlos Sierra; Grondin, Julien; Zheng, Wenlan; Kamimura, Hermes; Ferrera, Vincent P; Konofagou, Elisa E

2018-05-22

Brain diseases including neurological disorders and tumors remain under treated due to the challenge to access the brain, and blood-brain barrier (BBB) restricting drug delivery which, also profoundly limits the development of pharmacological treatment. Focused ultrasound (FUS) with microbubbles is the sole method to open the BBB noninvasively, locally, and transiently and facilitate drug delivery, while translation to the clinic is challenging due to long procedure, targeting limitations, or invasiveness of current systems. In order to provide rapid, flexible yet precise applications, we have designed a noninvasive FUS and monitoring system with the protocol tested in monkeys (from in silico preplanning and simulation, real-time targeting and acoustic mapping, to post-treatment assessment). With a short procedure (30 min) similar to current clinical imaging duration or radiation therapy, the achieved targeting (both cerebral cortex and subcortical structures) and monitoring accuracy was close to the predicted 2-mm lower limit. This system would enable rapid clinical transcranial FUS applications outside of the MRI system without a stereotactic frame, thereby benefiting patients especially in the elderly population.

Muscle Insertion Line as a Simple Landmark To Identify the Transverse Sinus When Neuronavigation Is Unavailable.

PubMed

Kivelev, Juri; Kivisaari, Riku; Niemelä, Mika; Hernesniemi, Juha

2016-10-01

Skull opening in occipital and suboccipital regions might be associated with risk of damage to the transverse venous sinus and the confluence of sinuses. We analyze the value of magnetic resonance (MR) imaging in localizing the venous sinuses in relation to the superior muscle insertion line (MIL) on the occipital bone. We retrospectively analyzed head MR images of 100 consecutive patients imaged for any reason from 1 January 2013. All MR images were interpreted by a radiologist (R.K.). The superior MIL was identified at the midline and on both midpupillar lines, which represent the most frequent sites of skin incision and craniotomy (median and lateral suboccipital craniotomy, respectively). Patients comprised 56 women (56%) and 44 men (44%). Their mean age was 54 (range 18-84) years. The muscles of the posterior skull were readily visible and clearly identified in both T1 and T2 images of all patients. Identification of the insertion zone and its relation to the venous structures was most readily made in the sagittal plane. We found that the upper muscle insertion line on occipital bone corresponds to the underlying venous sinus and can be used as a reliable anatomic landmark. We identified it in 100% of preoperative MR images of heads with an intact occiput. Copyright © 2016 Elsevier Inc. All rights reserved.

Nocardia farcinica brain abscess: epidemiology, pathophysiology, and literature review.

PubMed

Kumar, V Anil; Augustine, Deepthi; Panikar, Dilip; Nandakumar, Aswathy; Dinesh, Kavitha R; Karim, Shamsul; Philip, Rosamma

2014-10-01

Infections caused by Nocardia farcinica are potentially lethal because of the organism's tendency to disseminate and resist antibiotics. Central nervous system involvement has been documented in 30% of infections caused N. farcinica. Case report and review of the literature. A case of primary brain abscess caused by N. farcinica, identified by 16SrRNA sequencing, is presented, and 39 cases reported previously in the literature are reviewed. Our patient underwent a neuronavigation-guided right frontal craniotomy and was treated with trimethoprim/sulfamethoxazole and amoxicillin-clavulanic acid for 12 mo. He showed marginal improvement in his prior left hemiparesis at the last review 14 months later. Cases of N. farcinica infections are being reported increasingly because of recent changes in taxonomy and diagnostic methodology. This change in epidemiology has implications for therapy because of the organism's pathogenicity and natural resistance to multiple antimicrobial agents, including third-generation cephalosporins. Any delay in starting appropriate antibiotic therapy can have adverse consequences.

Glioma Surgery: Technological Advances to Achieve a Maximal Safe Resection.

PubMed

Altieri, Roberto; Zenga, Francesco; Fontanella, Marco Maria; Cofano, Fabio; Agnoletti, Alessandro; Spena, Giannantonio; Crobeddu, Emanuela; Fornaro, Riccardo; Ducati, Alessandro; Garbossa, Diego

2015-11-01

Glioblastoma multiforme (GBM) is the most frequent primary central nervous system (CNS) tumor. Despite the best treatment and advances in therapy, prognosis remains poor. One of the mainstays of therapy in GBM is surgical excision. Several studies have confirmed that the extent of resection (EOR) positively influences overall survival (OS) in patients with high-grade gliomas (HGGs). A literature search was performed using PubMed to assess the useful neurosurgical tools to achieve the best neurosurgical performance. In order to achieve the major extent of resection, preserving neurological function, many tools are now available, especially neuronavigation, intraoperative fluorescence, intraoperative ultrasound, and neuromonitoring. In addition to the maximal excision of tumor, the neurosurgeon can use photodynamic therapy (PTD) and local drug delivery (LDD) to improve the local control and bridge conventional radio and chemotherapy. EOR improves OS in patients with HGGs. There are technological possibilities for achieving a complete resection preserving neurological function, and it is not acceptable to perform only biopsy of these lesions.

Transcranial Magnetic Stimulation: An Automated Procedure to Obtain Coil-specific Models for Field Calculations.

PubMed

Madsen, Kristoffer H; Ewald, Lars; Siebner, Hartwig R; Thielscher, Axel

2015-01-01

Field calculations for transcranial magnetic stimulation (TMS) are increasingly implemented online in neuronavigation systems and in more realistic offline approaches based on finite-element methods. They are often based on simplified and/or non-validated models of the magnetic vector potential of the TMS coils. To develop an approach to reconstruct the magnetic vector potential based on automated measurements. We implemented a setup that simultaneously measures the three components of the magnetic field with high spatial resolution. This is complemented by a novel approach to determine the magnetic vector potential via volume integration of the measured field. The integration approach reproduces the vector potential with very good accuracy. The vector potential distribution of a standard figure-of-eight shaped coil determined with our setup corresponds well with that calculated using a model reconstructed from x-ray images. The setup can supply validated models for existing and newly appearing TMS coils. Copyright © 2015 Elsevier Inc. All rights reserved.

Intraoperative magnetic resonance imaging to update interactive navigation in neurosurgery: method and preliminary experience.

PubMed

Wirtz, C R; Bonsanto, M M; Knauth, M; Tronnier, V M; Albert, F K; Staubert, A; Kunze, S

1997-01-01

We report on the first successful intraoperative update of interactive image guidance based on an intraoperatively acquired magnetic resonance imaging (MRI) date set. To date, intraoperative imaging methods such as ultrasound, computerized tomography (CT), or MRI have not been successfully used to update interactive navigation. We developed a method of imaging patients intraoperatively with the surgical field exposed in an MRI scanner (Magnetom Open; Siemens Corp., Erlangen, Germany). In 12 patients, intraoperatively acquired 3D data sets were used for successful recalibration of neuronavigation, accounting for any anatomical changes caused by surgical manipulations. The MKM Microscope (Zeiss Corp., Oberkochen, Germany) was used as navigational system. With implantable fiducial markers, an accuracy of 0.84 +/- 0.4 mm for intraoperative reregistration was achieved. Residual tumor detected on MRI was consequently resected using navigation with the intraoperative data. No adverse effects were observed from intraoperative imaging or the use of navigation with intraoperative images, demonstrating the feasibility of recalibrating navigation with intraoperative MRI.

Framework for 2D-3D image fusion of infrared thermography with preoperative MRI.

PubMed

Hoffmann, Nico; Weidner, Florian; Urban, Peter; Meyer, Tobias; Schnabel, Christian; Radev, Yordan; Schackert, Gabriele; Petersohn, Uwe; Koch, Edmund; Gumhold, Stefan; Steiner, Gerald; Kirsch, Matthias

2017-11-27

Multimodal medical image fusion combines information of one or more images in order to improve the diagnostic value. While previous applications mainly focus on merging images from computed tomography, magnetic resonance imaging (MRI), ultrasonic and single-photon emission computed tomography, we propose a novel approach for the registration and fusion of preoperative 3D MRI with intraoperative 2D infrared thermography. Image-guided neurosurgeries are based on neuronavigation systems, which further allow us track the position and orientation of arbitrary cameras. Hereby, we are able to relate the 2D coordinate system of the infrared camera with the 3D MRI coordinate system. The registered image data are now combined by calibration-based image fusion in order to map our intraoperative 2D thermographic images onto the respective brain surface recovered from preoperative MRI. In extensive accuracy measurements, we found that the proposed framework achieves a mean accuracy of 2.46 mm.

Indocyanine Green Fluorescence Endoscopy at Endonasal Transsphenoidal Surgery for an Intracavernous Sinus Dermoid Cyst: Case Report

PubMed Central

HIDE, Takuichiro; YANO, Shigetoshi; KURATSU, Jun-ichi

2014-01-01

The complete resection of intracavernous sinus dermoid cysts is very difficult due to tumor tissue adherence to important anatomical structures such as the internal carotid artery (ICA), cavernous sinus, and cranial nerves. As residual dermoid cyst tissue sometimes induces symptoms and repeat surgery may be required after cyst recurrence, minimal invasiveness is an important consideration when selecting the surgical approach to the lesion. We addressed a recurrent intracavernous sinus dermoid cyst by the endoscopic endonasal transsphenoidal approach assisted by neuronavigation and indocyanine green (ICG) endoscopy to confirm the ICA and patency of the cavernous sinus. The ICG endoscope detected the fluorescence signal from the ICA and cavernous sinus; its intensity changed with the passage of time. The ICG endoscope was very useful for real-time imaging, and its high spatial resolution facilitated the detection of the ICA and the patent cavernous sinus. We found it to be of great value for successful endonasal transsphenoidal surgery. PMID:25446381

Occipital neuralgia secondary to unilateral atlantoaxial osteoarthritis: Case report and review of the literature

PubMed Central

Guha, Daipayan; Mohanty, Chandan; Tator, Charles H.; Shamji, Mohammed F.

2015-01-01

Background: Atlantoaxial osteoarthritis (AAOA), either in isolation or in the context of generalized peripheral or spinal arthritis, presents most commonly with neck pain and limitation of cervical rotational range of motion. Occipital neuralgia (ON) is only rarely attributed to AAOA, as fewer than 30 cases are described in the literature. Case Description: A 64-year-old female presented with progressive incapacitating cervicalgia and occipital headaches, refractory to medications, and local anesthetic blocks. Computed tomography and magnetic resonance imaging studies documented advanced unilateral atlantoaxial arthrosis with osteophytic compression that dorsally displaced the associated C2 nerve root. Surgical decompression and atlantoaxial fusion achieved rapid and complete relief of neuralgia. Ultimately, postoperative spinal imaging revealed osseous union. Conclusions: Atlantoaxial arthrosis must be considered in the differential diagnosis of ON. Surgical treatment is effective for managing refractory cases. Intraoperative neuronavigation is also a useful adjunct to guide instrumentation and the intraoperative extent of bony decompression. PMID:26759731

Vertebrobasilar junction giant aneurysm: Lessons learned from a neurosurgical audit and anatomical investigation.

PubMed

Graziano, Francesca; Ganau, Mario; Russo, Vittorio Maria; Iacopino, Domenico G; Ulm, Arthur John

2015-01-01

The treatment of vascular lesions of the vertebrobasilar junction (VBJ) remains a challenging task in the neurosurgical practice and the gold standard therapy is still under debate. In this article, the authors report a detailed postmortem study of a VBJ giant aneurysm (GA) previously endovascularly treated. Although the decision-making process for the vast majority of neurosurgical treatment can nowadays be accurately carried out during the preoperative planning (i.e., with the aid of neuroimaging fusion protocols, neuronavigation platforms, etc.) meant to maximize the anatomical understanding of the lesions and minimize possible intraprocedural challenges, this postmortem study represents the ultimate essence of neurosurgical audit as the laboratory investigations allowed to reevaluate the clinical history of VBJ GA, and reassess the multiple strategies available for its treatment with a straightforward anatomical perspective. Specifically, the lessons learned through this clinical and laboratory work uphold a great educational value regarding the complex management of those lesions, including the possible role of combined skull base surgical approaches.

[Brain metastasis from breast cancer: who?, when? and special considerations about the role of technology in neurosurgery].

PubMed

Dutertre, Guillaume; Pouit, Bruno

2011-04-01

Questions about both the place and the role of surgery on brain metastasis from breast cancer are arising more and more frequently in practice due to the increase of brain metastasis in patients suffering from a form of cancer recognized as one of the most recurrent cancers in adults but also one of the most sensitive to general treatments of the systemic disease. With improvements in anaesthesia, in surgical instruments, and in global care, neurosurgery has taken advantage of new techniques such as pre- and even per-operative imagery and also neuronavigation. These techniques enable radical and effective surgical intervention with a high level of safety for the patient, making neurosurgery perfectly competitive with other therapeutic modalities, particularly on functional grounds. As for symptomatic treatments or other anti-metastasis treatments, most situations allow a reflection on the global therapeutic strategy which can be adapted to individual cases depending on the patient's general prognosis. In developing this global therapeutic strategy, surgical treatment is still as relevant as ever.

Orbit-associated tumors: navigation and control of resection using intraoperative computed tomography.

PubMed

Terpolilli, Nicole A; Rachinger, Walter; Kunz, Mathias; Thon, Niklas; Flatz, Wilhelm H; Tonn, Jörg-Christian; Schichor, Christian

2016-05-01

OBJECT Treatment of skull base lesions is complex and usually requires a multidisciplinary approach. In meningioma, which is the most common tumor entity in this region, resection is considered to be the most important therapeutic step to avoid tumor recurrence. However, resection of skull base lesions with orbital or optic nerve involvement poses a challenge due to their anatomical structure and their proximity to eloquent areas. Therefore the main goal of surgery should be to achieve the maximum extent of resection while preserving neurological function. In the postoperative course, medical and radiotherapeutic strategies may then be successfully used to treat possible tumor residues. Methods to safely improve the extent of resection in skull base lesions therefore are desirable. The current study reports the authors' experience with the use of intraoperative CT (iCT) combined with neuronavigation with regard to feasibility and possible benefits of the method. METHODS Those patients with tumorous lesions in relationship to the orbit, sphenoid wing, or cavernous sinus who were surgically treated between October 2008 and December 2013 using iCT-based neuronavigation and in whom an intraoperative scan was obtained for control of resection were included. In all cases a second iCT scan was performed under sterile conditions after completion of navigation-guided microsurgical tumor resection. The surgical strategy was adapted accordingly; if necessary, resection was continued. RESULTS Twenty-three patients (19 with WHO Grade I meningioma and 4 with other lesions) were included. The most common clinical symptoms were loss of visual acuity and exophthalmus. Intraoperative control of resection by iCT was successfully obtained in all cases. Intraoperative imaging changed the surgical approach in more than half (52.2%) of these patients, either because iCT demonstrated unexpected residual tumor masses or because the second scan revealed additional tumor tissue that was not

Surgical Management of Giant Intracranial Meningioma: Operative Nuances, Challenges, and Outcome.

PubMed

Narayan, Vinayak; Bir, Shyamal C; Mohammed, Nasser; Savardekar, Amey R; Patra, Devi Prasad; Nanda, Anil

2018-02-01

The giant intracranial meningioma (GIM) constitutes a different spectrum of brain tumors that invade the vital neurovascular structures, which makes the primary mode of treatment, surgery, a technically challenging one. The surgery for GIM is unique because of the large size of the tumor, prominent vascularity, entangling and limited visualization of various neurovascular structures, and severe cerebral edema. This study reports the authors surgical experience of 80 GIM cases, the operative challenges and surgical outcome. A retrospective analysis of 80 patients with histologically proven meningioma (≥5 cm) who underwent surgical treatment at Louisiana State University Health Sciences Center (Shreveport, Louisiana, USA) over a 20-year period (1995-2015) is presented. The clinical and radiologic data were collected from the hospital database. The tumors were categorized into histologic groups according to World Health Organization (WHO) classification. The relevant statistical analysis of the study was conducted using SPSS software, version 22.0. The study included 27 male patients (33.8%) and 53 female patients (66.3%). The mean age of the cohort was 56 years (56.3±16.1). The mean size of the tumor was 56.4 ±4 mm with a range from 50 mm to 84 mm. Skull base was the most common location of GIM (57 patients, 71.3%). Simpson grade 1 excision was achieved in 9 patients (11.3%), whereas grade 2 excision was achieved in 57 patients (71.3%); 80% of the tumors belonged to WHO grade 1. The operative mortality was seen in 4 patients (5%). Regression analysis showed that age, sex, location of the tumor, neuronavigation, Simpson grade of excision, and histology of tumor were the factors that significantly affected the recurrence-free survival (RFS). The surgery for GIM is unique in different ways. As surgery for GIM is formidable, radiologic characteristics can be useful adjuncts for planning an effective and safe surgical strategy. The factors such as young age, male sex

Multimodal Navigation in Endoscopic Transsphenoidal Resection of Pituitary Tumors using Image-based Vascular and Cranial Nerve Segmentation: A Prospective Validation Study

PubMed Central

Dolati, Parviz; Eichberg, Daniel; Golby, Alexandra; Zamani, Amir; Laws, Edward

2016-01-01

Introduction Transsphenoidal surgery (TSS) is a well-known approach for the treatment of pituitary tumors. However, lateral misdirection and vascular damage, intraoperative CSF leakage, and optic nerve and vascular injuries are all well-known complications, and the risk of adverse events is more likely in less experienced hands. This prospective study was conducted to validate the accuracy of image-based segmentation in localization of neurovascular structures during TSS. Methods Twenty-five patients with pituitary tumors underwent preoperative 3TMRI, which included thin-sectioned 3D space T2, 3D Time of Flight and MPRAGE sequences. Images were reviewed by an expert independent neuroradiologist. Imaging sequences were loaded in BrainLab iPlanNet (16/25 cases) or Stryker (9/25 cases) image guidance platforms for segmentation and pre-operative planning. After patient registration into the neuronavigation system and subsequent surgical exposure, each segmented neural or vascular element was validated by manual placement of the navigation probe on or as close as possible to the target. The audible pulsations of the bilateral ICA were confirmed using a micro-Doppler probe. Results Pre-operative segmentation of the ICA and cavernous sinus matched with the intra-operative endoscopic and micro-Doppler findings in all cases (Dice Similarity Coefficient =1). This information reassured the surgeons with regard to the lateral extent of bone removal at the sellar floor and the limits of lateral exploration. Excellent correspondence between image-based segmentation and the endoscopic view was also evident at the surface of the tumor and at the tumor-normal gland interfaces. This assisted in preventing unnecessary removal of the normal pituitary gland. Image-guidance assisted the surgeons in localizing the optic nerve and chiasm in 64% of the cases and the diaphragma sella in 52% of cases, which helped to determine the limits of upward exploration and to decrease the risk of CSF

Direct access to the middle meningeal artery for embolization of complex dural arteriovenous fistula: a hybrid treatment approach

PubMed Central

Lin, Ning; Brouillard, Adam M; Mokin, Maxim; Natarajan, Sabareesh K; Snyder, Kenneth V; Levy, Elad I; Siddiqui, Adnan H

2014-01-01

Endovascular embolization has become increasingly favored over microsurgical resection for treatment of complex dural arteriovenous fistulas (DAVFs). However, endovascular treatment can be restricted by tortuous transarterial access and a transvenous approach is not always feasible. We present a Borden III DAVF treated by direct access to the middle meningeal artery (MMA) and Onyx embolization performed in a hybrid operating room–angiography suite. A middle-aged patient with pulsatile headaches was found to have left transverse sinus occlusion and DAVF with retrograde cortical venous drainage fed by multiple external carotid artery (ECA) feeders. Endovascular attempts via conventional transvenous and transarterial routes were unsuccessful, and the major MMA feeder was accessed directly after temporal craniotomy was performed under neuronavigation. Onyx embolization was performed; complete occlusion of the fistula was achieved. Three-month follow-up angiography showed no residual filling; the patient remains complication-free. A combined surgical–endovascular technique in a hybrid operating room–angiography suite can be an effective treatment for DAVFs complicated by inaccessible arterial and transvenous approaches. PMID:24903968

Design optimization of the sensor spatial arrangement in a direct magnetic field-based localization system for medical applications.

PubMed

Marechal, Luc; Shaohui Foong; Zhenglong Sun; Wood, Kristin L

2015-08-01

Motivated by the need for developing a neuronavigation system to improve efficacy of intracranial surgical procedures, a localization system using passive magnetic fields for real-time monitoring of the insertion process of an external ventricular drain (EVD) catheter is conceived and developed. This system operates on the principle of measuring the static magnetic field of a magnetic marker using an array of magnetic sensors. An artificial neural network (ANN) is directly used for solving the inverse problem of magnetic dipole localization for improved efficiency and precision. As the accuracy of localization system is highly dependent on the sensor spatial location, an optimization framework, based on understanding and classification of experimental sensor characteristics as well as prior knowledge of the general trajectory of the localization pathway, for design of such sensing assemblies is described and investigated in this paper. Both optimized and non-optimized sensor configurations were experimentally evaluated and results show superior performance from the optimized configuration. While the approach presented here utilizes ventriculostomy as an illustrative platform, it can be extended to other medical applications that require localization inside the body.

Awake craniotomy using electromagnetic navigation technology without rigid pin fixation.

PubMed

Morsy, Ahmed A; Ng, Wai Hoe

2015-11-01

We report our institutional experience using an electromagnetic navigation system, without rigid head fixation, for awake craniotomy patients. The StealthStation® S7 AxiEM™ navigation system (Medtronic, Inc.) was used for this technique. Detailed preoperative clinical and neuropsychological evaluations, patient education and contrast-enhanced MRI (thickness 1.5mm) were performed for each patient. The AxiEM Mobile Emitter was typically placed in a holder, which was mounted to the operating room table, and a non-invasive patient tracker was used as the patient reference device. A monitored conscious sedation technique was used in all awake craniotomy patients, and the AxiEM Navigation Pointer was used for navigation during the procedure. This offers the same accuracy as optical navigation, but without head pin fixation or interference with intraoperative neurophysiological techniques and surgical instruments. The application of the electromagnetic neuronavigation technology without rigid head fixation during an awake craniotomy is accurate, and offers superior patient comfort. It is recommended as an effective adjunctive technique for the conduct of awake surgery. Copyright © 2015 Elsevier Ltd. All rights reserved.

Detection of histological anaplasia in gliomas with oligodendroglial components using positron emission tomography with (18)F-FDG and (11)C-methionine: report of two cases.

PubMed

Yamaguchi, Shigeru; Kobayashi, Hiroyuki; Hirata, Kenji; Shiga, Tohru; Tanaka, Shinya; Murata, Junichi; Terasaka, Shunsuke

2011-01-01

Gliomas are regionally heterogeneous tumors. Positron emission tomography (PET) with (18)F-fluorodeoxyglucose (FDG) and (11)C-methionine (MET) evaluates the heterogeneity of histological malignancy within the tumor. We present two patients with oligodendrocytic tumors that showed discrepancies in the highest uptake areas with these two tracers. PET studies with MET and FDG were performed on the same day, 2 weeks before surgery. In both cases, biopsy specimens were separately obtained from the highest MET and FDG uptake areas guided by intraoperative neuronavigation. Histological examinations demonstrated that the specimens from the highest MET uptake area revealed low-grade oligoastrocytoma or oligodendroglioma, whereas histological anaplasias were contained in the specimens from the highest FDG uptake area. With gliomas with oligodendroglial components, the MET uptake ratio does not always correspond to histological anaplasia, which can be detected only by FDG PET. Sole application of MET PET for preoperative evaluation may lead to misunderstanding of histological heterogeneity in gliomas, especially those with oligodendroglial components. FDG and MET tracers play complementary roles in preoperative evaluation of gliomas.

Repetitive Transcranial Magnetic Stimulation (rTMS) Treatment in Enduring Anorexia Nervosa: A Case Series.

PubMed

McClelland, Jessica; Kekic, Maria; Campbell, Iain C; Schmidt, Ulrike

2016-03-01

This case series examined the therapeutic potential of repetitive transcranial magnetic stimulation in five women with enduring anorexia nervosa. Participants received ~20 sessions of neuronavigated high-frequency repetitive transcranial magnetic stimulation to the left dorsolateral prefrontal cortex. Body mass index, eating disorder (ED) symptoms and mood were assessed pre-treatment and post-treatment, at 6-month and 12-month follow-up (FU). Qualitative feedback regarding the intervention was obtained from participants and carers. From pre-treatment to post-treatment, ED and affective symptoms improved significantly, and body mass index remained stable. Further improvements in ED symptoms/mood were seen at 6-month FU with 3/5 and 2/5 participants deemed 'recovered' on the Eating Disorders Examination Questionnaire and Depression, Anxiety and Stress Scale, respectively. However, most participants had lost some weight, and therapeutic effects on psychopathology had waned by 12-month FU. Qualitative feedback regarding the intervention was encouraging. Repetitive transcranial magnetic stimulation was well tolerated, and preliminary evidence is provided for its therapeutic potential in anorexia nervosa. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.

