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Sample records for neuronavigation

  1. [How Reliable is Neuronavigation?].

    PubMed

    Stieglitz, Lennart Henning

    2016-02-17

    Neuronavigation plays a central role in modern neurosurgery. It allows visualizing instruments and three-dimensional image data intraoperatively and supports spatial orientation. Thus it allows to reduce surgical risks and speed up complex surgical procedures. The growing availability and importance of neuronavigation makes clear how relevant it is to know about its reliability and accuracy. Different factors may influence the accuracy during the surgery unnoticed, misleading the surgeon. Besides the best possible optimization of the systems themselves, a good knowledge about its weaknesses is mandatory for every neurosurgeon.

  2. Neuronavigation: geneology, reality, and prospects.

    PubMed

    Enchev, Yavor

    2009-09-01

    Currently, neuronavigation is an indivisible and indispensable part of the neurosurgical reality with a significant potential impact in each neurosurgical procedure. The history of neuronavigation is quite short (< 3 decades), but full of highly promising achievements. The advent of neuronavigation would be unimaginable without the development of imaging technology, electronics, robotics, and space technology. The history of neuroradiology is reviewed briefly parallel with the detailed evolution of frame-based stereotaxy and its successor-neuronavigation. The historic milestones and the state of the art of neuronavigation are discussed in a genealogical manner. The future trends of neuronavigation as integrated with intraoperative CT, MR, and ultrasonography, as well as with robotic systems are outlined.

  3. First neuronavigation experiences in Uruguay.

    PubMed

    Carbajal, Guillermo; Gomez, Alvaro; Pereyra, Gabriela; Lima, Ramiro; Preciozzi, Javier; Vazquez, Luis; Villar, Alvaro

    2010-01-01

    Neuronavigation is the application of image guidance to neurosurgery where the position of a surgical tool can be displayed on a preoperative image. Although this technique has been used worldwide in the last ten years, it was never applied in Uruguay due to its cost. In an ongoing project, the Engineering Faculty (Universidad de la República), the Hospital de Clínicas (Medicine Faculty - Universidad de la República) and the Regional Hospital of Tacuarembó are doing the first experimental trials in neuronavigation. In this project, a prototype based on optical tracking equipment and the open source software IGSTK (Image Guided Surgery Toolkit) is under development and testing.

  4. [Neuronavigation in the surgical planning of callosotomy].

    PubMed

    Valencia Calderón, Carlos; Castro Cevallos, Alfredo; Calderón Valdiviezo, Ana; Escobar Dávila, Roberto; Parra Rosales, Fausto; Quispe Alcocer, Julio; Vásquez Hahn, Catalina

    2016-01-01

    To describe the usefulness of 3D computer-assisted preoperative neuronavigation for stereoscopic location of the venous sinuses, arterial branches, and corpus callosum, to extrapolate anatomical landmarks on the surgical field and make decisions before the intervention. A prospective analysis was performed on patients with refractory epilepsy who underwent neuronavigation-assisted callosotomy (BRAIN LAB Dual). A total of 10 neuronavigation-assisted callosotomies were performed in the year 2014. The ages of the patients (4 males and 6 females) were between 4 and 13 years (mean 7; SD 3.02). The most common indication for callosotomy in our sample was Lennox Gastoux (5 patients). A right parasagittal craniotomy was performed in 8 patients. An anterior two-thirds callosotomy was performed in 8 patients and anterior three-quarters in 2 patients. The mean accuracy of the neuronavigation procedure was less than 2mm. In no cases were there significant intraoperative surgical complications. Callosotomy using frameless guided neuronavigation is an accurate and safe technique in patients with epilepsy refractory to surgical resection. Copyright © 2015 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

  5. Intraventricular trigonal meningioma: Neuronavigation? No, thanks!

    PubMed Central

    Silva, Danilo O. A.; Matis, Georgios K.; Costa, Leonardo F.; Kitamura, Matheus A. P.; Birbilis, Theodossios A.; Azevedo Filho, Hildo R. C.

    2011-01-01

    Background: Most of the time meningiomas are benign brain tumors and surgical removal ensures cure in the vast majority of the cases. Thus, whenever possible, complete surgical resection should be the goal of the treatment. Methods: This is a report of our surgical technique for the operative resection of a trigonal meningioma in a resource-limited setting. The necessity of accurate and deep knowledge of the regional anatomy is outlined. Results: A 44-year-old male presented to our outpatient clinic complaining of cephalalgia increasing in frequency and intensity over the last month. His neurological exam was normal, yet a brain computed tomography scan revealed a lesion in the right trigone of the ventricular system. The diagnosis of possible meningioma was set. After thoroughly informing the patient, tumor resection was decided. An intraparietal sulcus approach was favored without the use of any modern technological aids such as intraoperative magnetic resonance imaging or neuronavigation. The postoperative course was uneventful and a postoperative computed tomography scan demonstrated the complete resection of the tumor. The patient was discharged two days later with no neurological deficits. In a two-year-follow-up he remains recurrence-free. Conclusion: In the current cost-effective era it is still possible to safely remove an intraventricular trigonal meningioma without the convenience of neuronavigation. Since the best neuronavigator is the profound neuroanatomical knowledge, no technological advancement could replace a well-educated and trained neurosurgeon. PMID:21886886

  6. Neuronavigation-assisted surgery for distal anterior cerebral artery aneurysm.

    PubMed

    Kim, T S; Joo, S P; Lee, J K; Jung, S; Kim, J H; Kim, S H; Kang, S S; Yoon, W

    2007-06-01

    We present our experience with the neuronavigation system as used for surgery of distal anterior cerebral artery (DACA) aneurysm. Between 2001 and 2004, 12 patients with a DACA aneurysm were consecutively treated with direct clipping assisted by the neuronavigation system. We used the BrainLAB Vector Vision neuronavigation system (BrainLAB, Heimstetten, Germany). Seven out of 12 patients presented with subarachnoid hemorrhage. Aneurysms were located at distal A2 in 10 patients and distal A3 in two patients. The size of the aneurysms ranged from 3-10 mm. There were no procedure-related complications or technical problems during application of the neuronavigation system. The registration accuracy ranged from 0.5-1.5 mm (mean: 0.88 mm). The neuronavigation system provided real-time presentation of the DACA and the aneurysm, and allowed for identification of the DACA aneurysm in all patients. No surgical complications developed, and all 12 patients had a good recovery after direct clipping. Although current neuronavigation systems are not available for all intracranial aneurysms, we believe that the DACA aneurysm is a good candidate for its use. The additional benefits of a small craniotomy and precise intraoperative orientation during surgery result in a minimally invasive aneurysm procedure.

  7. Optical Neuronavigation without Rigid Head Fixation During Awake Surgery.

    PubMed

    Freyschlag, Christian F; Kerschbaumer, Johannes; Eisner, Wilhelm; Pinggera, Daniel; Brawanski, Konstantin R; Petr, Ondra; Bauer, Marlies; Grams, Astrid E; Bodner, Thomas; Seiz, Marcel; Thomé, Claudius

    2017-01-01

    Optical neuronavigation without rigid pin fixation of the head may lead to inaccurate results because of the patient's movements during awake surgery. In this study, we report our results using a skull-mounted reference array for optical tracking in patients undergoing awake craniotomy for eloquent gliomas. Between March 2013 and December 2014, 18 consecutive patients (10 men, 8 women) with frontotemporal (n = 16) or frontoparietal (perirolandic; n = 2) lesions underwent awake craniotomy without rigid pin fixation. All patients had a skull-mounted reference array for optical tracking placed on the forehead. Accuracy of navigation was determined with pointer tip deviation measurements on superficial and bony anatomic structures. Good accuracy was defined as a tip deviation <2 mm. Gross total resection (>98%) was achieved in 7 patients (38%); >90% of tumor was resected in 8 patients (44%). In 3 patients, only subtotal resection or biopsy was performed secondary to stimulation results. In all patients, good accuracy of the optical neuronavigation system could be demonstrated without intraoperative peculiarities or complications. The reference array had to be repositioned because of loosening in 1 patient. Neuronavigation could be reliably applied to support stimulation-based resection. A skull-mounted reference array is a simple and safe method for optical neuronavigation tracking without rigid pin fixation of the patient's head. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Neuronavigation in the surgical management of brain tumors: current and future trends

    PubMed Central

    Orringer, Daniel A; Golby, Alexandra; Jolesz, Ferenc

    2013-01-01

    Neuronavigation has become an ubiquitous tool in the surgical management of brain tumors. This review describes the use and limitations of current neuronavigational systems for brain tumor biopsy and resection. Methods for integrating intraoperative imaging into neuronavigational datasets developed to address the diminishing accuracy of positional information that occurs over the course of brain tumor resection are discussed. In addition, the process of integration of functional MRI and tractography into navigational models is reviewed. Finally, emerging concepts and future challenges relating to the development and implementation of experimental imaging technologies in the navigational environment are explored. PMID:23116076

  9. Neuronavigation-assisted transoral-transpharyngeal approach for basilar invagination--two case reports.

    PubMed

    Ugur, Hasan Caglar; Kahilogullari, Gokmen; Attar, Ayhan; Caglar, Sukru; Savas, Ali; Egemen, Nihat

    2006-06-01

    Two patients presented with congenital basilar invagination manifesting as progressive myelopathy. Both patients underwent surgery using a neuronavigation-assisted transoral-transpharyngeal approach. The Brain-LAB Vector Vision navigation system was used for image guidance. The registration accuracies were 0.9 and 1.3 mm. After decompression, posterior stabilization was performed. Both patients had an uneventful postoperative course. The transoral-transpharyngeal approach with the neuronavigation system provides safe exposure and decompression for basilar invagination.

  10. Preliminary study on the clinical application of augmented reality neuronavigation.

    PubMed

    Inoue, D; Cho, B; Mori, M; Kikkawa, Y; Amano, T; Nakamizo, A; Yoshimoto, K; Mizoguchi, M; Tomikawa, M; Hong, J; Hashizume, M; Sasaki, T

    2013-03-01

    To develop an augmented reality (AR) neuronavigation system with Web cameras and examine its clinical utility. The utility of the system was evaluated in three patients with brain tumors. One patient had a glioblastoma and two patients had convexity meningiomas. Our navigation system comprised the open-source software 3D Slicer (Brigham and Women's Hospital, Boston, Massachusetts, USA), the infrared optical tracking sensor Polaris (Northern Digital Inc., Waterloo, Canada), and Web cameras. We prepared two different types of Web cameras: a handheld type and a headband type. Optical markers were attached to each Web camera. We used this system for skin incision planning before the operation, during craniotomy, and after dural incision. We were able to overlay these images in all cases. In Case 1, accuracy could not be evaluated because the tumor was not on the surface, though it was generally suitable for the outline of the external ear and the skin. In Cases 2 and 3, the augmented reality error was ∼2 to 3 mm. AR technology was examined with Web cameras in neurosurgical operations. Our results suggest that this technology is clinically useful in neurosurgical procedures, particularly for brain tumors close to the brain surface. Georg Thieme Verlag KG Stuttgart · New York.

  11. 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.

  12. Ommaya reservoir with ventricular catheter placement for chemotherapy with frameless and pinless electromagnetic surgical neuronavigation.

    PubMed

    Weiner, Gregory M; Chivukula, Srinivas; Chen, Ching-Jen; Ding, Dale; Engh, Johnathan A; Amankulor, Nduka

    2015-03-01

    Accuracy in Ommaya reservoir catheter placement is critical to chemotherapy infusion. Most frameless image guidance is light emitting diode (LED) based, requiring a direct line of communication between instrument and tracker, limiting freedom of instrument movement within the surgical field. Electromagnetic neuronavigation may overcome this challenge. To compare Ommaya reservoir ventricular catheter placement using electromagnetic neuronavigation to LED-based optical navigation, with emphasis on placement accuracy, operative time and complication rate. Twenty-eight patients who underwent placement of Ommaya reservoirs at our institution between 2010 and 2014 with either electromagnetic (12 patients) or optical neuronavigation (16 patients) were retrospectively reviewed. Half of the patients were male. Their mean age was 56 years (range 28-87 years). Accuracy and precision in catheter tip placement at the target site (foramen of Monro) were both higher (p=0.038 and p=0.043, respectively) with electromagnetic neuronavigation. Unintended placement of the distal catheter contralateral to the target site occurred more frequently with optical navigation, as did superior or inferior positioning by more than 5 mm. Mean operative times were shorter (p=0.027) with electromagnetic neuronavigation (43.2 min) than with optical navigation (51.0 min). There were three complications (10.7%)--one case each of cytotoxic edema, post-operative wound infection, and urinary tract infection. The rate of complication did not differ between groups. In contrast with optical neuronavigation, frameless and pinless electromagnetic image guidance allows the ability to track instrument depth in real-time. It may increase ventricular catheter placement accuracy and precision, and decrease operative times. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Neuronavigated surgery of intracranial cavernomas--enthusiasm for high technologies or a gold standard?

    PubMed

    Enchev, Yavor P; Popov, Rumen V; Romansky, Kiril V; Marinov, Marin B; Bussarsky, Ventzeslav A

    2008-01-01

    The aim of this study was to investigate the effect of neuronavigation on the following parameters: "skin incision", "craniotomy", "intraoperative anatomical orientation", "dissection guiding", "localization of the pathological formation", "assessment of the degree of resection" and "duration of surgical procedure" in resections of intracranial cavernomas and to specify the indications for neuronavigation in their surgical treatment. The present prospective study included 20 patients with intracranial cavernomas who underwent neuronavigated surgery between March 2003 and December 2005 at the Clinic of Neurosurgery of the "St. I. Rilsky" University Hospital, Medical University, Sofia. The female/male ratio in the series was 9/11 (45%-55%). The patients' mean age was 27.96 +/- 11.61 years (age range 1.2 to 44 years). The patients were examined and followed up in a standard manner. Cavernous malformations were totally removed in 19 patients. One patient with thalamic cavernoma underwent navigated endoscopic biopsy. There was no morbidity or mortality associated with the method. Neuronavigation allowed precise localization and individual design of the skin incision and craniotomy. Neuronavigated intraoperative anatomical orientation, dissection guiding, localization of the pathological formation, and assessment of degree of resection were evaluated as markedly useful. They resulted in excellent surgery results and reduced operation time in comparison with the conventional surgery. In intracranial cavernomas frameless stereotaxy provides the surgeon with useful feedback in the preoperative anatomical orientation, the planning and simulation of surgical approach, the intraoperative navigation, in avoiding vital neurovascular structures, in the assessment of the degree of resection and the identification of possible residual parts. That is why cavernous malformations are among the most common indications for cranial neuronavigation.

  14. An MRS- and PET-guided biopsy tool for intraoperative neuronavigational systems.

    PubMed

    Grech-Sollars, Matthew; Vaqas, Babar; Thompson, Gerard; Barwick, Tara; Honeyfield, Lesley; O'Neill, Kevin; Waldman, Adam D

    2017-03-17

    OBJECTIVE Glioma heterogeneity and the limitations of conventional structural MRI for identifying aggressive tumor components can limit the reliability of stereotactic biopsy and, hence, tumor characterization, which is a hurdle for developing and selecting effective treatment strategies. In vivo MR spectroscopy (MRS) and PET enable noninvasive imaging of cellular metabolism relevant to proliferation and can detect regions of more highly active tumor. Here, the authors integrated presurgical PET and MRS with intraoperative neuronavigation to guide surgical biopsy and tumor sampling of brain gliomas with the aim of improving intraoperative tumor-tissue characterization and imaging biomarker validation. METHODS A novel intraoperative neuronavigation tool was developed as part of a study that aimed to sample high-choline tumor components identified by multivoxel MRS and (18)F-methylcholine PET-CT. Spatially coregistered PET and MRS data were integrated into structural data sets and loaded onto an intraoperative neuronavigation system. High and low choline uptake/metabolite regions were represented as color-coded hollow spheres for targeted stereotactic biopsy and tumor sampling. RESULTS The neurosurgeons found the 3D spherical targets readily identifiable on the interactive neuronavigation system. In one case, areas of high mitotic activity were identified on the basis of high (18)F-methylcholine uptake and elevated choline ratios found with MRS in an otherwise low-grade tumor, which revealed the possible use of this technique for tumor characterization. CONCLUSIONS These PET and MRI data can be combined and represented usefully for the surgeon in neuronavigation systems. This method enables neurosurgeons to sample tumor regions based on physiological and molecular imaging markers. The technique was applied for characterizing choline metabolism using MRS and (18)F PET; however, this approach provides proof of principle for using different radionuclide tracers and

  15. An MRS- and PET-guided biopsy tool for intraoperative neuronavigational systems.

    PubMed

    Grech-Sollars, Matthew; Vaqas, Babar; Thompson, Gerard; Barwick, Tara; Honeyfield, Lesley; O'Neill, Kevin; Waldman, Adam D

    2016-11-11

    OBJECTIVE Glioma heterogeneity and the limitations of conventional structural MRI for identifying aggressive tumor components can limit the reliability of stereotactic biopsy and, hence, tumor characterization, which is a hurdle for developing and selecting effective treatment strategies. In vivo MR spectroscopy (MRS) and PET enable noninvasive imaging of cellular metabolism relevant to proliferation and can detect regions of more highly active tumor. Here, the authors integrated presurgical PET and MRS with intraoperative neuronavigation to guide surgical biopsy and tumor sampling of brain gliomas with the aim of improving intraoperative tumor-tissue characterization and imaging biomarker validation. METHODS A novel intraoperative neuronavigation tool was developed as part of a study that aimed to sample high-choline tumor components identified by multivoxel MRS and (18)F-methylcholine PET-CT. Spatially coregistered PET and MRS data were integrated into structural data sets and loaded onto an intraoperative neuronavigation system. High and low choline uptake/metabolite regions were represented as color-coded hollow spheres for targeted stereotactic biopsy and tumor sampling. RESULTS The neurosurgeons found the 3D spherical targets readily identifiable on the interactive neuronavigation system. In one case, areas of high mitotic activity were identified on the basis of high (18)F-methylcholine uptake and elevated choline ratios found with MRS in an otherwise low-grade tumor, which revealed the possible use of this technique for tumor characterization. CONCLUSIONS These PET and MRI data can be combined and represented usefully for the surgeon in neuronavigation systems. This method enables neurosurgeons to sample tumor regions based on physiological and molecular imaging markers. The technique was applied for characterizing choline metabolism using MRS and (18)F PET; however, this approach provides proof of principle for using different radionuclide tracers and

  16. MRI Guided Brain Stimulation without the Use of a Neuronavigation System

    PubMed Central

    Vaghefi, Ehsan; Byblow, Winston D.; Stinear, Cathy M.; Thompson, Benjamin

    2015-01-01

    A key issue in the field of noninvasive brain stimulation (NIBS) is the accurate localization of scalp positions that correspond to targeted cortical areas. The current gold standard is to combine structural and functional brain imaging with a commercially available “neuronavigation” system. However, neuronavigation systems are not commonplace outside of specialized research environments. Here we describe a technique that allows for the use of participant-specific functional and structural MRI data to guide NIBS without a neuronavigation system. Surface mesh representations of the head were generated using Brain Voyager and vectors linking key anatomical landmarks were drawn on the mesh. Our technique was then used to calculate the precise distances on the scalp corresponding to these vectors. These calculations were verified using actual measurements of the head and the technique was used to identify a scalp position corresponding to a brain area localized using functional MRI. PMID:26413537

  17. Applications of neuronavigation system in cranial surgery: experience of a single center

    PubMed Central

    Nouri, Mohsen; Pahlavani, Mehrdad; Amirjamshidi, Abbas; Shirani-Bidabadi, Mohammad; Ketabchi, Ebrahim; Karimi-Yarandi, Kourosh

    2012-01-01

    Abstract: Background: Since the advent of navigational systems in neurosurgery, various implications have been introduced for them in spine and brain practices. Although, the range of surgeries in which these systems are being used is getting wider over time, their application is becoming more specific in certain situations. Methods: This means that defining specific indications for their usage is not as easy as it was previously thought. Brief reviewing of the available literature showed various navigation systems proposed and used in neurosurgery. Results: In this study, we review case selection criteria, techniques, and the results of neuronavigation applications in the patients underwent neurosurgical operations in the Sina hospital (Tehran, Iran) during 2011. Conclusions: The findings of our survey and experiences prove the efficacy and advantages of this technique that reduces the risk of neurovascular damage, neural tissue manipulation, operation time, and bleeding. Keywords: Neuronavigation, Cranial surgery, Navigational system

  18. Use of neuronavigation and electrophysiology in surgery of subcortically located lesions in the sensorimotor strip

    PubMed Central

    Eisner, W; Burtscher, J; Bale, R; Sweeney, R; Koppelstatter, F; Golaszewski, S; Kolbitsch, C; Twerdy, K

    2002-01-01

    Objectives: Subcortical lesions in the sensorimotor strip are often considered to be inoperable. The purpose of this study was to evaluate the usefulness of a combined approach for surgery in this region, aided by a robotic neuronavigation system under electrophysiological control. Methods: In a prospective study on 10 patients, space occupying lesions in the sensorimotor central area were removed using the Surgiscope® robotic navigation system and the Nicolet Viking IV® electrophysiological system. Results: Precise tumour localisation with the neuronavigation system and the information on the patient's cortical motor distribution obtained by bipolar cortical stimulation led to postoperative improvement in motor function in all but one patient. Seven of the patients had focal, defined pathology (four metastases; two cavernoma; one aspergilloma). Conclusion: Due to the implementation of two recent technologies, surgery of lesions in the subcortical sensorimotor region can be performed with greater confidence. PMID:11861700

  19. Biomechanical modeling provides more accurate data for neuronavigation than rigid registration

    PubMed Central

    Garlapati, Revanth Reddy; Roy, Aditi; Joldes, Grand Roman; Wittek, Adam; Mostayed, Ahmed; Doyle, Barry; Warfield, Simon Keith; Kikinis, Ron; Knuckey, Neville; Bunt, Stuart; Miller, Karol

    2015-01-01

    It is possible to improve neuronavigation during image-guided surgery by warping the high-quality preoperative brain images so that they correspond with the current intraoperative configuration of the brain. In this work, the accuracy of registration results obtained using comprehensive biomechanical models is compared to the accuracy of rigid registration, the technology currently available to patients. This comparison allows us to investigate whether biomechanical modeling provides good quality image data for neuronavigation for a larger proportion of patients than rigid registration. Preoperative images for 33 cases of neurosurgery were warped onto their respective intraoperative configurations using both biomechanics-based method and rigid registration. We used a Hausdorff distance-based evaluation process that measures the difference between images to quantify the performance of both methods of registration. A statistical test for difference in proportions was conducted to evaluate the null hypothesis that the proportion of patients for whom improved neuronavigation can be achieved, is the same for rigid and biomechanics-based registration. The null hypothesis was confidently rejected (p-value<10−4). Even the modified hypothesis that less than 25% of patients would benefit from the use of biomechanics-based registration was rejected at a significance level of 5% (p-value = 0.02). The biomechanics-based method proved particularly effective for cases experiencing large craniotomy-induced brain deformations. The outcome of this analysis suggests that our nonlinear biomechanics-based methods are beneficial to a large proportion of patients and can be considered for use in the operating theatre as one possible method of improving neuronavigation and surgical outcomes. PMID:24460486

  20. 5-aminolevulinic acid and neuronavigation in high-grade glioma surgery: results of a combined approach.

    PubMed

    Panciani, Pier Paolo; Fontanella, Marco; Garbossa, Diego; Agnoletti, Alessandro; Ducati, Alessandro; Lanotte, Michele

    2012-02-01

    In high-grade glioma surgery, several techniques are used to achieve the maximum cytoreductive treatment preserving neurological functions. However, the effectiveness of all the methods used alone is reduced by specific limitations of each. We assessed the reliability of a multimodal strategy based on 5-aminolevulinic acid (5-ALA) and neuronavigation. We prospectively studied 18 patients with suspected, non eloquent-area malignant gliomas amenable for complete resection. Conventional illumination was used until the excision appeared complete. The cavity was then systematically inspected in violet-blue light to identify any residual tumour. Multiple biopsies of both fluorescent and non-fluorescent tissue were performed in all cases. Each specimen was labelled according to the sampling location (inside or outside the boundary set by the neuronavigator). The samples were analysed by a neuropathologist blinded to the intraoperative classification. We reviewed the results of both methods, either singly or in combination. Individual analysis showed higher 5-ALA reliability compared to neuronavigation. However, several false-negative fluorescent specimens were detected. With the combined use of fluorescence and neuroimaging, only 1 sample (negative for both 5-ALA and navigation) was tumoral tissue. In our experience, the combined approach showed the best sensitivity and it is recommended in cases of lesions involving non-eloquent areas.

  1. Frameless neuronavigation using the ISG-system in practice: from craniotomy to delineation of lesion.

    PubMed

    Kleinpeter, G; Lothaller, C

    2003-10-01

    The overall performance of a "pointer" neuronavigation system (the ISG ALLEGRO Viewing Wand) in everyday surgical use was evaluated by investigating the practical utility of the technical set-up for one particular surgical task. The basis of the analysis was the numerical evaluation of four areas of fundamental importance for most brain surgery: site and size of craniotomy, localisation of lesion, the trajectory through the brain, and the delineation of the lesion. In a protocol of 65 patients we based our examination on a subjective 4-point rating scale ranging from 0 (= no help) to 3 (= very helpful) for each of the four above categories. We investigated the potential influence of three factors: the lesions histology (4 groups), its size (3 categories) and the depth from the cortical surface (3 levels). Our experience is that the histology of the lesions has significant influence on the relative usefulness of neuronavigation for craniotomy (P < 0.017) and for delineation of the lesion (P < 0.003). We found neuronavigation most helpful for removing gliomas. Second, this system was found to be very helpful in locating small, hitherto hard-to-find, lesions (P < 0.01). Lesion's depth had no effect on the ratings (P > 0.2). Overall, the use of this system led to more precise skin incisions, better site and size of craniotomies tailored to the pathology, the trajectory through the brain, and to more precise delineation of the lesion.

  2. [Neuronavigation-guided pure endoscopic endonasai transsphenoidal approach for pituitary adenomas].

    PubMed

    Hu, Changchen; Ji, Hongming; Zhang, Shiyuan; Hao, Xudong; Shen, Bo; Su, Luhai

    2015-02-03

    To explore the efficacies of neuronavigation-guided pure endoscopic endonasal transsphenoidal approach for removing pituitary adenomas. Retrospective analyses were conducted for the clinical data of 139 patients undergoing pure endoscopic endonasal transsphenoidal surgery for pituitary adenomas between July 2011 and July 2014. There were 55 males and 84 females with a mean age of 48. 9 (21 - 73) years. The classifications of Hardy-Wilson were I (n =16), II (n = 39), III (n = 48) and IV (n = 36). Neuronavigation was used in all patients. And neuro-ophthalmological, neuroimaging and endocrinological follow-ups were conducted postoperatively. Total (n = 95, 68. 3%), subtotal (n = 33, 23. 7%) and partial (n = 11, 7. 9%) removals were achieved. For Hardy-Wilson I, gross total removal was achieved (n = 16, 100%); Hardy-Wilson II (n = 35, 89. 7%), Hardy-Wilson III (n = 34, 70. 8%) and Hardy-Wilson IV (n = 10, 27. 8%). Postoperative visual acuity improved (92. 1%, 70/76) and endocrine remission was observed (59. 6%, 53/89). The postoperative complications included cerebrospinal fluid (CSF) leakage (n = 8, 5. 8%), meningitis (n = 3), sellar hematoma (n = 5) and delayed carotid artery rupture (n = 1). And the patient of hemorrhagic shock underwent emergency interventional procedures and was discharged successfully. Pure endoscopic endonasal transsphenoidal approach for removing pituitary adenoma is both safe and effective. And its efficacies may further increased through combined neuronavigation.

  3. A new system for neuronavigation and stereotactic biopsy pantograph stereotactic localization and guidance system.

    PubMed

    Abrishamkar, Saeid; Moin, Houshang; Safavi, Mohammadreza; Honarmand, Azim; Hajibabaie, Mahmood; Haghighi, Elham K; Abbasifard, Salman

    2011-07-01

    Everyday, neurosurgeons face the problem of orientation within the brain but the advent of stereotactic surgery and neuronavigation have solved this problem. Frame-based stereotactic systems (FBSS) and neuronavigation systems have their own strengths and priority and pitfalls, which were the main driving force for us to design a new system. This hybrid system comprises three main parts: main frame, monitoring system, and pantograph, which are connected to each other and to the operating table by particular attachments. For using this system, after performing CT SCAN or Magnetic Resonance Imaging (MRI) the axial view will be transferred to Liquid Cristal Display (LCD). In the operating room, the head of the patient fixes to the operating table and registration is completed by two arms of pantograph. We made a simulation operation with our system on an occipital cavernous angioma and a frontal oligodendroglioma. The software, which have been used for simulation were as follows; Poser (version-7), Catia (version 5- R18), and 3 Dimension Max (version 2008). The accuracy of this system is approximately two millimeter. The advantages of this system are: easy to use, much less expensive, and compatible with different devices, which may be needed during neurosurgical operation. For countries that do not have the opportunity to have sophisticated technology and neuronavigation system, we believe that our system is a one-stop solution.

  4. Neuronavigation-guided focused ultrasound-induced blood-brain barrier opening: A preliminary study in swine

    NASA Astrophysics Data System (ADS)

    Liu, Hao-Li; Tsai, Hong-Chieh; Lu, Yu-Jen; Wei, Kuo-Chen

    2012-11-01

    FUS-induced BBB opening is a promising technique for noninvasive and local delivery of drugs into the brain. Here we propose the novel use of a neuronavigation system to guide the FUS-induced BBB opening procedure, and investigate its feasibility in vivo in large animals. We developed an interface between the neuronavigator and FUS to allow guidance of the focal energy produced by the FUS transducer. The system was tested in 29 pigs by more than 40 sonication procedures and evaluated by MRI. Gd-DTPA concentration was quantitated in vivo by MRI R1 relaxometry and compared by ICP-OES assay. Brain histology after FUS exposure was investigated by HE and TUNEL staining. Neuronavigation could successfully guide the focal beam with comparable precision to neurosurgical stereotactic procedures (2.3 ± 0.9 mm). FUS pressure of 0.43 MPa resulted in consistent BBB-opening. Neuronavigation-guided BBB-opening increased Gd-DTPA deposition by up to 1.83 mM (140% increase). MR relaxometry demonstrated high correlation to ICP-OES measurements (r2 = 0.822), suggesting that Gd-DTPA deposition can be directly measured by imaging. Neuronavigation could provide sufficient precision for guiding FUS to temporally and locally open the BBB. Gd-DTPA deposition in the brain could be quantified by MR relaxometry, providing a potential tool for the in vivo quantification of therapeutic agents in CNS disease treatment.

  5. Visualization of the eloquent motor system by integration of MEG, functional, and anisotropic diffusion-weighted MRI in functional neuronavigation.

    PubMed

    Kamada, Kyousuke; Houkin, Kiyohiro; Takeuchi, Fumiya; Ishii, Nobuaki; Ikeda, Jun; Sawamura, Yutaka; Kuriki, Shinya; Kawaguchi, Hideaki; Iwasaki, Yoshinobu

    2003-05-01

    In this study, we visualized the eloquent motor system including the somatosensory-motor cortex and corticospinal tract on a neuronavigation system, integrating magnetoencephalography (MEG), functional magnetic resonance imaging (fMRI), and anisotropic diffusion-weighted MRI (ADWI). Four patients with brain lesions adjacent to the eloquent motor system were studied. Motor-evoked responses (MER) by finger-tapping paradigm were acquired with a 1.5-Tesla MR scanner, and somatosensory-evoked magnetic fields (SEF) by median nerve stimulation were measured with a 204-channel MEG system. In the same fMRI examination, ADWI and anatomic three-dimensional T1-weighted imaging (3-D MRI) were obtained. Activated areas of MER, estimated SEF dipoles, and the corticospinal tract on ADWI were coregistered to 3-D MRI, and the combined MR data were transferred to a neuronavigation system (functional neuronavigation). Intraoperative recording of cortical somatosensory-evoked potentials was performed for confirmation of the central sulcus. Combination of fMRI and MEG enabled firm identification of the central sulcus. Functional neuronavigation facilitated extensive tumor resection, having the advantage of sparing the motor cortex and corticospinal tract in all cases. The proposed functional neuronavigation allows neurosurgeons to perform effective and maximal resection of brain lesions, identifying and sparing eloquent cortical components and their subcortical connections. Potential clinical application of this technique is discussed.

  6. Electromagnetic-guided neuronavigation for safe placement of intraventricular catheters in pediatric neurosurgery.

    PubMed

    Hermann, Elvis J; Capelle, Hans-Holger; Tschan, Christoph A; Krauss, Joachim K

    2012-10-01

    Ventricular catheter shunt malfunction is the most common reason for shunt revision. Optimal ventricular catheter placement can be exceedingly difficult in patients with small ventricles or abnormal ventricular anatomy. Particularly in children and in premature infants with small head size, satisfactory positioning of the ventricular catheter can be a challenge. Navigation with electromagnetic tracking technology is an attractive and innovative therapeutic option. In this study, the authors demonstrate the advantages of using this technology for shunt placement in children. Twenty-six children ranging in age from 4 days to 14 years (mean 3.8 years) with hydrocephalus and difficult ventricular anatomy or slit ventricles underwent electromagnetic-guided neuronavigated intraventricular catheter placement in a total of 29 procedures. The single-coil technology allows one to use flexible instruments, in this case the ventricular catheter stylet, to be tracked at the tip. Head movement during the operative procedure is possible without loss of navigation precision. The intraoperative catheter placement documented by screenshots correlated exactly with the position on the postoperative CT scan. There was no need for repeated ventricular punctures. There were no operative complications. Postoperatively, all children had accurate shunt placement. The overall shunt failure rate in our group was 15%, including 3 shunt infections (after 1 month, 5 months, and 10 months) requiring operative revision and 1 distal shunt failure. There were no proximal shunt malfunctions during follow-up (mean 23.5 months). The electromagnetic-guided neuronavigation system enables safe and optimal catheter placement, especially in children and premature infants, alleviating the need for repeated cannulation attempts for ventricular puncture. In contrast to stereotactic techniques and conventional neuronavigation, there is no need for sharp head fixation using a Mayfield clamp. This technique may

  7. Brain surface reformatted imaging (BSRI) for intraoperative neuronavigation in brain tumor surgery.

    PubMed

    Forster, Marie-Therese; Heindl, Nadja; Hattingen, Elke; Gessler, Florian; Quick, Johanna; Seifert, Volker; Senft, Christian

    2015-02-01

    For safe resection of lesions situated in or near eloquent brain regions, determination of their spatial and functional relationship is crucial. Since functional magnetic resonance imaging and intraoperative neurophysiological mapping are not available in all neurosurgical departments, we aimed to evaluate brain surface reformatted imaging (BSRI) as an additional display mode for neuronavigation. Eight patients suffering from perirolandic tumors were preoperatively studied with MRI and navigated transcranial magnetic stimulation (nTMS). Afterwards, the MRI was automatically transformed into BSR images in neuronavigation software (Brainlab, Brainlab AG, Feldkirchen, Germany). One experienced neuroradiologist, one experienced neurosurgeon, and two residents determined hand representation areas ipsilateral to each tumor on two-dimensional (2D) MR images and on BSR images. All results were compared to results from intraoperative direct cortical mapping of the hand motor cortex and to preoperative nTMS results. Findings from nTMS and intraoperative direct cortical mapping of the hand motor cortex were congruent in all cases. Hand representation areas were correctly determined on BSR images in 81.3 % and on 2D-MR images in 93.75 % (p = 0.26). In a subgroup analysis, experienced observers showed more familiarity with BSRI than residents (96.9 vs. 84.4 % correct results, p = 0.19), with an equal error rate for 2D-MRI. The time required to define hand representation areas was significantly shorter using BSRI than using standard MRI (mean 27.4 vs. 40.4 s, p = 0.04). With BSRI, a new method for neuronavigation is now available, allowing fast and easy intraoperative localization of distinct brain regions.

  8. Optimal number of pulses as outcome measures of neuronavigated transcranial magnetic stimulation.

    PubMed

    Chang, Won Hyuk; Fried, Peter J; Saxena, Sadhvi; Jannati, Ali; Gomes-Osman, Joyce; Kim, Yun-Hee; Pascual-Leone, Alvaro

    2016-08-01

    Identify the optimal number of pulses necessary to achieve reliable measures of motor evoked potentials (MEPs) in transcranial magnetic stimulation (TMS) studies. Retrospective data was obtained from 54 healthy volunteers (30 men, mean age 61.7±13.1years) who as part of prior studies had completed three blocks of 30 consecutive TMS stimuli using neuronavigation. Data from four protocols were assessed: single-pulse TMS for measures of amplitude and latency of MEPs; paired-pulse TMS for short-interval intracortical inhibition (sICI) and intracortical facilitation (ICF); and single-pulse TMS to assess the effects of intermittent theta burst stimulation (iTBS). Two statistical methods were used: an internal consistency analysis and probability of inclusion in the 95% confidence interval (CI) around the mean MEPs amplitude. For single-pulse TMS, the minimum number of pulses needed to achieve reliable amplitude and latency MEPs measures was 21 and 23, respectively. For paired-pulse TMS, the minimum number of pulses needed to achieve reliable sICI and ICF measures was 20 and 25, respectively. Finally, the minimum number of pulses needed to achieve reliable amplitude and latency MEPs measures after iTBS was 22 and 23, respectively. This study provides guidelines regarding the minimum number of pulses needed to achieve reliable MEPs measurements in various study protocols using neuronavigated TMS. Results from this study have the potential to increase the reliability and quality of future neuronavigated TMS studies. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  9. Use of Frameless Stereotactic Neuronavigation and O-arm for Transoral Transpalatal Odontoidectomy to Treat a Very High Basilar Invagination

    PubMed Central

    Moorthy, Skanda; Raheja, Amol; Agrawal, Deepak

    2016-01-01

    Frameless stereotactic neuronavigation system has been in wide use since many years for precise localization of cranial tumors and navigation for spinal instrumentation. We present its usage in the localization of odontoid process in a very high basilar invagination for a transoral transpalatal resection of the same. We discuss the technical aspects of assembly of neuronavigation system, O-arm and Mayfield head frame on Allen spine system to achieve precise and accurate localization of high riding odontoid process through an extremely narrow operative corridor. PMID:28163511

  10. Integration of 3D 1H-magnetic resonance spectroscopy data into neuronavigation systems for tumor biopsies

    NASA Astrophysics Data System (ADS)

    Kanberoglu, Berkay; Moore, Nina Z.; Frakes, David; Karam, Lina J.; Debbins, Josef P.; Preul, Mark C.

    2013-03-01

    Many important applications in clinical medicine can benefit from the fusion of spectroscopy data with anatomical images. For example, the correlation of metabolite profiles with specific regions of interest in anatomical tumor images can be useful in characterizing and treating heterogeneous tumors that appear structurally homogeneous. Such applications can build on the correlation of data from in-vivo Proton Magnetic Resonance Spectroscopy Imaging (1HMRSI) with data from genetic and ex-vivo Nuclear Magnetic Resonance spectroscopy. To establish that correlation, tissue samples must be neurosurgically extracted from specifically identified locations with high accuracy. Toward that end, this paper presents new neuronavigation technology that enhances current clinical capabilities in the context of neurosurgical planning and execution. The proposed methods improve upon the current state-of-the-art in neuronavigation through the use of detailed three dimensional (3D) 1H-MRSI data. MRSI spectra are processed and analyzed, and specific voxels are selected based on their chemical contents. 3D neuronavigation overlays are then generated and applied to anatomical image data in the operating room. Without such technology, neurosurgeons must rely on memory and other qualitative resources alone for guidance in accessing specific MRSI-identified voxels. In contrast, MRSI-based overlays provide quantitative visual cues and location information during neurosurgery. The proposed methods enable a progressive new form of online MRSI-guided neuronavigation that we demonstrate in this study through phantom validation and clinical application.

  11. Neuronavigation-assisted single transseptal catheter implantation and shunt in patients with posthemorrhagic hydrocephalus and accentuated lateral ventricles dilatation

    PubMed Central

    Carvi Nievas, Mario N.

    2011-01-01

    Background: To assess the treatment of posthemorrhagic hydrocephalus with accentuated lateral ventricles dilatation by employing a single biventricular neuronavigation-assisted transseptal-implanted catheter with programmable valve and distal peritoneal derivation. Methods: A neuronavigation-assisted single transseptal biventricular catheter implantation with distal peritoneal shunt system was performed in 11 patients with posthemorrhagic hydrocephalus and accentuated lateral ventricles dilatations between 2001 and 2010. Patients with concomitant third ventricle dilatation were excluded. Several sequential frustrated attempts of temporary drainage occlusion on both sides confirmed the isolation of the lateral ventricles. Neuronavigation was employed to accurately establish the catheter surgical corridor (trajectory) across the lateral ventricles and throughout the septum pellucidum. The neurological and radiological outcomes were assessed at least 6 months after the procedure. Results: Catheter implantation was successfully performed in all patients. Only one catheter was found to be monoventricular on delayed computer tomography controls. Procedure-related complications (bleeding of infections) were not observed. No additional neurological deficits were found after shunt surgery. Six months after procedure, none required additional ventricular catheter implantations or shunt revisions. Radiological and clinical controls confirmed the shunt function and the improved neurological status of all patients. Conclusion: Single neuronavigation-assisted transseptal-implanted biventricular catheter is a valid option for the treatment of posthemorrhagic hydrocephalus with accentuated lateral ventricles dilatation. This technique reduces the number of catheters and minimizes the complexity and timing of the surgical procedure as well as potential infection's risks associated with the use of multiple shunting systems. PMID:21541201

  12. Percutaneous radiofrequency thermocoagulation for trigeminal neuralgia using neuronavigation-guided puncture from a mandibular angle

    PubMed Central

    Ding, Weihua; Chen, Shuping; Wang, Rong; Cai, Jun; Cheng, Yuan; Yu, Liang; Li, Qinghua; Deng, Fang; Zhu, Shengmei; Yu, Wenhua

    2016-01-01

    Abstract Percutaneous radiofrequency thermocoagulation (RFT) of the Gasserian ganglion is an effective treatment for primary trigeminal neuralgia (pTN). Currently Hartel anterior approach is the most commonly used method to access the Gasserian ganglion. However, this approach is associated with high recurrence rate and technical difficulties in certain patients with foramen ovale (FO) anatomical variations. In the present study, we assessed the feasibility of accessing the Gasserian ganglion through the FO from a mandibular angle under computed tomography (CT) and neuronavigation guidance. A total of 108 patients with TN were randomly divided into 2 groups (Group G and Group H) using a random number table. In Group H, Hartel anterior approach was used to puncture the FO; whereas in Group G, a percutaneous puncture through a mandibular angle was used to reach the FO. In both groups, procedures were guided by CT imaging and neuronavigation. The success rates, therapeutic effects, complications, and recurrence rates of the 2 groups were compared. The puncture success rates in Group H and Group G were 52/54 (96.30%) and 49/54 (90.74%), respectively (P = 0.24). The 2 procedural failures in Group H were rescued by using submandibular trajectory, and the 5 failures in Group G were successfully reapproached by Hartel method. Therapeutic effects as measured by Barrow Neurological Institute (BNI) pain scale (P = 0.03) and quality of life (QOL) scores (P = 0.04) were significantly better in Group G than those in Group H at 36 months posttreatment. Hematoma developed in 1/54 (1.85%) cases in Group H, and no cases of hematoma were observed in Group G (P = 0.33). In Group H, RFT resulted in injury to the unintended trigeminal nerve branches and motor fibers in 27/52 (51.92%) cases; in Group G, it resulted in the same type of injury in 7/49 cases (14.29%) (P < 0.01). In Group H, the 24- and 36-month recurrence rates were 12/51 (23.53%) and 20/51 (39

  13. 3D-neuronavigation in vivo through a patient's brain during a spontaneous migraine headache.

    PubMed

    DaSilva, Alexandre F; Nascimento, Thiago D; Love, Tiffany; DosSantos, Marcos F; Martikainen, Ilkka K; Cummiford, Chelsea M; DeBoer, Misty; Lucas, Sarah R; Bender, MaryCatherine A; Koeppe, Robert A; Hall, Theodore; Petty, Sean; Maslowski, Eric; Smith, Yolanda R; Zubieta, Jon-Kar

    2014-06-02

    A growing body of research, generated primarily from MRI-based studies, shows that migraine appears to occur, and possibly endure, due to the alteration of specific neural processes in the central nervous system. However, information is lacking on the molecular impact of these changes, especially on the endogenous opioid system during migraine headaches, and neuronavigation through these changes has never been done. This study aimed to investigate, using a novel 3D immersive and interactive neuronavigation (3D-IIN) approach, the endogenous µ-opioid transmission in the brain during a migraine headache attack in vivo. This is arguably one of the most central neuromechanisms associated with pain regulation, affecting multiple elements of the pain experience and analgesia. A 36 year-old female, who has been suffering with migraine for 10 years, was scanned in the typical headache (ictal) and nonheadache (interictal) migraine phases using Positron Emission Tomography (PET) with the selective radiotracer [(11)C]carfentanil, which allowed us to measure µ-opioid receptor availability in the brain (non-displaceable binding potential - µOR BPND). The short-life radiotracer was produced by a cyclotron and chemical synthesis apparatus on campus located in close proximity to the imaging facility. Both PET scans, interictal and ictal, were scheduled during separate mid-late follicular phases of the patient's menstrual cycle. During the ictal PET session her spontaneous headache attack reached severe intensity levels; progressing to nausea and vomiting at the end of the scan session. There were reductions in µOR BPND in the pain-modulatory regions of the endogenous µ-opioid system during the ictal phase, including the cingulate cortex, nucleus accumbens (NAcc), thalamus (Thal), and periaqueductal gray matter (PAG); indicating that µORs were already occupied by endogenous opioids released in response to the ongoing pain. To our knowledge, this is the first time that changes

  14. 3D-Neuronavigation In Vivo Through a Patient's Brain During a Spontaneous Migraine Headache

    PubMed Central

    DosSantos, Marcos F.; Martikainen, Ilkka K.; Cummiford, Chelsea M.; DeBoer, Misty; Lucas, Sarah R.; Bender, MaryCatherine A.; Koeppe, Robert A.; Hall, Theodore; Petty, Sean; Maslowski, Eric; Smith, Yolanda R.; Zubieta, Jon-Kar

    2014-01-01

    A growing body of research, generated primarily from MRI-based studies, shows that migraine appears to occur, and possibly endure, due to the alteration of specific neural processes in the central nervous system. However, information is lacking on the molecular impact of these changes, especially on the endogenous opioid system during migraine headaches, and neuronavigation through these changes has never been done. This study aimed to investigate, using a novel 3D immersive and interactive neuronavigation (3D-IIN) approach, the endogenous µ-opioid transmission in the brain during a migraine headache attack in vivo. This is arguably one of the most central neuromechanisms associated with pain regulation, affecting multiple elements of the pain experience and analgesia. A 36 year-old female, who has been suffering with migraine for 10 years, was scanned in the typical headache (ictal) and nonheadache (interictal) migraine phases using Positron Emission Tomography (PET) with the selective radiotracer [11C]carfentanil, which allowed us to measure µ-opioid receptor availability in the brain (non-displaceable binding potential - µOR BPND). The short-life radiotracer was produced by a cyclotron and chemical synthesis apparatus on campus located in close proximity to the imaging facility. Both PET scans, interictal and ictal, were scheduled during separate mid-late follicular phases of the patient's menstrual cycle. During the ictal PET session her spontaneous headache attack reached severe intensity levels; progressing to nausea and vomiting at the end of the scan session. There were reductions in µOR BPND in the pain-modulatory regions of the endogenous µ-opioid system during the ictal phase, including the cingulate cortex, nucleus accumbens (NAcc), thalamus (Thal), and periaqueductal gray matter (PAG); indicating that µORs were already occupied by endogenous opioids released in response to the ongoing pain. To our knowledge, this is the first time that changes in

  15. Cavernous sinus lesions biopsy with neuronavigation and tip-cut needle

    PubMed Central

    Lorenzetti, Martin; Carvalho, Herculano; Cattoni, Maria; Gonçalves-Ferreira, Antonio; Pimentel, José; Antuñes, Joao

    2014-01-01

    Background: Transoval biopsy of cavernous sinus (CS) lesions is the last non-invasive diagnostic option in those 15% of patients in whom etiology remains unclear in spite of extensive neuroradiological imaging, clinical assessment, and laboratory evaluation. However, there are no guidelines defining indications and the most appropriate technique for this procedure. Case Description: We present four patients in whom we performed X-ray and neuronavigation-assisted transoval CS biopsies using tip-cut needles. Conclusion: The technique described allows the operator to determine the optimal angle for entering the CS, avoiding the complications due to distorted anatomy, and facilitating orientation once inside the CS. It reduces both radiation exposure as well as general anesthesia duration. PMID:25593783

  16. Neuronavigation-guided endoscopy for intraventricular tumors in adult patients without hydrocephalus

    PubMed Central

    Grzywna, Ewelina

    2016-01-01

    Introduction Intraventricular endoscopic operations are usually undertaken in patients with an enlarged ventricular system that provides good access to the ventricles, proper anatomic orientation and safety of maneuvers within the ventricles. Aim The preliminary assessment of the feasibility of endoscopic procedures in cases occurring without hydrocephalus. Material and methods Eleven patients with intraventricular tumor diagnosed in neuroimaging studies were included in the study. None of these cases was accompanied by hydrocephalus. Surgery was performed with a rigid neuroendoscope using a neuronavigation system. The purpose of the operation was tumor removal or histological verification. Results The colloid cyst of the third ventricle was removed in 5 patients. In 1 patient a glial-derived tumor adjacent to the interventricular foramen was partially resected. In 1 case a tumor of the lateral ventricle was totally removed, and in another case the resection of such a tumor was partial. In 2 cases, a biopsy of the tumor of the posterior portion of the third ventricle was undertaken, while in 1 case the biopsy was abandoned due to the risk of injury of structures surrounding interventricular foramen. There were no intraoperative or postoperative complications. None of the patients developed hydrocephalus in the long-term follow-up. The results of treatment in the study group did not differ from those obtained in patients operated on with hydrocephalus. Conclusions The presence of hydrocephalus is not necessary to perform endoscopic surgery. However, in each case it should be preceded by a thorough analysis of the feasibility of the endoscopic procedure and should be supported by a neuronavigation system. PMID:27829944

  17. Resting state functional connectivity magnetic resonance imaging integrated with intraoperative neuronavigation for functional mapping after aborted awake craniotomy.

    PubMed

    Batra, Prag; Bandt, S Kathleen; Leuthardt, Eric C

    2016-01-01

    Awake craniotomy is currently the gold standard for aggressive tumor resections in eloquent cortex. However, a significant subset of patients is unable to tolerate this procedure, particularly the very young or old or those with psychiatric comorbidities, cardiopulmonary comorbidities, or obesity, among other conditions. In these cases, typical alternative procedures include biopsy alone or subtotal resection, both of which are associated with diminished surgical outcomes. Here, we report the successful use of a preoperatively obtained resting state functional connectivity magnetic resonance imaging (MRI) integrated with intraoperative neuronavigation software in order to perform functional cortical mapping in the setting of an aborted awake craniotomy due to loss of airway. Resting state functional connectivity MRI integrated with intraoperative neuronavigation software can provide an alternative option for functional cortical mapping in the setting of an aborted awake craniotomy.

