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Noorizadeh N, Varner JA, Birg L, Williard T, Rezaie R, Wheless J, Narayana S. Comparing the efficacy of awake and sedated MEG to TMS in mapping hand sensorimotor cortex in a clinical cohort. Neuroimage Clin 2024; 41:103562. [PMID: 38215622 PMCID: PMC10821581 DOI: 10.1016/j.nicl.2024.103562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 11/19/2023] [Accepted: 01/07/2024] [Indexed: 01/14/2024]
Abstract
Non-invasive methods such as Transcranial Magnetic Stimulation (TMS) and magnetoencephalography (MEG) aid in the pre-surgical evaluation of patients with epilepsy or brain tumor to identify sensorimotor cortices. MEG requires sedation in children or patients with developmental delay. However, TMS can be applied to awake patients of all ages with any cognitive abilities. In this study, we compared the efficacy of TMS with MEG (in awake and sedated states) in identifying the hand sensorimotor areas in patients with epilepsy or brain tumors. We identified 153 patients who underwent awake- (n = 98) or sedated-MEG (n = 55), along with awake TMS for hand sensorimotor mapping as part of their pre-surgical evaluation. TMS involved stimulating the precentral gyrus and recording electromyography responses, while MEG identified the somatosensory cortex during median nerve stimulation. Awake-MEG had a success rate of 92.35 % and TMS had 99.49 % (p-value = 0.5517). However, in the sedated-MEG cohort, TMS success rate of 95.61 % was significantly higher compared to MEG's 58.77 % (p-value = 0.0001). Factors affecting mapping success were analyzed. Logistic regression across the entire cohort identified patient sedation as the lone significant predictor, contrary to age, lesion, metal, and number of antiseizure medications (ASMs). A subsequent analysis replaced sedation with anesthetic drug dosage, revealing no significant predictors impacting somatosensory mapping success under sedation. This study yields insights into the utility of TMS and MEG in mapping hand sensorimotor cortices and underscores the importance of considering factors that influence eloquent cortex mapping limitations during sedation.
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Affiliation(s)
- Negar Noorizadeh
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States; Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, TN, United States
| | - Jackie Austin Varner
- Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, TN, United States
| | - Liliya Birg
- Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, TN, United States
| | - Theresa Williard
- Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, TN, United States
| | - Roozbeh Rezaie
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States; Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, TN, United States
| | - James Wheless
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States; Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, TN, United States
| | - Shalini Narayana
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States; Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, TN, United States; Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, United States.
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Iannotti GR, Nadin I, Ivanova V, Tourdot Q, Lascano AM, Momjian S, Schaller KL, Lovblad KO, Grouiller F. Specificity of Quantitative Functional Brain Mapping with Arterial Spin-Labeling for Preoperative Assessment. AJNR Am J Neuroradiol 2023; 44:1302-1308. [PMID: 37857448 PMCID: PMC10631521 DOI: 10.3174/ajnr.a8006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 08/28/2023] [Indexed: 10/21/2023]
Abstract
BACKGROUND AND PURPOSE Arterial spin-labeling is a noninvasive MR imaging technique allowing direct and quantitative measurement of brain perfusion. Arterial spin-labeling is well-established in clinics for investigating the overall cerebral perfusion, but it is still occasionally employed during tasks. The typical contrast for functional MR imaging is blood oxygen level-dependent (BOLD) imaging, whose specificity could be biased in neurologic patients due to altered neurovascular coupling. This work aimed to validate the use of functional ASL as a noninvasive tool for presurgical functional brain mapping. This is achieved by comparing the spatial accuracy of functional ASL with transcranial magnetic stimulation as the criterion standard. MATERIALS AND METHODS Twenty-eight healthy participants executed a motor task and received a somatosensory stimulation, while BOLD imaging and arterial spin-labeling were acquired simultaneously. Transcranial magnetic stimulation was subsequently used to define hand somatotopy. RESULTS Functional ASL was found more adjacent to transcranial magnetic stimulation than BOLD imaging, with a significant shift along the inferior-to-superior direction. With respect to BOLD imaging, functional ASL was localized significantly more laterally, anteriorly, and inferiorly during motor tasks and pneumatic stimulation. CONCLUSIONS Our results confirm the specificity of functional ASL in targeting the regional neuronal excitability. Functional ASL could be considered as a valid supplementary technique to BOLD imaging for presurgical mapping when spatial accuracy is crucial for delineating eloquent cortex.
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Affiliation(s)
- Giannina R Iannotti
- From the Division of Neuroradiology, Diagnostic Department (G.R.I., K.O.L.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
- Department of Neurosurgery (G.R.I., I.N., V.I., S.M., K.L.S.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Isaure Nadin
- Department of Neurosurgery (G.R.I., I.N., V.I., S.M., K.L.S.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Vladimira Ivanova
- Department of Neurosurgery (G.R.I., I.N., V.I., S.M., K.L.S.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Quentin Tourdot
- Faculty of Pharmacy (Q.T.), University of Montpellier, Montpellier, France
| | - Agustina M Lascano
- Division of Neurology (A.M.L.), Department of Clinical Neuroscience, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Shahan Momjian
- Department of Neurosurgery (G.R.I., I.N., V.I., S.M., K.L.S.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Karl L Schaller
- Department of Neurosurgery (G.R.I., I.N., V.I., S.M., K.L.S.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Karl O Lovblad
- From the Division of Neuroradiology, Diagnostic Department (G.R.I., K.O.L.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Frederic Grouiller
- Swiss Centre for Affective Sciences (F.G.), University of Geneva, Geneva, Switzerland
- Center for Biomedical Imaging (F.G.), MRI University of Geneva Cognitive and Affective Neuroimaging Section, Geneva, Switzerland
- Laboratory of Neurology and Imaging of Cognition (F.G.), Department of Basic Neurosciences, University of Geneva, Geneva, Switzerland
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Jafarian A, Hughes LE, Adams NE, Lanskey JH, Naessens M, Rouse MA, Murley AG, Friston KJ, Rowe JB. Neurochemistry-enriched dynamic causal models of magnetoencephalography, using magnetic resonance spectroscopy. Neuroimage 2023; 276:120193. [PMID: 37244323 DOI: 10.1016/j.neuroimage.2023.120193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 05/11/2023] [Accepted: 05/24/2023] [Indexed: 05/29/2023] Open
Abstract
We present a hierarchical empirical Bayesian framework for testing hypotheses about neurotransmitters' concertation as empirical prior for synaptic physiology using ultra-high field magnetic resonance spectroscopy (7T-MRS) and magnetoencephalography data (MEG). A first level dynamic causal modelling of cortical microcircuits is used to infer the connectivity parameters of a generative model of individuals' neurophysiological observations. At the second level, individuals' 7T-MRS estimates of regional neurotransmitter concentration supply empirical priors on synaptic connectivity. We compare the group-wise evidence for alternative empirical priors, defined by monotonic functions of spectroscopic estimates, on subsets of synaptic connections. For efficiency and reproducibility, we used Bayesian model reduction (BMR), parametric empirical Bayes and variational Bayesian inversion. In particular, we used Bayesian model reduction to compare alternative model evidence of how spectroscopic neurotransmitter measures inform estimates of synaptic connectivity. This identifies the subset of synaptic connections that are influenced by individual differences in neurotransmitter levels, as measured by 7T-MRS. We demonstrate the method using resting-state MEG (i.e., task-free recording) and 7T-MRS data from healthy adults. Our results confirm the hypotheses that GABA concentration influences local recurrent inhibitory intrinsic connectivity in deep and superficial cortical layers, while glutamate influences the excitatory connections between superficial and deep layers and connections from superficial to inhibitory interneurons. Using within-subject split-sampling of the MEG dataset (i.e., validation by means of a held-out dataset), we show that model comparison for hypothesis testing can be highly reliable. The method is suitable for applications with magnetoencephalography or electroencephalography, and is well-suited to reveal the mechanisms of neurological and psychiatric disorders, including responses to psychopharmacological interventions.
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Affiliation(s)
- Amirhossein Jafarian
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, United Kingdom; MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK.
| | - Laura E Hughes
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, United Kingdom; MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK.
| | - Natalie E Adams
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, United Kingdom.
| | - Juliette H Lanskey
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK.
| | - Michelle Naessens
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, United Kingdom; MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK.
| | - Matthew A Rouse
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, United Kingdom; MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK.
| | - Alexander G Murley
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, United Kingdom.
| | - Karl J Friston
- The Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, United Kingdom.
| | - James B Rowe
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, United Kingdom; MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, UK.
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Pre-Operative Functional Mapping in Patients with Brain Tumors by fMRI and MEG: Advantages and Disadvantages in the Use of One Technique over the Other. Life (Basel) 2023; 13:life13030609. [PMID: 36983765 PMCID: PMC10051860 DOI: 10.3390/life13030609] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 02/17/2023] [Accepted: 02/20/2023] [Indexed: 02/24/2023] Open
Abstract
Pre-operative mapping of brain functions is crucial to plan neurosurgery and investigate potential plasticity processes. Due to its availability, functional magnetic resonance imaging (fMRI) is widely used for this purpose; on the other hand, the demanding cost and maintenance limit the use of magnetoencephalography (MEG), despite several studies reporting its accuracy in localizing brain functions of interest in patient populations. In this review paper, we discuss the strengths and weaknesses of both techniques, from a methodological perspective first; then, we scrutinized and commented on the findings from 16 studies, identified by a database search, that made pre-operative assessments using both techniques in patients with brain tumors. We commented on the results by accounting for study limitations associated with small sample sizes and variability in the used tasks. Overall, we found that, although some studies reported the superiority for MEG, the majority of them underlined the complementary use of these techniques and suggested assessment using both. Indeed, both fMRI and MEG present some disadvantages, although the development of novel devices and processing procedures has enabled ever more accurate assessments. In particular, the development of new, more feasible MEG devices will allow widespread availability of this technique and its routinely combined use with fMRI.