Repetitive Transcranial Magnetic Stimulation to Supplementary Motor Area in Refractory Obsessive-Compulsive Disorder Treatment: a Sham-Controlled Trial.

PubMed

Pelissolo, Antoine; Harika-Germaneau, Ghina; Rachid, Fady; Gaudeau-Bosma, Christian; Tanguy, Marie-Laure; BenAdhira, Rene; Bouaziz, Noomane; Popa, Traian; Wassouf, Issa; Saba, Ghassen; Januel, Dominique; Jaafari, Nematollah

2016-08-01

Repetitive transcranial magnetic stimulation has been explored in patients with obsessive-compulsive disorder, but with negative or conflicting results. This randomized double-blind study was designed to assess the efficacy of 1-Hz repetitive transcranial magnetic stimulation over the presupplementary area. Forty medication-resistant patients were assigned to 4 weeks of either active or sham repetitive transcranial magnetic stimulation targeting the presupplementary area with the help of a neuronavigation system. According to the Yale-Brown obsessive-compulsive scale, the baseline-week 4 evolution showed no significant differences between groups. Responder rates at week 4 were not different between groups (repetitive transcranial magnetic stimulation 10.5% vs sham 20%; P=.63). Low-frequency repetitive transcranial magnetic stimulation applied to the presupplementary area seems ineffective for the treatment of obsessive-compulsive disorder patients, at least in severe and drug-refractory cases such as those included in this study. Further research is required to determine profiles of responder patients and appropriate repetitive transcranial magnetic stimulation parameters for obsessive-compulsive disorder. © The Author 2016. Published by Oxford University Press on behalf of CINP.

Intraoperative navigation-guided resection of anomalous transverse processes in patients with Bertolotti's syndrome

PubMed Central

Babu, Harish; Lagman, Carlito; Kim, Terrence T.; Grode, Marshall; Johnson, J. Patrick; Drazin, Doniel

2017-01-01

Background: Bertolotti's syndrome is characterized by enlargement of the transverse process at the most caudal lumbar vertebra with a pseudoarticulation between the transverse process and sacral ala. Here, we describe the use of intraoperative three-dimensional image-guided navigation in the resection of anomalous transverse processes in two patients with Bertolotti's syndrome. Case Descriptions: Two patients diagnosed with Bertolotti's syndrome who had undergone the above-mentioned procedure were identified. The patients were 17- and 38-years-old, and presented with severe, chronic low back pain that was resistant to conservative treatment. Imaging revealed lumbosacral transitional vertebrae at the level of L5-S1, which was consistent with Bertolotti's syndrome. Injections of the pseudoarticulations resulted in only temporary symptomatic relief. Thus, the patients subsequently underwent O-arm neuronavigational resection of the bony defects. Both patients experienced immediate pain resolution (documented on the postoperative notes) and remained asymptomatic 1 year later. Conclusion: Intraoperative three-dimensional imaging and navigation guidance facilitated the resection of anomalous transverse processes in two patients with Bertolotti's syndrome. Excellent outcomes were achieved in both patients. PMID:29026672

Intraoperative navigation-guided resection of anomalous transverse processes in patients with Bertolotti's syndrome.

PubMed

Babu, Harish; Lagman, Carlito; Kim, Terrence T; Grode, Marshall; Johnson, J Patrick; Drazin, Doniel

2017-01-01

Bertolotti's syndrome is characterized by enlargement of the transverse process at the most caudal lumbar vertebra with a pseudoarticulation between the transverse process and sacral ala. Here, we describe the use of intraoperative three-dimensional image-guided navigation in the resection of anomalous transverse processes in two patients with Bertolotti's syndrome. Two patients diagnosed with Bertolotti's syndrome who had undergone the above-mentioned procedure were identified. The patients were 17- and 38-years-old, and presented with severe, chronic low back pain that was resistant to conservative treatment. Imaging revealed lumbosacral transitional vertebrae at the level of L5-S1, which was consistent with Bertolotti's syndrome. Injections of the pseudoarticulations resulted in only temporary symptomatic relief. Thus, the patients subsequently underwent O-arm neuronavigational resection of the bony defects. Both patients experienced immediate pain resolution (documented on the postoperative notes) and remained asymptomatic 1 year later. Intraoperative three-dimensional imaging and navigation guidance facilitated the resection of anomalous transverse processes in two patients with Bertolotti's syndrome. Excellent outcomes were achieved in both patients.

Correlation of the CT Compatible Stereotaxic Craniotomy with MRI Scans of the Patients for Removing Cranial Lesions Located Eloquent Areas and Deep Sites of Brain.

PubMed

Gulsen, Salih

2015-03-15

The first goal in neurosurgery is to protect neural function as long as it is possible. Moreover, while protecting the neural function, a neurosurgeon should extract the maximum amount of tumoral tissue from the tumour region of the brain. So neurosurgery and technological advancement go hand in hand to realize this goal. Using of CT compatible stereotaxy for removing a cranial tumour is to be commended as a cornerstone of these technological advancements. Following CT compatible stereotaxic system applications in neurosurgery, different techniques have taken place in neurosurgical practice. These techniques are magnetic resonance imaging (MRI), MRI compatible stereotaxis, frameless stereotaxy, volumetric stereotaxy, functional MRI, diffusion tensor (DT) imaging techniques (tractography of the white matter), intraoperative MRI and neuronavigation systems. However, to use all of this equipment having these technologies would be impossible because of economic reasons. However, when we correlated this technique with MRI scans of the patients with CT compatible stereotaxy scans, it is possible to provide gross total resection and protect and improve patients' neural functions.

Anesthesia for minimally invasive neurosurgery.

PubMed

Prabhakar, Hemanshu; Mahajan, Charu; Kapoor, Indu

2017-10-01

With an ultimate aim of improving patients overall outcome and satisfaction, minimally invasive surgical approach is becoming more of a norm. The related anesthetic evidence has not expanded at the same rate as surgical and technological advancement. This article reviews the recent evidence on anesthesia and perioperative concerns for patients undergoing minimally invasive neurosurgery. Minimally invasive cranial and spinal surgeries have been made possible only by vast technological development. Points of surgical interest can be precisely located with the help of stereotaxy and neuronavigation and special endoscopes which decrease the tissue trauma. The principles of neuroanethesia remain the same, but few concerns are specific for each technique. Dexmedetomidine has a favorable profile for procedures carried out under sedation technique. As the new surgical techniques are coming up, lesser known anesthetic concerns may also come into light. Over the last year, little new information has been added to existing literature regarding anesthesia for minimally invasive neurosurgeries. Neuroanesthesia goals remain the same and less invasive surgical techniques do not translate into safe anesthesia. Specific concerns for each procedure should be taken into consideration.

The Barrow Innovation Center Case Series: A novel 3D-printed retractor for use with electromagnetic neuronavigation systems.

PubMed

Bohl, Michael A; Xu, David S; Cavallo, Claudio; Paisan, Gabriella M; Smith, Kris A; Nakaji, Peter

2018-06-01

The Barrow Innovation Center consists of an educational program that promotes interdisciplinary collaboration among neurosurgery, legal, and engineering professionals to foster the development of new medical devices. This report describes a common issue faced during the placement of ventricular shunts for the treatment of hydrocephalus, and the solution to this problem that was developed through the Barrow Innovation Center. Neurosurgery residents involved in the Barrow Innovation Center presented the problem of ferromagnetic retractors interfering with pinless image-guidance systems at a monthly meeting. Potential solutions were openly discussed by an interdisciplinary committee of neurosurgeons, patent lawyers, and biomedical engineers. The committee decided to pursue development of a novel self-retaining retractor made of non-ferromagnetic material as a solution to the problem. Each retractor design was tested in the cadaver laboratory for size and functionality. A final design was chosen and used in a surgical case requiring ventriculoperitoneal shunt placement. The new retractor successfully retracted the scalp without interfering with the electromagnetic image-guidance system. Through the interdisciplinary Barrow Innovation Center program, a newly designed, 3-dimensional-printed skin and soft tissue retractor was created, along with an innovative universal shunt retainer. Through this integrated program dedicated to surgical innovation (i.e., the Barrow Innovation Center), the process of developing and implementing new technology at our institution has been streamlined, creating a culture of innovation within the neurosurgery training program. Copyright © 2018 Elsevier Inc. All rights reserved.

Intraoperative computed tomography with integrated navigation system in spinal stabilizations.

PubMed

Zausinger, Stefan; Scheder, Ben; Uhl, Eberhard; Heigl, Thomas; Morhard, Dominik; Tonn, Joerg-Christian

2009-12-15

STUDY DESIGN.: A prospective interventional case-series study plus a retrospective analysis of historical patients for comparison of data. OBJECTIVE.: To evaluate workflow, feasibility, and clinical outcome of navigated stabilization procedures with data acquisition by intraoperative computed tomography. SUMMARY OF BACKGROUND DATA.: Routine fluoroscopy to assess pedicle screw placement is not consistently reliable. Our hypothesis was that image-guided spinal navigation using an intraoperative CT-scanner can improve the safety and precision of spinal stabilization surgery. METHODS.: CT data of 94 patients (thoracolumbar [n = 66], C1/2 [n = 12], cervicothoracic instability [n = 16]) were acquired after positioning the patient in the final surgical position. A sliding gantry 40-slice CT was used for image acquisition. Data were imported to a frameless infrared-based neuronavigation workstation. Intraoperative CT was obtained to assess the accuracy of instrumentation and, if necessary, the extent of decompression. All patients were clinically evaluated by Odom-criteria after surgery and after 3 months. RESULTS.: Computed accuracy of the navigation system reached <2 mm (0.95 +/- 0.3 mm) in all cases. Additional time necessary for the preoperative image acquisition including data transfer was 14 +/- 5 minutes. The duration of interrupting the surgical process for iCT until resumption of surgery was 9 +/- 2.5 minutes. Control-iCT revealed incorrect screw position >/=2 mm without persistent neurologic or vascular damage in 20/414 screws (4.8%) leading to immediate correction of 10 screws (2.4%). Control-iCT changed the course of surgery in 8 cases (8.5% of all patients). The overall revision rate was 8.5% (4 wound revisions, 2 CSF fistulas, and 2 epidural hematomas). There was no reoperation due to implant malposition. According to Odom-criteria all patients experienced a clinical improvement. A retrospective analysis of 182 patients with navigated thoracolumbar

Hemispheric differences in the voluntary control of spatial attention: direct evidence for a right-hemispheric dominance within frontal cortex.

PubMed

Duecker, Felix; Formisano, Elia; Sack, Alexander T

2013-08-01

Lesion studies in neglect patients have inspired two competing models of spatial attention control, namely, Heilman's "hemispatial" theory and Kinsbourne's "opponent processor" model. Both assume a functional asymmetry between the two hemispheres but propose very different mechanisms. Neuroimaging studies have identified a bilateral dorsal frontoparietal network underlying voluntary shifts of spatial attention. However, lateralization of attentional processes within this network has not been consistently reported. In the current study, we aimed to provide direct evidence concerning the functional asymmetry of the right and left FEF during voluntary shifts of spatial attention. To this end, we applied fMRI-guided neuronavigation to disrupt individual FEF activation foci with a longer-lasting inhibitory patterned TMS protocol followed by a spatial cueing task. Our results indicate that right FEF stimulation impaired the ability of shifting spatial attention toward both hemifields, whereas the effects of left FEF stimulation were limited to the contralateral hemifield. These results provide strong direct evidence for right-hemispheric dominance in spatial attention within frontal cortex supporting Heilman's "hemispatial" theory. This complements previous TMS studies that generally conform to Kinsbourne's "opponent processor" model after disruption of parietal cortex, and we therefore propose that both theories are not mutually exclusive.

Transzygomatic approach with intraoperative neuromonitoring for resection of middle cranial fossa tumors.

PubMed

Son, Byung Chul; Lee, Sang Won; Kim, Sup; Hong, Jae Taek; Sung, Jae Hoon; Yang, Seung-Ho

2012-02-01

The authors reviewed the surgical experience and operative technique in a series of 11 patients with middle fossa tumors who underwent surgery using the transzygomatic approach and intraoperative neuromonitoring (IOM) at a single institution. This approach was applied to trigeminal schwannomas (n = 3), cavernous angiomas (n = 3), sphenoid wing meningiomas (n = 3), a petroclival meningioma (n = 1), and a hemangiopericytoma (n = 1). An osteotomy of the zygoma, a low-positioned frontotemporal craniotomy, removal of the remaining squamous temporal bone, and extradural drilling of the sphenoid wing made a flat trajectory to the skull base. Total resection was achieved in 9 of 11 patients. Significant motor pathway damage can be avoided using a change in motor-evoked potentials as an early warning sign. Four patients experienced cranial nerve palsies postoperatively, even though free-running electromyography of cranial nerves showed normal responses during the surgical procedure. A simple transzygomatic approach provides a wide surgical corridor for accessing the cavernous sinus, petrous apex, and subtemporal regions. Knowledge of the middle fossa structures is essential for anatomic orientation and avoiding injuries to neurovascular structures, although a neuronavigation system and IOM helps orient neurosurgeons.

Intraoperative definition of bottom-of-sulcus dysplasia using intraoperative ultrasound and single depth electrode recording - A technical note.

PubMed

Miller, Dorothea; Carney, Patrick; Archer, John S; Fitt, Gregory J; Jackson, Graeme D; Bulluss, Kristian J

2018-02-01

Bottom of sulcus dysplasias (BOSDs) are localized focal cortical dysplasias (FCDs) centred on the bottom of a sulcus that can be highly epileptogenic, but difficult to delineate intraoperatively. We report on a patient with refractory epilepsy due to a BOSD, successfully resected with the aid of a multimodal surgical approach using neuronavigation based on MRI and PET, intraoperative ultrasound (iUS) and electrocorticography (ECoG) using depth electrodes. The lesion could be visualized on iUS showing an increase in echogenicity at the grey-white matter junction. IUS demonstrated the position of the depth electrode in relation to the lesion. Depth electrode recording showed almost continuous spiking. Thus, intraoperative imaging and electrophysiology helped confirm the exact location of the lesion. Post-resection ultrasound demonstrated the extent of the resection and depth electrode recording did not show any epileptiform activity. Thus, both techniques helped assess completeness of resection. The patient has been seizure free since surgery. Using a multimodal approach including iUS and ECoG is a helpful adjunct in surgery for BOSD and may improve seizure outcome. Copyright © 2017 Elsevier Ltd. All rights reserved.

Intermittent theta-burst transcranial magnetic stimulation for autism spectrum disorder: an open-label pilot study.

PubMed

Abujadi, Caio; Croarkin, Paul E; Bellini, Bianca B; Brentani, Helena; Marcolin, Marco A

2017-12-11

Theta-burst stimulation (TBS) modulates synaptic plasticity more efficiently than standard repetitive transcranial magnetic stimulation delivery and may be a promising modality for neuropsychiatric disorders such as autism spectrum disorder (ASD). At present there are few effective interventions for prefrontal cortex dysfunction in ASD. We report on an open-label, pilot study of intermittent TBS (iTBS) to target executive function deficits and restricted, repetitive behaviors in male children and adolescents with ASD. Ten right-handed, male participants, aged 9-17 years with ASD were enrolled in an open-label trial of iTBS treatment. Fifteen sessions of neuronavigated iTBS at 100% motor threshold targeting the right dorsolateral prefrontal cortex were delivered over 3 weeks. Parent report scores on the Repetitive Behavior Scale Revised and the Yale-Brown Obsessive Compulsive Scale demonstrated improvements with iTBS treatment. Participants demonstrated improvements in perseverative errors on the Wisconsin Card Sorting Test and total time for the Stroop test. The iTBS treatments were well tolerated with no serious adverse effects. These preliminary results suggest that further controlled interventional studies of iTBS for ASD are warranted.

Image Guidance to Aid Pedicle Screw Fixation of a Lumbar Fracture-Dislocation Injury in a Toddler.

PubMed

Houten, John K; Nahkla, Jonathan; Ghandi, Shashank

2017-09-01

Pedicle screw fixation of the lumbar spine in children age <2 years is particularly challenging, as successful cannulation of the small pedicle dimensions requires a high level of precision and there are no implants specifically designed for the infant spine. Image-guided navigation is commonly used in adult spinal surgery and may be particularly helpful for the placement of spinal screws in areas where the bony anatomy is small and/or anatomically complex, as in the upper cervical area. A 19-month-old female presented with a fracture-dislocation injury of L1-2. Intraoperative imaging using the O-arm multidimensional imaging system was networked to a workstation, and neuronavigation was used to place pedicle instrumentation with 3.5-mm-diameter polyaxial screws designed for posterior cervical fixation. At a 48-month follow-up, the patient was neurologically intact, demonstrated normal physical development, and was engaging in normal physical activity for her age. Radiographs obtained approximately 4 years postsurgery showed no evidence of loss for fixation. Image-guided placement of pedicle screws may be a useful aid in achieving accurate and safe fixation in the small dimensions of the infant spine. Copyright © 2017 Elsevier Inc. All rights reserved.

Navigation-supported diagnosis of the substantia nigra by matching midbrain sonography and MRI

NASA Astrophysics Data System (ADS)

Salah, Zein; Weise, David; Preim, Bernhard; Classen, Joseph; Rose, Georg

2012-03-01

Transcranial sonography (TCS) is a well-established neuroimaging technique that allows for visualizing several brainstem structures, including the substantia nigra, and helps for the diagnosis and differential diagnosis of various movement disorders, especially in Parkinsonian syndromes. However, proximate brainstem anatomy can hardly be recognized due to the limited image quality of B-scans. In this paper, a visualization system for the diagnosis of the substantia nigra is presented, which utilizes neuronavigated TCS to reconstruct tomographical slices from registered MRI datasets and visualizes them simultaneously with corresponding TCS planes in realtime. To generate MRI tomographical slices, the tracking data of the calibrated ultrasound probe are passed to an optimized slicing algorithm, which computes cross sections at arbitrary positions and orientations from the registered MRI dataset. The extracted MRI cross sections are finally fused with the region of interest from the ultrasound image. The system allows for the computation and visualization of slices at a near real-time rate. Primary tests of the system show an added value to the pure sonographic imaging. The system also allows for reconstructing volumetric (3D) ultrasonic data of the region of interest, and thus contributes to enhancing the diagnostic yield of midbrain sonography.

White matter fiber tracking computation based on diffusion tensor imaging for clinical applications.

PubMed

Dellani, Paulo R; Glaser, Martin; Wille, Paulo R; Vucurevic, Goran; Stadie, Axel; Bauermann, Thomas; Tropine, Andrei; Perneczky, Axel; von Wangenheim, Aldo; Stoeter, Peter

2007-03-01

Fiber tracking allows the in vivo reconstruction of human brain white matter fiber trajectories based on magnetic resonance diffusion tensor imaging (MR-DTI), but its application in the clinical routine is still in its infancy. In this study, we present a new software for fiber tracking, developed on top of a general-purpose DICOM (digital imaging and communications in medicine) framework, which can be easily integrated into existing picture archiving and communication system (PACS) of radiological institutions. Images combining anatomical information and the localization of different fiber tract trajectories can be encoded and exported in DICOM and Analyze formats, which are valuable resources in the clinical applications of this method. Fiber tracking was implemented based on existing line propagation algorithms, but it includes a heuristic for fiber crossings in the case of disk-shaped diffusion tensors. We successfully performed fiber tracking on MR-DTI data sets from 26 patients with different types of brain lesions affecting the corticospinal tracts. In all cases, the trajectories of the central spinal tract (pyramidal tract) were reconstructed and could be applied at the planning phase of the surgery as well as in intraoperative neuronavigation.

Intraventricular and skull base neuroendoscopy in 2012: a global survey of usage patterns and the role of intraoperative neuronavigation.

PubMed

Esposito, Felice; Di Rocco, Federico; Zada, Gabriel; Cinalli, Giuseppe; Schroeder, Henry W S; Mallucci, Conor; Cavallo, Luigi M; Decq, Philippe; Chiaramonte, Carmela; Cappabianca, Paolo

2013-12-01

During the past decade, endoscopic intraventricular and skull base operations have become widely used for a variety of evolving indications. A global survey of practicing endoscopic neurosurgeons was performed to characterize patterns of usage regarding endoscopy equipment, instrumentation, and the indications for using image-guided surgery systems (IGSs). An online survey consisting of 8 questions was completed by 235 neurosurgeons with endoscopic surgical experience. Responses were entered into a database and subsequently analyzed. The median number of operations performed per year by intraventricular and skull base endoscopic surgeons was 27 and 25, respectively. Data regarding endoscopic equipment brand, diameter, and length are presented. The most commonly reported indications for IGSs during intraventricular endoscopic surgery were tumor biopsy/resection, intraventricular cyst fenestration, septostomy/pellucidotomy, endoscopic third ventriculostomy, and aqueductal stent placement. Intraventricular surgeons reported using IGSs for all cases in 16.6% and never in 24.4%. Overall, endoscopic skull base surgeons reported using IGSs for all cases in 23.9% and never in 18.9%. The most commonly reported indications for IGSs during endoscopic skull base operations were complex sinus/skull base anatomy, extended approaches, and reoperation. Many variations and permutations for performing intraventricular and skull base endoscopic surgery exist worldwide. Much can be learned by studying the patterns and indications for using various types of equipment and operative adjuncts such as IGSs. Copyright © 2013 Elsevier Inc. All rights reserved.

Screw Placement Accuracy for Minimally Invasive Transforaminal Lumbar Interbody Fusion Surgery: A Study on 3-D Neuronavigation-Guided Surgery

PubMed Central

Torres, Jorge; James, Andrew R.; Alimi, Marjan; Tsiouris, Apostolos John; Geannette, Christian; Härtl, Roger

2012-01-01

Purpose The aim of this study was to assess the impact of 3-D navigation for pedicle screw placement accuracy in minimally invasive transverse lumbar interbody fusion (MIS-TLIF). Methods A retrospective review of 52 patients who had MIS-TLIF assisted with 3D navigation is presented. Clinical outcomes were assessed with the Oswestry Disability Index (ODI), Visual Analog Scales (VAS), and MacNab scores. Radiographic outcomes were assessed using X-rays and thin-slice computed tomography. Result The mean age was 56.5 years, and 172 screws were implanted with 16 pedicle breaches (91.0% accuracy rate). Radiographic fusion rate at a mean follow-up of 15.6 months was 87.23%. No revision surgeries were required. The mean improvement in the VAS back pain, VAS leg pain, and ODI at 11.3 months follow-up was 4.3, 4.5, and 26.8 points, respectively. At last follow-up the mean postoperative disc height gain was 4.92 mm and the mean postoperative disc angle gain was 2.79 degrees. At L5–S1 level, there was a significant correlation between a greater disc space height gain and a lower VAS leg score. Conclusion Our data support that application of 3-D navigation in MIS-TLIF is associated with a high level of accuracy in the pedicle screw placement. PMID:24353961

Transcranial magnetic stimulation for the treatment of tinnitus: a new coil positioning method and first results.

PubMed

Langguth, Berthold; Zowe, Marc; Landgrebe, Michael; Sand, Philipp; Kleinjung, Tobias; Binder, Harald; Hajak, Göran; Eichhammer, Peter

2006-01-01

Auditory phantom perceptions are associated with hyperactivity of the central auditory system. Neuronavigation guided repetitive transcranial magnetic stimulation (rTMS) of the area of increased activity was demonstrated to reduce tinnitus perception. The study aimed at developing an easy applicable standard procedure for transcranial magnetic stimulation of the primary auditory cortex and to investigate this coil positioning strategy for the treatment of chronic tinnitus in clinical practice. The left gyrus of Heschl was targeted in 25 healthy subjects using a frameless stereotactical system. Based on individual scalp coordinates of the coil, a positioning strategy with reference to the 10--20-EEG system was developed. Using this coil positioning approach we started an open treatment trial. 28 patients with chronic tinnitus received 10 sessions of rTMS (intensity 110% of motor threshold, 1 Hz, 2000 Stimuli/day). Being within a range of about 20 mm diameter, the scalp coordinates for stimulating the primary auditory cortex allowed to determine a standard procedure for coil positioning. Clinical validation of this coil positioning method resulted in a significant improvement of tinnitus complaints (p<0.001). The newly developed coil positioning strategy may have the potential to offer a more easy-to-use stimulation approach for treating chronic tinnitus as compared with highly sophisticated, imaging guided treatment methods.

Initial experience of using high field strength intraoperative MRI for neurosurgical procedures.