  18. Neuronavigated microvascular Doppler sonography for intraoperative monitoring of blood flow velocity changes during aneurysm surgery - a feasible monitoring technique.

    PubMed

    Malinova, Vesna; von Eckardstein, Kajetan; Rohde, Veit; Mielke, Dorothee

    2015-10-01

    The intraoperative microvascular Doppler sonography (iMDS) is a well-established tool in vascular surgery for blood flow velocity (BFV) monitoring, capable of detecting vessel occlusion. However, identification of subtotal vessel compromise is more difficult, since the measured BFV may substantially vary with changing insonation angles and insonated vessel segments. To keep these parameters constant we combined neuronavigation with iMDS (niMDS). The question was if niMDS allows the detection of subtotal vessel compromise in aneurysm surgery. During surgery, the 3-dimensional reconstruction of the CT-angiography, which was obtained routinely prior to surgery, was displayed by the neuronavigational system. Prior to clipping, neuronavigation was used to define target point and trajectory, which, by coupling the neuronavigational pointer with the Doppler probe, correspond to the insonated vessel segment and the insonation angle. After clipping, for each vessel segment, the same trajectory was used for all consecutive measurements. The mean BFVs pre- and post-clipping were documented. We performed 82 BFV-measurements in 39 aneurysm surgeries. Mean deviation between pre- and post-clipping BFV values was 2.12cm/s. There was a significant correlation between the mean BFV values before and after clipping (r=0.45 [95% CI 17-66%]; p=0.002). One patient experienced new neurological deficits due to occlusion of a perforating vessel that was not insonated. The study could not answer the question if niMDS can detect BFV changes after clipping indicating vessel compromise, as no subtotal vessel occlusion occurred in the 39 operations. However, we proofed that niMDS-measured BFVs only varied minimally in uncompromised vessels pre- and post-clipping, suggesting that vessel compromises might be easily detected during aneurysm surgery. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. High-resolution three-dimensional T2-weighted sequence for neuronavigation: a new setup and clinical trial.

    PubMed

    Gralla, Jan; Guzman, Raphael; Brekenfeld, Caspar; Remonda, Luca; Kiefer, Claus

    2005-04-01

    Conventional imaging for neuronavigation is performed using high-resolution computerized tomography (CT) scanning or a T1-weighted isovoxel magnetic resonance (MR) sequence. The extension of some lesions, however, is depicted much better on T2-weighted MR images. A possible fusion process used to match low-resolution T2-weighted MR image set with a referenced CT or T1-weighted data set leads to poor resolution in the three-dimensional (3D) reconstruction and decreases accuracy, which is unacceptable for neuronavigation. The object of this work was to develop a 3D T2-weighted isovoxel sequence (3D turbo-spin echo [TSE]) for image-guided neuronavigation of the whole brain and to evaluate its clinical application. The authors performed a phantom study and a clinical trial on a newly developed T2-weighted isovoxel sequence, 3D TSE, for image-guided neuronavigation using a common 1.5-tesla MR imager (Siemens Sonata whole-body imager). The accuracy study and intraoperative image guidance were performed with the aid of the pointer-based Medtronic Stealth Station Treon. The 3D TSE data set was easily applied to the navigational setup and demonstrated a high registration accuracy during the experimental trial and during an initial prospective clinical trial in 25 patients. The sequence displayed common disposable skin fiducial markers and provided convincing delineation of lesions that appear hyperintense on T2-weighted images such as low-grade gliomas and cavernomas in its clinical application. Three-dimensional TSE imaging broadens the spectrum of navigational and intraoperative data sets, especially for lesions that appear hyperintense on T2-weighted images. The accuracy of its registration is very reliable and it enables high-resolution reconstruction in any orientation, maintaining the advantages of image-guided surgery.

  20. Easy-to-use augmented reality neuronavigation using a wireless tablet PC.

    PubMed

    Deng, Weiwei; Li, Fang; Wang, Manning; Song, Zhijian

    2014-01-01

    Augmented reality (AR) technology solves the problem of view switching in traditional image-guided neurosurgery systems by integrating computer-generated objects into the actual scene. However, the state-of-the-art AR solution using head-mounted displays has not been widely accepted in clinical applications because it causes some inconvenience for the surgeon during surgery. In this paper, we present a Tablet-AR system that transmits navigation information to a movable tablet PC via a wireless local area network and overlays this information on the tablet screen, which simultaneously displays the actual scene captured by its back-facing camera. With this system, the surgeon can directly observe the intracranial anatomical structure of the patient with the overlaid virtual projection images to guide the surgery. The alignment errors in the skull specimen study and clinical experiment were 4.6 pixels (approx. 1.6 mm) and 6 pixels (approx. 2.1 mm), respectively. The system was also used for navigation in 2 actual clinical cases of neurosurgery, which demonstrated its feasibility in a clinical application. The easy-to-use Tablet-AR system presented in this study is accurate and feasible in clinical applications and has the potential to become a routine device in AR neuronavigation.

  1. Onset Latency of Motor Evoked Potentials in Motor Cortical Mapping with Neuronavigated Transcranial Magnetic Stimulation.

    PubMed

    Kallioniemi, Elisa; Pitkänen, Minna; Säisänen, Laura; Julkunen, Petro

    2015-01-01

    Cortical motor mapping in pre-surgical applications can be performed using motor evoked potential (MEP) amplitudes evoked with neuronavigated transcranial magnetic stimulation. The MEP latency, which is a more stable parameter than the MEP amplitude, has not so far been utilized in motor mapping. The latency, however, may provide information about the stress in damaged motor pathways, e.g. compression by tumors, which cannot be observed from the MEP amplitudes. Thus, inclusion of this parameter could add valuable information to the presently used technique of MEP amplitude mapping. In this study, the functional cortical representations of first dorsal interosseous (FDI), abductor pollicis brevis (APB) and abductor digiti minimi (ADM) muscles were mapped in both hemispheres of ten healthy righthanded volunteers. The cortical muscle representations were evaluated by the area and centre of gravity (CoG) by using MEP amplitudes and latencies. As expected, the latency and amplitude CoGs were congruent and were located in the centre of the maps but in a few subjects, instead of a single centre, several loci with short latencies were observed. In conclusion, MEP latencies may be useful in distinguishing the cortical representation areas with the most direct pathways from those pathways with prolonged latencies. However, the potential of latency mapping to identify stressed motor tract connections at the subcortical level will need to be verified in future studies with patients.

  2. 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.

  3. Neuronavigated vs. conventional repetitive transcranial magnetic stimulation method for virtual lesioning on the Broca's area.

    PubMed

    Kim, Woo Jin; Min, Yu Sun; Yang, Eun Joo; Paik, Nam-Jong

    2014-01-01

    This study was undertaken to test the hypothesis that repetitive transcranial magnetic stimulation (rTMS) using a neuronavigational TMS system (nTMS) to the Broca's area would elicit greater virtual aphasia than rTMS using the conventional TMS method (cTMS). Eighteen healthy subjects underwent a randomized crossover experiment to induce virtual aphasia by targeting the Brodmann area 44 and 45 for nTMS, and F3 of international 10-20 system for cTMS. Reaction time for a picture naming task and the reaction duration for a six-digit number naming task were measured before and after each session of stimulation, and compared between the cTMS and nTMS. The stability of the coil positioning on the target was measured by depicting the variability of talairach coordinates (x, y, z) of the sampled stimulation localizations. At baseline, outcome variables were comparable between cTMS and nTMS. nTMS induced significant delays in reaction time from 944.0 ± 203.4 msec to 1304.6 ± 215.7 msec (p < 0.001) and reaction duration from 1780.5 ± 286.8 msec to 1914.9 ± 295.6 msec (p < 0.001) compared with baseline, whereas cTMS showed no significant changes (p = 0.959 and p = 0.179, respectively). The mean talairach space coordinates of nTMS demonstrated greater consistency of localization of stimulation with the target, and the error range relative to the target was narrower for the nTMS compared with the cTMS (p < 0.001). nTMS leads to more robust neuromodulation of Broca's area, resulting in delayed verbal reaction time as well as more accurate targeting of the intended stimulation location, demonstrating superiority of nTMS over cTMS for therapeutic use of rTMS in neurorehabilitation. © 2013 International Neuromodulation Society.

  4. New prototype neuronavigation system based on preoperative imaging and intraoperative freehand ultrasound: system description and validation.

    PubMed

    Mercier, Laurence; Del Maestro, Rolando F; Petrecca, Kevin; Kochanowska, Anna; Drouin, Simon; Yan, Charles X B; Janke, Andrew L; Chen, Sean Jy-Shyang; Collins, D Louis

    2011-07-01

    The aim of this report is to present IBIS (Interactive Brain Imaging System) NeuroNav, a new prototype neuronavigation system that has been developed in our research laboratory over the past decade that uses tracked intraoperative ultrasound to address surgical navigation issues related to brain shift. The unique feature of the system is its ability, when needed, to improve the initial patient-to-preoperative image alignment based on the intraoperative ultrasound data. Parts of IBIS Neuronav source code are now publicly available on-line. Four aspects of the system are characterized in this paper: the ultrasound probe calibration, the temporal calibration, the patient-to-image registration and the MRI-ultrasound registration. In order to characterize its real clinical precision and accuracy, the system was tested in a series of adult brain tumor cases. Three metrics were computed to evaluate the precision and accuracy of the ultrasound calibration. 1) Reproducibility: 1.77 mm and 1.65 mm for the bottom corners of the ultrasound image, 2) point reconstruction precision 0.62-0.90 mm: and 3) point reconstruction accuracy: 0.49-0.74 mm. The temporal calibration error was estimated to be 0.82 ms. The mean fiducial registration error (FRE) of the homologous-point-based patient-to-MRI registration for our clinical data is 4.9 ± 1.1 mm. After the skin landmark-based registration, the mean misalignment between the ultrasound and MR images in the tumor region is 6.1 ± 3.4 mm. The components and functionality of a new prototype system are described and its precision and accuracy evaluated. It was found to have an accuracy similar to other comparable systems in the literature.

  5. Frameless stereotactic functional neuronavigation combined with intraoperative magnetic resonance imaging as a strategy in highly eloquent located tumors causing epilepsy.

    PubMed

    Sommer, Bjoern; Grummich, Peter; Hamer, Hajo; Bluemcke, Ingmar; Coras, Roland; Buchfelder, Michael; Roessler, Karl

    2014-01-01

    Intractable epilepsy due to tumors located in highly eloquent brain regions is often considered surgically inaccessible because of a high risk of postoperative neurological deterioration. Intraoperative MRI and functional navigation contribute to overcome this problem. To retrospectively investigate the long-term results and impact of functional neuronavigation and 1.5-tesla intraoperative MRI on patients who underwent surgery of tumors associated with epilepsy located close to or within eloquent brain areas. Nineteen patients (9 female, 10 male, mean age 41.4 ± 13.4 years, 11 low-grade and 8 high-grade glial tumors) were evaluated preoperatively using BOLD imaging, diffusion-tensor imaging tractography and magnetoencephalography. Functional data were implemented into neuronavigation in this multimodal approach. In 14 of 19 patients (74%), complete resection was achieved, and in 5 patients significant tumor volume reduction was accomplished. Eight of 14 (57%) complete resections were achieved only by performing an intraoperative image update. Neurological deterioration was found permanently in 2 patients. After a mean follow-up of 43.8 ± 23.8 months, 15 patients (79%) became seizure free (Engel class Ia). Despite the highly eloquent location of tumors causing intractable epilepsy, our multimodal approach led to complete resection in more than two-thirds of patients with an acceptable neurological morbidity and excellent long-term seizure control.

  6. Impact of Virtual and Augmented Reality Based on Intraoperative Magnetic Resonance Imaging and Functional Neuronavigation in Glioma Surgery Involving Eloquent Areas.

    PubMed

    Sun, Guo-Chen; Wang, Fei; Chen, Xiao-Lei; Yu, Xin-Guang; Ma, Xiao-Dong; Zhou, Ding-Biao; Zhu, Ru-Yuan; Xu, Bai-Nan

    2016-12-01

    The utility of virtual and augmented reality based on functional neuronavigation and intraoperative magnetic resonance imaging (MRI) for glioma surgery has not been previously investigated. The study population consisted of 79 glioma patients and 55 control subjects. Preoperatively, the lesion and related eloquent structures were visualized by diffusion tensor tractography and blood oxygen level-dependent functional MRI. Intraoperatively, microscope-based functional neuronavigation was used to integrate the reconstructed eloquent structure and the real head and brain, which enabled safe resection of the lesion. Intraoperative MRI was used to verify brain shift during the surgical process and provided quality control during surgery. The control group underwent surgery guided by anatomic neuronavigation. Virtual and augmented reality protocols based on functional neuronavigation and intraoperative MRI provided useful information for performing tailored and optimized surgery. Complete resection was achieved in 55 of 79 (69.6%) glioma patients and 20 of 55 (36.4%) control subjects, with average resection rates of 95.2% ± 8.5% and 84.9% ± 15.7%, respectively. Both the complete resection rate and average extent of resection differed significantly between the 2 groups (P < 0.01). Postoperatively, the rate of preservation of neural functions (motor, visual field, and language) was lower in controls than in glioma patients at 2 weeks and 3 months (P < 0.01). Combining virtual and augmented reality based on functional neuronavigation and intraoperative MRI can facilitate resection of gliomas involving eloquent areas. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Clinical Use of Diffusion Tensor Image-Merged Functional Neuronavigation for Brain Tumor Surgeries: Review of Preoperative, Intraoperative, and Postoperative Data for 123 Cases

    PubMed Central

    Cho, Jin Mo; Kim, Eui Hyun; Kim, Jinna; Lee, Seung Koo; Kim, Sun Ho; Lee, Kyu Sung

    2014-01-01

    Purpose To achieve maximal safe resection during brain tumor surgery, functional image-merged neuronavigation is widely used. We retrospectively reviewed our cases in which diffusion tensor image (DTI)-merged functional neuronavigation was performed during surgery. Materials and Methods Between November 2008 and May 2010, 123 patients underwent surgery utilizing DTI-merged neuronavigation. Anatomical magnetic resonance images (MRI) were obtained preoperatively and fused with DTI of major white matter tracts, such as the corticospinal tract, optic radiation, or arcuate fasciculus. We used this fused image for functional neuronavigation during brain tumor surgery of eloquent areas. We checked the DTI images together with postoperative MRI images and evaluated the integrity of white matter tracts. Results A single white matter tract was inspected in 78 patients, and two or more white matter tracts were checked in 45 patients. Among the 123 patients, a grossly total resection was achieved in 90 patients (73.2%), subtotal resection in 29 patients (23.6%), and partial resection in 4 patients (3.3%). Postoperative neurologic outcomes, compared with preoperative function, included the following: 100 patients (81.3%) displayed improvement of neurologic symptoms or no change, 7 patients (5.7%) experienced postoperative permanent neurologic deterioration (additional or aggravated neurologic symptoms), and 16 patients (13.0%) demonstrated transient worsening. Conclusion DTI-merged functional neuronavigation could be a useful tool in brain tumor surgery for maximal safe resection. However, there are still limitations, including white matter tract shift, during surgery and in DTI itself. Further studies should be conducted to overcome these limitations. PMID:25048489

  8. How does adding anatomical landmarks as fiducial points in the point-matching registration of neuronavigation influence registration accuracy?

    PubMed

    Wang, Manning; Song, Zhijian

    2016-12-01

    Skin markers (SMs) are usually used as fiducial points in registration of neuronavigation, but the areas in which they can be adhered to are restricted, which usually results in poor distribution of the SMs and a large registration error. In this research, we studied whether the registration accuracy can be improved by adding anatomical landmarks (ALs), which are thought to have a larger localization error than SMs. A series of random SM configurations were generated, and for each SM configuration, we generated a corresponding SM-AL configuration by adding several ALs. We then compared the accuracy of the point-matching registration of the SM configurations with that of the corresponding SM-AL configurations. Experiment results indicated that adding ALs always made the mean target registration error of the whole head fall into a lower and narrower range, which meant that the registration became more accurate and more stable. In addition, adding more ALs resulted in a better performance.

  9. [Motor cortex stimulation for post-stroke pain using neuronavigation and evoked potentials: report of 3 cases].

    PubMed

    Ito, Masaki; Kuroda, Satoshi; Takano, Kazuya; Maruichi, Katsuhiko; Chiba, Yasuhiro; Morimoto, Yuji; Iwasaki, Yoshinobu

    2006-09-01

    Although motor cortex stimulation (MCS) has been accepted as an effective therapeutic option for central pain, the efficacy of MCS widely varies among previous reports. In this report, we describe our recent trial for successful MCS in 3 patients with central pain due to cerebral stroke. Medical treatments were transiently effective, but gradually became ineffective in all of the cases. During surgery, the appropriate cortical target was determined by using neuronavigation, somatosensory evoked potential (SEP), and motor evoked potential (MEP). A flat, four-plate electrode was positioned on the dura mater parallel to the motor cortex. After surgery, pain almost resolved in 2 of 3 patients and markedly improved in another. The pain relief depended on their motor function. These findings strongly suggest that both patient selection and intraoperative monitoring for targeting the motor cortex are quite important for successful MCS, although further studies were essential.

  10. Does the inferior frontal sulcus play a functional role in deception? A neuronavigated theta-burst transcranial magnetic stimulation study.

    PubMed

    Verschuere, Bruno; Schuhmann, Teresa; Sack, Alexander T

    2012-01-01

    By definition, lying involves withholding the truth. Response inhibition may therefore be the cognitive function at the heart of deception. Neuroimaging research has shown that the same brain region that is activated during response inhibition tasks, namely the inferior frontal region, is also activated during deception paradigms. This led to the hypothesis that the inferior frontal region is the neural substrate critically involved in withholding the truth. In the present study, we critically examine the functional necessity of the inferior frontal region in withholding the truth during deception. We experimentally manipulated the neural activity level in right inferior frontal sulcus (IFS) by means of neuronavigated continuous theta-burst stimulation (cTBS). Individual structural magnetic resonance brain images (MRI) were used to allow precise stimulation in each participant. Twenty-six participants answered autobiographical questions truthfully or deceptively before and after sham and real cTBS. Deception was reliably associated with more errors, longer and more variable response times than truth telling. Despite the potential role of IFS in deception as suggested by neuroimaging data, the cTBS-induced disruption of right IFS did not affect response times or error rates, when compared to sham stimulation. The present findings do not support the hypothesis that the right IFS is critically involved in deception.

  11. Neuronavigation without rigid pin fixation of the head in left frontotemporal tumor surgery with intraoperative speech mapping.

    PubMed

    Suess, Olaf; Picht, Thomas; Kuehn, Bjoern; Mularski, Sven; Brock, Mario; Kombos, Theodoros

    2007-04-01

    Intraoperative speech mapping has evolved into the "gold standard" for neurosurgical removal of lesions near the language cortex. The integration of neuronavigation into a multimodal protocol can improve the reliability of this type of operation, but most systems require rigid fixation of the patient's head throughout the operation. This article describes and evaluates a new noninvasively attached sensor-based reference tool, which can replace rigid pin fixation of the patient's head during awake craniotomies. The attachment technique and the resulting application accuracy were investigated under clinical conditions in 13 patients undergoing awake craniotomy with intraoperative mapping of cortical language sites. Spatial information was used for updating the image guidance by continuously adjusting the image planes relative to the position of the patient's head. The mean registration error achieved with this technique was 1.53 +/- 0.51 mm (fiducial registration error +/- standard deviation). The system's median application accuracy between dura opening and closure ranged from 0.83 to 1.85 mm (position error). The use of a reference sensor can replace uncomfortable pin fixation of the patient's head during navigation-supported awake craniotomies. Application accuracy is not affected by repositioning of the patient or by unavoidable head movements. Thus, this technique enables full exploitation of the benefits of navigation in a multimodal operative protocol without the need to rigidly fix the patient's head.

  12. Concordance Between BeamF3 and MRI-neuronavigated Target Sites for Repetitive Transcranial Magnetic Stimulation of the Left Dorsolateral Prefrontal Cortex

    PubMed Central

    Mir-Moghtadaei, Arsalan; Caballero, Ruth; Fried, Peter; Fox, Michael D.; Lee, Katherine; Giacobbe, Peter; Daskalakis, Zafiris J.; Blumberger, Daniel M.; Downar, Jonathan

    2016-01-01

    Background The dorsolateral prefrontal cortex (DLPFC) is a common target for repetitive transcranial magnetic stimulation (rTMS) in major depression, but the conventional “5 cm rule” misses DLPFC in > 1/3 cases. Another heuristic, BeamF3, locates the F3 EEG site from scalp measurements. MRI-guided neuronavigation is more onerous, but can target a specific DLPFC stereotaxic coordinate directly. The concordance between these two approaches has not previously been assessed. Objective To quantify the discrepancy in scalp site between BeamF3 versus MRI-guided neuronavigation for left DLPFC. Methods Using 100 pre-treatment MRIs from subjects undergoing left DLPFC-rTMS, we localized the scalp site at minimum Euclidean distance from a target MNI coordinate (X − 38 Y + 44 Z + 26) derived from our previous work. We performed nasion-inion, tragus–tragus, and head-circumference measurements on the same subjects’ MRIs, and applied the BeamF3 heuristic. We then compared the distance between BeamF3 and MRI-guided scalp sites. Results BeamF3-to-MRI-guided discrepancies were <0.65 cm in 50% of subjects, <0.99 cm in 75% of subjects, and <1.36 cm in 95% of subjects. The angle from midline to the scalp site did not differ significantly using MRI-guided versus BeamF3 methods. However, the length of the radial arc from vertex to target site was slightly but significantly longer (mean 0.35 cm) with MRI-guidance versus BeamF3. Conclusions The BeamF3 heuristic may provide a reasonable approximation to MRI-guided neuronavigation for locating left DLPFC in a majority of subjects. A minor optimization of the heuristic may yield additional concordance. PMID:26115776

  13. Cranial neuronavigation with direct integration of (11)C methionine positron emission tomography (PET) data -- results of a pilot study in 32 surgical cases.

    PubMed

    Braun, V; Dempf, S; Weller, R; Reske, S-N; Schachenmayr, W; Richter, H P

    2002-08-01

    MRI detects small intracranial lesions, but has difficulties in differentiating between tumour, gliosis and edema. (11)C methionine-PET may help to overcome this problem. For its appropriate intra-operative use, it must be integrated into neuronavigation. We present the results of our pilot study with this method. 32 patients with 34 intracranial lesions detected by MRI underwent additional (11)C methionine-PET, because the pathophysiological behaviour or the tumour delineation was unclear. All lesions were treated surgically. In 25 patients PET data could be integrated directly into cranial neuronavigation. (11)C methionine uptake was observed in 27/34 lesions, 26 of them were tumours: 14 malignant and 7 benign gliomas, 3 gliomas without further histological typing, one Ewing sarcoma and one non-Hodgkin lymphoma. Only one (11)C methionine positive lesion was non-tumourous: it was staged as post-irradiation necrosis in a patient operated on for a malignant glioma. 3/7 (11)C-methionine negative lesions were classified as gliosis (n=2) and M. Whipple (n=1), but 4/7 were tumours: 2 astrocytomas WHO(degrees)II, 1 DNT and one astrocytoma WHO(degrees)III. The sensitivity of (11)C methionine-PET was 87%, the specificity 75%, the positive predictive value 96% and the negative predictive value 43%. In all tumourous cases with positive tracer uptake the borderline area of the tumour was better defined by (11)C methionine-PET than by MRI. A positive (11)C methionine-PET is highly suspicious of a tumour, a negative one does not exclude it. (11)C methionine-PET seems to be more sensitive than MRI for differentiating between tumour and edema or gliosis. Simultaneous integration MRI and (11)C methionine-PET into cranial neuronavigation can facilitate cross total tumour removal in glioma surgery.

  14. 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.

  15. [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.

  16. [Intraoperative high-field magnetic resonance imaging combined with functional neuronavigation in resection of low-grade temporal lobe tumors involving optic radiation].

    PubMed

    Bai, Shaocong; Chen, Xiaolei; Geng, Jiefeng; Wu, Dongdong; Yu, Xinguang; Xu, Bainan

    2015-05-01

    To investigate the clinical value of high-field-strength intraoperative magnetic resonance imaging (iMRI) combined with optic radiation neuro-navigation for the resection of temporal lobe low-grade gliomas. From April 2009 to September 2013, 65 patients with temporal lobe low-grade gliomas (WHO grade II) involving optic radiation were operated with iMRI and functional neuro-navigation. Diffusion tensor imaging (DTI) based fiber tracking was used to delineate optic radiation. The reconstructed optic radiations were integrated into a navigation system, in order to achieve intraoperative microscopic-based functional neuro-navigation. iMRI was used to update the images for both optic radiations and residual tumors. Volumetric analyses were performed using 3D Slicer for pre- and intra-operative tumor volumes in all cases. All patients were evaluated for visual field deficits preoperatively and postoperatively. The Student t test was used to evaluate the average rate of extent of resection between groups. Spearman rank correlation analysis was used to assess correlations between predictors and epilepsy prognosis. Preoperative tumor volumes were (78±40) cm3. In 29 cases, iMRI scan detected residual tumor that could be further resected, and extent of resection were increased from 76.2% to 92.7% (t=7.314, P<0.01). In 19 cases (29.2%), gross total resection was accomplished, and iMRI contributed directly to 8 of these cases. Postsurgical follow-up period varied from 13 months to 59 months, mean (33±13) months. Tumor progression were observed in 3 patients, newly developed or deteriorated visual field defects occurred in 4 patients (6.2%). For patients with pre-operative seizures, Engel Class I were achieved for 89.7% of them. Spearman rank correlation analysis revealed that seizure outcome (Engel Class) was related to increased excision of ratio (r=-0.452, P=0.004, 95% CI: -0.636--0.261) and larger tumors (r=0.391, P=0.014, 95% CI: 0.178-0.484). With iMRI and functional

  17. 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.

  18. 3D intra-operative ultrasound and MR image guidance: pursuing an ultrasound-based management of brainshift to enhance neuronavigation.

    PubMed

    Riva, Marco; Hennersperger, Christoph; Milletari, Fausto; Katouzian, Amin; Pessina, Federico; Gutierrez-Becker, Benjamin; Castellano, Antonella; Navab, Nassir; Bello, Lorenzo

    2017-04-08

    Brainshift is still a major issue in neuronavigation. Incorporating intra-operative ultrasound (iUS) with advanced registration algorithms within the surgical workflow is regarded as a promising approach for a better understanding and management of brainshift. This work is intended to (1) provide three-dimensional (3D) ultrasound reconstructions specifically for brain imaging in order to detect brainshift observed intra-operatively, (2) evaluate a novel iterative intra-operative ultrasound-based deformation correction framework, and (3) validate the performance of the proposed image-registration-based deformation estimation in a clinical environment. Eight patients with brain tumors undergoing surgical resection are enrolled in this study. For each patient, a 3D freehand iUS system is employed in combination with an intra-operative navigation (iNav) system, and intra-operative ultrasound data are acquired at three timepoints during surgery. On this foundation, we present a novel resolution-preserving 3D ultrasound reconstruction, as well as a framework to detect brainshift through iterative registration of iUS images. To validate the system, the target registration error (TRE) is evaluated for each patient, and both rigid and elastic registration algorithms are analyzed. The mean TRE based on 3D-iUS improves significantly using the proposed brainshift compensation compared to neuronavigation (iNav) before (2.7 vs. 5.9 mm; [Formula: see text]) and after dural opening (4.2 vs. 6.2 mm, [Formula: see text]), but not after resection (6.7 vs. 7.5 mm; [Formula: see text]). iUS depicts a significant ([Formula: see text]) dynamic spatial brainshift throughout the three timepoints. Accuracy of registration can be improved through rigid and elastic registrations by 29.2 and 33.3%, respectively, after dural opening, and by 5.2 and 0.4%, after resection. 3D-iUS systems can improve the detection of brainshift and significantly increase the accuracy of the navigation in a real

  19. Neuronavigation Increases the Physiologic and Behavioral Effects of Low-Frequency rTMS of Primary Motor Cortex in Healthy Subjects

    PubMed Central

    Bashir, S.; Edwards, D.

    2013-01-01

    Low-frequency repetitive transcranial magnetic stimulation (rTMS) can exert local and inter-hemispheric neuromodulatory effects on cortical excitability. These physiologic effects can translate into changes in motor behavior, and may offer valuable therapeutic interventions in recovery from stroke. Neuronavigated TMS can maximize accurate and consistent targeting of a given cortical region, but is a lot more involved that conventional TMS. We aimed to assess whether neuronavigation enhances the physiologic and behavioral effects of low-frequency rTMS. Ten healthy subjects underwent two experimental sessions during which they received 1600 pulses of either navigated or non-navigated 1 Hz rTMS at 90% of the resting motor threshold (RMT) intensity over the motor cortical representation for left first dorsal interosseous (FDI) muscle. We compared the effects of navigated and non-navigated rTMS on motor-evoked potentials (MEPs) to single-pulse TMS, intracortical inhibition (ICI) and intracortical facilitation (ICF) by paired-pulse TMS, and performance in various behavioral tasks (index finger tapping, simple reaction time and grip strength tasks). Following navigated rTMS, the amplitude of MEPs elicited from the contralateral (unstimulated) motor cortex was significantly increased, and was associated with an increase in ICF and a trend to decrease in ICI. In contrast, non-navigated rTMS elicited nonsignificant changes, most prominently ipsilateral to rTMS. Behaviorally, navigated rTMS significantly improved reaction time RT and pinch force with the hand ipsilateral to stimulation. Non-navigated rTMS lead to similar behavioral trends, although the effects did not reach significance. In summary, navigated rTMS leads to more robust modulation of the contralateral (unstimulated) hemisphere resulting in physiologic and behavioral effects. Our findings highlight the spatial specificity of inter-hemispheric TMS effects, illustrate the superiority of navigated rTMS for certain

  20. 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.

  1. 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.

  2. Image fusion for skull base neuronavigation. Technical note.

    PubMed

    Sure, Ulrich; Benes, Ludwig; Riegel, Thomas; Schulte, Dirk Michael; Bertalanffy, Helmut

    2002-10-01

    An automatic image fusion module (BrainLab, Munich, Germany) is used for the fusion of the magnetic resonance (MR) imaging and computed tomography (CT) data sets. The procedure of image fusion takes 5 minutes prior to surgery. The image fusion of CT and MR imaging data visualizes the skull base and tumor margins clearly. Color display of the different data sets allows the tumor and the skull base to be distinguished easily. The fused CT data in bone window mode provides useful additional information on the osseous skull base.

  3. Fiducial versus nonfiducial neuronavigation registration assessment and considerations of accuracy.

    PubMed

    Pfisterer, Wolfgang K; Papadopoulos, Stephen; Drumm, Denise A; Smith, Kris; Preul, Mark C

    2008-03-01

    For frameless stereotaxy, users can choose between anatomic landmarks (ALs) or surface fiducial markers (FMs) for their match points during registration to define an alignment of the head in the physical and radiographic image space. In this study, we sought to determine the concordance among a point-merged FM registration, a point-merged AL registration, and a combined point-merged anatomic/surface-merged (SM) registration, i.e., to determine the accuracy of registration techniques with and without FMs by examining the extent of agreement between the system-generated predicted value and physical measured values. We examined 30 volunteers treated with gamma knife surgery. The frameless stereotactic image-guidance system called the StealthStation (Medtronic Surgical Navigation Technologies, Louisville, CO) was used. Nine FMs were placed on the patient's head and four were placed on a Leksell frame rod-box, which acted as a rigid set to determine the difference in error. For each registration form, we recorded the generated measurement (GM) and the physical measurement (PM) to each of the four checkpoint FMs. Bland and Altman plot difference analyses were used to compare measurement techniques. Correlations and descriptive analyses were completed. The mean of values for GMs were 1.14 mm for FM, 2.3 mm for AL, and 0.96 mm for SM registrations. The mean errors of the checkpoints were 3.49 mm for FM, 3.96 mm for AL, and 3.33 mm for SM registrations. The correlation between GMs and PMs indicated a linear relationship for all three methods. AL registration demonstrated the greatest mean difference, followed by FM registration; SM registration had the smallest difference between GMs and PMs. Differences in the anatomic registration methods, including SM registration, compared with FM registration were within a mean +/- 1.96 (standard deviation) according to the Bland and Altman analysis. For our sample of 30 patients, all three registration methods provided comparable distances to the target tissue for surgical procedures. Users may safely choose anatomic registration as a less costly and more time-efficient registration method for frameless stereotaxy.

  4. Neuronavigated transcranial magnetic stimulation suggests that area V2 is necessary for visual awareness.

    PubMed

    Salminen-Vaparanta, Niina; Koivisto, Mika; Noreika, Valdas; Vanni, Simo; Revonsuo, Antti

    2012-06-01

    The primary visual cortex (V1) has been shown to be critical for visual awareness, but the importance of other low-level visual areas has remained unclear. To clarify the role of human cortical area V2 in visual awareness, we applied transcranial magnetic stimulation (TMS) over V2 while participants were carrying out a visual discrimination task and rating their subjective awareness. Individual retinotopic maps and modelling of the TMS-induced electric field in V1, V2 and V3d ensured that the electric field was at or under the phosphene threshold level in V1 and V3d, whereas in V2 it was at the higher suppressive level. As earlier shown for the V1, our results imply that also V2 is necessary for conscious visual experience. Visual awareness of stimulus presence was completely suppressed when the TMS pulse was delivered 44-84 ms after the onset of visual stimulus. Visual discrimination and awareness of stimulus features was impaired when the TMS pulse was delivered 44-104 ms after the visual stimulus onset. These results suggest that visual awareness cannot be generated without an intact V2. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. 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.

  6. A Randomised Controlled Trial of Neuronavigated Repetitive Transcranial Magnetic Stimulation (rTMS) in Anorexia Nervosa

    PubMed Central

    McClelland, Jessica; Kekic, Maria; Bozhilova, Natali; Nestler, Steffen; Dew, Tracy; Van den Eynde, Frederique; David, Anthony S.; Rubia, Katya; Campbell, Iain C.; Schmidt, Ulrike

    2016-01-01

    Background Anorexia nervosa (AN) is associated with morbid fear of fatness, extreme food restriction and altered self-regulation. Neuroimaging data implicate fronto-striatal circuitry, including the dorsolateral prefrontal cortex (DLPFC). Methods In this double-blind parallel group study, we investigated the effects of one session of sham-controlled high-frequency repetitive transcranial magnetic stimulation (rTMS) to the left DLPFC (l-DLPFC) in 60 individuals with AN. A food exposure task was administered before and after the procedure to elicit AN-related symptoms. Outcomes The primary outcome measure was ‘core AN symptoms’, a variable which combined several subjective AN-related experiences. The effects of rTMS on other measures of psychopathology (e.g. mood), temporal discounting (TD; intertemporal choice behaviour) and on salivary cortisol concentrations were also investigated. Safety, tolerability and acceptability were assessed. Results Fourty-nine participants completed the study. Whilst there were no interaction effects of rTMS on core AN symptoms, there was a trend for group differences (p = 0.056): after controlling for pre-rTMS scores, individuals who received real rTMS had reduced symptoms post-rTMS and at 24-hour follow-up, relative to those who received sham stimulation. Other psychopathology was not altered differentially following real/sham rTMS. In relation to TD, there was an interaction trend (p = 0.060): real versus sham rTMS resulted in reduced rates of TD (more reflective choice behaviour). Salivary cortisol concentrations were unchanged by stimulation. rTMS was safe, well–tolerated and was considered an acceptable intervention. Conclusions This study provides modest evidence that rTMS to the l-DLPFC transiently reduces core symptoms of AN and encourages prudent decision making. Importantly, individuals with AN considered rTMS to be a viable treatment option. These findings require replication in multiple-session studies to evaluate therapeutic efficacy. Trial Registration www.Controlled-Trials.com ISRCTN22851337 PMID:27008620

  7. Neuronavigated Fiber Dissection with Pial Preservation: Laboratory Model to Simulate Opercular Approaches to Insular Tumors.

    PubMed

    Mandonnet, Emmanuel; Martino, Juan; Sarubbo, Silvio; Corrivetti, Francesco; Bouazza, Schahrazed; Bresson, Damien; Duffau, Hugues; Froelich, Sebastien

    2017-02-01

    Advances in the oncologic and functional results of insular surgery have been reported recently. Such successes have been made possible by the advent of the transopercular approach under awake monitoring and by improved anatomic and functional knowledge of white matter pathways surrounding the insula. Nonetheless, given the rarity of insular tumors, it is difficult to get familiar with the complex 3-dimensional anatomy of the different neuronal and vascular structures encountered during a transopercular insular resection. We thus propose to develop a laboratory model allowing to train transopercular approaches of the insula. Two hemispheres prepared with Klinger's technique were dissected under light microscope, preserving all pial membranes. The different steps of the dissection were video recorded. Preservation of pial membranes enabled us to simulate subpial resection, both during operculum removal and during insular cortex resection. The medial wall of the resection was defined by the inferior-fronto-occipital fasciculus, protecting from the lenticulostriate arteries. In this paper, we show that Klinger dissection with preservation of pial membranes provides a realistic model of insular surgery, allowing surgeons to learn and train on this highly specialized surgery. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. A Randomised Controlled Trial of Neuronavigated Repetitive Transcranial Magnetic Stimulation (rTMS) in Anorexia Nervosa.

    PubMed

    McClelland, Jessica; Kekic, Maria; Bozhilova, Natali; Nestler, Steffen; Dew, Tracy; Van den Eynde, Frederique; David, Anthony S; Rubia, Katya; Campbell, Iain C; Schmidt, Ulrike

    2016-01-01

    Anorexia nervosa (AN) is associated with morbid fear of fatness, extreme food restriction and altered self-regulation. Neuroimaging data implicate fronto-striatal circuitry, including the dorsolateral prefrontal cortex (DLPFC). In this double-blind parallel group study, we investigated the effects of one session of sham-controlled high-frequency repetitive transcranial magnetic stimulation (rTMS) to the left DLPFC (l-DLPFC) in 60 individuals with AN. A food exposure task was administered before and after the procedure to elicit AN-related symptoms. The primary outcome measure was 'core AN symptoms', a variable which combined several subjective AN-related experiences. The effects of rTMS on other measures of psychopathology (e.g. mood), temporal discounting (TD; intertemporal choice behaviour) and on salivary cortisol concentrations were also investigated. Safety, tolerability and acceptability were assessed. Fourty-nine participants completed the study. Whilst there were no interaction effects of rTMS on core AN symptoms, there was a trend for group differences (p = 0.056): after controlling for pre-rTMS scores, individuals who received real rTMS had reduced symptoms post-rTMS and at 24-hour follow-up, relative to those who received sham stimulation. Other psychopathology was not altered differentially following real/sham rTMS. In relation to TD, there was an interaction trend (p = 0.060): real versus sham rTMS resulted in reduced rates of TD (more reflective choice behaviour). Salivary cortisol concentrations were unchanged by stimulation. rTMS was safe, well-tolerated and was considered an acceptable intervention. This study provides modest evidence that rTMS to the l-DLPFC transiently reduces core symptoms of AN and encourages prudent decision making. Importantly, individuals with AN considered rTMS to be a viable treatment option. These findings require replication in multiple-session studies to evaluate therapeutic efficacy. www.Controlled-Trials.com ISRCTN22851337.

  9. Surface-based facial scan registration in neuronavigation procedures: a clinical study.

    PubMed

    Shamir, Reuben R; Freiman, Moti; Joskowicz, Leo; Spektor, Sergey; Shoshan, Yigal

    2009-12-01

    Surface-based registration (SBR) with facial surface scans has been proposed as an alternative for the commonly used fiducial-based registration in image-guided neurosurgery. Recent studies comparing the accuracy of SBR and fiducial-based registration have been based on a few targets located on the head surface rather than inside the brain and have yielded contradictory conclusions. Moreover, no visual feedback is provided with either method to inform the surgeon about the estimated target registration error (TRE) at various target locations. The goals in the present study were: 1) to quantify the SBR error in a clinical setup, 2) to estimate the targeting error for many target locations inside the brain, and 3) to create a map of the estimated TRE values superimposed on a patient's head image. The authors randomly selected 12 patients (8 supine and 4 in a lateral position) who underwent neurosurgery with a commercial navigation system. Intraoperatively, scans of the patients' faces were acquired using a fast 3D surface scanner and aligned with their preoperative MR or CT head image. In the laboratory, the SBR accuracy was measured on the facial zone and estimated at various intracranial target locations. Contours related to different TREs were superimposed on the patient's head image and informed the surgeon about the expected anisotropic error distribution. The mean surface registration error in the face zone was 0.9 +/- 0.35 mm. The mean estimated TREs for targets located 60, 105, and 150 mm from the facial surface were 2.0, 3.2, and 4.5 mm, respectively. There was no difference in the estimated TRE between the lateral and supine positions. The entire registration procedure, including positioning of the scanner, surface data acquisition, and the registration computation usually required < 5 minutes. Surface-based registration accuracy is better in the face and frontal zones, and error increases as the target location lies further from the face. Visualization of the anisotropic TRE distribution may help the surgeon to make clinical decisions. The observed and estimated accuracies and the intraoperative registration time show that SBR using the fast surface scanner is practical and feasible in a clinical setup.

  10. Improving neuronavigation through workflow and sound feedback and interactive brainshift correction

    NASA Astrophysics Data System (ADS)

    Noordmans, H. J.; Woerdeman, P. A.; Voormolen, E. H. J.; van der Steen, S.; van Stralen, M.

    2011-07-01

    In neurosurgery, navigation is being used to improve surgical orientation by using preoperative images as a roadmap. Skin or bone fiducials couple the image coordinate system to that of the patient's head fixed by the Mayfield clamp. Then the tip of a pointer of another instrument (localization device) can be seen in relation to the image to give the surgeon insight where he/she is in the brain and where the tumor or lesion can be expected in the depth. Drawbacks from current navigation systems are that 1) they only show the actual position of the localization device and thus do not hint whether the surgeon has removed the tumor completely, 2) don't warn when the device is about to hit a critical brain structure, and 3) do not compensate for shifts of the brain during surgery invalidating the pre-operative image data. During the last 5 years we investigated in our hospital whether sound and workflow feedback could improve the surgical resection accuracy and looked how the pre-operative image data could be deformed in real-time using GPU hardware to match the tracked cortical surface to compensate for brain shifts.

  11. 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.

  12. Automatic and intentional number processing both rely on intact right parietal cortex: a combined FMRI and neuronavigated TMS study.

    PubMed

    Cohen Kadosh, Roi; Bien, Nina; Sack, Alexander T

    2012-01-01

    Practice and training usually lead to performance increase in a given task. In addition, a shift from intentional toward more automatic processing mechanisms is often observed. It is currently debated whether automatic and intentional processing is subserved by the same or by different mechanism(s), and whether the same or different regions in the brain are recruited. Previous correlational evidence provided by behavioral, neuroimaging, modeling, and neuropsychological studies addressing this question yielded conflicting results. Here we used transcranial magnetic stimulation (TMS) to compare the causal influence of disrupting either left or right parietal cortex during automatic and intentional numerical processing, as reflected by the size congruity effect and the numerical distance effect, respectively. We found a functional hemispheric asymmetry within parietal cortex with only the TMS-induced right parietal disruption impairing both automatic and intentional numerical processing. In contrast, disrupting the left parietal lobe with TMS, or applying sham stimulation, did not affect performance during automatic or intentional numerical processing. The current results provide causal evidence for the functional relevance of right, but not left, parietal cortex for intentional, and automatic numerical processing, implying that at least within the parietal cortices, automatic, and intentional numerical processing rely on the same underlying hemispheric lateralization.

  13. Anatomical study of endoscope-assisted far lateral keyhole approach to the ventral craniocervical region with neuronavigational guidance.

    PubMed

    Guan, Min-wu; Wang, Jia-yin; Feng, Dong-xia; Fu, Paul; Chen, Li-hua; Li, Ming-chu; Zhang, Qiu-hang; Samii, Amir; Samii, Madjid; Kong, Feng; Zhang, Zhi-ping; Chen, Ling

    2013-01-01

    Image-guided neurosurgery, endoscopic-assisted neurosurgery and the keyhole approach are three important parts of minimally invasive neurosurgery and have played a significant role in treating skull base lesions. This study aimed to investigate the potential usefulness of coupling of the endoscope with the far lateral keyhole approach and image guidance at the ventral craniocervical junction in a cadaver model. We simulated far lateral keyhole approach bilaterally in five cadaveric head specimens (10 cranial hemispheres). Computed tomography-based image guidance was used for intraoperative navigation and for quantitative measurements. Skull base structures were observed using both an operating microscope and a rigid endoscope. The jugular tubercle and one-third of the occipital condyle were then drilled, and all specimens were observed under the microscope again. We measured and compared the exposure of the petroclivus area provided by the endoscope and by the operating microscope. Statistical analysis was performed by analysis of variance followed by the Student-Newman-Keuls test. With endoscope assistance and image guidance, it was possible to observe the deep ventral craniocervical junction structures through three nerve gaps (among facial-acoustical nerves and the lower cranial nerves) and structures normally obstructed by the jugular tubercle and occipital condyle in the far lateral keyhole approach. The surgical area exposed in the petroclival region was significantly improved using the 0° endoscope (1147.80 mm(2)) compared with the operating microscope ((756.28 ± 50.73) mm(2)). The far lateral retrocondylar keyhole approach, using both 0° and 30° endoscopes, provided an exposure area ((1147.80 ± 159.57) mm(2) and (1409.94 ± 155.18) mm(2), respectively) greater than that of the far lateral transcondylar transtubercular keyhole approach ((1066.26 ± 165.06) mm(2)) (P < 0.05). With the aid of the endoscope and image guidance, it is possible to approach the ventral craniocervical junction with the far lateral keyhole approach. The use of an angled-lens endoscope can significantly improve the exposure of the petroclival region without drilling the jugular tubercle and occipital condyle.

  14. 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

  15. Integration of intraoperative and model-updated images into an industry-standard neuronavigation system: initial results

    NASA Astrophysics Data System (ADS)

    Schaewe, Timothy J.; Fan, Xiaoyao; Ji, Songbai; Hartov, Alex; Hiemenz Holton, Leslie; Roberts, David W.; Paulsen, Keith D.; Simon, David A.

    2013-03-01

    Dartmouth and Medtronic have established an academic-industrial partnership to develop, validate, and evaluate a multimodality neurosurgical image-guidance platform for brain tumor resection surgery that is capable of updating the spatial relationships between preoperative images and the current surgical field. Previous studies have shown that brain shift compensation through a modeling framework using intraoperative ultrasound and/or visible light stereovision to update preoperative MRI appears to result in improved accuracy in navigation. However, image updates have thus far only been produced retrospective to surgery in large part because of gaps in the software integration and information flow between the co-registration and tracking, image acquisition and processing, and image warping tasks which are required during a case. This paper reports the first demonstration of integration of a deformation-based image updating process for brain shift modeling with an industry-standard image guided surgery platform. Specifically, we have completed the first and most critical data transfer operation to transmit volumetric image data generated by the Dartmouth brain shift modeling process to the Medtronic StealthStation® system. StealthStation® comparison views, which allow the surgeon to verify the correspondence of the received updated image volume relative to the preoperative MRI, are presented, along with other displays of image data such as the intraoperative 3D ultrasound used to update the model. These views and data represent the first time that externally acquired and manipulated image data has been imported into the StealthStation® system through the StealthLink® portal and visualized on the StealthStation® display.

  16. The Hand Motor Hotspot is not Always Located in the Hand Knob: A Neuronavigated Transcranial Magnetic Stimulation Study.

    PubMed

    Ahdab, Rechdi; Ayache, Samar S; Brugières, Pierre; Farhat, Wassim H; Lefaucheur, Jean-Pascal

    2016-07-01

    The hand motor hot spot (hMHS) is one of the most salient parameters in transcranial magnetic stimulation (TMS) practice, notably used for targeting. It is commonly accepted that the hMHS corresponds to the hand representation within the primary motor cortex (M1). Anatomical and imaging studies locate this representation in a region of the central sulcus called the "hand knob". The aim of this study was to determine if the hMHS location corresponds to its expected location at the hand knob. Twelve healthy volunteers and eleven patients with chronic neuropathic pain of various origins, but not related to a brain lesion, were enrolled. Morphological magnetic resonance imaging of the brain was normal in all participants. Both hemispheres were studied in all participants except four (two patients and two healthy subjects). Cortical mapping of the hand motor area was conducted using a TMS-dedicated navigation system and recording motor evoked potentials (MEPs) in the contralateral first dorsal interosseous (FDI) muscle. We then determined the anatomical position of the hMHS, defined as the stimulation site providing the largest FDI-MEPs. In 45 % of hemispheres of normal subjects and 25 % of hemispheres of pain patients, the hMHS was located over the central sulcus, most frequently at the level of the hand knob. However, in the other cases, the hMHS was located outside M1, most frequently anteriorly over the precentral or middle frontal gyrus. This study shows that the hMHS does not always correspond to the hand knob and M1 location in healthy subjects or patients. Therefore, image-guided navigation is needed to improve the anatomical accuracy of TMS targeting, even for M1.

  17. The Pursuit of DLPFC: Non-neuronavigated Methods to Target the Left Dorsolateral Pre-frontal Cortex With Symmetric Bicephalic Transcranial Direct Current Stimulation (tDCS).

    PubMed

    Seibt, Ole; Brunoni, Andre R; Huang, Yu; Bikson, Marom

    2015-01-01

    The dose of transcranial direct current stimulation (tDCS) is defined by electrode montage and current, while the resulting brain current flow is more complex and varies across individuals. The left dorsolateral pre-frontal cortex (lDLPFC) is a common target in neuropsychology and neuropsychiatry applications, with varied approaches used to experimentally position electrodes on subjects. To predict brain current flow intensity and distribution using conventional symmetrical bicephalic frontal 1 × 1 electrode montages to nominally target lDLPFC in forward modeling studies. Six high-resolution Finite Element Method (FEM) models were created from five subjects of varied head size and an MNI standard. Seven electrode positioning methods, nominally targeting lDLPFC, were investigated on each head model: the EEG 10-10 including F3-F4, F5-F6, F7-8, F9-F10, the Beam F3-System, the 5-5 cm-Rule and the developed OLE-System were evaluated as electrode positioning methods for 5 × 5 cm(2) rectangular sponge-pad electrodes. Each positioning approach resulted in distinct electrode positions on the scalp and variations in brain current flow. Variability was significant, but trends across montages and between subjects were identified. Factors enhancing electric field intensity and relative targeting in lDLPFC include increased inter-electrode distance and proximity to thinner skull structures. Brain current flow can be shaped, but not focused, across frontal cortex by tDCS montages, including intensity at lDLPFC. The OLE-system balances lDLPFC targeting and reduced electric field variability, along with clinical ease-of-use. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Neuronavigational endoscopic endonasal sellar and parasellar surgery using a 2-mm-diameter lens rigid-rod endoscope: a cadaver study.