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5
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Spooner RK, Madhavan D, Aizenberg MR, Wilson TW. Retrospective comparison of motor and somatosensory MEG mapping-Considerations for better clinical applications. Neuroimage Clin 2022; 35:103045. [PMID: 35597033 PMCID: PMC9123261 DOI: 10.1016/j.nicl.2022.103045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 04/29/2022] [Accepted: 05/09/2022] [Indexed: 11/17/2022]
Abstract
MEG is a clinically validated tool for presurgical functional mapping. The success rate for MEG somatosensory and motor mapping is not fully known. Comprehensive mapping protocols increase the accuracy of sensorimotor mapping. Major sources of mapping failures include low SNR, magnetic artifacts, and motion. Recommendations for improving mapping success rates in the future are discussed.
While magnetoencephalography (MEG) has proven to be a valuable and reliable tool for presurgical functional mapping of eloquent cortices for at least two decades, widespread use of this technique by clinicians has remained elusive. This modest application may be attributable, at least in part, to misunderstandings regarding the success rate of such mapping procedures, as well as the primary sources contributing to mapping failures. To address this, we conducted a retrospective comparison of sensorimotor functional mapping success rates in 141 patients with epilepsy and 75 tumor patients from the Center for MEG in Omaha, NE. Neurosurgical candidates either completed motor mapping (i.e., finger tapping paradigm), somatosensory mapping (i.e., peripheral stimulation paradigm), or both motor and somatosensory protocols during MEG. All MEG data underwent subsequent time-domain averaging and source localization of left and right primary motor (M1) and somatosensory (S1) cortices was conducted using a single equivalent dipole model. Successful mapping was determined based on dipole goodness of fit metrics ∼ 95%, as well as an accurate and conceivable spatial correspondence to precentral and postcentral gyri for M1 and S1, respectively. Our results suggest that mapping M1 in epilepsy and tumor patients was on average 94.5% successful, when patients only completed motor mapping protocols. In contrast, mapping S1 was successful 45–100% of the time in these patient groups when they only completed somatosensory mapping paradigms. Importantly, Z-tests for independent proportions revealed that the percentage of successful S1 mappings significantly increased to ∼ 94% in epilepsy patients who completed both motor/somatosensory mapping protocols during MEG. Together, these data suggest that ordering more comprehensive mapping procedures (e.g., both motor and somatosensory protocols for a collective sensorimotor network) may substantially increase the accuracy of presurgical functional mapping by providing more extensive data from which to base interpretations. Moreover, clinicians and magnetoencephalographers should be considerate of the major contributors to mapping failures (i.e., low SNR, excessive motion and magnetic artifacts) in order to further increase the percentage of cases achieving successful mapping of eloquent cortices.
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Affiliation(s)
- Rachel K Spooner
- Institute for Human Neuroscience, Boys Town National Research Hospital, Omaha, NE, USA; College of Medicine, University of Nebraska Medical Center, Omaha, NE, USA; Institute of Clinical Neuroscience and Medical Psychology, Heinrich-Heine University, Düsseldorf, Germany.
| | - Deepak Madhavan
- Institute for Human Neuroscience, Boys Town National Research Hospital, Omaha, NE, USA
| | | | - Tony W Wilson
- Institute for Human Neuroscience, Boys Town National Research Hospital, Omaha, NE, USA; College of Medicine, University of Nebraska Medical Center, Omaha, NE, USA; Department of Pharmacology & Neuroscience, Creighton University, Omaha, NE, USA
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6
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Jaatela J, Aydogan DB, Nurmi T, Vallinoja J, Piitulainen H. Identification of Proprioceptive Thalamocortical Tracts in Children: Comparison of fMRI, MEG, and Manual Seeding of Probabilistic Tractography. Cereb Cortex 2022; 32:3736-3751. [PMID: 35040948 PMCID: PMC9433422 DOI: 10.1093/cercor/bhab444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 11/05/2021] [Accepted: 11/06/2021] [Indexed: 11/16/2022] Open
Abstract
Studying white matter connections with tractography is a promising approach to understand the development of different brain processes, such as proprioception. An emerging method is to use functional brain imaging to select the cortical seed points for tractography, which is considered to improve the functional relevance and validity of the studied connections. However, it is unknown whether different functional seeding methods affect the spatial and microstructural properties of the given white matter connection. Here, we compared functional magnetic resonance imaging, magnetoencephalography, and manual seeding of thalamocortical proprioceptive tracts for finger and ankle joints separately. We showed that all three seeding approaches resulted in robust thalamocortical tracts, even though there were significant differences in localization of the respective proprioceptive seed areas in the sensorimotor cortex, and in the microstructural properties of the obtained tracts. Our study shows that the selected functional or manual seeding approach might cause systematic biases to the studied thalamocortical tracts. This result may indicate that the obtained tracts represent different portions and features of the somatosensory system. Our findings highlight the challenges of studying proprioception in the developing brain and illustrate the need for using multimodal imaging to obtain a comprehensive view of the studied brain process.
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Affiliation(s)
- Julia Jaatela
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo FI-02150, Finland
| | - Dogu Baran Aydogan
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo FI-02150, Finland
- Department of Psychiatry, Helsinki University Hospital, Helsinki FI-00029, Finland
- A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio FI-70211, Finland
| | - Timo Nurmi
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo FI-02150, Finland
- Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä FI-40014, Finland
| | - Jaakko Vallinoja
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo FI-02150, Finland
| | - Harri Piitulainen
- Address correspondence to Harri Piitulainen, associate professor, Harri Piitulainen, Faculty of Sport and Health Sciences, University of Jyväskylä, P.O. BOX 35, FI-40014, Finland.
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Sensorimotor Mapping With MEG: An Update on the Current State of Clinical Research and Practice With Considerations for Clinical Practice Guidelines. J Clin Neurophysiol 2021; 37:564-573. [PMID: 33165229 DOI: 10.1097/wnp.0000000000000481] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
In this article, we present the clinical indications and advances in the use of magnetoencephalography to map the primary sensorimotor (SM1) cortex in neurosurgical patients noninvasively. We emphasize the advantages of magnetoencephalography over sensorimotor mapping using functional magnetic resonance imaging. Recommendations to the referring physicians and the clinical magnetoencephalographers to achieve appropriate sensorimotor cortex mapping using magnetoencephalography are proposed. We finally provide some practical advice for the use of corticomuscular coherence, cortico-kinematic coherence, and mu rhythm suppression in this indication. Magnetoencephalography should now be considered as a method of reference for presurgical functional mapping of the sensorimotor cortex.
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Weiss Lucas C, Nettekoven C, Neuschmelting V, Oros-Peusquens AM, Stoffels G, Viswanathan S, Rehme AK, Faymonville AM, Shah NJ, Langen KJ, Goldbrunner R, Grefkes C. Invasive versus non-invasive mapping of the motor cortex. Hum Brain Mapp 2020; 41:3970-3983. [PMID: 32588936 PMCID: PMC7469817 DOI: 10.1002/hbm.25101] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 05/05/2020] [Accepted: 06/08/2020] [Indexed: 11/26/2022] Open
Abstract
Precise and comprehensive mapping of somatotopic representations in the motor cortex is clinically essential to achieve maximum resection of brain tumours whilst preserving motor function, especially since the current gold standard, that is, intraoperative direct cortical stimulation (DCS), holds limitations linked to the intraoperative setting such as time constraints or anatomical restrictions. Non‐invasive techniques are increasingly relevant with regard to pre‐operative risk‐assessment. Here, we assessed the congruency of neuronavigated transcranial magnetic stimulation (nTMS) and functional magnetic resonance imaging (fMRI) with DCS. The motor representations of the hand, the foot and the tongue regions of 36 patients with intracranial tumours were mapped pre‐operatively using nTMS and fMRI and by intraoperative DCS. Euclidean distances (ED) between hotspots/centres of gravity and (relative) overlaps of the maps were compared. We found significantly smaller EDs (11.4 ± 8.3 vs. 16.8 ± 7.0 mm) and better spatial overlaps (64 ± 38% vs. 37 ± 37%) between DCS and nTMS compared with DCS and fMRI. In contrast to DCS, fMRI and nTMS mappings were feasible for all regions and patients without complications. In summary, nTMS seems to be the more promising non‐invasive motor cortex mapping technique to approximate the gold standard DCS results.