PubMed

Raheja, Amol; Tandon, Vivek; Suri, Ashish; Sarat Chandra, P; Kale, Shashank S; Garg, Ajay; Pandey, Ravindra M; Kalaivani, Mani; Mahapatra, Ashok K; Sharma, Bhawani S

2015-08-01

We report our initial experience to optimize neurosurgical procedures using high field strength intraoperative magnetic resonance imaging (IOMRI) in 300 consecutive patients as high field strength IOMRI rapidly becomes the standard of care for neurosurgical procedures. Three sequential groups (groups A, B, C; n=100 each) were compared with respect to time management, complications and technical difficulties to assess improvement in these parameters with experience. We observed a reduction in the number of technical difficulties (p<0.001), time to induction (p<0.001) and total anesthesia time (p=0.007) in sequential groups. IOMRI was performed for neuronavigation guidance (n=252) and intraoperative validation of extent of resection (EOR; n=67). Performing IOMRI increased the EOR over and beyond the primary surgical attempt in 20.5% (29/141) and 18% (11/61) of patients undergoing glioma and pituitary surgery, respectively. Overall, EOR improved in 59.7% of patients undergoing IOMRI (40/67). Intraoperative tractography and real time navigation using re-uploaded IOMRI images (accounting for brain shift) helps in intraoperative planning to reduce complications. IOMRI is an asset to neurosurgeons, helping to augment the EOR, especially in glioma and pituitary surgery, with no significant increase in morbidity to the patient. Copyright © 2015 Elsevier Ltd. All rights reserved.

A critical analysis of the current state of neurosurgery training in Pakistan

PubMed Central

Shamim, M. Shahzad; Tahir, M. Zubair; Godil, Saniya Siraj; Kumar, Rajesh; Siddiqui, Arshad Ali

2011-01-01

Objective: To observe interdepartmental variation in the availability of resources and academic activities within the various neurosurgery programs of Pakistan. Methods: This was a proforma-based survey of neurosurgery trainees and young neurosurgeons of Pakistan, looking at the academic infrastructure and output of their programs. The proforma was filled by 36 respondents from 11 neurosurgery centers of the country. All these centers were accredited for neurosurgery training in Pakistan. Results: Out of the 36 respondents, 30 were completing a Fellowship training (FCPS) and six were enrolled for a Master in Surgery (MS) program. About 80% of the participants used the Youman's Textbook of Neurosurgery as a reference book. Only 40% of the candidates had access to more than one indexed neurosurgery journal. Structured academic sessions (e.g., journal clubs and neuropathology meetings) were lacking in a majority of the training institutes, 95% of the trainees had no microsurgical laboratory experience, and modern neurosurgical tools (frameless neuronavigation system, neuroendoscopy) were in use at a few centers only. Conclusion: Neurosurgery training in Pakistan is not uniform and wide variations exist between the programs at the centers evaluated. We recommend exchange programs between centers at national and international levels, to allow trainees to gain first-hand exposure to training components not available in their own center. PMID:22276237

Automatized set-up procedure for transcranial magnetic stimulation protocols.

PubMed

Harquel, S; Diard, J; Raffin, E; Passera, B; Dall'Igna, G; Marendaz, C; David, O; Chauvin, A

2017-06-01

Transcranial Magnetic Stimulation (TMS) established itself as a powerful technique for probing and treating the human brain. Major technological evolutions, such as neuronavigation and robotized systems, have continuously increased the spatial reliability and reproducibility of TMS, by minimizing the influence of human and experimental factors. However, there is still a lack of efficient set-up procedure, which prevents the automation of TMS protocols. For example, the set-up procedure for defining the stimulation intensity specific to each subject is classically done manually by experienced practitioners, by assessing the motor cortical excitability level over the motor hotspot (HS) of a targeted muscle. This is time-consuming and introduces experimental variability. Therefore, we developed a probabilistic Bayesian model (AutoHS) that automatically identifies the HS position. Using virtual and real experiments, we compared the efficacy of the manual and automated procedures. AutoHS appeared to be more reproducible, faster, and at least as reliable as classical manual procedures. By combining AutoHS with robotized TMS and automated motor threshold estimation methods, our approach constitutes the first fully automated set-up procedure for TMS protocols. The use of this procedure decreases inter-experimenter variability while facilitating the handling of TMS protocols used for research and clinical routine. Copyright © 2017 Elsevier Inc. All rights reserved.

Augmented reality in the surgery of cerebral aneurysms: a technical report.

PubMed

Cabrilo, Ivan; Bijlenga, Philippe; Schaller, Karl

2014-06-01

Augmented reality is the overlay of computer-generated images on real-world structures. It has previously been used for image guidance during surgical procedures, but it has never been used in the surgery of cerebral aneurysms. To report our experience of cerebral aneurysm surgery aided by augmented reality. Twenty-eight patients with 39 unruptured aneurysms were operated on in a prospective manner with augmented reality. Preoperative 3-dimensional image data sets (angio-magnetic resonance imaging, angio-computed tomography, and 3-dimensional digital subtraction angiography) were used to create virtual segmentations of patients' vessels, aneurysms, aneurysm necks, skulls, and heads. These images were injected intraoperatively into the eyepiece of the operating microscope. An example case of an unruptured posterior communicating artery aneurysm clipping is illustrated in a video. The described operating procedure allowed continuous monitoring of the accuracy of patient registration with neuronavigation data and assisted in the performance of tailored surgical approaches and optimal clipping with minimized exposition. Augmented reality may add to the performance of a minimally invasive approach, although further studies need to be performed to evaluate whether certain groups of aneurysms are more likely to benefit from it. Further technological development is required to improve its user friendliness.

Knowledge modeling in image-guided neurosurgery: application in understanding intraoperative brain shift

NASA Astrophysics Data System (ADS)

Cohen-Adad, Julien; Paul, Perrine; Morandi, Xavier; Jannin, Pierre

2006-03-01

During an image-guided neurosurgery procedure, the neuronavigation system is subject to inaccuracy because of anatomical deformations which induce a gap between the preoperative images and their anatomical reality. Thus, the objective of many research teams is to succeed in quantifying these deformations in order to update preoperative images. Anatomical intraoperative deformations correspond to a complex spatio-temporal phenomenon. Our objective is to identify the parameters implicated in these deformations and to use these parameters as constrains for systems dedicated to updating preoperative images. In order to identify these parameters of deformation we followed the iterative methodology used for cognitive system conception: identification, conceptualization, formalization, implementation and validation. A state of the art about cortical deformations has been established in order to identify relevant parameters probably involved in the deformations. As a first step, 30 parameters have been identified and described following an ontological approach. They were formalized into a Unified Modeling Language (UML) class diagram. We implemented that model into a web-based application in order to fill a database. Two surgical cases have been studied at this moment. After having entered enough surgical cases for data mining purposes, we expect to identify the most relevant and influential parameters and to gain a better ability to understand the deformation phenomenon. This original approach is part of a global system aiming at quantifying and correcting anatomical deformations.

Neuroimaging evaluation in refractory epilepsy

PubMed Central

Granados, Ana M; Orejuela, Juan F

2015-01-01

Purpose To describe the application of neuroimaging analysis, compared to neuropsychological tests and video-electroencephalogram, for the evaluation of refractory epilepsy in a reference centre in Cali, Colombia. Methods Between March 2013 and November 2014, 29 patients, 19 men and 10 women, aged 9–65 years and with refractory epilepsy, were assessed by structural and functional magnetic resonance imaging while performing tasks related to language, verbal and non-verbal memory. Also, volumetric evaluation was performed. A 1.5 Tesla magnetic resonance imaging scanner was used in all cases. Results Neuroimaging evaluation identified 13 patients with mesial temporal sclerosis. The remaining patients were classified as: 10 patients with neoplastic masses, two patients with cortical atrophy, two patients with scarring lesions and two patients with non-structural aetiology. Among patients with mesial temporal sclerosis, comparison between techniques for lateralising the epileptogenic foci was made; the κ index between functional magnetic resonance imaging and hippocampi volumetry was κ = 1.00, agreement between neuroimaging and video-electroencephalogram was good (κ = 0.78) and comparison with a neuropsychological test was mild (κ = 0.24). Conclusions Neuroimaging studies allow the assessment of functional and structural damage related to epileptogenic lesions and foci, and are helpful to select surgical treatment, conduct intraoperative neuronavigation techniques, predict surgical deficits and evaluate patient recovery. PMID:26427897

[Operating rooms during the second half of the 20th century and its change with surgical advances].

PubMed

Steimle, Raoul H

2011-01-01

With the rise of new specialities after the World War, the number of OP rooms increases. They became gathered on the basement of buildings near the central sterilisation. To enter the OP room, everyone passes through the dressing "sas". "Slippers", uniforms, gloves and many supplies are now for single-use. Electrified operating tables with their own accessories became very useful. Air conditioning is appreciated too in our countries. The operating microscope for ORL, ophthalmology and neurosurgery is used by every one. In cardiology the coronary revascularisation being common stuff, cardiac transplantation (1967) and open-heart surgery received special attention. Vascular surgeons are dedicated to arteritiden, implants, and aortic aneurysms. Urology is focused on renal transplants (since 1959), and more recently on lithotrity and coelioscopic prostatectomy. The coeliosurgery conquered the abdominal pathology and the endoscopic techniques became current. In neurosurgery, stereotaxy to treat parkinson's disease is not used so often since Levodopa exists. But it is still useful to implant brain-stimulating electrodes for refractory parkinson's cases, some other dyskinesias, mental troubles or epilepsies. The neuronavigation brought new possibilities. At century's end, ambulatory surgery reduces surgical costs. Bigger and multidisciplinary theatres are now preferred. The open-heart surgery assisted by computer and robotics is evolving. Finally, we recall OP room accidents, which are not directly dealing with the operation.

Functional magnetic resonance imaging (fMRI)-aided therapeutics of Chinese speech area-related lesions: screening of fMRI-stimulating mode and its clinical applications.

PubMed

Wu, Nan; Xie, Bing; Wu, Guo-Cai; Lan, Chuan; Wang, Jian; Feng, Hua

2010-01-01

Language area-related lesion is a serious issue in neurosurgery. Removing the lesion in the language area and at the same time preserving language functions is a great challenge. In this study, we aimed to screen functional magnetic resonance imaging (fMRI) based task types suitable for activation of Broca and Wernicke areas in Chinese population, characterize lesion properties of functional area of Chinese language in brain, and assess the potential of fMRI-guided neuronavigation in clinical applications. Blood oxygen level-dependent fMRI has been used to localize language area prior to operation. We carried out extensive fMRI analyses and conducted operation on patients with lesions in speech area. fMRI tests revealed that the reciting task in Chinese can steadily activate the Broca area, and paragraph comprehension task in Chinese can effectively activate the Wernicke area. Cortical stimulation of patients when being awake during operation validated the sensitivity and accuracy of fMRI. The safe distance between language activation area and removal of the lesion in language area was determined to be about 10 mm. Further investigation suggested that navigation of fMRI combined with diffuse tensor imaging can decrease the incidence of postoperative dysfunction and increase the success rate for complete removal of lesion. Taken together, these findings may be helpful to clinical therapy for language area-related lesions.

Morphological Variations in the Transverse Venous Sinus Anatomy of Dogs and its Relationship to Skull Landmarks.

PubMed

Carreira, L Miguel; Ferreira, A

2016-08-01

We characterized the anatomical morphology of the transverse venous sinus (TVS) of 69 canine adult cadavers belonging to three groups: brachycephalic (B), dolichocephalic (D) and mesaticephalic (M). In addition, we outlined its path over the skull using five classic human craniometric points (CPs): the asterion (ast), the bregma (b), the glabella (g), the stephanion (st) and the pterion (pt). The study aimed to establish anatomical differences in the TVS between groups and in the relationship between the TVS and skull. We found that TVS anatomy and its relationships to skull landmarks vary markedly between the groups, with similar anatomical arrangements in B and M. The TVS length can be ranked as M < B < D (with D being the biggest), whereas the width can be ranked as M < D < B (with B being the widest) with the right side being smaller than the left. In the B and M groups, the TVS assumes a craniocaudal trajectory that is closer to the lateral skull wall than in D, where the TVS presents a caudocranial direction. By documenting the morphological characteristics of the TVS, we can create a set of anatomical references allowing construction of a basic framework to greatly decrease the probability of TVS injury during neuronavigation procedures when supported by a good knowledge of the skull, brain anatomies and their relationships. © 2015 Blackwell Verlag GmbH.

Transsphenoidal Approach in Endoscopic Endonasal Surgery for Skull Base Lesions: What Radiologists and Surgeons Need to Know.

PubMed

García-Garrigós, Elena; Arenas-Jiménez, Juan José; Monjas-Cánovas, Irene; Abarca-Olivas, Javier; Cortés-Vela, Jesús Julián; De La Hoz-Rosa, Javier; Guirau-Rubio, Maria Dolores

2015-01-01

In the last 2 decades, endoscopic endonasal transsphenoidal surgery has become the most popular choice of neurosurgeons and otolaryngologists to treat lesions of the skull base, with minimal invasiveness, lower incidence of complications, and lower morbidity and mortality rates compared with traditional approaches. The transsphenoidal route is the surgical approach of choice for most sellar tumors because of the relationship of the sphenoid bone to the nasal cavity below and the pituitary gland above. More recently, extended approaches have expanded the indications for transsphenoidal surgery by using different corridors leading to specific target areas, from the crista galli to the spinomedullary junction. Computer-assisted surgery is an evolving technology that allows real-time anatomic navigation during endoscopic surgery by linking preoperative triplanar radiologic images and intraoperative endoscopic views, thus helping the surgeon avoid damage to vital structures. Preoperative computed tomography is the preferred modality to show bone landmarks and vascular structures. Radiologists play an important role in surgical planning by reporting extension of sphenoid pneumatization, recesses and septations of the sinus, and other relevant anatomic variants. Radiologists should understand the relationships of the sphenoid bone and skull base structures, anatomic variants, and image-guided neuronavigation techniques to prevent surgical complications and allow effective treatment of skull base lesions with the endoscopic endonasal transsphenoidal approach. ©RSNA, 2015.

Effect of inter-train interval on the induction of repetition suppression of motor-evoked potentials using transcranial magnetic stimulation.

PubMed

Pitkänen, Minna; Kallioniemi, Elisa; Julkunen, Petro

2017-01-01

Repetition suppression (RS) is evident as a weakened response to repeated stimuli after the initial response. RS has been demonstrated in motor-evoked potentials (MEPs) induced with transcranial magnetic stimulation (TMS). Here, we investigated the effect of inter-train interval (ITI) on the induction of RS of MEPs with the attempt to optimize the investigative protocols. Trains of TMS pulses, targeted to the primary motor cortex by neuronavigation, were applied at a stimulation intensity of 120% of the resting motor threshold. The stimulus trains included either four or twenty pulses with an inter-stimulus interval (ISI) of 1 s. The ITI was here defined as the interval between the last pulse in a train and the first pulse in the next train; the ITIs used here were 1, 3, 4, 6, 7, 12, and 17 s. RS was observed with all ITIs except with the ITI of 1 s, in which the ITI was equal to ISI. RS was more pronounced with longer ITIs. Shorter ITIs may not allow sufficient time for a return to baseline. RS may reflect a startle-like response to the first pulse of a train followed by habituation. Longer ITIs may allow more recovery time and in turn demonstrate greater RS. Our results indicate that RS can be studied with confidence at relatively short ITIs of 6 s and above.

Need for surgical treatment of epilepsy and excision of tumors and post-traumatic epileptogenic lesions in Kinshasa, RDC.

PubMed

Ntsambi-Eba, G; Beltchika Kalubye, A; Kalala Okito, J P

2017-11-01

Surgery is a treatment to consider in epilepsy when the condition is refractory or epileptic events are related to a clearly identified brain abnormality. The tropical climate of the DRC explains the high risk of epilepsy and the potentially large number of refractory cases. The number of patients with epilepsy in Kinshasa is estimated to be at least 120 000, and almost one third may be refractory. Hence, the need to integrate the use of surgery in the treatment of this disease. Most neurosurgical techniques used for treating epilepsy are practiced with a neurosurgical microscope and neuronavigation. In most developing countries, neither the material conditions for optimum realization of these surgical techniques nor the equipment for epilepsy investigation are close to fully available. Nonetheless, the selection of a large number of patients for surgery often does not require the use of all these explorations.The current availability in Kinshasa of the equipment for the basic investigation of epilepsy, such as EEG and MRI instruments, and the experience of the local neurological/neurosurgical team together make it possible to diagnose this pathology and treat it surgically when necessary. The creation of a multidisciplinary team for epilepsy will enable the selection of candidates who can most effectively benefit from surgical treatment. This surgery should focus initially on well circumscribed lesions that do not require sophisticated methods of investigation and can be removed relatively easily, with a high probability of seizure suppression.

Behavioural and neurofunctional impact of transcranial direct current stimulation on somatosensory learning.

PubMed

Hilgenstock, Raphael; Weiss, Thomas; Huonker, Ralph; Witte, Otto W

2016-04-01

We investigated the effect of repeated delivery of anodal transcranial direct current stimulation (tDCS) on somatosensory performance and long-term learning. Over the course of five days, tDCS was applied to the primary somatosensory cortex (S1) by means of neuronavigation employing magnetencephalography (MEG). Compared to its sham application, tDCS promoted tactile learning by reducing the two-point discrimination threshold assessed by the grating orientation task (GOT) primarily by affecting intersessional changes in performance. These results were accompanied by alterations in the neurofunctional organization of the brain, as revealed by functional magnetic resonance imaging conducted prior to the study, at the fifth day of tDCS delivery and four weeks after the last application of tDCS. A decrease in activation at the primary site of anodal tDCS delivery in the left S1 along retention of superior tactile acuity was observed at follow-up four weeks after the application of tDCS. Thus, we demonstrate long-term effects that repeated tDCS imposes on somatosensory functioning. This is the first study to provide insight into the mode of operation of tDCS on the brain's response to long-term perceptual learning, adding an important piece of evidence from the domain of non-invasive brain stimulation to show that functional changes detectable by fMRI in primary sensory cortices participate in perceptual learning. © 2016 Wiley Periodicals, Inc.

Evaluation of Language Function under Awake Craniotomy

PubMed Central

KANNO, Aya; MIKUNI, Nobuhiro

2015-01-01

Awake craniotomy is the only established way to assess patients’ language functions intraoperatively and to contribute to their preservation, if necessary. Recent guidelines have enabled the approach to be used widely, effectively, and safely. Non-invasive brain functional imaging techniques, including functional magnetic resonance imaging and diffusion tensor imaging, have been used preoperatively to identify brain functional regions corresponding to language, and their accuracy has increased year by year. In addition, the use of neuronavigation that incorporates this preoperative information has made it possible to identify the positional relationships between the lesion and functional regions involved in language, conduct functional brain mapping in the awake state with electrical stimulation, and intraoperatively assess nerve function in real time when resecting the lesion. This article outlines the history of awake craniotomy, the current state of pre- and intraoperative evaluation of language function, and the clinical usefulness of such functional evaluation. When evaluating patients’ language functions during awake craniotomy, given the various intraoperative stresses involved, it is necessary to carefully select the tasks to be undertaken, quickly perform all examinations, and promptly evaluate the results. As language functions involve both input and output, they are strongly affected by patients’ preoperative cognitive function, degree of intraoperative wakefulness and fatigue, the ability to produce verbal articulations and utterances, as well as perform synergic movement. Therefore, it is essential to appropriately assess the reproducibility of language function evaluation using awake craniotomy techniques. PMID:25925758

Adaptability and reproducibility of a memory disruption rTMS protocol in the PharmaCog IMI European project.

PubMed

Martin-Trias, Pablo; Lanteaume, Laura; Solana, Elisabeth; Cassé-Perrot, Catherine; Fernández-Cabello, Sara; Babiloni, Claudio; Marzano, Nicola; Junqué, Carme; Rossini, Paolo Maria; Micallef, Joëlle; Truillet, Romain; Charles, Estelle; Jouve, Elisabeth; Bordet, Régis; Santamaria, Joan; Jovicich, Jorge; Rossi, Simone; Pascual-Leone, Alvaro; Blin, Olivier; Richardson, Jill; Bartrés-Faz, David

2018-06-19

Transcranial magnetic stimulation (TMS) can interfere with cognitive processes, such as transiently impairing memory. As part of a multi-center European project, we investigated the adaptability and reproducibility of a previously published TMS memory interfering protocol in two centers using EEG or fMRI scenarios. Participants were invited to attend three experimental sessions on different days, with sham repetitive TMS (rTMS) applied on day 1 and real rTMS on days 2 and 3. Sixty-eight healthy young men were included. On each experimental day, volunteers were instructed to remember visual pictures while receiving neuronavigated rTMS trains (20 Hz, 900 ms) during picture encoding at the left dorsolateral prefrontal cortex (L-DLPFC) and the vertex. Mixed ANOVA model analyses were performed. rTMS to the L-DLPFC significantly disrupted recognition memory on experimental day 2. No differences were found between centers or between fMRI and EEG recordings. Subjects with lower baseline memory performances were more susceptible to TMS disruption. No stability of TMS-induced memory interference could be demonstrated on day 3. Our data suggests that adapted cognitive rTMS protocols can be implemented in multi-center studies incorporating standardized experimental procedures. However, our center and modality effects analyses lacked sufficient statistical power, hence highlighting the need to conduct further studies with larger samples. In addition, inter and intra-subject variability in response to TMS might limit its application in crossover or longitudinal studies.

Single slice US-MRI registration for neurosurgical MRI-guided US

NASA Astrophysics Data System (ADS)

Pardasani, Utsav; Baxter, John S. H.; Peters, Terry M.; Khan, Ali R.

2016-03-01

Image-based ultrasound to magnetic resonance image (US-MRI) registration can be an invaluable tool in image-guided neuronavigation systems. State-of-the-art commercial and research systems utilize image-based registration to assist in functions such as brain-shift correction, image fusion, and probe calibration. Since traditional US-MRI registration techniques use reconstructed US volumes or a series of tracked US slices, the functionality of this approach can be compromised by the limitations of optical or magnetic tracking systems in the neurosurgical operating room. These drawbacks include ergonomic issues, line-of-sight/magnetic interference, and maintenance of the sterile field. For those seeking a US vendor-agnostic system, these issues are compounded with the challenge of instrumenting the probe without permanent modification and calibrating the probe face to the tracking tool. To address these challenges, this paper explores the feasibility of a real-time US-MRI volume registration in a small virtual craniotomy site using a single slice. We employ the Linear Correlation of Linear Combination (LC2) similarity metric in its patch-based form on data from MNI's Brain Images for Tumour Evaluation (BITE) dataset as a PyCUDA enabled Python module in Slicer. By retaining the original orientation information, we are able to improve on the poses using this approach. To further assist the challenge of US-MRI registration, we also present the BOXLC2 metric which demonstrates a speed improvement to LC2, while retaining a similar accuracy in this context.

Neural networks improve brain cancer detection with Raman spectroscopy in the presence of light artifacts

NASA Astrophysics Data System (ADS)

Jermyn, Michael; Desroches, Joannie; Mercier, Jeanne; St-Arnaud, Karl; Guiot, Marie-Christine; Petrecca, Kevin; Leblond, Frederic

2016-03-01

It is often difficult to identify cancer tissue during brain cancer (glioma) surgery. Gliomas invade into areas of normal brain, and this cancer invasion is frequently not detected using standard preoperative magnetic resonance imaging (MRI). This results in enduring invasive cancer following surgery and leads to recurrence. A hand-held Raman spectroscopy is able to rapidly detect cancer invasion in patients with grade 2-4 gliomas. However, ambient light sources can produce spectral artifacts which inhibit the ability to distinguish between cancer and normal tissue using the spectral information available. To address this issue, we have demonstrated that artificial neural networks (ANN) can accurately classify invasive cancer versus normal brain tissue, even when including measurements with significant spectral artifacts from external light sources. The non-parametric and adaptive model used by ANN makes it suitable for detecting complex non-linear spectral characteristics associated with different tissues and the confounding presence of light artifacts. The use of ANN for brain cancer detection with Raman spectroscopy, in the presence of light artifacts, improves the robustness and clinical translation potential for intraoperative use. Integration with the neurosurgical workflow is facilitated by accounting for the effect of light artifacts which may occur, due to operating room lights, neuronavigation systems, windows, or other light sources. The ability to rapidly detect invasive brain cancer under these conditions may reduce residual cancer remaining after surgery, and thereby improve patient survival.

Evaluation of Language Function under Awake Craniotomy.