    PubMed

    Di Rocco, Federico; Oi, Shizuo; Samii, Amir; Paternó, Vincenzo; Feigl, Günther C; Lüdemann, Wolf; Samii, Madjid

    2007-04-01

    Most of the endoscopes used for endonasal transsphenoidal surgery use 4-mm diameter lenses. The applicability of a newly developed neuroendoscope with a lens diameter of only 2 mm was tested in endonasal transsphenoidal pituitary surgery. The newly developed rigid-rod neuroendoscope with a 2-mm lens and an endoscope with a 4-mm lens were coupled with a navigation system and used for this comparative study. Comparison between the views obtained with these two devices was performed in a model and in formalin-fixed cadaver heads. A pure endonasal approach was used to reach and explore the sellar and parasellar regions. The navigation system was used to locate the same position in both lenses for image comparison. The sellar and parasellar regions could be reached and explored using the new endoscope with the 2-mm lens and an oval-shaped irrigation and suction channel. The visual field appeared to be reduced compared with that of the 4-mm lens. However, this reduction was compensated by greater mobility and easier introduction and maneuvering of the instruments at the sellar level. Reduced image size and brightness were also found using the 2-mm lens compared with the 4-mm lens. These differences could be overcome by increasing the amount of light and enlarging the image but with subsequent reduction in image resolution. The small diameter of this neuroendoscope resulted in good maneuverability and maintained a fine quality of vision. Children and patients with small nostrils are good candidates for the use of such a device.

  19. Neuronavigation in endonasal pituitary and skull base surgery using an autoregistration mask without head fixation: an assessment of accuracy and practicality.

    PubMed

    McLaughlin, Nancy; Carrau, Ricardo L; Kassam, Amin B; Kelly, Daniel F

    2012-11-01

    Intraoperative navigation is an important tool used during endonasal surgery, which typically requires rigid head fixation. Herein we describe a navigational technique using an autoregistration mask without head fixation. Prospective evaluation of a surface autoregistration mask used without rigid head fixation in 12 consecutive endonasal endoscopic skull base procedures was performed with patients positioned in a horseshoe head holder. We assessed the accuracy by recording the surface registration error (SRE) and target registration error (TRE). We also noted the time required for installation and the occurrence of system failure. The system's accuracy was validated using a deep target simultaneously viewed with endoscopic. In 12 consecutive endonasal cases performed by a neurosurgeon and ENT team, pathologies included pituitary macroadenomas (9), chordoma (1), craniopharyngioma (1), and sinonasal melanoma (1). Median time required for the registration and accuracy verification was 84 seconds (interval 64 to 129 seconds). The mask stayed on the patient throughout the procedure. The mean SRE was 0.8 mm (interval 0.6 to 0.9 mm). The mean TRE was 0.9 ± 0.7 mm and 1.0 ± 0.8 mm measured respectively at the beginning and end of the case. In every case, the system was judged accurate by the surgical team using the sphenoid keel or an intrasphenoidal bony septation as a deep target for internal validation. No system failure occurred during these 12 cases. A facial surface autoregistration mask maintained in place throughout surgery without rigid head fixation allows excellent operational accuracy in endonasal pituitary and skull base surgery. This navigation system is practical, reliable, and noninvasive. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  20. EEG and neuronavigated single-pulse TMS in the study of the observation/execution matching system: are both techniques measuring the same process?

    PubMed

    Lepage, Jean-François; Saint-Amour, Dave; Théoret, Hugo

    2008-10-30

    It is now well established that the human brain is endowed with a system that matches the observation of actions with their execution. At the motor cortex level, EEG mu rhythm modulation (8-12Hz) and TMS-induced motor evoked potentials (MEPs) are two techniques commonly used to assess brain activity during action observation. While both techniques have reliably demonstrated similarities in the pattern of activity induced by action production and action observation, the relationship they bear with each other remains elusive. In the present study, we combined ongoing EEG recordings and single-pulse TMS during the execution, imagination and observation of simple hand actions. Relationship between MEPs and EEG frequency bands at the individual level was investigated. Our results replicate those obtained independently with both techniques: a significant increase in MEP amplitude and a significant attenuation of the mu rhythm during action observation, imagination and execution compared to rest. Surprisingly, we found no significant correlation between MEP amplitude and mu rhythm modulation. However, modulation in the low to midrange beta (12-18Hz) was related to MEP size during the rest and execution conditions. These results suggest that although mu rhythm and TMS-induced MEPs are sensitive to motor resonance mechanisms, they may reflect different processes taking place within the observation/execution matching system.

  1. 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.

  2. 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.

  3. 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.

  4. A Novel Approach of Navigation-Assisted Flexible Neuroendoscopy.

    PubMed

    Torres-Corzo, Jaime G; Rangel-Castilla, Leonardo; Islas-Aguilar, Mario Alberto; Vecchia, Roberto Rodríguez-Della

    2017-05-18

    Neuronavigation-assisted endoscopy is commonly used for skull base and intraventricular surgery. Flexible neuroendoscopy offers certain advantages over rigid endoscopy; however, a major disadvantage of the flexible endoscope has been easy disorientation in the flexed position. Neuronavigation-assisted flexible neuroendoscopy was not available until now. This is the first report of the use of navigation-assisted flexible neuroendoscopy in a patient with hydrocephalus. A 10-mo-old girl presented with irritability and vomiting to the emergency department and was found to have severe hydrocephalus. The patient underwent successful endoscopic third ventriculostomy and exploration of the ventricles (lateral, third, cerebral aqueduct, fourth) and basal cisterns with the flexible neuroendoscopy assisted with electromagnetic neuronavigation. As demonstrated by this initial experience, neuronavigation-assisted flexible neuroendoscopy is a feasible and safe tool, endoscopic procedures with the flexible endoscope may be possible in a safer manner. We report the first use of neuronavigation-assisted flexible neuroendoscopy to perform an ETV and exploration of the entire ventricular system. Further evaluation will be necessary to define and expand its applications in neurosurgery.

  5. Transsphenoidal approach for pituitary adenomas in patients with McCune-Albright syndrome.

    PubMed

    Dou, Wanchen; Di, Xiao; Wang, Renzhi; Zhu, Huijuan; Yao, Yong; Deng, Kan; Feng, Ming; Li, Guilin; Wei, Junji

    2013-06-01

    The feasibility of transsphenoidal approach under a guidance of neuronavigation was explored to remove pituitary adenomas for patients with McCune-Albright syndrome (MAS). From August, 2008 to July, 2010, there were 5 patients diagnosed with MAS associated with a pituitary adenoma in our department of Peking Union Medical College Hospital. All the patients underwent transsphenoidal surgery for the removal of pituitary adenomas with the assistant of neuronavigation and all the procedures went uneventfully. Four of the five patients have got cured radiologically by imaging and 3 of them have got cured based on endocrinological criteria. Transsphenoidal approach under the neuronavigational guidance is a safe and effective management for the MAS patients with pituitary adenomas.

  6. [Application of navigation system ExacTrac in radiation therapy of a female patient with disseminated pineoblastoma].

    PubMed

    2010-01-01

    Neuronavigation is a modem and perspective technique widely applied not only in neurosurgery but in radiation treatment of neurosurgical diseases as well. Radiographic control of patient and target positioning during irradiation increases accuracy and improves treatment outcomes. Application of neuronavigation significantly expands the possibilities of radiation therapy allowing irradiation of extracranial lesions, application of mask fixation for radiation treatment, and hypofractionated radiotherapy of intracranial and spinal targets. We describe 1 illustrative case of a female patient with 2 metastases of pineoblastoma located in left cerebellar hemisphere and at the level of CVII vertebra. Both lesions were irradiated in hypofractionated mode using ExacTrac XRay 6D neuronavigation system. After 7 months these foci completely resolved.

  7. Intraoperative landmarking of vascular anatomy by integration of duplex and Doppler ultrasonography in image-guided surgery. Technical note.

    PubMed

    Sure, Ulrich; Benes, Ludwig; Bozinov, Oliver; Woydt, Michael; Tirakotai, Wuttipong; Bertalanffy, Helmut

    2005-02-01

    The integration of ultrasound technology into neuronavigation systems has recently been the subject of reports by several groups. This article describes our preliminary findings with regard to the integration of data derived from intraoperative duplex (color mode) and Doppler ultrasonography into a neuronavigational data set. It was the aim of the study to investigate (1) whether the intraoperative landmarking of vessels that are outlined with ultrasound technology is possible and (2) whether such a technique might be of clinical interest for neurosurgical interventions. The video image of an ultrasound plane (Toshiba, Powervision 6000 SSA-370A, Tokyo, Japan) was integrated into our neuronavigation system (VectorVision2, BrainLab, Heimstetten, Germany). For calibration of the ultrasound plane, an instrument adapter was fixed to the ultrasound probe and then calibrated using a special, predefined calibration phantom. Accordingly, the system supported a combination of the ultrasound plane functionality with the preoperatively acquired neuronavigational data. The duplex and Doppler mode of the ultrasound system displayed the intraoperative vascular anatomy. Once a vessel was outlined during surgery, it could be landmarked by touching the navigation screen. These landmarks were integrated automatically into the neuronavigational data set and could be used to provide intraoperative image updates of the vascular anatomy. This technique was successful in 45 of 47 (95.7%) surgical interventions. Both image-guided ultrasound and duplex-guided integration of vascular anatomy into the neuronavigational data set are technically possible. In the future, this technology may provide useful intraoperative information during surgery of complex cerebral pathologies.

  8. Transfrontal Transaqueductal, Transtrigonal, and Suboccipital Infratentorial Supracerebellar Endoscopic Fenestration of Posterior Fossa Arachnoid Cysts: Three Surgical Cases.

    PubMed

    Idris, Zamzuri; Tan, Yew Chin; Kandasamy, Regunath; Ghani, Rahman Izaini; Abdullah, Jafri Malin

    2017-03-01

    Symptomatic intracranial arachnoid cysts are commonly treated using neuroendoscopy. Cysts located within the posterior fossa may present a greater surgical challenge to the neurosurgeon due to the numerous vital neurovascular structures located within this confined space. Adding neuronavigation during endoscopy helps a neurosurgeon to visualize and utilize both anterior and posterior corridors safely to access and manage these lesions. We present three symptomatic posterior fossa arachnoid cysts that were treated successfully using minimally invasive neuronavigation-guided endoscopic neurosurgery utilizing the anterior transfrontal transaqueductal, anterior transfrontal transtrigonal, and posterior suboccipital infratentorial supracerebellar approaches.

  9. 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

  10. Surgical treatment of distal anterior cerebral artery aneurysms aided by electromagnetic navigation CT angiography.

    PubMed

    Hermann, Elvis J; Petrakakis, Ioannis; Götz, Friedrich; Lütjens, Götz; Lang, Josef; Nakamura, Makoto; Krauss, Joachim K

    2015-07-01

    The surgical treatment of distal anterior cerebral artery (DACA) aneurysms still presents a challenge for neurosurgeons because of their small size and their location in the depth of the narrow frontal interhemispheric fissure. This study aimed to investigate feasibility, safety, accuracy, and usefulness of electromagnetic (EM) navigation to aid clipping of DACA aneurysms. Eight patients (age between 2 and 68 years, mean age 49.8 years) with a DACA aneurysm underwent EM-guided neuronavigated microsurgery for clipping of the aneurysm. All patients underwent craniocervical 3D-CT angiography preoperatively. After planning the optimal approach and surgical trajectory avoiding opening of the frontal sinus, the head was fixed. Intraoperative screenshots were correlated with the microscopical view of the DACA aneurysms before clipping. EM-guided neuronavigation using CT angiography for DACA aneurysms enabled fast and accurate referencing of the patient and planning of a tailored craniotomy without opening of the frontal sinus. Intraoperative accuracy was highly reliable except in one instance due to dislocation of the dynamic reference frame (DRF). There was a good correlation between the 3D-CT angiography-based navigation data sets and the intraoperative vascular anatomy. In all patients, bridging veins were spared. The aid of EM neuronavigation was considered useful in all instances. EM-guided neuronavigation using CT angiography for surgery of DACA aneurysms is a useful tool optimizing the surgical approach directly to the aneurysm minimizing additional damage to the surrounding tissue during preparation of the aneurysm and the parent vessel.

  11. THE VALUE OF PRE- AND INTRA-OPERATIVE ADJUNCTS ON THE EXTENT OF RESECTION OF HEMISPHERIC LOW GRADE GLIOMAS; A RETROSPECTIVE ANALYSIS

    PubMed Central

    Incekara, Fatih; Olubiyi, Olutayo; Ozdemir, Aysegul; Lee, Tom; Rigolo, Laura; Golby, Alexandra

    2016-01-01

    Background To achieve maximal resection with minimal risk of postoperative neurological morbidity, different neurosurgical adjuncts are being used during low grade glioma (LGG) surgery. Objectives The goal of this study was to investigate the effect of pre- and intra-operative adjuncts on the extent of resection (EOR) of hemispheric LGGs. Methods Medical records were reviewed to identify patients of any sex, 18 years or older, who underwent LGG surgery at ‘X’ Hospital between January 2005 and July 2013. Patients were divided in 8 subgroups based on the use of neuronavigation system alone (NN), functional MRI-diffusion tensor imaging (fMRI-DTI) guided neuronavigation (FD), intra-operative MRI (MR) and direct electrical stimulation (DES). Initial and residual tumors were measured and mean EOR was compared between groups. Results Of all 128 patients, gross total resection was achieved in 23.4%. Overall mean EOR was 81.3% ± 20.5%. Using DES in combination with fMRI-DTI (mean EOR 86.7% ± 12.4%) on eloquent tumors improved mean EOR significantly after adjustment for potential confounders, when compared with neuronavigation alone (mean EOR 76.4% ± 25.5%, p = 0.001). Conclusions Using DES in combination with fMRI and DTI significantly improves EOR when LGGs are located in eloquent areas, compared with craniotomies were only neuronavigation was used. PMID:26216736

  12. Re-evaluation of the role of image guidance in minimally invasive pituitary surgery: benefits and outcomes.

    PubMed

    Patel, Samip N; Youssef, A Samy; Vale, Fernando L; Padhya, Tapan A

    2011-01-01

    To evaluate the utility of performing endonasal transsphenoidal pituitary surgery with computer-based neuronavigation, and to examine the efficacy of computer-based neuronavigation compared to fluoroscopy. We conducted a retrospective review of patients who underwent pituitary surgery between September 1998 and September 2008. Of 120 consecutive patients, 70 met inclusion criteria and were fully examined. The inclusion criteria were that patients had undergone endonasal transsphenoidal pituitary surgery performed by the same neurosurgeon at the same institution. Nineteen of the patients were treated using intraoperative fluoroscopy and 48 were treated using the BrainLAB VectorVision neuronavigation system. Preparation times, surgical times and associated complications were analyzed. Our results indicate that image guidance reduces the overall operating room time and complication rate. Average preparation time for fluoroscopy and computer-based neuronavigation was 70.3 and 67.3 min, respectively (p = 0.3299). Average surgical time with fluoroscopy and BrainLAB was 131 and 107.9 min, respectively (p = 0.0079). The results were also analyzed with regard to other parameters such as associated complications, age and diagnoses. Computer guided endoscopic endonasal transsphenoidal surgery provides a three-dimensional image to the surgeon, allowing for greater visual accuracy and surgical precision and a faster procedure without radiation exposure or the need for additional personnel.

  13. [Image-guided endoscopic transsphenoidal removal of pituitary adenoma].

    PubMed

    Zhang, Qui-Hang; Liu, Hai-Sheng; Yang, Da-Zhang; Cheng, Jing-Yu

    2005-01-01

    To assess the role of neuronavigation in assisting endoscopic transsphenoidal surgery for pituitary adenomas. Ten endoscopic endonasal transsphenoidal reoperations for pituitary adenomas were selected. Clinical records were reviewed retrospectively. Five of 10 patients had gigantic adenoma, 3 microadenoma, 2 large adenoma. The mean setup time was 5 minutes, and the operative time was 50 minutes in image-guided procedures. In all cases, the system worked well without malfunction. Continuous information regarding instrument location and trajectory was provided to the surgeon. Measurements of intraoperative accuracy in the axial, coronal, and.sagittal planes indicated a mean verified system error of 1.5 mm. for pituitary adenomas. After operation, the symptoms relieved in all patients. Neuronavigation can be applied during endonasal transsphenoidal endoscopic surgery and requires a minimal amount of time. It makes reoperation easier, faster, and safer.

  14. [Development of automatic navigation measuring system using template-matching software in image guided neurosurgery].

    PubMed

    Watanabe, Yohei; Hayashi, Yuichiro; Fujii, Masazumi; Kimura, Miyuki; Sugiura, Akihiro; Tsuzaka, Masatoshi; Wakabayashi, Toshihiko

    2010-02-20

    An image-guided neurosurgery and neuronavigation system based on magnetic resonance imaging has been used as an indispensable tool for resection of brain tumors. Therefore, accuracy of the neuronavigation system, provided by periodic quality assurance (QA), is essential for image-guided neurosurgery. Two types of accuracy index, fiducial registration error (FRE) and target registration error (TRE), have been used to evaluate navigation accuracy. FRE shows navigation accuracy on points that have been registered. On the other hand, TRE shows navigation accuracy on points such as tumor, skin, and fiducial markers. This study shows that TRE is more reliable than FRE. However, calculation of TRE is a time-consuming, subjective task. Software for QA was developed to compute TRE. This software calculates TRE automatically by an image processing technique, such as automatic template matching. TRE was calculated by the software and compared with the results obtained by manual calculation. Using the software made it possible to achieve a reliable QA system.

  15. Validation of Exposure Visualization and Audible Distance Emission for Navigated Temporal Bone Drilling in Phantoms

    PubMed Central

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

    2012-01-01

    Background A neuronavigation interface with extended function as compared with current systems was developed to aid during temporal bone surgery. The interface, named EVADE, updates the prior anatomical image and visualizes the bone drilling process virtually in real-time without need for intra-operative imaging. Furthermore, EVADE continuously calculates the distance from the drill tip to segmented temporal bone critical structures (e.g. the sigmoid sinus and facial nerve) and produces audiovisual warnings if the surgeon drills in too close vicinity. The aim of this study was to evaluate the accuracy and surgical utility of EVADE in physical phantoms. Methodology/Principal Findings We performed 228 measurements assessing the position accuracy of tracking a navigated drill in the operating theatre. A mean target registration error of 1.33±0.61 mm with a maximum error of 3.04 mm was found. Five neurosurgeons each drilled two temporal bone phantoms, once using EVADE, and once using a standard neuronavigation interface. While using standard neuronavigation the surgeons damaged three modeled temporal bone critical structures. No structure was hit by surgeons utilizing EVADE. Surgeons felt better orientated and thought they had improved tumor exposure with EVADE. Furthermore, we compared the distances between surface meshes of the virtual drill cavities created by EVADE to actual drill cavities: average maximum errors of 2.54±0.49 mm and −2.70±0.48 mm were found. Conclusions/Significance These results demonstrate that EVADE gives accurate feedback which reduces risks of harming modeled critical structures compared to a standard neuronavigation interface during temporal bone phantom drilling. PMID:22848452

  16. Trigeminal Neuralgia Due to a Small Meckel's Cave Epidermoid Tumor: Surgery Using an Extradural Corridor.

    PubMed

    Furtado, Sunil V; Hegde, Alangar S

    2009-09-01

    Tumors at the petrous apex are associated with a variety of symptoms, which most often involve the trigeminal nerve. The authors present a rare case of a small epidermoid tumor in Meckel's cave that caused medically refractory trigeminal neuralgia. The surgical challenge associated with approaches to such lesions is discussed. The skull base tumor was excised completely through a small temporal craniotomy. The practicality of neuronavigation in reaching the petrous apex using a small extradural window is presented.

  17. Method for quantitative validation of image-based correction for intraoperative brain shift

    NASA Astrophysics Data System (ADS)

    Bates, Lisa M.; Goerss, Stephan J.; Robb, Richard A.

    2000-04-01

    Stereotactic neuronavigational systems use pre-operatively acquired 3D images for procedural planning and also are employed in intraoperative navigations to help localize and resect brain lesions. Intraoperatively, multiple factors contribute to anatomic changes that limit the accuracy of navigation based solely on pre-operative images. Loss of CSF, cortical swelling, and the effect of gravity relative to the craniotomy locations are some of the factors that contribute to errors in navigation.

  18. From the Idea to Its Realization: The Evolution of Minimally Invasive Techniques in Neurosurgery

    PubMed Central

    Grunert, P.

    2013-01-01

    Minimally invasive techniques in neurosurgery evolved in two steps. Many minimally invasive concepts like neuronavigation, endoscopy, or frame based stereotaxy were developed by the pioneers of neurosurgery, but it took decades till further technical developments made the realization and broad clinical application of these early ideas safe and possible. This thesis will be demonstrated by giving examples of the evolution of four minimally invasive techiques: neuronavigation, transsphenoidal pituitary surgery, neuroendoscopy and stereotaxy. The reasons for their early failure and also the crucial steps for the rediscovery of these minimally invasive techniques will be analysed. In the 80th of the 20th century endoscopy became increasingly applied in different surgical fields. The abdominal surgeons coined as first for their endoscopic procedures the term minimally invasive surgery in contrast to open surgery. In neurrosurgery the term minimally invasive surgery stood not in opposiotion to open procedures but was understood as a general concept and philosophy using the modern technology such as neuronavigation, endoscopy and planing computer workstations with the aim to make the procedures less traumatic. PMID:24455231

  19. Image-guided endoscopic transnasal removal of recurrent pituitary adenomas.

    PubMed

    Lasio, Giovanni; Ferroli, Paolo; Felisati, Giovanni; Broggi, Giovanni

    2002-07-01

    To assess the role that neuronavigation plays in assisting endoscopic transsphenoidal reoperations for recurrent pituitary adenomas. During a 45-month period, 19 endoscopic endonasal transsphenoidal reoperations were performed for recurrent pituitary adenomas. In 11 of 19 patients, the procedure was performed with the aid of an optically guided system. Clinical records were reviewed retrospectively, with attention to the following: comparison of baseline clinical data, the duration of surgery, and the postoperative course and complications of both image-guided and non-image-guided endoscopic reoperations. In addition, to test the reliability of the neuronavigation system, we made measurements of intraoperative accuracy in five additional transnasal endoscopic procedures in "virgin" noses and sphenoidal sinuses. In both groups studied, we found no difference with regard to either morbidity or mortality, which were null. The mean setup time was 13 minutes shorter in non-image-guided procedures (P = 0.021), and the operative time was 36 minutes shorter in image-guided procedures (P = 0.038). No other statistically significant differences were found between the two groups. In all cases, we found that the system performed without malfunction. Continuous information regarding instrument location and trajectory was provided to the surgeon. Measurements of the intraoperative accuracy in the axial, coronal, and sagittal planes indicated a mean intraoperatively verified system error of 1.6 +/- 0.6 mm. Neuronavigation can be applied during endonasal transsphenoidal endoscopic surgery and requires a minimal amount of time. It makes reoperation easier, faster, and probably safer.

  20. Image guided surgery for petrous apex lesions.

    PubMed

    Van Havenbergh, T; Koekelkoren, E; De Ridder, D; Van De Heyning, P; Verlooy, J

    2003-09-01

    To evaluate whether computer-assisted frameless stereotactic navigation in the temporal bone provides sufficient clinical application accuracy and thus a useful tool in temporal bone surgery. Two patients with petrous apex cholesterol granuloma were operated on by an epidural middle fossa approach using a Stealth/Medtronic trade mark neuronavigation system. Based on literature data optimal skin fiducial placement and registration methods were used. Intra-operative accuracy was checked using three precise anatomical landmarks. Drilling of the petrous apex bone was guided by neuronavigation. Postoperative Computed Tomography (CT) images were fused with the preoperative CT and planning. The application of image-guidance in temporal bone surgery causes no additional burden to the patient nor prolongs the operating time. The accuracy measured at the anatomical landmarks was under 2,0 mm. This is confirmed by evaluation of bone removal through image fusion of pre- and postoperative CT-scan. The clinical application of a neuronavigation system during petrous apex surgery can be regarded as useful. Using all available data on registration methods it seems possible to obtain intra-operative application accuracies of <2,0 mm. Additional cadaver work is being performed to support these data.

  1. Transsulcal approach supported by navigation-guided neurophysiological monitoring for resection of paracentral cavernomas.

    PubMed

    Zhou, Hongyu; Miller, Dorothea; Schulte, Dirk Michael; Benes, Ludwig; Rosenow, Felix; Bertalanffy, Helmut; Sure, Ulrich

    2009-01-01

    The aim of the study is to evaluate tools that can improve surgical precision and minimize surgical trauma for removal of cavernomas in the paracentral area. Moreover, the surgical strategies for the treatment of symptomatic epilepsy in cavernoma patients are discussed. Between June 2000 and July 2007, 17 patients suffering from paracentral cavernoma underwent surgery via a transsulcal approach with the aid of neuronavigation, functional mapping and neurophysiological intraoperative monitoring. To optimize outcome for procedures in the paracentral area, the hemosiderin-stained tissue was removed entirely except for a small proportion on the side of precentral gyrus. All cavernomas and their adjacent sulci could be precisely located with the aid of ultrasonography-assisted neuronavigation. By combining preoperative fMRI and intraoperative neurophysiological monitoring, including SEP, MEP and cortical mapping, the motor cortex could be defined in all cases. Thus damage to the primary motor area could be avoided during resection of cavernomas. All the lesions located in the paracentral area were removed completely via transsulcal microsurgical approach without neurological deficits. No significant seizures were induced during surgery. The successful excision of these lesions was effected by the following four key factors: (1) the precise location of the lesion supported by intraoperative neuronavigation; (2) the preservation of the eloquent area with the aid of functional mapping; (3) a minimally invasive transsulcal microsurgical approach; and (4) the entire removal of cavernoma and hemosiderin-stained tissue.

  2. Optimizing ventriculoperitoneal shunt placement in the treatment of idiopathic intracranial hypertension: an analysis of neuroendoscopy, frameless stereotaxy, and intraoperative CT.

    PubMed

    Yim, Benjamin; Reid Gooch, M; Dalfino, John C; Adamo, Matthew A; Kenning, Tyler J

    2016-03-01

    Cerebrospinal fluid shunting can effectively lower intracranial pressure and improve the symptoms of idiopathic intracranial hypertension (IIH). Placement of ventriculoperitoneal (VP) shunts in this patient population can often be difficult due to the small size of the ventricular system. Intraoperative adjuvant techniques can be used to improve the accuracy and safety of VP shunts for these patients. The purpose of this study was to analyze the efficacy of some of these techniques, including the use of intraoperative CT (iCT) and frameless stereotaxy, in optimizing postoperative ventricular catheter placement. The authors conducted a retrospective review of 49 patients undergoing initial ventriculoperitoneal shunt placement for the treatment of IIH. The use of the NeuroPEN Neuroendoscope, intraoperative neuronavigation, and iCT was examined. To analyze ventricular catheter placement on postoperative CT imaging, the authors developed a new grading system: Grade 1, catheter tip terminates optimally in the ipsilateral frontal horn or third ventricle; Grade 2, catheter tip terminates in the contralateral frontal horn; Grade 3, catheter terminates in a nontarget CSF space; and Grade 4, catheter tip terminates in brain parenchyma. All shunts had spontaneous CSF flow upon completion of the procedure. The average body mass index among all patients was 37.6 ± 10.9 kg/m2. The NeuroPEN Neuroendoscope was used in 44 of 49 patients. Intraoperative CT scans were obtained in 24 patients, and neuronavigation was used in 32 patients. Grade 1 or 2 final postoperative shunt placement was achieved in 90% of patients (44 of 49). In terms of achieving optimal postoperative ventricular catheter placement, the use of iCT was as effective as neuronavigation. Two patients had their ventricular catheter placement modified based on an iCT study. The use of neuronavigation significantly increased time in the operating room (223.4 ± 46.5 vs. 190.8 ± 31.7 minutes, p = 0.01). There were no

  3. Preoperative assessment of motor cortex and pyramidal tracts in central cavernoma employing functional and diffusion-weighted magnetic resonance imaging.

    PubMed

    Möller-Hartmann, Walter; Krings, Timo; Coenen, Volker A; Mayfrank, Lothar; Weidemann, Jürgen; Kränzlein, Heidi; Thron, Armin

    2002-11-01

    Functional MRI (fMRI) combines anatomic with functional information and has therefore been widely used for preoperative planning of patients with mass lesions affecting functionally important brain regions. However, the courses of functionally important fiber tracts are not visualized. We therefore propose to combine fMRI with diffusion-weighted MRI (DWI) that allows visualization of large fiber tracts and to implement this data in a neuronavigation system. DWI was successfully performed at a field strength of 1.5 Tesla, employing a spin-echo sequence with gradient sensitivity in six noncollinear directions to visualize the course of the pyramidal tracts, and was combined with echo-planar T2* fMRI during a hand motor task in a patient with central cavernoma. Fusion of both data sets allowed visualization of the displacement of both the primary sensorimotor area (M1) and its large descending fiber tracts. Intraoperatively, these data were used to aid in neuronavigation. Confirmation was obtained by intraoperative electrical stimulation. Postoperative MRI revealed an undisrupted pyramidal tract in the neurologically intact patient. The combination of fMRI with DWI allows for assessment of functionally important cortical areas and additional visualization of large fiber tracts. Information about the orientation of fiber tracts in normal appearing white matter in patients with tumors within the cortical motor system cannot be obtained by other functional or conventional imaging methods and is vital for reducing operative morbidity as the information about functional cortex. This technique might, therefore, have the prospect of guiding neurosurgical interventions, especially when linked to a neuronavigation system.

  4. The use of intraoperative computed tomography navigation in pituitary surgery promises a better intraoperative orientation in special cases

    PubMed Central

    Linsler, Stefan; Antes, Sebastian; Senger, Sebastian; Oertel, Joachim

    2016-01-01

    Objective: The safety of endoscopic skull base surgery can be enhanced by accurate navigation in preoperative computed tomography (CT) and magnetic resonance imaging (MRI). Here, we report our initial experience of real-time intraoperative CT-guided navigation surgery for pituitary tumors in childhood. Materials and Methods: We report the case of a 15-year-old girl with a huge growth hormone-secreting pituitary adenoma with supra- and perisellar extension. Furthermore, the skull base was infiltrated. In this case, we performed an endonasal transsphenoidal approach for debulking the adenoma and for chiasma decompression. We used an MRI neuronavigation (Medtronic Stealth Air System) which was registered via intraoperative CT scan (Siemens CT Somatom). Preexisting MRI studies (navigation protocol) were fused with the intraoperative CT scans to enable three-dimensional navigation based on MR and CT imaging data. Intraoperatively, we did a further CT scan for resection control. Results: The intraoperative accuracy of the neuronavigation was excellent. There was an adjustment of <1 mm. The navigation was very helpful for orientation on the destroyed skull base in the sphenoid sinus. After opening the sellar region and tumor debulking, we did a CT scan for resection control because the extent of resection was not credible evaluable in this huge infiltrating adenoma. Thereby, we were able to demonstrate a sufficient decompression of the chiasma and complete resection of the medial part of the adenoma in the intraoperative CT images. Conclusions: The use of intraoperative CT/MRI-guided neuronavigation for transsphenoidal surgery is a time-effective, safe, and technically beneficial technique for special cases. PMID:27695249

  5. Importance of intraoperative magnetic resonance imaging for pediatric brain tumor surgery.

    PubMed

    Yousaf, Jawad; Avula, Shivaram; Abernethy, Laurence J; Mallucci, Conor L

    2012-01-01

    High-field intraoperative MRI (IoMRI) is gaining increasing recognition as an invaluable tool in pediatric brain tumor surgery where the extent of tumor resection is a major prognostic factor. We report the initial experience of a dedicated pediatric 3-T intraoperative MRI (IoMRI) unit with integrated neuronavigation in the management of pediatric brain tumors. Seventy-three children (mean age 9.5 years; range 0.2-19 years) underwent IoMRI between October 2009 and January 2012, during 79 brain tumor resections using a 3-T MR scanner located adjacent to the neurosurgical operating theater that is equipped with neuronavigation facility. IoMRI was performed either to assess the extent of tumor resection after surgical impression of complete/intended tumor resection or to update neuronavigation. The surgical aims, IoMRI findings, extent of tumor resection, and follow-up data were reviewed. Complete resection was intended in 47/79 (59%) operations. IoMRI confirmed complete resection in 27/47 (57%). IoMRI findings led to further resection in 12/47 (26%). In 7/47 (15%), IoMRI was equivocal for residual tumor and no evidence of residual tumor was found on re-inspection. In 32/79 (41%) operations, the surgical aim was partial tumor resection. In this subset, surgical resection was extended following IoMRI in 13/32 (41%) operations. None of the patients required early second look procedure for residual disease. At our institution, IoMRI has led to increased rate of tumor resection and a change in surgical strategy with further tumor resection in 32% of patients. While interpreting IoMRI, it is important to be aware of the known pitfalls.

  6. The use of intraoperative computed tomography navigation in pituitary surgery promises a better intraoperative orientation in special cases.

    PubMed

    Linsler, Stefan; Antes, Sebastian; Senger, Sebastian; Oertel, Joachim

    2016-01-01

    The safety of endoscopic skull base surgery can be enhanced by accurate navigation in preoperative computed tomography (CT) and magnetic resonance imaging (MRI). Here, we report our initial experience of real-time intraoperative CT-guided navigation surgery for pituitary tumors in childhood. We report the case of a 15-year-old girl with a huge growth hormone-secreting pituitary adenoma with supra- and perisellar extension. Furthermore, the skull base was infiltrated. In this case, we performed an endonasal transsphenoidal approach for debulking the adenoma and for chiasma decompression. We used an MRI neuronavigation (Medtronic Stealth Air System) which was registered via intraoperative CT scan (Siemens CT Somatom). Preexisting MRI studies (navigation protocol) were fused with the intraoperative CT scans to enable three-dimensional navigation based on MR and CT imaging data. Intraoperatively, we did a further CT scan for resection control. The intraoperative accuracy of the neuronavigation was excellent. There was an adjustment of <1 mm. The navigation was very helpful for orientation on the destroyed skull base in the sphenoid sinus. After opening the sellar region and tumor debulking, we did a CT scan for resection control because the extent of resection was not credible evaluable in this huge infiltrating adenoma. Thereby, we were able to demonstrate a sufficient decompression of the chiasma and complete resection of the medial part of the adenoma in the intraoperative CT images. The use of intraoperative CT/MRI-guided neuronavigation for transsphenoidal surgery is a time-effective, safe, and technically beneficial technique for special cases.

  7. Intraventricular meningiomas: a report of 16 cases.

    PubMed

    Bertalanffy, Alexander; Roessler, Karl; Koperek, Oskar; Gelpi, Ellen; Prayer, Daniela; Neuner, Markus; Knosp, Engelbert

    2006-01-01

    Meningiomas of the ventricle system are extremely rare. We report on a series of 16 intraventricular meningiomas (IVMs) treated at our institution between 1980 and 2004, with a special interest on the surgical outcome of using the intra/inter-parietal and parieto-occipital approach and the benefits of neuro-navigation. A retrospective analysis of the medical files for clinicoradiological findings, surgical interventions and surgical outcome was carried out. In 16 IVM patients with a female/male ratio of 11:5, age ranged from 24 years to 84 years (median 44 years). Duration of symptoms ranged from a few days to several years, and the cardinal symptoms were signs of increased intracranial pressure (86%), followed by corticospinal tract signs (43%), visual field defects (36%), cognitive changes (29%) and seizures (7%). The majority of tumours was located in the trigone (88%), and one was found in each the temporal horn and in the fourth ventricle. Tumour size ranged from 2.5 cm to 8 cm (median 5 cm), and the radiological appearance was uniform. The neuropathological workup revealed most IVMs as meningothelial, transitional (mixed) or lymphoplasmacyte-rich meningiomas (81%). Three tumours were classified as atypical (19%) and the MIB-1 proliferation index ranged from 1% to 40%. Complete resection was possible in all but one case. The trigonal IVMs were resected via an intraparietal/inter-parietal or parieto-occipital approach, and neuro-navigation was used in eight tumours. We encountered one perioperative death and one severely disabled patient. All other patients had a Glasgow outcome scale score of 5, and most of the pre-existing symptoms disappeared or improved after surgery. IVMs are a surgically curable tumour entity in most cases. The intraparietal/inter-parietal and parieto-occipital approach is very safe, and neuro-navigation allows early devascularisation of the tumour.

  8. Transcranial brain stimulation: clinical applications and future directions.

    PubMed

    Najib, Umer; Bashir, Shahid; Edwards, Dylan; Rotenberg, Alexander; Pascual-Leone, Alvaro

    2011-04-01

    Noninvasive brain stimulation is a valuable investigative tool and has potential therapeutic applications in cognitive neuroscience, neurophysiology, psychiatry, and neurology. Transcranial magnetic stimulation (TMS) is particularly useful to establish and map causal brain-behavior relations in motor and nonmotor cortical areas. Neuronavigated TMS is able to provide precise information related to the individual's functional anatomy that can be visualized and used during surgical interventions and critically aid in presurgical planning, reducing the need for riskier and more cumbersome intraoperative or invasive mapping procedures. This article reviews methodological aspects, clinical applications, and future directions of TMS-based mapping.

  9. 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.

  10. Cortical mapping and frameless stereotactic navigation in the high-field intraoperative magnetic resonance imaging suite

    PubMed Central

    Weingarten, David M.; Asthagiri, Ashok R.; Butman, John A.; Sato, Susumu; Wiggs, Edythe A.; Damaska, Bonita; Heiss, John D.

    2013-01-01

    Frameless stereotactic neuronavigation provides tracking of surgical instruments on radiographic images and orients the surgeon to tumor margins at surgery. Bipolar electrical stimulation mapping (ESM) delineates safe limits for resection of brain tumors adjacent to eloquent cortex. These standard techniques could complement the capability of intraoperative MR (iMR) imaging to evaluate for occult residual disease during surgery and promote more complete tumor removal. The use of frameless neuronavigation in the high-field iMR imaging suite requires that a few pieces of standard equipment be replaced by nonferromagnetic instruments. Specific use of ESM in a high-field iMR imaging suite has not been reported in the literature. To study whether frameless neuronavigation and electrical stimulation mapping could be successfully integrated in the high-field iMR imaging suite, the authors employed these modalities in 10 consecutive cases involving patients undergoing conscious craniotomy for primary brain tumors located in or adjacent to eloquent cortices. Equipment included a custom high-field MR imaging–compatible head holder and dynamic reference frame attachment, a standard MR imaging–compatible dynamic reference frame, a standard MR imaging machine with a table top that could be translated to a pedestal outside the 5-gauss line for the operative intervention, and standard neuronavigational and cortical stimulation equipment. Both ESM and frameless stereotactic guidance were performed outside the 5-gauss line. The presence of residual neoplasm was evaluated using iMR imaging; resection was continued until eloquent areas were encountered or iMR imaging confirmed complete removal of any residual tumor. Mapping identified essential language (5 patients), sensory (6), and motor (7) areas. The combined use of frameless stereotactic navigation, ESM, and iMR imaging resulted in complete radiographic resection in 7 cases and resection to an eloquent margin in 3 cases

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

    PubMed Central

    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. PMID:26354118

  12. Minimally invasive approach to management of pituitary adenomas.

    PubMed

    Kanaan, I N

    2005-06-01

    Pituitary adenomas are the third most common benign intracranial tumor seen in neurosurgical practice. They represent >or= 15 % of all primary intracranial tumors with 25 % prevalence as reported in autopsy series. Advances in biomedical assays, imaging studies support their diagnosis and tailor their management. The direct endonasal transsphenoidal surgery is the recommended intervention for adenoma resection in more than 95 %. The safety and efficacy of this intervention was enhanced by microsurgery and more recently by the introduction of neuronavigation, assisted endoscopy and intraoperative MRI. Anticipation of clinical, biochemical, radiological and surgical pitfalls by a multidisciplinary team is of paramount importance in improving treatment and preventing potential complications.

  13. Insular gliomas and the role of intraoperative assistive technologies: Results from a volumetry-based retrospective cohort.

    PubMed

    Barbosa, Breno José Alencar Pires; Dimostheni, Artemisia; Teixeira, Manoel Jacobsen; Tatagiba, Marcos; Lepski, Guilherme

    2016-10-01

    In the field of Glioma surgery, there has been an increasing interest in the use of assistive technologies to overcome the difficulty of preserving brain function while improving surgical radicality. In most reports, tumor localization has seldom been considered a variable and the role of intraoperative adjuncts is yet to be determined for gliomas of the insula. To evaluate the efficacy of fluorescence-guided resection with 5-ALA, intraoperative neurophysiological monitoring (IOM), neuronavigation, and tractography in the Extent of Resection (EOR), functionality scores, overall survival (OS) and progression-free survival (PFS) in a retrospective cohort of insular gliomas. We reviewed all cases of insular tumors operated on at the Department of Neurosurgery, University Hospital of Tübingen - Germany, between May 2008 and November 2013. EOR was determined by volumetric analysis. Mann Whitney, Chi-square and Kaplan Meier functions were used for assessment of each technology's effect on primary and secondary outcomes. 28 cases (18 men (64%) and 10 women (36%); median age at diagnosis: 52.5 years, range 12 - 59) were considered eligible for analysis. High grade and low grade gliomas accounted for 20 (71%) and 8 (29%) cases, respectively. The most used technologies were IOM (64%) and Neuronavigation (68%). 5-ALA was the only technique associated with EOR ≥90% (p=0.05). Tractography determined improvement in the Karnofsky Performance Scale (50% vs. 5% cases improved, p=0.02). There was a positive association between the use of neuronavigation and overall survival (23 vs. 27.4 months, p=0.03), but the use of 5-ALA was associated with shorter OS (34.8 vs. 21.1 months, p=0.01) and PFS (24.4 vs. 11.8, p=0.01). We demonstrate for the first time that for insular gliomas 5-ALA plays a role in achieving higher EOR, although this technology was associated with poor OS and PFS; also tractography and neuronavigation can be of great importance in the treatment of insular gliomas

  14. Localisation of the sensorimotor cortex during surgery for brain tumours: feasibility and waveform patterns of somatosensory evoked potentials

    PubMed Central

    Romstock, J; Fahlbusch, R; Ganslandt, O; Nimsky, C; Strauss, C

    2002-01-01

    Objective: Intraoperative localisation of the sensorimotor cortex using the phase reversal of somatosensory evoked potentials (SEPs) is an essential tool for surgery in and around the perirolandic gyri, but unsuccessful and perplexing results have been reported. This study examines the effect of tumour masses on the waveform characteristics and feasibility of SEP compared with functional neuronavigation and electrical motor cortex mapping. Methods: In 230 patients with tumours of the sensorimotor region the SEP phase reversal of N20-P20 was recorded from the exposed cortex using a subdural grid or strip electrode. In one subgroup of 80 patients functional neuronavigation was performed with motor and sensory magnetic source imaging and in one subgroup of 40 patients the motor cortex hand area was localised by electrical stimulation mapping. Results: The intraoperative SEP method was successful in 92% of all patients, it could be shown that the success rate rather depended on the location of the lesion than on preoperative neurological deficits. In 13% of the patients with postcentral tumours no N20-P20 phase reversal was recorded but characteristic polyphasic and high amplitude waves at 25 ms and later made the identification of the postcentral gyrus possible nevertheless. Electrical mapping of the motor cortex took up to 30 minutes until a clear result was obtained. It was successful in 37 patients, but failed in three patients with precentral and central lesions. Functional neuronavigation indicating the tumour margins and the motor and sensory evoked fields was possible in all patients. Conclusion: The SEP phase reversal of N20-P20 is a simple and reliable technique, but the success rate is much lower in large central and postcentral tumours. With the use of polyphasic late waveforms the sensorimotor cortex may be localised. By contrast with motor electrical mapping it is less time consuming. Functional neuronavigation is a desirable tool for both preoperative

  15. Image-Guided Endoscopic Endonasal Transmaxillary Transpterygoid Approach to Meckel's Cave.

    PubMed

    Wang, Xuejian; Zhang, Xiaobiao; Hu, Fan; Yu, Yong; Gu, Ye; Xie, Tao; Ge, Junqi

    2016-01-01

    The aim of this report was to summarize our preliminary experience on the resection of tumors located in Meckel's cave via the endoscopic endonasal transmaxillary transpterygoid approach with image-guided system and to investigate the feasibility and efficacy of this approach. Two patients who had tumors in left Meckel's cave underwent surgical treatment using the image-guided endoscopic endonasal transmaxillary transpterygoid approach. This particular technique has advantages of no brain retraction, direct vision of tumor resection and protection of surrounding neurovascular structures. Neuronavigation increases the safety of the endoscopic approach.

  16. Lateral transpeduncular approach to intrinsic lesions of the rostral pons.

    PubMed

    Hebb, Matthew O; Spetzler, Robert F

    2010-03-01

    We describe the lateral transpeduncular approach to access lesions in the rostral pons. The surgical indications and technique are discussed in the context of an illustrative case and pertinent anatomic considerations. A 38-year-old man with acute right hemiparesis and bulbar symptoms had a left pontine hemorrhage with an associated cavernous malformation and venous anomaly. There was no pial or ependymal representation of the lesion. To avoid disruption of eloquent structures, the pia was entered in the posterolateral aspect of the middle cerebellar peduncle. Subsequent dissection was guided by stereotactic neuronavigation in a ventromedial trajectory along the course of the pontocerebellar fibers. The cavernous malformation was resected completely without procedure-related morbidity. The patient's preoperative deficits slowly improved to a functionally independent state. The lateral transpeduncular approach may be used to access intrinsic lesions of the rostral pons with relatively low morbidity. Stereotactic neuronavigation and intraoperative electrophysiological monitoring are important surgical adjuncts to guide dissection and lesion extirpation. Candidate selection, microsurgical technique, and pragmatic treatment goals remain fundamental to optimal patient outcomes.

  17. Symptomatic cysts of the cavum septi pellucidi and cavum vergae: the role of endoscopic neurosurgery in the treatment of four consecutive cases.

    PubMed

    Fratzoglou, M; Grunert, P; Leite dos Santos, A; Hwang, P; Fries, G

    2003-08-01

    Cavum septi pellucidi and cavum vergae are generally asymptomatic fluid collections between the leaves of the septum pellucidum and are present in approximately 15 % of adult brains. These cavities rarely enlarge and become symptomatic causing significant neurological dysfunction as a result of obstruction of the interventricular foramina, distortion of the vascular structures of the deep venous system or compression of the hypothalamoseptal triangle. The authors present a series of four patients with symptoms related directly to pressure effects from the cyst wall to the neighbouring deep brain structures. There were two females and two males with a mean age of 47.5 years. All four patients underwent endoscopic cyst fenestration with a rigid endoscope. In 2 patients frameless neuronavigation was accomplished with the optical tracking system (Radionics, Burlington, USA). All symptoms related to pressure effect resolved after surgery. Endoscopic pellucidotomy of symptomatic cysts of the septum pellucidum produces immediate relief of the mass effect of the cyst and resolution of associated symptoms. Additionally, frameless neuronavigation is a useful tool in planning and realizing the approach and improving intraoperative orientation.

  18. Surgical experience of the ruptured distal anterior cerebral artery aneurysms.

    PubMed

    Lee, Jong-Young; Kim, Moon-Kyu; Cho, Byung-Moon; Park, Se-Hyuck; Oh, Sae-Moon

    2007-10-01

    Distal anterior cerebral artery (DACA) aneurysms are fragile and known to have high risks for intraoperative premature rupture and a relatively high associated morbidity. To improve surgical outcomes of DACA aneurysms, we reviewed our surgical strategy and its results postoperatively. A total of 845 patients with ruptured cerebral aneurysms were operated in our hospital from January 1991 to December 2005. Twenty-three of 845 patients had ruptured DACA aneurysms which were operated on according to our surgical strategy. Our surgical strategy was as follows; early surgery, appropriate releasing of CSF, appropriate surgical approach, using neuronavigating system, securing the bridging veins, using temporary clipping and/or tentative clipping, meticulous manipulation of aneurysm, and using micro-Doppler flow probe. Twenty of 23 patients who had complete medical records were studied retrospectively. We observed the postoperative radiographic findings and checked Glasgow Outcome Scale score sixth months after the operation. Nineteen DACA aneurysms were clipped through a unilateral interhemispheric approach and one DACA aneurysm was clipped through a pterional approach. Postoperative radiographic findings revealed complete clipping of aneurysmal neck without stenosis or occlusion of parent arteries. In two patients, a residual neck of aneurysm was visualized. Seventeen patients showed good recovery, one patient resulted in moderate disability, while 2 patients died. With our surgical strategy it was possible to achieve acceptable surgical morbidity and mortality rates in patients with DACA aneurysms. Appropriate use of tentative clipping, temporary clipping and neuro-navigating systems can give great help for safe approach and clipping of DACA aneurysm.

  19. 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.

  20. Real-time Video-Streaming to Surgical Loupe Mounted Head-Up Display for Navigated Meningioma Resection.

    PubMed

    Diaz, Roberto; Yoon, Jang; Chen, Robert; Quinones-Hinojosa, Alfredo; Wharen, Robert; Komotar, Ricardo

    2017-04-30

    Wearable technology interfaces with normal human movement and function, thereby enabling more efficient and adaptable use.We developed a wearable display system for use with intra-operative neuronavigation for brain tumor surgery. The Google glass head-up display system was adapted to surgical loupes with a video-streaming integrated hardware and software device for display of the Stealth S7 navigation screen. Phantom trials of surface ventriculostomy were performed. The device was utilized as an alternative display screen during cranial surgery. Image-guided brain tumor resection was accomplished using Google Glass head-up display of Stealth S7 navigation images. Visual display consists of navigation video-streaming over a wireless network. The integrated system developed for video-streaming permits video data display to the operating surgeon without requiring movement of the head away from the operative field. Google Glass head-up display can be used for intra-operative neuronavigation in the setting of intracranial tumor resection.

  1. Operative Management of Intraventricular Central Neurocytomas: An Analysis of a Surgical Experience with 32 Cases.

    PubMed

    Chen, Li-Feng; Yang, Yang; Ma, Xiao-Dong; Yu, Xin-Guang; Xu, Bai-Nan; Zhou, Ding-Biao

    2016-01-01

    To better understand the clinical characteristics of central neurocytoma (CN), as well as to assess the optimum therapeutic schedule. This was a retrospective study of 32 patients with CN who visited our department between January 2008 and January 2013. We analyzed the clinical and radiological presentations, tumor characteristics, surgical strategies, and the prognosis. We performed operation guided by combined intraoperative magnetic resonance imaging (iMRI) and neuronavigation in 25 patients. The iMRI detected residual tumor in 9 cases, and further resection was performed in 5 cases. Total and nearly total tumor resection was achieved in 29 cases (91%). There was no significant difference between transcortical and transcallosal approaches in complications. Two cases (6%) with recurrence received respectively repeat salvage surgery and radiosurgery at 46 and 50 months after surgery. Thirty patients (94%) had excellent functional outcome (Karnofsky Performance Score ≥80) and 28 patients (88%) resumed their occupations. Our study demonstrates radical surgery with excellent neurological outcomes is the primary treatment of CN. The techniques of resection guided by combined iMRI and neuronavigation seems to enable a higher complete resection rate and reduce the morbidity rate during surgery. We suggest careful clinical observation after initial surgery, and repeat salvage surgery or radiosurgery for recurrent CN.