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Affiliation(s)
- Carolin Weiss Lucas
- Medical Faculty and University Hospital, Center for Neurosurgery, University of Cologne, Cologne, Germany
| | - Charlotte Nettekoven
- Medical Faculty and University Hospital, Center for Neurosurgery, University of Cologne, Cologne, Germany
| | - Volker Neuschmelting
- Medical Faculty and University Hospital, Center for Neurosurgery, University of Cologne, Cologne, Germany
| | | | - Gabriele Stoffels
- Research Centre Jülich, Institute of Neuroscience and Medicine, Jülich, Germany
| | | | - Anne K Rehme
- Research Centre Jülich, Institute of Neuroscience and Medicine, Jülich, Germany.,Medical Faculty and University Hospital, Department of Neurology, University of Cologne, Cologne, Germany
| | - Andrea Maria Faymonville
- Medical Faculty and University Hospital, Center for Neurosurgery, University of Cologne, Cologne, Germany
| | - N Jon Shah
- Research Centre Jülich, Institute of Neuroscience and Medicine, Jülich, Germany.,Department of Neurology, RWTH Aachen University, University Clinic Aachen, Aachen, Germany
| | - Karl Josef Langen
- Research Centre Jülich, Institute of Neuroscience and Medicine, Jülich, Germany
| | - Roland Goldbrunner
- Medical Faculty and University Hospital, Center for Neurosurgery, University of Cologne, Cologne, Germany
| | - Christian Grefkes
- Research Centre Jülich, Institute of Neuroscience and Medicine, Jülich, Germany.,Medical Faculty and University Hospital, Department of Neurology, University of Cologne, Cologne, Germany
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Kreidenhuber R, De Tiège X, Rampp S. Presurgical Functional Cortical Mapping Using Electromagnetic Source Imaging. Front Neurol 2019; 10:628. [PMID: 31249552 PMCID: PMC6584755 DOI: 10.3389/fneur.2019.00628] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 05/28/2019] [Indexed: 02/03/2023] Open
Abstract
Preoperative localization of functionally eloquent cortex (functional cortical mapping) is common clinical practice in order to avoid or reduce postoperative morbidity. This review aims at providing a general overview of magnetoencephalography (MEG) and high-density electroencephalography (hdEEG) based methods and their clinical role as compared to common alternatives for functional cortical mapping of (1) verbal language function, (2) sensorimotor cortex, (3) memory, (4) visual, and (5) auditory cortex. We highlight strengths, weaknesses and limitations of these functional cortical mapping modalities based on findings in the recent literature. We also compare their performance relative to other non-invasive functional cortical mapping methods, such as functional Magnetic Resonance Imaging (fMRI), Transcranial Magnetic Stimulation (TMS), and to invasive methods like the intracarotid Amobarbital Test (WADA-Test) or intracranial investigations.
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Affiliation(s)
- Rudolf Kreidenhuber
- Department of Neurology, Christian-Doppler Medical Center, Paracelsus Medical University, Salzburg, Austria.,Centre for Cognitive Neuroscience, University of Salzburg, Salzburg, Austria
| | - Xavier De Tiège
- Laboratoire de Cartographie Fonctionelle du Cerveau, ULB Neuroscience Institute, Université Libre de Bruxelles, Brussels, Belgium.,Department of Functional Neuroimaging, Service of Nuclear Medicine, CUB Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
| | - Stefan Rampp
- Department of Neurosurgery, University Hospital Erlangen, Erlangen, Germany.,Department of Neurosurgery, University Hospital Halle, Halle, Germany
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Zimmermann M, Rössler K, Kaltenhäuser M, Grummich P, Brandner N, Buchfelder M, Dörfler A, Kölble K, Stadlbauer A. Comparative fMRI and MEG localization of cortical sensorimotor function: Bimodal mapping supports motor area reorganization in glioma patients. PLoS One 2019; 14:e0213371. [PMID: 30845241 PMCID: PMC6405066 DOI: 10.1371/journal.pone.0213371] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 02/19/2019] [Indexed: 12/31/2022] Open
Abstract
INTRODUCTION Preoperative functional mapping in the vicinity of brain lesion is of high importance for avoiding complications in surgical management. However, space-occupying lesions may lead to functional reorganization or decreased BOLD activity. METHODS Therefore in 13 patients with cerebral gliomas or brain arterio-venous malformations/ hemangioma fMRI- and MEG-based cortical localizations of motor and somatosensory cortical activation pattern were compared in order to investigate their congruency. RESULTS Localization of cortical sensorimotor areas with fMRI and MEG showed good congruency with a mean spatial distance of around 10 mm, with differences depending on the localization method. The smallest mean differences for the centroids were found for MEF with MNE 8 mm and SEF with sLORETA 8 mm. Primary motor area (M1) reorganization was found in 5 of 12 patients in fMRI and confirmed with MEG data. In these 5 patients with M1-reorganization the distance between the border of the fMRI-based cortical M1-localization and the tumor border on T1w MR images varied between 0-4 mm, which was significant (P = 0.025) different to the distance in glioma patients without M1-reorganization (5-26 mm). CONCLUSION Our multimodal preoperative mapping approach combining fMRI and MEG reveals a high degree of spatial congruence and provided high evidence for the presence of motor cortex reorganization.
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Affiliation(s)
- Max Zimmermann
- Department of Neurosurgery, University of Erlangen-Nürnberg, Erlangen, Germany
- * E-mail:
| | - Karl Rössler
- Department of Neurosurgery, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Martin Kaltenhäuser
- Department of Neurosurgery, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Peter Grummich
- Department of Neurosurgery, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Nadja Brandner
- Department of Neurosurgery, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Michael Buchfelder
- Department of Neurosurgery, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Arnd Dörfler
- Department of Neuroradiology, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Konrad Kölble
- Department of Neuropathology, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Andreas Stadlbauer
- Department of Neurosurgery, University of Erlangen-Nürnberg, Erlangen, Germany
- Institute of Medical Radiology, University Clinic of St. Pölten, St. Pölten, Austria
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11
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Presurgical electromagnetic functional brain mapping in refractory focal epilepsy. ZEITSCHRIFT FUR EPILEPTOLOGIE 2018. [DOI: 10.1007/s10309-018-0189-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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12
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Nimsky C, Carl B. Historical, Current, and Future Intraoperative Imaging Modalities. Neurosurg Clin N Am 2017; 28:453-464. [DOI: 10.1016/j.nec.2017.05.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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13
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De Tiège X, Lundqvist D, Beniczky S, Seri S, Paetau R. Current clinical magnetoencephalography practice across Europe: Are we closer to use MEG as an established clinical tool? Seizure 2017. [PMID: 28623727 DOI: 10.1016/j.seizure.2017.06.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Affiliation(s)
- Xavier De Tiège
- Department of Functional Neuroimaging, Service of Nuclear Medicine, CUB Hôpital Erasme, Université libre de Bruxelles (ULB), Brussels, Belgium; Laboratoire de Cartographie fonctionnelle du Cerveau, ULB Neuroscience Institute, Université libre de Bruxelles (ULB), Brussels, Belgium.
| | - Daniel Lundqvist
- NatMEG, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Sándor Beniczky
- Department of Clinical Neurophysiology, Danish Epilepsy Center, Dianalund, Denmark; Department of Clinical Neurophysiology, Aarhus University, Aarhus, Denmark
| | - Stefano Seri
- School of Life and Health Sciences, Aston Brain Centre, Aston University, Birmingham, United Kingdom
| | - Ritva Paetau
- Departments of Paediatric Neurology and Clinical Neurophysiology, Helsinki University Central Hospital, Helsinki, Finland
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Localized N20 Component of Somatosensory Evoked Magnetic Fields in Frontoparietal Brain Tumor Patients Using Noise-Normalized Approaches. Clin Neuroradiol 2017; 28:267-281. [PMID: 28116447 DOI: 10.1007/s00062-017-0557-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Accepted: 01/03/2017] [Indexed: 10/20/2022]
Abstract
PURPOSE To localize sensorimotor cortical activation in 10 patients with frontoparietal tumors using quantitative magnetoencephalography (MEG) with noise-normalized approaches. MATERIAL AND METHODS Somatosensory evoked magnetic fields (SEFs) were elicited in 10 patients with somatosensory tumors and in 10 control participants using electrical stimulation of the median nerve via the right and left wrists. We localized the N20m component of the SEFs using dynamic statistical parametric mapping (dSPM) and standardized low-resolution brain electromagnetic tomography (sLORETA) combined with 3D magnetic resonance imaging (MRI). The obtained coordinates were compared between groups. Finally, we statistically evaluated the N20m parameters across hemispheres using non-parametric statistical tests. RESULTS The N20m sources were accurately localized to Brodmann area 3b in all members of the control group and in seven of the patients; however, the sources were shifted in three patients relative to locations outside the primary somatosensory cortex (SI). Compared with the affected (tumor) hemispheres in the patient group, N20m amplitudes and the strengths of the current sources were significantly lower in the unaffected hemispheres and in both hemispheres of the control group. These results were consistent for both dSPM and sLORETA approaches. CONCLUSION Tumors in the sensorimotor cortex lead to cortical functional reorganization and an increase in N20m amplitude and current-source strengths. Noise-normalized approaches for MEG analysis that are integrated with MRI show accurate and reliable localization of sensorimotor function.