PubMed

Kanno, Aya; Mikuni, Nobuhiro

2015-01-01

Awake craniotomy is the only established way to assess patients' language functions intraoperatively and to contribute to their preservation, if necessary. Recent guidelines have enabled the approach to be used widely, effectively, and safely. Non-invasive brain functional imaging techniques, including functional magnetic resonance imaging and diffusion tensor imaging, have been used preoperatively to identify brain functional regions corresponding to language, and their accuracy has increased year by year. In addition, the use of neuronavigation that incorporates this preoperative information has made it possible to identify the positional relationships between the lesion and functional regions involved in language, conduct functional brain mapping in the awake state with electrical stimulation, and intraoperatively assess nerve function in real time when resecting the lesion. This article outlines the history of awake craniotomy, the current state of pre- and intraoperative evaluation of language function, and the clinical usefulness of such functional evaluation. When evaluating patients' language functions during awake craniotomy, given the various intraoperative stresses involved, it is necessary to carefully select the tasks to be undertaken, quickly perform all examinations, and promptly evaluate the results. As language functions involve both input and output, they are strongly affected by patients' preoperative cognitive function, degree of intraoperative wakefulness and fatigue, the ability to produce verbal articulations and utterances, as well as perform synergic movement. Therefore, it is essential to appropriately assess the reproducibility of language function evaluation using awake craniotomy techniques.

Intraoperative neurophysiological monitoring of the cortico-spinal tract in image-guided mini-invasive neurosurgery.

PubMed

Cordella, Roberto; Acerbi, Francesco; Broggi, Morgan; Vailati, Davide; Nazzi, Vittoria; Schiariti, Marco; Tringali, Giovanni; Ferroli, Paolo; Franzini, Angelo; Broggi, Giovanni

2013-06-01

To evaluate the role of intraoperative neurophysiological monitoring in image-guided mini-invasive neurosurgery. Twenty-one patients were operated under general anaesthesia with the aid of multimodal intraoperative neurophysiological monitoring to remove supratentorials tumors closely related to the cortico-spinal tract. Pre-operative assessment included fMRI scans and tractography that were uploaded into the intraoperative neuro-navigation system. Monitoring consisted in simultaneously recording EEG, electrocorticography, transcranial and direct motor evoked potentials (tMEP and dMEP), somatosensory evoked potentials and subcortical stimulation during the whole procedures. The recording of all the electrophysiological signals was possible in all procedures. SSEP guided the positioning of the strip electrode over the motor cortex (N20 phase inversion) that was used to evoke dMEP and monitor the lower limb motor responses; subcortical stimulation to unveil the spatial relationship between the tumors and motor fibers. Four patients had transient worsening of the symptoms, but only two had a long-term worsening, although not severe, of the pre-op clinical status. Intraoperative neurophysiology has a great value in mini-invasive neurosurgery, especially because the motor cortex is not exposed, consequently it cannot be directly mapped. This report describes a valuable scheme making use of as many electrophysiological signals as possible to constantly monitor the motor functions. A useful method to monitor motor functions in mini-invasive neurosurgery was described. Copyright © 2012 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Robotic autopositioning of the operating microscope.

PubMed

Oppenlander, Mark E; Chowdhry, Shakeel A; Merkl, Brandon; Hattendorf, Guido M; Nakaji, Peter; Spetzler, Robert F

2014-06-01

Use of the operating microscope has become pervasive since its introduction to the neurosurgical world. Neuronavigation fused with the operating microscope has allowed accurate correlation of the focal point of the microscope and its location on the downloaded imaging study. However, the robotic ability of the Pentero microscope has not been utilized to orient the angle of the microscope or to change its focal length to hone in on a predefined target. To report a novel technology that allows automatic positioning of the operating microscope onto a set target and utilization of a planned trajectory, either determined with the StealthStation S7 by using preoperative imaging or intraoperatively with the microscope. By utilizing the current motorized capabilities of the Zeiss OPMI Pentero microscope, a robotic autopositioning feature was developed in collaboration with Surgical Technologies, Medtronic, Inc. (StealthStation S7). The system is currently being tested at the Barrow Neurological Institute. Three options were developed for automatically positioning the microscope: AutoLock Current Point, Align Parallel to Plan, and Point to Plan Target. These options allow the microscope to pivot around the lesion, hover in a set plane parallel to the determined trajectory, or rotate and point to a set target point, respectively. Integration of automatic microscope positioning into the operative workflow has potential to increase operative efficacy and safety. This technology is best suited for precise trajectories and entry points into deep-seated lesions.

Establishment of Next-Generation Neurosurgery Research and Training Laboratory with Integrated Human Performance Monitoring.

PubMed

Bernardo, Antonio

2017-10-01

Quality of neurosurgical care and patient outcomes are inextricably linked to surgical and technical proficiency and a thorough working knowledge of microsurgical anatomy. Neurosurgical laboratory-based cadaveric training is essential for the development and refinement of technical skills before their use on a living patient. Recent biotechnological advances including 3-dimensional (3D) microscopy and endoscopy, 3D printing, virtual reality, surgical simulation, surgical robotics, and advanced neuroimaging have proved to reduce the learning curve, improve conceptual understanding of complex anatomy, and enhance visuospatial skills in neurosurgical training. Until recently, few means have allowed surgeons to obtain integrated surgical and technological training in an operating room setting. We report on a new model, currently in use at our institution, for technologically integrated surgical training and innovation using a next-generation microneurosurgery skull base laboratory designed to recreate the setting of a working operating room. Each workstation is equipped with a 3D surgical microscope, 3D endoscope, surgical drills, operating table with a Mayfield head holder, and a complete set of microsurgical tools. The laboratory also houses a neuronavigation system, a surgical robotic, a surgical planning system, 3D visualization, virtual reality, and computerized simulation for training of surgical procedures and visuospatial skills. In addition, the laboratory is equipped with neurophysiological monitoring equipment in order to conduct research into human factors in surgery and the respective roles of workload and fatigue on surgeons' performance. Copyright © 2017 Elsevier Inc. All rights reserved.

Robotic long-distance telementoring in neurosurgery.

PubMed

Mendez, Ivar; Hill, Ron; Clarke, David; Kolyvas, George; Walling, Simon

2005-03-01

To test the feasibility of long-distance telementoring in neurosurgery by providing subspecialized expertise in real time to another neurosurgeon performing a surgical procedure in a remote location. A robotic telecollaboration system (Socrates; Computer Motion, Inc., Santa Barbara, CA) capable of controlling the movements of a robotic arm, of handling two-way video, and of audio communication as well as transmission of neuronavigational data from the remote operating room was used for the telementoring procedures. Four integrated services digital network lines with a total speed of transmission of 512 kilobytes per second provided telecommunications between a large academic center (Halifax, Nova Scotia) and a community-based center (Saint John, New Brunswick) located 400 km away. Long-distance telementoring was used in three craniotomies for brain tumors, a craniotomy for an arteriovenous malformation, a carotid endarterectomy, and a lumbar laminectomy. There were no surgical complications during the procedures, and all patients had uneventful outcomes. The neurosurgeons in the remote location believed that the input from the mentors was useful in all of the cases and was crucial in the removal of a mesial temporal lobe glioma and resection of an occipital arteriovenous malformation. Our initial experience with long-distance robotic-assisted telementoring in six cases indicates that telementoring is feasible, reliable, and safe. Although still in its infancy, telementoring has the potential to improve surgical care, to enhance neurosurgical training, and to have a major impact on the delivery of neurosurgical services throughout the world.

Computerized lateral endoscopic approach to invertebral bodies

NASA Astrophysics Data System (ADS)

Abbasi, Hamid R.; Hariri, Sanaz; Kim, Daniel; Shahidi, Ramin; Steinberg, Gary

2001-05-01

Spinal surgery is often necessary to ease back pain symptoms. Neuronavigation (NN) allows the surgeon to localize the position of his instruments in 3D using pre- operative CT scans registered to intra-operative marker positions in cranial surgeries. However, this tool is unavailable in spinal surgeries for a variety of reasons. For example, because of the spine's many degrees of freedom and flexibility, the geometric relationship of the skin to the internal spinal anatomy is not fixed. Guided by the currently available imperfect 2D images, it is difficult for the surgeon to correct a patient's spinal anomaly; thus surgical relief of back pain is often only temporary. The Image Guidance Laborator's (IGL) goal is to combine the direct optical control of traditional endoscopy with the 3D orientation of NN. This powerful tool requires registration of the patient's anatomy to the surgical navigation system using internal landmarks rather than skin markers. Pre- operative CT scans matched with intraoperative fluoroscopic images can overcome the problem of spinal movement in NN registration. The combination of endoscopy with fluoroscopic registration of vertebral bodies in a NN system provides a 3D intra-operative navigational system for spinal neurosurgery to visualize the internal surgical environment from any orientation in real time. The accuracy of this system integration is being evaluated by assessing the success of nucleotomies and marker implantations guided by NN-registered endoscopy.

Design, implementation and accuracy of a prototype for medical augmented reality.

PubMed

Pandya, Abhilash; Siadat, Mohammad-Reza; Auner, Greg

2005-01-01

This paper is focused on prototype development and accuracy evaluation of a medical Augmented Reality (AR) system. The accuracy of such a system is of critical importance for medical use, and is hence considered in detail. We analyze the individual error contributions and the system accuracy of the prototype. A passive articulated arm is used to track a calibrated end-effector-mounted video camera. The live video view is superimposed in real time with the synchronized graphical view of CT-derived segmented object(s) of interest within a phantom skull. The AR accuracy mostly depends on the accuracy of the tracking technology, the registration procedure, the camera calibration, and the image scanning device (e.g., a CT or MRI scanner). The accuracy of the Microscribe arm was measured to be 0.87 mm. After mounting the camera on the tracking device, the AR accuracy was measured to be 2.74 mm on average (standard deviation = 0.81 mm). After using data from a 2-mm-thick CT scan, the AR error remained essentially the same at an average of 2.75 mm (standard deviation = 1.19 mm). For neurosurgery, the acceptable error is approximately 2-3 mm, and our prototype approaches these accuracy requirements. The accuracy could be increased with a higher-fidelity tracking system and improved calibration and object registration. The design and methods of this prototype device can be extrapolated to current medical robotics (due to the kinematic similarity) and neuronavigation systems.

Where and When to Cut? Fluorescein Guidance for Brain Stem and Spinal Cord Tumor Surgery-Technical Note.

PubMed

Molina, Eric Suero; Stummer, Walter

2017-12-29

Spinal cord and brain stem lesions require a judicious approach with an optimized trajectory due to a clustering of functions on their surfaces. Intraoperative mapping helps locate function. To confidently locate such lesions, neuronavigation alone lacks the desired accuracy and is of limited use in the spinal cord. To evaluate the clinical value of fluoresceins for initial delineation of such critically located lesions. We evaluated fluorescein guidance in the surgical resection of lesions with blood-brain barrier disruption demonstrating contrast enhancement in magnet resonance imaging in the spinal cord and in the brain stem in 3 different patients. Two patients harbored a diffuse cervical and thoracic spinal cord lesion, respectively. Another patient suffered metastatic lesions in the brain stem and at the floor of the fourth ventricle. Low-dose fluorescein (4 mg/kg body weight) was applied after anesthesia induction and visualized using the Zeiss Pentero 900 Yellow560 filter (Carl Zeiss, Oberkochen, Germany). Fluorescein was helpful for locating lesions and for defining the best possible trajectory. During resection, however, we found unspecific propagation of fluorescein within the brain stem up to 6 mm within 3 h after application. As these lesions were otherwise distinguishable from surrounding tissue, monitoring resection was not an issue. Fluorescein guidance is a feasible tool for defining surgical entry zones when aiming for surgical removal of spinal cord and brain stem lesions. Unselective fluorescein extravasation cautions against using such methodology for monitoring completeness of resection. Providing the right timing, a window of pseudoselectivity could increase fluoresceins' clinical value in these cases. © Congress of Neurological Surgeons 2017.

Clinical Application of an Open-Source 3D Volume Rendering Software to Neurosurgical Approaches.

PubMed

Fernandes de Oliveira Santos, Bruno; Silva da Costa, Marcos Devanir; Centeno, Ricardo Silva; Cavalheiro, Sergio; Antônio de Paiva Neto, Manoel; Lawton, Michael T; Chaddad-Neto, Feres

2018-02-01

Preoperative recognition of the anatomic individualities of each patient can help to achieve more precise and less invasive approaches. It also may help to anticipate potential complications and intraoperative difficulties. Here we describe the use, accuracy, and precision of a free tool for planning microsurgical approaches using 3-dimensional (3D) reconstructions from magnetic resonance imaging (MRI). We used the 3D volume rendering tool of a free open-source software program for 3D reconstruction of images of surgical sites obtained by MRI volumetric acquisition. We recorded anatomic reference points, such as the sulcus and gyrus, and vascularization patterns for intraoperative localization of lesions. Lesion locations were confirmed during surgery by intraoperative ultrasound and/or electrocorticography and later by postoperative MRI. Between August 2015 and September 2016, a total of 23 surgeries were performed using this technique for 9 low-grade gliomas, 7 high-grade gliomas, 4 cortical dysplasias, and 3 arteriovenous malformations. The technique helped delineate lesions with an overall accuracy of 2.6 ± 1.0 mm. 3D reconstructions were successfully performed in all patients, and images showed sulcus, gyrus, and venous patterns corresponding to the intraoperative images. All lesion areas were confirmed both intraoperatively and at the postoperative evaluation. With the technique described herein, it was possible to successfully perform 3D reconstruction of the cortical surface. This reconstruction tool may serve as an adjunct to neuronavigation systems or may be used alone when such a system is unavailable. Copyright © 2017 Elsevier Inc. All rights reserved.

Rapid and minimum invasive functional brain mapping by real-time visualization of high gamma activity during awake craniotomy.

PubMed

Ogawa, Hiroshi; Kamada, Kyousuke; Kapeller, Christoph; Hiroshima, Satoru; Prueckl, Robert; Guger, Christoph

2014-11-01

Electrocortical stimulation (ECS) is the gold standard for functional brain mapping during an awake craniotomy. The critical issue is to set aside enough time to identify eloquent cortices by ECS. High gamma activity (HGA) ranging between 80 and 120 Hz on electrocorticogram is assumed to reflect localized cortical processing. In this report, we used real-time HGA mapping and functional neuronavigation integrated with functional magnetic resonance imaging (fMRI) for rapid and reliable identification of motor and language functions. Four patients with intra-axial tumors in their dominant hemisphere underwent preoperative fMRI and lesion resection with an awake craniotomy. All patients showed significant fMRI activation evoked by motor and language tasks. During the craniotomy, we recorded electrocorticogram activity by placing subdural grids directly on the exposed brain surface. Each patient performed motor and language tasks and demonstrated real-time HGA dynamics in hand motor areas and parts of the inferior frontal gyrus. Sensitivity and specificity of HGA mapping were 100% compared with ECS mapping in the frontal lobe, which suggested HGA mapping precisely indicated eloquent cortices. We found different HGA dynamics of language tasks in frontal and temporal regions. Specificities of the motor and language-fMRI did not reach 85%. The results of HGA mapping was mostly consistent with those of ECS mapping, although fMRI tended to overestimate functional areas. This novel technique enables rapid and accurate identification of motor and frontal language areas. Furthermore, real-time HGA mapping sheds light on underlying physiological mechanisms related to human brain functions. Copyright © 2014 Elsevier Inc. All rights reserved.

Computers and neurosurgery.

PubMed

Shaikhouni, Ammar; Elder, J Bradley

2012-11-01

At the turn of the twentieth century, the only computational device used in neurosurgical procedures was the brain of the surgeon. Today, most neurosurgical procedures rely at least in part on the use of a computer to help perform surgeries accurately and safely. The techniques that revolutionized neurosurgery were mostly developed after the 1950s. Just before that era, the transistor was invented in the late 1940s, and the integrated circuit was invented in the late 1950s. During this time, the first automated, programmable computational machines were introduced. The rapid progress in the field of neurosurgery not only occurred hand in hand with the development of modern computers, but one also can state that modern neurosurgery would not exist without computers. The focus of this article is the impact modern computers have had on the practice of neurosurgery. Neuroimaging, neuronavigation, and neuromodulation are examples of tools in the armamentarium of the modern neurosurgeon that owe each step in their evolution to progress made in computer technology. Advances in computer technology central to innovations in these fields are highlighted, with particular attention to neuroimaging. Developments over the last 10 years in areas of sensors and robotics that promise to transform the practice of neurosurgery further are discussed. Potential impacts of advances in computers related to neurosurgery in developing countries and underserved regions are also discussed. As this article illustrates, the computer, with its underlying and related technologies, is central to advances in neurosurgery over the last half century. Copyright © 2012 Elsevier Inc. All rights reserved.

Direct evidence from intraoperative electrocortical stimulation indicates shared and distinct speech production center between Chinese and English languages.

PubMed

Wu, Jinsong; Lu, Junfeng; Zhang, Han; Zhang, Jie; Yao, Chengjun; Zhuang, Dongxiao; Qiu, Tianming; Guo, Qihao; Hu, Xiaobing; Mao, Ying; Zhou, Liangfu

2015-12-01

Chinese processing has been suggested involving distinct brain areas from English. However, current functional localization studies on Chinese speech processing use mostly "indirect" techniques such as functional magnetic resonance imaging and electroencephalography, lacking direct evidence by means of electrocortical recording. In this study, awake craniotomies in 66 Chinese-speaking glioma patients provide a unique opportunity to directly map eloquent language areas. Intraoperative electrocortical stimulation was conducted and the positive sites for speech arrest, anomia, and alexia were identified separately. With help of stereotaxic neuronavigation system and computational modeling, all positive sites elicited by stimulation were integrated and a series of two- and three-dimension Chinese language probability maps were built. We performed statistical comparisons between the Chinese maps and previously derived English maps. While most Chinese speech arrest areas located at typical language production sites (i.e., 50% positive sites in ventral precentral gyrus, 28% in pars opercularis and pars triangularis), which also serve English production, an additional brain area, the left middle frontal gyrus (Brodmann's areas 6/9), was found to be unique in Chinese production (P < 0.05). Moreover, Chinese speakers' inferior ventral precentral gyrus (Brodmann's area 6) was used more than that in English speakers. Our finding suggests that Chinese involves more perisylvian region (extending to left middle frontal gyrus) than English. This is the first time that direct evidence supports cross-cultural neurolinguistics differences in human beings. The Chinese language atlas will also helpful in brain surgery planning for Chinese-speakers. Copyright © 2015 Wiley Periodicals, Inc.

Two-Dimensional High Definition Versus Three-Dimensional Endoscopy in Endonasal Skull Base Surgery: A Comparative Preclinical Study.

PubMed

Rampinelli, Vittorio; Doglietto, Francesco; Mattavelli, Davide; Qiu, Jimmy; Raffetti, Elena; Schreiber, Alberto; Villaret, Andrea Bolzoni; Kucharczyk, Walter; Donato, Francesco; Fontanella, Marco Maria; Nicolai, Piero

2017-09-01

Three-dimensional (3D) endoscopy has been recently introduced in endonasal skull base surgery. Only a relatively limited number of studies have compared it to 2-dimensional, high definition technology. The objective was to compare, in a preclinical setting for endonasal endoscopic surgery, the surgical maneuverability of 2-dimensional, high definition and 3D endoscopy. A group of 68 volunteers, novice and experienced surgeons, were asked to perform 2 tasks, namely simulating grasping and dissection surgical maneuvers, in a model of the nasal cavities. Time to complete the tasks was recorded. A questionnaire to investigate subjective feelings during tasks was filled by each participant. In 25 subjects, the surgeons' movements were continuously tracked by a magnetic-based neuronavigator coupled with dedicated software (ApproachViewer, part of GTx-UHN) and the recorded trajectories were analyzed by comparing jitter, sum of square differences, and funnel index. Total execution time was significantly lower with 3D technology (P < 0.05) in beginners and experts. Questionnaires showed that beginners preferred 3D endoscopy more frequently than experts. A minority (14%) of beginners experienced discomfort with 3D endoscopy. Analysis of jitter showed a trend toward increased effectiveness of surgical maneuvers with 3D endoscopy. Sum of square differences and funnel index analyses documented better values with 3D endoscopy in experts. In a preclinical setting for endonasal skull base surgery, 3D technology appears to confer an advantage in terms of time of execution and precision of surgical maneuvers. Copyright © 2017 Elsevier Inc. All rights reserved.

Screw Placement Accuracy and Outcomes Following O-Arm-Navigated Atlantoaxial Fusion: A Feasibility Study.

PubMed

Smith, Jacob D; Jack, Megan M; Harn, Nicholas R; Bertsch, Judson R; Arnold, Paul M

2016-06-01

Study Design Case series of seven patients. Objective C2 stabilization can be challenging due to the complex anatomy of the upper cervical vertebrae. We describe seven cases of C1-C2 fusion using intraoperative navigation to aid in the screw placement at the atlantoaxial (C1-C2) junction. Methods Between 2011 and 2014, seven patients underwent posterior atlantoaxial fusion using intraoperative frameless stereotactic O-arm Surgical Imaging and StealthStation Surgical Navigation System (Medtronic, Inc., Minneapolis, Minnesota, United States). Outcome measures included screw accuracy, neurologic status, radiation dosing, and surgical complications. Results Four patients had fusion at C1-C2 only, and in the remaining three, fixation extended down to C3 due to anatomical considerations for screw placement recognized on intraoperative imaging. Out of 30 screws placed, all demonstrated minimal divergence from desired placement in either C1 lateral mass, C2 pedicle, or C3 lateral mass. No neurovascular compromise was seen following the use of intraoperative guided screw placement. The average radiation dosing due to intraoperative imaging was 39.0 mGy. All patients were followed for a minimum of 12 months. All patients went on to solid fusion. Conclusion C1-C2 fusion using computed tomography-guided navigation is a safe and effective way to treat atlantoaxial instability. Intraoperative neuronavigation allows for high accuracy of screw placement, limits complications by sparing injury to the critical structures in the upper cervical spine, and can help surgeons make intraoperative decisions regarding complex pathology.

Single Session Low Frequency Left Dorsolateral Prefrontal Transcranial Magnetic Stimulation Changes Neurometabolite Relationships in Healthy Humans

PubMed Central

Bridges, Nathaniel R.; McKinley, Richard A.; Boeke, Danielle; Sherwood, Matthew S.; Parker, Jason G.; McIntire, Lindsey K.; Nelson, Justin M.; Fletchall, Catherine; Alexander, Natasha; McConnell, Amanda; Goodyear, Chuck; Nelson, Jeremy T.

2018-01-01

Background: Dorsolateral prefrontal cortex (DLPFC) low frequency repetitive transcranial magnetic stimulation (LF-rTMS) has shown promise as a treatment and investigative tool in the medical and research communities. Researchers have made significant progress elucidating DLPFC LF-rTMS effects—primarily in individuals with psychiatric disorders. However, more efforts investigating underlying molecular changes and establishing links to functional and behavioral outcomes in healthy humans are needed. Objective: We aimed to quantify neuromolecular changes and relate these to functional changes following a single session of DLPFC LF-rTMS in healthy participants. Methods: Eleven participants received sham-controlled neuronavigated 1 Hz rTMS to the region most activated by a 7-letter Sternberg working memory task (SWMT) within the left DLPFC. We quantified SWMT performance, functional magnetic resonance activation and proton Magnetic resonance spectroscopy (MRS) neurometabolite measure changes before and after stimulation. Results: A single LF-rTMS session was not sufficient to change DLPFC neurometabolite levels and these changes did not correlate with DLPFC activation changes. Real rTMS, however, significantly altered neurometabolite correlations (compared to sham rTMS), both with baseline levels and between the metabolites themselves. Additionally, real rTMS was associated with diminished reaction time (RT) performance improvements and increased activation within the motor, somatosensory and lateral occipital cortices. Conclusion: These results show that a single session of LF-rTMS is sufficient to influence metabolite relationships and causes widespread activation in healthy humans. Investigating correlational relationships may provide insight into mechanisms underlying LF-rTMS. PMID:29632477

A Low-Cost iPhone-Assisted Augmented Reality Solution for the Localization of Intracranial Lesions.

PubMed

Hou, YuanZheng; Ma, LiChao; Zhu, RuYuan; Chen, XiaoLei; Zhang, Jun

2016-01-01

Precise location of intracranial lesions before surgery is important, but occasionally difficult. Modern navigation systems are very helpful, but expensive. A low-cost solution that could locate brain lesions and their surface projections in augmented reality would be beneficial. We used an iPhone to partially achieve this goal, and evaluated its accuracy and feasibility in a clinical neurosurgery setting. We located brain lesions in 35 patients, and using an iPhone, we depicted the lesion's surface projection onto the skin of the head. To assess the accuracy of this method, we pasted computed tomography (CT) markers surrounding the depicted lesion boundaries on the skin onto 15 patients. CT scans were then performed with or without contrast enhancement. The deviations (D) between the CT markers and the actual lesion boundaries were measured. We found that 97.7% of the markers displayed a high accuracy level (D ≤ 5mm). In the remaining 20 patients, we compared our iPhone-based method with a frameless neuronavigation system. Four check points were chosen on the skin surrounding the depicted lesion boundaries, to assess the deviations between the two methods. The integrated offset was calculated according to the deviations at the four check points. We found that for the supratentorial lesions, the medial offset between these two methods was 2.90 mm and the maximum offset was 4.2 mm. This low-cost, image-based, iPhone-assisted, augmented reality solution is technically feasible, and helpful for the localization of some intracranial lesions, especially shallow supratentorial intracranial lesions of moderate size.