  2. Applications of Ultrasound in the Resection of Brain Tumors.

    PubMed

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

    2017-01-01

    Neurosurgery makes use of preoperative imaging to visualize pathology, inform surgical planning, and evaluate the safety of selected approaches. The utility of preoperative 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, has 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. Copyright © 2016 by the American Society of Neuroimaging.

  3. Technical feasibility and safety of image-guided parieto-occipital ventricular catheter placement with the assistance of a wearable head-up display.

    PubMed

    Yoon, Jang W; Chen, Robert E; ReFaey, Karim; Diaz, Roberto J; Reimer, Ronald; Komotar, Ricardo J; Quinones-Hinojosa, Alfredo; Brown, Benjamin L; Wharen, Robert E

    2017-05-19

    Wearable technology is growing in popularity as a result of its ability to interface with normal human movement and function. Using proprietary hardware and software, neuronavigation images were captured and transferred wirelessly via a password-encrypted network to the head-up display. The operating surgeon wore a loupe-mounted wearable head-up display during image-guided parieto-occipital ventriculoperitoneal shunt placement in two patients. The shunt placement was completed successfully without complications. The tip of the catheter ended well within the ventricles away from the ventricular wall. The wearable device allowed for continuous monitoring of neuronavigation images in the right upper corner of the surgeon's visual field without the need for the surgeon to turn his head to view the monitors. The adaptable nature of this proposed system permits the display of video data to the operating surgeon without diverting attention away from the operative task. This technology has the potential to enhance image-guided procedures. Copyright © 2017 John Wiley & Sons, Ltd.

  4. Endoscopic endonasal transsphenoidal approach through the bilateral nostrils for pituitary adenomas.

    PubMed

    Yano, Shigetoshi; Kawano, Takayuki; Kudo, Mareina; Makino, Keishi; Nakamura, Hideo; Kai, Yutaka; Morioka, Motohiro; Kuratsu, Jun-ichi

    2009-01-01

    The endoscopic endonasal transsphenoidal approach through the bilateral nostrils was evaluated for the treatment of pituitary adenoma. The surgical approach is through the bilateral nostrils via minimal or wide dissection of the septal mucosa, depending on the degree of tumor extension. After anterior sphenoidotomy, the endoscope is fixed in one nostril and required instrumentation is inserted in either nostril. In addition, neuronavigation and real-time hormone monitoring are used. Tumor removal rate, endocrinological outcomes, and complications were retrospectively assessed in 194 patients with pituitary adenomas who underwent 213 procedures between December 2001 and March 2008. Greater than 95% resection was achieved in 74 of 131 nonfunctioning adenomas, and the removal rate was significantly higher during 2005-2008 compared to 2002-2004 (p < 0.05). Endocrinological remission was achieved in 20 of 26 growth hormone-secreting tumors of Knosp grades 0-2, 16 of 17 microprolactinomas, and 6 of 9 cases of pure Cushing's disease. Postoperative complications were cerebrospinal fluid leakage in 9 cases, visual worsening in 5, anterior pituitary insufficiency in 5, and permanent diabetes insipidus in 2. The bilateral endonasal approach provides a wide working area without the need for special instrumentation. By modifying mucosal dissection, the endoscopic approach provides flexibility and less invasiveness. The use of neuronavigation or intraoperative hormone monitoring leads to improved surgical results. The present study confirms that this approach is suitable for more extensive sellar tumors.

  5. 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.

  6. Midline filum of the sellar dura: a useful landmark during endoscopic transsphenoidal pituitary surgery.

    PubMed

    Zada, Gabriel; Kim, Albert H; Governale, Lance S; Laws, Edward R

    2010-12-01

    During endoscopic transsphenoidal pituitary surgery, identification and constant awareness of the midline is imperative to prevent injury to critical lateral structures, such as the internal carotid arteries. To describe the relevance of a midline filum of the sellar dura which, when present, can serve as a useful intraoperative anatomic marker. Intraoperative video recordings of twenty patients undergoing endoscopic transsphenoidal surgery were retrospectively reviewed to assess for the presence and location of a midline dural filum or apparent central dural vascular structure. Prospective intraoperative data were gathered on an additional 16 patients. A midline dural filum was identified in 18 of 36 patients (50%) undergoing endoscopic transsphenoidal surgery. This structure was identified on the midline in all cases, as confirmed by intraoperative neuronavigation and comparison with the vomer. The midline dural filum was identified as a strand-like dural extension (13 patients) or as a small vascular dural structure usually exhibiting low pressure venous bleeding (5 patients). Samples of the midline dural filum were obtained from 2 patients for histopathological analysis, which demonstrated dense collagenous connective tissue without evidence of vessel wall or ductal epithelium. In addition to anatomic structures such as the vomer and midline sphenoid sinus septations, a midline dural filum serves as a useful marker during the sellar phase of endoscopic transsphenoidal surgery. Along with intraoperative neuronavigation and Doppler ultrasonography of the cavernous carotid arteries, identification of this structure may further aid in safeguarding against injury to critical paramedian structures.

  7. 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.

  8. Strategies for brain shift evaluation.

    PubMed

    Hastreiter, Peter; Rezk-Salama, Christof; Soza, Grzegorz; Bauer, Michael; Greiner, Günther; Fahlbusch, Rudolf; Ganslandt, Oliver; Nimsky, Christopher

    2004-12-01

    For the analysis of the brain shift phenomenon different strategies were applied. In 32 glioma cases pre- and intraoperative MR datasets were acquired in order to evaluate the maximum displacement of the brain surface and the deep tumor margin. After rigid registration using the software of the neuronavigation system, a direct comparison was made with 2D- and 3D visualizations. As a result, a great variability of the brain shift was observed ranging up to 24 mm for cortical displacement and exceeding 3 mm for the deep tumor margin in 66% of all cases. Following intraoperative imaging the neuronavigation system was updated in eight cases providing reliable guidance. For a more comprehensive analysis a voxel-based nonlinear registration was applied. Aiming at improved speed of alignment we performed all interpolation operations with 3D texture mapping based on OpenGL functions supported in graphics hardware. Further acceleration was achieved with an adaptive refinement of the underlying control point grid focusing on the main deformation areas. For a quick overview the registered datasets were evaluated with different 3D visualization approaches. Finally, the results were compared to the initial measurements contributing to a better understanding of the brain shift phenomenon. Overall, the experiments clearly demonstrate that deformations of the brain surface and deeper brain structures are uncorrelated.

  9. 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

  10. Intra-operative correction of brain-shift.

    PubMed

    Reinertsen, Ingerid; Lindseth, Frank; Askeland, Christian; Iversen, Daniel Høyer; Unsgård, Geirmund

    2014-07-01

    Brain-shift is a major source of error in neuronavigation systems based on pre-operative images. In this paper, we present intra-operative correction of brain-shift using 3D ultrasound. The method is based on image registration of vessels extracted from pre-operative MRA and intra-operative power Doppler-based ultrasound and is fully integrated in the neuronavigation software. We have performed correction of brain-shift in the operating room during surgery and provided the surgeon with updated information. Here, we present data from seven clinical cases with qualitative and quantitative error measures. The registration algorithm is fast enough to provide the surgeon with updated information within minutes and accounts for large portions of the experienced shift. Correction of brain-shift can make pre-operative data like fMRI and DTI reliable for a longer period of time and increase the usefulness of the MR data as a supplement to intra-operative 3D ultrasound in terms of overview and interpretation.

  11. Evolution in management of otogenic brain abscess.

    PubMed

    Szyfter, Witold; Kruk-Zagajewska, Aleksandra; Borucki, Lukasz; Bartochowska, Anna

    2012-04-01

    To present the therapeutic results related with treating 103 patients with cerebral abscesses of otogenic origin during 3 various time frames (1953-1977, 1978-1989, and 1990-2011). A total of 103 patients with cerebral abscess of otogenic origin. Diagnostics and treatment. Analysis of mortality rates, abscess location and its basis, coexisting complications, neurological condition at admittance, bacteriological tests, and presentation of the results of abscess treatment with the use of neuronavigation. Mortality rates dropped systematically from the initial value of 35% observed between 1953 and 1977, to 14% between 1978 and 1989, and finally reached 3% between 1990 and 2011. Abscesses were mainly located within the temporal lobe. They predominantly resulted from chronic inflammation of the middle ear. A wide panel of complications was associated with them. Strong concurrence between results of cultures taken from the ear and the abscess was noted. Cerebral abscesses remain one of the most severe complications related with inflammation of the middle ear. Both the operative methods and the postoperative care evolved (introduction of surgical microscope, new generation of antibiotics), the preoperative diagnostics facilitating the diagnosis and localization of the abscess progressed; nonetheless, the principles underlying the operative treatment remained unchanged. Neuronavigation constitutes a very important and supportive element in the management of otogenic brain abscesses.

  12. Quantitative validation of a method for correction of intraoperative brain shift

    NASA Astrophysics Data System (ADS)

    Bates, Lisa M.; Goerss, Stephan J.; Robb, Richard A.

    2000-05-01

    Stereotactic neuronavigational systems have demonstrated significant clinical influence during the past decade, and are being used in an increasing number of neurosurgical procedures. Pre-operatively acquired 3D images are used for planning purposes, and also are employed in intraoperative navigations to help localize and resect brain lesions. However, as the operation progresses, multiple factors contribute the changes that limit the accuracy of the navigation based on pore-operative images alone. The opening of the dura with the associated loss of CSF and cortical swelling, the effect of gravity relative to the craniotomy location, tumor decompression, and collapse of neural tissue around the operative site are some of the factors that contribute to errors in navigation, particularly navigation based solely on pre-operatively acquired images. Neuronavigational system assume a one-to-one correlation between patient anatomy in the operating room and the pre- operatively acquired MRI images. Since the brain deforms in a non-linear manner, intraoperative brain shift can really only be corrected via intraoperative sensing methods that effectively update the pre-operatively acquired image data during surgery.

  13. 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

  14. Symptomatic pineal cyst: case report and review of the literature.

    PubMed

    Costa, F; Fornari, M; Valla, P; Servello, D

    2008-08-01

    Asymptomatic cysts of the pineal region are common incidental findings in adults. In contrast, symptomatic pineal cysts are rare and their management is not well defined. We present the case of a 39-year-old woman suffering from intracranial hypertension, with visual disturbance and mild papilledema. The MR images showed a voluminous cyst of the pineal region responsible for an obstructive hydrocephalus. Endoscopic treatment with the aid of computerized neuronavigation consisting in third ventriculostomy and fenestration of the cyst was performed. Intracranial hypertension symptoms resolved in 24 hours. The one year follow-up cerebral MR images demonstrated the normalization of ventricular size with patency of the aqueduct of Sylvius. Reviewing the literature demonstrates that the endoscopic approach represents a minimally invasive and safe procedure in the treatment of symptomatic pineal cysts.

  15. 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.

  16. Brain tumor resection guided by fluorescence imaging

    NASA Astrophysics Data System (ADS)

    Leblond, Frederic; Fontaine, Kathryn M.; Valdes, Pablo; Ji, Songbai; Pogue, Brian W.; Hartov, Alex; Roberts, David W.; Paulsen, Keith D.

    2009-02-01

    We present the methods that are being used in the scope of an on-going clinical trial designed to assess the usefulness of ALA-PpIX fluorescence imaging when used in conjunction with pre-operative MRI. The overall objective is to develop imaging-based neuronavigation approaches to aid in maximizing the completeness of brain tumor resection, thereby improving patient survival rate. In this paper we present the imaging methods that are used, emphasizing technical aspects relating to the fluorescence optical microscope, including initial validation approaches based on phantom and small-animal experiments. The surgical workflow is then described in detail based on a high-grade glioma resection we performed.

  17. 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.

  18. 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

  19. Estimation of intra-operative brain shift based on constrained Kalman filter.

    PubMed

    Shakarami, M; Suratgar, A A; Talebi, H A

    2015-03-01

    In this study, the problem of estimation of brain shift is addressed by which the accuracy of neuronavigation systems can be improved. To this end, the actual brain shift is considered as a Gaussian random vector with a known mean and an unknown covariance. Then, brain surface imaging is employed together with solutions of linear elastic model and the best estimation is found using constrained Kalman filter (CKF). Moreover, a recursive method (RCKF) is presented, the computational cost of which in the operating room is significantly lower than CKF, because it is not required to compute inverse of any large matrix. Finally, the theory is verified by the simulation results, which show the superiority of the proposed method as compared to one existing method. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  20. Indocyanine green fluorescence endoscopy at endonasal transsphenoidal surgery for an intracavernous sinus dermoid cyst: case report.

    PubMed

    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.

  1. Intraoperative magnetic resonance imaging in neurosurgery: the Brigham concept.

    PubMed

    Mittal, S; Black, P M

    2006-01-01

    The resection of brain tumors is limited by the surgeon's ability to precisely define margins. To overcome this problem, various neuronavigational tools have been used. The development of image-guided navigation systems represents a substantial improvement in the microsurgical treatment of various intracranial lesions. However, a major drawback of this technology is that they use images acquired preoperatively, on which the surgical planning and intraoperative performance is based. As the intracranial anatomy dynamically changes during a neurosurgical procedure, only intraoperatively acquired images can provide the neurosurgeon with the information needed to perform real-time, image-guided surgery. Because magnetic resonance imaging best delineates the soft-tissue extent of most tumors, it currently remains the superior method for intraoperative image guidance. In this review, we outline the development as well as current and possible future applications of the intraoperative MRI (iMRI) unit at the Brigham and Women's Hospital, Boston, MA.

  2. 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

    2017-01-23

    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.

  3. Frontal lobe epilepsy with atypical seizure semiology resembling shuddering attacks or wet dog shake seizures.

    PubMed

    Jahodova, Alena; Krsek, Pavel; Komarek, Vladimir; Kudr, Martin; Kyncl, Martin; Zamecnik, Josef; Tichy, Michal

    2012-03-01

    We report a girl with a drug-resistant frontal lobe epilepsy caused by focal cortical dysplasia, who exhibited uncommon seizures. The seizures consisted of shoulder or whole body shuddering after a short psychic aura and face grimacing. Consciousness was fully preserved. The seizures resembled "wet dog shake" seizures described in rat models of epilepsy or shuddering attacks in infants. EEG findings were inconclusive, however, MRI showed a clear dysplastic lesion in the right frontal mesial and polar structures. The patient underwent an extended lesionectomy guided by neuronavigation and intraoperative electrocorticography. Focal cortical dysplasia type Ib was histologically confirmed and the patient has been seizure-free for the three years following resection. [Published with video sequences].

  4. Preoperative functional MRI localization of language areas in Chinese patients with brain tumors

    PubMed Central

    Xia, Hechun; Huang, Wei; Wu, Liang; Ma, Hui; Wang, Xiaodong; Chen, Xuexin; Sun, Shengyu; Jia, Xiaoxiong

    2012-01-01

    Ten Chinese patients with brain tumors involving language regions were selected. Preoperative functional MRI was performed to locate Broca's or Wernicke's area, and the cortex that was essential for language function was determined by electrocortical mapping. A site-by-site comparison between functional MRI and electrocortical mapping was performed with the aid of a neuronavigation device. Results showed that the sensitivity and specificity of preoperative functional MRI were 80.0% and 85.0% in Broca's area and 66.6% and 85.2% in Wernicke's area, respectively. These experimental findings indicate that functional MRI is an accurate, reliable technique with which to identify the location of Wernicke's area or Broca's area in patients with brain tumors. PMID:25657694

  5. Endoscopic endonasal transphenoidal surgery using the BrainLAB® Headband for navigation without rigid fixation.

    PubMed

    Duque, Sara G; Gorrepati, Ramana; Kesavabhotla, Kartik; Huang, Clark; Boockvar, John A

    2014-07-01

    The number of lesions of the skull base currently resected via endoscopic, endonasal, transphenoidal approach has increased. We have successfully treated 63 consecutive patients with pituitary lesions using this technique in combination with BrainLAB reference headband and laser surface scanning (BrainLAB(®), Heimstetten, Germany) for surgical navigation. This technique affords several advantages over neuronavigation based on adhesive-mounted fiducial registration. Rigid fixation in a Mayfield clamp is not required, which allows for flexibility with respect to positioning of the head during the procedure. This is particularly important, as extension and flexion of the head provide greater exposure to the clivus and anterior skull base, respectively. Also, we demonstrate that this technique is safe, easy-to-use, and faster compared with other ones. Georg Thieme Verlag KG Stuttgart · New York.

  6. 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

  7. Endoscopic endonasal transsphenoidal surgery using a skull reference array and laser surface scanning.

    PubMed

    Greenfield, J P; Howard, B M; Huang, C; Boockvar, J A

    2008-08-01

    Lesions of the skull base are increasingly being resected via the endoscopic, endonasal, transphenoidal approach. We have successfully treated 33 consecutive patients with pituitary lesions using this technique in combination with BrainLAB skull reference array and laser surface scanning for surgical navigation. This technique affords several advantages over neuronavigation based on adhesive-mounted fiducial registration. Rigid fixation in a Mayfield clamp is not required, which allows for flexibility with respect to positioning of the head during the procedure. This is particularly important as extension and flexion of the head provide greater exposure to the clivus and anterior skull base respectively. Also, this technique obviates the need for additional preoperative MRI, thereby reducing cost and delays.

  8. Intraoperative 3D Computed Tomography: Spine Surgery.

    PubMed

    Adamczak, Stephanie E; Bova, Frank J; Hoh, Daniel J

    2017-10-01

    Spinal instrumentation often involves placing implants without direct visualization of their trajectory or proximity to adjacent neurovascular structures. Two-dimensional fluoroscopy is commonly used to navigate implant placement, but with the advent of computed tomography, followed by the invention of a mobile scanner with an open gantry, three-dimensional (3D) navigation is now widely used. This article critically appraises the available literature to assess the influence of 3D navigation on radiation exposure, accuracy of instrumentation, operative time, and patient outcomes. Also explored is the latest technological advance in 3D neuronavigation: the manufacturing of, via 3D printers, patient-specific templates that direct implant placement. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Advanced computer-aided intraoperative technologies for information-guided surgical management of gliomas: Tokyo Women's Medical University experience.

    PubMed

    Iseki, H; Nakamura, R; Muragaki, Y; Suzuki, T; Chernov, M; Hori, T; Takakura, K

    2008-10-01

    The availability of the intraoperative MRI and real-time neuronavigation has dramatically changed the principles of surgery for gliomas. Current intraoperative computer-aided technologies permit perfect localization of the neoplasm, precise estimation of its volume, and clear definition of its interrelationships with the eloquent brain structures. This allows maximal tumor resection with minimal risk of postoperative disabilities. Under such conditions the medical treatment has become significantly dependent on the quality of the provided information and can be designated as information-guided management. Therefore, appropriate management of the wide spectrum of the intraoperative medical data and its adequate distribution between members of the surgical team for facilitation of the clinical decision-making is very important for attainment of the best possible outcome. Further progress in advanced neurovisualization, robotics, and comprehensive medical information technology has a great potential to increase the safety of the neurosurgical procedures for parenchymal brain tumors in the eloquent brain areas.

  10. 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

    2017-07-08

    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.

  11. PubMed Central

    BATTAGLIA, P.; BIGNAMI, M.; FERRELI, F.; TURRI-ZANONI, M.; BERNARDINI, E.; LENZI, R.; DALLAN, I.

    2012-01-01

    SUMMARY The surgical treatment of sinonasal malignancies is in continuous evolution. In selected patients, endoscopic resection has become a sound alternative to traditional external approaches. Further improvements are necessary to enhance the possibilities of endoscopic transnasal resection of sinonasal malignancies. We present a case of intestinal-type adenocarcinoma of the left nasal fossa eroding the skull base that affected a 56-year-old male. The patient was surgically-treated by means of a four-hand binarial endoscopic transnasal resection using a 3D endoscopic system and neuronavigation. Surgery was completed in 5 hours without significant complications. Surgeons were able to recognize and manage anatomical structures, and to control bleeding easily thanks to the bimanual technique and 3D visualization. The new 3D scopes and the bimanual technique under the guidance of a navigation system represent an interesting solution that can overcome the traditional limits of the traditional set up currently used. PMID:22767985

  12. Percutaneous ultrasound-guided insertion of ventriculo-atrial shunts.

    PubMed

    McCracken, James Albert; Bahl, Anuj; McMullan, John

    2016-08-01

    Ventriculo-atrial (VA) shunts have been in use for >60 years but less frequently so of late. This is due to a combination of the risk of cardiac complications, lack of expertise and a lengthy operation. We present our consecutive prospective series of 10 VA shunts inserted using a percutaneous method employing the Sonowand Invite™ neuronavigation system for both the distal and proximal catheters, over a 13-month period. We had two complications of cases needing revision, but our series highlights a safe and reproducible method of inserting a VA shunt. About 30% of the procedures were carried out by a trainee as the primary surgeon. This technique does not necessarily require the expertise of a complex hydrocephalus surgeon and is thus able to be in the armoury of any neurosurgeon needing to do a VA shunt procedure. The indications, operative data and outcomes of our patients are discussed.

  13. 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

  14. Add-on rTMS for treatment of depression: a pilot study using stereotaxic coil-navigation according to PET data.

    PubMed

    Herwig, Uwe; Lampe, Yvonne; Juengling, Freimut D; Wunderlich, Arthur; Walter, Henrik; Spitzer, Manfred; Schönfeldt-Lecuona, Carlos

    2003-01-01

    Repetitive transcranial magnetic stimulation (rTMS) is regarded as a potentially new tool to treat depression. In a double-blind, randomized, sham-controlled pilot study we investigated the efficacy of neuronavigated rTMS, guided according to the prefrontal metabolic state determined by positron emission tomography (PET). 25 patients with major depression were included. Prior to rTMS, PET scans were obtained. For the real stimulation condition, the dorsolateral prefrontal cortex (DLPFC) with lower metabolic activity compared to the contralateral hemisphere was selected, if detected by prior PET. Stimulation parameters were 15 Hz, 110% motor threshold (MT), 3000 stimuli/day, for 10 days. A neuronavigational system was used to place the magnetic coil above each individuals' selected cortical region (real condition: DLPFC, sham: midline parieto-occipital, intensity 90% of MT). RTMS was administered add-on to medication. Depression-related symptoms were rated with Beck's, Hamilton's (HAM-D), and Montgomery-Asberg's (MADRS) depression rating scales. Real stimulation improved depression according to HAM-D and MADRS moderately but significantly better compared to sham at the end of the stimulation sessions. In the real condition, four out of 13 patients responded with a mean improvement in HAM-D and/or MADRS of at least 50%, whereas none responded to sham. Antidepressant effects of stimulation of the relatively hypometabolic DLPFC were comparable to stimulation in absence of metabolic differences. A moderate improvement of depressive symptoms after rTMS was observed. Our preliminary data show that stimulation of prefrontal hypometabolism may not be advantageous to stimulation irrespective of the metabolic state.

  15. 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.

  16. 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.

  17. Augmented reality in neurosurgery: a systematic review.

    PubMed

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

    2016-05-07

    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.

  18. Surgical leg rotation: cortical neuroplasticity assessed through brain mapping using transcranial magnetic stimulation.

    PubMed

    Tesio, Luigi; Benedetti, Maria Grazia; Rota, Viviana; Manfrini, Marco; Perucca, Laura; Caronni, Antonio

    2014-12-01

    Rotationplasty (Borggreve-Van Nes operation) is a rare limb salvage procedure, most often applied to children presenting with sarcoma of the distal femur. In type A1 operation, the distal thigh is removed and the proximal tibia is axially rotated by 180°, remodeled, grafted onto the femoral stump, and then prosthetized. The neurovascular bundle is spared. The rotated ankle then works as a knee. The foot plantar and dorsal flexors act as knee extensors and flexors, respectively. Functional results may be excellent. Cortical neuroplasticity was studied in three men (30-31 years) who were operated on the left lower limb at ages between 7 and 11 years and were fully autonomous with a custom-made prosthesis, as well as in three age-sex matched controls. The scalp stimulation coordinates, matching the patients' brain MRI spots, were digitized through a 'neuronavigation' optoelectronic system, in order to guide the transcranial magnetic stimulation coil, thus ensuring spatial precision during the procedure. Through transcranial magnetic stimulation driven by neuronavigation, the cortical representations of the contralateral soleus and vastus medialis muscles were studied in terms of amplitude of motor evoked potentials (MEPs) and centering and width of the cortical areas from which the potentials could be evoked. Map centering on either hemisphere did not differ substantially across muscles and participants. In the operated patients, MEP amplitudes, the area from which MEPs could be evoked, and their product (volume) were larger for the muscles of the unaffected side compared with both the rotated soleus muscle (average effect size 0.75) and the muscles of healthy controls (average effect size 0.89). In controls, right-left differences showed an effect size of 0.38. In no case did the comparisons reach statistical significance (P>0.25). Nevertheless, the results seem consistent with cortical plasticity reflecting strengthening of the unaffected leg and a combination of

  19. Implementation of fiber tract navigation.

    PubMed

    Nimsky, Christopher; Ganslandt, Oliver; Fahlbusch, Rudolf

    2007-07-01

    To implement fiber tracking in a common neuronavigation environment for routine clinical use to visualize major white matter tracts intraoperatively. A single-shot, spin-echo diffusion weighted echo planar imaging sequence with six diffusion directions on a 1.5 T magnetic resonance scanner was used for diffusion tensor imaging. For three-dimensional (3-D) tractography, we applied a knowledge-based multiple volume of interest approach. Tracking was initiated in each voxel of the initial seed volume in retrograde and orthograde directions according to the direction of the major eigenvector by applying a tensor deflection algorithm. Tractography results were displayed as streamlines assigned direction encoding color. After selecting the fiber tract bundle of interest by defining inclusion and exclusion volumes, a 3-D object was generated automatically by wrapping the whole fiber tract bundle. This 3-D object was displayed along with other contours representing tumor outline and further functional data with the microscope heads-up display. In 16 patients (three cavernomas, 13 gliomas), major white matter tracts (pyramidal tract, n = 14; optic radiation, n = 2) were visualized intraoperatively with a standard navigation system. Three patients developed a postoperative paresis, which resolved in two in the postoperative course. Additional planning time for tractography amounted to up to 10 minutes. Comparing the tractography results with a fiber bundle generated on a different platform by applying a distortion-free sequence revealed a good congruency of the defined 3-D outlines in the area of interest. Fiber tract data can be reliably integrated into a standard neuronavigation system, allowing for intraoperative visualization and localization of major white matter tracts such as the pyramidal tract or optic radiation.

  20. Implementation of fiber tract navigation.

    PubMed

    Nimsky, Christopher; Ganslandt, Oliver; Fahlbusch, Rudolf

    2006-04-01

    To implement fiber tracking in a common neuronavigation environment for routine clinical use to visualize major white matter tracts intraoperatively. A single-shot, spin-echo diffusion weighted echo planar imaging sequence with six diffusion directions on a 1.5 T magnetic resonance scanner was used for diffusion tensor imaging. For three-dimensional (3-D) tractography, we applied a knowledge-based multiple volume of interest approach. Tracking was initiated in each voxel of the initial seed volume in retrograde and orthograde directions according to the direction of the major eigenvector by applying a tensor deflection algorithm. Tractography results were displayed as streamlines assigned direction encoding color. After selecting the fiber tract bundle of interest by defining inclusion and exclusion volumes, a 3-D object was generated automatically by wrapping the whole fiber tract bundle. This 3-D object was displayed along with other contours representing tumor outline and further functional data with the microscope heads-up display. In 16 patients (three cavernomas, 13 gliomas), major white matter tracts (pyramidal tract, n = 14; optic radiation, n = 2) were visualized intraoperatively with a standard navigation system. Three patients developed a postoperative paresis, which resolved in two in the postoperative course. Additional planning time for tractography amounted to up to 10 minutes. Comparing the tractography results with a fiber bundle generated on a different platform by applying a distortion-free sequence revealed a good congruency of the defined 3-D outlines in the area of interest. Fiber tract data can be reliably integrated into a standard neuronavigation system, allowing for intraoperative visualization and localization of major white matter tracts such as the pyramidal tract or optic radiation.

  1. 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.

  2. High-field iMRI in glioblastoma surgery: improvement of resection radicality and survival for the patient?

    PubMed

    Mehdorn, H Maximilian; Schwartz, Felix; Dawirs, Stefan; Hedderich, Jürgen; Dörner, Lutz; Nabavi, Arya

    2011-01-01

    Since the first patients underwent intracranial tumor removal with the radicality control of intraoperative MRI (ioMRI) in September 2005 in our department, the majority of operations performed in the ioMRI room have been indicated for high grade gliomas. In order to elucidate the role of ioMRI scanning in patients harboring high-grade gliomas (HGG) on their survival, one hundred ninety three patients with gliomas WHO grades III and IV were operated either in a standard microsurgical neuronavigated fashion or using additionally ioMRI and were included in a follow-up study. The series started with surgeries from September 2005 until October 2007. Patient attribution to the two groups was based on the logistical availability of the ioMRI on a scheduled surgery day, and on the assumed "difficulty" of the surgery based on the location of the glioma in or near to an eloquent area. Surgery was intended to be as radical as possible without reduction of quality of life. First surgery was performed in 103 patients (75 WHO IV and 28 WHO III) and will be the main topic of this paper. In 60 patients, ioMRI was used, while in 43 patients standard microsurgical neuronavigated resection techniques were applied. Patients were followed in regular intervals mostly until death. Statistical analysis showed a median survival time for patients in whom ioMRI had been used of 20, 37 months compared to 10, 3 months in the cohort who had undergone conventional microsurgical removal. Major influencing concomitants were WHO grades and age which were balanced in both groups.

  3. Contemporary frameless intracranial biopsy techniques: Might variation in safety and efficacy be expected?

    PubMed

    Verploegh, Iris S C; Volovici, Victor; Haitsma, Iain K; Schouten, Joost W; Dirven, Clemens M; Kros, Johan M; Dammers, Ruben

    2015-11-01

    Frameless stereotactic neuronavigation has proven to be a feasible technology to acquire brain biopsies with good accuracy and little morbidity and mortality. New systems are constantly introduced into the neurosurgical armamentarium, although few studies have actually evaluated and compared the diagnostic yield, morbidity, and mortality of various manufacturer's frameless neuronavigation systems. The present study reports our experience with brain biopsy procedures performed using both the Medtronic Stealth Treon(TM) Vertek® and BrainLAB® Varioguide frameless stereotactic brain biopsy systems. All 247 consecutive biopsies from January 2008 until May 2013 were evaluated retrospectively. One hundred two biopsies each were performed using the Medtronic (2008-2009) and BrainLAB® system (2011-2013), respectively. The year 2010 was considered a transition year, in which 43 biopsies were performed with either system. Patient demographics, perioperative characteristics, and histological diagnosis were reviewed, and a comparison was made between the two brain biopsy systems. The overall diagnostic yield was 94.6 %, i.e., 11 biopsies were nondiagnostic, 5 (4.9 %) with the Medtronic and 6 (5.9 %) with the BrainLAB® system. No differences besides the operating time (108 vs 120 min) were found between the two biopsy methods. On average, 6.6 tissue samples were taken with either technique. Peri- and postoperative complications were seen in 5.3 % and 12.9 %, consisting of three symptomatic hemorrhages (1.2 %). Biopsy-related mortality occurred in 0.8 % of all biopsies. Regarding diagnostic yield, complication rate, and biopsy-related mortality, there seems to be no difference between the frameless biopsy technique from Medtronic and BrainLAB®. In contemporary time, the neurosurgeon has many tools to choose from, all with a relatively fast learning curve and ever improving feasibility. Thus, the issue of choice involves not the results, but the familiarity, end

  4. Endoscopic endonasal trans-sphenoid surgery of pituitary adenoma.

    PubMed

    Yadav, Yr; Sachdev, S; Parihar, V; Namdev, H; Bhatele, Pr

    2012-09-01

    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.

  5. 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

  6. 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.

  7. Surgical Experience of the Ruptured Distal Anterior Cerebral Artery Aneurysms

    PubMed Central

    Lee, Jong-Young; Kim, Moon-Kyu; Cho, Byung-Moon; Park, Se-Hyuck

    2007-01-01

    Objective Distal anterior cerebral artery (DACA) aneurysms are fragile and known to have high risks for intraoperative premature rupture and a relatively high associated morbidity. To improve surgical outcomes of DACA aneurysms, we reviewed our surgical strategy and its results postoperatively. Methods A total of 845 patients with ruptured cerebral aneurysms were operated in our hospital from January 1991 to December 2005. Twenty-three of 845 patients had ruptured DACA aneurysms which were operated on according to our surgical strategy. Our surgical strategy was as follows; early surgery, appropriate releasing of CSF, appropriate surgical approach, using neuronavigating system, securing the bridging veins, using temporary clipping and/or tentative clipping, meticulous manipulation of aneurysm, and using micro-Doppler flow probe. Twenty of 23 patients who had complete medical records were studied retrospectively. We observed the postoperative radiographic findings and checked Glasgow Outcome Scale score sixth months after the operation. Results Nineteen DACA aneurysms were clipped through a unilateral interhemispheric approach and one DACA aneurysm was clipped through a pterional approach. Postoperative radiographic findings revealed complete clipping of aneurysmal neck without stenosis or occlusion of parent arteries. In two patients, a residual neck of aneurysm was visualized. Seventeen patients showed good recovery, one patient resulted in moderate disability, while 2 patients died. Conclusion With our surgical strategy it was possible to achieve acceptable surgical morbidity and mortality rates in patients with DACA aneurysms. Appropriate use of tentative clipping, temporary clipping and neuro-navigating systems can give great help for safe approach and clipping of DACA aneurysm. PMID:19096557

  8. 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.

  9. Assessment and Treatment of Peritumoral Cortical Veins in Parasagittal Meningiomas with Application of 3-Dimensional Imaging Fusion Model.

    PubMed

    Yin, Tengkun; Gu, Jianjun; Huang, Yinxing; Wei, Liangfeng; Gao, Jinxi; Wang, Shousen

    2017-08-01

    Operation of cortical veins is the keystone of parasagittal meningioma (PSM) resection. Little is known about pathologic changes of the veins and proper treatment. We built 3-dimensional (3D) image fusion models by neuronavigation to analyze the features of peritumoral cortical veins for PSMs and explore intraoperative treatment options. We performed a prospective study of 42 consecutive surgically treated PSM patients who underwent preoperative evaluation of peritumoral cortical veins using a 3D venous-tumor fusion model established by a neuronavigation system. We categorized cortical veins into 3 types: single-end anastomosis (type a), tumor-to-end anastomosis (type b), and end-to-end anastomosis (type c). We present surgical strategies to operate these veins. Preoperative evaluation demonstrated 39 patients with peritumoral cortical veins. The 3D models show 100% of the veins (95 in total), which were confirmed intraoperation. The postoperative complication rates after vein injury were 60% (type a), 16.7% (type c), and 0% (type b). Ten patients (23.8%) had residual tumor because of venous protection (equal to Simpson grade III). After correlation analysis, type b and c cortical veins were positively correlated with tumor volume. The anastomoses of cortical veins may provide compensation for venous transaction. There may be a time-evolution relationship between different cortical veins (type a to c to b). Treatment of cortical veins should follow the following principles: single-end veins must be protected, tumor-to-end veins should be transacted directly, and end-to-end veins could be cut selectivity based on the degree of occlusion of the superior sagittal sinus. Detailed preoperative assessment of peritumoral cortical veins is critical for proper treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Subcortical mapping of calculation processing in the right parietal lobe.

    PubMed

    Della Puppa, Alessandro; De Pellegrin, Serena; Lazzarini, Anna; Gioffrè, Giorgio; Rustemi, Oriela; Cagnin, Annachiara; Scienza, Renato; Semenza, Carlo

    2015-05-01

    Preservation of calculation processing in brain surgery is crucial for patients' quality of life. Over the last decade, surgical electrostimulation was used to identify and preserve the cortical areas involved in such processing. Conversely, subcortical connectivity among different areas implicated in this function remains unclear, and the role of surgery in this domain has not been explored so far. The authors present the first 2 cases in which the subcortical functional sites involved in calculation were identified during right parietal lobe surgery. Two patients affected by a glioma located in the right parietal lobe underwent surgery with the aid of MRI neuronavigation. No calculation deficits were detected during preoperative assessment. Cortical and subcortical mapping were performed using a bipolar stimulator. The current intensity was determined by progressively increasing the amplitude by 0.5-mA increments (from a baseline of 1 mA) until a sensorimotor response was elicited. Then, addition and multiplication calculation tasks were administered. Corticectomy was performed according to both the MRI neuronavigation data and the functional findings obtained through cortical mapping. Direct subcortical electrostimulation was repeatedly performed during tumor resection. Subcortical functional sites for multiplication and addition were detected in both patients. Electrostimulation interfered with calculation processing during cortical mapping as well. Functional sites were spared during tumor removal. The postoperative course was uneventful, and calculation processing was preserved. Postoperative MRI showed complete resection of the tumor. The present preliminary study shows for the first time how functional mapping can be a promising method to intraoperatively identify the subcortical functional sites involved in calculation processing. This report therefore supports direct electrical stimulation as a promising tool to improve the current knowledge on

  11. 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.

  12. 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

  13. Metabolic approach for tumor delineation in glioma surgery: 3D MR spectroscopy image-guided resection.

    PubMed

    Zhang, Jie; Zhuang, Dong-Xiao; Yao, Cheng-Jun; Lin, Ching-Po; Wang, Tian-Liang; Qin, Zhi-Yong; Wu, Jin-Song

    2016-06-01

    OBJECT The extent of resection is one of the most essential factors that influence the outcomes of glioma resection. However, conventional structural imaging has failed to accurately delineate glioma margins because of tumor cell infiltration. Three-dimensional proton MR spectroscopy ((1)H-MRS) can provide metabolic information and has been used in preoperative tumor differentiation, grading, and radiotherapy planning. Resection based on glioma metabolism information may provide for a more extensive resection and yield better outcomes for glioma patients. In this study, the authors attempt to integrate 3D (1)H-MRS into neuronavigation and assess the feasibility and validity of metabolically based glioma resection. METHODS Choline (Cho)-N-acetylaspartate (NAA) index (CNI) maps were calculated and integrated into neuronavigation. The CNI thresholds were quantitatively analyzed and compared with structural MRI studies. Glioma resections were performed under 3D (1)H-MRS guidance. Volumetric analyses were performed for metabolic and structural images from a low-grade glioma (LGG) group and high-grade glioma (HGG) group. Magnetic resonance imaging and neurological assessments were performed immediately after surgery and 1 year after tumor resection. RESULTS Fifteen eligible patients with primary cerebral gliomas were included in this study. Three-dimensional (1)H-MRS maps were successfully coregistered with structural images and integrated into navigational system. Volumetric analyses showed that the differences between the metabolic volumes with different CNI thresholds were statistically significant (p < 0.05). For the LGG group, the differences between the structural and the metabolic volumes with CNI thresholds of 0.5 and 1.5 were statistically significant (p = 0.0005 and 0.0129, respectively). For the HGG group, the differences between the structural and metabolic volumes with CNI thresholds of 0.5 and 1.0 were statistically significant (p = 0.0027 and 0

  14. 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

  15. 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

  16. P15.12SURVIVAL AND QUALITY OF LIFE AFTER SURGERY FOR BENIGN INTRACRANIAL TUMOURS: AGE MATTERS?

    PubMed Central

    Nocchi, N.; Iacoangeli, M.; Dobran, M.; Di Rienzo, A.; di Somma, L.; Alvaro, L.; Nasi, D.; Benigni, R.; Sessa, F.; Scerrati, M.

    2014-01-01

    INTRODUCTION: Intracranial benign tumours are an increasingly common condition in the elderly population (>70 years) thanks to the prolonged life expectancy and the improvement of neuroradiological studies. Surgical resection in these patients, even if indicated, could be controversial due to patient's ageing physiology and eventual comorbidities, so it is difficult for surgeons to compare the advantages of a surgical removal against radiosurgery or a “wait and see” behaviour. We report our experience in dealing with patients (>70 years) surgically treated for benign intracranial neoplastic lesions (deep-seated and/or located in eloquent areas). We report how surgery in the elderly could be effective as in younger patients with no higher incidence of complications and reduction of the quality of life and/or survival. METHODS: From January 2010 to January 2014, 42 patients (12 male and 30 female with a mean age of 75 years) were submitted to a benign intracranial tumours surgical removal. The oldest patient was 86 years old. Neurological and physical conditions were assessed preoperatively and neuroradiological examination (MRI or, if it is contraindicated, a CT scan) revealed size and location of the lesions. Intraoperatively we used neuronavigation and neurophysiological monitoring. Outcome data included mortality, recurrence, complications and length of hospital stay (LoS). RESULTS: The patients' pathologies were: meningiomas in 32 patients, followed by 7 pituitary adenomas and 3 acoustic neuromas. In 35 pts a gross total removal was obtained whereas a sub total removal and partial removal were achieved in 5 and 2 pts respectively. Patients had a mean length of hospital stay of 9,7 days. Postoperative complications were observed in 6 patients, represented by CSF leaks (4 pts) and intracerebral haemorrhage (2 pts). There were better postoperative results in patients with few comorbidities and tumours of small dimensions and accessible location. The mortality

  17. NeuRobot: telecontrolled micromanipulator system for minimally invasive microneurosurgery-preliminary results.

    PubMed

    Hongo, Kazuhiro; Kobayashi, Shigeaki; Kakizawa, Yukinari; Koyama, Jun-Ichi; Goto, Tetsuya; Okudera, Hiroshi; Kan, Kazutoshi; Fujie, Masakatsu G; Iseki, Hiroshi; Takakura, Kintomo

    2002-10-01

    Microneurosurgery can be performed less invasively with the recent advances in neuronavigation and neuroendoscopy. For even less invasive microneurosurgery, we have developed a telecontrolled micromanipulator system. The NeuRobot telecontrolled micromanipulator system was developed. With the use of this system, surgical simulations were performed with a human cadaveric head. The system consists of four main parts, i.e., a micromanipulator (slave manipulator), a manipulator-supporting device, an operation-input device (master manipulator), and a three-dimensional display monitor. Three 1-mm forceps and a three-dimensional endoscope, which could be remotely controlled with three degrees of freedom (rotation, neck swinging, and forward/backward motion), were installed in the slave manipulator. All surgical procedures were accurately performed with this system. The use of telecontrolled manipulator systems in neurosurgery is very promising, and we are convinced that this system will facilitate more accurate, less invasive microneurosurgery. The details of the NeuRobot system and preliminary results are presented.

  18. Localization of neurosurgically implanted electrodes via photograph-MRI-radiograph coregistration.

    PubMed

    Dalal, Sarang S; Edwards, Erik; Kirsch, Heidi E; Barbaro, Nicholas M; Knight, Robert T; Nagarajan, Srikantan S

    2008-09-15

    Intracranial electroencephalography (iEEG) is clinically indicated for medically refractory epilepsy and is a promising approach for developing neural prosthetics. These recordings also provide valuable data for cognitive neuroscience research. Accurate localization of iEEG electrodes is essential for evaluating specific brain regions underlying the electrodes that indicate normal or pathological activity, as well as for relating research findings to neuroimaging and lesion studies. However, electrodes are frequently tucked underneath the edge of a craniotomy, inserted via a burr hole, or placed deep within the brain, where their locations cannot be verified visually or with neuronavigational systems. We show that one existing method, registration of postimplant computed tomography (CT) with preoperative magnetic resonance imaging (MRI), can result in errors exceeding 1cm. We present a novel method for localizing iEEG electrodes using routinely acquired surgical photographs, X-ray radiographs, and magnetic resonance imaging scans. Known control points are used to compute projective transforms that link the different image sets, ultimately allowing hidden electrodes to be localized, in addition to refining the location of manually registered visible electrodes. As the technique does not require any calibration between the different image modalities, it can be applied to existing image databases. The final result is a set of electrode positions on the patient's rendered MRI yielding locations relative to sulcal and gyral landmarks on individual anatomy, as well as MNI coordinates. We demonstrate the results of our method in eight epilepsy patients implanted with electrode grids spanning the left hemisphere.

  19. Quantitative analysis of surgical exposure and surgical freedom to the anterosuperior pons: comparison of pterional transtentorial, orbitozygomatic, and anterior petrosal approaches.

    PubMed

    Lee, Jung-Shun; Scerrati, Alba; Zhang, Jun; Ammirati, Mario

    2016-10-01

    Surgical approaches to the pons lump together different areas of the pons, such as the anterosuperior and the anteroinferior pons. These areas are topographically different, and different approaches may be best suited for one or the other area. We evaluated the exposure of the anterosuperior pons using different surgical approaches. We quantify the surgical exposure and surgical freedom to the anterosuperior pons afforded by the pterional transtentorial (PT), the orbitozygomatic with anterior clinoidectomy (OZ), and the anterior petrosal (AP) approaches. Five embalmed cadaver heads were used. The three approaches were executed on each side, for a total of 30 approaches. The area of maximal exposure of the anterosuperior pons was measured with the aid of neuronavigation. We also evaluated the feasible angles of approach in the vertical and horizontal planes. We were able to successfully expose the anterosuperior pons using all the selected approaches. In the PT and OZ approaches, mobilization of the sphenoparietal sinus can prevent over-retraction of the temporal bridging veins, while use of the endoscope can help in preserving the integrity of the fourth nerve while cutting the tentorium. The mean exposure area was largest for the AP and smallest for the PT; the surgical freedom was similar among all the approaches. However, there was no statistically significant difference among all the approaches in the exposure area or in the surgical freedom. There is no significant difference among the three evaluated approaches in exposure of the anterosuperior pons.

  20. 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.

  1. 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.

  2. External ventricular drain insertion accuracy: is there a need for change in practice?

    PubMed

    Toma, Ahmed K; Camp, Sophie; Watkins, Laurence D; Grieve, Joan; Kitchen, Neil D

    2009-12-01

    Free-hand insertion of an external ventricular drain (EVD) is a common emergency neurosurgical procedure, mostly performed for critically ill patients. Although EVD complications have been studied thoroughly, the accuracy of EVD positioning has been audited only occasionally. Post-EVD insertion computed tomographic scans performed in our unit over a 2-year period were analyzed for EVD tip location and intracranial catheter length. A total of 183 post-EVD insertion scans were reviewed. Of those, 73 EVD tips (39.9%) were in the ipsilateral frontal horn of the lateral ventricle (the desired target); of those, 18 (25%) required EVD revision/reinsertion. Of the others, 35 (19.1%) were in the third ventricle, 33 (18%) in the body of the lateral ventricle, 19 (10.4%) in the subarachnoid space, 5 (2.7%) in the contralateral frontal horn, and 18 (9.8%) within the brain parenchyma. When the EVD tip was outside the desired target, 44 of the patients (40%) required EVD revision/reinsertion procedure (P = 0.0383). Free-hand insertion of an EVD is an inaccurate procedure, and further studies are required to assess the accuracy and feasibility of the routine use of neuronavigation, ultrasonography, or other guidance techniques and the possible implication of the decreasing revision rate, complications, and length of hospital stay.

  3. Sensorimotor memory for fingertip forces during object lifting: the role of the primary motor cortex.

    PubMed

    Berner, Julia; Schönfeldt-Lecuona, Carlos; Nowak, Dennis A

    2007-04-09

    When an object is repetitively lifted, the scaling of grip force is influenced by the mechanical properties of the preceding lift, suggesting the formation of a sensorimotor memory. Similar effects on force scaling are observed when the subsequent lift is performed with the hand opposite to the preceding lift. We used neuronavigated rTMS over the hand area of the dominant primary motor cortex to investigate its role in setting up sensorimotor memory. After ten lifts of a novel object with the dominant hand either rTMS or a period of motor rest commenced, until another set of lifts was performed with either the same or opposite hand. Compared to motor rest, rTMS caused underestimation of the object's weight when given 10 or 30s after the previous set of lifts, but overestimation of the object's weight when applied 60 or 120 s after the previous set of lifts, regardless of the hand performing the lift. Our interpretation of the data is that (a) the primary motor cortex is essential for setting up sensorimotor memory related to the mechanical object properties during manipulation and (b) rTMS can induce bidirectional changes of grip efficiency within the dynamics of sensorimotor integration.

  4. Interactive navigation-guided ophthalmic plastic surgery: navigation enabling of telescopes and their use in endoscopic lacrimal surgeries

    PubMed Central

    Ali, Mohammad Javed; Singh, Swati; Naik, Milind N; Kaliki, Swathi; Dave, Tarjani Vivek

    2016-01-01

    Purpose The aims of this study were to report the preliminary experience of using telescopes, which were enabled for navigation guidance, and their utility in complex endoscopic lacrimal surgeries. Methods Navigation enabling of the telescope was achieved by using the AxiEM™ malleable neuronavigation shunt stylet. Image-guided dacryolocalization was performed in five patients using the intraoperative image-guided StealthStation™ system in the electromagnetic mode. The “look ahead” protocol software was used to assist the surgeon in assessing the intraoperative geometric location of the endoscope and what lies ahead in real time. All patients underwent navigation-guided powered endoscopic dacryocystorhinostomy. The utility of uninterrupted navigation guidance throughout the surgery with the endoscope as the navigating tool was noted. Results Intraoperative geometric localization of the lacrimal sac and the nasolacrimal duct could be easily deciphered. Constant orientation of the lacrimal drainage system and the peri-lacrimal anatomy was possible without the need for repeated point localizations throughout the surgery. The “look ahead” features could accurately alert the surgeon of anatomical structures that exists at 5, 10 and 15 mm in front of the endoscope. Good securing of the shunt stylet with the telescope was found to be essential for constant and accurate navigation. Conclusion Navigation-enabled endoscopes provide the surgeon with the advantage of sustained stereotactic anatomical awareness at all times during the surgery. PMID:27920491

  5. Speaking of which: dissecting the neurocognitive network of language production in picture naming.

    PubMed

    Schuhmann, Teresa; Schiller, Niels O; Goebel, Rainer; Sack, Alexander Thomas

    2012-03-01

    The noninvasive methods of cognitive neuroscience offer new possibilities to study language. We used neuronavigated multisite transcranial magnetic stimulation (TMS) to determine the functional relevance of 1) the posterior part of left superior temporal gyrus (Wernicke's area), 2) a midportion of Broca's area (slightly posterior/superior to apex of vertical ascending ramus), and 3) the midsection of the left middle temporal gyrus (MTG), during overt picture naming. Our chronometric TMS design enabled us to chart the time points at which neural activity in each of these regions functionally contributes to overt speech production. Our findings demonstrate that the midsection of left MTG becomes functionally relevant at 225 ms after picture onset, followed by Broca's area at 300 ms and Wernicke's area at 400 ms. Interestingly, during this late time window, the left MTG shows a second peak of functional relevance. Each area thus contributed during the speech production process at different stages, suggesting distinct underlying functional roles within this complex multicomponential skill. These findings are discussed and framed in the context of psycholinguistic models of speech production according to which successful speaking relies on intact, spatiotemporally specific feed forward and recurrent feedback loops within a left-hemispheric fronto-temporal brain connectivity network.