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15
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Reliable recording and analysis of MEG-based corticokinematic coherence in the presence of strong magnetic artifacts. Clin Neurophysiol 2016; 127:1460-1469. [DOI: 10.1016/j.clinph.2015.07.030] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 07/08/2015] [Accepted: 07/25/2015] [Indexed: 11/21/2022]
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16
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17
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Stippich C, Blatow M, Garcia M. Task-Based Presurgical Functional MRI in Patients with Brain Tumors. CLINICAL FUNCTIONAL MRI 2015. [DOI: 10.1007/978-3-662-45123-6_4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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18
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Lascano AM, Grouiller F, Genetti M, Spinelli L, Seeck M, Schaller K, Michel CM. Surgically relevant localization of the central sulcus with high-density somatosensory-evoked potentials compared with functional magnetic resonance imaging. Neurosurgery 2014; 74:517-26. [PMID: 24463494 DOI: 10.1227/neu.0000000000000298] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Resection of abnormal brain tissue lying near the sensorimotor cortex entails precise localization of the central sulcus. Mapping of this area is achieved by applying invasive direct cortical electrical stimulation. However, noninvasive methods, particularly functional magnetic resonance imaging (fMRI), are also used. As a supplement to fMRI, localization of somatosensory-evoked potentials (SEPs) recorded with an electroencephalogram (EEG) has been proposed, but has not found its place in clinical practice. OBJECTIVE To assess localization accuracy of the hand somatosensory cortex with SEP source imaging. METHODS We applied electrical source imaging in 49 subjects, recorded with high-density EEG (256 channels). We compared it with fMRI in 18 participants and with direct cortical electrical stimulation in 6 epileptic patients. RESULTS Comparison of SEP source imaging with fMRI indicated differences of 3 to 8 mm, with the exception of the mesial-distal orientation, where variances of up to 20 mm were found. This discrepancy is explained by the fact that the source maximum of the first SEP peak is localized deep in the central sulcus (area 3b), where information initially arrives. Conversely, fMRI showed maximal signal change on the lateral surface of the postcentral gyrus (area 1), where sensory information is integrated later in time. Electrical source imaging and fMRI showed mean Euclidean distances of 13 and 14 mm, respectively, from the contacts where electrocorticography elicited sensory phenomena of the contralateral upper limb. CONCLUSION SEP source imaging, based on high-density EEG, reliably identifies the depth of the central sulcus. Moreover, it is a simple, flexible, and relatively inexpensive alternative to fMRI.
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Affiliation(s)
- Agustina M Lascano
- *Department of Neurology, University Hospital of Geneva, Geneva, Switzerland; ‡Functional Brain Mapping Laboratory, Department of Neurology, University Hospital of Geneva and University Medical Centre, Geneva, Switzerland; §Department of Radiology and Medical Informatics, University Hospital of Geneva, Geneva, Switzerland; ¶Department of Neurosurgery, University Hospitals of Geneva, Geneva, Switzerland
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Gabriel M, Brennan NP, Peck KK, Holodny AI. Blood oxygen level dependent functional magnetic resonance imaging for presurgical planning. Neuroimaging Clin N Am 2014; 24:557-71. [PMID: 25441500 DOI: 10.1016/j.nic.2014.07.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Functional magnetic resonance imaging (fMRI) has become a common tool for presurgical sensorimotor mapping, and is a significant preoperative asset for tumors located adjacent to the central sulcus. fMRI has changed surgical options for many patients. This noninvasive tool allows for easy display and integration with other neuroimaging techniques. Although fMRI is a useful preoperative tool, it is not perfect. Tumors that affect the normal vascular coupling of neuronal activity will affect fMRI measurements. This article discusses the usefulness of blood oxygen level dependent (BOLD) fMRI with regard to preoperative motor mapping.
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Affiliation(s)
- Meredith Gabriel
- Functional MRI Laboratory, Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Nicole P Brennan
- Functional MRI Laboratory, Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Kyung K Peck
- Functional MRI Laboratory, Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
| | - Andrei I Holodny
- Functional MRI Laboratory, Department of Radiology, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA.
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20
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Differences Between MEG and High-Density EEG Source Localizations Using a Distributed Source Model in Comparison to fMRI. Brain Topogr 2014; 28:87-94. [DOI: 10.1007/s10548-014-0405-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Accepted: 09/22/2014] [Indexed: 10/24/2022]
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21
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Cho JM, Kim EH, Kim J, Lee SK, Kim SH, Lee KS, Chang JH. Clinical use of diffusion tensor image-merged functional neuronavigation for brain tumor surgeries: review of preoperative, intraoperative, and postoperative data for 123 cases. Yonsei Med J 2014; 55:1303-9. [PMID: 25048489 PMCID: PMC4108816 DOI: 10.3349/ymj.2014.55.5.1303] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
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.
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Affiliation(s)
- Jin Mo Cho
- Department of Neurosurgery, International St. Mary's Hospital, Incheon, Korea. ; Department of Medicine, Graduate School, Yonsei University, Seoul, Korea
| | - Eui Hyun Kim
- Department of Neurosurgery, Yonsei University College of Medicine, Seoul, Korea. ; Brain Tumor Center, Yonsei University College of Medicine, Seoul, Korea. ; Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Jinna Kim
- Department of Radiology, Yonsei University College of Medicine, Seoul, Korea. ; Brain Tumor Center, Yonsei University College of Medicine, Seoul, Korea
| | - Seung Koo Lee
- Department of Radiology, Yonsei University College of Medicine, Seoul, Korea. ; Brain Tumor Center, Yonsei University College of Medicine, Seoul, Korea
| | - Sun Ho Kim
- Department of Neurosurgery, Yonsei University College of Medicine, Seoul, Korea. ; Brain Tumor Center, Yonsei University College of Medicine, Seoul, Korea. ; Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Kyu Sung Lee
- Department of Neurosurgery, Yonsei University College of Medicine, Seoul, Korea. ; Brain Tumor Center, Yonsei University College of Medicine, Seoul, Korea. ; Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Jong Hee Chang
- Department of Neurosurgery, Yonsei University College of Medicine, Seoul, Korea. ; Brain Tumor Center, Yonsei University College of Medicine, Seoul, Korea. ; Brain Research Institute, Yonsei University College of Medicine, Seoul, Korea
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22
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Nimsky C, Ganslandt O, Buchfelder M, Fahlbusch R. Intraoperative visualization for resection of gliomas: the role of functional neuronavigation and intraoperative 1.5 T MRI. Neurol Res 2013; 28:482-7. [PMID: 16808876 DOI: 10.1179/016164106x115125] [Citation(s) in RCA: 157] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVE To investigate how functional neuronavigation and intraoperative high-field magnetic resonance imaging (MRI) influence glioma resection. METHODS One hundred and thirty-seven patients [World Health Organization (WHO) grade I: 20; II: 19; III: 41; IV: 57] underwent resection for supratentorial gliomas in an operative suite equipped with intraoperative high-field MRI and microscope-based neuronavigation. Besides standard anatomical image data including T1- and T2-weighted sequences, various functional data from magnetoencephalography (n=37), functional MRI (n=65), positron emission tomography (n=8), MR spectroscopy (n=28) and diffusion tensor imaging (n=55) were integrated in the navigational setup. RESULTS Intraoperative MRI showed primary complete resection in 27% of all patients (I: 50%; II: 53%; III: 2%; IV: 28%). In 41% of all patients (I: 40%; II: 26%; III: 66%; IV: 28%) the resection was extended owing to intraoperative MRI increasing the percentage of complete resections to 40% (I: 70%; II: 58%; III: 17%; IV: 40%). Integrated application of functional navigation resulted in low post-operative morbidity with a transient new neurological deficit in 10.2% (paresis: 8.8% and speech disturbance: 1.4%) decreasing to a permanent deficit in 2.9% (four of 137 patients with a new or increased paresis). CONCLUSIONS The combination of intraoperative MRI and functional navigation allows safe extended resections in glioma surgery. However, despite extended resections, still in the majority of the grade III and IV gliomas no gross total resection could be achieved owing to the extension of the tumor into eloquent brain areas. Intraoperative MRI data can be used to localize the tumor remnants reliably and compensate for the effects of brain shift.
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Affiliation(s)
- Christopher Nimsky
- Department of Neurosurgery, University Erlangen-Nuremberg, Erlangen, Germany.
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23
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Comprehensive Functional Mapping Scheme for Non-Invasive Primary Sensorimotor Cortex Mapping. Brain Topogr 2012; 26:511-23. [DOI: 10.1007/s10548-012-0271-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Accepted: 12/15/2012] [Indexed: 10/27/2022]
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Otsuka T, Dan H, Dan I, Sase M, Sano T, Tsuzuki D, Fujita A, Sasaguri K, Okada N, Kusama M, Jinbu Y, Watanabe E. Effect of local anesthesia on trigeminal somatosensory-evoked magnetic fields. J Dent Res 2012; 91:1196-201. [PMID: 23018817 DOI: 10.1177/0022034512462398] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
For objective neurophysiological evaluation of the function of the trigeminal system, magnetoencephalography- based TSEF (trigeminal somatosensory-evoked field) assessment would be valuable in providing spatial and temporal profiles of cortical responses. However, this necessitates knowledge of how TSEF varies with trigeminal nerve dysfunctions. We introduced a conduction block of the trigeminal nerve using local anesthesia (lidocaine) to temporally mimic nerve dysfunctions, and monitored TSEF changes. Following an electrical stimulation of the lower lip, a magnetic response with peak latency of approximately 20 ms was identified in all participants. Dipole for the peak was estimated on the post-central gyrus in the participant's own magnetic resonance image. After normalization to Montreal Neurological Institute (MNI) space and inter-participant data integration, the summary equivalent current dipole localization among participants remained in the post-central gyrus, suggesting validity of the use of MNI space. Partial anesthesia of the lower lip led to a loss of the waveform characteristics of TSEF for electrical stimulation to the trigeminal nerve. We verified that the 20-ms latency cortical response of TSEF components localized at the primary sensory cortex can serve as a robust neurofunctional marker of experimental trigeminal nerve dysfunction.
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Affiliation(s)
- T Otsuka
- Department of Craniofacial Growth and Developmental Dentistry, Kanagawa Dental College, 82 Inaoka-cho, Yokosuka, Kanagawa 238-8580, Japan
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25
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Impaired hemodynamic response in the ischemic brain assessed with BOLD fMRI. Neuroimage 2012; 61:579-90. [DOI: 10.1016/j.neuroimage.2012.04.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2011] [Revised: 03/29/2012] [Accepted: 04/01/2012] [Indexed: 11/21/2022] Open
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Abstract
Noninvasive neuroimaging aids in surgical planning and in counseling patients about possible risks of surgery. Magnetoencephalography (MEG) performs the most common types of surgical planning that the neurosurgeon faces, including localization of epileptic discharges, determination of the hemispheric dominance of verbal processing, and the ability to locate eloquent cortex. MEG is most useful when it is combined with structural imaging, most commonly with structural magnetic resonance (MR) imaging and MR diffusion imaging. This article reviews the history of clinical MEG, introduces the basic concepts about the biophysics of MEG, and outlines the basic neurosurgical applications of MEG.