Application of image guidance in pituitary surgery

PubMed Central

de Lara, Danielle; Filho, Leo F. S. Ditzel; Prevedello, Daniel M.; Otto, Bradley A.; Carrau, Ricardo L.

2012-01-01

Background: Surgical treatment of pituitary pathologies has evolved along the years, adding safety and decreasing morbidity related to the procedure. Advances in the field of radiology, coupled with stereotactic technology and computer modeling, have culminated in the contemporary and widespread use of image guidance systems, as we know them today. Image guidance navigation has become a frequently used technology that provides continuous three-dimensional information for the accurate performance of neurosurgical procedures. We present a discussion about the application of image guidance in pituitary surgeries. Methods: Major indications for image guidance neuronavigation application in pituitary surgery are presented and demonstrated with illustrative cases. Limitations of this technology are also presented. Results: Patients presenting a history of previous transsphenoidal surgeries, anatomical variances of the sphenoid sinus, tumors with a close relation to the internal carotid arteries, and extrasellar tumors are the most important indications for image guidance in pituitary surgeries. The high cost of the equipment, increased time of surgery due to setup time, and registration and the need of specific training for the operating room personnel could be pointed as limitations of this technology. Conclusion: Intraoperative image guidance systems provide real-time images, increasing surgical accuracy and enabling safe, minimally invasive interventions. However, the use of intraoperative navigation is not a replacement for surgical experience and a systematic knowledge of regional anatomy. It must be recognized as a tool by which the neurosurgeon can reduce the risk associated with surgical approach and treatment of pituitary pathologies. PMID:22826819

Magnetotherapy.

PubMed

Zyss, Tomasz

2008-11-01

Since antiquity, the phenomenon of magnetism has been known, and it has been tried for therapeutic purposes. Through history, people have made use of both natural sources of magnetic fields (magnetic iron ore) and artificial ones (magnets, electromagnets). It was as late as the 19th century that we started to produce time-varying magnetic fields, making numerous observations about its impact on humans, the nervous system included. A majority of these observations were cognitive in nature. There are, however, studies aimed at assessing the therapeutic results of the influence of magnetic fields, particularly of low frequencies. In terms of magnetotherapy with the use of a low-induction magnetic field, there are serious doubts concerning its effectiveness in general, including therapy for mental disorders. The year 1985 witnessed the introduction of transcranial magnetic stimulation (TMS) into medical practice as a diagnostic tool in neurology as well as in basic neurophysiologic and neuropsychological investigations. The 1990s began the epoch of investigations into possible applications of TMS in therapy of mental disorders, particularly depression. This work presents critical remarks and limitations of TMS, such as findings that its effectiveness is not particularly high. The traditional fixed stimulation of a definite area of the patient's head may lead to irritation of structures that, in a specific patient, may not be responsible for the symptoms of depression. The effectiveness could be improved only with the use of neuronavigation and prestimulation via functional neuroimaging diagnostics of the brain, which, however, would make TMS expensive and less practical.

Microsurgical Repair of Ruptured Aneurysms Associated with Moyamoya-Pattern Collateral Vessels of the Middle Cerebral Artery: A Report of Two Cases.

PubMed

Lang, Min; Moore, Nina Z; Witek, Alex M; Kshettry, Varun R; Bain, Mark D

2017-09-01

Patients with Moyamoya or other intracranial steno-occlusive disease are at risk for developing aneurysms associated with flow through collateral vessels. Because these lesions are rare, the optimal management remains unclear. Here, we describe 2 cases of microsurgical repair of ruptured collateral vessel aneurysms associated with middle cerebral artery (MCA) occlusion. The first patient was a 61-year-old man who presented with right frontal and intraventricular hemorrhage. Angiography revealed chronic right M1 occlusion and a 3-mm spherical lenticulostriate aneurysm. The frontal lobe hematoma was evacuated to reveal the aneurysm, which was safely cauterized and resected by coagulating and dividing the lenticulostriate parent vessel. The procedure was carried out with neuronavigation guidance and intraoperative neuromonitoring. The patient was discharged with no neurologic deficits. The second patient was a 53-year-old woman who presented with subarachnoid and intracerebral hemorrhage. Computed tomography angiogram showed a 2-mm saccular MCA aneurysm. Emergency left decompressive hemicraniectomy and hematoma evacuation were performed. The aneurysm, arising from a small collateral type vessel, was safely clipped without complications. Postoperative angiography revealed absence of the superior MCA trunk with a dense network of collateral vessels at the site of the clipped aneurysm. The patient recovered well and was ambulating independently 6 months postoperatively. No rebleeding occurred in the 2 patients. Our experience suggests that patients with MCA occlusion can harbor associated aneurysms related to flow through collateral vessels and can present with hemorrhage. Microsurgical repair of these aneurysms can be performed safely to prevent rebleeding. Copyright © 2017 Elsevier Inc. All rights reserved.

Posttraining transcranial magnetic stimulation of striate cortex disrupts consolidation early in visual skill learning.

PubMed

De Weerd, Peter; Reithler, Joel; van de Ven, Vincent; Been, Marin; Jacobs, Christianne; Sack, Alexander T

2012-02-08

Practice-induced improvements in skilled performance reflect "offline " consolidation processes extending beyond daily training sessions. According to visual learning theories, an early, fast learning phase driven by high-level areas is followed by a late, asymptotic learning phase driven by low-level, retinotopic areas when higher resolution is required. Thus, low-level areas would not contribute to learning and offline consolidation until late learning. Recent studies have challenged this notion, demonstrating modified responses to trained stimuli in primary visual cortex (V1) and offline activity after very limited training. However, the behavioral relevance of modified V1 activity for offline consolidation of visual skill memory in V1 after early training sessions remains unclear. Here, we used neuronavigated transcranial magnetic stimulation (TMS) directed to a trained retinotopic V1 location to test for behaviorally relevant consolidation in human low-level visual cortex. Applying TMS to the trained V1 location within 45 min of the first or second training session strongly interfered with learning, as measured by impaired performance the next day. The interference was conditional on task context and occurred only when training in the location targeted by TMS was followed by training in a second location before TMS. In this condition, high-level areas may become coupled to the second location and uncoupled from the previously trained low-level representation, thereby rendering consolidation vulnerable to interference. Our data show that, during the earliest phases of skill learning in the lowest-level visual areas, a behaviorally relevant form of consolidation exists of which the robustness is controlled by high-level, contextual factors.

Whole-brain spectroscopic MRI biomarkers identify infiltrating margins in glioblastoma patients

PubMed Central

Cordova, James S.; Shu, Hui-Kuo G.; Liang, Zhongxing; Gurbani, Saumya S.; Cooper, Lee A. D.; Holder, Chad A.; Olson, Jeffrey J.; Kairdolf, Brad; Schreibmann, Eduard; Neill, Stewart G.; Hadjipanayis, Constantinos G.; Shim, Hyunsuk

2016-01-01

Background The standard of care for glioblastoma (GBM) is maximal safe resection followed by radiation therapy with chemotherapy. Currently, contrast-enhanced MRI is used to define primary treatment volumes for surgery and radiation therapy. However, enhancement does not identify the tumor entirely, resulting in limited local control. Proton spectroscopic MRI (sMRI), a method reporting endogenous metabolism, may better define the tumor margin. Here, we develop a whole-brain sMRI pipeline and validate sMRI metrics with quantitative measures of tumor infiltration. Methods Whole-brain sMRI metabolite maps were coregistered with surgical planning MRI and imported into a neuronavigation system to guide tissue sampling in GBM patients receiving 5-aminolevulinic acid fluorescence-guided surgery. Samples were collected from regions with metabolic abnormalities in a biopsy-like fashion before bulk resection. Tissue fluorescence was measured ex vivo using a hand-held spectrometer. Tissue samples were immunostained for Sox2 and analyzed to quantify the density of staining cells using a novel digital pathology image analysis tool. Correlations among sMRI markers, Sox2 density, and ex vivo fluorescence were evaluated. Results Spectroscopic MRI biomarkers exhibit significant correlations with Sox2-positive cell density and ex vivo fluorescence. The choline to N-acetylaspartate ratio showed significant associations with each quantitative marker (Pearson's ρ = 0.82, P < .001 and ρ = 0.36, P < .0001, respectively). Clinically, sMRI metabolic abnormalities predated contrast enhancement at sites of tumor recurrence and exhibited an inverse relationship with progression-free survival. Conclusions As it identifies tumor infiltration and regions at high risk for recurrence, sMRI could complement conventional MRI to improve local control in GBM patients. PMID:26984746

The relationship between Cho/NAA and glioma metabolism: implementation for margin delineation of cerebral gliomas.

PubMed

Guo, Jun; Yao, Chengjun; Chen, Hong; Zhuang, Dongxiao; Tang, Weijun; Ren, Guang; Wang, Yin; Wu, Jinsong; Huang, Fengping; Zhou, Liangfu

2012-08-01

The marginal delineation of gliomas cannot be defined by conventional imaging due to their infiltrative growth pattern. Here we investigate the relationship between changes in glioma metabolism by proton magnetic resonance spectroscopic imaging ((1)H-MRSI) and histopathological findings in order to determine an optimal threshold value of choline/N-acetyl-aspartate (Cho/NAA) that can be used to define the extent of glioma spread. Eighteen patients with different grades of glioma were examined using (1)H-MRSI. Needle biopsies were performed under the guidance of neuronavigation prior to craniotomy. Intraoperative magnetic resonance imaging (MRI) was performed to evaluate the accuracy of sampling. Haematoxylin and eosin, and immunohistochemical staining with IDH1, MIB-1, p53, CD34 and glial fibrillary acidic protein (GFAP) antibodies were performed on all samples. Logistic regression analysis was used to determine the relationship between Cho/NAA and MIB-1, p53, CD34, and the degree of tumour infiltration. The clinical threshold ratio distinguishing tumour tissue in high-grade (grades III and IV) glioma (HGG) and low-grade (grade II) glioma (LGG) was calculated. In HGG, higher Cho/NAA ratios were associated with a greater probability of higher MIB-1 counts, stronger CD34 expression, and tumour infiltration. Ratio threshold values of 0.5, 1.0, 1.5 and 2.0 appeared to predict the specimens containing the tumour with respective probabilities of 0.38, 0.60, 0.79, 0.90 in HGG and 0.16, 0.39, 0.67, 0.87 in LGG. HGG and LGG exhibit different spectroscopic patterns. Using (1)H-MRSI to guide the extent of resection has the potential to improve the clinical outcome of glioma surgery.

Non-invasive intraoperative optical coherence tomography of the resection cavity during surgery of intrinsic brain tumors

NASA Astrophysics Data System (ADS)

Giese, A.; Böhringer, H. J.; Leppert, J.; Kantelhardt, S. R.; Lankenau, E.; Koch, P.; Birngruber, R.; Hüttmann, G.

2006-02-01

Optical coherence tomography (OCT) is a non-invasive imaging technique with a micrometer resolution. It allows non-contact / non-invasive analysis of central nervous system tissues with a penetration depth of 1-3,5 mm reaching a spatial resolution of approximately 4-15 μm. We have adapted spectral-domain OCT (SD-OCT) and time-domain OCT (TD-OCT) for intraoperative detection of residual tumor during brain tumor surgery. Human brain tumor tissue and areas of the resection cavity were analyzed during the resection of gliomas using this new technology. The site of analysis was registered using a neuronavigation system and biopsies were taken and submitted to routine histology. We have used post image acquisition processing to compensate for movements of the brain and to realign A-scan images for calculation of a light attenuation factor. OCT imaging of normal cortex and white matter showed a typical light attenuation profile. Tumor tissue depending on the cellularity of the specimen showed a loss of the normal light attenuation profile resulting in altered light attenuation coefficients compared to normal brain. Based on this parameter and the microstructure of the tumor tissue, which was entirely absent in normal tissue, OCT analysis allowed the discrimination of normal brain tissue, invaded brain, solid tumor tissue, and necrosis. Following macroscopically complete resections OCT analysis of the resection cavity displayed the typical microstructure and light attenuation profile of tumor tissue in some specimens, which in routine histology contained microscopic residual tumor tissue. We have demonstrated that this technology may be applied to the intraoperative detection of residual tumor during resection of human gliomas.

Conscious brain-to-brain communication in humans using non-invasive technologies.

PubMed

Grau, Carles; Ginhoux, Romuald; Riera, Alejandro; Nguyen, Thanh Lam; Chauvat, Hubert; Berg, Michel; Amengual, Julià L; Pascual-Leone, Alvaro; Ruffini, Giulio

2014-01-01

Human sensory and motor systems provide the natural means for the exchange of information between individuals, and, hence, the basis for human civilization. The recent development of brain-computer interfaces (BCI) has provided an important element for the creation of brain-to-brain communication systems, and precise brain stimulation techniques are now available for the realization of non-invasive computer-brain interfaces (CBI). These technologies, BCI and CBI, can be combined to realize the vision of non-invasive, computer-mediated brain-to-brain (B2B) communication between subjects (hyperinteraction). Here we demonstrate the conscious transmission of information between human brains through the intact scalp and without intervention of motor or peripheral sensory systems. Pseudo-random binary streams encoding words were transmitted between the minds of emitter and receiver subjects separated by great distances, representing the realization of the first human brain-to-brain interface. In a series of experiments, we established internet-mediated B2B communication by combining a BCI based on voluntary motor imagery-controlled electroencephalographic (EEG) changes with a CBI inducing the conscious perception of phosphenes (light flashes) through neuronavigated, robotized transcranial magnetic stimulation (TMS), with special care taken to block sensory (tactile, visual or auditory) cues. Our results provide a critical proof-of-principle demonstration for the development of conscious B2B communication technologies. More fully developed, related implementations will open new research venues in cognitive, social and clinical neuroscience and the scientific study of consciousness. We envision that hyperinteraction technologies will eventually have a profound impact on the social structure of our civilization and raise important ethical issues.

Conscious Brain-to-Brain Communication in Humans Using Non-Invasive Technologies

PubMed Central

Grau, Carles; Ginhoux, Romuald; Riera, Alejandro; Nguyen, Thanh Lam; Chauvat, Hubert; Berg, Michel; Amengual, Julià L.; Pascual-Leone, Alvaro; Ruffini, Giulio

2014-01-01

Human sensory and motor systems provide the natural means for the exchange of information between individuals, and, hence, the basis for human civilization. The recent development of brain-computer interfaces (BCI) has provided an important element for the creation of brain-to-brain communication systems, and precise brain stimulation techniques are now available for the realization of non-invasive computer-brain interfaces (CBI). These technologies, BCI and CBI, can be combined to realize the vision of non-invasive, computer-mediated brain-to-brain (B2B) communication between subjects (hyperinteraction). Here we demonstrate the conscious transmission of information between human brains through the intact scalp and without intervention of motor or peripheral sensory systems. Pseudo-random binary streams encoding words were transmitted between the minds of emitter and receiver subjects separated by great distances, representing the realization of the first human brain-to-brain interface. In a series of experiments, we established internet-mediated B2B communication by combining a BCI based on voluntary motor imagery-controlled electroencephalographic (EEG) changes with a CBI inducing the conscious perception of phosphenes (light flashes) through neuronavigated, robotized transcranial magnetic stimulation (TMS), with special care taken to block sensory (tactile, visual or auditory) cues. Our results provide a critical proof-of-principle demonstration for the development of conscious B2B communication technologies. More fully developed, related implementations will open new research venues in cognitive, social and clinical neuroscience and the scientific study of consciousness. We envision that hyperinteraction technologies will eventually have a profound impact on the social structure of our civilization and raise important ethical issues. PMID:25137064

[First clinical experience with extended planning and navigation in an interventional MRI unit].

PubMed

Moche, M; Schmitgen, A; Schneider, J P; Bublat, M; Schulz, T; Voerkel, C; Trantakis, C; Bennek, J; Kahn, T; Busse, H

2004-07-01

To present an advanced concept for patient-based navigation and to report on our first clinical experience with interventions in the cranium, of soft-tissue structures (breast, liver) and in the musculoskeletal system. A PC-based navigation system was integrated into an existing interventional MRI environment. Intraoperatively acquired 3D data were used for interventional planning. The information content of these reference data was increased by integration of additional image modalities (e. g., fMRI, CT) and by color display of areas with early contrast media enhancement. Within 18 months, the system was used in 123 patients undergoing interventions in different anatomic regions (brain: 64, paranasal sinus: 9, breast: 20, liver: 17, bone: 9, muscle: 4). The mean duration of 64 brain interventions was compared with that of 36 procedures using the scanner's standard navigation. In contrast with the continuous scanning mode of the MR system (0.25 fps), the higher quality as well as the real time display (4 fps) of the MR images reconstructed from the 3D reference data allowed adequate hand-eye coordination. With our system, patient movement and tissue shifts could be immediately detected intraoperatively, and, in contrast to the standard procedure, navigation safely resumed after updating the reference data. The navigation system was characterized by good stability, efficient system integration and easy usability. Despite additional working steps still to be optimized, the duration of the image-guided brain tumor resections was not significantly longer. The presented system combines the advantage of intraoperative MRI with established visualization, planning, and real time capabilities of neuronavigation and can be efficiently applied in a broad range of non-neurosurgical interventions.

[Neurosurgical planning using osirix software].

PubMed

Jaimovich, Sebastián Gastón; Guevara, Martin; Pampin, Sergio; Jaimovich, Roberto; Gardella, Javier Luis

2014-01-01

Anatomical individuality is key to reduce surgical trauma and obtain a better outcome. Nowadays, the advances in neuroimaging has allowed us to analyze this anatomical individuality and to plan the surgery. With this objective, we present our experience with the OsiriX software. We present three different applications as example of forty procedures performed. Case 1: Patient with a premotor cortex convexity parasagittal meningioma; Case 2: Patient with a nonfunctioning pituitary macroadenoma operated on 2 years ago in another institution, achieving a partial resection by a transsphenoidal approach; Case 3: Patient with bilateral middle cerebellar peduncles lesions. OsiriX Software was used for surgical planning. Volumetric CT and MRI images were fused and 3D reconstruction images obtained, to analyze anatomical relationships, measure distances, coordinates and trajectories, among other features. OsiriX software is a useful, open-source and free software tool that provides the surgeon with valuable information. It allows to study individual patient's anatomy and plan a surgical approach in a fast, simple, inexpensive and safety way. In Case 1 the software let us analyze the relationship of the tumor with the surrounding structures in order to minimize the approach's morbidity. In Case 2, to understand the unique anatomic characteristics of an already operated patient giving us important information regarding pathways and need for extra bone removal, achieving a complete tumor resection by an endoscopic transnasal approach. In Case 3, allowed us to obtain the stereotactic coordinates and trajectory for a not visualizable CT scan lesion. When expensive neuronavigation systems are not available, OsiriX is an alternative for neurosurgical planning, with the aim of reducing trauma and surgical morbidity.

Intermittent Theta Burst Stimulation Increases Reward Responsiveness in Individuals with Higher Hedonic Capacity.

PubMed

Duprat, Romain; De Raedt, Rudi; Wu, Guo-Rong; Baeken, Chris

2016-01-01

Repetitive transcranial magnetic stimulation over the left dorsolateral prefrontal cortex (DLPFC) has been documented to influence striatal and orbitofrontal dopaminergic activity implicated in reward processing. However, the exact neuropsychological mechanisms of how DLPFC stimulation may affect the reward system and how trait hedonic capacity may interact with the effects remains to be elucidated. In this sham-controlled study in healthy individuals, we investigated the effects of a single session of neuronavigated intermittent theta burst stimulation (iTBS) on reward responsiveness, as well as the influence of trait hedonic capacity. We used a randomized crossover single session iTBS design with an interval of 1 week. We assessed reward responsiveness using a rewarded probabilistic learning task and measured individual trait hedonic capacity (the ability to experience pleasure) with the temporal experience of pleasure scale questionnaire. As expected, the participants developed a response bias toward the most rewarded stimulus (rich stimulus). Reaction time and accuracy for the rich stimulus were respectively shorter and higher as compared to the less rewarded stimulus (lean stimulus). Active or sham stimulation did not seem to influence the outcome. However, when taking into account individual trait hedonic capacity, we found an early significant increase in the response bias only after active iTBS. The higher the individual's trait hedonic capacity, the more the response bias toward the rich stimulus increased after the active stimulation. When taking into account trait hedonic capacity, one active iTBS session over the left DLPFC improved reward responsiveness in healthy male participants with higher hedonic capacity. This suggests that individual differences in hedonic capacity may influence the effects of iTBS on the reward system.

Supraorbital Keyhole Craniotomy for Basilar Artery Aneurysms: Accounting for the "Cliff" Effect.

PubMed

Stamates, Melissa M; Wong, Andrew K; Bhansali, Anita; Wong, Ricky H

2017-04-01

Treatment of basilar artery aneurysms is challenging. While endovascular techniques have dominated, there still remain circumstances where open surgical clipping is required or preferred. Minimally invasive "keyhole" approaches are being used more frequently to provide the durability of surgical clipping with a lower morbidity profile; however, careful patient selection is required. The supraorbital "keyhole" approach has been described for the treatment of basilar artery aneurysms, but careful assessment of the basilar exposure is necessary to ensure proper visualization of the aneurysm and ability to obtain proximal vascular control. Various methods of estimating the basilar artery exposure in this approach have been described, including the anterior skull base line and the posterior clinoid line, but both are unreliable and inaccurate. To propose a new method, the orbital roof-dorsum line, to simply and accurately predict the basilar artery exposure. CT angiograms for 20 consecutive unique patients were analyzed to obtain the anterior skull base line, posterior clinoid line, and the orbital roof-dorsum line. CT angiograms were then loaded onto a Stealth neuronavigation system (Medtronic, Minneapolis, Minnesota) to obtain "true" visualization lengths. A case illustration is presented. Pairwise comparison tests demonstrated that both the anterior skull base and the posterior clinoid estimation lines differed significantly from the "true"  value ( P < .0001). Our orbital roof-dorsum estimation provided results that accurately predicted the "true" value ( P = .71). The orbital roof-dorsum line provides a simple and reliable method of estimating basilar artery exposure and should be used whenever considering patients for surgical clipping by this approach. Copyright © 2017 by the Congress of Neurological Surgeons

A Low-Cost iPhone-Assisted Augmented Reality Solution for the Localization of Intracranial Lesions

PubMed Central

Zhu, RuYuan; Chen, XiaoLei; Zhang, Jun

2016-01-01

Background Precise location of intracranial lesions before surgery is important, but occasionally difficult. Modern navigation systems are very helpful, but expensive. A low-cost solution that could locate brain lesions and their surface projections in augmented reality would be beneficial. We used an iPhone to partially achieve this goal, and evaluated its accuracy and feasibility in a clinical neurosurgery setting. Methodology/Principal Findings We located brain lesions in 35 patients, and using an iPhone, we depicted the lesion’s surface projection onto the skin of the head. To assess the accuracy of this method, we pasted computed tomography (CT) markers surrounding the depicted lesion boundaries on the skin onto 15 patients. CT scans were then performed with or without contrast enhancement. The deviations (D) between the CT markers and the actual lesion boundaries were measured. We found that 97.7% of the markers displayed a high accuracy level (D ≤ 5mm). In the remaining 20 patients, we compared our iPhone-based method with a frameless neuronavigation system. Four check points were chosen on the skin surrounding the depicted lesion boundaries, to assess the deviations between the two methods. The integrated offset was calculated according to the deviations at the four check points. We found that for the supratentorial lesions, the medial offset between these two methods was 2.90 mm and the maximum offset was 4.2 mm. Conclusions/Significance This low-cost, image-based, iPhone-assisted, augmented reality solution is technically feasible, and helpful for the localization of some intracranial lesions, especially shallow supratentorial intracranial lesions of moderate size. PMID:27454518

Navigation and Image Injection for Control of Bone Removal and Osteotomy Planes in Spine Surgery.