  6. 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.

  7. Ventrolateral prefrontal cortex repetitive transcranial magnetic stimulation in the treatment of depersonalization disorder: A consecutive case series.

    PubMed

    Jay, Emma-Louise; Nestler, Steffen; Sierra, Mauricio; McClelland, Jessica; Kekic, Maria; David, Anthony S

    2016-06-30

    Case reports and an open trial have reported promising responses to repetitive transcranial magnetic stimulation (rTMS) to prefrontal and temporo-parietal sites in patients with depersonalization disorder (DPD). We recently showed that a single session of rTMS to the ventrolateral prefrontal cortex (VLPFC) was associated with a reduction in symptoms and increase in physiological arousal. Seven patients with medication-resistant DSM-IV DPD received up to 20 sessions of right-sided rTMS to the VLPFC for 10 weeks. Stimulation was guided using neuronavigation software based on participants' individual structural MRIs, and delivered at 110% of resting motor threshold. A session consisted of 1Hz repetitive TMS for 15min. The primary outcome measure was reduction in depersonalization symptoms on the Cambridge Depersonalization Scale (CDS). Secondary outcomes included scores on the Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI). 20 sessions of rTMS treatment to right VLPFC significantly reduced scores on the CDS by on average 44% (range 2-83.5%). Two patients could be classified as "full responders", four as "partial" and one a non-responder. Response usually occurred within the first 6 sessions. There were no significant adverse events. A randomized controlled clinical trial of VLPFC rTMS for DPD is warranted.

  8. Corticospinal tract mapping in children with ruptured arteriovenous malformations using functionally guided diffusion-tensor imaging.

    PubMed

    Ellis, Michael J; Rutka, James T; Kulkarni, Abhaya V; Dirks, Peter B; Widjaja, Elysa

    2012-05-01

    Arteriovenous malformations (AVMs) can lead to distortion or reorganization of functional brain anatomy, making localization of eloquent white matter tracts challenging. To improve the accuracy of corticospinal tract (CST) mapping, recent studies have examined the use of functional imaging techniques to help localize cortical motor activations and use these as seed points to reconstruct CSTs using diffusion-tensor imaging (DTI). The authors examined the role of pretreatment functionally guided DTI CST mapping in 3 children with ruptured AVMs. In 2 patients, magnetoencephalography motor activations were adjacent to the nidus and/or hemorrhagic cavity. However, in 1 child, functional MRI motor activations were detected in both hemispheres, suggestive of partial transfer of cortical motor function. In all children, quantitative analysis showed that fractional anisotropy values and fiber density indices were reduced in the CSTs of the hemisphere harboring the AVM compared with the unaffected side. In 2 children, CST caliber was slightly diminished, corresponding to no motor deficit in 1 patient and a temporary motor deficit in the other. In contrast, 1 child demonstrated marked reduction and displacement of the CSTs, correlating with severe motor deficit. Preoperative motor tractography data were loaded onto the intraoperative neuronavigation platform to guide complete resection of the AVM in 2 cases without permanent neurological deficits. These preliminary results confirm the feasibility of CST mapping in children with ruptured AVMs using functionally guided DTI tractography. Prospective studies are needed to assess the full value of this technique in the risk stratification, prognosis, and multimodality management of pediatric AVMs.

  9. A systematic pipeline for the objective comparison of whole-brain spectroscopic MRI with histology in biopsy specimens from grade III glioma.

    PubMed

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

    2016-06-01

    The diagnosis, prognosis, and management of patients with gliomas are largely dictated by the pathological analysis of tissue biopsied from a selected region within the lesion. However, due to the heterogeneous and infiltrative nature of gliomas, identifying the optimal region for biopsy with conventional magnetic resonance imaging (MRI) can be quite difficult. This is especially true for low grade gliomas, which often are non-enhancing tumors. To improve the management of patients with these tumors, the field of neuro-oncology requires an imaging modality that can specifically identify a tumor's most anaplastic/aggressive region(s) for biopsy targeting. The addition of metabolic mapping using spectroscopic MRI (sMRI) to supplement conventional MRI could improve biopsy targeting and, ultimately, diagnostic accuracy. Here, we describe a pipeline for the integration of state-of-the-art, high-resolution whole-brain 3D sMRI maps into a stereotactic neuronavigation system for guiding biopsies in gliomas with nonenhancing components. We also outline a machine-learning method for automated histology analysis that generates normalized, quantitative metrics describing tumor infiltration in immunohistochemically-stained tissue specimens. As a proof of concept, we describe the combination of these two techniques in a small cohort of grade III glioma patients. In this work, we aim to set forth a systematic pipeline to stimulate histopathology-image validation of advanced MRI techniques, such as sMRI.

  10. 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.

  11. Interactive navigation-guided ophthalmic plastic surgery: navigation enabling of telescopes and their use in endoscopic lacrimal surgeries.

    PubMed

    Ali, Mohammad Javed; Singh, Swati; Naik, Milind N; Kaliki, Swathi; Dave, Tarjani Vivek

    2016-01-01

    The aims of this study were to report the preliminary experience of using telescopes, which were enabled for navigation guidance, and their utility in complex endoscopic lacrimal surgeries. Navigation enabling of the telescope was achieved by using the AxiEM™ malleable neuronavigation shunt stylet. Image-guided dacryolocalization was performed in five patients using the intraoperative image-guided StealthStation™ system in the electromagnetic mode. The "look ahead" protocol software was used to assist the surgeon in assessing the intraoperative geometric location of the endoscope and what lies ahead in real time. All patients underwent navigation-guided powered endoscopic dacryocystorhinostomy. The utility of uninterrupted navigation guidance throughout the surgery with the endoscope as the navigating tool was noted. Intraoperative geometric localization of the lacrimal sac and the nasolacrimal duct could be easily deciphered. Constant orientation of the lacrimal drainage system and the peri-lacrimal anatomy was possible without the need for repeated point localizations throughout the surgery. The "look ahead" features could accurately alert the surgeon of anatomical structures that exists at 5, 10 and 15 mm in front of the endoscope. Good securing of the shunt stylet with the telescope was found to be essential for constant and accurate navigation. Navigation-enabled endoscopes provide the surgeon with the advantage of sustained stereotactic anatomical awareness at all times during the surgery.

  12. New coil positioning method for interleaved transcranial magnetic stimulation (TMS)/functional MRI (fMRI) and its validation in a motor cortex study.

    PubMed

    Moisa, Marius; Pohmann, Rolf; Ewald, Lars; Thielscher, Axel

    2009-01-01

    To develop and test a novel method for coil placement in interleaved transcranial magnetic stimulation (TMS)/functional MRI (fMRI) studies. Initially, a desired TMS coil position at the subject's head is recorded using a neuronavigation system. Subsequently, a custom-made holding device is used for coil placement inside the MR scanner. The parameters of the device corresponding to the prerecorded position are automatically determined from a fast structural image acquired directly before the experiment. The spatial accuracy of our method was verified on a phantom. Finally, in a study on five subjects, the coil was placed above the cortical representation of a hand muscle in M1 and the blood oxygenation level-dependent (BOLD) responses to short repetitive TMS (rTMS) trains were assessed using echo-planar imaging (EPI) recordings. The spatial accuracy of our method is in the range of 2.9 +/- 1.3 (SD) mm. Motor cortex stimulation resulted in robust BOLD activations in motor- and auditory related brain areas, with the activation in M1 being localized in the hand knob. We present a user-friendly method for TMS coil positioning in the MR scanner that exhibits good spatial accuracy and speeds up the setup of the experiment. The motor-cortex study proves the viability of the approach and validates our interleaved TMS/fMRI setup.

  13. A triangulation-based magnetic resonance image-guided method for transcranial magnetic stimulation coil positioning.

    PubMed

    Andoh, Jamila; Riviere, Denis; Mangin, Jean-François; Artiges, Eric; Cointepas, Yann; Grevent, David; Paillère-Martinot, Marie-Laure; Martinot, Jean-Luc; Cachia, Arnaud

    2009-07-01

    Transcranial magnetic stimulation (TMS) is currently used for cognitive studies and investigated as a treatment for psychiatric disorders. Because of the cortex variability, the coil positioning stage is difficult and should be improved by using individual neuroimaging data. Sophisticated and expensive neuronavigation systems have been developed to guide the coil to selected regions on the patient's magnetic resonance images (MRI). Our objective was to develop a triangulation-based MRI-guided method to position manually the TMS coil over the subject's head, using a cortical target derived from individual MR data. We evaluated both the spatial accuracy and the reproducibility of the method using functional MR activations of two different targets in the motor and parietal cortices. The accuracy of the MRI-guided method, assessed from the Euclidean distance (D(m)) between the thumb motor target and the coil position eliciting reproducible thumb motor-evoked potentials with TMS, was D(m) = 10 +/- 3 mm. The reproducibility of the method, evaluated across two different operators, was D(m) = 6.7 +/- 1.4 mm for the repositioning in the motor cortex and D(m) = 6.0 +/- 3.2 mm in the parietal cortex. This novel method could be used clinically to assist positioning of the TMS coil.

  14. Integrative Diffusion-Weighted Imaging and Radiogenomic Network Analysis of Glioblastoma multiforme

    PubMed Central

    Heiland, Dieter Henrik; Simon-Gabriel, Carl Philipp; Demerath, Theo; Haaker, Gerrit; Pfeifer, Dietmar; Kellner, Elias; Kiselev, Valerij G.; Staszewski, Ori; Urbach, Horst; Weyerbrock, Astrid; Mader, Irina

    2017-01-01

    In the past, changes of the Apparent Diffusion Coefficient in glioblastoma multiforme have been shown to be related to specific genes and described as being associated with survival. The purpose of this study was to investigate diffusion imaging parameters in combination with genome-wide expression data in order to obtain a comprehensive characterisation of the transcriptomic changes indicated by diffusion imaging parameters. Diffusion-weighted imaging, molecular and clinical data were collected prospectively in 21 patients. Before surgery, MRI diffusion metrics such as axial (AD), radial (RD), mean diffusivity (MD) and fractional anisotropy (FA) were assessed from the contrast enhancing tumour regions. Intraoperatively, tissue was sampled from the same areas using neuronavigation. Transcriptional data of the tissue samples was analysed by Weighted Gene Co-Expression Network Analysis (WGCNA) thus classifying genes into modules based on their network-based affiliations. Subsequent Gene Set Enrichment Analysis (GSEA) identified biological functions or pathways of the expression modules. Network analysis showed a strong association between FA and epithelial-to-mesenchymal-transition (EMT) pathway activation. Also, patients with high FA had a worse clinical outcome. MD correlated with neural function related genes and patients with high MD values had longer overall survival. In conclusion, FA and MD are associated with distinct molecular patterns and opposed clinical outcomes. PMID:28266556

  15. Attenuation of N2 amplitude of laser-evoked potentials by theta burst stimulation of primary somatosensory cortex.

    PubMed

    Poreisz, Csaba; Antal, Andrea; Boros, Klára; Brepohl, Nadine; Csifcsák, Gábor; Paulus, Walter

    2008-03-01

    Theta burst stimulation (TBS) is a special repetitive transcranial magnetic stimulation (rTMS) paradigm, where bursts of low-intensity stimuli are applied in the theta frequency. The aim of this study was to investigate the effect of neuronavigated TBS over primary somatosensory cortex (SI) on laser-evoked potentials (LEPs) and acute pain perception induced with Tm : YAG laser stimulation. The amplitude changes of the N1, N2, and P2 components of LEPs and related subjective pain rating scores of 12 healthy subjects were analyzed prior to and following continuous TBS (cTBS), intermittent TBS (iTBS), intermediate TBS (imTBS), and sham stimulation. Our results demonstrate that all active TBS paradigms significantly diminished the amplitude of the N2 component, when the hand contralateral to the site of TBS was laser-stimulated. Sham stimulation condition had no significant effect. The subjective pain perception also decreased during the experimental sessions, but did not differ significantly from the sham stimulation condition. The main finding of our study is that TBS over SI diminished the amplitude of the N2 component evoked from the contralateral side without any significant analgesic effects. Furthermore, imTBS produced responses similar to those observed by other forms of TBS induced excitability changes in the SI.

  16. A Pipeline for 3D Multimodality Image Integration and Computer-assisted Planning in Epilepsy Surgery.

    PubMed

    Nowell, Mark; Rodionov, Roman; Zombori, Gergely; Sparks, Rachel; Rizzi, Michele; Ourselin, Sebastien; Miserocchi, Anna; McEvoy, Andrew; Duncan, John

    2016-05-20

    Epilepsy surgery is challenging and the use of 3D multimodality image integration (3DMMI) to aid presurgical planning is well-established. Multimodality image integration can be technically demanding, and is underutilised in clinical practice. We have developed a single software platform for image integration, 3D visualization and surgical planning. Here, our pipeline is described in step-by-step fashion, starting with image acquisition, proceeding through image co-registration, manual segmentation, brain and vessel extraction, 3D visualization and manual planning of stereoEEG (SEEG) implantations. With dissemination of the software this pipeline can be reproduced in other centres, allowing other groups to benefit from 3DMMI. We also describe the use of an automated, multi-trajectory planner to generate stereoEEG implantation plans. Preliminary studies suggest this is a rapid, safe and efficacious adjunct for planning SEEG implantations. Finally, a simple solution for the export of plans and models to commercial neuronavigation systems for implementation of plans in the operating theater is described. This software is a valuable tool that can support clinical decision making throughout the epilepsy surgery pathway.

  17. A Pipeline for 3D Multimodality Image Integration and Computer-assisted Planning in Epilepsy Surgery

    PubMed Central

    Nowell, Mark; Rodionov, Roman; Zombori, Gergely; Sparks, Rachel; Rizzi, Michele; Ourselin, Sebastien; Miserocchi, Anna; McEvoy, Andrew; Duncan, John

    2016-01-01

    Epilepsy surgery is challenging and the use of 3D multimodality image integration (3DMMI) to aid presurgical planning is well-established. Multimodality image integration can be technically demanding, and is underutilised in clinical practice. We have developed a single software platform for image integration, 3D visualization and surgical planning. Here, our pipeline is described in step-by-step fashion, starting with image acquisition, proceeding through image co-registration, manual segmentation, brain and vessel extraction, 3D visualization and manual planning of stereoEEG (SEEG) implantations. With dissemination of the software this pipeline can be reproduced in other centres, allowing other groups to benefit from 3DMMI. We also describe the use of an automated, multi-trajectory planner to generate stereoEEG implantation plans. Preliminary studies suggest this is a rapid, safe and efficacious adjunct for planning SEEG implantations. Finally, a simple solution for the export of plans and models to commercial neuronavigation systems for implementation of plans in the operating theater is described. This software is a valuable tool that can support clinical decision making throughout the epilepsy surgery pathway. PMID:27286266

  18. 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.

  19. Purely endoscopic removal of a parasagittal/falx meningioma.

    PubMed

    Spektor, Sergey; Margolin, Emil; Eliashar, Ron; Moscovici, Samuel

    2016-03-01

    Endoscopic techniques are an integral part of the neurosurgical armamentarium with a growing list of indications. We describe the purely endoscopic removal of an atypical parasagittal meningioma in a patient who could not undergo standard craniotomy due to severe scalp atrophy following childhood irradiation for tinea capitis. A 68-year-old man in good general health presented with a parasagittal meningioma that recurred following subtotal removal and adjuvant fractionated stereotactic radiosurgery (FSR). The scalp above the tumor location was very diseased and precluded a regular craniotomy for tumor removal. A 4-cm craniotomy was made in the midline forehead, where the skin was normal. A rigid endoscope was advanced under neuronavigation through the interhemispheric fissure, which provided good access with limited retraction, until the tumor was encountered at a depth of 7-8 cm. Two surgeons performed the surgery using a "four-hands technique". The tumor was removed and the insertion area was resected and coagulated. The surgery was uneventful, with no coagulation or transection of major veins. A subtotal resection was achieved, and the patient recovered with no neurological deficit. Safe resection of parasagittal meningiomas with a purely endoscopic technique is feasible. This option needs further exploration as an alternative strategy in patients with severely atrophic scalp skin that greatly increases the risk of significant healing complications with calvarian craniotomy.

  20. Microsurgical Anatomy of the Internal Acoustic Meatus as Seen Using the Retrosigmoid Approach.

    PubMed

    Scerrati, Alba; Lee, Jung-Shun; Zhang, Jun; Ammirati, Mario

    2016-06-01

    To show via a retrosigmoid approach the bony labyrinth anatomy and its relationship with the internal acoustic meatus so as to provide guidelines for a safer drilling to the fundus using this approach. Few studies deal with the complex anatomy of petrous bone structures as observed by a retrosigmoid approach. Ten retrosigmoid approaches were performed bilaterally on five fresh cadaveric heads. Afterward high-resolution computed tomographic scans were obtained. Measurements of landmarks and distances between important topographic structures of the pyramid were obtained on its surface using a navigation system. Semicircular canals, vestibular aqueduct, and internal acoustic meatus were dissected to show their anatomy and relationships. The anatomy of the inner ear structures was shown. Opening of the internal acoustic meatus was accomplished without injury to the labyrinth in 9 out of 10 sides. The distance between the drilled bone of the internal acoustic meatus and the vestibule was calculated on the postoperative computed tomographic scan. The mean value was 1.43 mm (SD, 0.30 mm; range, 1.0-1.8 mm). A better knowledge of the anatomy of the semicircular canals and of the vestibular aqueduct as observed by a retrosigmoid approach, together with their relationships to the fundus and other petrous bone landmarks, can be useful to get a general orientation in acoustic neuroma surgery. Using this information together with the neuronavigation, we were able to successfully open the internal acoustic meatus without entering labyrinthine structures in 90% of the study dissections.

  1. 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.

  2. Pineal cyst apoplexy: case report and review of the literature.

    PubMed

    Patel, Akash J; Fuller, Gregory N; Wildrick, David M; Sawaya, Raymond

    2005-11-01

    Although most pineal cysts are clinically benign and asymptomatic, some can become symptomatic. Of the various symptomatic presentations, apoplexy is the rarest and most ill-defined. A comprehensive search of publications in the English language yielded 18 cases of pineal cyst apoplexy. We reviewed the literature to compare symptomatology and management strategies and their outcomes. A 29-year-old woman with a 1-month history of headaches presented with an acute worsening of her symptoms with a severe occipital headache and trouble focusing when reading. Her neurological examination was otherwise normal. Magnetic resonance imaging showed pineal cyst apoplexy and accompanying hydrocephalus. A left paramedian craniotomy with a transcallosal, transchoroidal approach using an intraoperative neuronavigation system was used to resect a pineal cyst. Postoperative imaging showed complete removal of the cyst and resolution of the hydrocephalus. Follow-up imaging at 12 months demonstrated no evidence of recurrence or any hydrocephalus. The patient has remained asymptomatic for 18 months. Pineal cyst apoplexy should always be considered when following a patient with a pineal cyst that becomes symptomatic. The most common symptom was severe headache of sudden onset or acute worsening. Other signs of hydrocephalus may or may not be present. Magnetic resonance imaging is essential to making a diagnosis. Although we believe that surgical resection is the most effective approach because it minimizes the risk for recurrence and complication, stereotactic aspiration has been used successfully to treat this condition.

  3. 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

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

    PubMed

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

    2011-01-01

    To observe interdepartmental variation in the availability of resources and academic activities within the various neurosurgery programs of Pakistan. 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. 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. 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.

  5. Transcranial Clot Lysis Using High Intensity Focused Ultrasound

    NASA Astrophysics Data System (ADS)

    Hölscher, Thilo; Zadicario, Eyal; Fisher, David J.; Bradley, William G.

    2010-03-01

    Stroke is the third common cause of death worldwide. The majority of strokes are caused by sudden vessel occlusion, due to a blood clot. Vessel recanalization is the primary goal of all acute stroke treatment strategies. Initial data using ultrasound in combination with a therapeutic agent for clot lysis in stroke are promising. However, sound absorption and defocusing of the ultrasound beam occur during transskull insonation, limiting the efficiency of this approach to high extent. Using a transskull High Intensity Focused Ultrasound (HIFU) head system we were able to lyse blood clots within seconds and in absence of further lytic agents. We could show that any correction for the distortion might be negligible to focus the ultrasound beam after transskull insonation. The use of transskull HIFU for immediate clot lysis in the human brain without the need of further drugs and disregarding individual skull bone characteristics could become a successful strategy in early stroke treatment. Using magnetic resonance tomography for neuronavigation MRI Guided High Intensity Focused Ultrasound has the potential to open new avenues for therapeutic applications in the brain including Stroke, Intracranial Hemorrhages, Braintumors, Neurodegenerative Diseases, Thalamic Pain, BBB opening, and local drug delivery. First results in transcranial clot lysis will be presented in this paper.

  6. Attenuation of N2 amplitude of laser-evoked potentials by theta burst stimulation of primary somatosensory cortex

    PubMed Central

    Antal, Andrea; Boros, Klára; Brepohl, Nadine; Csifcsák, Gábor; Paulus, Walter

    2007-01-01

    Theta burst stimulation (TBS) is a special repetitive transcranial magnetic stimulation (rTMS) paradigm, where bursts of low-intensity stimuli are applied in the theta frequency. The aim of this study was to investigate the effect of neuronavigated TBS over primary somatosensory cortex (SI) on laser-evoked potentials (LEPs) and acute pain perception induced with Tm : YAG laser stimulation. The amplitude changes of the N1, N2, and P2 components of LEPs and related subjective pain rating scores of 12 healthy subjects were analyzed prior to and following continuous TBS (cTBS), intermittent TBS (iTBS), intermediate TBS (imTBS), and sham stimulation. Our results demonstrate that all active TBS paradigms significantly diminished the amplitude of the N2 component, when the hand contralateral to the site of TBS was laser-stimulated. Sham stimulation condition had no significant effect. The subjective pain perception also decreased during the experimental sessions, but did not differ significantly from the sham stimulation condition. The main finding of our study is that TBS over SI diminished the amplitude of the N2 component evoked from the contralateral side without any significant analgesic effects. Furthermore, imTBS produced responses similar to those observed by other forms of TBS induced excitability changes in the SI. PMID:18043910

  7. Brain involvement by leprosy presenting as a frontal cystic lesion.

    PubMed

    Lee, Kyung-Hwa; Moon, Kyung-Sub; Yun, Sook Jung; Won, Young Ho; Lee, Jae-Hyuk; Lee, Min-Cheol; Jung, Shin

    2014-07-01

    Leprosy has a predilection for peripheral nerves and is not considered to involve the CNS. The idea that the CNS is exempt from Mycobacterium leprae bacilli has been suspected from a clinical perspective or CSF study in leprosy patients. However, there has been no direct evidence for CNS involvement by leprosy in a living patient. To the best of the authors' knowledge, the present case is the first report providing histopathological and molecular evidence for CNS involvement by leprosy in a living patient. Brain MRI revealed a 2-cm cystic lesion in the right frontal lobe of the patient. The medical history revealed that the patient had been receiving multidrug therapy for borderline lepromatous leprosy. Neuronavigation-guided craniotomy and lesion removal were performed due to a presumptive diagnosis of low-grade glioma. The brain specimen demonstrated variably thickened blood vessels and densely scattered foamy macrophages in the perivascular spaces and parenchymal stroma. Fite acid-fast stain displayed red granular inclusions that were suggestive for fragmented M. leprae. M. leprae-specific nested polymerase chain reaction amplification showed positive bands, and DNA sequencing also demonstrated homology with the M. leprae genome. This case supports the notion that M. leprae can involve the cerebral cortex regardless of cranial nerve engagement.

  8. Path to the Interpeduncular Fossa: Anatomical Comparison of Endoscopic-Assisted versus Standard Subtemporal Approach

    PubMed Central

    Lamki, Tariq; Salma, Asem; Baidya, Nishanta; Ammirati, Mario

    2012-01-01

    Objective The aim of this study was to assess the assumed advantage of endoscopic assistance to the standard subtemporal approach. The idea was to measure qualitatively and quantitatively visibility versus operability. Design We performed eight subtemporal dissections on four cadaver heads. Our dissections integrated an operating microscope, endoscope, and neuronavigation. Comparison was made between visibility and operability afforded by the microscope alone or by the microscope–endoscope combination. Visibility was recorded as complete or incomplete and was quantified for key structures using linear measurements taken by the navigation system. Operability was determined by whichever maneuvers could be safely and comfortably accomplished in the space afforded. Results From our survey, the structures whose visibility most benefitted from the addition of the endoscope include: contralateral third nerve, posterior perforated substance, mammillary bodies, and contralateral superior cerebellar artery. With regard to quantitative evaluation, we found increased visibility of both basilar artery and posterior cerebral artery. With regard to the operability, no objective advantage was afforded by the addition of the endoscope. Subjectively, the maneuvers were easier to perform while using the endoscope. Conclusion Using the endoscope as an assistance tool during conducting classical subtemporal approach can help in overcome a lot of the classical subtemporal approach limitations. PMID:23905002

  9. 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.

  10. TMS reveals a direct influence of spinal projections from human SMAp on precise force production.

    PubMed

    Entakli, Jonathan; Bonnard, Mireille; Chen, Sophie; Berton, Eric; De Graaf, Jozina B

    2014-01-01

    The corticospinal (CS) system plays an important role in fine motor control, especially in precision grip tasks. Although the primary motor cortex (M1) is the main source of the CS projections, other projections have been found, especially from the supplementary motor area proper (SMAp). To study the characteristics of these CS projections from SMAp, we compared muscle responses of an intrinsic hand muscle (FDI) evoked by stimulation of human M1 and SMAp during an isometric static low-force control task. Subjects were instructed to maintain a small cursor on a target force curve by applying a pressure with their right precision grip on a force sensor. Neuronavigated transcranial magnetic stimulation was used to stimulate either left M1 or left SMAp with equal induced electric field values at the defined cortical targets. The results show that the SMAp stimulation evokes reproducible muscle responses with similar latencies and amplitudes as M1 stimulation, and with a clear and significant shorter silent period. These results suggest that (i) CS projections from human SMAp are as rapid and efficient as those from M1, (ii) CS projections from SMAp are directly involved in control of the excitability of spinal motoneurons and (iii) SMAp has a different intracortical inhibitory circuitry. We conclude that human SMAp and M1 both have direct influence on force production during fine manual motor tasks. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  11. Cerebellar brain inhibition in the target and surround muscles during voluntary tonic activation

    PubMed Central

    Panyakaew, Pattamon; Cho, Hyun Joo; Srivanitchapoom, Prachaya; Popa, Traian; Wu, Tianxia; Hallett, Mark

    2016-01-01

    Motor surround inhibition is the neural mechanism that selectively favors the contraction of target muscles and inhibits nearby muscles to prevent unwanted movements. This inhibition was previously reported at the onset of a movement, but not during a tonic contraction. Cerebellar brain inhibition (CBI) is reduced in active muscles during tonic activation; however, it has not been studied in the surround muscles. CBI was evaluated in the first dorsal interosseus (FDI) as the target muscle, and the abductor digiti minimi (ADM), flexor carpi radialis (FCR), and extensor carpi radialis (ECR) as surround muscles during rest and tonic activation of FDI in fourteen subjects. Cerebellar stimulation was performed under MRI-guided neuronavigation targeting lobule VIII of the cerebellar hemisphere. Stimulus intensities for cerebellar stimulation were based on the resting motor cortex threshold (RMT) and adjusted for the depth difference between the cerebellar and motor cortices. We used 90% to 120% of adjusted RMT as the conditioning stimulus intensity during rest. The intensity that generated the best CBI at rest in the FDI was selected for use during tonic activation. During selective tonic activation of FDI, CBI was significantly reduced only for FDI but not for the surround muscles. Unconditioned MEP sizes were increased in all muscles during FDI tonic activation compared to rest, despite background EMG activity increasing only for the FDI. Our study suggests that the cerebellum may play an important role in selective tonic finger movement by reducing its inhibition in the motor cortex only for the relevant agonist muscle. PMID:26900871

  12. 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.

  13. The Shape of the Foramen Ovale: A Visualization Aid for Cannulation Procedures.

    PubMed

    Zdilla, Matthew J; Fijalkowski, Kristen M

    2017-03-01

    Several neurosurgical procedures, including rhizotomy for the management of trigeminal neuralgia, cannulate the foramen ovale (FO) to access intracranial structures. Cannulation procedures, including those utilizing neuronavigational technology, are occasionally complicated by anatomical variation of the FO, sometimes resulting in miscannulation and subsequent adverse events. The FO, while commonly thought of as oval-shaped, has also been described as "almond," "banana," "D shape," "pear," and "triangular." Because of the importance of the FO in neurosurgical procedures and the misunderstanding of FO shape, the aim of this study is to objectively describe the shape of the FO and its most likely shape variation. A total of 211 FO were evaluated by geometric morphometric analysis. A consensus shape is presented for the FO. No significant difference was found between the shapes of left- and right-sided FO. The most likely shape variation of the FO occurs as an inverse relationship between the anteromedial-posterolateral and anterolateral-posteromedial aspects of the foramen. The capacity to visualize the average FO shape and understand the most likely shape variance, as illustrated by this report, will aid neurosurgeons in their approach to procedures requiring cannulation of the FO.

  14. Motor Cortex Stimulation in Parkinson's Disease

    PubMed Central

    De Rose, Marisa; Guzzi, Giusy; Bosco, Domenico; Romano, Mary; Lavano, Serena Marianna; Plastino, Massimiliano; Volpentesta, Giorgio; Marotta, Rosa; Lavano, Angelo

    2012-01-01

    Motor Cortex Stimulation (MCS) is less efficacious than Deep Brain Stimulation (DBS) in Parkinson's disease. However, it might be proposed to patients excluded from DBS or unresponsive to DBS. Ten patients with advanced PD underwent unilateral MCS contralaterally to the worst clinical side. A plate electrode was positioned over the motor cortex in the epidural space through single burr hole after identification of the area with neuronavigation and neurophysiological tests. Clinical assessment was performed by total UPDRS, UPDRS III total, UPDRS III-items 27–31, UPDRS IV, and UPDRS II before implantation in off-medication and on-medication states and after surgery at 1, 3, 6, 12, 18, 24, and 36 months in on-medication/on-stimulation and off-medication/on-stimulation states. We assessed changes of quality of life, throughout the Parkinson's disease quality of life scale (PDQoL-39), and the dose of anti-Parkinson's disease medications, throughout the Ldopa equivalent daily dose (LEDD). During off-medication state, we observed moderate and transitory reduction of total UPDRS and UPDRS total scores and significant and long-lasting improvement in UPDRS III items 27–31 score for axial symptoms. There was marked reduction of UPDRS IV score and LEDD. PDQL-39 improvement was also significant. No important complications and adverse events occurred. PMID:23213520

  15. Primary Central Nervous System Lymphoma: A Critical Review of the Role of Surgery for Resection

    PubMed Central

    Yun, Jonathan; Iwamoto, Fabio M.; Sonabend, Adam M.

    2016-01-01

    Background Primary central nervous system lymphomas (PCNSL) are rare CNS tumors that carry a poor prognosis, with most patients suffering recurrence. Progress has been made in the treatment of this pathology, notably with the widespread use of systemic high dose methotrexate. However, unlike most other malignant CNS neoplasms, surgery for cytoreduction is not routinely performed for this disease, mainly as a result of negative experiences decades ago. Since these studies were published, the availability of intraoperative monitoring, MR imaging and neuro-navigation as well as surgical adjuncts such as fluorescence- guided resection have greatly improved the safety of intracranial procedures. More recent data is suggestive of a potential survival benefit for resection of single PCNSL lesions when patients are subsequently treated with modern regimen high-dose methotrexate, yet this evidence is limited, and should be interpreted conservatively. Methods and findings A systematic review of the literature was performed to identify trials evaluating surgical options for the treatment of PCNSL. Conclusion In this review, we provide a critical overview of the evidence favoring and discouraging resection for PCNSL. This literature suffers from several biases and limitations that must be considered in the context of the extrapolation of this literature into clinical decision-making. PMID:28239600

  16. Semi-automated Volumetric and Morphological Assessment of Glioblastoma Resection with Fluorescence-Guided Surgery

    PubMed Central

    Cordova, J. Scott; Gurbani, Saumya S.; Holder, Chad A.; Olson, Jeffrey J.; Schreibmann, Eduard; Shi, Ran; Guo, Ying; Shu, Hui-Kuo G.; Shim, Hyunsuk; Hadjipanayis, Costas G.

    2016-01-01

    Purpose Glioblastoma (GBM) neurosurgical resection relies on contrast-enhanced MRI-based neuronavigation. However, it is well-known that infiltrating tumor extends beyond contrast enhancement. Fluorescence-guided surgery (FGS) using 5-aminolevulinic acid (5-ALA) was evaluated to improve extent of resection (EOR) of GBMs. Pre-operative morphological tumor metrics were also assessed. Procedures Thirty patients from a Phase II trial evaluating 5-ALA FGS in newly diagnosed GBM were assessed. Tumors were segmented pre-operatively to assess morphological features as well as post-operatively to evaluate EOR and residual tumor volume (RTV). Results Median EOR and RTV were 94.3% and 0.821 cm3, respectively. Pre-operative surface area to volume ratio and RTV were significantly associated with overall survival, even when controlling for the known survival confounders. Conclusions This study supports claims that 5-ALA FGS is helpful at decreasing tumor burden and prolonging survival in GBM. Moreover, morphological indices are shown to impact both resection and patient survival. PMID:26463215

  17. Motor cortex stimulation in Parkinson's disease.

    PubMed

    De Rose, Marisa; Guzzi, Giusy; Bosco, Domenico; Romano, Mary; Lavano, Serena Marianna; Plastino, Massimiliano; Volpentesta, Giorgio; Marotta, Rosa; Lavano, Angelo

    2012-01-01

    Motor Cortex Stimulation (MCS) is less efficacious than Deep Brain Stimulation (DBS) in Parkinson's disease. However, it might be proposed to patients excluded from DBS or unresponsive to DBS. Ten patients with advanced PD underwent unilateral MCS contralaterally to the worst clinical side. A plate electrode was positioned over the motor cortex in the epidural space through single burr hole after identification of the area with neuronavigation and neurophysiological tests. Clinical assessment was performed by total UPDRS, UPDRS III total, UPDRS III-items 27-31, UPDRS IV, and UPDRS II before implantation in off-medication and on-medication states and after surgery at 1, 3, 6, 12, 18, 24, and 36 months in on-medication/on-stimulation and off-medication/on-stimulation states. We assessed changes of quality of life, throughout the Parkinson's disease quality of life scale (PDQoL-39), and the dose of anti-Parkinson's disease medications, throughout the Ldopa equivalent daily dose (LEDD). During off-medication state, we observed moderate and transitory reduction of total UPDRS and UPDRS total scores and significant and long-lasting improvement in UPDRS III items 27-31 score for axial symptoms. There was marked reduction of UPDRS IV score and LEDD. PDQL-39 improvement was also significant. No important complications and adverse events occurred.

  18. Contributions of the PPC to Online Control of Visually Guided Reaching Movements Assessed with fMRI-Guided TMS

    PubMed Central

    Bresciani, Jean-Pierre; Peer, Angelika; Bülthoff, Heinrich H.; Thielscher, Axel

    2011-01-01

    The posterior parietal cortex (PPC) plays an important role in controlling voluntary movements by continuously integrating sensory information about body state and the environment. We tested which subregions of the PPC contribute to the processing of target- and body-related visual information while reaching for an object, using a reaching paradigm with 2 types of visual perturbation: displacement of the visual target and displacement of the visual feedback about the hand position. Initially, functional magnetic resonance imaging (fMRI) was used to localize putative target areas involved in online corrections of movements in response to perturbations. The causal contribution of these areas to online correction was tested in subsequent neuronavigated transcranial magnetic stimulation (TMS) experiments. Robust TMS effects occurred at distinct anatomical sites along the anterior intraparietal sulcus (aIPS) and the anterior part of the supramarginal gyrus for both perturbations. TMS over neighboring sites did not affect online control. Our results support the hypothesis that the aIPS is more generally involved in visually guided control of movements, independent of body effectors and nature of the visual information. Furthermore, they suggest that the human network of PPC subregions controlling goal-directed visuomotor processes extends more inferiorly than previously thought. Our results also point toward a good spatial specificity of the TMS effects. PMID:21084453

  19. [Efficacy analysis of endoscopic endonasal transsphenoidal surgery for recurrent or regrowing pituitary adenomas].

    PubMed

    Xue, Yajun; Zhao, Yaodong; Cui, Daming; Wang, Ke; Shen, Zhaoli; Shen, Rui; Lou, Meiqing

    2015-02-03

    To analyze the safety and efficacy of surgical removal of recurrent or regrowing pituitary adenomas by endoscopic endonasal transsphenoidal approach. The clinical data were retrospectively reviewed for 28 patients undergoing endoscopic endonasal transsphenoidal surgery for recurrent or regrowing pituitary adenomas between April 2010 and December 2013. There were 9 males and 19 females with a mean age of 44. 2 (11 - 73) years. The maximal tumor diameter ranged from 2. 1 to 6.9 cm. The Knosp grades were 1 -2 (n = 11), 3 (n =8) and 4 (n =9). Fifteen tumors were endocrinically functional and the remainder endocrinically nonfunctional. All operations were performed with an assistance of intraoperative neuronavigation. Neuro-ophthalmological, neuroimaging and endocrinological results were followed up postoperatively. And surgical outcomes and risk factors were analyzed for incomplete tumor resection in previous operations. The mean follow-up period was 19. 1 (3 - 45) months. Gross total resection(n = 18, 64. 3%), subtotal resection(n = 6, 21. 4%) and partial resection(n = 4, 14. 3%) were achieved. Postoperatively, visual acuity improved in 11 patients (73. 3%) and 6 patients (40. 0%) showed endocrine remission. Qne patient had short-term postoperative leakage of cerebrospinal fluid (CSF). Endoscopic endonasal transsphenoidal surgery is both safe and effective for recurrent or regrowing pituitary adenomas.

  20. Endoscopic endonasal skull base surgery: past, present and future.

    PubMed

    Castelnuovo, Paolo; Dallan, Iacopo; Battaglia, Paolo; Bignami, Maurizio

    2010-05-01

    Endoscopic techniques have undergone tremendous advancement in the past years. From the management of phlogistic pathologies, we have learned to manage skull base lesions and even selected intracranial diseases. Current anatomical knowledge plus computer-aided surgery has enabled surgeons to remove large lesions in the paranasal sinuses extending beyond the boundaries of the sinuses themselves. In this sense, management of benign diseases via endoscopic routes is nowadays well accepted whilst the role of endoscopic techniques in sinonasal malignancies is still under investigation. Nowadays, it is possible to tackle different pathologies placed not only in the ventral skull base, but also extended laterally (infratemporal fossa and petrous apex) and even, in really selected cases, within the orbit. The ability to resect and reconstruct has improved significantly. At the moment, the improvement in surgical techniques, like the four-handed technique, has rendered endoscopic procedures capable of managing complex pathologies, according the same surgical principles of the open approaches. From now onwards, frameless neuronavigation, modular approaches, intraoperative imaging systems and robotic surgery are and will be an increasingly important part of endonasal surgery, and they will be overtaken by further evolution.

  1. 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.

  2. Intracranial endoscopy.

    PubMed

    Schroeder, H W; Gaab, M R

    1999-04-15

    The authors' intention is to reduce the invasiveness of intracranial procedures while avoiding traumatization of brain tissue, to decrease the risk of neurological and mental deficits. Intracranial endoscopy is a minimally invasive technique that provides rapid access to the target via small burr holes without the need for brain retraction. Craniotomy as well as microsurgical brain splitting and dissection can often be avoided. Furthermore, because obstructed cerebrospinal fluid pathways can be physiologically restored, the need for shunt placement is eliminated. The ventricular system and subarachnoid spaces provide ideal conditions for the use of an endoscope. Therefore, a variety of disorders, such as hydrocephalus, small intraventricular lesions, and arachnoid and parenchymal cysts can be effectively treated using endoscopic techniques. With the aid of special instruments, laser fibers, and bipolar diathermy, even highly vascularized lesions such as cavernomas may be treated. Moreover, during standard microsurgical procedures, the endoscopic view may provide valuable additional information ("looking around a corner") about the individual anatomy that is not visible with the microscope. In transsphenoidal pituitary surgery, transseptal dissection can be avoided if an endonasal approach is taken. In the depth of the intrasellar space, the extent of tumor removal can be more accurately controlled, especially in larger tumors with para- and suprasellar growth. The combined use of endoscopes and computerized neuronavigation systems increases the accuracy of the approach and provides real-time control of the endoscope tip position and approach trajectory. In the future, the indications for neuroendoscopy will certainly expand with improved technical equipment.

  3. 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

  4. Differentiation of motor cortical representation of hand muscles by navigated mapping of optimal TMS current directions in healthy subjects

    PubMed Central

    Bashir, Shahid; Perez, Jennifer; Horvath, Jared Cooney; Pascual-Leone, Alvaro

    2013-01-01

    The precision of navigated transcranial magnetic stimulation (TMS) to map the human primary motor cortex may be effected the direction of TMS-induced current in the brain as determined by the orientation of the stimulation coil. In this study, we investigated the effect of current directionality on motor output mapping using navigated brain stimulation (NBS). Our goal was to determine the optimal coil orientation (and, thus, induced brain current) to activate hand musculature representations relative to each subject’s unique neuroanatomical landmarks. We studied motor output maps for the first dorsal interosseous (FDI), abductor pollicis brevis (APB), and abductor digiti minimi (ADM) muscles in 10 normal volunteers. Monopolar current pulses were delivered through a figure-of-eight shaped TMS coil and motor evoked potentials (MEPs) were recorded using electromyography (EMG). At each targeted brain region, we systematically rotated the TMS coil to determine the direction of induced current in the brain for induction of the largest MEPs. These optimal current directions were expressed as an angle relative to each subject’s central sulcus. Consistency of the optimal current direction was assessed by repeating the entire mapping procedure on two different occasions across subjects. We demonstrate that systematic optimization of current direction as guided by MRI based neuronavigation improves the resolution of cortical output motor mapping with TMS. PMID:23912579

  5. 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

  6. 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.

  7. [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.

  8. Marker-CT assisted surgery using household key ring: A simple substitute to frameless stereotaxy for developing countries.

    PubMed

    Dhandapani, Sivashanmugam; Singh, Harnarayan

    2014-01-01

    Operative localization systems such as stereotactic frames and neuronavigation are prohibitively expensive to be of use in many centers in developing countries. Here, we present a modified version of marker-computed tomography (CT) assisted technique using a household key ring, which can be performed in any operative set-up lacking modern amenities. For a patient who presents with left posterior frontal lesion, the approximate entry point for the shortest and perpendicular trajectory to the lesion is marked on the scalp using a household key ring and fixed in place. Helical CT is obtained and reconstruction performed in two planes perpendicular to the ring and mutually perpendicular to each other. Based on the measurements of the lesion in relation to the radiologic pointers of the ring, and the location of the corrected entry point with respect to the center of the ring, the shortest perpendicular depth of approach is determined. Freehand technique perpendicular to the surface at the predetermined entry point and depth is employed for the surgical approach. The advantages of key ring over other markers are its simplicity, conformity to the shape of the head, and paucity of artifacts in CT. The relatively effortless estimation and three-dimensional visual impression renders this method easy enough to be employed anywhere for the operative localization of superficial intracranial lesions both for biopsy as well as resection.

  9. Image-guided transsylvian, transinsular approach for insular cavernous angiomas.

    PubMed

    Tirakotai, Wuttipong; Sure, Ulrich; Benes, Ludwig; Krischek, Boris; Bien, Siegfried; Bertalanffy, Helmut

    2007-07-01

    Surgical treatment of cavernomas arising in the insula is especially challenging because of the proximity to the internal capsule and lenticulostriate arteries. We present our technique of image guidance for operations on insular cavernomas and assess its clinical usefulness. Between 1997 and 2003, with the guidance of a frameless stereotactic system (BrainLab AG, Munich, Germany), we operated on eight patients who harbored an insular cavernoma. Neuronavigation was used for 1) accurate planning of the craniotomy, 2) identification of the distal sylvian fissure, and, finally, 3) finding the exact site for insular corticotomy. Postoperative clinical and neuroradiological evaluations were performed in each patient. The navigation system worked properly in all eight neurosurgical patients. Exact planning of the approach and determination of the ideal trajectory of dissection toward the cavernoma was possible in every patient. All cavernomas were readily identified and completely removed by use of microsurgical techniques. No surgical complications occurred, and the postoperative course was uneventful in all patients. Image guidance during surgery for insular cavernomas provides high accuracy for lesion targeting and permits excellent anatomic orientation. Accordingly, safe exposure can be obtained because of a tailored dissection of the sylvian fissure and minimal insular corticotomy.

  10. The role of neuroendoscopy in the management of solid or solid-cystic intra- and periventricular tumours.

    PubMed

    Tirakotai, Wuttipong; Hellwig, Dieter; Bertalanffy, Helmut; Riegel, Thomas

    2007-06-01

    The purpose of this study was to describe the surgical strategies of neuroendoscopic treatment in patients with solid or solid-cystic peri- and intraventricular tumours. Analysis of the postoperative histopathology and complication of neuroendoscopic interventions was also performed. A number of intracranial tumours do not ultimately require aggressive surgical intervention. Either definite or palliative treatment for the intra- and periventricular lesions could be accomplished using various neuroendoscopic techniques, depending on the histopathological diagnosis and aim of therapeutic intervention. Between 1994 and 2004, 46 patients with newly diagnosed solid or solid-cystic peri- and intraventricular tumours underwent neuroendoscopic procedures Twenty patients had associated hydrocephalus requiring the cerebrospinal fluid diversion procedures. Since 1997, neuronavigation has been applied to selected cases. Obstructive hydrocephalus was treated sufficiently by endoscopic third ventriculostomy or endoscopic stent placement. Partial or total extirpation of solid tumour was achieved in four cases. The majority of pathological examinations revealed astrocytoma (23), craniopharygioma (7) and metastasis (2). Subsequent mode of treatment such as chemotherapy, radiation therapy or microscopic surgery was determined according to the pathological findings. There were three transient morbidities and one permanent deficit, but no operative mortality. Transventricular endoscopic approach is an effective and reliable alternative treatment of newly diagnosed peri- and intraventricular lesions. Neuroendocopic procedures offer the opportunity to combine tumour biopsy and treatment of hydrocephalus. In selected patients, partial or total tumour removal could be performed.

  11. Image-guided transsylvian, transinsular approach for insular cavernous angiomas.

    PubMed

    Tirakotai, Wuttipong; Sure, Ulrich; Benes, Ludwig; Krischek, Boris; Bien, Sigfried; Bertalanffy, Helmut

    2003-12-01

    Surgical treatment of cavernomas arising in the insula is especially challenging because of the proximity to the internal capsule and lenticulostriate arteries. We present our technique of image guidance for operations on insular cavernomas and assess its clinical usefulness. Between 1997 and 2003, with the guidance of a frameless stereotactic system (BrainLab AG, Munich, Germany), we operated on eight patients who harbored an insular cavernoma. Neuronavigation was used for 1) accurate planning of the craniotomy, 2) identification of the distal sylvian fissure, and, finally, 3) finding the exact site for insular corticotomy. Postoperative clinical and neuroradiological evaluations were performed in each patient. The navigation system worked properly in all eight neurosurgical patients. Exact planning of the approach and determination of the ideal trajectory of dissection toward the cavernoma was possible in every patient. All cavernomas were readily identified and completely removed by use of microsurgical techniques. No surgical complications occurred, and the postoperative course was uneventful in all patients. Image guidance during surgery for insular cavernomas provides high accuracy for lesion targeting and permits excellent anatomic orientation. Accordingly, safe exposure can be obtained because of a tailored dissection of the sylvian fissure and minimal insular corticotomy.

  12. Advantages and limitations of intraoperative 3D ultrasound in neurosurgery. Technical note.

    PubMed

    Bozinov, Oliver; Burkhardt, Jan-Karl; Fischer, Claudia Miranda; Kockro, Ralf Alfons; Bernays, René-Ludwig; Bertalanffy, Helmut

    2011-01-01

    Three-dimensional ultrasound (US) technology is supposed to help combat some of the orientation difficulties inherent to two-dimensional US. Contemporary navigation solutions combine reconstructed 3D US images with common navigation images and support orientation. New real-time 3D US (without neuronavigation) is more time effective, but whether it further assists in orientation remains to be determined. An integrated US system (IGSonic, VectorVision, BrainLAB, Munich Germany) and a non-integrated system with real-time 3D US (iU22, Philips, Bothell, USA) were recently compared in neurosurgical procedures in our group. The reconstructed navigation view was time-consuming, but images were displayed in familiar planes (e.g., axial, sagittal, coronal). Further potential applications of US angiography and pure US navigation are possible. Real-time 3D images were displayed without the need for an additional acquisition and reconstruction process, but spatial orientation remained challenging in this preliminary testing phase. Reconstructed 3D US navigation appears to be superior with respect to spatial orientation, and the technique can be combined with other imaging data. However, the potential of real-time 3D US imaging is promising.

  13. 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.

  14. Preoperative or preembolization lesion targeting using rotational angiographic fiducial marking in the neuroendovascular suite.

    PubMed

    Lim, Siok Ping; Lesiuk, Howard; Sinclair, John; Lum, Cheemun

    2011-01-01

    Three-dimensional rotational digital subtraction (DS) angiography and DynaCT allow precise localization of intracranial arteriovenous fistulas (AVFs) with fiducial markers that have helped in surgical planning. These techniques are particularly useful when the AVF is not evident on cross-sectional imaging. The authors demonstrate the utility of 3D DS angiography and DynaCT in the localization of intracranial AVFs in 3 cases. Their first case was a dural AVF with multiple arterial feeders from the left occipital artery that drained into the left transverse sinus. Blood flow to the left transverse sinus was first decreased by embolizing the branch arterial feeders with polyvinyl alcohol particles. Thereafter, 3D DS angiography enabled precise localization of the site for the bur hole creation with a fiducial to allow access for the transverse sinus in the second part of the procedure where definitive transvenous sinus embolization of the dural AVF with coils was performed. They also used 3D DS angiography and DynaCT with fiducials for precise localization of a superficial pial AVF (Case 2) and a tentorial AVF (Case 3) not visible on cross-sectional angiography. With the precise localization of the target lesion, the neurosurgeons were able to perform relatively small craniotomies, minimizing the cranial opening yet allowing the opening for full access to the lesion. By correlating 3D DS angiography/DynaCT with CT images, the neurosurgeon could use neuronavigation in cases of AVF not appreciated on cross-sectional imaging.

  15. [Presurgical functional magnetic resonance imaging].