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Affiliation(s)
- Steven M Stufflebeam
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, USA.
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27
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Abstract
Multimodal functional navigation enables removing a tumor close to eloquent brain areas with low postoperative deficits, whereas additional intraoperative imaging ensures that the maximum extent of the resection can be achieved and updates the image data compensating for the effects of brain shift. Intraoperative imaging beyond standard anatomic imaging, that is, intraoperative functional magnetic resonance imaging (fMRI) and especially intraoperative diffusion tensor imaging (DTI), add further safety for complex tumor resections. This article discusses the acquisition of intraoperative fMRI, DTI, and imaging.
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Affiliation(s)
- Christopher Nimsky
- Department of Neurosurgery, University Marburg, Baldingerstrasse, Marburg 35033, Germany.
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28
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Forster MT, Hattingen E, Senft C, Gasser T, Seifert V, Szelényi A. Navigated Transcranial Magnetic Stimulation and Functional Magnetic Resonance Imaging: Advanced Adjuncts in Preoperative Planning for Central Region Tumors. Neurosurgery 2011; 68:1317-24; discussion 1324-5. [DOI: 10.1227/neu.0b013e31820b528c] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Abstract
BACKGROUND:
Tumor resection in the vicinity of the motor cortex poses a challenge to all neurosurgeons. For preoperative assessment of eloquent cortical areas, functional magnetic resonance imaging (fMRI) is used, whereas intraoperatively, direct cortical stimulation (DCS) is performed. Navigated transcranial magnetic stimulation (nTMS) is comparable to DCS in activating cortical pyramidal neurons.
OBJECTIVE:
To evaluate the reliability of nTMS compared with fMRI and DCS for preoperative resection planning of centrally located tumors.
METHODS:
In a prospective series, 11 patients (ages, 20-63 years; mean, 41.9 ± 14.9 years, 2 women) with tumors located in or adjacent to the motor cortex were evaluated for surgery. fMRI and nTMS were applied for preoperative assessment of the extent of tumor resection. A 3-dimensional anatomic data set with superimposed fMRI data was integrated in the eXimia Navigated Brain Stimulation station for ensuing motor cortex mapping by nTMS. Responses from nTMS were evaluated by electromyographic response. During surgery, the coordinates of each DCS site were unambiguously defined and integrated into neuronavigation. A post hoc comparison of the coordinates of nTMS, fMRI, and DCS was performed.
RESULTS:
Distances from nTMS to DCS (10.5 ± 5.67 mm) were significantly smaller than those from fMRI to DCS (15.0 ± 7.6 mm).
CONCLUSION:
nTMS anticipates information usually only enabled by DCS and therefore allows surgical planning in eloquent cortex surgery.
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Affiliation(s)
- Marie-Thérèse Forster
- Department of Neurosurgery, Johann Wolfgang Goethe University Hospital, Frankfurt am Main, Germany
| | - Elke Hattingen
- Department of Neuroradiology, Johann Wolfgang Goethe University Hospital, Frankfurt am Main, Germany
| | - Christian Senft
- Department of Neurosurgery, Johann Wolfgang Goethe University Hospital, Frankfurt am Main, Germany
| | - Thomas Gasser
- Department of Neurosurgery, Johann Wolfgang Goethe University Hospital, Frankfurt am Main, Germany
| | - Volker Seifert
- Department of Neurosurgery, Johann Wolfgang Goethe University Hospital, Frankfurt am Main, Germany
| | - Andrea Szelényi
- Department of Neurosurgery, Johann Wolfgang Goethe University Hospital, Frankfurt am Main, Germany
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Martino J, Honma SM, Findlay AM, Guggisberg AG, Owen JP, Kirsch HE, Berger MS, Nagarajan SS. Resting functional connectivity in patients with brain tumors in eloquent areas. Ann Neurol 2011; 69:521-32. [PMID: 21400562 DOI: 10.1002/ana.22167] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Revised: 06/23/2010] [Accepted: 07/16/2010] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Resection of brain tumors adjacent to eloquent areas represents a challenge in neurosurgery. If maximal resection is desired without inducing postoperative neurological deficits, a detailed knowledge of the functional topography in and around the tumor is crucial. The aim of the present work is to evaluate the value of preoperative magnetoencephalography (MEG) imaging of functional connectivity to predict the results of intraoperative electrical stimulation (IES) mapping, the clinical gold standard for neurosurgical localization of functional areas. METHODS Resting-state whole-cortex MEG recordings were obtained from 57 consecutive subjects with focal brain tumors near or within motor, sensory, or language areas. Neural activity was estimated using adaptive spatial filtering algorithms, and the mean imaginary coherence between the rest of the brain and voxels in and around brain tumors were compared to the mean imaginary coherence between the rest of the brain and contralesional voxels as an index of functional connectivity. IES mapping was performed in all subjects. The cortical connectivity pattern near the tumor was compared to the IES results. RESULTS Maps with decreased resting-state functional connectivity in the entire tumor area had a negative predictive value of 100% for absence of eloquent cortex during IES. Maps showing increased resting-state functional connectivity within the tumor area had a positive predictive value of 64% for finding language, motor, or sensory cortical sites during IES mapping. INTERPRETATION Preoperative resting state MEG connectivity analysis is a useful noninvasive tool to evaluate the functionality of the tissue surrounding tumors within eloquent areas, and could potentially contribute to surgical planning and patient counseling.
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Affiliation(s)
- Juan Martino
- Department of Neurological Surgery, Hospital Universitario Marqués de Valdecilla, Instituto de Formación e Investigación Marqués de Valdecilla, Santander, Cantabria, Spain
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30
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Gasser T, Szelenyi A, Senft C, Muragaki Y, Sandalcioglu IE, Sure U, Nimsky C, Seifert V. Intraoperative MRI and functional mapping. ACTA NEUROCHIRURGICA. SUPPLEMENT 2011; 109:61-5. [PMID: 20960322 DOI: 10.1007/978-3-211-99651-5_10] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
The integration of functional and anatomical data into neuronavigation is an established standard of care in many neurosurgical departments. Yet, this method has limitations as in most cases the data are acquired prior to surgery. Due to brain-shift the accurate presentation of functional as well as anatomical structures declines in the course of surgery. In consequence, the acquisition of information during surgery about the brain's current functional state is of specific interest. The advancement of imaging technologies (e.g. fMRI, MEG, Intraoperative Optical Intrinsic Signal Imaging--IOIS) and neurophysiological techniques and the advent of intraoperative MRI all had a major impact on neurosurgery. The combination of modalities such as neurophysiology and intraoperative MRI (ioMRI), as well as the acquisition of functional MRI during surgery (ifMRI) are in the focus of this work. Especially the technical aspects and safety issues are elucidated.
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Affiliation(s)
- Thomas Gasser
- Department of Neurosurgery, University of Duisburg-Essen, Hufelandstr. 55, 45147 Essen, Germany.
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Pre-surgical planning and MR-tractography utility in brain tumour resection. Eur Radiol 2009; 19:2798-808. [DOI: 10.1007/s00330-009-1483-6] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2008] [Revised: 04/15/2009] [Accepted: 04/24/2009] [Indexed: 10/20/2022]
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Gaetz W, Cheyne D, Rutka JT, Drake J, Benifla M, Strantzas S, Widjaja E, Holowka S, Tovar-Spinoza Z, Otsubo H, Pang EW. Presurgical Localization of Primary Motor Cortex in Pediatric Patients with Brain Lesions by the Use of Spatially Filtered Magnetoencephalography. Oper Neurosurg (Hagerstown) 2009; 64:ons177-85; discussion ons186. [DOI: 10.1227/01.neu.0000316433.10913.32] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Abstract
Objective:
The objective of this study was to confirm the efficacy of spatially filtered magnetoencephalography for the preoperative localization of primary motor cortex in pediatric patients with focal lesions in the region of the sensorimotor cortex.
Methods:
We recorded movement-related magnetoencephalographic activity in 10 pediatric patients (age range, 7–18 years; mean age, 12.5 years) undergoing presurgical evaluation for focal brain lesion resection. Participants made transient movements of the right and left index finger in response to a visual cue. The premovement motor field component in the averaged brain response was localized with a newly developed beamformer spatial filter algorithm. Cortical mapping of motor cortex intraoperatively was conducted in 5 of the 10 patients.
Results:
The motor field time-locked to electromyography onset was successfully localized to cortical areas corresponding to the hand region primary motor cortex in 95% of cases (9 of 10 from nonlesional hemisphere; 10 of 10 from lesional hemisphere). Intraoperative electrocortical stimulation activated the expected muscles at motor field coregistered cortical source locations in all cases tested (n = 5). Using these methods, we also found that displacement of the sensorimotor cortex by space-occupying tumors did not interfere with the localization of motor cortex.
Conclusion:
We conclude that noninvasive localization of the primary motor cortex can be reliably performed by using spatially filtered magnetoencephalography techniques, which provide a robust and accurate measurement of motor cortical function for the purpose of surgical guidance.