PubMed

Kosterhon, Michael; Gutenberg, Angelika; Kantelhardt, Sven Rainer; Archavlis, Elefterios; Giese, Alf

2017-04-01

In contrast to cranial interventions, neuronavigation in spinal surgery is used in few applications, not tapping into its full technological potential. We have developed a method to preoperatively create virtual resection planes and volumes for spinal osteotomies and export 3-D operation plans to a navigation system controlling intraoperative visualization using a surgical microscope's head-up display. The method was developed using a Sawbone ® model of the lumbar spine, demonstrating feasibility with high precision. Computer tomographic and magnetic resonance image data were imported into Amira ® , a 3-D visualization software. Resection planes were positioned, and resection volumes representing intraoperative bone removal were defined. Fused to the original Digital Imaging and Communications in Medicine data, the osteotomy planes were exported to the cranial version of a Brainlab ® navigation system. A navigated surgical microscope with video connection to the navigation system allowed intraoperative image injection to visualize the preplanned resection planes. The workflow was applied to a patient presenting with a congenital hemivertebra of the thoracolumbar spine. Dorsal instrumentation with pedicle screws and rods was followed by resection of the deformed vertebra guided by the in-view image injection of the preplanned resection planes into the optical path of a surgical microscope. Postoperatively, the patient showed no neurological deficits, and the spine was found to be restored in near physiological posture. The intraoperative visualization of resection planes in a microscope's head-up display was found to assist the surgeon during the resection of a complex-shaped bone wedge and may help to further increase accuracy and patient safety. Copyright © 2017 by the Congress of Neurological Surgeons

Intraoperative Magnetic Resonance Imaging of Cerebral Oxygen Metabolism During Resection of Brain Lesions.

PubMed

Stadlbauer, Andreas; Merkel, Andreas; Zimmermann, Max; Sommer, Björn; Buchfelder, Michael; Meyer-Bäse, Anke; Rössler, Karl

2017-04-01

Tissue oxygen tension is an important parameter for brain tissue viability and its noninvasive intraoperative monitoring in the whole brain is of highly clinical relevance. The purpose of this study was the introduction of a multiparametric quantitative blood oxygenation dependent magnetic resonance imaging (MRI) approach for intraoperative examination of oxygen metabolism during the resection of brain lesions. Sixteen patients suffering from brain lesions were examined intraoperatively twice (before craniotomy and after gross-total resection) via the quantitative blood oxygenation dependent technique and a 1.5-Tesla MRI scanner, which is installed in an operating room. The MRI protocol included T2*- and T2 mapping and dynamic susceptibility weighted perfusion. Data analysis was performed with a custom-made, in-house MatLab software for calculation of maps of oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO 2 ) as well as of cerebral blood volume and cerebral blood flow. Perilesional edema showed a significant increase in both perfusion (cerebral blood volume +21%, cerebral blood flow +13%) and oxygen metabolism (OEF +32%, CMRO 2  +16%) after resection of the lesions. In perilesional nonedematous tissue only, however, oxygen metabolism (OEF +19%, CMRO 2  +11%) was significantly increased, but not perfusion. No changes were found in normal brain. Fortunately, no neurovascular adverse events were observed. This approach for intraoperative examination of oxygen metabolism in the whole brain is a new application of intraoperative MRI additionally to resection control (residual tumor detection) and updating of neuronavigation (brain shift detection). It may help to detect neurovascular adverse events early during surgery. Copyright © 2017 Elsevier Inc. All rights reserved.

Localization of cortical primary motor area of the hand using navigated transcranial magnetic stimulation, BOLD and arterial spin labeling fMRI.

PubMed

Kallioniemi, Elisa; Pitkänen, Minna; Könönen, Mervi; Vanninen, Ritva; Julkunen, Petro

2016-11-01

Although the relationship between neuronavigated transcranial magnetic stimulation (nTMS) and functional magnetic resonance imaging (fMRI) has been widely studied in motor mapping, it is unknown how the motor response type or the choice of motor task affect this relationship. Centers of gravity (CoGs) and response maxima were measured with blood-oxygen-level dependent (BOLD) and arterial spin labeling (ASL) fMRI during motor tasks against nTMS CoGs and response maxima, which were mapped with motor evoked potentials (MEPs) and silent periods (SPs). No differences in motor representations (CoGs and response maxima) were observed in lateral-medial direction (p=0.265). fMRI methods localized the motor representation more posterior than nTMS (p<0.001). This was not affected by the BOLD fMRI motor task (p>0.999) nor nTMS response type (p>0.999). ASL fMRI maxima did not differ from the nTMS nor BOLD fMRI CoGs (p≥0.070), but the ASL CoG was deeper in comparison to other methods (p≤0.042). The BOLD fMRI motor task did not influence the depth of the motor representation (p≥0.745). The median Euclidean distances between the nTMS and fMRI motor representations varied between 7.7mm and 14.5mm and did not differ between the methods (F≤1.23, p≥0.318). The relationship between fMRI and nTMS mapped excitatory (MEP) and inhibitory (SP) responses, and whether the choice of motor task affects this relationship, have not been studied before. The congruence between fMRI and nTMS is good. The choice of nTMS motor response type nor BOLD fMRI motor task had no effect on this relationship. Copyright © 2016 Elsevier B.V. All rights reserved.

Early Re-Do Surgery for Glioblastoma Is a Feasible and Safe Strategy to Achieve Complete Resection of Enhancing Tumor

PubMed Central

Schucht, Philippe; Murek, Michael; Jilch, Astrid; Seidel, Kathleen; Hewer, Ekkehard; Wiest, Roland; Raabe, Andreas; Beck, Jürgen

2013-01-01

Background Complete resection of enhancing tumor as assessed by early (<72 hours) postoperative MRI is regarded as the optimal result in glioblastoma surgery. As yet, there is no consensus on standard procedure if post-operative imaging reveals unintended tumor remnants. Objective The current study evaluated the feasibility and safety of an early re-do surgery aimed at completing resections with the aid of 5-ALA fluorescence and neuronavigation after detection of enhancing tumor remnants on post-operative MRI. Methods From October 2008 to October 2012 a single center institutional protocol offered a second surgery within one week to patients with unintentional incomplete glioblastoma resection. We report on the feasibility of the use 5-ALA fluorescence guidance, the extent of resection (EOR) rates and complications of early re-do surgery. Results Nine of 151 patients (6%) with glioblastoma resections had an unintentional tumor remnant with a volume >0.175 cm3. 5-ALA guided re-do surgery completed the resection (CRET) in all patients without causing neurological deficits, infections or other complications. Patients who underwent a re-do surgery remained hospitalized between surgeries, resulting in a mean length of hospital stay of 11 days (range 7-15), compared to 9 days for single surgery (range 3-23; p=0.147). Conclusion Our early re-do protocol led to complete resection of all enhancing tumor in all cases without any new neurological deficits and thus provides a similar oncological result as intraoperative MRI (iMRI). The repeated use of 5-ALA induced fluorescence, used for identification of small remnants, remains highly sensitive and specific in the setting of re-do surgery. Early re-do surgery is a feasible and safe strategy to complete unintended subtotal resections. PMID:24348904

Retractor-induced brain shift compensation in image-guided neurosurgery

NASA Astrophysics Data System (ADS)

Fan, Xiaoyao; Ji, Songbai; Hartov, Alex; Roberts, David; Paulsen, Keith

2013-03-01

In image-guided neurosurgery, intraoperative brain shift significantly degrades the accuracy of neuronavigation that is solely based on preoperative magnetic resonance images (pMR). To compensate for brain deformation and to maintain the accuracy in image guidance achieved at the start of surgery, biomechanical models have been developed to simulate brain deformation and to produce model-updated MR images (uMR) to compensate for brain shift. To-date, most studies have focused on shift compensation at early stages of surgery (i.e., updated images are only produced after craniotomy and durotomy). Simulating surgical events at later stages such as retraction and tissue resection are, perhaps, clinically more relevant because of the typically much larger magnitudes of brain deformation. However, these surgical events are substantially more complex in nature, thereby posing significant challenges in model-based brain shift compensation strategies. In this study, we present results from an initial investigation to simulate retractor-induced brain deformation through a biomechanical finite element (FE) model where whole-brain deformation assimilated from intraoperative data was used produce uMR for improved accuracy in image guidance. Specifically, intensity-encoded 3D surface profiles at the exposed cortical area were reconstructed from intraoperative stereovision (iSV) images before and after tissue retraction. Retractor-induced surface displacements were then derived by coregistering the surfaces and served as sparse displacement data to drive the FE model. With one patient case, we show that our technique is able to produce uMR that agrees well with the reconstructed iSV surface after retraction. The computational cost to simulate retractor-induced brain deformation was approximately 10 min. In addition, our approach introduces minimal interruption to the surgical workflow, suggesting the potential for its clinical application.

Effects of a common transcranial direct current stimulation (tDCS) protocol on motor evoked potentials found to be highly variable within individuals over 9 testing sessions.

PubMed

Horvath, Jared Cooney; Vogrin, Simon J; Carter, Olivia; Cook, Mark J; Forte, Jason D

2016-09-01

Transcranial direct current stimulation (tDCS) uses a weak electric current to modulate neuronal activity. A neurophysiologic outcome measure to demonstrate reliable tDCS modulation at the group level is transcranial magnetic stimulation engendered motor evoked potentials (MEPs). Here, we conduct a study testing the reliability of individual MEP response patterns following a common tDCS protocol. Fourteen participants (7m/7f) each underwent nine randomized sessions of 1 mA, 10 min tDCS (3 anode; 3 cathode; 3 sham) delivered using an M1/orbito-frontal electrode montage (sessions separated by an average of ~5.5 days). Fifteen MEPs were obtained prior to, immediately following and in 5 min intervals for 30 min following tDCS. TMS was delivered at 130 % resting motor threshold using neuronavigation to ensure consistent coil localization. A number of non-experimental variables were collected during each session. At the individual level, considerable variability was seen among different testing sessions. No participant demonstrated an excitatory response ≥20 % to all three anodal sessions, and no participant demonstrated an inhibitory response ≥20 % to all three cathodal sessions. Intra-class correlation revealed poor anodal and cathodal test-retest reliability [anode: ICC(2,1) = 0.062; cathode: ICC(2,1) = 0.055] and moderate sham test-retest reliability [ICC(2,1) = 0.433]. Results also revealed no significant effect of tDCS at the group level. Using this common protocol, we found the effects of tDCS on MEP amplitudes to be highly variable at the individual level. In addition, no significant effects of tDCS on MEP amplitude were found at the group level. Future studies should consider utilizing a more strict experimental protocol to potentially account for intra-individual response variations.

Modeling transcranial magnetic stimulation from the induced electric fields to the membrane potentials along tractography-based white matter fiber tracts

NASA Astrophysics Data System (ADS)

De Geeter, Nele; Dupré, Luc; Crevecoeur, Guillaume

2016-04-01

Objective. Transcranial magnetic stimulation (TMS) is a promising non-invasive tool for modulating the brain activity. Despite the widespread therapeutic and diagnostic use of TMS in neurology and psychiatry, its observed response remains hard to predict, limiting its further development and applications. Although the stimulation intensity is always maximum at the cortical surface near the coil, experiments reveal that TMS can affect deeper brain regions as well. Approach. The explanation of this spread might be found in the white matter fiber tracts, connecting cortical and subcortical structures. When applying an electric field on neurons, their membrane potential is altered. If this change is significant, more likely near the TMS coil, action potentials might be initiated and propagated along the fiber tracts towards deeper regions. In order to understand and apply TMS more effectively, it is important to capture and account for this interaction as accurately as possible. Therefore, we compute, next to the induced electric fields in the brain, the spatial distribution of the membrane potentials along the fiber tracts and its temporal dynamics. Main results. This paper introduces a computational TMS model in which electromagnetism and neurophysiology are combined. Realistic geometry and tissue anisotropy are included using magnetic resonance imaging and targeted white matter fiber tracts are traced using tractography based on diffusion tensor imaging. The position and orientation of the coil can directly be retrieved from the neuronavigation system. Incorporating these features warrants both patient- and case-specific results. Significance. The presented model gives insight in the activity propagation through the brain and can therefore explain the observed clinical responses to TMS and their inter- and/or intra-subject variability. We aspire to advance towards an accurate, flexible and personalized TMS model that helps to understand stimulation in the connected

Advances in diagnosis and treatment of trigeminal neuralgia

PubMed Central

Montano, Nicola; Conforti, Giulio; Di Bonaventura, Rina; Meglio, Mario; Fernandez, Eduardo; Papacci, Fabio

2015-01-01

Various drugs and surgical procedures have been utilized for the treatment of trigeminal neuralgia (TN). Despite numerous available approaches, the results are not completely satisfying. The need for more contemporaneous drugs to control the pain attacks is a common experience. Moreover, a number of patients become drug resistant, needing a surgical procedure to treat the neuralgia. Nonetheless, pain recurrence after one or more surgical operations is also frequently seen. These facts reflect the lack of the precise understanding of the TN pathogenesis. Classically, it has been related to a neurovascular compression at the trigeminal nerve root entry-zone in the prepontine cistern. However, it has been evidenced that in the pain onset and recurrence, various neurophysiological mechanisms other than the neurovascular conflict are involved. Recently, the introduction of new magnetic resonance techniques, such as voxel-based morphometry, diffusion tensor imaging, three-dimensional time-of-flight magnetic resonance angiography, and fluid attenuated inversion recovery sequences, has provided new insight about the TN pathogenesis. Some of these new sequences have also been used to better preoperatively evidence the neurovascular conflict in the surgical planning of microvascular decompression. Moreover, the endoscopy (during microvascular decompression) and the intraoperative computed tomography with integrated neuronavigation (during percutaneous procedures) have been recently introduced in the challenging cases. In the last few years, efforts have been made in order to better define the optimal target when performing the gamma knife radiosurgery. Moreover, some authors have also evidenced that neurostimulation might represent an opportunity in TN refractory to other surgical treatments. The aim of this work was to review the recent literature about the pathogenesis, diagnosis, and medical and surgical treatments, and discuss the significant advances in all these fields

Anterior superior alveolar nerve injury after extended endoscopic medial maxillectomy: a preclinical study to predict neurological morbidity.

PubMed

Schreiber, Alberto; Mattavelli, Davide; Ferrari, Marco; Rampinelli, Vittorio; Lancini, Davide; Ravanelli, Marco; Bertazzoni, Giacomo; Rodella, Luigi Fabrizio; Buffoli, Barbara; Doglietto, Francesco; Nicolai, Piero

2017-10-01

Endoscopic medial maxillectomies (EMMs) are used to optimize exposure of the maxillary sinus and retromaxillary areas. Although in type D EMM (Sturmann-Canfield procedure) the anterior superior alveolar nerve (ASAN) is always at risk of injury, only 29% of patients complained of alveolar process and dental anesthesia. The purpose of this anatomical study is to assess the neural anastomotic network of the ASAN (ASAN-NAN) and describe different extensions of type D EMMs in a preclinical setting. The ASAN and its medial anastomotic branches (MABs) and lateral anastomotic branches (LABs) were evaluated by cone-beam computerized tomography (CBCT). Five different extensions of type D (D1 to D5) EMMs were identified and nerves at risk of injury in each type were assessed by CBCT. Moreover, quantification of surgical corridors was performed on cadaver heads with a neuronavigation system. Fifty-seven CBCT scans were analyzed. The ASAN would be spared in 16.3% of cases with a type D1 EMM, while it would be injured in the majority of type D2 to D5 resections. At least 1 nerve of the ASAN-NAN was spared in 96.6%, 93%, 74.6%, 0%, and 65.8% of type D1 to D5 EMMs, respectively. Two cadaver heads were dissected and the incremental volume and number of maxillary subsites exposed was assessed in type D1 to D5 EMMs. ASAN function impairment is probably compensated by LABs and MABs. If this hypothesis will be validated in a prospective study on patients, preoperative CBCT evaluation could predict neurological morbidity after type D EMM, and allow tailoring the procedure to minimize impairment of the ASAN-NAN. © 2017 ARS-AAOA, LLC.

Versatile utilization of real-time intraoperative contrast-enhanced ultrasound in cranial neurosurgery: technical note and retrospective case series.

PubMed

Lekht, Ilya; Brauner, Noah; Bakhsheshian, Joshua; Chang, Ki-Eun; Gulati, Mittul; Shiroishi, Mark S; Grant, Edward G; Christian, Eisha; Zada, Gabriel

2016-03-01

Intraoperative contrast-enhanced ultrasound (iCEUS) offers dynamic imaging and provides functional data in real time. However, no standardized protocols or validated quantitative data exist to guide its routine use in neurosurgery. The authors aimed to provide further clinical data on the versatile application of iCEUS through a technical note and illustrative case series. Five patients undergoing craniotomies for suspected tumors were included. iCEUS was performed using a contrast agent composed of lipid shell microspheres enclosing perflutren (octafluoropropane) gas. Perfusion data were acquired through a time-intensity curve analysis protocol obtained using iCEUS prior to biopsy and/or resection of all lesions. Three primary tumors (gemistocytic astrocytoma, glioblastoma multiforme, and meningioma), 1 metastatic lesion (melanoma), and 1 tumefactive demyelinating lesion (multiple sclerosis) were assessed using real-time iCEUS. No intraoperative complications occurred following multiple administrations of contrast agent in all cases. In all neoplastic cases, iCEUS replicated enhancement patterns observed on preoperative Gd-enhanced MRI, facilitated safe tumor debulking by differentiating neoplastic tissue from normal brain parenchyma, and helped identify arterial feeders and draining veins in and around the surgical cavity. Intraoperative CEUS was also useful in guiding a successful intraoperative needle biopsy of a cerebellar tumefactive demyelinating lesion obtained during real-time perfusion analysis. Intraoperative CEUS has potential for safe, real-time, dynamic contrast-based imaging for routine use in neurooncological surgery and image-guided biopsy. Intraoperative CEUS eliminates the effect of anatomical distortions associated with standard neuronavigation and provides quantitative perfusion data in real time, which may hold major implications for intraoperative diagnosis, tissue differentiation, and quantification of extent of resection. Further

Brain-derived neurotrophic factor--a major player in stimulation-induced homeostatic metaplasticity of human motor cortex?

PubMed

Mastroeni, Claudia; Bergmann, Til Ole; Rizzo, Vincenzo; Ritter, Christoph; Klein, Christine; Pohlmann, Ines; Brueggemann, Norbert; Quartarone, Angelo; Siebner, Hartwig Roman

2013-01-01

Repetitive transcranial magnetic stimulation (rTMS) of the human motor hand area (M1HAND) can induce lasting changes in corticospinal excitability as indexed by a change in amplitude of the motor-evoked potential. The plasticity-inducing effects of rTMS in M1HAND show substantial inter-individual variability which has been partially attributed to the val(66)met polymorphism in the brain-derived neurotrophic factor (BDNF) gene. Here we used theta burst stimulation (TBS) to examine whether the BDNF val(66)met genotype can be used to predict the expression of TBS-induced homeostatic metaplasticity in human M1HAND. TBS is a patterned rTMS protocol with intermittent TBS (iTBS) usually inducing a lasting increase and continuous TBS (cTBS) a lasting decrease in corticospinal excitability. In three separate sessions, healthy val(66)met (n = 12) and val(66)val (n = 17) carriers received neuronavigated cTBS followed by cTBS (n = 27), cTBS followed by iTBS (n = 29), and iTBS followed by iTBS (n = 28). Participants and examiner were blinded to the genotype at the time of examination. As expected, the first TBS intervention induced a decrease (cTBS) and increase (iTBS) in corticospinal excitability, respectively, at the same time priming the after effects caused by the second TBS intervention in a homeostatic fashion. Critically, val(66)met carriers and val(66)val carriers showed very similar response patterns to cTBS and iTBS regardless of the order of TBS interventions. Since none of the observed TBS effects was modulated by the BDNF val(66)met polymorphism, our results do not support the notion that the BDNF val(66)met genotype is a major player with regard to TBS-induced plasticity and metaplasticity in the human M1HAND.

Brain-Derived Neurotrophic Factor – A Major Player in Stimulation-Induced Homeostatic Metaplasticity of Human Motor Cortex?

PubMed Central

Rizzo, Vincenzo; Ritter, Christoph; Klein, Christine; Pohlmann, Ines; Brueggemann, Norbert; Quartarone, Angelo; Siebner, Hartwig Roman

2013-01-01

Repetitive transcranial magnetic stimulation (rTMS) of the human motor hand area (M1HAND) can induce lasting changes in corticospinal excitability as indexed by a change in amplitude of the motor-evoked potential. The plasticity-inducing effects of rTMS in M1HAND show substantial inter-individual variability which has been partially attributed to the val66met polymorphism in the brain-derived neurotrophic factor (BDNF) gene. Here we used theta burst stimulation (TBS) to examine whether the BDNF val66met genotype can be used to predict the expression of TBS-induced homeostatic metaplasticity in human M1HAND. TBS is a patterned rTMS protocol with intermittent TBS (iTBS) usually inducing a lasting increase and continuous TBS (cTBS) a lasting decrease in corticospinal excitability. In three separate sessions, healthy val66met (n = 12) and val66val (n = 17) carriers received neuronavigated cTBS followed by cTBS (n = 27), cTBS followed by iTBS (n = 29), and iTBS followed by iTBS (n = 28). Participants and examiner were blinded to the genotype at the time of examination. As expected, the first TBS intervention induced a decrease (cTBS) and increase (iTBS) in corticospinal excitability, respectively, at the same time priming the after effects caused by the second TBS intervention in a homeostatic fashion. Critically, val66met carriers and val66val carriers showed very similar response patterns to cTBS and iTBS regardless of the order of TBS interventions. Since none of the observed TBS effects was modulated by the BDNF val66met polymorphism, our results do not support the notion that the BDNF val66met genotype is a major player with regard to TBS-induced plasticity and metaplasticity in the human M1HAND. PMID:23469118

Presurgical functional magnetic resonance imaging in patients with brain tumors.

PubMed

Ravn, Søren; Holmberg, Mats; Sørensen, Preben; Frokjaer, Jens B; Carl, Jesper

2016-01-01

Clinical functional magnetic resonance imaging (fMRI) is still an upcoming diagnostic tool because it is time-consuming to perform the post-scan calculations and interpretations. A standardized and easily used method for the clinical assessment of fMRI scans could decrease the workload and make fMRI more attractive for clinical use. To evaluate a standardized clinical approach for distance measurement between benign brain tumors and eloquent cortex in terms of the ability to predict pre- and postoperative neurological deficits after intraoperative neuronavigation-assisted surgery. A retrospective study of 34 patients. The fMRI data were reanalyzed using a standardized distance measurement procedure combining data from both fMRI and three-dimensional T1 MRI scans. The pre- and postoperative neurological status of each patient was obtained from hospital records. Data analysis was performed using logistic regression analysis to determine whether the distance measured between the tumor margin and fMRI activity could serve as a predictor for neurological deficits. An odds ratio of 0.89 mm(-1) (P = 0.03) was found between the risk of preoperative neurological motor deficits and the tumor-fMRI distance. An odds ratio of 0.82 mm(-1) (P = 0.04) was found between the risk of additional postoperative neurological motor deficits and the tumor-fMRI distance. The tumor was radically removed in 10 cases; five patients experienced additional postoperative motor deficits (tumor-fMRI distance <18 mm) and five did not (tumor-fMRI distance >18 mm) (P = 0.008). This study indicates that the distance measured between the tumor margin and fMRI activation could serve as a valuable predictor of neurological motor deficits. © The Foundation Acta Radiologica 2014.

Does an intraneural interface short-term implant for robotic hand control modulate sensorimotor cortical integration? An EEG-TMS co-registration study on a human amputee.

PubMed

Ferreri, F; Ponzo, D; Vollero, L; Guerra, A; Di Pino, G; Petrichella, S; Benvenuto, A; Tombini, M; Rossini, L; Denaro, L; Micera, S; Iannello, G; Guglielmelli, E; Denaro, V; Rossini, P M

2014-01-01

Following limb amputation, central and peripheral nervous system relays partially maintain their functions and can be exploited for interfacing prostheses. The aim of this study is to investigate, for the first time by means of an EEG-TMS co-registration study, whether and how direct bidirectional connection between brain and hand prosthesis impacts on sensorimotor cortical topography. Within an experimental protocol for robotic hand control, a 26 years-old, left-hand amputated male was selected to have implanted four intrafascicular electrodes (tf-LIFEs-4) in the median and ulnar nerves of the stump for 4 weeks. Before tf-LIFE-4s implant (T0) and after the training period, once electrodes have been removed (T1), experimental subject's cortico-cortical excitability, connectivity and plasticity were tested via a neuronavigated EEG-TMS experiment. The statistical analysis clearly demonstrated a significant modulation (with t-test p < 0.0001) of EEG activity between 30 and 100 ms post-stimulus for the stimulation of the right hemisphere. When studying individual latencies in that time range, a global amplitude modulation was found in most of the TMS-evoked potentials; particularly, the GEE analysis showed significant differences between T0 and T1 condition at 30 ms (p < 0.0404), 46 ms (p < 0.0001) and 60 ms (p < 0.007) latencies. Finally, also a clear local decrement in N46 amplitude over C4 was evident. No differences between conditions were observed for the stimulation of the left hemisphere. The results of this study confirm the hypothesis that bidirectional neural interface could redirect cortical areas -deprived of their original input/output functions- toward restorative neuroplasticity. This reorganization strongly involves bi-hemispheric networks and intracortical and transcortical modulation of GABAergic inhibition.