    PubMed

    Stippich, C

    2010-02-01

    Functional magnetic resonance imaging (fMRI) is an important and novel neuroimaging modality for patients with brain tumors. By non-invasive measurement, localization and lateralization of brain activiation, most importantly of motor and speech function, fMRI facilitates the selection of the most appropriate and sparing treatment and function-preserving surgery. Prerequisites for the diagnostic use of fMRI are the application of dedicated clinical imaging protocols and standardization of the respective imaging procedures. The combination with diffusion tensor imaging (DTI) also enables tracking and visualization of important fiber bundles such as the pyramidal tract and the arcuate fascicle. These multimodal MR data can be implemented in computer systems for functional neuronavigation or radiation treatment. The practicability, accuracy and reliability of presurgical fMRI have been validated by large numbers of published data. However, fMRI cannot be considered as a fully established modality of diagnostic neuroimaging due to the lack of guidelines of the responsible medical associations as well as the lack of medical certification of important hardware and software components. This article reviews the current research in the field and provides practical information relevant for presurgical fMRI.

  16. 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.

  17. Effect of repetitive transcranial magnetic stimulation on mood in healthy subjects

    PubMed Central

    Moulier, Virginie; Gaudeau-Bosma, Christian; Isaac, Clémence; Allard, Anne-Camille; Bouaziz, Noomane; Sidhoumi, Djedia; Braha-Zeitoun, Sonia; Benadhira, René; Thomas, Fanny; Januel, Dominique

    2016-01-01

    Background High frequency repetitive transcranial magnetic stimulation (rTMS) of the left dorsolateral prefrontal cortex (DLPFC) has shown significant efficiency in the treatment of resistant depression. However in healthy subjects, the effects of rTMS remain unclear. Objective Our aim was to determine the impact of 10 sessions of rTMS applied to the DLPFC on mood and emotion recognition in healthy subjects. Design In a randomised double-blind study, 20 subjects received 10 daily sessions of active (10 Hz frequency) or sham rTMS. The TMS coil was positioned on the left DLPFC through neuronavigation. Several dimensions of mood and emotion processing were assessed at baseline and after rTMS with clinical scales, visual analogue scales (VASs), and the Ekman 60 faces test. Results The 10 rTMS sessions targeting the DLPFC were well tolerated. No significant difference was found between the active group and the control group for clinical scales and the Ekman 60 faces test. Compared to the control group, the active rTMS group presented a significant improvement in their adaptation to daily life, which was assessed through VAS. Conclusion This study did not show any deleterious effect on mood and emotion recognition of 10 sessions of rTMS applied on the DLPFC in healthy subjects. This study also suggested a positive effect of rTMS on quality of life. PMID:26993786

  18. 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.

  19. 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

  20. The effects of low frequency Repetitive Transcranial Magnetic Stimulation (rTMS) and sham condition rTMS on behavioural language in chronic non-fluent aphasia: Short term outcomes.

    PubMed

    Barwood, Caroline H S; Murdoch, Bruce E; Whelan, Brooke-Mai; Lloyd, David; Riek, Stephan; O'Sullivan, John; Coulthard, Alan; Wong, Andrew; Aitken, Phil; Hall, Graham

    2011-01-01

    The application of low frequency (1 Hz) Repetitive Transcranial Magnetic Stimulation (rTMS) to right hemisphere (RH) language homologues in non-fluent aphasic populations has yielded improvements in behavioural language function, up to 43 months post stimulation. Functional imaging studies have demonstrated RH language homologue "overactivation" post left inferior frontal gyrus (IFG) damage, in chronic non-fluent aphasia. The effects of low frequency (inhibitory) rTMS are postulated to be as a result of a reduction of overactivation in RH language homologues, facilitating the reorganisation of neural language networks. Low frequency (1 Hz) rTMS was applied to the anterior portion of a Broca's area homologue (pars triangularis), for 20 minutes per day for 10 days, using a stereotactic neuronavigational system. Twelve non-fluent aphasic patients (six real stimulation and six sham), 2-10 years post stroke were stimulated. Behavioural language outcome measures were taken at baseline and 1 week post rTMS. Comparisons between the real stimulation and sham conditions indicated significant main effects between the stimulation and sham groups to 1 week post stimulation for naming accuracy, latency and repetition. This study indicates that rTMS has the capacity to modulate neural language networks, to facilitate improvements in behavioural language function, 1 week post TMS.

  1. 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.

  2. Endometriosis and Vesico-Sphincteral Disorders.

    PubMed

    Fadhlaoui, Anis; Gillon, Tessa; Lebbi, Issam; Bouquet de Jolinière, Jean; Feki, Anis

    2015-01-01

    The aim of this mini review is to determine the relationship between endometriosis and urinary tract symptoms and to investigate the consequences of surgical treatment of mild to severe endometriosis, especially deep lesions, on the vesico-sphincteral function (lower urinary tract function). We performed a literature review by searching the MEDLINE database for articles published between 2000 and 2014, limiting the searches to the words: urinary tract, vesico-sphincteral, dysfunction, endometriosis, symptoms, and surgery. The incidence of vesico-sphincteral symptoms in endometriosis varies from 3.4 up to 15.4%. The frequency of such symptoms seems to be under estimated because of a lack of specific questionnaire including urinary symptoms. Urodynamic evaluation could help to detect unsuspected abnormalities. It seems that endometriosis surgery (particularly deep infiltrating lesions) is a purveyor of de novo urinary dysfunction, with an incidence varying from 6.8 up to 17.5%. Nerve sparing processes such as neuro-navigators or neuro-stimulators seem to be promising techniques to avoid postoperative urinary tract dysfunction. A precise anamnesis and the use of specific validated questionnaires (IPSS and BFLUTS) improve the screening of vesico-sphincteral symptoms in case of endometriosis. No recommendation can be found in the literature about the place of urodynamic evaluation. Most publications lack of proof and therefore do not allow making recommendations about optimal treatment of endometriotic lesions to avoid urinary tract disorders.

  3. 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.

  4. 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.

  5. [Interdisciplinary neuro-oncology: part 2: systemic therapy of primary brain tumors].

    PubMed

    Tabatabai, G; Hattingen, E; Schlegel, J; Stummer, W; Schlegel, U

    2014-08-01

    By combining the expertise of clinical neuroscience, the aim of neuro-oncology is to optimize diagnostic planning and therapy of primary brain tumors in an interdisciplinary setting together with radio-oncology and medical oncology. High-end imaging frequently allows brain tumors to be diagnosed preoperatively with respect to tumor entity and even tumor malignancy grade. Moreover, neuroimaging is indispensable for guidance of biopsy resection and monitoring of therapy. Surgical resection of intracranial lesions with preservation of neurological function has become dramatically more extensive. Tools to achieve this goal are, for example neuronavigation, functional magnetic resonance imaging (fMRI), tractography, intraoperative cortical stimulation and precise intraoperative definition of tumor margins by virtue of various techniques. In addition to classical histopathological diagnosis and tumor classification, modern neuropathology is supplemented by molecular characterization of brain tumors in order to provide clinicians with prognostic and predictive (of therapy) markers, such as codeletion of chromosomes 1p and 19q in anaplastic gliomas and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation in glioblastomas. Although this is not yet individualized tumor therapy, the increasingly more detailed analysis of the molecular pathogenesis of an individual glioma will eventually lead to specific pharmacological blockade of disturbed intracellular pathways in individual patients. This article gives an overview of the state of the art of interdisciplinary neuro-oncology whereby part 1 deals with the diagnostics and surgical therapy of primary brain tumors and part 2 describes the medical therapy of primary brain tumors.

  6. [Interdisciplinary neuro-oncology: part 1: diagnostics and operative therapy of primary brain tumors].

    PubMed

    Tabatabai, G; Hattingen, E; Schlegel, J; Stummer, W; Schlegel, U

    2014-08-01

    By combining the expertise of clinical neuroscience, the aim of neuro-oncology is to optimize diagnostic planning and therapy of primary brain tumors in an interdisciplinary setting together with radio-oncology and medical oncology. High-end imaging frequently allows brain tumors to be diagnosed preoperatively with respect to tumor entity and even tumor malignancy grade. Moreover, neuroimaging is indispensable for guidance of biopsy resection and monitoring of therapy. Surgical resection of intracranial lesions with preservation of neurological function is increasingly feasible. Tools to achieve this goal are, for example neuronavigation, functional magnetic resonance imaging (fMRI), tractography, intraoperative cortical stimulation and precise intraoperative definition of tumor margins by virtue of various techniques. In addition to classical histopathological diagnosis and tumor classification, modern neuropathology is supplemented by molecular characterization of brain tumors in order to provide clinicians with prognostic and predictive (of therapy) markers, such as codeletion of chromosomes 1p and 19q in anaplastic gliomas and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation in glioblastomas. Although this is not yet individualized tumor therapy, the increasingly more detailed analysis of the molecular pathogenesis of an individual glioma will eventually lead to specific pharmacological blockade of disturbed intracellular pathways in individual patients. This article gives an overview of the state of the art of interdisciplinary neuro-oncology whereby part 1 deals with the diagnostics and surgical therapy of primary brain tumors and part 2 describes the medical therapy of primary brain tumors.

  7. Personal experience in transnasal endoscopic resection of the olfactory groove meningiomas. What can an otolaryngologist offer to a neurosurgeon?

    PubMed

    Skorek, Andrzej; Liczbik, Wiesław; Stankiewicz, Czesław; Kloc, Wojciech; Plichta, Łukasz

    2014-05-01

    Olfactory groove meningioma is a demanding therapeutic problem involving two medical specialties, otolaryngology and neurosurgery. The use of transnasal endoscopic (TNE) approach to the tumour has been proved effective in many publications. Three patients with meningiomas localized in olfactory groove were treated in 2011 and 2012 by the otolaryngologist-neurosurgeon team using TNE approach and neuronavigation. The diagnosis was based on MR and CT images. In all patients after tumour removal an endoscopic anterior cranial fossa floor reconstruction was performed using homogeneous cartilage or titanium mesh and Hadad-Bassagasteguy flap. During postoperative period in all patients lumbar drainage was used. There were no cerebrospinal fluid leakage episodes. No recurrence was observed in 22, 12 and 8 months of follow-up, respectively. The authors describe otolaryngological and neurosurgical aspects of TNE approach to anterior cranial fossa with special regard to possible radical resection (according to Simpson) and reconstruction of the bony postoperative defect. TNE is a feasible operative method in olfactory groove meningioma management due to good tumour visibility, lack of brain traction, limited neurovascular structure manipulation and acceptable risk of neurological deficiencies when compared to open approach. Cosmetic aspect and short hospitalization is also of great importance.

  8. 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.

  9. Supra-complete surgery via dual intraoperative visualization approach (DiVA) prolongs patient survival in glioblastoma.

    PubMed

    Eyüpoglu, Ilker Y; Hore, Nirjhar; Merkel, Andreas; Buslei, Rolf; Buchfelder, Michael; Savaskan, Nicolai

    2016-05-03

    Safe and complete resection represents the first step in the treatment of glioblastomas and is mandatory in increasing the effectiveness of adjuvant therapy to prolong overall survival. With gross total resection currently limited in extent to MRI contrast enhancing areas, the extent to which supra-complete resection beyond obvious contrast enhancement could have impact on overall survival remains unclear. DiVA (dual intraoperative visualization approach) redefines gross total resection as currently accepted by enabling for the first time supra-complete surgery without compromising patient safety. This approach exploits the advantages of two already accepted surgical techniques combining intraoperative MRI with integrated functional neuronavigation and 5-ALA by integrating them into a single surgical approach. We investigated whether this technique has impact on overall outcome in GBM patients. 105 patients with GBM were included. We achieved complete resection with intraoperative MRI alone according to current best-practice in glioma surgery in 75 patients. 30 patients received surgery with supra-complete resection. The control arm showed a median life expectancy of 14 months, reflecting current standards-of-care and outcome. In contrast, patients receiving supra-complete surgery displayed significant increase in median survival time to 18.5 months with overall survival time correlating directly with extent of supra-complete resection. This extension of overall survival did not come at the cost of neurological deterioration. We show for the first time that supra-complete glioma surgery leads to significant prolongation of overall survival time in GBM patients.

  10. Corticospinal Excitability Modulation During Action Observation

    PubMed Central

    Sartori, Luisa; Betti, Sonia; Castiello, Umberto

    2013-01-01

    This study used the transcranial magnetic stimulation/motor evoked potential (TMS/MEP) technique to pinpoint when the automatic tendency to mirror someone else's action becomes anticipatory simulation of a complementary act. TMS was delivered to the left primary motor cortex corresponding to the hand to induce the highest level of MEP activity from the abductor digiti minimi (ADM; the muscle serving little finger abduction) as well as the first dorsal interosseus (FDI; the muscle serving index finger flexion/extension) muscles. A neuronavigation system was used to maintain the position of the TMS coil, and electromyographic (EMG) activity was recorded from the right ADM and FDI muscles. Producing original data with regard to motor resonance, the combined TMS/MEP technique has taken research on the perception-action coupling mechanism a step further. Specifically, it has answered the questions of how and when observing another person's actions produces motor facilitation in an onlooker's corresponding muscles and in what way corticospinal excitability is modulated in social contexts. PMID:24429584

  11. A systematic pipeline for the objective comparison of whole-brain spectroscopic MRI with histology in biopsy specimens from grade III glioma

    PubMed Central

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

    2016-01-01

    The diagnosis, prognosis, and management of patients with gliomas are largely dictated by the pathological analysis of tissue biopsied from a selected region within the lesion. However, due to the heterogeneous and infiltrative nature of gliomas, identifying the optimal region for biopsy with conventional magnetic resonance imaging (MRI) can be quite difficult. This is especially true for low grade gliomas, which often are non-enhancing tumors. To improve the management of patients with these tumors, the field of neuro-oncology requires an imaging modality that can specifically identify a tumor’s most anaplastic/aggressive region(s) for biopsy targeting. The addition of metabolic mapping using spectroscopic MRI (sMRI) to supplement conventional MRI could improve biopsy targeting and, ultimately, diagnostic accuracy. Here, we describe a pipeline for the integration of state-of-the-art, high-resolution whole-brain 3D sMRI maps into a stereotactic neuronavigation system for guiding biopsies in gliomas with nonenhancing components. We also outline a machine-learning method for automated histology analysis that generates normalized, quantitative metrics describing tumor infiltration in immunohistochemically-stained tissue specimens. As a proof of concept, we describe the combination of these two techniques in a small cohort of grade III glioma patients. In this work, we aim to set forth a systematic pipeline to stimulate histopathology-image validation of advanced MRI techniques, such as sMRI. PMID:27489883

  12. Disrupting pre-SMA activity impairs facial happiness recognition: an event-related TMS study.

    PubMed

    Rochas, Vincent; Gelmini, Lauriane; Krolak-Salmon, Pierre; Poulet, Emmanuel; Saoud, Mohamed; Brunelin, Jerome; Bediou, Benoit

    2013-07-01

    It has been suggested that the left pre-supplementary motor area (pre-SMA) could be implicated in facial emotion expression and recognition, especially for laughter/happiness. To test this hypothesis, in a single-blind, randomized crossover study, we investigated the impact of transcranial magnetic stimulation (TMS) on performances of 18 healthy participants during a facial emotion recognition task. Using a neuronavigation system based on T1-weighted magnetic resonance imaging of each participant, TMS (5 pulses, 10 Hz) was delivered over the pre-SMA or the vertex (control condition) in an event-related fashion after the presentation of happy, fear, and angry faces. Compared with performances during vertex stimulation, we observed that TMS applied over the left pre-SMA specifically disrupted facial happiness recognition (FHR). No difference was observed between the 2 conditions neither for fear and anger recognition nor for reaction times (RT). Thus, interfering with pre-SMA activity with event-related TMS after stimulus presentation produced a selective impairment in the recognition of happy faces. These findings provide new insights into the functional implication of the pre-SMA in FHR, which may rely on the mirror properties of pre-SMA neurons.

  13. 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.

  14. Mutual-information-corrected tumor displacement using intraoperative ultrasound for brain shift compensation in image-guided neurosurgery

    NASA Astrophysics Data System (ADS)

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

    2008-03-01

    Intraoperative ultrasound (iUS) has emerged as a practical neuronavigational tool for brain shift compensation in image-guided tumor resection surgeries. The use of iUS is optimized when coregistered with preoperative magnetic resonance images (pMR) of the patient's head. However, the fiducial-based registration alone does not necessarily optimize the alignment of internal anatomical structures deep in the brain (e.g., tumor) between iUS and pMR. In this paper, we investigated and evaluated an image-based re-registration scheme to maximize the normalized mutual information (nMI) between iUS and pMR to improve tumor boundary alignment using the fiducial registration as a starting point for optimization. We show that this scheme significantly (p<<0.001) reduces tumor boundary misalignment pre-durotomy. The same technique was employed to measure tumor displacement post-durotomy, and the locally measured tumor displacement was assimilated into a biomechanical model to estimate whole-brain deformation. Our results demonstrate that the nMI re-registration pre-durotomy is critical for obtaining accurate measurement of tumor displacement, which significantly improved model response at the craniotomy when compared with stereopsis data acquired independently from the tumor registration. This automatic and computationally efficient (<2min) re-registration technique is feasible for routine clinical use in the operating room (OR).

  15. Glioblastoma: changing expectations?

    PubMed

    Arribas Alpuente, Leoncio; Menéndez López, Antonio; Yayá Tur, Ricardo

    2011-04-01

    Glioblastoma (GB) represents the most aggressive glioma in the adult population. Despite recent research efforts, the prognosis of patients with GB has remained dismal. Lately, the knowledge of genetic information about gliomagenesis has increased; we even have a classification of the genetic expression of the tumour. The main problem is that at the moment we do not have any therapeutical resources to help us better treat these tumours, as we can do, with others tumours like breast, lung and colorectal cancer. We have also improved on diagnostic imaging, especially with the new MRI sequences; we can now better define the characteristics of the tumour area and the surrounding brain structures, allowing us to adjust resections. Thanks to the most advanced surgery techniques, such as neuronavigation, intraoperative control of the nervous function and the tumour volume, the neurosurgeon is able to complete tumour exeresis with less morbidity. These imaging techniques allow the radiation oncologist to better contour the irradiation target volume, the structures and the organs at risk, to diminish the irradiation of apparently healthy tissue. Nowadays, knowledge of brain stem cells provides new expectations for future treatments. Novel targeted agents such as bevacizumab, imatinib, erlotinib, temsirolimus, immunotherapy, cilengitide, talampanel, etc. are helping classical chemotherapeutic agents, like temozolomide, to achieve an increase in overall survival. The main objective is to improve median overall survival, which is currently between 9 and 12 months, with a good quality of life, measured by the ability to carry out daily life activities.

  16. Endoscopic endonasal odontoid resection with real-time intraoperative image-guided computed tomography: report of 4 cases.

    PubMed

    Singh, Harminder; Rote, Sarang; Jada, Ajit; Bander, Evan D; Almodovar-Mercado, Gustavo J; Essayed, Walid I; Härtl, Roger; Anand, Vijay K; Schwartz, Theodore H; Greenfield, Jeffrey P

    2017-06-16

    The authors present 4 cases in which they used intraoperative CT (iCT) scanning to provide real-time image guidance during endonasal odontoid resection. While intraoperative CT has previously been used as a confirmatory test after resection, to the authors' knowledge this is the first time it has been used to provide real-time image guidance during endonasal odontoid resection. The operating room setup, as well as the advantages and pitfalls of this approach, are discussed. A mobile intraoperative CT scanner was used in conjunction with real-time craniospinal neuronavigation in 4 patients who underwent endoscopic endonasal odontoidectomy for basilar invagination. All patients underwent a successful decompression. In 3 of the 4 patients, real-time intraoperative CT image guidance was instrumental in achieving a comprehensive decompression. In 3 (75%) cases in which the right nostril was the predominant working channel, there was a tendency for asymmetrical decompression toward the right side, meaning that residual bone was seen on the left, which was subsequently removed prior to completion of the surgery. Endoscopic endonasal odontoid resection with real-time intraoperative image-guided CT scanning is feasible and provides accurate intraoperative localization of pathology, thereby increasing the chance of a complete odontoidectomy. For right-handed surgeons operating predominantly through the right nostril, special attention should be paid to the contralateral side of the resection, where there is often a tendency for residual pathology.

  17. A systematic evaluation of intraoperative white matter tract shift in pediatric epilepsy surgery using high-field MRI and probabilistic high angular resolution diffusion imaging tractography.

    PubMed

    Yang, Joseph Yuan-Mou; Beare, Richard; Seal, Marc L; Harvey, A Simon; Anderson, Vicki A; Maixner, Wirginia J

    2017-05-01

    OBJECTIVE Characterization of intraoperative white matter tract (WMT) shift has the potential to compensate for neuronavigation inaccuracies using preoperative brain imaging. This study aimed to quantify and characterize intraoperative WMT shift from the global hemispheric to the regional tract-based scale and to investigate the impact of intraoperative factors (IOFs). METHODS High angular resolution diffusion imaging (HARDI) diffusion-weighted data were acquired over 5 consecutive perioperative time points (MR1 to MR5) in 16 epilepsy patients (8 male; mean age 9.8 years, range 3.8-15.8 years) using diagnostic and intraoperative 3-T MRI scanners. MR1 was the preoperative planning scan. MR2 was the first intraoperative scan acquired with the patient's head fixed in the surgical position. MR3 was the second intraoperative scan acquired following craniotomy and durotomy, prior to lesion resection. MR4 was the last intraoperative scan acquired following lesion resection, prior to wound closure. MR5 was a postoperative scan acquired at the 3-month follow-up visit. Ten association WMT/WMT segments and 1 projection WMT were generated via a probabilistic tractography algorithm from each MRI scan. Image registration was performed through pairwise MRI alignments using the skull segmentation. The MR1 and MR2 pairing represented the first surgical stage. The MR2 and MR3 pairing represented the second surgical stage. The MR3 and MR4 (or MR5) pairing represented the third surgical stage. The WMT shift was quantified by measuring displacements between a pair of WMT centerlines. Linear mixed-effects regression analyses were carried out for 6 IOFs: head rotation, craniotomy size, durotomy size, resected lesion volume, presence of brain edema, and CSF loss via ventricular penetration. RESULTS The average WMT shift in the operative hemisphere was 2.37 mm (range 1.92-3.03 mm) during the first surgical stage, 2.19 mm (range 1.90-3.65 mm) during the second surgical stage, and 2.92 mm

  18. Mass Spectrometry Imaging as a Tool for Surgical Decision-Making

    PubMed Central

    Calligaris, David; Norton, Isaiah; Feldman, Daniel R.; Ide, Jennifer L.; Dunn, Ian F.; Eberlin, Livia S.; Cooks, R. Graham; Jolesz, Ferenc A.; Golby, Alexandra J.; Santagata, Sandro; Agar, Nathalie Y.

    2014-01-01

    Despite significant advances in image-guided therapy, surgeons are still too often left with uncertainty when deciding to remove tissue. This binary decision between removing and leaving tissue during surgery implies that the surgeon should be able to distinguish tumor from healthy tissue. In neurosurgery, current image-guidance approaches such as magnetic resonance imaging (MRI) combined with neuro-navigation offer a map as to where the tumor should be, but the only definitive method to characterize the tissue at stake is histopathology. While extremely valuable information is derived from this gold standard approach, it is limited to very few samples during surgery and is not practically used for the delineation of tumor margins. The development and implementation of faster, comprehensive and complementary approaches for tissue characterization are required to support surgical decision-making – an incremental and iterative process with tumor removed in multiple and often minute biopsies. The development of atmospheric pressure ionization sources makes it possible to analyze tissue specimens with little to no sample preparation. Here, we highlight the value of desorption electrospray ionization (DESI) as one of many available approaches for the analysis of surgical tissue. Twelve surgical samples resected from a patient during surgery were analyzed and diagnosed as glioblastoma (GBM) tumor or necrotic tissue by standard histopathology, and mass spectrometry results were further correlated to histopathology for critical validation of the approach. The use of a robust statistical approach reiterated results from the qualitative detection of potential biomarkers of these tissue types. The correlation of the MS and histopathology results to magnetic resonance images brings significant insight into tumor presentation that could not only serve to guide tumor resection, but that is worthy of more detailed studies on our understanding of tumor presentation on MRI. PMID

  19. 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.

  20. 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

  1. 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.

  2. A minimally invasive anterior skull base approach for evacuation of a basal ganglia hemorrhage.

    PubMed

    Ding, Dale; Przybylowski, Colin J; Starke, Robert M; Sterling Street, R; Tyree, Amber E; Webster Crowley, R; Liu, Kenneth C

    2015-11-01

    We describe the technical nuances of a minimally invasive anterior skull base approach for microsurgical evacuation of a large basal ganglia hematoma through an endoport. Patients who suffer from large spontaneous intracerebral hemorrhages (ICH) of the basal ganglia have a very poor prognosis. However, the benefit of surgery for the management of ICH is controversial. The development of endoport technology has allowed for minimally invasive access to subcortical lesions, and may offer unique advantages over conventional surgical techniques due to less disruption of the overlying cortex and white matter fiber tracts. A 77-year-old man presented with a hypertensive ICH of the right putamen, measuring 9 cm in maximal diameter and 168 cm(3) in volume. We planned an endoport trajectory through the long axis of the hematoma using frameless stereotactic neuronavigation. In order to access the optimal cortical entry point at the lateral aspect of the basal frontal lobe, a miniature modified orbitozygomatic skull base craniotomy was performed through an incision along the superior border of the right eyebrow. Using the BrainPath endoport system (NICO, Indianapolis, IN, USA), the putaminal hematoma was successfully evacuated, resulting in an 87% postoperative reduction in ICH volume. Thus, we show that, in appropriately selected cases, endoport-assisted microsurgery is safe and effective for the evacuation of large ICH. Furthermore, minimally invasive anterior skull base approaches can be employed to expand the therapeutic potential of endoport-assisted approaches to include subcortical lesions, such as hematomas of the basal ganglia. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Navigated high frequency ultrasound: description of technique and clinical comparison with conventional intracranial ultrasound.

    PubMed

    Coburger, Jan; König, Ralph W; Scheuerle, Angelika; Engelke, Jens; Hlavac, Michal; Thal, Dietmar R; Wirtz, Christian Rainer

    2014-01-01

    Conventional curved or sector array ultrasound (cioUS) is the most commonly used intraoperative imaging modality worldwide. Although highly beneficial in various clinical applications, at present the impact of linear array intraoperative ultrasound (lioUS) has not been assessed for intracranial use. We provide a technical description to integrate an independent lioUS probe into a commercially available neuronavigation system and evaluate the use of navigated lioUS as a resection control in glioblastoma surgery. We performed a prospective study assessing residual tumor detection after complete microsurgical resection using either cioUS or lioUS in 15 consecutive patients. We compared the imaging findings of both ultrasound modalities in 44 sites surrounding the resection cavity. The respective findings were correlated with the histopathologic findings of tissue specimen obtained from those sites. Use of cioUS leaded to an additional resection in 9 patients, whereas lioUS detected residual tumor during all surgeries. A further resection was performed at 33 of 44 intraoperative sites (75%) based on results of lioUS alone. Resected tissue was solid tumor in 66% and infiltration zone in 34%. No false-positive or false-negative findings were seen using lioUS. There was no case of a tumor detection in cioUS combined with a negative finding in lioUS. The difference of imaging results between cioUS and lioUS was significant (sign test, P<0.001). lioUS can be used as a safe and precise tool for intracranial image-guided resection control of glioblastomas. It can be integrated in a commercially available navigation system and shows a significant higher detection rate of residual tumor compared with conventional cioUS. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Presurgical functional MR imaging of language and motor functions: validation with intraoperative electrocortical mapping.

    PubMed

    Bizzi, Alberto; Blasi, Valeria; Falini, Andrea; Ferroli, Paolo; Cadioli, Marcello; Danesi, Ugo; Aquino, Domenico; Marras, Carlo; Caldiroli, Dario; Broggi, Giovanni

    2008-08-01

    To prospectively determine the sensitivity and specificity of functional magnetic resonance (MR) imaging for mapping language and motor functions in patients with a focal mass adjacent to eloquent cortex, by using intraoperative electrocortical mapping (ECM) as the reference standard. The ethics committee approved the study, and patients gave written informed consent. Thirty-four consecutive patients (16 women, 18 men; mean age, 43.2 years) were included who met the following three criteria: They had a focal mass in or adjacent to eloquent cortex of the language or motor system, they had the ability to perform the functional MR imaging task, and they had to undergo surgery with intraoperative ECM. Functional MR imaging with verb generation (n = 17) or finger tapping of the contralateral hand (n = 17) was performed at 1.5 T with a block design and an echo-planar gradient-echo T2*-weighted sequence. Cortex essential for language or hand motor functions was mapped with ECM. A site-by-site comparison between functional MR imaging and ECM was performed with the aid of a neuronavigational device. Sensitivity and specificity were calculated according to task performed, histopathologic findings, and tumor grade. Exact 95% confidence intervals were calculated for each sensitivity and specificity value. For 34 consecutive patients, there were 28 with gliomas, two with metastases, one with meningioma, and three with cavernous angiomas. A total of 251 cortical sites were tested with ECM; overall functional MR imaging sensitivity and specificity were 83% and 82%, respectively. Sensitivity (65%) was lower and specificity (93%) was higher in World Health Organization grade IV gliomas compared with grade II (sensitivity, 93%; specificity, 79%) and III (sensitivity, 93%; specificity, 76%) gliomas. At 3 months after surgery, language proficiency was unchanged in 15 patients; functionality of the contralateral arm was unchanged in 14 patients and improved in one patient. Functional

  5. Frameless stereotactic neurosurgery: two steps towards the Holy Grail of surgical navigation.

    PubMed

    Eljamel, M S

    1999-01-01

    The holy grail of surgical navigation is to provide precise continuous feedback during surgery about the target and its surrounding structures. The first step was the ability of hardware and software technology to allow patient-to-image registration using a multi-potentiometer position-sensing articulated arm system. We used such a system (OAS; Radionics, Burlington, Mass., USA) in 169 consecutive patients with common intracranial lesions. We achieved a mean application accuracy of 2.5 mm, which was sufficiently reliable for most neurosurgical procedures. However, to get the feedback information, the surgeon has to look away from the operative field to the workstation monitor. As psychological studies of manual workers including surgeons indicated that performance is better when the worker is looking in a downward gaze at his hands, the natural progression was to project feedback information between the eyes and the hands. Therefore, the second step was to link tracking technology to the surgical microscope with head-up display. We used such a system (SMN-Zeiss, Germany) in 65 consecutive patients with a mean application accuracy of 1.4 mm. This was again sufficiently reliable for neuronavigation. The head-up display provided continuous feedback to the surgeon about the target, risk zones and areas of interest without the need to interrupt the procedure to get such information. Furthermore, the use of the focal length of SMN with autofocus to perform the registration improved the application accuracy of this technology. The ability of the software to process all MRI sequences (T(1), T(2), MPR and CISS) allowed us to use a variety of image sequences to delineate the lesion more exquisitely. Copyright 2000 S. Karger AG, Basel

  6. Testing a Neurobiological Model of Depersonalization Disorder Using Repetitive Transcranial Magnetic Stimulation☆

    PubMed Central

    Jay, Emma-Louise; Sierra, Mauricio; Van den Eynde, Frederique; Rothwell, John C.; David, Anthony S.

    2014-01-01

    Background Depersonalization disorder (DPD) includes changes in subjective experiencing of self, encompassing emotional numbing. Functional magnetic resonance imaging (fMRI) has pointed to ventrolateral prefrontal cortex (VLPFC) inhibition of insula as a neurocognitive correlate of the disorder. Objective We hypothesized that inhibition to right VLPFC using repetitive transcranial magnetic stimulation (rTMS) would lead to increased arousal and reduced symptoms. Methods Patients with medication-resistant DSM-IV DPD (N = 17) and controls (N = 20) were randomized to receive one session of right-sided rTMS to VLPFC or temporo-parietal junction (TPJ). 1Hz rTMS was guided using neuronavigation and delivered for 15 min. Co-primary outcomes were: (a) maximum skin conductance capacity, and (b) reduction in depersonalization symptoms (Cambridge Depersonalisation Scale (CDS) [state version]). Secondary outcomes included spontaneous fluctuations (SFs) and event-related skin conductance responses. Results In patients with DPD, rTMS to VLPFC led to increased electrodermal capacity, namely maximum skin conductance deflections. Patients but not controls also showed increased SFs post rTMS. Patients who had either VLPFC or TPJ rTMS showed a similar significant reduction in symptoms. Event-related electrodermal activity did not change. Conclusions A single session of right-sided rTMS to VLPFC (but not TPJ) significantly increased physiological arousal capacity supporting our model regarding the relevance of increased VLPFC activity to emotional numbing in DPD. rTMS to both sites led to reduced depersonalization scores but since this was independent of physiological arousal, this may be a non-specific effect. TMS is a potential therapeutic option for DPD; modulation of VLPFC, if replicated, is a plausible mechanism. PMID:24439959

  7. The supraorbital keyhole approach via an eyebrow incision applied to obtain the olfactory bulb as a source of olfactory ensheathing cells--radiological feasibility study.

    PubMed

    Czyż, Marcin; Tabakow, Paweł; Gheek, Daniel; Miś, Marcin; Jarmundowicz, Włodzimierz; Raisman, Geoffrey

    2014-04-01

    BACKGROUND. The purpose of the study was to test the suitability of supraorbital keyhole craniotomy with an eyebrow incision for obtaining olfactory bulb for therapeutic purposes. METHODS. Fifty three high-resolution axial head computed tomography images of patients with a mean age of 55 ± 15 years were used. The exclusion criterion was a pathology of the anterior skull base. The virtual keyhole supraorbital craniotomy was placed on each side of a three-dimensional skull model with respect to the anatomical landmarks. Trajectories of neurosurgical instrument transitions to the anterior and posterior aspects of olfactory grooves (OGs) were subsequently designed with the use of a neuronavigation planning station and measured with correction allowing the avoidance of collisions with skull base structures. Three types of anatomical configuration were divided, reflecting the extent of the correction needed to reach the bottom of OG. RESULTS. Simulation of the surgical access and consequent metrological analysis was performed on 97 skull sides - 9 (8.5%) sides were excluded due to the large frontal sinus. The mean length of the craniotomy basis was 30.71 mm, lengths of the anterior and posterior trajectories were 53.25 and 58.24 mm, respectively (p < 0.0001). In 37% of cases the value of the corrections exceeded the depth of OG. CONCLUSIONS. The supraorbital keyhole approach via an eyebrow incision may be applied to obtain the olfactory bulb as a source of olfactory ensheathing cells in over 60% of cases. Further verification and evaluation of the surgical handiness based on cadaver specimens is justifiable.

  8. An Experimental Protocol for Assessing the Performance of New Ultrasound Probes Based on CMUT Technology in Application to Brain Imaging.

    PubMed

    Matrone, Giulia; Ramalli, Alessandro; Savoia, Alessandro Stuart; Quaglia, Fabio; Castellazzi, Gloria; Morbini, Patrizia; Piastra, Marco

    2017-09-24

    The possibility to perform an early and repeatable assessment of imaging performance is fundamental in the design and development process of new ultrasound (US) probes. Particularly, a more realistic analysis with application-specific imaging targets can be extremely valuable to assess the expected performance of US probes in their potential clinical field of application. The experimental protocol presented in this work was purposely designed to provide an application-specific assessment procedure for newly-developed US probe prototypes based on Capacitive Micromachined Ultrasonic Transducer (CMUT) technology in relation to brain imaging. The protocol combines the use of a bovine brain fixed in formalin as the imaging target, which ensures both realism and repeatability of the described procedures, and of neuronavigation techniques borrowed from neurosurgery. The US probe is in fact connected to a motion tracking system which acquires position data and enables the superposition of US images to reference Magnetic Resonance (MR) images of the brain. This provides a means for human experts to perform a visual qualitative assessment of the US probe imaging performance and to compare acquisitions made with different probes. Moreover, the protocol relies on the use of a complete and open research and development system for US image acquisition, i.e. the Ultrasound Advanced Open Platform (ULA-OP) scanner. The manuscript describes in detail the instruments and procedures involved in the protocol, in particular for the calibration, image acquisition and registration of US and MR images. The obtained results prove the effectiveness of the overall protocol presented, which is entirely open (within the limits of the instrumentation involved), repeatable, and covers the entire set of acquisition and processing activities for US images.

  9. Evaluation of preoperative high magnetic field motor functional MRI (3 Tesla) in glioma patients by navigated electrocortical stimulation and postoperative outcome.

    PubMed

    Roessler, K; Donat, M; Lanzenberger, R; Novak, K; Geissler, A; Gartus, A; Tahamtan, A R; Milakara, D; Czech, T; Barth, M; Knosp, E; Beisteiner, R

    2005-08-01

    The validity of 3 Tesla motor functional magnetic resonance imaging (fMRI) in patients with gliomas involving the primary motor cortex was investigated by intraoperative navigated motor cortex stimulation (MCS). Twenty two patients (10 males, 12 females, mean age 39 years, range 10-65 years) underwent preoperative fMRI studies, performing motor tasks including hand, foot, and mouth movements. A recently developed high field clinical fMRI technique was used to generate pre-surgical maps of functional high risk areas defining a motor focus. Motor foci were tested for validity by intraoperative motor cortex stimulation (MCS) employing image fusion and neuronavigation. Clinical outcome was assessed using the Modified Rankin Scale. FMRI motor foci were successfully detected in all patients preoperatively. In 17 of 22 patients (77.3%), a successful stimulation of the primary motor cortex was possible. All 17 correlated patients showed 100% agreement on MCS and fMRI motor focus within 10 mm. Technical problems during stimulation occurred in three patients (13.6%), no motor response was elicited in two (9.1%), and MCS induced seizures occurred in three (13.6%). Combined fMRI and MCS mapping results allowed large resections in 20 patients (91%) (gross total in nine (41%), subtotal in 11 (50%)) and biopsy in two patients (9%). Pathology revealed seven low grade and 15 high grade gliomas. Mild to moderate transient neurological deterioration occurred in six patients, and a severe hemiparesis in one. All patients recovered within 3 months (31.8% transient, 0% permanent morbidity). The validation of clinically optimised high magnetic field motor fMRI confirms high reliability as a preoperative and intraoperative adjunct in glioma patients selected for surgery within or adjacent to the motor cortex.

  10. Application of technical strategies for surgical management of adult intrinsic pontine gliomas: a retrospective series.

    PubMed

    Yang, Xiang; Ren, Yan-Ming; Hui, Xu-Hui; Liu, Xue-Song; Wu, Wen-Tao; Zhang, Yue-Kang

    2015-01-01

    The authors retrospectively analyzed the surgical treatment of adult intrinsic pontine gliomas in their department, and to enhance the understanding of technical strategies to treat this disease. 7 patients with intrinsic pontine gliomas were recruited for this study, between January 2011 and June 2013. All patients underwent preoperative MRI and Diffusion Tensor Imaging Fiber Tracking (DTI-FT). In addition, multimodal Intraoperative Neuromonitoring (IOM) and Intraoperative Neuronavigation were also applied during microsurgery. 7 patients with intrinsic pontine gliomas were treated at the West China Hospital of Sichuan University. Mean age, mean duration of symptoms prior to diagnosis, and mean duration of follow-up average time were 38.0 years, 2.0 months, and 23.4 months, respectively. The main presentations were progressive cranial nerve deficits and long tract signs. Total resection was achieved in 3 patients, subtotal resection in 2, and partial resection in 2. Postoperative pathological examination revealed: astrocytoma (WHO II) in 4 cases, anaplastic oligoastrocytoma (AO, WHO III) in one case, and anaplastic astrocytoma (AA, WHO III) in two cases. Postoperative radiotherapy were administered to all patients, and 4 patients with astrocytoma (WHO II) rejected chemotherapy. After 11-39 months of follow-up, patient symptoms were resolved or stable without aggravation except one patient died because of rapidly progressive glioma at 11 months after operation. MRI in other patients showed residual tumor size to be unchanged or without obviously recurrence. Combining preoperative MRI with preoperative DTI-FT, surgery can be better assessed and the operation for adult intrinsic pontine gliomas can be maximally and safely resected with the aid of Multimodal IOMs and Intraoperative Navigation during microsurgery.

  11. 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.

  12. Comparison of navigated transcranial magnetic stimulation and functional magnetic resonance imaging for preoperative mapping in rolandic tumor surgery.

    PubMed

    Coburger, Jan; Musahl, Christian; Henkes, Hans; Horvath-Rizea, Diana; Bittl, Markus; Weissbach, Claudia; Hopf, Nikolai

    2013-01-01

    Navigated transcranial magnetic stimulation (nTMS) is a novel tool for preoperative functional mapping. It detects eloquent cortical areas directly, comparable to intraoperative direct cortical stimulation (DCS). The aim of this study was to evaluate the advantage of nTMS in comparison with functional magnetic resonance imaging (fMRI) in the clinical setting. Special focus was placed on accuracy of motor cortex localization in patients with rolandic lesions. Thirty consecutive patients were enrolled in the study. All patients received an fMRI and nTMS examination preoperatively. Feasibility of the technique and spatial resolution of upper and lower extremity cortical mapping were compared with fMRI. Consistency of preoperative mapping with intraoperative DCS was assessed via the neuronavigation system. nTMS was feasible in all 30 patients. fMRI was impossible in 7 out of 30 patients with special clinical conditions, pediatric patients, central vascular lesions, or compliance issues. The mean accuracy to localize motor cortex of nTMS was higher than in fMRI. In the subgroup of intrinsic tumors, nTMS produced statistically significant higher accuracy scores of the lower extremity localization than fMRI. fMRI failed to localize hand or leg areas in 6 out of 23 cases. Using nTMS, a preoperative localization of the central sulcus was possible in all patients. Verification of nTMS motor cortex localization with DCS was achieved in all cases. The fMRI localization of the hand area proved to be postcentral in one case. nTMS has fewer restrictions for preoperative functional mapping than fMRI and requires only a limited level of compliance. nTMS scores higher on the accuracy scale than fMRI. nTMS represents a highly valuable supplement for the preoperative functional planning in the clinical routine.

  13. Modulation of N400 in chronic non-fluent aphasia using low frequency Repetitive Transcranial Magnetic Stimulation (rTMS).

    PubMed

    Barwood, Caroline H S; Murdoch, Bruce E; Whelan, Brooke-Mai; Lloyd, David; Riek, Stephan; O'Sullivan, John D; Coulthard, Alan; Wong, Andrew

    2011-03-01

    Low frequency Repetitive Transcranial Magnetic Stimulation (rTMS) has previously been applied to language homologues in non-fluent populations of persons with aphasia yielding significant improvements in behavioral language function up to 43 months post stimulation. The present study aimed to investigate the electrophysiological correlates associated with the application of rTMS through measurement of the semantic based N400 Event-related brain potentials (ERP) component. Low frequency (1 Hz) rTMS was applied to the anterior portion of the homologue to Broca's area (pars triangularis), for 20 min per day for 10 days, using a stereotactic neuronavigational system. Twelve non-fluent persons with aphasia, 2-6 years post stroke were stimulated. Six participants were randomly assigned to receive real stimulation and six participants were randomly assigned to receive a blind sham control condition. ERP measures were recorded at baseline, 1 week and 2 months subsequent to stimulation. The findings demonstrate treatment related changes observed in the stimulation group when compared to the placebo control group at 2 months post stimulation indicating neuromodulation of N400 as a result of rTMS. No treatment related changes were identified in the stimulation group, when compared to the sham group from baseline to 1 week post stimulation. The electrophysiological results represent the capacity of rTMS to modulate neural language networks and measures of lexical-semantic function in participants with non-fluent aphasia and suggest that time may be an important factor in brain reorganization subsequent to rTMS.

  14. An experimental study on the mechanical properties of rat brain tissue using different stress-strain definitions.

    PubMed

    Karimi, Alireza; Navidbakhsh, Mahdi

    2014-07-01

    There are different stress-strain definitions to measure the mechanical properties of the brain tissue. However, there is no agreement as to which stress-strain definition should be employed to measure the mechanical properties of the brain tissue at both the longitudinal and circumferential directions. It is worth knowing that an optimize stress-strain definition of the brain tissue at different loading directions may have implications for neuronavigation and surgery simulation through haptic devices. This study is aimed to conduct a comparative study on different results are given by the various definitions of stress-strain and to recommend a specific definition when testing brain tissues. Prepared cylindrical samples are excised from the parietal lobes of rats' brains and experimentally tested by applying load on both the longitudinal and circumferential directions. Three stress definitions (second Piola-Kichhoff stress, engineering stress, and true stress) and four strain definitions (Almansi-Hamel strain, Green-St. Venant strain, engineering strain, and true strain) are used to determine the elastic modulus, maximum stress and strain. The highest non-linear stress-strain relation is observed for the Almansi-Hamel strain definition and it may overestimate the elastic modulus at different stress definitions at both the longitudinal and circumferential directions. The Green-St. Venant strain definition fails to address the non-linear stress-strain relation using different definitions of stress and triggers an underestimation of the elastic modulus. The results suggest the application of the true stress-true strain definition for characterization of the brain tissues mechanics since it gives more accurate measurements of the tissue's response using the instantaneous values.

  15. The contralateral transfalcine transprecuneus approach to the atrium of the lateral ventricle: operative technique and surgical results.

    PubMed

    Xie, Tao; Sun, Chongjing; Zhang, Xiaobiao; Zhu, Wei; Zhang, Jianping; Gu, Ye; Li, Wensheng

    2015-03-01

    Surgical approaches to the atrium of the lateral ventricle remain a challenging neurosurgical issue because of the eloquent nature of the surrounding anatomy. To report our operative techniques and preliminary surgical results with the contralateral transfalcine transprecuneus approach. A retrospective data review was performed of patients undergoing a contralateral transfalcine transprecuneus approach for the resection of lesions in the atrium of the lateral ventricle. Patients were positioned in the prone position with a 30° elevation, and a 15° rotation was used. After a contralateral parasagittal parieto-occipital craniotomy and falx incision, the corticotomy in the contralateral precuneus gyrus created a corridor to the tumor. An endoscope was used to assist with the surgery. Headache was the primary preoperative symptom, which improved in all patients after surgery. After treatment, symptoms were improved in all 3 patients with hemiparesis and in 3 of 6 patients with preexisting visual deficits; symptoms were unchanged in the other 3 patients with visual deficits during the 13- to 38-month follow-up. Nine lesions were totally removed, and 1 metastatic breast cancer lesion was subtotally removed; all patients had good neurological outcomes and no operative mortality. The contralateral transfalcine transprecuneus approach is appropriate for most lesions in the atrium of the lateral ventricle. It provides a wider surgical angle (especially for the lateral extension) and reduces the risk of disturbance of the optic radiation compared with the conventional approaches. The use of magnetic resonance venography-magnetic resonance imaging neuronavigation makes the procedure much easier and more accurate, and the neuroendoscope adds to the visualization of the microscope and can reduce surgical complications.

  16. Qualitative and Quantitative Radio-Anatomical Variation of the Posterior Clinoid Process

    PubMed Central

    Salma, Asem; Baidya, Nishanta B.; Wendt, Benjamin; Aguila, Francisco; Sammet, Steffen; Ammirati, Mario

    2011-01-01

    This study was conducted to investigate the radiological anatomy of the posterior clinoid process (PCP) to highlight preoperative awareness of its variations and its relationships to other skull base landmarks. The PCPs of 36, three-dimensional computed tomographic cadaveric heads were evaluated by studying the gross anatomy of the PCP and by measuring the distances between the PCP and other skull base anatomical landmarks relevant to transnasal or transcranial skull base approaches. PCP variations were found in five specimens (14%): in two the dorsum sellae was absent, in one the PCP and the anterior clinoid process (ACP) were connected unilaterally and in two bilaterally. The mean distance between the right/left PCP and the crista galli was 45.14 ± 4.0 standard deviation (SD_/46.24 ± 4.5 SD, respectively, while the distance to the middle point of the basion at the level of the foramen magnum was 40.41 ± 5.1 SD/41.0 ± 5.2 SD, respectively. The mean distance between the PCP and the ACP was 12.03 ± 3.18 SD on the right side and 12.11 ± 2.77 SD on the left. The data provided highlights the importance of careful preoperative evaluation of the PCP and of its relationships to other commonly encountered skull base landmarks. This information may give an idea of the exposure achievable through different transcranial and transnasal approaches. This is especially relevant when neuronavigation is not available. PMID:22547963

  17. Qualitative and quantitative radio-anatomical variation of the posterior clinoid process.

    PubMed

    Salma, Asem; Baidya, Nishanta B; Wendt, Benjamin; Aguila, Francisco; Sammet, Steffen; Ammirati, Mario

    2011-11-01

    This study was conducted to investigate the radiological anatomy of the posterior clinoid process (PCP) to highlight preoperative awareness of its variations and its relationships to other skull base landmarks. The PCPs of 36, three-dimensional computed tomographic cadaveric heads were evaluated by studying the gross anatomy of the PCP and by measuring the distances between the PCP and other skull base anatomical landmarks relevant to transnasal or transcranial skull base approaches. PCP variations were found in five specimens (14%): in two the dorsum sellae was absent, in one the PCP and the anterior clinoid process (ACP) were connected unilaterally and in two bilaterally. The mean distance between the right/left PCP and the crista galli was 45.14 ± 4.0 standard deviation (SD_/46.24 ± 4.5 SD, respectively, while the distance to the middle point of the basion at the level of the foramen magnum was 40.41 ± 5.1 SD/41.0 ± 5.2 SD, respectively. The mean distance between the PCP and the ACP was 12.03 ± 3.18 SD on the right side and 12.11 ± 2.77 SD on the left. The data provided highlights the importance of careful preoperative evaluation of the PCP and of its relationships to other commonly encountered skull base landmarks. This information may give an idea of the exposure achievable through different transcranial and transnasal approaches. This is especially relevant when neuronavigation is not available.