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Affiliation(s)
- William Gaetz
- Department of Diagnostic Imaging, Hospital for Sick Children, and Department of Medical Imaging, University of Toronto, Toronto, Canada
| | - Douglas Cheyne
- Department of Diagnostic Imaging, Hospital for Sick Children, and Department of Medical Imaging, University of Toronto, Toronto, Canada
| | - James T. Rutka
- Division of Neurosurgery, Hospital for Sick Children, Toronto, Canada
| | - James Drake
- Division of Neurosurgery, Hospital for Sick Children, Toronto, Canada
| | - Mony Benifla
- Division of Neurosurgery, Hospital for Sick Children, Toronto, Canada
| | - Samuel Strantzas
- Division of Neurosurgery, Hospital for Sick Children, Toronto, Canada
| | - Elysa Widjaja
- Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Canada
| | - Stephanie Holowka
- Department of Diagnostic Imaging, Hospital for Sick Children, Toronto, Canada
| | | | - Hiroshi Otsubo
- Division of Neurology, Hospital for Sick Children, Toronto, Canada
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Zotev VS, Matlashov AN, Volegov PL, Savukov IM, Espy MA, Mosher JC, Gomez JJ, Kraus RH. Microtesla MRI of the human brain combined with MEG. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2008; 194:115-20. [PMID: 18619876 PMCID: PMC2556894 DOI: 10.1016/j.jmr.2008.06.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2008] [Revised: 06/13/2008] [Accepted: 06/13/2008] [Indexed: 05/22/2023]
Abstract
One of the challenges in functional brain imaging is integration of complementary imaging modalities, such as magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI). MEG, which uses highly sensitive superconducting quantum interference devices (SQUIDs) to directly measure magnetic fields of neuronal currents, cannot be combined with conventional high-field MRI in a single instrument. Indirect matching of MEG and MRI data leads to significant co-registration errors. A recently proposed imaging method--SQUID-based microtesla MRI--can be naturally combined with MEG in the same system to directly provide structural maps for MEG-localized sources. It enables easy and accurate integration of MEG and MRI/fMRI, because microtesla MR images can be precisely matched to structural images provided by high-field MRI and other techniques. Here we report the first images of the human brain by microtesla MRI, together with auditory MEG (functional) data, recorded using the same seven-channel SQUID system during the same imaging session. The images were acquired at 46 microT measurement field with pre-polarization at 30 mT. We also estimated transverse relaxation times for different tissues at microtesla fields. Our results demonstrate feasibility and potential of human brain imaging by microtesla MRI. They also show that two new types of imaging equipment--low-cost systems for anatomical MRI of the human brain at microtesla fields, and more advanced instruments for combined functional (MEG) and structural (microtesla MRI) brain imaging--are practical.
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Affiliation(s)
- Vadim S Zotev
- Los Alamos National Laboratory, Applied Modern Physics Group, MS D454, Los Alamos, NM 87545, USA.
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35
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Pujol J, Deus J, Acebes JJ, Villanueva A, Aparicio A, Soriano-Mas C, Ortiz H, Conesa G. Identification of the sensorimotor cortex with functional MRI: frequency and actual contribution in a neurosurgical context. J Neuroimaging 2008; 18:28-33. [PMID: 18190492 DOI: 10.1111/j.1552-6569.2007.00175.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE We assessed the actual frequency of motor functional MRI (fMRI) in a neurosurgical environment and estimated the extent to which it aided surgeons' identifications of the sensorimotor cortex. METHODS During five consecutive years, an fMRI protocol aimed at generating a selective activation of the hand cortical area was prescribed to 147 patients showing a centrally located space-occupying lesion, which represents 6.7% of all assisted surgical candidates showing an intracranial mass. Three senior neurosurgeons indicated the position of the sensorimotor cortex on two different anatomical displays, reporting confidence ratings for each decision. RESULTS The sensorimotor cortex could not be identified in 16.5% of cases using conventional anatomical MRI, and in 15% of cases using 3-dimensional reconstructions. In an additional 12.5% of cases, the neurosurgeons were not confident when they correctly identified the sensorimotor cortex. The tumor distorting effect on central region anatomy significantly contributed to sensorimotor cortex misidentification. fMRI, by contrast, showed a selective activation indicating the position of the sensorimotor cortex in all but 4% of cases. CONCLUSIONS In our neurosurgical environment, fMRI was prescribed to a selected group of surgical candidates showing a centrally located brain lesion. Compared to conventional anatomical imaging, fMRI does appear to improve the identification of sensorimotor cortex.
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Affiliation(s)
- Jesus Pujol
- Institut d'Alta Tecnologia--PRBB, CRC Corporació Sanitària, Barcelona, Spain.
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36
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Preoperative blood oxygen level-dependent functional magnetic resonance imaging in patients with gliomas involving the motor cortical areas. Chin Med J (Engl) 2008. [DOI: 10.1097/00029330-200804010-00011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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37
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Gharabaghi A, Tatagiba M. [Expectations and demands of function preserving neurosurgery on imaging]. Z Med Phys 2008; 17:232-6. [PMID: 18254544 DOI: 10.1016/j.zemedi.2007.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Modern neurosurgery applies diagnostic imaging, surgical planning and image-guidance with the aim of preservation of neurological function. Thereby, high precision and comprehensive presentation of the acquired multimodal data sets are mandatory for accurate localisation and registration. Morphological and functional information on cortical und subcortical structures should define target and anti-targets and provide the surgeon with an intuitive orientation within the operative field and, thereby, increase the safety of the procedure. Preoperative surgical planning and simulation, as well as intraoperative image-update of the surgical field are expected to further improve the operative result. The functional and specific structural imaging findings for image-guidance need to be validated intraoperatively, e.g. by electrophysiological stimulation, in terms of their sensitivity and specifity. Finally, image-guidance has to prove its impact on overall neurosurgical outcome and patients' quality of live on follow up exams.
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38
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Nimsky C, Ganslandt O, Weigel D, von Keller B, Stadlbauer A, Akutsu H, Hammen T, Buchfelder M. Intraoperative Tractography and Neuronavigation of the Pyramidal Tract( Functional Neurophysiological Monitoring for Neurosurgery). ACTA ACUST UNITED AC 2008. [DOI: 10.7887/jcns.17.21] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Ch Nimsky
- Department of Neurosurgery, University Erlangen-Nuremberg
| | - O Ganslandt
- Department of Neurosurgery, University Erlangen-Nuremberg
| | - D Weigel
- Department of Neurosurgery, University Erlangen-Nuremberg
| | - B von Keller
- Department of Neurosurgery, University Erlangen-Nuremberg
| | - A Stadlbauer
- Department of Neurosurgery, University Erlangen-Nuremberg
| | - H Akutsu
- Department of Neurosurgery, University Erlangen-Nuremberg
| | - T Hammen
- Department of Neurology, University Erlangen-Nuremberg
| | - M Buchfelder
- Department of Neurosurgery, University Erlangen-Nuremberg
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39
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Intraoperative Navigation and Fluorescence Imagings in Malignant Glioma Surgery. Keio J Med 2008; 57:155-61. [DOI: 10.2302/kjm.57.155] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Jun SC, George JS, Kim W, Paré-Blagoev J, Plis S, Ranken DM, Schmidt DM. Bayesian brain source imaging based on combined MEG/EEG and fMRI using MCMC. Neuroimage 2007; 40:1581-94. [PMID: 18314351 DOI: 10.1016/j.neuroimage.2007.12.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2007] [Revised: 11/19/2007] [Accepted: 12/14/2007] [Indexed: 10/22/2022] Open
Abstract
A number of brain imaging techniques have been developed in order to investigate brain function and to develop diagnostic tools for various brain disorders. Each modality has strengths as well as weaknesses compared to the others. Recent work has explored how multiple modalities can be integrated effectively so that they complement one another while maintaining their individual strengths. Bayesian inference employing Markov Chain Monte Carlo (MCMC) techniques provides a straightforward way to combine disparate forms of information while dealing with the uncertainty in each. In this paper we introduce methods of Bayesian inference as a way to integrate different forms of brain imaging data in a probabilistic framework. We formulate Bayesian integration of magnetoencephalography (MEG) data and functional magnetic resonance imaging (fMRI) data by incorporating fMRI data into a spatial prior. The usefulness and feasibility of the method are verified through testing with both simulated and empirical data.
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Affiliation(s)
- Sung C Jun
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
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41
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Merhof D, Soza G, Stadlbauer A, Greiner G, Nimsky C. Correction of susceptibility artifacts in diffusion tensor data using non-linear registration. Med Image Anal 2007; 11:588-603. [PMID: 17664081 DOI: 10.1016/j.media.2007.05.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2005] [Revised: 02/16/2007] [Accepted: 05/18/2007] [Indexed: 11/27/2022]
Abstract
Diffusion tensor imaging can be used to localize major white matter tracts within the human brain. For surgery of tumors near eloquent brain areas such as the pyramidal tract this information is of importance to achieve an optimal resection while avoiding post-operative neurological deficits. However, due to the small bandwidth of echo planar imaging, diffusion tensor images suffer from susceptibility artifacts resulting in positional shifts and distortion. As a consequence, the fiber tracts computed from echo planar imaging data are spatially distorted. We present an approach based on non-linear registration using Bézier functions to efficiently correct distortions due to susceptibility artifacts. The approach makes extensive use of graphics hardware to accelerate the non-linear registration procedure. An improvement presented in this paper is a more robust and efficient optimization strategy based on simultaneous perturbation stochastic approximation (SPSA). Since the accuracy of non-linear registration is crucial for the value of the presented correction method, two techniques were applied in order to prove the quality of the proposed framework. First, the registration accuracy was evaluated by recovering a known transformation with non-linear registration. Second, landmark-based evaluation of the registration method for anatomical and diffusion tensor data was performed. The registration was then applied to patients with lesions adjacent to the pyramidal tract in order to compensate for susceptibility artifacts. The effect of the correction on the pyramidal tract was then quantified by measuring the position of the tract before and after registration. As a result, the distortions observed in phase encoding direction were most prominent at the cortex and the brainstem. The presented approach allows correcting fiber tract distortions which is an important prerequisite when tractography data are integrated into a stereotactic setup for intra-operative guidance.