Aggressive resection at the infiltrative margins of glioblastoma facilitated by intraoperative fluorescein guidance.

PubMed

Neira, Justin A; Ung, Timothy H; Sims, Jennifer S; Malone, Hani R; Chow, Daniel S; Samanamud, Jorge L; Zanazzi, George J; Guo, Xiaotao; Bowden, Stephen G; Zhao, Binsheng; Sheth, Sameer A; McKhann, Guy M; Sisti, Michael B; Canoll, Peter; D'Amico, Randy S; Bruce, Jeffrey N

2017-07-01

OBJECTIVE Extent of resection is an important prognostic factor in patients undergoing surgery for glioblastoma (GBM). Recent evidence suggests that intravenously administered fluorescein sodium associates with tumor tissue, facilitating safe maximal resection of GBM. In this study, the authors evaluate the safety and utility of intraoperative fluorescein guidance for the prediction of histopathological alteration both in the contrast-enhancing (CE) regions, where this relationship has been established, and into the non-CE (NCE), diffusely infiltrated margins. METHODS Thirty-two patients received fluorescein sodium (3 mg/kg) intravenously prior to resection. Fluorescence was intraoperatively visualized using a Zeiss Pentero surgical microscope equipped with a YELLOW 560 filter. Stereotactically localized biopsy specimens were acquired from CE and NCE regions based on preoperative MRI in conjunction with neuronavigation. The fluorescence intensity of these specimens was subjectively classified in real time with subsequent quantitative image analysis, histopathological evaluation of localized biopsy specimens, and radiological volumetric assessment of the extent of resection. RESULTS Bright fluorescence was observed in all GBMs and localized to the CE regions and portions of the NCE margins of the tumors, thus serving as a visual guide during resection. Gross-total resection (GTR) was achieved in 84% of the patients with an average resected volume of 95%, and this rate was higher among patients for whom GTR was the surgical goal (GTR achieved in 93.1% of patients, average resected volume of 99.7%). Intraoperative fluorescein staining correlated with histopathological alteration in both CE and NCE regions, with positive predictive values by subjective fluorescence evaluation greater than 96% in NCE regions. CONCLUSIONS Intraoperative administration of fluorescein provides an easily visualized marker for glioma pathology in both CE and NCE regions of GBM. These

Minimally Invasive Transsulcal Resection of Intraventricular and Periventricular Lesions Through a Tubular Retractor System: Multicentric Experience and Results.

PubMed

Eliyas, Javed Khader; Glynn, Ryan; Kulwin, Charles G; Rovin, Richard; Young, Ronald; Alzate, Juan; Pradilla, Gustavo; Shah, Mitesh V; Kassam, Amin; Ciric, Ivan; Bailes, Julian

2016-06-01

Conventional approaches to deep-seated cerebral lesions range from biopsy to transcortical or transcallosal resection. Although the former does not reduce tumor burden, the latter are more invasive and associated with greater potential for irreparable injury to normal brain. Disconnection syndrome, hemiparesis, hemianesthesia, or aphasia is not uncommon after such surgery, especially when lesion is large. By contrast, the transsulcal parafascicular approach uses naturally existing corridors and a tubular retractor to minimize brain injury. A retrospective review of patients undergoing minimally invasive transsulcal parafascicular resection of ventricular and periventricular lesions, across 5 independent centers, was conducted. Twenty patients with lesions located in the lateral ventricle (n = 9), the third ventricle (n = 6) and periventricular region (n = 4) are described in this report. Average age was 64 years (8 male/12 female). The average depth from cortical surface was 4.37 cm. A 13.5-mm-diameter tubular retractor (BrainPath [NICO Corporation, Indianapolis, Indiana, USA]) of differing lengths was used, aided by neuronavigation. Gross total resection was obtained in 17 patients. Pathologies included colloid cyst, subependymoma, glioma, meningioma, central neurocytoma, lymphoma, and metastasis. Three patients experienced transient morbidity: memory loss (2), hemiparesis (1). One patient died 3 months postoperatively as a result of unrelated pulmonary illness. Follow-up ranged from 6 to 27 months (average, 12 months). This technique is safe and effective for the treatment of intraventricular and periventricular lesions. Surgery-related morbidity is minimal and often transient. Lesions are satisfactorily resected and residuum occurs only when the neoplasm involves vital structures. The tubular retractor minimizes trauma to brain incident in the surgeon's path. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Computation of a high-resolution MRI 3D stereotaxic atlas of the sheep brain.

PubMed

Ella, Arsène; Delgadillo, José A; Chemineau, Philippe; Keller, Matthieu

2017-02-15

The sheep model was first used in the fields of animal reproduction and veterinary sciences and then was utilized in fundamental and preclinical studies. For more than a decade, magnetic resonance (MR) studies performed on this model have been increasingly reported, especially in the field of neuroscience. To contribute to MR translational neuroscience research, a brain template and an atlas are necessary. We have recently generated the first complete T1-weighted (T1W) and T2W MR population average images (or templates) of in vivo sheep brains. In this study, we 1) defined a 3D stereotaxic coordinate system for previously established in vivo population average templates; 2) used deformation fields obtained during optimized nonlinear registrations to compute nonlinear tissues or prior probability maps (nlTPMs) of cerebrospinal fluid (CSF), gray matter (GM), and white matter (WM) tissues; 3) delineated 25 external and 28 internal sheep brain structures by segmenting both templates and nlTPMs; and 4) annotated and labeled these structures using an existing histological atlas. We built a quality high-resolution 3D atlas of average in vivo sheep brains linked to a reference stereotaxic space. The atlas and nlTPMs, associated with previously computed T1W and T2W in vivo sheep brain templates and nlTPMs, provide a complete set of imaging space that are able to be imported into other imaging software programs and could be used as standardized tools for neuroimaging studies or other neuroscience methods, such as image registration, image segmentation, identification of brain structures, implementation of recording devices, or neuronavigation. J. Comp. Neurol. 525:676-692, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Individualized treatment of craniovertebral junction malformation guided by intraoperative computed tomography.

PubMed

Li, Lianfeng; Wang, Peng; Chen, LiFeng; Ma, Xiaodong; Bu, Bo; Yu, Xinguang

2012-04-01

This study was designed to report our preliminary experience of intraoperative computed tomography (iCT) using a mobile scanner with integrated neuronavigation system (NNS). The objective of this study was to assess the feasibility and potential utility of iCT with integrated NNS in individualized treatment of craniovertebral junction malformation (CVJM). The surgical management of congenital craniovertebral anomalies is complex due to the relative difficulty in accessing the region, critical relationships of neurovascular structures, and the intricate biomechanical issues involved. We reported our first 19 complex CVJM cases including 11 male and 8 female patients from January, 2009 to June, 2009 (mean age, 33.9 y; age range, 13 to 58 y). A sliding gantry 40-slice CT scanner was installed in a preexisting operating room. Image data was transferred directly from the scanner into the NNS using an automated registration system. We applied this technology to transoral odontoidectomy in 17 patients. Moreover, with the extra help of iCT integrated with NNS, odontoidectomy through posterior midline approach, and transoral atlantal lateral mass resection were, for the first time, performed for treatment of complex CVJM. NNS was found to correlate well with the intraoperative findings, and the recalibration was uneven in all cases with an accuracy of 1.6 mm (1.6: 1.2 to 2.0). All patients were clinically evaluated by Nurick grade criteria, and neurological deficits were monitored after 3 months of surgery. Fifteen patients (79%) were improved by at least 1 Nurick grade, whereas the grade did not change in 4 patients (21%). iCT scanning with integrated NNS was both feasible and beneficial for the surgical management of complex CVJM. In this unusual patient population, the technique seemed to be valuable in negotiating complex anatomy and achieving a safe and predictable decompression.

Improvement of the insertion axis for cochlear implantation with a robot-based system.

PubMed

Torres, Renato; Kazmitcheff, Guillaume; De Seta, Daniele; Ferrary, Evelyne; Sterkers, Olivier; Nguyen, Yann

2017-02-01

It has previously reported that alignment of the insertion axis along the basal turn of the cochlea was depending on surgeon' experience. In this experimental study, we assessed technological assistances, such as navigation or a robot-based system, to improve the insertion axis during cochlear implantation. A preoperative cone beam CT and a mastoidectomy with a posterior tympanotomy were performed on four temporal bones. The optimal insertion axis was defined as the closest axis to the scala tympani centerline avoiding the facial nerve. A neuronavigation system, a robot assistance prototype, and software allowing a semi-automated alignment of the robot were used to align an insertion tool with an optimal insertion axis. Four procedures were performed and repeated three times in each temporal bone: manual, manual navigation-assisted, robot-based navigation-assisted, and robot-based semi-automated. The angle between the optimal and the insertion tool axis was measured in the four procedures. The error was 8.3° ± 2.82° for the manual procedure (n = 24), 8.6° ± 2.83° for the manual navigation-assisted procedure (n = 24), 5.4° ± 3.91° for the robot-based navigation-assisted procedure (n = 24), and 3.4° ± 1.56° for the robot-based semi-automated procedure (n = 12). A higher accuracy was observed with the semi-automated robot-based technique than manual and manual navigation-assisted (p < 0.01). Combination of a navigation system and a manual insertion does not improve the alignment accuracy due to the lack of friendly user interface. On the contrary, a semi-automated robot-based system reduces both the error and the variability of the alignment with a defined optimal axis.

Distinct contribution of the parietal and temporal cortex to hand configuration and contextual judgements about tools.

PubMed

Andres, Michael; Pelgrims, Barbara; Olivier, Etienne

2013-09-01

Neuropsychological studies showed that manipulatory and semantic knowledge can be independently impaired in patients with upper-limb apraxia, leading to different tool use disorders. The present study aimed to dissociate the brain regions involved in judging the hand configuration or the context associated to tool use. We focussed on the left supramarginalis gyrus (SMG) and left middle temporal gyrus (MTG), whose activation, as evidenced by functional magnetic resonance imaging (fMRI) studies, suggests that they may play a critical role in tool use. The distinctive location of SMG in the dorsal visual stream led us to postulate that this parietal region could play a role in processing incoming information about tools to shape hand posture. In contrast, we hypothesized that MTG, because of its interconnections with several cortical areas involved in semantic memory, could contribute to retrieving semantic information necessary to create a contextual representation of tool use. To test these hypotheses, we used neuronavigated transcranial magnetic stimulation (TMS) to interfere transiently with the function of either left SMG or left MTG in healthy participants performing judgement tasks about either hand configuration or context of tool use. We found that SMG virtual lesions impaired hand configuration but not contextual judgements, whereas MTG lesions selectively interfered with judgements about the context of tool use while leaving hand configuration judgements unaffected. This double dissociation demonstrates that the ability to infer a context of use or a hand posture from tool perception relies on distinct processes, performed in the temporal and parietal regions. The present findings suggest that tool use disorders caused by SMG lesions will be characterized by difficulties in selecting the appropriate hand posture for tool use, whereas MTG lesions will yield difficulties in using tools in the appropriate context. Copyright © 2012. Published by Elsevier Ltd.

Acute triventricular hydrocephalus caused by choroid plexus cysts: a diagnostic and neurosurgical challenge.

PubMed

Spennato, Pietro; Chiaramonte, Carmela; Cicala, Domenico; Donofrio, Vittoria; Barbarisi, Manlio; Nastro, Anna; Mirone, Giuseppe; Trischitta, Vincenzo; Cinalli, Giuseppe

2016-11-01

OBJECTIVE Intraventricular choroid plexus cysts are unusual causes of acute hydrocephalus in children. Radiological diagnosis of intraventricular choroid plexus cysts is difficult because they have very thin walls and fluid contents similar to CSF and can go undetected on routine CT studies. METHODS This study reports the authors' experience with 5 patients affected by intraventricular cysts originating from the choroid plexus. All patients experienced acute presentation with rapid neurological deterioration, sometimes associated with hypothalamic dysfunction, and required urgent surgery. In 2 cases the symptoms were intermittent, with spontaneous remission and sudden clinical deteriorations, reflecting an intermittent obstruction of the CSF pathway. RESULTS Radiological diagnosis was difficult in these cases because a nonenhanced CT scan revealed only triventricular hydrocephalus, with slight lateral ventricle asymmetry in all cases. MRI with driven-equilibrium sequences and CT ventriculography (in 1 case) allowed the authors to accurately diagnose the intraventricular cysts that typically occupied the posterior part of the third ventricle, occluding the aqueduct and at least 1 foramen of Monro. The patients were managed by urgent implantation of an external ventricular drain in 1 case (followed by endoscopic surgery, after completing a diagnostic workup) and by urgent endoscopic surgery in 4 cases. Endoscopic surgery allowed the shrinkage and near-complete removal of the cysts in all cases. Use of neuronavigation and a laser were indispensable. All procedures were uneventful, resulting in restoration of normal neurological conditions. Long-term follow-up (> 2 years) was available for 2 patients, and no complications or recurrences occurred. CONCLUSIONS This case series emphasizes the necessity of an accurate and precise identification of the possible causes of triventricular hydrocephalus. Endoscopic surgery can be considered the ideal treatment of choroid plexus

Awake Craniotomy with Noninvasive Brain Mapping by 3-Tesla Functional Magnetic Resonance Imaging for Excision of Low-grade Glioma: A Case of a Young Patient from Pakistan.

PubMed

Aleem Bhatti, Atta Ul; Jakhrani, Nasir Khan; Parekh, Maria Adnan

2018-01-01

The past few years have seen increasing support for gross total resection in the management of low-grade gliomas (LGGs), with a greater extent of resection correlated with better overall survival, progression-free survival, and time to malignant transformation. There is consistent evidence in literature supporting extent of safe resection as a good prognostic indicator as well as positively affecting seizure control, symptomatic relief in pressure symptoms, and longer progression-free and total survival. The operative goal in most LGG cases is to maximize the extent of resection for these benefits while avoiding postoperative neurologic deficits. Several advanced invasive and noninvasive surgical techniques such as intraoperative magnetic resonance imaging (MRI), fluorescence-guided surgery, intraoperative functional pathway mapping, and neuronavigation have been developed in an attempt to better achieve maximal safe resection. We present a case of LGG in a young patient with a 5-year history of refractory seizures and gradual onset walking difficulty. Serial MRI brain scans revealed a progressive increase in right frontal tumor size with substantial edema and parafalcine herniation. Noninvasive brain mapping by functional MRI (fMRI) and sleep-awake-sleep type of anesthesia with endotracheal tube insertion was utilized during an awake craniotomy. Histopathology confirmed a Grade II oligodendroglioma, and genetic analysis revealed no codeletion at 1p/19q. Neurological improvement was remarkable in terms of immediate motor improvement, and the patient remained completely seizure free on a single antiepileptic drug. There is no radiologic or clinical evidence of recurrence 6 months postoperatively. This is the first published report of an awake craniotomy for LGG in Pakistan. The contemporary concept of supratotal resection in LGGs advocates generous functional resection even beyond MRI findings rather than mere excision of oncological boundaries. This relatively

Localizing ECoG electrodes on the cortical anatomy without post-implantation imaging

PubMed Central

Gupta, Disha; Hill, N. Jeremy; Adamo, Matthew A.; Ritaccio, Anthony; Schalk, Gerwin

2014-01-01

Introduction Electrocorticographic (ECoG) grids are placed subdurally on the cortex in people undergoing cortical resection to delineate eloquent cortex. ECoG signals have high spatial and temporal resolution and thus can be valuable for neuroscientific research. The value of these data is highest when they can be related to the cortical anatomy. Existing methods that establish this relationship rely either on post-implantation imaging using computed tomography (CT), magnetic resonance imaging (MRI) or X-Rays, or on intra-operative photographs. For research purposes, it is desirable to localize ECoG electrodes on the brain anatomy even when post-operative imaging is not available or when intra-operative photographs do not readily identify anatomical landmarks. Methods We developed a method to co-register ECoG electrodes to the underlying cortical anatomy using only a pre-operative MRI, a clinical neuronavigation device (such as BrainLab VectorVision), and fiducial markers. To validate our technique, we compared our results to data collected from six subjects who also had post-grid implantation imaging available. We compared the electrode coordinates obtained by our fiducial-based method to those obtained using existing methods, which are based on co-registering pre- and post-grid implantation images. Results Our fiducial-based method agreed with the MRI–CT method to within an average of 8.24 mm (mean, median = 7.10 mm) across 6 subjects in 3 dimensions. It showed an average discrepancy of 2.7 mm when compared to the results of the intra-operative photograph method in a 2D coordinate system. As this method does not require post-operative imaging such as CTs, our technique should prove useful for research in intra-operative single-stage surgery scenarios. To demonstrate the use of our method, we applied our method during real-time mapping of eloquent cortex during a single-stage surgery. The results demonstrated that our method can be applied intra

Image guided surgery in the management of craniocerebral gunshot injuries

PubMed Central

Elserry, Tarek; Anwer, Hesham; Esene, Ignatius Ngene

2013-01-01

Background: A craniocerebral trauma caused by firearms is a complex injury with high morbidity and mortality. One of the most intriguing and controversial part in their management in salvageable patients is the decision to remove the bullet/pellet. A bullet is foreign to the brain and, in principle, should be removed. Surgical options for bullet extraction span from conventional craniotomy, through C-arm-guided surgery to minimally invasive frame or frameless stereotaxy. But what is the best surgical option? Methods: We prospectively followed up a cohort of 28 patients with cranio-cerebral gunshot injury (CCHSI) managed from January to December 2012 in our department of neurosurgery. The missiles were extracted via stereotaxy (frame or frameless), C-arm-guided, or free-hand-based surgery. Cases managed conservatively were excluded. The Glasgow Outcome Score was used to assess the functional outcome on discharge. Results: Five of the eight “stereotactic cases” had an excellent outcome after missile extraction while the initially planned stereotaxy missed locating the missile in three cases and were thus subjected to free hand craniotomy. Excellent outcome was obtained in five of the nine “neuronavigation cases, five of the eight cases for free hand surgery based on the bony landmarks, and five of the six C-arm-based surgery. Conclusion: Conventional craniotomy isn’t indicated in the extraction of isolated, retained, intracranial firearm missiles in civilian injury but could be useful when the missile is incorporated within a surgical lesion. Stereotactic surgery could be useful for bullet extraction, though with limited precision in identifying small pellets because of their small sizes, thus exposing patients to same risk of brain insult when retrieving a missile by conventional surgery. Because of its availability, C-arm-guided surgery continues to be of much benefit, especially in emergency situations. We recommend an extensive long-term study of these

Localizing ECoG electrodes on the cortical anatomy without post-implantation imaging.

PubMed

Gupta, Disha; Hill, N Jeremy; Adamo, Matthew A; Ritaccio, Anthony; Schalk, Gerwin

2014-01-01

Electrocorticographic (ECoG) grids are placed subdurally on the cortex in people undergoing cortical resection to delineate eloquent cortex. ECoG signals have high spatial and temporal resolution and thus can be valuable for neuroscientific research. The value of these data is highest when they can be related to the cortical anatomy. Existing methods that establish this relationship rely either on post-implantation imaging using computed tomography (CT), magnetic resonance imaging (MRI) or X-Rays, or on intra-operative photographs. For research purposes, it is desirable to localize ECoG electrodes on the brain anatomy even when post-operative imaging is not available or when intra-operative photographs do not readily identify anatomical landmarks. We developed a method to co-register ECoG electrodes to the underlying cortical anatomy using only a pre-operative MRI, a clinical neuronavigation device (such as BrainLab VectorVision), and fiducial markers. To validate our technique, we compared our results to data collected from six subjects who also had post-grid implantation imaging available. We compared the electrode coordinates obtained by our fiducial-based method to those obtained using existing methods, which are based on co-registering pre- and post-grid implantation images. Our fiducial-based method agreed with the MRI-CT method to within an average of 8.24 mm (mean, median = 7.10 mm) across 6 subjects in 3 dimensions. It showed an average discrepancy of 2.7 mm when compared to the results of the intra-operative photograph method in a 2D coordinate system. As this method does not require post-operative imaging such as CTs, our technique should prove useful for research in intra-operative single-stage surgery scenarios. To demonstrate the use of our method, we applied our method during real-time mapping of eloquent cortex during a single-stage surgery. The results demonstrated that our method can be applied intra-operatively in the absence of post

Automatic M1-SO Montage Headgear for Transcranial Direct Current Stimulation (TDCS) Suitable for Home and High-Throughput In-Clinic Applications.

PubMed

Knotkova, Helena; Riggs, Alexa; Berisha, Destiny; Borges, Helen; Bernstein, Henry; Patel, Vaishali; Truong, Dennis Q; Unal, Gozde; Arce, Denis; Datta, Abhishek; Bikson, Marom

2018-05-15

Non-invasive transcranial direct current stimulation (tDCS) over the motor cortex is broadly investigated to modulate functional outcomes such as motor function, sleep characteristics, or pain. The most common montages that use two large electrodes (25-35 cm 2 ) placed over the area of motor cortex and contralateral supraorbital region (M1-SO montages) require precise measurements, usually using the 10-20 EEG system, which is cumbersome in clinics and not suitable for applications by patients at home. The objective was to develop and test novel headgear allowing for reproduction of the M1-SO montage without the 10-20 EEG measurements, neuronavigation, or TMS. Points C3/C4 of the 10-20 EEG system is the conventional reference for the M1 electrode. The headgear was designed using an orthogonal, fixed-angle approach for connection of frontal and coronal headgear components. The headgear prototype was evaluated for accuracy and replicability of the M1 electrode position in 600 repeated measurements compared to manually determined C3 in 30 volunteers. Computational modeling was used to estimate brain current flow at the mean and maximum recorded electrode placement deviations from C3. The headgear includes navigational points for accurate placement and assemblies to hold electrodes in the M1-SO position without measurement by the user. Repeated measurements indicated accuracy and replicability of the electrode position: the mean [SD] deviation of the M1 electrode (size 5 × 5 cm) from C3 was 1.57 [1.51] mm, median 1 mm. Computational modeling suggests that the potential deviation from C3 does not produce a significant change in brain current flow. The novel approach to M1-SO montage using a fixed-angle headgear not requiring measurements by patients or caregivers facilitates tDCS studies in home settings and can replace cumbersome C3 measurements for clinical tDCS applications. © 2018 International Neuromodulation Society.

Development of modified intraoperative examination monitor for awake surgery (IEMAS) system for awake craniotomy during brain tumor resection.

PubMed

Yoshimitsu, Kitaro; Suzuki, Takashi; Muragaki, Yoshihiro; Chernov, Mikhail; Iseki, Hiroshi

2010-01-01

Gliomas represent the most frequent type of primary intracranial tumors, which originate from the brain tissue itself, have infiltrative growth, unclear borders, and usually affect functionally-important cerebral structures. From March 2000 till March 2010, 839 neurosurgical procedures directed on resection of such neoplasms were performed in the intelligent operating theater of Tokyo Women's Medical University with the use of intraoperative MRI, real-time updated neuronavigation system, and Hi-vision operative microscope. To facilitate maximal possible tumor resection with minimal risk of neurological morbidity a special device, called Intraoperative Examination Monitor for Awake Surgery (IEMAS) was developed by us. It provides an opportunity to visualize a wide spectrum of inraoperative information related to condition of the patient, nuances of the surgical procedure, and details of the cortical mapping. The wide set of both anatomical and functional parameters, such as view of the patient's mimic and face movements during answering on the specific questions, type of examination test, position of the surgical instruments, parameters of the bispectral index monitor, and general view of the surgical field through the operating microscope and/or endoscope, is presented compactly in one screen with several displays, which allows fast integrated real-time analysis of the multiple data, nearly without interruption of the surgical manipulations. All members of the surgical team can share this information using several in-room liquid crystal displays. However, the initially designed IEMAS system was occasionally affected by interruption or detachment of the connecting cables, which could interfere with effective advancement of the surgical procedure. To avoid this problem a modified device was created. Its specific feature is wireless information transmitting function attained by incorporation of transmitters with a frequency range of 2.4 GHz. The clinical testing of t

Preoperative diffusion tensor imaging-fiber tracking for facial nerve identification in vestibular schwannoma: a systematic review on its evolution and current status with a pooled data analysis of surgical concordance rates.

PubMed

Savardekar, Amey R; Patra, Devi P; Thakur, Jai D; Narayan, Vinayak; Mohammed, Nasser; Bollam, Papireddy; Nanda, Anil

2018-03-01

cases). Larger studies with DTI-FT-integrated neuronavigation are required to look at the direct benefit offered by this specific technique in preserving postoperative FN function.

Intraoperative computed tomography with integrated navigation system in a multidisciplinary operating suite.