  18. Guided Application of Ventricular Catheters (GAVCA) - multicentre study to compare the ventricular catheter position after use of a catheter guide versus freehand application: study protocol for a randomised trail

    PubMed Central

    2013-01-01

    Background The standard technique for the placement of ventricular catheters (VC) comprises a high proportion of malpositioning of the catheter (12.5 to 40%). Technical advances such as neuronavigation or ultrasound have been shown to increase the accuracy of the procedure. Since these means result in significant technical and time consuming efforts, they are used for selected cases only. In order to simplify the controlled placement of ventricular catheters a newly developed smartphone assisted guiding tool has been introduced. In this study the efficacy and safety of this guiding tool is determined. Methods/design This study is a multicentre, randomised, controlled trial. A total of 144 patients planned for an elective shunting procedure will be enrolled throughout 10 study centres within two years. The primary objective of the trial is to show the superiority of the guided placement in comparison to the standard freehand technique of ventricular catheter application. Patients will be followed up for 30 days after the operation in regard to image-based evaluation of the catheter position as well as possible shunt dysfunction and complications. Discussion The Guided Application of Ventricular Catheters (GAVCA) trial compares the guided catheter positioning with the standard freehand technique of catheter placement in hydrocephalic patients. If superiority is shown, the standard technique may be changed with the advantage of a more reliable and safer positioning of the ventricular catheter with just a slight effort in time and pre-operative planning. Trial registration The GAVCA trial is registered at ClinicalTrials.gov under the number NCT01811589. PMID:24330776

  19. 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

  20. Surgical leg rotation: cortical neuroplasticity assessed through brain mapping using transcranial magnetic stimulation

    PubMed Central

    Benedetti, Maria Grazia; Rota, Viviana; Manfrini, Marco; Perucca, Laura; Caronni, Antonio

    2014-01-01

    Rotationplasty (Borggreve-Van Nes operation) is a rare limb salvage procedure, most often applied to children presenting with sarcoma of the distal femur. In type A1 operation, the distal thigh is removed and the proximal tibia is axially rotated by 180°, remodeled, grafted onto the femoral stump, and then prosthetized. The neurovascular bundle is spared. The rotated ankle then works as a knee. The foot plantar and dorsal flexors act as knee extensors and flexors, respectively. Functional results may be excellent. Cortical neuroplasticity was studied in three men (30–31 years) who were operated on the left lower limb at ages between 7 and 11 years and were fully autonomous with a custom-made prosthesis, as well as in three age–sex matched controls. The scalp stimulation coordinates, matching the patients’ brain MRI spots, were digitized through a ‘neuronavigation’ optoelectronic system, in order to guide the transcranial magnetic stimulation coil, thus ensuring spatial precision during the procedure. Through transcranial magnetic stimulation driven by neuronavigation, the cortical representations of the contralateral soleus and vastus medialis muscles were studied in terms of amplitude of motor evoked potentials (MEPs) and centering and width of the cortical areas from which the potentials could be evoked. Map centering on either hemisphere did not differ substantially across muscles and participants. In the operated patients, MEP amplitudes, the area from which MEPs could be evoked, and their product (volume) were larger for the muscles of the unaffected side compared with both the rotated soleus muscle (average effect size 0.75) and the muscles of healthy controls (average effect size 0.89). In controls, right–left differences showed an effect size of 0.38. In no case did the comparisons reach statistical significance (P>0.25). Nevertheless, the results seem consistent with cortical plasticity reflecting strengthening of the unaffected leg and a

  1. Persistent uncrossed corticospinal connections in patients with intractable focal epilepsy.

    PubMed

    Kaye, Harper L; Gersner, Roman; Boes, Aaron D; Pascual-Leone, Alvaro; Rotenberg, Alexander

    2017-10-01

    Corticospinal connections may be bilateral at birth, but a predominantly unilateral and crossed pattern develops by the toddler years. Acquired injury can alter the normal development of laterality such that uncrossed corticospinal connections persist, particularly if the injury is early in life and involves the motor system. Whether other developmental insults, such as childhood epilepsy, affect the development of crossed laterality in the motor system is unknown, although this topic has relevance for understanding the broader impact of epilepsy on brain development. Accordingly, in a cohort of children with intractable focal epilepsy, we tested by neuronavigated transcranial magnetic stimulation (nTMS) whether childhood epilepsy is associated with persistent uncrossed corticospinal connections. Specifically, we hypothesized that in contrast to early-life neuroclastic corticospinal tract injury that induces preservation of uncrossed corticospinal connections in the contralesional hemisphere, uncrossed corticospinal connections will be preserved in the epileptic hemisphere where the corticospinal tract is intact, but overstimulated by ongoing seizures and epileptic interictal discharges. Motor cortex mapping was performed by nTMS as part of a clinical presurgical evaluation, and the analysis was limited to patients with radiographically intact motor cortices and corticospinal tracts. Given that foot motor cortex representation is often bilateral, we focused on the lateralization for the tibialis anterior muscle cortical motor representation and its relation to the seizure focus. We demonstrate preserved uncrossed corticospinal connections for the tibialis anterior region of the hemisphere affected by the epilepsy. These findings indicate a pathologically preserved immature motor lateralization in patients with epilepsy and suggest that developmental processes associated with hemispheric lateralization are affected by epilepsy. Copyright © 2017. Published by

  2. Personalizing the Electrode to Neuromodulate an Extended Cortical Region.

    PubMed

    Cancelli, A; Cottone, C; Di Giorgio, M; Carducci, F; Tecchio, F

    2015-01-01

    Among transcranial electric stimulation (tES) parameters, personalizing the electrode geometry might help overcome the individual variability of the induced effects. To test the need for electrode personalization, instead of a universal electrode for everyone, to induce neuromodulation effects on the bilateral primary motor cortex (M1) devoted to upper and lower limb representation. By an ad-hoc neuronavigation procedure, we shaped the personalized electrode and positioned it matching the projection on the scalp of the individual central sulcus by a 2 cm strip, with total area of 35 cm(2). The non-personalized electrode, i.e., equal for all subjects, was a 2 cm wide strip size-matched with the personalized electrode but shaped on a standard model fitting the curve passing through C3-CZ-C4 sites of the electroencephalographic (EEG) 10-20 International System. To test neuromodulation electrode-dependent efficacy, we induced a 20 Hz sinusoidal modulated current (transcranial alternating current stimulation, tACS) because it produces online effects. We simultaneously collected left and right hand and leg motor potentials (MEP) that were evoked by a rounded transcranial magnetic stimulation (TMS) coil. Through each electrode we delivered both real and sham stimulations. While cortical excitability during tACS increased during both the non-personalized and the personalized electrodes for the leg, the hand representation excitability enhancement was induced selectively when using the personalized electrode. The results were consistent bilaterally. We documented that by using a personalized electrode it is possible to induce the neuromodulation of a predetermined extended cortical target, which did not occur with a non-personalized electrode. Our findings can help in building neuromodulation methods that might compensate for individual alterations across specific brain networks. Copyright © 2015 Elsevier Inc. All rights reserved.

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

    PubMed Central

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

    2016-01-01

    OBJECTIVE 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. METHODS 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. RESULTS 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 de-bulking 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. CONCLUSIONS 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

  4. 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

  5. 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.

  6. Electrophysiological and Anatomical Correlates of Spinal Cord Optical Coherence Tomography

    PubMed Central

    Valente, Maurizio; Krstajic, Nikola; Biella, Gabriele E. M.

    2016-01-01

    Despite the continuous improvement in medical imaging technology, visualizing the spinal cord poses severe problems due to structural or incidental causes, such as small access space and motion artifacts. In addition, positional guidance on the spinal cord is not commonly available during surgery, with the exception of neuronavigation techniques based on static pre-surgical data and of radiation-based methods, such as fluoroscopy. A fast, bedside, intraoperative real-time imaging, particularly necessary during the positioning of endoscopic probes or tools, is an unsolved issue. The objective of our work, performed on experimental rats, is to demonstrate potential intraoperative spinal cord imaging and probe guidance by optical coherence tomography (OCT). Concurrently, we aimed to demonstrate that the electromagnetic OCT irradiation exerted no particular effect at the neuronal and synaptic levels. OCT is a user-friendly, low-cost and endoscopy-compatible photonics-based imaging technique. In particular, by using a Fourier-domain OCT imager, operating at 850 nm wavelength and scanning transversally with respect to the spinal cord, we have been able to: 1) accurately image tissue structures in an animal model (muscle, spine bone, cerebro-spinal fluid, dura mater and spinal cord), and 2) identify the position of a recording microelectrode approaching and inserting into the cord tissue 3) check that the infrared radiation has no actual effect on the electrophysiological activity of spinal neurons. The technique, potentially extendable to full three-dimensional image reconstruction, shows prospective further application not only in endoscopic intraoperative analyses and for probe insertion guidance, but also in emergency and adverse situations (e.g. after trauma) for damage recognition, diagnosis and fast image-guided intervention. PMID:27050096

  7. 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

  8. Intraoperative tractography and motor evoked potential (MEP) monitoring in surgery for gliomas around the corticospinal tract.

    PubMed

    Maesawa, Satoshi; Fujii, Masazumi; Nakahara, Norimoto; Watanabe, Tadashi; Wakabayashi, Toshihiko; Yoshida, Jun

    2010-07-01

    Our goal is to indicate the importance of combining intraoperative tractography with motor-evoked potential (MEP) monitoring for glioma surgery in motor eloquent areas. Tumor removal was performed in 28 patients with gliomas in and around the corticospinal tract (CST), in an operation theater equipped with an integrated high-field intraoperative magnetic resonance imaging and a neuronavigation system. Diffusion-tensor imaging-based tractography of the CST was implemented preoperatively and intraoperatively. When the surgically manipulated area came close to the corticospinal pathway, MEP responses were elicited by subcortical stimulation. Responsive areas were compared with the locations of fibers traced by preoperative and intraoperative tractography. Imaging and functional outcomes were reviewed. Intraoperative tractography demonstrated significant inward or outward shift during surgery. MEP responses were observed around the tract at various intensities, and the distance between MEP responsive sites and intraoperative tractography was significantly correlated with the stimulation intensity (P < 0.01). The distance from preoperative tractography was not correlated. A more than subtotal resection was achieved in 24 patients (85.7%). Transient motor deterioration was seen in 12 patients (42.8%), and a permanent deficit was seen in 1 patient (3.5%). We found that intraoperative tractography demonstrated the location of the CST more accurately than preoperative tractography. The results of the linear regression between distance and stimulation intensity were informative for guiding approaches to tumor remnants without impinging on the CST. The combination of intraoperative tractography and MEP monitoring can enhance the quality of surgery for gliomas in motor eloquent areas. Copyright © 2010 Elsevier Inc. All rights reserved.

  9. Intraoperative resection control using arterial spin labeling - Proof of concept, reproducibility of data and initial results.

    PubMed

    Lindner, Thomas; Ahmeti, Hajrullah; Lübbing, Isabel; Helle, Michael; Jansen, Olav; Synowitz, Michael; Ulmer, Stephan

    2017-01-01

    Intraoperative magnetic resonance imaging is a unique tool for visualizing structures during resection and/or for updating any kind of neuronavigation that might be hampered as a result of brain shift during surgery. Advanced MRI techniques such as perfusion-weighted imaging have already proven to be important in the initial diagnosis preoperatively, but can also help to differentiate between tumor and surgically induced changes intraoperatively. Commonly used methods to visualize brain perfusion include contrast agent administration and are therefore somewhat limited. One method that uses blood as an internal contrast medium is arterial spin labeling (ASL), which might represent an attractive alternative. Ten healthy volunteers were examined using three different scanners and coils within 1 h (3T Achieva MRI using 32-channel head coil, 1.5T Achieva MRI using a 6-channel head coil, 1.5 Intera Scanner using 2 surface coils, Philips, Best, The Netherlands) and quantitative CBF values were calculated and compared between the different setups. Additionally, in eight patients with glioblastoma multiforme, ASL was used pre-, intra-, and postoperatively to define tumor tissue and the extent of resection in comparison to structural imaging. A high correlation (r = 0.91-0.96) was found between MRI scanners and coils used. ASL was as reliable as conventional MR imaging if complete resection was already achieved, but additionally provided valuable information regarding residual tumor tissue in one patient. Intraoperative arterial spin-labeling is a feasible, reproducible, and reliable tool to map CBF in brain tumors and seems to give beneficial information compared to conventional intraoperative MR imaging in partial resection.

  10. What is the Surgical Benefit of Utilizing 5-Aminolevulinic Acid for Fluorescence-Guided Surgery of Malignant Gliomas?

    PubMed

    Hadjipanayis, Costas G; Widhalm, Georg; Stummer, Walter

    2015-11-01

    The current neurosurgical goal for patients with malignant gliomas is maximal safe resection of the contrast-enhancing tumor. However, a complete resection of the contrast-enhancing tumor is achieved only in a minority of patients. One reason for this limitation is the difficulty in distinguishing viable tumor from normal adjacent brain during surgery at the tumor margin using conventional white-light microscopy. To overcome this limitation, fluorescence-guided surgery (FGS) using 5-aminolevulinic acid (5-ALA) has been introduced in the treatment of malignant gliomas. FGS permits the intraoperative visualization of malignant glioma tissue and supports the neurosurgeon with real-time guidance for differentiating tumor from normal brain that is independent of neuronavigation and brain shift. Tissue fluorescence after oral administration of 5-ALA is associated with unprecedented high sensitivity, specificity, and positive predictive values for identifying malignant glioma tumor tissue. 5-ALA-induced tumor fluorescence in diffusely infiltrating gliomas with non-significant magnetic resonance imaging contrast-enhancement permits intraoperative identification of anaplastic foci and establishment of an accurate histopathological diagnosis for proper adjuvant treatment. 5-ALA FGS has enabled surgeons to achieve a significantly higher rate of complete resections of malignant gliomas in comparison with conventional white-light resections. Consequently, 5-ALA FGS has become an indispensable surgical technique and standard of care at many neurosurgical departments around the world. We conducted an extensive literature review concerning the surgical benefit of using 5-ALA for FGS of malignant gliomas. According to the literature, there are a number of reasons for the neurosurgeon to perform 5-ALA FGS, which will be discussed in detail in the current review.

  11. Feasibility of fluorescence-guided resection of recurrent gliomas using five-aminolevulinic acid: retrospective analysis of surgical and neurological outcome in 58 patients.

    PubMed

    Hickmann, Anne-Katrin; Nadji-Ohl, Minou; Hopf, Nikolai J

    2015-03-01

    Five-aminolevulinic-acid (5-ALA) is known for its benefits in surgery of primary gliomas, but has only been cautiously used in recurrent gliomas dreading over-resection, insufficient or false-positive fluorescence in adjuvantly treated tumors. We evaluated intraoperative fluorescence based on tumor pathology, pretreatment as well as surgical and neurological outcome in patients with recurrent gliomas. Patients who underwent fluorescence-guided surgery for recurrent gliomas between 6/2010 and 2/2014 at our institution were retrospectively selected. Degree of surgical resection, neurological status, pathology results, intraoperative fluorescence and follow up status were analyzed. Patients who underwent repeat surgery without 5-ALA were selected as controls. 58 patients with high grade gliomas (°III and °IV) were included. 10 of 63 tumors (15.9 %) failed to fluoresce intraoperatively of which nine (90 %) had been adjuvantly treated prior to recurrence, as were 46 of the 53 fluorescing tumors (86.8 %). Non-fluorescing tumors were IDH mutated significantly more often (p = 0.005). 30 tumors (47.6 %) were located eloquently. 51 (80.9 %) patients showed no new neurologic deficits postoperatively. 13 patients (20.6 %) showed no signs of recurrence at their latest follow up. Eight patients were lost to follow up. Overall survival was significantly longer in the 5-ALA group (p = 0.025). Fluorescence-guided surgery in recurrent gliomas is safe and allows for a good surgical and neurological outcome in a difficult surgical environment, especially when used in combination with neuronavigation and intraoperative ultrasound to prevent over-resection. Adjuvant therapy did not significantly influence fluorescing properties.

  12. 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

  13. Complex technical methodologies and their applications in the surgery of intracranial meningiomas.

    PubMed

    Chen, T C; Rabb, C; Apuzzo, M L

    1994-04-01

    As neurosurgery moves into the twenty-first century, improved visualization/localization techniques, neuromonitoring, and advanced instrumentation will become standards of care for all intracranial procedures. This article has focused on current available technologies that can be used to facilitate operations on intracranial meningiomas. Preoperative anatomic localization with MR imaging, CT, MR angiography, and angiography are standard techniques. Preoperative functional assessments with MR imaging, magnetic source imaging, PET, and functional MR imaging are crucial to recognize and preserve eloquent adjacent cortex. Pathologic correlations with preoperative imaging (i.e., MR imaging) may help to predict the histopathology. Perioperative rehearsal of the operation can be performed. Intraoperative anatomic localization is important to minimize the craniotomy, dural opening, and passage through normal neural structures. An impressive array of new technologies are currently available, including real-time ultrasonography, frame-based stereotaxy (CT, MR imaging PET), frameless stereotaxy (acoustic localization, neuronavigators, real-time visualization), robotics, neuroendoscopy, and intraoperative dye administration. Increased understanding of the function and individual variability of the human cortex underscores the importance of intraoperative functional localization by electrocorticography and optical imaging. Continuous intraoperative neuromonitoring of sensory (SSEPs, BAERs, visual evoked potentials) and motor evoked potentials is now standard during many intracranial procedures. Complex adjunctive instrumentation, such as the ultrasonic aspirator and the laser, are part of the contemporary armamentarium for meningioma surgery. As we have stated in a previous article, "Developmental trends imply realization of three major directions of technical neurosurgery: (1) precise preoperative simulation, (2) minimization or avoidance of transcranial operative corridors

  14. Pre-surgical evaluation and surgical treatment in children with extratemporal epilepsy.

    PubMed

    Centeno, Ricardo Silva; Yacubian, Elza Marcia; Sakamoto, Americo Ceiki; Ferraz, Antonio Fernando Patriani; Junior, Henrique Carrete; Cavalheiro, Sergio

    2006-08-01

    This review summarizes some patterns of pre-surgical evaluation and surgical treatment of extratemporal epilepsy in pediatric patients with medically refractory seizures, whose ictal behavior is variable. The most effective treatment for intractable partial epilepsy is a focal cortical resection with excision of the epileptogenic zone (the area of ictal onset and initial seizure propagation). This might be risky, though, in the case of a widespread lesion, sometimes encroaching one or more lobes, given the risk to the functional cerebral cortex. An anterior temporal lobectomy might prove more effective then in preventing seizures with fewer potential complications. If partial extratemporal epilepsy is associated with pharmaco-resistant seizures, the preoperative evaluation and operative strategy are determined according to the epileptogenic zone and to the relationship between a substrate-directed disorder and eloquent areas. The pediatric treatment of extratemporal epilepsy is aimed at controlling the seizures, avoiding morbidity, and improving the patient's quality of life through psychosocial integration. Since the immature brain is more plastic than when mature, the recovery of functions after surgery is greater in children than in adults. Early surgery is recommended for children with intractable epilepsy, and is now accepted as an important therapeutic modality also for children with chronic epilepsy. Technological advances in the last two decades, mainly in neuroimaging, have led many medical centers to consider surgical treatment of epilepsy, accuracy being granted by MRI-based neuronavigation systems-an interface between the lesion seen in the preoperative magnetic resonance imaging (MRI) and the operative field, often invisible to the surgeon.

  15. On the cerebral origin of EEG responses to TMS: insights from severe cortical lesions.

    PubMed

    Gosseries, Olivia; Sarasso, Simone; Casarotto, Silvia; Boly, Mélanie; Schnakers, Caroline; Napolitani, Martino; Bruno, Marie-Aurélie; Ledoux, Didier; Tshibanda, Jean-Flory; Massimini, Marcello; Laureys, Steven; Rosanova, Mario

    2015-01-01

    Transcranial magnetic stimulation combined with electroencephalography (TMS/EEG) represents a valuable tool to probe cortical excitability and connectivity. Although several procedures have been devised to abolish TMS-related artifacts, direct evidence that it is possible to record TMS-evoked potentials (TEPs) that purely reflect cortical responses to TMS are still lacking. To demonstrate that when TMS is delivered on a human head with intact nerves, scalp and ocular muscles, TEPs are present only if a functional portion of cortex is targeted and is absent otherwise. We performed extensive navigated TMS/EEG mappings in three vegetative state patients and in eight healthy controls. Patients were selected based on the extension of their cortical lesions as revealed by structural/functional imaging: the cerebral cortex was globally damaged in Patient 1 due to cerebral anoxia, Patient 2 showed a traumatic damage affecting one cerebral hemisphere, while Patient 3 was characterized by one left sided and one right-sided focal ischemic lesion. In Patient 1, TMS performed at any targeted cortical site did not elicit statistically significant TEPs. In Patient 2, TEPs were absent when the damaged hemisphere was targeted, while were present over the healthy side. In Patient 3, significant TEPs were absent when cortical lesions were targeted and present otherwise. Significant TEPs were always present in healthy controls. These findings suggest that, provided that appropriate experimental procedures are employed, TEPs are genuine cortical responses detectable only when preserved cortical tissue is stimulated. Hence, a dependable assessment of cortical excitability and connectivity in brain-injured patients requires the use of neuronavigated TMS. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. 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.

  17. 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.

  18. Suprasellar pediatric craniopharyngioma resection via endonasal endoscopic approach.

    PubMed

    Ali, Zarina S; Lang, Shih-Shan; Kamat, Ameet R; Adappa, Nithin D; Palmer, James N; Storm, Phillip B; Lee, John Y K

    2013-11-01

    Purely endoscopic endonasal approaches to surgical resection of pediatric suprasellar craniopharyngiomas are uncommonly performed. The aim of the study is to assess the feasibility and to describe the short-term outcomes of endonasal endoscopic approaches for the gross total resection of suprasellar craniopharyngiomas in the pediatric population. A combined neurosurgical-otolaryngologic team performed gross total resection of craniopharyngiomas in seven pediatric patients (mean age 9.6 years) at The Children's Hospital of Philadelphia over 2011-2012. Short-term outcomes were analyzed over a mean follow-up period of 6.3 months. All tumors involved the sellar and/or suprasellar space and contained some cystic component. The mean maximal tumor diameter was 31.5 mm (range 18.5-62.0 mm). Using a binostril approach, gross total tumor resection was obtained in all patients (100 %). All patients with preoperative visual dysfunction demonstrated improvement in visual acuity. New or stable panhypopituitarism was observed in all cases. All patients developed postoperative diabetes insipidus, and cerebrospinal fluid leak occurred in one patient (15 %). Complete radiographic resection of pediatric craniopharyngioma can be achieved via a purely endoscopic endonasal approach. In particular, this approach can be performed safely using the "two-nostrils-four-hands" technique with intraoperative neuronavigation. This approach should be highly considered in patients with progressive visual dysfunction. Further studies are needed to characterize the long-term surgical and clinical outcome of pediatric patients treated with this surgical approach.

  19. Usefulness of the indocyanine green fluorescence endoscope in endonasal transsphenoidal surgery.

    PubMed

    Hide, Takuichiro; Yano, Shigetoshi; Shinojima, Naoki; Kuratsu, Jun-ichi

    2015-05-01

    To avoid disorientation during endoscopic endonasal transsphenoidal surgery (ETSS), the confirmation of anatomical landmarks is essential. Neuronavigation systems can be pointed at exact sites, but their spatial resolution power is too low for the detection of vessels that cannot be seen on MR images. On Doppler ultrasonography the shape of concealed arteries and veins cannot be visualized. To address these problems, the authors evaluated the clinical usefulness of the indocyanine green (ICG) endoscope. The authors included 38 patients with pituitary adenomas (n = 26), tuberculum sellae meningiomas (n = 4), craniopharyngiomas (n = 3), chordomas (n = 2), Rathke's cleft cyst (n = 1), dermoid cyst (n = 1), or fibrous dysplasia (n = 1). After opening the sphenoid sinus and placing the ICG endoscope, the authors injected 12.5 mg of ICG into a peripheral vein as a bolus and observed the internal carotid arteries (ICAs), cavernous sinus, intercavernous sinus, and pituitary. The ICA was clearly identified by a strong fluorescence signal through the dura mater and the covering thin bone. The intercavernous and cavernous sinuses were visualized a few seconds later. In patients with tuberculum sellae meningiomas, the abnormal tumor arteries in the dura were seen and the vague outline of the attachment was identified. At the final inspection after tumor removal, perforators to the brain, optic nerves, chiasm, and pituitary stalk were visualized. ICG fluorescence signals from the hypophyseal arteries were strong enough to see and spread to the area of perfusion with the passage of time. The ICA and the patent cavernous sinus were detected with the ICG endoscope in real time and at high resolution. The ICG endoscope is very useful during ETSS. The authors suggest that the real-time observation of the blood supply to the optic nerves and pituitary helps to predict the preservation of their function.

  20. Shortening the learning curve in endoscopic endonasal skull base surgery: a reproducible polymer tumor model for the trans-sphenoidal trans-tubercular approach to retro-infundibular tumors.

    PubMed

    Berhouma, Moncef; Baidya, Nishanta B; Ismaïl, Abdelhay A; Zhang, Jun; Ammirati, Mario

    2013-09-01

    Endoscopic endonasal skull base surgery attracts an increasing number of young neurosurgeons. This recent technique requires specific technical skills for the approaches to non-pituitary tumors (expanded endoscopic endonasal surgery). Actual residents' busy schedules carry the risk of compromising their laboratory training by limiting significantly the dedicated time for dissections. To enhance and shorten the learning curve in expanded endoscopic endonasal skull base surgery, we propose a reproducible model based on the implantation of a polymer via an intracranial route to provide a pathological retro-infundibular expansive lesion accessible to a virgin expanded endoscopic endonasal route, avoiding the ethically-debatable need to hundreds of pituitary cases in live patients before acquiring the desired skills. A polymer-based tumor model was implanted in 6 embalmed human heads via a microsurgical right fronto-temporal approach through the carotido-oculomotor cistern to mimic a retro-infundibular tumor. The tumor's position was verified by CT-scan. An endoscopic endonasal trans-sphenoidal trans-tubercular trans-planum approach was then carried out on a virgin route under neuronavigation tracking. Dissection of the tumor model from displaced surrounding neurovascular structures reproduced live surgery's sensations and challenges. Post-implantation CT-scan allowed the pre-removal assessment of the tumor insertion, its relationships as well as naso-sphenoidal anatomy in preparation of the endoscopic approach. Training on easily reproducible retro-infundibular approaches in a context of pathological distorted anatomy provides a unique opportunity to avoid the need for repetitive live surgeries to acquire skills for this kind of rare tumors, and may shorten the learning curve for endoscopic endonasal surgery. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. How I do it: the endoscopic endonasal optic nerve and orbital apex decompression.

    PubMed

    Jacquesson, Timothée; Abouaf, Lucie; Berhouma, Moncef; Jouanneau, Emmanuel

    2014-10-01

    With the refinement of the technique, endoscopic endonasal surgery increases its field of indications. The orbital compartment is among the locations easily reached through the nostril. This anteromedial approach has been described primarily for inflammatory or traumatic diseases, with few data for tumoral diseases. Since 2010, this route has been used at our institution either for decompression or for biopsy of orbital tumoral diseases. Even if further studies are warranted, this strategy proved to be beneficial for patients, with improvements in visual outcome. In this article, the authors summarize their technique and their experience with endonasal endoscopic orbital decompression. Nasal and sphenoidal anatomies determine the feasibility and risks for doing an efficient medial optic or orbit decompression. • Techniques and tools used are those developed for pituitary surgery. • A middle turbinectomy and posterior ethmoidectomy are mandatory to expose the medial wall of the orbit. • The Onodi cell is a key marker for the optic canal and must be opened up with caution. • The lamina papyracea is opened first with a spatula and the optic canal opened up by a gentle drilling under continuous irrigation from distal to proximal. • Drilling might always be used under continuous irrigation to avoid overheating of the optic nerve. An ultrasonic device can be used as well. • The nasal corridor is narrow and instruments may hide the infrared neuronavigation probe. To overcome this issue, a magnetic device could be useful. • Doppler control could be useful to locate the ICA. • The optic canal must be opened up from the tuberculum of the sella to the orbital apex and from the planum (anterior cranial fossa) to the lateral OCR or ICA canal • At the end of the procedure, the optic nerve becomes frequently pulsatile, which is a good marker of decompression.

  2. Analysis of 137 Patients Who Underwent Endoscopic Transsphenoidal Pituitary Adenoma Resection Under High-Field Intraoperative Magnetic Resonance Imaging Navigation.

    PubMed

    Zhang, Huaping; Wang, Fuyu; Zhou, Tao; Wang, Peng; Chen, Xiaolei; Zhang, Jiashu; Zhou, Dingbiao

    2017-08-01

    Pure endoscopic resection has become the most popular surgical approach for pituitary adenoma. Intraoperative magnetic resonance imaging (iMRI) systems have been in use for endoscopic resection of pituitary adenomas. This study aimed to evaluate the effectiveness of iMRI and neuroimaging navigation techniques during endoscopic endonasal transsphenoidal surgery of pituitary adenomas. Data from 137 patients who underwent resection of endoscopic pituitary adenoma under 1.5T iMRI navigation were collected and analyzed. Of patients, 92 underwent complete resection and 45 had residual tumor on real-time iMRI. Twenty-three patients underwent further surgery, and total resection was achieved in 19. Extent of total resection increased from 67.15% to 81.02%. iMRI revealed 3 patients with bleeding in the surgical area, which was successfully treated during the surgery. Review images obtained 3 months after surgery showed 26 patients with residual tumor; 14 patients had the same volume as intraoperatively, and 12 patients had a volume less than that observed intraoperatively. Residual tumor volume in the suprasellar region was less than that seen intraoperatively in 11 of 15 (73.3%) patients. The use of iMRI and neuronavigation not only leads to a higher rate of tumor resection but also helps in detecting and removing hematomas in the surgical area. Follow-up examinations of extent of residual tumor at 3 months postoperatively were consistent with intraoperative results. Residual tumor volume in the suprasellar region was usually less than that observed intraoperatively. Copyright © 2017. Published by Elsevier Inc.

  3. Anatomic skull base education using advanced neuroimaging techniques.

    PubMed

    de Notaris, Matteo; Topczewski, Thomaz; de Angelis, Michelangelo; Enseñat, Joaquim; Alobid, Isam; Gondolbleu, Amer Mustafa; Soria, Guadalupe; Gonzalez, Joan Berenguer; Ferrer, Enrique; Prats-Galino, Alberto

    2013-02-01

    The goal of the present article was to describe our dissection training system applied to a variety of endoscopic endonasal approaches. It allows one to perform a 3D virtual dissection of the desired approach and to analyze and quantify critical surgical measurements. All the human cadaveric heads were dissected at the Laboratory of Surgical Neuro-Anatomy (LSNA) of the University of Barcelona (Spain). The model surgical training protocol was designed as follows: 1) virtual dissection of the selected approach using our dissection training 3D model; 2) preliminary exploration of each specimen using a second 3D model based on a preoperative computed tomographic scan; 3) cadaveric anatomic dissection with the aid of a neuronavigation system; and 4) quantification and analysis of the collected data. The virtual dissection of the selected approach, preliminary exploration of each specimen, a real laboratory dissection experience, and finally, the analysis of data retrieved during the dissection step was a complete method for training manual dexterity and hand-eye coordination and to improve the general knowledge of surgical approaches. The present model results are found to be effective, providing a valuable representation of the surgical anatomy as well as a 3D visual feedback, thus improving study, design, and execution in a variety of approaches. Such a system can also be developed as a preoperative planning tool that will allow the neurosurgeon to practice and manipulate 3D representations of the critical anatomic landmarks involved in the endoscopic endonasal approaches to the skull base. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Role of endoscopic third ventriculostomy in tuberculous meningitis with hydrocephalus

    PubMed Central

    Yadav, Yad R.; Parihar, Vijay S.; Todorov, Mina; Kher, Yatin; Chaurasia, Ishwar D.; Pande, Sonjjay; Namdev, Hemant

    2016-01-01

    Hydrocephalus is one of the commonest complications of tuberculous meningitis (TBM). It can be purely obstructive, purely communicating, or due to combinations of obstruction in addition to defective absorption of cerebrospinal fluid (CSF). Endoscopic third ventriculostomy (ETV) as an alternative to shunt procedures is an established treatment for obstructive hydrocephalus in TBM. ETV in TBM hydrocephalus can be technically very difficult, especially in acute stage of disease due to inflamed, thick, and opaque third ventricle floor. Water jet dissection can be helpful in thick and opaque ventricular floor patients, while simple blunt perforation is possible in thin and transparent floor. Lumbar peritoneal shunt is a better option for communicating hydrocephalus as compared to VP shunt or ETV. Intraoperative Doppler or neuronavigation can help in proper planning of the perforation to prevent neurovascular complications. Choroid plexus coagulation with ETV can improve success rate in infants. Results of ETV are better in good grade patients. Poor results are observed in cisternal exudates, thick and opaque third ventricle floor, acute phase, malnourished patients as compared to patients without cisternal exudates, thin and transparent third ventricle floor, chronic phase, well-nourished patients. Some of the patients, especially in poor grade, can show delayed recovery. Failure to improve after ETV can be due to blocked stoma, complex hydrocephalus, or vascular compromise. Repeated lumbar puncture can help faster normalization of the raised intracranial pressure after ETV in patients with temporary defect in CSF absorption, whereas lumbar peritoneal shunt is required in permanent defect. Repeat ETV is recommended if the stoma is blocked. ETV should be considered as treatment of choice in chronic phase of the disease in obstructive hydrocephalus. PMID:27695532

  5. Magnetic resonance imaging and histology correlation in Cushing's disease.

    PubMed

    Masopust, Václav; Netuka, David; Beneš, Vladimír; Májovský, Martin; Belšán, Tomáš; Bradáč, Ondřej; Hořínek, Daniel; Kosák, Mikuláš; Hána, Václav; Kršek, Michal

    We continuously look for new techniques to improve the radicality of resection and to eliminate the negative effects of surgery. One of the methods that has been implemented in the perioperative management of Cushing's disease was the combination of three magnetic resonance imaging (MRI) sequences: SE, SPGR and fSPGR. We enrolled 41 patients (11 males, 30 females) diagnosed with Cushing's disease. A 3D tumour model with a navigation console was developed using each SPGR, fSPGR and SE sequence. The largest model was then used. In all cases, a standard four-handed, bi-nostril endoscopic endonasal technique was used. Endocrinological follow-up evaluation using morning cortisol sampling was performed for 6-34 months in our study. In total, 36 patients (88%) were disease-free following surgery. Our results indicate we achieved 100% sensitivity of MR. Overall, the conformity of at least one donor site, as compared with the places designated on MR, was in 78% of patients. We searched the place of compliance in individual locations. There is a consensus in individual locations in 63 of the 123 cases (or 56%). The correlation gamma function at a 5% significance level was then 0.27. The combination of MR sequences (SE, SPGR, fSPGR), neuronavigation system and iMRI led to increased sensitivity of up to 100%. Specificity reached 56% in our study. We found a high success rate in surgical procedure in terms of the correlation between MR findings and histology, which leads to remission of Cushing's disease. Copyright © 2016. Published by Elsevier Urban & Partner Sp. z o.o.

  6. 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.

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

    PubMed Central

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

    2015-01-01

    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. PMID:27190736

  8. World Health Organization Grade I Convexity Meningiomas: Study on Outcomes, Complications and Recurrence Rates.

    PubMed

    Nanda, Anil; Bir, Shyamal C; Konar, Subhas; Maiti, Tanmoy K; Bollam, Papireddy

    2016-05-01

    The clinical significance of the Simpson grading system of extent of meningioma resection and its role as a predictor for recurrence of World Health Organization (WHO) grade I meningiomas have been questioned in the past, as microsurgery and knowledge of pathologic details have advanced. Clinical and radiologic information on 112 patients with WHO grade I convexity meningiomas who underwent surgery over the past 20 years was retrospectively reviewed. The recurrence rate in the grade 0-I resection group was 2.9%, whereas in the grade II-IV resection group, the recurrence rate was 31% (P = 0.0001). In Cox regression analysis, Simpson grade 0-I resection was revealed as a significant predictor of recurrence-free survival (P = 0.021). The hazard ratio for recurrence after II-IV resection was 10.98 times higher than grade 0-I. Like the Simpson grading of resection, a similar trend of recurrence (grade I, 1.6% vs. grade II-IV, 28%, P = 0.0001) was observed in the Shinshu grade of resection. In univariate analysis, female gender and use of neuronavigation were also identified as independent predictors of recurrence-free survival after resection of WHO grade I meningiomas. Six months after surgery, use of antiepileptic medication was less in grade 0-I compared with other grades. When histologic grade is fixed, the Simpson grading system is the prime predictor for recurrence of meningioma after resection. Grade 0-I resection is also beneficial in cutting off antiepileptic medication in patients with convexity meningiomas. Although complete tumor resection (grade 0-I) is the goal, the surgical approach should be tailored to each patient depending on the risks and surgical morbidity. Published by Elsevier Inc.

  9. 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.

  10. 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.

  11. Intraoperative diffusion-weighted imaging for visualization of the pyramidal tracts. Part II: clinical study of usefulness and efficacy.

    PubMed

    Ozawa, N; Muragaki, Y; Nakamura, R; Lseki, H

    2008-04-01

    Precise identification and preservation of the pyramidal tract during surgery for parenchymal brain tumors is of crucial importance for the avoidance of postoperative deterioration of the motor function. The technique of intraoperative diffusion-weighted imaging (iDWI) using an intraoperative MR scanner of low magnetic field strength (0.3 Tesla) has been developed. Its clinical usefulness and efficacy were evaluated in 10 surgically treated patients with gliomas (5 men and 5 women, mean age: 41.2+/-13.9 years). iDWI permitted visualization of the pyramidal tract on the non-affected side in all 10 cases, and on the affected side in 8 cases. Motion artifacts were observed in four patients, but were not an obstacle to identification of the pyramidal tract. Good correspondence of the anatomical landmarks localization on iDWI and T (1)-weighted imaging was found. All participating neurosurgeons agreed that, in the majority of cases, iDWI was very useful for localization of the pyramidal tract and for clarification of its spatial relationships with the tumor. In conclusion, image quality and accuracy of the iDWI obtained with an MR scanner of low magnetic field strength (0.3 Tesla) are sufficient for possible incorporation into an intraoperative neuronavigation system. The use of iDWI in addition to structural iMRl and subcortical functional mapping with electrical stimulation can potentially result in a reduction of the postoperative morbidity after aggressive surgical removal of lesions located in the vicinity to the motor white matter tracts.

  12. 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.

  13. 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

  14. Virtual MRI endoscopy: detection of anomalies of the ventricular anatomy and its possible role as a presurgical planning tool for endoscopic third ventriculostomy.

    PubMed

    Rohde, V; Krombach, G A; Struffert, T; Gilsbach, J M

    2001-11-01

    Many anatomical anomalies have the potential to impair the efficacy of endoscopic third ventriculostomy (ETV) and increase the surgical morbidity. By virtual magnetic resonance imaging (MRI) endoscopy, the real endoscopic view into the ventricular system can be simulated. It was the objective of the present study to investigate if this simulation is sensitive enough to detect anatomical anomalies of the ventricular system. In 18 hydrocephalic patients, first neuronavigationally guided ETV, then virtual MRI endoscopy were performed. This study design allowed for selection of a path for virtual MRI endoscopy, which was identical to that used during surgery, making the real and the virtual view on anatomical structures of the ventricular system highly comparable. It was investigated whether the intra-operatively identified anatomical anomalies could likewise be depicted on virtual MR endoscopic images. Seven anatomical variants (not enlarged interventricular foramen n=2, atrophic corpus callosum and split fornical bodies n=1, narrow retroclival space n=1, prominent basilar tip n=1, opaque and thick/atypically declining third ventricular floor n=2) were encountered in 5 of the 18 patients during surgery. The five variants of the non-membraneous structures were identified by virtual MRI endoscopy (sensitivity 71%), whereas the anatomical variants of the third ventricular floor were missed. Both the normal as well as the variant third ventricular floor could not be visualised and appeared as a defect. Through this artefact, the anatomy of the major vessels in the interpeduncular cistern could be assessed. The sensitivity of virtual MRI endoscopy for detection of anatomical variants of the ventricular system is low. Its potential usefulness as a presurgical planning tool inspite of this low sensitivity rate is discussed.

  15. 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.

  16. An integrated model-based neurosurgical guidance system

    NASA Astrophysics Data System (ADS)

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

    2010-02-01

    Maximal tumor resection without damaging healthy tissue in open cranial surgeries is critical to the prognosis for patients with brain cancers. Preoperative images (e.g., preoperative magnetic resonance images (pMR)) are typically used for surgical planning as well as for intraoperative image-guidance. However, brain shift even at the start of surgery significantly compromises the accuracy of neuronavigation, if the deformation is not compensated for. Compensating for brain shift during surgical operation is, therefore, critical for improving the accuracy of image-guidance and ultimately, the accuracy of surgery. To this end, we have developed an integrated neurosurgical guidance system that incorporates intraoperative three-dimensional (3D) tracking, acquisition of volumetric true 3D ultrasound (iUS), stereovision (iSV) and computational modeling to efficiently generate model-updated MR image volumes for neurosurgical guidance. The system is implemented with real-time Labview to provide high efficiency in data acquisition as well as with Matlab to offer computational convenience in data processing and development of graphical user interfaces related to computational modeling. In a typical patient case, the patient in the operating room (OR) is first registered to pMR image volume. Sparse displacement data extracted from coregistered intraoperative US and/or stereovision images are employed to guide a computational model that is based on consolidation theory. Computed whole-brain deformation is then used to generate a model-updated MR image volume for subsequent surgical guidance. In this paper, we present the key modular components of our integrated, model-based neurosurgical guidance system.

  17. Anterior single odontoid screw placement for type II odontoid fractures: our modified surgical technique and initial results in a cohort study of 15 patients

    PubMed Central

    Munakomi, Sunil; Tamrakar, Karuna; Chaudhary, Pramod Kumar; Bhattarai, Binod

    2016-01-01

    Objective: Anterior odontoid screw fixation for type II odontoid fracture is the ideal management option. However in the context of unavailability of an O-arm or neuro-navigation and poor images from the available C-arm may be an obstacle to ideal trajectory and placement of the odontoid screw. We herein detail  our surgical technique so as to ensure a correct trajectory and subsequent good fusion in Type II odontoid fractures. This may be advantageous  in clinical set ups lacking state of the art facilities.  Methods and Results: In this cohort study we included 15 consecutive patients who underwent anterior odontoid screw placement. We routinely dissect the longus colli to completely visualize the entire width of C3 body. We then perform a median C2-C3 disectomy followed by creating a gutter in the superior end of C3 body. We then guide the Kirchsner (K) wire purchasing adequate anterior cortex of C2. Rest of the procedure follows the similar steps as described for odontoid screw placement. We achieved 100% correct trajectory and screw placement in our study. There were no instances of screw break out, pull out or nonunion. There was one patient mortality following myocardial infarction in our study. Conclusion: Preoperative imaging details, proper patient positioning, meticulous dissection, thorough anatomical knowledge and few added surgical nuances are the cornerstones in ideal odontoid screw placement. This may be pivotal in managing  patients in developing nations having rudimentary neurosurgical set up. PMID:27990259

  18. Pneumatization of the sphenoid sinus in Chinese: the differences from Caucasian and its application in the extended transsphenoidal approach.

    PubMed

    Lu, Yuntao; Pan, Jun; Qi, Songtao; Shi, Jin; Zhang, Xi'an; Wu, Kuncheng

    2011-08-01

    approach, the use of stricter intraoperative technological devices such as neuronavigation and ultrasound Doppler is advisable.

  19. 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 (CMRO2) 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%, CMRO2 +16%) after resection of the lesions. In perilesional nonedematous tissue only, however, oxygen metabolism (OEF +19%, CMRO2 +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.

  20. Evaluation of Screw Placement Accuracy in Circumferential Lumbar Arthrodesis Using Robotic Assistance and Intraoperative Flat-Panel Computed Tomography.

    PubMed

    Chenin, Louis; Capel, Cyrille; Fichten, Anthony; Peltier, Johann; Lefranc, Michel

    2017-09-01

    Neuronavigation has become a common means of placing pedicle screws in vertebral arthrodesis, because it reduces the incidence of complications related to poor screw positioning. The To evaluate the accuracy of pedicle screw placement during lumbar arthrodesis performed with the new ROSA Spine robot and intraoperative flat-panel computed tomography (fpCT) guidance. We performed a descriptive, observational, retrospective, single-center study of patients having undergone transforaminal lumbar interbody fusion (TLIF) for degenerative pathologies with the ROSA Spine robot and intraoperative fpCT guidance. The primary endpoint was the presence or absence of pedicle wall breach, as assessed from the fpCT scan. Screw placement was graded according to Ravi's classification. Twenty-five patients were operated on between November 2014 and July 2016; 21 underwent minimally invasive TLIF, and 4 underwent open TLIF. The mean ± standard deviation operating time was 241 ± 49.8 minutes. Of the 110 screws placed, 101 (91.8%) were completely within the pedicle (Ravi grade A), 5 (4.5%) had a pedicle wall breach <2 mm (grade B), 2 (1.8%) had a pedicle wall breach of 2-4 mm (grade C), and 2 had pedicle wall breach >4 mm (grade D) (1.8%). One screw (a grade D) was replaced during surgery. None of the breaches were symptomatic. When coupled with fpCT, the ROSA Spine robot is a reliable, accurate means of performing lumbar pedicle screwing. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Internal Maxillary Artery-Middle Cerebral Artery Bypass: Infratemporal Approach for Subcranial-Intracranial (SC-IC) Bypass

    PubMed Central

    Nossek, Erez; Costantino, Peter D.; Eisenberg, Mark; Dehdashti, Amir R.; Setton, Avi; Chalif, David J.; Ortiz, Rafael A.

    2014-01-01

    BACKGROUND: Internal maxillary artery (IMax)–middle cerebral artery (MCA) bypass has been recently described as an alternative to cervical extracranial-intracranial bypass. This technique uses a “keyhole” craniectomy in the temporal fossa that requires a technically challenging end-to-side anastomosis. OBJECTIVE: To describe a lateral subtemporal craniectomy of the middle cranial fossa floor to facilitate wide exposure of the IMax to facilitate bypass. METHODS: Orbitozygomatic osteotomy is used followed by frontotemporal craniotomy and subsequently laterotemporal fossa craniectomy, reaching its medial border at a virtual line connecting the foramen rotundum and foramen ovale. The IMax was identified by using established anatomic landmarks, neuronavigation, and micro Doppler probe (Mizuho Inc. Tokyo, Japan). Additionally, we studied the approach in a cadaveric specimen in preparation for microsurgical bypass. RESULTS: There were 4 cases in which the technique was used. One bypass was performed for flow augmentation in a hypoperfused hemisphere. The other 3 were performed as part of treatment paradigms for giant middle cerebral artery aneurysms. Vein grafts were used in all patients. The proximal anastomosis was performed in an end-to-side fashion in 1 patient and end-to-end in 3 patients. Intraoperative graft flow measured with the Transonic flow probe ranged from 20 to 60 mL/min. Postoperative angiography demonstrated good filling of the graft with robust distal flow in all cases. All patients tolerated the procedure well. CONCLUSION: IMax to middle cerebral artery subcranial-intracranial bypass is safe and efficacious. The laterotemporal fossa craniectomy technique resulted in reliable identification and wide exposure of the IMax, facilitating the proximal anastomosis. ABBREVIATIONS: EC-IC, extracranial-intracranial IMax, internal maxillary artery MCA, middle cerebral artery SC-IC, subcranial-intracranial STA, superficial temporal artery PMID:24618804

  2. Maximizing the petroclival region exposure via a suboccipital retrosigmoid approach: where is the intrapetrous internal carotid artery?

    PubMed

    Colasanti, Roberto; Tailor, Al-Rahim A; Lamki, Tariq; Zhang, Jun; Ammirati, Mario

    2015-06-01

    Recent reports have validated the use of retrosigmoid approach extensions to deal with petroclival lesions. To describe the topographic retrosigmoid anatomy of the intrapetrous internal carotid artery (IICA), providing guidelines for maximizing the petroclival region exposure via this route. The IICA was exposed bilaterally in 6 specimens via a retrosigmoid approach in the semisitting position. Its topographic relationship with pertinent posterolateral cranial base landmarks was quantified with neuronavigation. Safe exposure of the IICA and the surrounding inframeatal/petroclival regions was accomplished in all specimens. On average, the IICA genu was 15.08 mm anterolateral to the XI nerve in the jugular foramen, 16.18 mm anteroinferolateral to the endolymphatic sac, and 10.63 mm anteroinferolateral to the internal acoustic meatus. On average, the IICA horizontal segment was 9.92 mm inferolateral to the Meckel cave, and its midpoint was 19.96 mm anterolateral to the XI nerve in the jugular foramen. The mean distance from the IICA genu to the cochlea was 1.96 mm. The genu and the midpoint of the horizontal segment of the IICA were exposed at a depth of approximately 14.50 mm from the posterior pyramidal wall with the use of different drilling angles (49.74° vs 39.54°, respectively). Knowledge of the IICA general relationship with these landmarks (combined with a careful assessment of the preoperative imaging and with the use of intraoperative navigation and micro-Doppler) may help to enhance the inframeatal/petroclival region exposure via a retrosigmoid route, maximizing safe inframeatal and suprameatal petrous bone removal while minimizing neurovascular complications.

  3. Internal maxillary artery-middle cerebral artery bypass: infratemporal approach for subcranial-intracranial (SC-IC) bypass.

    PubMed

    Nossek, Erez; Costantino, Peter D; Eisenberg, Mark; Dehdashti, Amir R; Setton, Avi; Chalif, David J; Ortiz, Rafael A; Langer, David J

    2014-07-01

    Internal maxillary artery (IMax)-middle cerebral artery (MCA) bypass has been recently described as an alternative to cervical extracranial-intracranial bypass. This technique uses a "keyhole" craniectomy in the temporal fossa that requires a technically challenging end-to-side anastomosis. To describe a lateral subtemporal craniectomy of the middle cranial fossa floor to facilitate wide exposure of the IMax to facilitate bypass. Orbitozygomatic osteotomy is used followed by frontotemporal craniotomy and subsequently laterotemporal fossa craniectomy, reaching its medial border at a virtual line connecting the foramen rotundum and foramen ovale. The IMax was identified by using established anatomic landmarks, neuronavigation, and micro Doppler probe (Mizuho Inc. Tokyo, Japan). Additionally, we studied the approach in a cadaveric specimen in preparation for microsurgical bypass. There were 4 cases in which the technique was used. One bypass was performed for flow augmentation in a hypoperfused hemisphere. The other 3 were performed as part of treatment paradigms for giant middle cerebral artery aneurysms. Vein grafts were used in all patients. The proximal anastomosis was performed in an end-to-side fashion in 1 patient and end-to-end in 3 patients. Intraoperative graft flow measured with the Transonic flow probe ranged from 20 to 60 mL/min. Postoperative angiography demonstrated good filling of the graft with robust distal flow in all cases. All patients tolerated the procedure well. IMax to middle cerebral artery subcranial-intracranial bypass is safe and efficacious. The laterotemporal fossa craniectomy technique resulted in reliable identification and wide exposure of the IMax, facilitating the proximal anastomosis.

  4. 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

  5. Minimally invasive percutaneous screw fixation of traumatic spondylolisthesis of the axis.

    PubMed

    Buchholz, Avery Lee; Morgan, Steven L; Robinson, Leslie C; Frankel, Bruce M

    2015-05-01

    OBJECT Most cases of traumatic spondylolisthesis of the axis (hangman's fracture) can be treated nonoperatively with reduction and subsequent immobilization in a rigid cervical collar or halo. However, in some instances, operative management is necessary and can be accomplished by using either anterior or posterior fusion techniques. Because open posterior procedures can result in significant blood loss, pain, and limited cervical range of motion, other less invasive options for posterior fixation are needed. The authors describe a minimally invasive, navigation-guided technique for surgical treatment of Levine-Edwards (L-E) Type II hangman's fractures. METHODS For 5 patients with L-E Type II hangman's fracture requiring operative reduction and internal fixation, percutaneous screw fixation directed through the fracture site was performed. This technique was facilitated by use of intraoperative 3D fluoroscopy and neuronavigation. RESULTS Of the 5 patients, 2 were women, 3 were men, and age range was 46-67 years. No intraoperative or postoperative complications occurred. All patients wore a rigid cervical collar, and flexion-extension radiographs were obtained at 6 months. For all patients, dynamic imaging demonstrated a stable construct. CONCLUSIONS L-E type II hangman's fractures can be safely repaired by using percutaneous minimally invasive surgical techniques. This technique may be appropriate, depending on circumstances, for all L-E Type I and II hangman's fractures; however, the degree of associated ligament injury and disc disruption must be accounted for. Percutaneous fixation is not appropriate for L-E Type III fractures because of significant displacement and ligament and disc disruption. This report is meant to serve as a feasibility study and is not meant to show superiority of this procedure over other surgical options.