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Affiliation(s)
- D Merhof
- Computer Graphics Group, University of Erlangen-Nuremberg, Am Weichselgarten 9, 91058, Erlangen, Germany.
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Willemse RB, de Munck JC, van't Ent D, Ris P, Baayen JC, Stam CJ, Vandertop WP. MAGNETOENCEPHALOGRAPHIC STUDY OF POSTERIOR TIBIAL NERVE STIMULATION IN PATIENTS WITH INTRACRANIAL LESIONS AROUND THE CENTRAL SULCUS. Neurosurgery 2007; 61:1209-17; discussion 1217-8. [DOI: 10.1227/01.neu.0000306099.45764.5c] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Abstract
OBJECTIVE
To study interhemispheric differences of somatosensory evoked field (SEF) characteristics and the spatial distribution of equivalent current dipole sources in patients with unilateral hemispheric lesions around the central sulcus region.
METHODS
In 17 patients with perirolandic lesions, averaged somatosensory responses after posterior tibial nerve stimulation at the ankle were recorded with magnetoencephalography. Dipole source solutions in the affected (AH) and unaffected (UH) hemispheres were analyzed and compared for latency, equivalent current dipole strength, root mean square, and spatial distribution in relation to clinical findings.
RESULTS
Three main SEF components, P45m, N60m, and P75m, were identified in the hemisphere contralateral to the stimulated nerve. Dipole strength for the P45m component was significantly higher in the AH compared with the UH. SEF characteristics in the AH and UH showed no significant differences with respect to component latency or dipole strength of the N60m and P75m components. Interdipole location asymmetries exceeded 1.0 cm in 71% of the patients. Comparison of the posterior tibial nerve evoked responses (P45m and N60m) in patients with motor deficits and patients without deficits showed that these responses are enlarged in the AH when perirolandic lesions are present. Patients with motor deficits also showed an increased response for P45m in the UH.
CONCLUSION
The results of posterior tibial nerve SEFs suggest spatial and functional changes in the somatosensory network as a result of perirolandic lesions with a possible relationship with clinical symptoms. The results can provide further basis for the evaluation of cortical changes in the presence of perirolandic lesions.
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Affiliation(s)
- Ronald B. Willemse
- Department of Neurosurgery, VU University Medical Center, Amsterdam, The Netherlands
| | - Jan C. de Munck
- Department of Physics and Medical Technology, VU University Medical Center, Amsterdam, The Netherlands
| | - Dennis van't Ent
- Departments of Physics and Medical Technology and Biological Psychology, VU University Medical Center, Amsterdam, The Netherlands
| | - Peterjan Ris
- Department of Clinical Neurophysiology, VU University Medical Center, Amsterdam, The Netherlands
| | - Johannes C. Baayen
- Department of Neurosurgery, VU University Medical Center, Amsterdam, The Netherlands
| | - Cornelis J. Stam
- Department of Clinical Neurophysiology, VU University Medical Center, Amsterdam, The Netherlands
| | - W. Peter Vandertop
- Department of Neurosurgery, VU University Medical Center, Amsterdam, The Netherlands
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Chen X, Weigel D, Ganslandt O, Buchfelder M, Nimsky C. Diffusion tensor imaging and white matter tractography in patients with brainstem lesions. Acta Neurochir (Wien) 2007; 149:1117-31; discussion 1131. [PMID: 17712509 DOI: 10.1007/s00701-007-1282-2] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2007] [Accepted: 07/25/2007] [Indexed: 10/22/2022]
Abstract
BACKGROUND Diffusion tensor imaging (DTI) and white matter tractography (WMT) are promising techniques for estimating the course, extent, and connectivity patterns of the white matter (WM) structures in the human brain. In this study, we investigated the ability of DTI and WMT to visualize white matter tract involvement for the preoperative surgical planning and postoperative assessment of brainstem lesions. METHODS Preoperative and postoperative DTI data (echo-planar, 1.5T) were retrospectively analyzed in 10 patients with brainstem lesions (3 diffuse, 7 focal). WMT applying a tensor deflection algorithm was used to reconstruct WM tracts adjacent to the lesions. Reconstructed tracts included corticospinal tracts and medial lemnisci. The clinical and imaging follow-up data were also compared and analyzed. FINDINGS WMT revealed a series of tract alteration patterns including deviation, deformation, infiltration, and apparent tract interruption. WMT reconstructions showed that the major WM tracts were preserved during surgery and improved in position and appearance postoperatively. These findings correlated with the improvement or preservation of neurological function as determined by clinical assessment. CONCLUSIONS Compared with the information provided by conventional MR imaging, DTI and WMT provided superior quantification and visualization of lesion involvement in eloquent fibre tracts of the brainstem. Moreover, DTI and WMT were found to be beneficial for white matter recognition in the neurosurgical planning and postoperative assessment of brainstem lesions.
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MESH Headings
- Adolescent
- Adult
- Aged
- Astrocytoma/diagnosis
- Astrocytoma/pathology
- Astrocytoma/surgery
- Brain Damage, Chronic/diagnosis
- Brain Damage, Chronic/pathology
- Brain Damage, Chronic/surgery
- Brain Mapping
- Brain Stem Neoplasms/diagnosis
- Brain Stem Neoplasms/pathology
- Brain Stem Neoplasms/surgery
- Cranial Nerve Diseases/diagnosis
- Cranial Nerve Diseases/pathology
- Diffusion Magnetic Resonance Imaging
- Dominance, Cerebral/physiology
- Female
- Hemangioma, Cavernous, Central Nervous System/diagnosis
- Hemangioma, Cavernous, Central Nervous System/pathology
- Hemangioma, Cavernous, Central Nervous System/surgery
- Humans
- Image Processing, Computer-Assisted
- Imaging, Three-Dimensional
- Male
- Middle Aged
- Nerve Fibers, Myelinated/pathology
- Nerve Net/pathology
- Nerve Net/surgery
- Neurologic Examination
- Neuronavigation
- Pons/pathology
- Pons/surgery
- Postoperative Complications/diagnosis
- Postoperative Complications/pathology
- Pyramidal Tracts/pathology
- Pyramidal Tracts/surgery
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Affiliation(s)
- X Chen
- Department of Neurosurgery, University Erlangen-Nürnberg, Erlangen, Germany.
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Romano A, Ferrante M, Cipriani V, Fasoli F, Ferrante L, D'Andrea G, Fantozzi LM, Bozzao A. Role of magnetic resonance tractography in the preoperative planning and intraoperative assessment of patients with intra-axial brain tumours. Radiol Med 2007; 112:906-920. [PMID: 17891343 DOI: 10.1007/s11547-007-0181-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2006] [Accepted: 02/12/2007] [Indexed: 10/22/2022]
Abstract
PURPOSE This study was conducted to assess the possibility of identifying precise white matter tracts situated in proximity to intracranial tumours, to define the anatomical and topographical relations between the same white matter tracts and the tumour, to verify the possibility of integrating tractographic images in the context of a package of three-dimensional anatomical images to send to the neuronavigation system, to assess the impact of this information on surgical planning, and to analyse, both pre-and postoperatively, the patient's clinical conditions as an index of the functional integrity of the fibres themselves. MATERIALS AND METHODS Twenty-five patients underwent diffusion tensor study prior to neurosurgery. With the use of dedicated software, relative colour maps were obtained and the trajectories of the white matter tracts adjacent to the tumour were reconstructed in three dimensions. These were then processed for preoperative planning. Planning, which was performed with the neuronavigator, was based on analysis of the location of the course of the main white matter tracts adjacent to the lesion (pyramidal tract, optic radiation and arcuate fasciculus). Two neurosurgeons were asked whether the tractography images had modified the access and/or intraoperative approach to the tumour. All patients were clinically assessed both pre-and postoperatively 1 month after the procedure to define the presence of symptoms related to the involvement of the white matter tracts studied and therefore to assess the integrity of the fibres after the operation. RESULTS In one patient, the tumour was situated away from all the tracts studied and did not compress them in any way. Overall, 40/75 tracts studied had no anatomical relation with the tumour, were not displaced by the tumour or could not be visualised in their entire course. Analysis of the remaining 35 white matter tracts led to an a priori change in the surgical approach for corticotomy in four patients (16%), with no disagreement between the two neurosurgeons and an impact on the extent of resection during surgery in 17 (68%), thus an overall impact on the surgical procedure in 80% of cases. Eight patients showed no symptoms related to the involvement of the white matter tracts studied. In the remaining 17 patients, the symptoms were related to involvement of the pyramidal tract, arcuate fasciculus or optic radiation. At 1-month follow-up, one previously asymptomatic patient reported a speech disorder (transcortical sensory dysphasia); in the remaining 24, symptoms remained unchanged, with a tendency to improvement in 14/17 with symptoms related to involvement of white matter tracts studied. CONCLUSIONS Magnetic resonance (MR) tractography offers the neurosurgeon an anatomical panoramic view that can improve surgical planning for the resection of intracranial tumours. Despite the high incidence of cases in which the lesion is responsible for changes that hinder the reconstruction of white matter tracts, the technique can change the surgical approach for corticotomy, defines the extent of resection and leads to some change in the procedure in 80% of cases. The improvement of pre-existing symptoms and the absence of new symptoms in the postoperative phase, in our opinion, confirms the value of the technique.