PubMed

Uhl, Eberhard; Zausinger, Stefan; Morhard, Dominik; Heigl, Thomas; Scheder, Benjamin; Rachinger, Walter; Schichor, Christian; Tonn, Jörg-Christian

2009-05-01

We report our preliminary experience in a prospective series of patients with regard to feasibility, work flow, and image quality using a multislice computed tomographic (CT) scanner combined with a frameless neuronavigation system (NNS). A sliding gantry 40-slice CT scanner was installed in a preexisting operating room. The scanner was connected to a frameless infrared-based NNS. Image data was transferred directly from the scanner into the navigation system. This allowed updating of the NNS during surgery by automated image registration based on the position of the gantry. Intraoperative CT angiography was possible. The patient was positioned on a radiolucent operating table that fits within the bore of the gantry. During image acquisition, the gantry moved over the patient. This table allowed all positions and movements like any normal operating table without compromising the positioning of the patient. For cranial surgery, a carbon-made radiolucent head clamp was fixed to the table. Experience with the first 230 patients confirms the feasibility of intraoperative CT scanning (136 patients with intracranial pathology, 94 patients with spinal lesions). After a specific work flow, interruption of surgery for intraoperative scanning can be limited to 10 to 15 minutes in cranial surgery and to 9 minutes in spinal surgery. Intraoperative imaging changed the course of surgery in 16 of the 230 cases either because control CT scans showed suboptimal screw position (17 of 307 screws, with 9 in 7 patients requiring correction) or that tumor resection was insufficient (9 cases). Intraoperative CT angiography has been performed in 7 cases so far with good image quality to determine residual flow in an aneurysm. Image quality was excellent in spinal and cranial base surgery. The system can be installed in a preexisting operating environment without the need for special surgical instruments. It increases the safety of the patient and the surgeon without necessitating a change

Minimally invasive superficial temporal artery to middle cerebral artery bypass through a minicraniotomy: benefit of three-dimensional virtual reality planning using magnetic resonance angiography.

PubMed

Fischer, Gerrit; Stadie, Axel; Schwandt, Eike; Gawehn, Joachim; Boor, Stephan; Marx, Juergen; Oertel, Joachim

2009-05-01

The aim of the authors in this study was to introduce a minimally invasive superficial temporal artery to middle cerebral artery (STA-MCA) bypass surgery by the preselection of appropriate donor and recipient branches in a 3D virtual reality setting based on 3-T MR angiography data. An STA-MCA anastomosis was performed in each of 5 patients. Before surgery, 3-T MR imaging was performed with 3D magnetization-prepared rapid acquisition gradient echo sequences, and a high-resolution CT 3D dataset was obtained. Image fusion and the construction of a 3D virtual reality model of each patient were completed. In the 3D virtual reality setting, the skin surface, skull surface, and extra- and intracranial arteries as well as the cortical brain surface could be displayed in detail. The surgical approach was successfully visualized in virtual reality. The anatomical relationship of structures of interest could be evaluated based on different values of translucency in all cases. The closest point of the appropriate donor branch of the STA and the most suitable recipient M(3) or M(4) segment could be calculated with high accuracy preoperatively and determined as the center point of the following minicraniotomy. Localization of the craniotomy and the skin incision on top of the STA branch was calculated with the system, and these data were transferred onto the patient's skin before surgery. In all cases the preselected arteries could be found intraoperatively in exact agreement with the preoperative planning data. Successful extracranial-intracranial bypass surgery was achieved without stereotactic neuronavigation via a preselected minimally invasive approach in all cases. Subsequent enlargement of the craniotomy was not necessary. Perioperative complications were not observed. All bypasses remained patent on follow-up. With the application of a 3D virtual reality planning system, the extent of skin incision and tissue trauma as well as the size of the bone flap was minimal. The

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

PubMed

Steinmeier, R; Fahlbusch, R; Ganslandt, O; Nimsky, C; Buchfelder, M; Kaus, M; Heigl, T; Lenz, G; Kuth, R; Huk, W

1998-10-01

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. All patients were surgically treated in a "twin operating theater," consisting of a conventional operating theater with complete neuronavigation equipment (StealthStation and MKM), which allowed surgery with magnetically incompatible instruments, conventional instrumentation and operating microscope, and a radiofrequency-shielded operating room designed for use with an intraoperative MRI scanner (Magnetom Open; Siemens AG, Erlangen, Germany). The Magnetom Open is a 0.2-T MRI scanner with a resistive magnet and specific adaptations that are necessary to integrate the scanner into the surgical environment. The operating theaters lie close together, and patients can be intraoperatively transported from one room to the other. This retrospective analysis includes 55 patients with cerebral lesions, all of whom were surgically treated between March 1996 and September 1997. Thirty-one patients with supratentorial tumors were surgically treated (with navigational guidance) in the conventional operating room, with intraoperative MRI for resection control. For 5 of these 31 patients, intraoperative resection control revealed significant tumor remnants, which led to further tumor resection guided by the information provided by intraoperative MRI. Intraoperative MRI resection control was performed in 18 transsphenoidal operations. In cases with suspected tumor remnants, the surgeon reexplored the sellar region; additional tumor tissue was removed in three of five cases. Follow-up scans were obtained for all patients 1 week and 2 to 3 months after surgery. For 14 of the 18 patients, the images obtained intraoperatively were comparable to those obtained after

[Application of individually designed trans-fissure approach in brain surgery: analysis of 90 cases].

PubMed

Zhao, Ji-Zong; Wang, Shuo; Zhang, Mao-Zhi; Wang, Lei; Wang, Rong; Tang, Ya-Juan

2009-01-06

To explore the feasibility and value of trans-fissure approaches in brain surgery through individually designed craniotomy. Ninety patients with intracranial space-occupying lesions, 47 males and 58 females, aged (43 +/- 14) (1 - 68), were treated by individualized trans-fissure approach surgeries. Linear scalp incision or "horseshoe shape" scalp incision were designed to perform the operation, with a bone flap 3 - 4 cm in diameter. The shortest approach to reach the lesion was decided under the guidance of neuro-navigation and real-time B-mode ultrasonography. Then the lesions were removed through natural cortical fissures. Another 79 patients with intracranial space-occupying lesions, 53 males and 51 females, aged (42 +/- 11) (15 -73), undergoing classical surgeries in the same period were used as control group. The average operation time, size of bone flap, amount of blood loss, hospitalization time, and hospitalization cost were compared between these 2 groups. The operation time of the individually designed trans-fissure approach group was (3.1 +/- 1.6) hours (1.33 - 10.83 hours), significantly shorter than that of the control group [(4.8 +/- 1.9) hrs, P < 0.05]. The amount of blood loss of the individually designed trans-fissure approach group was (173 +/- 168) ml (20 m - 500 ml), significantly less than that of the control group [(410 +/- 61) ml, P < 0.01]. The size of bone flap of the individually designed trans-fissure approach group was (12 +/- 5) cm2 [(1 - 25) cm2], significantly smaller than that of the control group [(20. +/- 9) cm2, P < 0.01]. Four of the 90 patients of the individually designed trans-fissure approach group received retransfusion, compared to 15 in the control group, during operation. No infection or other significant complications occurred after operation in the individually designed trans-fissure approach group. The hospitalization time of the individually designed trans-fissure approach group was (20 +/- 6) days (9 - 39 days

Improved nTMS- and DTI-derived CST tractography through anatomical ROI seeding on anterior pontine level compared to internal capsule

PubMed Central

Weiss, Carolin; Tursunova, Irada; Neuschmelting, Volker; Lockau, Hannah; Nettekoven, Charlotte; Oros-Peusquens, Ana-Maria; Stoffels, Gabriele; Rehme, Anne K.; Faymonville, Andrea Maria; Shah, N. Jon; Langen, Karl Josef; Goldbrunner, Roland; Grefkes, Christian

2015-01-01

Imaging of the course of the corticospinal tract (CST) by diffusion tensor imaging (DTI) is useful for function-preserving tumour surgery. The integration of functional localizer data into tracking algorithms offers to establish a direct structure–function relationship in DTI data. However, alterations of MRI signals in and adjacent to brain tumours often lead to spurious tracking results. We here compared the impact of subcortical seed regions placed at different positions and the influences of the somatotopic location of the cortical seed and clinical co-factors on fibre tracking plausibility in brain tumour patients. The CST of 32 patients with intracranial tumours was investigated by means of deterministic DTI and neuronavigated transcranial magnetic stimulation (nTMS). The cortical seeds were defined by the nTMS hot spots of the primary motor area (M1) of the hand, the foot and the tongue representation. The CST originating from the contralesional M1 hand area was mapped as intra-individual reference. As subcortical region of interests (ROI), we used the posterior limb of the internal capsule (PLIC) and/or the anterior inferior pontine region (aiP). The plausibility of the fibre trajectories was assessed by a-priori defined anatomical criteria. The following potential co-factors were analysed: Karnofsky Performance Scale (KPS), resting motor threshold (RMT), T1-CE tumour volume, T2 oedema volume, presence of oedema within the PLIC, the fractional anisotropy threshold (FAT) to elicit a minimum amount of fibres and the minimal fibre length. The results showed a higher proportion of plausible fibre tracts for the aiP-ROI compared to the PLIC-ROI. Low FAT values and the presence of peritumoural oedema within the PLIC led to less plausible fibre tracking results. Most plausible results were obtained when the FAT ranged above a cut-off of 0.105. In addition, there was a strong effect of somatotopic location of the seed ROI; best plausibility was obtained for the

Stereotactic probability and variability of speech arrest and anomia sites during stimulation mapping of the language dominant hemisphere.

PubMed

Chang, Edward F; Breshears, Jonathan D; Raygor, Kunal P; Lau, Darryl; Molinaro, Annette M; Berger, Mitchel S

2017-01-01

OBJECTIVE Functional mapping using direct cortical stimulation is the gold standard for the prevention of postoperative morbidity during resective surgery in dominant-hemisphere perisylvian regions. Its role is necessitated by the significant interindividual variability that has been observed for essential language sites. The aim in this study was to determine the statistical probability distribution of eliciting aphasic errors for any given stereotactically based cortical position in a patient cohort and to quantify the variability at each cortical site. METHODS Patients undergoing awake craniotomy for dominant-hemisphere primary brain tumor resection between 1999 and 2014 at the authors' institution were included in this study, which included counting and picture-naming tasks during dense speech mapping via cortical stimulation. Positive and negative stimulation sites were collected using an intraoperative frameless stereotactic neuronavigation system and were converted to Montreal Neurological Institute coordinates. Data were iteratively resampled to create mean and standard deviation probability maps for speech arrest and anomia. Patients were divided into groups with a "classic" or an "atypical" location of speech function, based on the resultant probability maps. Patient and clinical factors were then assessed for their association with an atypical location of speech sites by univariate and multivariate analysis. RESULTS Across 102 patients undergoing speech mapping, the overall probabilities of speech arrest and anomia were 0.51 and 0.33, respectively. Speech arrest was most likely to occur with stimulation of the posterior inferior frontal gyrus (maximum probability from individual bin = 0.025), and variance was highest in the dorsal premotor cortex and the posterior superior temporal gyrus. In contrast, stimulation within the posterior perisylvian cortex resulted in the maximum mean probability of anomia (maximum probability = 0.012), with large variance

Efficacy of intermittent Theta Burst Stimulation (iTBS) and 10-Hz high-frequency repetitive transcranial magnetic stimulation (rTMS) in treatment-resistant unipolar depression: study protocol for a randomised controlled trial.

PubMed

Bulteau, Samuel; Sébille, Veronique; Fayet, Guillemette; Thomas-Ollivier, Veronique; Deschamps, Thibault; Bonnin-Rivalland, Annabelle; Laforgue, Edouard; Pichot, Anne; Valrivière, Pierre; Auffray-Calvier, Elisabeth; Fortin, June; Péréon, Yann; Vanelle, Jean-Marie; Sauvaget, Anne

2017-01-13

The treatment of depression remains a challenge since at least 40% of patients do not respond to initial antidepressant therapy and 20% present chronic symptoms (more than 2 years despite standard treatment administered correctly). Repetitive transcranial magnetic stimulation (rTMS) is an effective adjuvant therapy but still not ideal. Intermittent Theta Burst Stimulation (iTBS), which has only been used recently in clinical practice, could have a faster and more intense effect compared to conventional protocols, including 10-Hz high-frequency rTMS (HF-rTMS). However, no controlled study has so far highlighted the superiority of iTBS in resistant unipolar depression. This paper focuses on the design of a randomised, controlled, double-blind, single-centre study with two parallel arms, carried out in France, in an attempt to assess the efficacy of an iTBS protocol versus a standard HF- rTMS protocol. Sixty patients aged between 18 and 75 years of age will be enrolled. They must be diagnosed with major depressive disorder persisting despite treatment with two antidepressants at an effective dose over a period of 6 weeks during the current episode. The study will consist of two phases: a treatment phase comprising 20 sessions of rTMS to the left dorsolateral prefrontal cortex, localised via a neuronavigation system and a 6-month longitudinal follow-up. The primary endpoint will be the number of responders per group, defined by a decrease of at least 50% in the initial score on the Montgomery and Asberg Rating Scale (MADRS) at the end of rTMS sessions. The secondary endpoints will be: response rate 1 month after rTMS sessions; number of remissions defined by a MADRS score of <8 at the endpoint and 1 month after; the number of responses and remissions maintained over the next 6 months; quality of life; and the presence of predictive markers of the therapeutic response: clinical (dimensional scales), neuropsychological (evaluation of cognitive functions), motor

The future of cerebral surgery: a kaleidoscope of opportunities.

PubMed

Elder, James B; Hoh, Daniel J; Oh, Bryan C; Heller, A Chris; Liu, Charles Y; Apuzzo, Michael L J

2008-06-01

The emerging future of cerebral surgery will witness the refined evolution of current techniques, as well as the introduction of numerous novel concepts. Clinical practice and basic science research will benefit greatly from their application. The sum of these efforts will result in continued minimalism and improved accuracy and efficiency of neurosurgical diagnostic and therapeutic methodologies.Initially, the refinement of current technologies will further enhance various aspects of cerebral surgery. Advances in computing power and information technology will speed data acquisition, storage, and transfer. Miniaturization of current devices will impact diverse areas, such as modulation of endoscopy and endovascular techniques. The increased penetrance of surgical technologies such as stereotactic radiosurgery, neuronavigation, intraoperative imaging, and implantable electrodes for neurodegenerative disorders and epilepsy will enhance the knowledge and experience in these areas and facilitate refinements and advances in these technologies. Further into the future, technologies that are currently relatively remote to surgical events will fundamentally alter the complexity and scale at which a neurological disease may be treated or investigated. Seemingly futuristic concepts will become ubiquitous in the daily experience of the neurosurgeon. These include diverse fields such as nanotechnology, virtual reality, and robotics. Ultimately, combining advances in multiple fields will yield progress in diverse realms such as brain tumor therapy, neuromodulation for psychiatric diseases, and neuroprosthetics. Operating room equipment and design will benefit from each of the aforementioned advances. In this work, we discuss new developments in three parts. In Part I, concepts in minimalism important for future cerebral surgery are discussed. These include concrete and abstract ideas in miniaturization, as well as recent and future work in microelectromechanical systems and

Automated Whole Brain Tractography Affects Preoperative Surgical Decision Making.

PubMed

Zakaria, Hesham; Haider, Sameah; Lee, Ian

2017-09-06

Surgery in and around eloquent brain structures poses a technical challenge when the goal of surgery is maximal safe resection. Magnetic resonance imaging (MRI) has revolutionized the diagnosis and treatment of neurological disorders, but tractography still remains limited in terms of utility because of the requisite manual labor and time required combined with the high risk of bias and inaccuracy. Automated whole brain tractography (AWBT) has simplified this workflow, overcoming historical barriers, and allowing for integration into modern neuronavigation. However, current literature showing the usefulness of this new technology is limited. In this study, we aimed to illustrate the utility of AWBT during cranial surgery and its ability to affect presurgical and intraoperative clinical decision making. We performed a retrospective chart review of cases that underwent AWBT for one year from July 2016 to July 2017. All patients underwent conventional anatomic MRI with and without contrast sequences, in addition to diffusion tensor imaging (DTI) on a 3 Tesla MRI scanner (Ingenia 3.0T, Philips, Amsterdam NL). Post-hoc AWBT processing was performed on a separate workstation. Patients were subsequently grouped into those that had undergone either language or motor mapping and those that did not. We compared both sets of patients to see any differences in patient age, sex, laterality of surgery, depth of resection from cortical surface, and smallest distance between the lesion and adjacent eloquent white matter tracts. We identified illustrative cases which demonstrated the ability of AWBT to affect surgical decision making. In this single-center series, we identified 73 total patients who underwent AWBT for intracranial surgery, of which 28 patients underwent either speech or language mapping. When comparing mapping to non-mapping patients, we found no difference with respect to age, gender, laterality of surgery, or whether the surgery was a revision. The distance

Laparoscopic anatomy of the autonomic nerves of the pelvis and the concept of nerve-sparing surgery by direct visualization of autonomic nerve bundles.

PubMed

Lemos, Nucelio; Souza, Caroline; Marques, Renato Moretti; Kamergorodsky, Gil; Schor, Eduardo; Girão, Manoel J B C

2015-11-01

To demonstrate the laparoscopic neuroanatomy of the autonomic nerves of the pelvis using the laparoscopic neuronavigation technique, as well as the technique for a nerve-sparing radical endometriosis surgery. Step-by-step explanation of the technique using videos and pictures (educational video) to demonstrate the anatomy of the intrapelvic bundles of the autonomic nerve system innervating the bladder, rectum, and pelvic floor. Tertiary referral center. One 37-year-old woman with an infiltrative endometriotic nodule on the anterior third of the left uterosacral ligament and one 34-year-old woman with rectovaginal endometriosis. Exposure and preservation by direct visualization of the hypogastric nerve and the inferior hypogastric plexus. Visual control and identification of the autonomic nerve branches of the posterior pelvis. Exposure and preservation of the hypogastric nerve and the superficial part of the left hypogastric nerve were achieved on the first patient. Nerve roots S2, S3, and S4 were identified on the second patient, allowing for the exposure and preservation of the pelvic splanchnic nerves and the deep portion inferior hypogastric plexus. Radical surgery for endometriosis can induce urinary dysfunction in 2.4%-17.5% of patients owing to lesion of the autonomic nerves. The surgeon's knowledge of the anatomy of these nerves is the main factor for preserving postoperative urinary function. The following nerves are the intrapelvic part of the autonomic nervous system: the hypogastric nerves, which derive from the superior hypogastric plexus and carry the sympathetic signals to the internal urethral and anal sphincters as well as to the pelvic visceral proprioception; and the pelvic splanchnic nerves, which arise from S2 to S4 and carry nociceptive and parasympathetic signals to the bladder, rectum, and the sigmoid and left colons. The hypogastric and pelvic splanchnic nerves merge into the pararectal fossae to form the inferior hypogastric plexus. Most

Coregistered fluorescence-enhanced tumor resection of malignant glioma: relationships between δ-aminolevulinic acid–induced protoporphyrin IX fluorescence, magnetic resonance imaging enhancement, and neuropathological parameters

PubMed Central

Roberts, David W.; Valdés, Pablo A.; Harris, Brent T.; Fontaine, Kathryn M.; Hartov, Alexander; Fan, Xiaoyao; Ji, Songbai; Lollis, S. Scott; Pogue, Brian W.; Leblond, Frederic; Tosteson, Tor D.; Wilson, Brian C.; Paulsen, Keith D.

2010-01-01

Object The aim of this study was to investigate the relationships between intraoperative fluorescence, features on MR imaging, and neuropathological parameters in 11 cases of newly diagnosed glioblastoma multiforme (GBM) treated using protoporphyrin IX (PpIX) fluorescence-guided resection. Methods In 11 patients with a newly diagnosed GBM, δ-aminolevulinic acid (ALA) was administered to enhance endogenous synthesis of the fluorophore PpIX. The patients then underwent fluorescence-guided resection, coregistered with conventional neuronavigational image guidance. Biopsy specimens were collected at different times during surgery and assigned a fluorescence level of 0–3 (0, no fluorescence; 1, low fluorescence; 2, moderate fluorescence; or 3, high fluorescence). Contrast enhancement on MR imaging was quantified using two image metrics: 1) Gd-enhanced signal intensity (GdE) on T1-weighted subtraction MR image volumes, and 2) normalized contrast ratios (nCRs) in T1-weighted, postGd-injection MR image volumes for each biopsy specimen, using the biopsy-specific image-space coordinate transformation provided by the navigation system. Subsequently, each GdE and nCR value was grouped into one of two fluorescence categories, defined by its corresponding biopsy specimen fluorescence assessment as negative fluorescence (fluorescence level 0) or positive fluorescence (fluorescence level 1, 2, or 3). A single neuropathologist analyzed the H & E–stained tissue slides of each biopsy specimen and measured three neuropathological parameters: 1) histopathological score (0–IV); 2) tumor burden score (0–III); and 3) necrotic burden score (0–III). Results Mixed-model analyses with random effects for individuals show a highly statistically significant difference between fluorescing and nonfluorescing tissue in GdE (mean difference 8.33, p = 0.018) and nCRs (mean difference 5.15, p < 0.001). An analysis of association demonstrated a significant relationship between the levels of

Intraoperative computed tomography with an integrated navigation system in stabilization surgery for complex craniovertebral junction malformation.

PubMed

Yu, Xinguang; Li, Lianfeng; Wang, Peng; Yin, Yiheng; Bu, Bo; Zhou, Dingbiao

2014-07-01

This study was designed to report our preliminary experience with stabilization procedures for complex craniovertebral junction malformation (CVJM) using intraoperative computed tomography (iCT) with an integrated neuronavigation system (NNS). To evaluate the workflow, feasibility and clinical outcome of stabilization procedures using iCT image-guided navigation for complex CVJM. The stabilization procedures in CVJM are complex because of the area's intricate geometry and bony structures, its critical relationship to neurovascular structures and the intricate biomechanical issues involved. A sliding gantry 40-slice computed tomography scanner was installed in a preexisting operating room. The images were transferred directly from the scanner to the NNS using an automated registration system. On the basis of the analysis of intraoperative computed tomographic images, 23 cases (11 males, 12 females) with complicated CVJM underwent navigated stabilization procedures to allow more control over screw placement. The age of these patients were 19-52 years (mean: 33.5 y). We performed C1-C2 transarticular screw fixation in 6 patients to produce atlantoaxial arthrodesis with better reliability. Because of a high-riding transverse foramen on at least 1 side of the C2 vertebra and an anomalous vertebral artery position, 7 patients underwent C1 lateral mass and C2 pedicle screw fixation. Ten additional patients were treated with individualized occipitocervical fixation surgery from the hypoplasia of C1 or constraints due to C2 bone structure. In total, 108 screws were inserted into 23 patients using navigational assistance. The screws comprised 20 C1 lateral mass screws, 26 C2, 14 C3, or 4 C4 pedicle screws, 32 occipital screws, and 12 C1-C2 transarticular screws. There were no vascular or neural complications except for pedicle perforations that were detected in 2 (1.9%) patients and were corrected intraoperatively without any persistent nerves or vessel damage. The overall

Introduction of a standardized multimodality image protocol for navigation-guided surgery of suspected low-grade gliomas.

PubMed

Mert, Aygül; Kiesel, Barbara; Wöhrer, Adelheid; Martínez-Moreno, Mauricio; Minchev, Georgi; Furtner, Julia; Knosp, Engelbert; Wolfsberger, Stefan; Widhalm, Georg

2015-01-01

OBJECT Surgery of suspected low-grade gliomas (LGGs) poses a special challenge for neurosurgeons due to their diffusely infiltrative growth and histopathological heterogeneity. Consequently, neuronavigation with multimodality imaging data, such as structural and metabolic data, fiber tracking, and 3D brain visualization, has been proposed to optimize surgery. However, currently no standardized protocol has been established for multimodality imaging data in modern glioma surgery. The aim of this study was therefore to define a specific protocol for multimodality imaging and navigation for suspected LGG. METHODS Fifty-one patients who underwent surgery for a diffusely infiltrating glioma with nonsignificant contrast enhancement on MRI and available multimodality imaging data were included. In the first 40 patients with glioma, the authors retrospectively reviewed the imaging data, including structural MRI (contrast-enhanced T1-weighted, T2-weighted, and FLAIR sequences), metabolic images derived from PET, or MR spectroscopy chemical shift imaging, fiber tracking, and 3D brain surface/vessel visualization, to define standardized image settings and specific indications for each imaging modality. The feasibility and surgical relevance of this new protocol was subsequently prospectively investigated during surgery with the assistance of an advanced electromagnetic navigation system in the remaining 11 patients. Furthermore, specific surgical outcome parameters, including the extent of resection, histological analysis of the metabolic hotspot, presence of a new postoperative neurological deficit, and intraoperative accuracy of 3D brain visualization models, were assessed in each of these patients. RESULTS After reviewing these first 40 cases of glioma, the authors defined a specific protocol with standardized image settings and specific indications that allows for optimal and simultaneous visualization of structural and metabolic data, fiber tracking, and 3D brain