  6. Causal role of the posterior parietal cortex for two-digit mental subtraction and addition: A repetitive TMS study.

    PubMed

    Montefinese, Maria; Turco, Cristina; Piccione, Francesco; Semenza, Carlo

    2017-07-15

    Although parietal areas of the left hemisphere are known to be involved in simple mental calculation, the possible role of the homologue areas of the right hemisphere in mental complex calculation remains debated. In the present study, we tested the causal role of the posterior parietal cortex of both hemispheres in two-digit mental addition and subtraction by means of neuronavigated repetitive TMS (rTMS), investigating possible hemispheric asymmetries in specific parietal areas. In particular, we performed two rTMS experiments, which differed only for the target sites stimulated, on independent samples of participants. rTMS was delivered over the horizontal and ventral portions of the intraparietal sulcus (HIPS and VIPS, respectively) of each hemisphere in Experiment 1, and over the angular and supramarginal gyri (ANG and SMG, respectively) of each hemisphere in Experiment 2. First, we found that each cerebral area of the posterior parietal cortex is involved to some degree in the two-digit addition and subtraction. Second, in Experiment 1, we found a stronger pattern of hemispheric asymmetry for the involvement of HIPS in addition compared to subtraction. In particular, results showed a greater involvement of the right HIPS than the left one for addition. Moreover, we found less asymmetry for the VIPS. Taken together, these results suggest that two-digit mental addition is more strongly associated with the use of a spatial mapping compared to subtraction. In support of this view, in Experiment 2, a greater role of left and right ANG was found for addition needed in verbal processing of numbers and in visuospatial attention processes, respectively. We also revealed a greater involvement of the bilateral SMG in two-digit mental subtraction, in response to greater working memory load required to solve this latter operation compared to addition. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Segregation of Lexical and Sub-Lexical Reading Processes in the Left Perisylvian Cortex

    PubMed Central

    Roux, Franck-Emmanuel; Durand, Jean-Baptiste; Jucla, Mélanie; Réhault, Emilie; Reddy, Marion; Démonet, Jean-François

    2012-01-01

    A fundamental issue in cognitive neuroscience is the existence of two major, sub-lexical and lexical, reading processes and their possible segregation in the left posterior perisylvian cortex. Using cortical electrostimulation mapping, we identified the cortical areas involved on reading either orthographically irregular words (lexical, “direct” process) or pronounceable pseudowords (sublexical, “indirect” process) in 14 right-handed neurosurgical patients while video-recording behavioral effects. Intraoperative neuronavigation system and Montreal Neurological Institute (MNI) stereotactic coordinates were used to identify the localization of stimulation sites. Fifty-one reading interference areas were found that affected either words (14 areas), or pseudo-words (11 areas), or both (26 areas). Forty-one (80%) corresponded to the impairment of the phonological level of reading processes. Reading processes involved discrete, highly localized perisylvian cortical areas with individual variability. MNI coordinates throughout the group exhibited a clear segregation according to the tested reading route; specific pseudo-word reading interferences were concentrated in a restricted inferior and anterior subpart of the left supramarginal gyrus (barycentre x = −68.1; y = −25.9; z = 30.2; Brodmann’s area 40) while specific word reading areas were located almost exclusively alongside the left superior temporal gyrus. Although half of the reading interferences found were nonspecific, the finding of specific lexical or sublexical interferences is new evidence that lexical and sublexical processes of reading could be partially supported by distinct cortical sub-regions despite their anatomical proximity. These data are in line with many brain activation studies that showed that left superior temporal and inferior parietal regions had a crucial role respectively in word and pseudoword reading and were core regions for dyslexia. PMID:23226349

  8. 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.

  9. Simulation of brain tumor resection in image-guided neurosurgery

    NASA Astrophysics Data System (ADS)

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

    2011-03-01

    Preoperative magnetic resonance images are typically used for neuronavigation in image-guided neurosurgery. However, intraoperative brain deformation (e.g., as a result of gravitation, loss of cerebrospinal fluid, retraction, resection, etc.) significantly degrades the accuracy in image guidance, and must be compensated for in order to maintain sufficient accuracy for navigation. Biomechanical finite element models are effective techniques that assimilate intraoperative data and compute whole-brain deformation from which to generate model-updated MR images (uMR) to improve accuracy in intraoperative guidance. To date, most studies have focused on early surgical stages (i.e., after craniotomy and durotomy), whereas simulation of more complex events at later surgical stages has remained to be a challenge using biomechanical models. We have developed a method to simulate partial or complete tumor resection that incorporates intraoperative volumetric ultrasound (US) and stereovision (SV), and the resulting whole-brain deformation was used to generate uMR. The 3D ultrasound and stereovision systems are complimentary to each other because they capture features deeper in the brain beneath the craniotomy and at the exposed cortical surface, respectively. In this paper, we illustrate the application of the proposed method to simulate brain tumor resection at three temporally distinct surgical stages throughout a clinical surgery case using sparse displacement data obtained from both the US and SV systems. We demonstrate that our technique is feasible to produce uMR that agrees well with intraoperative US and SV images after dural opening, after partial tumor resection, and after complete tumor resection. Currently, the computational cost to simulate tumor resection can be up to 30 min because of the need for re-meshing and the trial-and-error approach to refine the amount of tissue resection. However, this approach introduces minimal interruption to the surgical workflow

  10. 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.

  11. Non-invasive Transcranial Magnetic Stimulation (TMS) of the Motor Cortex for Neuropathic Pain—At the Tipping Point?

    PubMed Central

    Treister, Roi; Lang, Magdalena; Klein, Max M.; Oaklander, Anne Louise

    2013-01-01

    The term “neuropathic pain” (NP) refers to chronic pain caused by illnesses or injuries that damage peripheral or central pain-sensing neural pathways to cause them to fire inappropriately and signal pain without cause. Neuropathic pain is common, complicating diabetes, shingles, HIV, and cancer. Medications are often ineffective or cause various adverse effects, so better approaches are needed. Half a century ago, electrical stimulation of specific brain regions (neuromodulation) was demonstrated to relieve refractory NP without distant effects, but the need for surgical electrode implantation limited use of deep brain stimulation. Next, electrodes applied to the dura outside the brain’s surface to stimulate the motor cortex were shown to relieve NP less invasively. Now, electromagnetic induction permits cortical neurons to be stimulated entirely non-invasively using transcranial magnetic stimulation (TMS). Repeated sessions of many TMS pulses (rTMS) can trigger neuronal plasticity to produce long-lasting therapeutic benefit. Repeated TMS already has US and European regulatory approval for treating refractory depression, and multiple small studies report efficacy for neuropathic pain. Recent improvements include “frameless stereotactic” neuronavigation systems, in which patients’ head MRIs allow TMS to be applied to precise underlying cortical targets, minimizing variability between sessions and patients, which may enhance efficacy. Transcranial magnetic stimulation appears poised for the larger trials necessary for regulatory approval of a NP indication. Since few clinicians are familiar with TMS, we review its theoretical basis and historical development, summarize the neuropathic pain trial results, and identify issues to resolve before large-scale clinical trials. PMID:24228166

  12. Motor cortex excitability and connectivity in chronic stroke: a multimodal model of functional reorganization.

    PubMed

    Volz, Lukas J; Sarfeld, Anna-Sophia; Diekhoff, Svenja; Rehme, Anne K; Pool, Eva-Maria; Eickhoff, Simon B; Fink, Gereon R; Grefkes, Christian

    2015-03-01

    Cerebral ischemia triggers a cascade of cellular processes, which induce neuroprotection, inflammation, apoptosis and regeneration. At the neural network level, lesions concomitantly induce cerebral plasticity. Yet, many stroke survivors are left with a permanent motor deficit, and only little is known about the neurobiological factors that determine functional outcome after stroke. Transcranial magnetic stimulation (TMS) and magnetic resonance imaging (MRI) are non-invasive approaches that allow insights into the functional (re-) organization of the cortical motor system. We here combined neuronavigated TMS, MRI and analyses of connectivity to investigate to which degree recovery of hand function depends on corticospinal tract (CST) damage and biomarkers of cerebral plasticity like cortical excitability and motor network effective connectivity. As expected, individual motor performance of 12 stroke patients with persistent motor deficits was found to depend upon the degree of CST damage but also motor cortex excitability and interhemispheric connectivity. In addition, the data revealed a strong correlation between reduced ipsilesional motor cortex excitability and reduced interhemispheric inhibition in severely impaired patients. Interindividual differences in ipsilesional motor cortex excitability were stronger related to the motor deficit than abnormal interhemispheric connectivity or CST damage. Multivariate linear regression analysis combining the three factors accounted for more than 80 % of the variance in functional impairment. The inter-relation of cortical excitability and reduced interhemispheric inhibition provides direct multi-modal evidence for the disinhibition theory of the contralesional hemisphere following stroke. Finally, our data reveal a key mechanism (i.e., the excitability-related reduction in interhemispheric inhibition) accounting for the rehabilitative potential of novel therapeutic approaches which aim at modulating cortical

  13. Cerebellar brain inhibition in the target and surround muscles during voluntary tonic activation.

    PubMed

    Panyakaew, Pattamon; Cho, Hyun Joo; Srivanitchapoom, Prachaya; Popa, Traian; Wu, Tianxia; Hallett, Mark

    2016-04-01

    Motor surround inhibition is the neural mechanism that selectively favours the contraction of target muscles and inhibits nearby muscles to prevent unwanted movements. This inhibition was previously reported at the onset of a movement, but not during a tonic contraction. Cerebellar brain inhibition (CBI) is reduced in active muscles during tonic activation; however, it has not been studied in the surround muscles. CBI was evaluated in the first dorsal interosseus (FDI) muscle as the target muscle, and the abductor digiti minimi, flexor carpi radialis and extensor carpi radialis muscles as surround muscles, during rest and tonic activation of the FDI muscle in 21 subjects. Cerebellar stimulation was performed under magnetic resonance imaging-guided neuronavigation targeting lobule VIII of the cerebellar hemisphere. Stimulus intensities for cerebellar stimulation were based on the resting motor cortex threshold (RMT) and adjusted for the depth difference between the cerebellar and motor cortices. We used 90-120% of the adjusted RMT as the conditioning stimulus intensity during rest. The intensity that generated the best CBI at rest in the FDI muscle was selected for use during tonic activation. During selective tonic activation of the FDI muscle, CBI was significantly reduced only for the FDI muscle, and not for the surround muscles. Unconditioned motor evoked potential sizes were increased in all muscles during FDI muscle tonic activation as compared with rest, despite background electromyography activity increasing only for the FDI muscle. Our study suggests that the cerebellum may play an important role in selective tonic finger movement by reducing its inhibition in the motor cortex only for the relevant agonist muscle.

  14. Multivoxel magnetic resonance spectroscopy identifies enriched foci of cancer stem-like cells in high-grade gliomas

    PubMed Central

    He, Tao; Qiu, Tianming; Wang, Xiaodong; Gui, Hongxing; Wang, Xilong; Hu, Qikuan; Xia, Hechun; Qi, Gaoyang; Wu, Jinsong; Ma, Hui

    2017-01-01

    Objective This study investigated the correlation between choline/creatine (Cho/Cr) ratios determined by multivoxel proton magnetic resonance spectroscopy (1H-MRS) and the distribution of cancer stem-like cells (CSLCs) in high-grade gliomas. Patients and methods Sixteen patients with high-grade gliomas were recruited and underwent 1H-MRS examination before surgery to identify distinct tumor regions with variable Cho/Cr ratios. Using intraoperative neuronavigation, tumor tissues were accurately sampled from regions with high and low Cho/Cr ratios within each tumor. The distribution of CSLCs in samples from glioma tissue regions with different Cho/Cr ratios was quantified by neurosphere culture, immunohistochemistry, and Western blot. Results The mean neurosphere formation rate in tissues with high Cho/Cr ratios was significantly increased compared with that in low Cho/Cr ratio tissues (13.94±5.94 per 100 cells vs 8.04±3.99 per 100 cells, P<0.001). Immunohistochemistry indicated that tissues with high Cho/Cr ratios had elevated expression of CD133, nestin, and CD15, relative to low Cho/Cr ratio tissue samples (23.6%±3.8% vs 18.3%±3.3%, 25.2%±4.5% vs 19.8%±2.8%, 24.5%±3.8% vs 17.8%±2.2%, respectively; all P<0.001). Western blot demonstrated that relative CD133 and nestin protein expression in high Cho/Cr ratio regions was significantly higher than that in low Cho/Cr ratio tissue samples (0.50±0.17 vs 0.30±0.08, 0.45±0.13 vs 0.27±0.07, respectively; both P<0.001). The protein expression levels of CD133 and nestin were highly correlated with Cho/Cr ratios (r=0.897 and r=0.861, respectively). Conclusion Cho/Cr ratios correlate with the distribution of CSLCs in high-grade gliomas, and this may assist in identifying foci enriched with CSLCs and thus improve the management of high-grade gliomas. PMID:28115854

  15. Probabilistic versus deterministic tractography for delineation of the cortico-subthalamic hyperdirect pathway in patients with Parkinson disease selected for deep brain stimulation.

    PubMed

    Petersen, Mikkel V; Lund, Torben E; Sunde, Niels; Frandsen, Jesper; Rosendal, Frederikke; Juul, Niels; Østergaard, Karen

    2017-05-01

    tensor-based method, which demonstrated a 1.9-2.4 times higher variation. CONCLUSIONS These data provide a strong impetus for the use of a robust probabilistic tractography framework based on constrained spherical deconvolution, or similar advanced DWI models, in clinical settings. The inherent limitations and demonstrated inaccuracy of the tensor-based method leave it questionable for use in high-precision stereotactic DBS surgery. The authors have also described a straightforward method for importing tractography-derived information into any clinical neuronavigation system, based on the generation of track-density images.

  16. Biopsy versus resection for the management of low-grade gliomas.

    PubMed

    Veeravagu, Anand; Jiang, Bowen; Ludwig, Cassie; Chang, Steven D; Black, Keith L; Patil, Chirag G

    2013-04-30

    resection. One study was a population-based parallel cohort and not an RCT. Four studies were RCTs, however patients were randomized with respect to varying radiotherapy regimens to assess timing and dose of radiation. One RCT was focused on high-grade gliomas and not LGG. One last RCT evaluated diffusion tensor imaging (DTI)-based neuro-navigation for surgical resection. Currently there are no randomized clinical trials or controlled clinical trials available on which to base clinical decisions. Therefore, physicians must approach each case individually and weigh the risks and benefits of each intervention until further evidence is available. Future research could focus on randomized clinical trials to determine outcomes benefits for biopsy versus resection.

  17. FMRI Effective Connectivity and TMS Chronometry: Complementary Accounts of Causality in the Visuospatial Judgment Network

    PubMed Central

    de Graaf, Tom A.; Jacobs, Christianne; Roebroeck, Alard; Sack, Alexander T.

    2009-01-01

    Background While traditionally quite distinct, functional neuroimaging (e.g. functional magnetic resonance imaging: fMRI) and functional interference techniques (e.g. transcranial magnetic stimulation: TMS) increasingly address similar questions of functional brain organization, including connectivity, interactions, and causality in the brain. Time-resolved TMS over multiple brain network nodes can elucidate the relative timings of functional relevance for behavior (“TMS chronometry”), while fMRI functional or effective connectivity (fMRI EC) can map task-specific interactions between brain regions based on the interrelation of measured signals. The current study empirically assessed the relation between these different methods. Methodology/Principal Findings One group of 15 participants took part in two experiments: one fMRI EC study, and one TMS chronometry study, both of which used an established cognitive paradigm involving one visuospatial judgment task and one color judgment control task. Granger causality mapping (GCM), a data-driven variant of fMRI EC analysis, revealed a frontal-to-parietal flow of information, from inferior/middle frontal gyrus (MFG) to posterior parietal cortex (PPC). FMRI EC-guided Neuronavigated TMS had behavioral effects when applied to both PPC and to MFG, but the temporal pattern of these effects was similar for both stimulation sites. At first glance, this would seem in contradiction to the fMRI EC results. However, we discuss how TMS chronometry and fMRI EC are conceptually different and show how they can be complementary and mutually constraining, rather than contradictory, on the basis of our data. Conclusions/Significance The findings that fMRI EC could successfully localize functionally relevant TMS target regions on the single subject level, and conversely, that TMS confirmed an fMRI EC identified functional network to be behaviorally relevant, have important methodological and theoretical implications. Our results, in

  18. Intraoperative computed tomography for intracranial electrode implantation surgery in medically refractory epilepsy.

    PubMed

    Lee, Darrin J; Zwienenberg-Lee, Marike; Seyal, Masud; Shahlaie, Kiarash

    2015-03-01

    Accurate placement of intracranial depth and subdural electrodes is important in evaluating patients with medically refractory epilepsy for possible resection. Confirming electrode locations on postoperative CT scans does not allow for immediate replacement of malpositioned electrodes, and thus revision surgery is required in select cases. Intraoperative CT (iCT) using the Medtronic O-arm device has been performed to detect electrode locations in deep brain stimulation surgery, but its application in epilepsy surgery has not been explored. In the present study, the authors describe their institutional experience in using the O-arm to facilitate accurate placement of intracranial electrodes for epilepsy monitoring. In this retrospective study, the authors evaluated consecutive patients who had undergone subdural and/or depth electrode implantation for epilepsy monitoring between November 2010 and September 2012. The O-arm device is used to obtain iCT images, which are then merged with the preoperative planning MRI studies and reviewed by the surgical team to confirm final positioning. Minor modifications in patient positioning and operative field preparation are necessary to safely incorporate the O-arm device into routine intracranial electrode implantation surgery. The device does not obstruct surgeon access for bur hole or craniotomy surgery. Depth and subdural electrode locations are easily identified on iCT, which merge with MRI studies without difficulty, allowing the epilepsy surgical team to intraoperatively confirm lead locations. Depth and subdural electrodes were implanted in 10 consecutive patients by using routine surgical techniques together with preoperative stereotactic planning and intraoperative neuronavigation. No wound infections or other surgical complications occurred. In one patient, the hippocampal depth electrode was believed to be in a suboptimal position and was repositioned before final wound closure. Additionally, 4 strip electrodes were

  19. Initial experience with endoscopic ultrasonic aspirator in purely neuroendoscopic removal of intraventricular tumors.

    PubMed

    Cinalli, Giuseppe; Imperato, Alessia; Mirone, Giuseppe; Di Martino, Giuliana; Nicosia, Giancarlo; Ruggiero, Claudio; Aliberti, Ferdinando; Spennato, Pietro

    2017-03-01

    OBJECTIVE Neuroendoscopic removal of intraventricular tumors is difficult and time consuming because of the lack of an effective decompression system that can be used through the working channel of the endoscope. The authors report on the utilization of an endoscopic ultrasonic aspirator in the resection of intraventricular tumors. METHODS Twelve pediatric patients (10 male, 2 female), ages 1-15 years old, underwent surgery via a purely endoscopic approach using a Gaab rigid endoscope and endoscopic ultrasonic aspirator. Two patients presented with intraventricular metastases from high-grade tumors (medulloblastoma, atypical teratoid rhabdoid tumor), 2 with subependymal giant cell astrocytomas (associated with tuberous sclerosis), 2 with low-grade intraparaventricular tumors, 4 with suprasellar tumors (2 craniopharyngiomas and 2 optic pathway gliomas), and 2 with pineal tumors (1 immature teratoma, 1 pineal anlage tumor). Hydrocephalus was present in 5 cases. In all patients, the endoscopic trajectory and ventricular access were guided by electromagnetic neuronavigation. Nine patients underwent surgery via a precoronal bur hole while supine. In 2 cases, surgery was performed through a frontal bur hole at the level of the hairline. One patient underwent surgery via a posterior parietal approach to the trigone while in a lateral position. The endoscopic technique consisted of visualization of the tumor, ventricular washing to dilate the ventricles and to control bleeding, obtaining a tumor specimen with biopsy forceps, and ultrasonic aspiration of the tumor. Bleeding was controlled with irrigation, monopolar coagulation, and a thulium laser. RESULTS In 7 cases, the resection was total or near total (more than 90% of lesion removed). In 5 cases, the resection was partial. Histological evaluation of the collected material (withdrawn using biopsy forceps and aspirated with an ultrasonic aspirator) was diagnostic in all cases. The duration of surgery ranged from 30 to

  20. Study of the biodistribution of fluorescein in glioma-infiltrated mouse brain and histopathological correlation of intraoperative findings in high-grade gliomas resected under fluorescein fluorescence guidance.

    PubMed

    Diaz, Roberto Jose; Dios, Roberto Rey; Hattab, Eyas M; Burrell, Kelly; Rakopoulos, Patricia; Sabha, Nesrin; Hawkins, Cynthia; Zadeh, Gelareh; Rutka, James T; Cohen-Gadol, Aaron A

    2015-06-01

    fluorescence was highly specific (up to 90.9%) while its sensitivity was 82.2%. False negatives occurred due to lack of fluorescence in areas of diffuse, low-density cellular infiltration. Margins of contrast enhancement based on intraoperative MRI-guided StealthStation neuronavigation correlated well with fluorescent tumor margins. GTR of the contrast-enhancing area as guided by the fluorescent signal was achieved in 100% of cases based on postoperative MRI. Fluorescein sodium does not appear to selectively accumulate in astrocytoma cells but in extracellular tumor cell-rich locations, suggesting that fluorescein is a marker for areas of compromised blood-brain barrier within high-grade astrocytoma. Fluorescein fluorescence appears to correlate intraoperatively with the areas of MR enhancement, thus representing a practical tool to help the surgeon achieve GTR of the enhancing tumor regions.

  1. 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

  2. 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.

  3. Intracerebroventricular Pain Treatment with Analgesic Mixtures including Ziconotide for Intractable Pain.

    PubMed

    Staquet, Héléne; Dupoiron, Denis; Nader, Edmond; Menei, Philippe

    2016-07-01

    Intracerebroventricular (ICV) administration of opioids for control of intractable cancer pain has been used since 1982. We present here our experience of intracerebroventricular administration of pain treatments including ziconotide associated with morphine and ropivacaine for patients resistant to a conventional approach, with nociceptive, neuropathic, or mixed pain. These clinical cases were conducted with patients suffering from refractory pain, more than 6/10 on a numerical pain rating scale (NPRS) while on high-dose medical treatment and/or intolerance with significant side effects from oral medication. The baseline study visit included a physical examination and an assessment of pain intensity on a NPRS. Under general anesthesia, a neuronavigation device was used to place the catheter on the floor of the third ventricle, supported by an endoscope. Then, drugs were injected in the cerebroventricular system, through a pump (external or subcutaneous). The primary objective was to measure pain evaluation with ICV treatment after a complete withdrawal of other medications.Four patients were enrolled: 3 with intractable cancer pain and one with central neuropathic pain. The median NPRS at baseline was 9.5 [8.5; 19]. The mean NPRS after one month was 3.5 [3; 4.5]. Ziconotide was initiated at 0.48 µg/d and up to a median of 1.2 µg/d [1.0; 1.56]. The median dose of morphine and ropivacaine used initially was respectively 0.36 mg/d [0.24; 0.66] up to 0.6 mg/d [0.45; 4.63] and 1.2 mg/d [0; 2.4] up to 2.23 mg/d [1.2; 3.35]. Minor side effects were initially observed but transiently. One psychiatric agitation required discontinuation of ziconotide infusion. For intractable pain, using ziconotide by intracerebroventricular infusion seems safe and efficient, specifically for chronic neoplastic pain of cervicocephalic, thoracic, or diffuse origin and also for pain arising from a central neuropathic mechanism.

  4. Functional MRI-navigated repetitive transcranial magnetic stimulation over supplementary motor area in chronic tic disorders.

    PubMed

    Wu, Steve W; Maloney, Thomas; Gilbert, Donald L; Dixon, Stephan G; Horn, Paul S; Huddleston, David A; Eaton, Kenneth; Vannest, Jennifer

    2014-01-01

    Open label studies have shown repetitive transcranial magnetic stimulation to be effective in reducing tics. To determine whether 8 sessions of continuous theta burst stimulation (cTBS) over supplementary motor area (SMA) given over 2 days may reduce tics and motor cortical network activity in Tourette syndrome/chronic tic disorders. This was a randomized (1:1), double-blind, sham-controlled trial of functional MRI (fMRI)-navigated, 30 Hz cTBS at 90% of resting motor threshold (RMT) over SMA in 12 patients ages 10-22 years. Comorbid ADHD (n = 8), OCD (n = 8), and stable concurrent medications (n = 9) were permitted. Neuro-navigation utilized each individual's event-related fMRI signal. Primary clinical and cortical outcomes were: 1) Yale Global Tic Severity Scale (YGTSS) at one week; 2) fMRI event-related signal in SMA and primary motor cortex (M1) during a finger-tapping motor task. Baseline characteristics were not statistically different between groups (age, current tic/OCD/ADHD severities, tic-years, number of prior medication trials, RMT). Mean YGTSS scores decreased in both active (27.5 ± 7.4 to 23.2 ± 9.8) and sham (26.8 ± 4.8 to 21.7 ± 7.7) groups. However, no significant difference in video-based tic severity rating was detected between the two groups. Two-day post-treatment fMRI activation during finger tapping decreased significantly in active vs. sham groups for SMA (P = 0.02), left M1 (P = 0.0004), and right M1 (P < 0.0001). No serious adverse events occurred. Active, fMRI-navigated cTBS administered in 8 sessions over 2 days to the SMA induced significant inhibition in the motor network (SMA, bilateral M1). However, both groups on average experienced tic reduction at 7 days. Larger sample size and protocol modifications may be needed to produce clinically significant tic reduction beyond placebo effect. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. 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

  6. High-sensitivity TMS/fMRI of the Human Motor Cortex Using a Dedicated Multichannel MR Coil.

    PubMed

    Navarro de Lara, Lucia I; Tik, Martin; Woletz, Michael; Frass-Kriegl, Roberta; Moser, Ewald; Laistler, Elmar; Windischberger, Christian

    2017-04-15

    To validate a novel setup for concurrent TMS/fMRI in the human motor cortex based on a dedicated, ultra-thin, multichannel receive MR coil positioned between scalp and TMS system providing greatly enhanced sensitivity compared to the standard birdcage coil setting. A combined TMS/fMRI design was applied over the primary motor cortex based on 1Hz stimulation with stimulation levels of 80%, 90%, 100%, and 110% of the individual active motor threshold, respectively. Due to the use of a multichannel receive coil we were able to use multiband-accelerated (MB=2) EPI sequences for the acquisition of functional images. Data were analysed with SPM12 and BOLD-weighted signal intensity time courses were extracted in each subject from two local maxima (individual functional finger tapping localiser, fixed MNI coordinate of the hand knob) next to the hand area of the primary motor cortex (M1) and from the global maximum. We report excellent image quality without noticeable signal dropouts or image distortions. Parameter estimates in the three peak voxels showed monotonically ascending activation levels over increasing stimulation intensities. Across all subjects, mean BOLD signal changes for 80%, 90%, 100%, 110% of the individual active motor threshold were 0.43%, 0.63%, 1.01%, 2.01% next to the individual functional finger tapping maximum, 0.73%, 0.91%, 1.34%, 2.21% next to the MNI-defined hand knob and 0.88%, 1.09%, 1.65%, 2.77% for the global maximum, respectively. Our results show that the new setup for concurrent TMS/fMRI experiments using a dedicated MR coil array allows for high-sensitivity fMRI particularly at the site of stimulation. Contrary to the standard birdcage approach, the results also demonstrate that the new coil can be successfully used for multiband-accelerated EPI acquisition. The gain in flexibility due to the new coil can be easily combined with neuronavigation within the MR scanner to allow for accurate targeting in TMS/fMRI experiments. Copyright

  7. Transsphenoidal Resection of Sellar Tumors Using High-Field Intraoperative Magnetic Resonance Imaging

    PubMed Central

    Szerlip, Nicholas J.; Zhang, Yi-Chen; Placantonakis, Dimitris G.; Goldman, Marc; Colevas, Kara B.; Rubin, David G.; Kobylarz, Eric J.; Karimi, Sasan; Girotra, Monica; Tabar, Viviane

    2011-01-01

    There has been increasing experience in the utilization of intraoperative magnetic resonance imaging (iMRI) for intracranial surgery. Despite this trend, only a few U.S centers have examined the use of this technology for transsphenoidal resection of tumors of the sella. We present the largest series in North America examining the role of iMRI for pituitary adenoma resection. We retrospectively reviewed our institutional experience of 59-patients who underwent transsphenoidal procedures for sellar and suprasellar tumors with iMRI guidance. Of these, 52 patients had a histological diagnosis of pituitary adenoma. The technical results of this subgroup were examined. A 1.5-T iMRI was integrated with the BrainLAB (Feldkirchen, Germany) neuronavigation system. The majority (94%) of tumors in our series were macroadenomas. Seventeen percent of tumors were confined to the sella, 49% had suprasellar extensions without involvement of the cavernous sinus, 34% had frank cavernous sinus invasion. All patients underwent at least one iMRI, and 19% required one or more additional sets of intraoperative imaging. In 58% of patients, iMRI led to the surgeon attempting more resection. A gross total resection was obtained in 67% of the patients with planned total resections. There was one case of permanent postoperative diabetes insipidus and no other instances of new hormone replacement. In summary, iMRI was most useful for tumors of the sella with and without suprasellar extension where the information from the iMRI extended the complete resection rate from 40 to 72% and 55 to 88%, respectively. As one would expect, it did not substantially increase the rate of resection of tumors with cavernous sinus invasion. Overall, iMRI was particularly useful in guiding resection safely, aiding in clinical decision making, and allowing identification and preservation of the pituitary stalk and normal pituitary gland. Limitations of the iMRI include a need for additional personnel and training

  8. 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

  9. Preoperative correlation of intraoperative cortical mapping with magnetic resonance imaging landmarks to predict localization of the Broca area.

    PubMed

    Quiñones-Hinojosa, Alfredo; Ojemann, Steven G; Sanai, Nader; Dillon, William P; Berger, Mitchel S

    2003-08-01

    Broca identified the posterior third of the inferior frontal gyrus as a locus essential for the production of fluent speech. The authors have conducted this retrospective analysis in an attempt to find readily identifiable landmarks on magnetic resonance (MR) imaging that correspond to intraoperative cortical stimulation-induced speech arrest. These landmarks demonstrate novel structural-functional relationships that can be used preoperatively to predict the location of the Broca area. Using a neuronavigation system, sites where stimulation produced speech arrest (Broca area) were recorded in a consecutive series of patients undergoing awake tumor resections in the perisylvian territory of the dominant hemisphere. The authors reviewed 33 consecutive patients by projecting the MR imaging data sets and marking the site where the Broca area was identified. Sulcus topography was analyzed with respect to this site by scrolling into neighboring planes and classifying the frontal operculum into one of the four schemes of sulcus variability described by Ebeling, et al. The following categories of frontal opercula were found: 18 (69%) of 26 were Type I, eight (31%) of 26 were Type III, and seven cases eluded classification because of sulcal effacement. For patients with Type I anatomy, the Broca area was adjacent to, and distributed evenly around, the inferior precentral sulcus (IPS). Quantitatively, the site of speech arrest was located a mean of 2.4 +/- 0.25 cm from the anteroinferior aspect of the pars opercularis, where it abuts the subarachnoid space surrounding the apex of the pars triangularis. For all patients with Type III anatomy, the Broca area was adjacent to the accessory sulcus that lies immediately posterior to the IPS. In these patients the mean distance from the anterior inferior pars opercularis was 2.3 +/- 0.29 cm. The mean distance from the Broca area to the edge of the tumor for the 26 patients with clear sulcal anatomy was 1.29 +/- 0.12 cm. The results

  10. The value of 3D-FIESTA MRI in detecting non-iatrogenic cerebrospinal fluid rhinorrhoea: correlations with endoscopic endonasal surgery.

    PubMed

    Xie, Tao; Sun, Wei; Zhang, Xiaobiao; Liu, Tengfei; Ding, Hailing; Hu, Fan; Yu, Yong; Gu, Ye

    2016-12-01

    In this study, we investigated the value of three-dimensional (3D) fast-imaging employing steady-state acquisition (FIESTA) magnetic resonance imaging (MRI) in detecting non-iatrogenic cerebrospinal fluid (CSF) rhinorrhoea and compared it with regular MRI and 3D magnetisation prepared rapid acquisition gradient echo (MPRAGE) MRI sequences, as well as high-resolution computed tomography (HRCT) imaging. We also present the endoscopic experiences of such cases. From June 2011 to Feb 2016, 17 patients with non-iatrogenic cerebrospinal fluid rhinorrhoea were included. Seven patients had spontaneous rhinorrhoea, three patients had invasive tumours, and the remaining patients had traumatic aetiologies. All the patients underwent HRCT, regular MRI sequence imaging, 3D-MPRAGE MRI sequence imaging and 3D-FIESTA MRI sequence imaging for the preoperative evaluations of the leakages. For each patient, the CSF fistula site was confirmed by intraoperative neuronavigation and endoscopic findings. Statistical analyses were performed. All patients underwent endoscopic multilayer repair. The sensitivities of the HRCT, regular MRI (T1 and T2), 3D-MPRAGE and 3D-FIESTA modalities for identifying CSF leakage were 58.8 %, (11.8 % and 29.4 %), 74.7 %, and 88.2 %, respectively. The origins of the leakages included the cribriform plate (18 %), ethmoidal fovea (23 %), lateral recess of the sphenoid (17 %), sellar floor (12 %), ethmoidal roof (12 %), junction of the fovea and cribriform plate (6 %) and the junction of sellar and sphenoidal planum (6 %). Two patients required repair. The first was under local anaesthesia when the nasal packing was removed, and the second underwent repair at the same site a half-year later due to hydrocephalus. Lumbar drainage was performed in all cases. No major complications were encountered. The endoscopic endonasal approach is safe and effective for the treatment of CSF rhinorrhoea. The 3D-FIESTA MR modality is superior to 3D-MPRAGE MR and HRCT

  11. NI-18MULTIMODAL NAVIGATION IN ENDOSCOPIC TRANS-SPHENOIDAL RESECTION OF PITUITARY TUMORS USING IMAGE-BASED VASCULAR AND CRANIAL NERVE SEGMENTATION: A PROSPECTIVE VALIDATION STUDY

    PubMed Central

    Dolati, Parviz; Raber, Michael; Golby, Alexandra; Laws, Edward

    2014-01-01

    Trans-Sphenoidal surgery (TSS) is a well-known approach for treatment of pituitary tumors. However, in inexperienced hands, the risk of lateral misdirection and vascular damage, intraoperative CSF leakage, and optic nerve injury are all well-known complications of this procedure. This prospective study was conducted to validate the accuracy of image-based segmentation in localization of neurovascular structures during TSS. METHODS: Eight patients with pituitary tumor 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 (6/8) and Stryker (2/8) for segmentation and pre-op planning. After patient registration to the intra-op neuronavigation system and surgical exposure, each segmented neural or vascular element was validated by manual placement of the navigation probe. The pulses of the bilateral ICA were confirmed using micro-Doppler. RESULTS: Pre-operative segmentation of the ICA and cavernous sinus matched with the intra-operative endoscopic and micro-Doppler findings in all cases (Dice-coefficient =1). This information reassured surgeons regarding the lateral extent of bone removal at the sellar floor and the limits of lateral explorations. Perfect correspondence between image-based segmentation and endoscopic view was also found at the surface of the tumor and tumor-normal gland interfaces. This helped in preventing unnecessary removal of the normal pituitary gland. Image-guidance helped surgeon to localize the optic nerve and chiasm in 63% of case and Diaphragma sella in 50% of cases, which helped to determine the limits of upward exploration and decrease the risk of CSF leakage. CONCLUSION: Image-based pre-operative vascular and neural element segmentation especially with 3D reconstruction is highly informative preoperatively and helps young and inexperienced neurosurgeons to prevent

  12. (68)Ga-Pentixafor-PET/CT for Imaging of Chemokine Receptor 4 Expression in Glioblastoma.

    PubMed

    Lapa, Constantin; Lückerath, Katharina; Kleinlein, Irene; Monoranu, Camelia Maria; Linsenmann, Thomas; Kessler, Almuth F; Rudelius, Martina; Kropf, Saskia; Buck, Andreas K; Ernestus, Ralf-Ingo; Wester, Hans-Jürgen; Löhr, Mario; Herrmann, Ken

    2016-01-01

    Chemokine receptor-4 (CXCR4) has been reported to be overexpressed in glioblastoma (GBM) and to be associated with poor survival. This study investigated the feasibility of non-invasive CXCR4-directed imaging with positron emission tomography/computed tomography (PET/CT) using the radiolabelled chemokine receptor ligand (68)Ga-Pentixafor. 15 patients with clinical suspicion on primary or recurrent glioblastoma (13 primary, 2 recurrent tumors) underwent (68)Ga-Pentixafor-PET/CT for assessment of CXCR4 expression prior to surgery. O-(2-(18)F-fluoroethyl)-L-tyrosine ((18)F-FET) PET/CT images were available in 11/15 cases and were compared visually and semi-quantitatively (SUVmax, SUVmean). Tumor-to-background ratios (TBR) were calculated for both PET probes. (68)Ga-Pentixafor-PET/CT results were also compared to histological CXCR4 expression on neuronavigated surgical samples. (68)Ga-Pentixafor-PET/CT was visually positive in 13/15 cases with SUVmean and SUVmax of 3.0±1.5 and 3.9±2.0 respectively. Respective values for (18)F-FET were 4.4±2.0 (SUVmean) and 5.3±2.3 (SUVmax). TBR for SUVmean and SUVmax were higher for (68)Ga-Pentixafor than for (18)F-FET (SUVmean 154.0±90.7 vs. 4.1±1.3; SUVmax 70.3±44.0 and 3.8±1.2, p<0.01), respectively. Histological analysis confirmed CXCR4 expression in tumor areas with high (68)Ga-Pentixafor uptake; regions of the same tumor without apparent (68)Ga-Pentixafor uptake showed no or low receptor expression. In this pilot study, (68)Ga-Pentixafor retention has been observed in the vast majority of glioblastoma lesions and served as readout for non-invasive determination of CXCR4 expression. Given the paramount importance of the CXCR4/SDF-1 axis in tumor biology, (68)Ga-Pentixafor-PET/CT might prove a useful tool for sensitive, non-invasive in-vivo quantification of CXCR4 as well as selection of patients who might benefit from CXCR4-directed therapy.

  13. Image guidance based on MRI for spinal interstitial laser thermotherapy: technical aspects and accuracy.

    PubMed

    Tatsui, Claudio E; Nascimento, Clarissa N G; Suki, Dima; Amini, Behrang; Li, Jing; Ghia, Amol J; Thomas, Jonathan G; Stafford, R Jason; Rhines, Laurence D; Cata, Juan P; Kumar, Ashok J; Rao, Ganesh

    2017-02-10

    OBJECTIVE Image guidance for spinal procedures is based on 3D-fluoroscopy or CT, which provide poor visualization of soft tissues, including the spinal cord. To overcome this limitation, the authors developed a method to register intraoperative MRI (iMRI) of the spine into a neuronavigation system, allowing excellent visualization of the spinal cord. This novel technique improved the accuracy in the deployment of laser interstitial thermal therapy probes for the treatment of metastatic spinal cord compression. METHODS Patients were positioned prone on the MRI table under general anesthesia. Fiducial markers were applied on the skin of the back, and a plastic cradle was used to support the MRI coil. T2-weighted MRI sequences of the region of interest were exported to a standard navigation system. A reference array was sutured to the skin, and surface matching of the fiducial markers was performed. A navigated Jamshidi needle was advanced until contact was made with the dorsal elements; its position was confirmed with intraoperative fluoroscopy prior to advancement into a target in the epidural space. A screenshot of its final position was saved, and then the Jamshidi needle was exchanged for an MRI-compatible access cannula. MRI of the exact axial plane of each access cannula was obtained and compared with the corresponding screenshot saved during positioning. The discrepancy in millimeters between the trajectories was measured to evaluate accuracy of the image guidance RESULTS Thirteen individuals underwent implantation of 47 laser probes. The median absolute value of the discrepancy between the location predicted by the navigation system and the actual position of the access cannulas was 0.7 mm (range 0-3.2 mm). No injury or adverse event occurred during the procedures. CONCLUSIONS This study demonstrates the feasibility of image guidance based on MRI to perform laser interstitial thermotherapy of spinal metastasis. The authors' method permits excellent

  14. P12.09MALIGNANT TUMORS OF ANTERIOR SKULL BASE: IS THE ROLE OF SURGERY ENHANCED IN THE ENDOSCOPY ERA?

    PubMed Central

    Nasi, D.; Iacoangeli, M.; Dallari, S.; Salvinelli, F.; Dobran, M.; di Somma, L.; Colasanti, R.; Nocchi, N.; Vaira, C.; Scerrati, M.

    2014-01-01

    INTRODUCTION: Malignant tumors of anterior skull base represent a surgical challenge because of their anatomical location, the necessity of achieving negative margins, and the often-cosmetically disfiguring transfacial approaches needed. Recently, expanded endonasal endoscopic approaches (EEEA) have been developed, either alone or combined with transcranial approaches for treatment of these malignant lesions. We report our experience to illustrate the relative safety and effectiveness of the EEEA for skull base malignancies alone or combined when possible with minimally invasive approaches or traditional surgery. METHODS: From June 2009, 13 patients harbouring malignant neoplastic lesions of anterior skull base were treated at our department. Four patients affected by sinonasal malignancies with extension in anterior cranial fossa underwent to combined open subfrontal or minimally invasive supra orbital approach and EEEA. In 2 patients with respectively esthesioneuroblastoma and maxillary sinus squamous cell carcinoma a combined supraorbital key-hole craniotomy and EEEA were perfomed. Seven clival metastases with VI cranial nerve palsy were approached by the EEEA supplemented by neuronavigation. RESULTS: Gross total removal was performed in 9 out of 13 patients. In the other cases partial resection, but with adequate decompression and diagnosis were achieved. There were no mortality, 1 patient had infection and 1 deep vein thrombosis. CONCLUSIONS: In our experience EEEA are an integral part of the neurosurgical armamentarium for the treatment of the skull base malignancies. In properly selected cases, it affords similar oncologic outcomes with lower morbidity than traditional open approaches. The major potential advantage of the EEEA approach is direct “natural” anatomical route to the lesion without traversing any major neurovascular structures, so obviating brain retraction. Many tumors grow in a medial-to-lateral direction, displacing structures laterally as

  15. P13.10SURGICAL TREATMENT FOR GLIOBLASTOMA MULTIFORME: OUTCOME AND ANALYSIS OF PROGNOSTIC FACTORS ESPECIALLY ORIENTED TO THE EXTENT OF SURGICAL RESECTION

    PubMed Central

    Di Somma, L.; Iacoangeli, M.; Alvaro, L.; Di Rienzo, A.; Liverotti, V.; Della Costanza, M.; Brunozzi, D.; Polonara, G.; Scarpelli, M.; Scerrati, M.

    2014-01-01

    INTRODUCTION: The prognosis of Glioblastoma Multiforme (GBM) remains poor despite recent therapeutic advances. The surgical treatment of GBM (supported by functional imaging, neuronavigation and electrophysiological monitoring) remains a fundamental step. The methylation of the enzyme O6-methylguanine-DNA methyltransefrase (MGMT) seems to improve the effectiveness of alkylating agents on this tumour, but other factors can influence the survival. An evaluation of all prognostic factors is essential to individuate subgroups of patients for a better selection of different treatment modalities. Our study confirms the prognostic values of both new recognized factors (MGMT presence, IDH1, news schedule of TM2 etc.) and the well-recognized prognostic factors particularly to the extent of surgical removal with the help of new technologies and in the era where people is asking more and more a better quality of life. METHODS: We retrospectively analysed 172 operated patients (115 males and 57 females), 55 of which located in eloquent areas, between March 2008 and December 2012. For each patient age, sex, preoperative clinical evaluation (Karnofsky score, KPS), tumour location, extent of surgical removal, genetic and epigenetic profile (MGMT, IDH1,etc) and postoperative treatments were recorded. We used Kaplan Meier method for the univariate analysis and the Cox regression for the multivariate one. Surgical strategy was always planned for a total tumour resection, when allowed by the intrinsic characteristics of the tumour using the so called “extracapsular “ technique. RESULTS: Overall median survival time after surgery was 10 months. At univariate analysis the gross total removal (p<0,0001), a postoperative KPS>70 (p<0,0001) and radiotherapy (p<0,0001) improve survivals. Deep structures involved or multifocal lesions (p<0,0001) resulted as negative factors in term of the quod vitam prognosis, whereas lesions arising in insula, deep structures or in primary motor cortex

  16. 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

  17. Application of contrast-enhanced T1-weighted MRI-based 3D reconstruction of the dural tail sign in meningioma resection.

    PubMed

    You, Binsheng; Cheng, Yanhao; Zhang, Jian; Song, Qimin; Dai, Chao; Heng, Xueyuan; Fei, Chang

    2016-07-01

    OBJECT The goal of this study was to investigate the significance of contrast-enhanced T1-weighted (T1W) MRI-based 3D reconstruction of dural tail sign (DTS) in meningioma resection. METHODS Between May 2013 and August 2014, 18 cases of convexity and parasagittal meningiomas showing DTS on contrast-enhanced T1W MRI were selected. Contrast-enhanced T1W MRI-based 3D reconstruction of DTS was conducted before surgical treatment. The vertical and anteroposterior diameters of DTS on the contrast-enhanced T1W MR images and 3D reconstruction images were measured and compared. Surgical incisions were designed by referring to the 3D reconstruction and MR images, and then the efficiency of the 2 methods was evaluated with assistance of neuronavigation. RESULTS Three-dimensional reconstruction of DTS can reveal its overall picture. In most cases, the DTS around the tumor is uneven, whereas the DTS around the dural vessels presents longer extensions. There was no significant difference (p > 0.05) between the vertical and anteroposterior diameters of DTS measured on the contrast-enhanced T1W MR and 3D reconstruction images. The 3D images of DTS were more intuitive, and the overall picture of DTS could be revealed in 1 image, which made it easier to design the incision than by using the MR images. Meanwhile, assessment showed that the incisions designed using 3D images were more accurate than those designed using MR images (ridit analysis by SAS, F = 7.95; p = 0.008). Pathological examination showed that 34 dural specimens (except 2 specimens from 1 tumor) displayed tumor invasion. The distance of tumor cell invasion was 1.0-21.6 mm (5.4 ± 4.41 mm [mean ± SD]). Tumor cell invasion was not observed at the dural resection margin in all 36 specimens. CONCLUSIONS Contrast-enhanced T1W MRI-based 3D reconstruction can intuitively and accurately reveal the size and shape of DTS, and thus provides guidance for designing meningioma incisions.

  18. Biopsy versus resection for the management of low-grade gliomas.

    PubMed

    Jiang, Bowen; Chaichana, Kaisorn; Veeravagu, Anand; Chang, Steven D; Black, Keith L; Patil, Chirag G

    2017-04-27

    updated citations were searched and critically analyzed for relevance. This was undertaken independently by two review authors. The original electronic database searches yielded a total of 2764 citations. In total, 4139 citations have been critically analyzed for this updated review. No new RCTs of biopsy or resection for LGG were identified. No additional ineligible non-randomized studies (NRS) were included in this updated review. Twenty other ineligible studies were previously retrieved for further analysis despite not meeting the pre-specified criteria. Ten studies were retrospective or were literature reviews. Three studies were prospective, however they were limited to tumor recurrence and volumetric analysis and extent of resection. One study was a population-based parallel cohort in Norway, but not an RCT. Four studies were RCTs, however patients were randomized with respect to varying radiotherapy regimens to assess timing and dose of radiation. One RCT was on high-grade gliomas (HGGs) and not LGG. Finally, one RCT evaluated diffusion tensor imaging (DTI)-based neuro-navigation for surgical resection. Since the last version of this review, no new studies have been identified for inclusion and currently there are no RCTs or CCTs available on which to base definitive clinical decisions. Therefore, physicians must approach each case individually and weigh the risks and benefits of each intervention until further evidence is available. Some retrospective studies and non-randomized prospective studies do seem to suggest improved OS and seizure control correlating to higher extent of resection. Future research could focus on RCTs to determine outcomes benefits for biopsy versus resection.

  19. 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

  20. 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

  1. Comparative anatomical analysis of the transcallosal-transchoroidal and transcallosal-transforniceal-transchoroidal approaches to the third ventricle.

    PubMed

    Vitorino Araujo, João Luiz; Veiga, José C E; Wen, Hung Tzu; de Andrade, Almir F; Teixeira, Manoel J; Otoch, José P; Rhoton, Albert L; Preul, Mark C; Spetzler, Robert F; Figueiredo, Eberval G

    2016-11-04

    OBJECTIVE Access to the third ventricle is a veritable challenge to neurosurgeons. In this context, anatomical and morphometric studies are useful for establishing the limitations and advantages of a particular surgical approach. The transchoroidal approach is versatile and provides adequate exposure of the middle and posterior regions of the third ventricle. However, the fornix column limits the exposure of the anterior region of the third ventricle. There is evidence that the unilateral section of the fornix column has little effect on cognitive function. This study compared the anatomical exposure afforded by the transforniceal-transchoroidal approach with that of the transchoroidal approach. In addition, a morphometric evaluation of structures that are relevant to and common in the 2 approaches was performed. METHODS The anatomical exposure provided by the transcallosal-transchoroidal and transcallosal-transforniceal-transchoroidal approaches was compared in 8 fresh cadavers, using a neuronavigation system. The working area, microsurgical exposure area, and angular exposure on the longitudinal and transversal planes of 2 anatomical targets (tuber cinereum and cerebral aqueduct) were compared. Additionally, the thickness of the right frontal lobe parenchyma, thickness of the corpus callosum trunk, and longitudinal diameter of the interventricular foramen were measured. The values obtained were submitted to statistical analysis using the Wilcoxon test. RESULTS In the quantitative evaluation, compared with the transchoroidal approach, the transforniceal-transchoroidal approach provided a greater mean working area (transforniceal-transchoroidal 150 ± 11 mm(2); transchoroidal 121 ± 8 mm(2); p < 0.05), larger mean microsurgical exposure area (transforniceal-transchoroidal 101 ± 9 mm(2); transchoroidal 80 ± 5 mm(2); p < 0.05), larger mean angular exposure area on the longitudinal plane for the tuber cinereum (transforniceal-transchoroidal 71° ± 7