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Affiliation(s)
- A Romano
- Cattedra di Neuroradiologia, Università La Sapienza, Via di Grottarossa 1035, Rome, Italy.
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Kirsch HE, Zhu Z, Honma S, Findlay A, Berger MS, Nagarajan SS. Predicting the location of mouth motor cortex in patients with brain tumors by using somatosensory evoked field measurements. J Neurosurg 2007; 107:481-7. [PMID: 17886544 DOI: 10.3171/jns-07/09/0481] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Before resective brain surgery, localization of the functional regions is necessary to minimize postoperative deficits. The face area has been relatively difficult to map noninvasively by using functional imaging techniques. Preoperative localization of face somatosensory cortex with magnetoencephalography (MEG) may allow the surgeon to predict the location of mouth motor areas.
Methods
The authors compared the location of face somatosensory cortex obtained with somatosensory evoked fields during preoperative MEG with the mouth motor areas identified during intraoperative electrocortical stimulation (ECS) mapping in 13 patients undergoing resection of brain tumor.
Results
In this group of patients, ECS mouth motor sites were usually anterior and lateral to MEG localizations of lip somatosensory cortex. The consistent quantitative relationship between results of these two mapping procedures allows the practitioner to predict the location of mouth motor cortex based on noninvasive preoperative MEG measurements.
Conclusions
Based on this result, the authors suggest that somatosensory mapping using MEG can be used to guide intraoperative mapping and neurosurgical planning.
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Affiliation(s)
- Heidi E Kirsch
- University of California San Francisco Epilepsy Center, Department of Neurology, USA
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Stoeckel MC, Pollok B, Schnitzler A, Seitz RJ. Studying the human somatosensory hand area: A new way to compare fMRI and MEG. J Neurosci Methods 2007; 164:280-91. [PMID: 17597225 DOI: 10.1016/j.jneumeth.2007.05.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2006] [Revised: 04/03/2007] [Accepted: 05/13/2007] [Indexed: 10/23/2022]
Abstract
Valid localization is a prerequisite to study plasticity of the somatosensory cortex in humans. We compared the localizations of left and right thumb and little finger in the primary somatosensory cortex obtained with fMRI and MEG. Representations were investigated in 11 healthy right-handed subjects using echoplanar fMRI and 122-channel MEG together with electric finger stimulation. Activation observed with fMRI was based on an increase in the BOLD signal. Most of the activation clusters (71.1%) were located on the lateral surface of the postcentral gyrus. Representations of thumb and little finger were 17mm apart on average and consistently showed a somatotopic arrangement with the thumb representation inferior, lateral, and anterior to the representation of the little finger. Activation observed with MEG was modelled by equivalent current dipoles. Dipole localization was compatible with an assumed origin of activation within the posterior wall of the central sulcus. The Euclidian distance between corresponding dipoles was 11.5mm on average with deviations from the expected spatial arrangement of 35, 30, and 20% in the x-, y- und z-direction, respectively. Our study demonstrates how relative localization of somatosensory activations can serve as an indicator for localization validity when comparing different methods or studying somatosensory plasticity.
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Affiliation(s)
- Maria Cornelia Stoeckel
- Department of Neurology, University Hospital Düsseldorf, Moorenstr. 5, 40225 Düsseldorf, Germany.
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Tancredi LR, Brodie JD. The brain and behavior: limitations in the legal use of functional magnetic resonance imaging. AMERICAN JOURNAL OF LAW & MEDICINE 2007; 33:271-94. [PMID: 17910160 DOI: 10.1177/009885880703300206] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Brain imaging is one of the most remarkable technological advances towards understanding the relationship of behavior to brain anatomy and physiology. Brain images provide insight to understanding behavior. Additionally, the images themselves carry great impact, particularly when used to show differences in either the anatomy or the biological functioning of two different brains. For these reasons, brain images have increasingly been used in both criminal and civil trials.After describing some general features of brain imaging, we will focus on functional magnetic imaging (fMRI), as many believe this technology has the most potential for advancing our understanding of how parts of the brain function, including perhaps linking specific functions with cognition and behavior. Brain imaging as a field is vast and therefore our discussion will be limited. First, we will assess the advantages and limitations of fMRI, including research efforts towards standardizing equipment thereby assuring reliability and reproducibility.
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Abstract
OBJECT In this study the role of magnetic source imaging for preoperative motor mapping was evaluated by using a single-dipole localization method to analyze motor field data in 41 patients. METHODS Data from affected and unaffected hemispheres were collected in patients performing voluntary finger flexion movements. Somatosensory evoked field (SSEF) data were also obtained using tactile stimulation. Dipole localization using motor field (MF) data was successful in only 49% of patients, whereas localization with movement-evoked field (MEF) data was successful in 66% of patients. When the spatial distribution of MF and MEF dipoles in relation to SSEF dipoles was analyzed, the motor dipoles were not spatially distinct from somatosensory dipoles. CONCLUSIONS The findings in this study suggest that single-dipole localization for the analysis of motor data is not sufficiently sensitive and is nonspecific, and thus not clinically useful.
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Affiliation(s)
- Peter T Lin
- Department of Neurology, Stanford Hospital and Clinics, Stanford, California, USA
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Korvenoja A, Kirveskari E, Aronen HJ, Avikainen S, Brander A, Huttunen J, Ilmoniemi RJ, Jääskeläinen JE, Kovala T, Mäkelä JP, Salli E, Seppä M. Sensorimotor Cortex Localization: Comparison of Magnetoencephalography, Functional MR Imaging, and Intraoperative Cortical Mapping. Radiology 2006; 241:213-22. [PMID: 16908676 DOI: 10.1148/radiol.2411050796] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To prospectively evaluate magnetoencephalography (MEG) and functional magnetic resonance (MR) imaging, as compared with intraoperative cortical mapping, for identification of the central sulcus. MATERIALS AND METHODS Fifteen patients (six men, nine women; age range, 25-58 years) with a lesion near the primary sensorimotor cortex (13 gliomas, one cavernous hemangioma, and one meningioma) were examined after institutional review board approval and written informed consent from each patient were obtained. At MEG, evoked magnetic fields to median nerve stimulation were recorded; at functional MR imaging, hemodynamic responses to self-paced palmar flexion of the wrist were imaged. General linear model analysis with contextual clustering (P < .01) was used to analyze functional MR imaging data, and dipole modeling was used to analyze MEG data. MEG and functional MR localizations were compared with intraoperative cortical mappings. The distance from the area of functional MR imaging activation to the tumor margin was compared between the patients with discordant and those with concordant intraoperative mapping findings by using unpaired t testing. RESULTS MEG depicted the central sulcus correctly in all 15 patients, as verified at intraoperative mapping. The functional MR imaging localization results agreed with the intraoperative mappings in 11 patients. In all four patients with a false localization, the primary activation was in the postcentral sulcus region, but it did not differ significantly from the primary activation in the patients with correct localization with respect to proximity to the tumor (P = .38). Furthermore, at functional MR imaging, multiple nonprimary areas were activated, with considerable interindividual variation. CONCLUSION Although both MEG and functional MR imaging can provide useful information for neurosurgical planning, in the present study, MEG proved to be superior for locating the central sulcus. Activation of multiple nonprimary cerebral areas may confound the interpretation of functional MR imaging results.
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Affiliation(s)
- Antti Korvenoja
- Functional Brain Imaging Unit, Helsinki Brain Research Center, Medical Imaging Center, University of Helsinki, Helsinki, Finland.
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50
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Mäkelä JP, Forss N, Jääskeläinen J, Kirveskari E, Korvenoja A, Paetau R. Magnetoencephalography in Neurosurgery. Neurosurgery 2006; 59:493-510; discussion 510-1. [PMID: 16955031 DOI: 10.1227/01.neu.0000232762.63508.11] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Abstract
OBJECTIVE:
To present applications of magnetoencephalography (MEG) in studies of neurosurgical patients.
METHODS:
MEG maps magnetic fields generated by electric currents in the brain, and allows the localization of brain areas producing evoked sensory responses and spontaneous electromagnetic activity. The identified sources can be integrated with other imaging modalities, e.g., with magnetic resonance imaging scans of individual patients with brain tumors or intractable epilepsy, or with other types of brain imaging data.
RESULTS:
MEG measurements using modern whole-scalp instruments assist in tailoring individual therapies for neurosurgical patients by producing maps of functionally irretrievable cortical areas and by identifying cortical sources of interictal and ictal epileptiform activity. The excellent time resolution of MEG enables tracking of complex spaciotemporal source patterns, helping, for example, with the separation of the epileptic pacemaker from propagated activity. The combination of noninvasive mapping of subcortical pathways by magnetic resonance imaging diffusion tensor imaging with MEG source localization will, in the near future, provide even more accurate navigational tools for preoperative planning. Other possible future applications of MEG include the noninvasive estimation of language lateralization and the follow-up of brain plasticity elicited by central or peripheral neural lesions or during the treatment of chronic pain.
CONCLUSION:
MEG is a mature technique suitable for producing preoperative “road maps” of eloquent cortical areas and for localizing epileptiform activity.
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Affiliation(s)
- Jyrki P Mäkelä
- BioMag Laboratory, Engineering Centre, Helsinki University Central Hospital, Helsinki, Finland.
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