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Noorizadeh N, Rezaie R, Varner JA, Wheless JW, Fulton SP, Mudigoudar BD, Nevill L, Holder CM, Narayana S. Concordance between Wada, Transcranial Magnetic Stimulation, and Magnetoencephalography for Determining Hemispheric Dominance for Language: A Retrospective Study. Brain Sci 2024; 14:336. [PMID: 38671988 PMCID: PMC11047819 DOI: 10.3390/brainsci14040336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 03/15/2024] [Accepted: 03/28/2024] [Indexed: 04/28/2024] Open
Abstract
Determination of language hemispheric dominance (HD) in patients undergoing evaluation for epilepsy surgery has traditionally relied on the sodium amobarbital (Wada) test. The emergence of non-invasive methods for determining language laterality has increasingly shown to be a viable alternative. In this study, we assessed the efficacy of transcranial magnetic stimulation (TMS) and magnetoencephalography (MEG), compared to the Wada test, in determining language HD in a sample of 12 patients. TMS-induced speech errors were classified as speech arrest, semantic, or performance errors, and the HD was based on the total number of errors in each hemisphere with equal weighting of all errors (classic) and with a higher weighting of speech arrests and semantic errors (weighted). Using MEG, HD for language was based on the spatial extent of long-latency activity sources localized to receptive language regions. Based on the classic and weighted language laterality index (LI) in 12 patients, TMS was concordant with the Wada in 58.33% and 66.67% of patients, respectively. In eight patients, MEG language mapping was deemed conclusive, with a concordance rate of 75% with the Wada test. Our results indicate that TMS and MEG have moderate and strong agreement, respectively, with the Wada test, suggesting they could be used as non-invasive substitutes.
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Affiliation(s)
- Negar Noorizadeh
- Division of Pediatric Neurology, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN 38163, USA; (N.N.); (R.R.); (J.W.W.); (S.P.F.); (B.D.M.); (C.M.H.)
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN 38103, USA; (J.A.V.); (L.N.)
| | - Roozbeh Rezaie
- Division of Pediatric Neurology, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN 38163, USA; (N.N.); (R.R.); (J.W.W.); (S.P.F.); (B.D.M.); (C.M.H.)
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN 38103, USA; (J.A.V.); (L.N.)
| | - Jackie A. Varner
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN 38103, USA; (J.A.V.); (L.N.)
| | - James W. Wheless
- Division of Pediatric Neurology, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN 38163, USA; (N.N.); (R.R.); (J.W.W.); (S.P.F.); (B.D.M.); (C.M.H.)
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN 38103, USA; (J.A.V.); (L.N.)
| | - Stephen P. Fulton
- Division of Pediatric Neurology, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN 38163, USA; (N.N.); (R.R.); (J.W.W.); (S.P.F.); (B.D.M.); (C.M.H.)
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN 38103, USA; (J.A.V.); (L.N.)
| | - Basanagoud D. Mudigoudar
- Division of Pediatric Neurology, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN 38163, USA; (N.N.); (R.R.); (J.W.W.); (S.P.F.); (B.D.M.); (C.M.H.)
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN 38103, USA; (J.A.V.); (L.N.)
| | - Leigh Nevill
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN 38103, USA; (J.A.V.); (L.N.)
| | - Christen M. Holder
- Division of Pediatric Neurology, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN 38163, USA; (N.N.); (R.R.); (J.W.W.); (S.P.F.); (B.D.M.); (C.M.H.)
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN 38103, USA; (J.A.V.); (L.N.)
| | - Shalini Narayana
- Division of Pediatric Neurology, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN 38163, USA; (N.N.); (R.R.); (J.W.W.); (S.P.F.); (B.D.M.); (C.M.H.)
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN 38103, USA; (J.A.V.); (L.N.)
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN 38163, USA
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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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Voets NL, Bartsch AJ, Plaha P. Functional MRI applications for intra-axial brain tumours: uses and nuances in surgical practise. Br J Neurosurg 2023; 37:1544-1559. [PMID: 36148501 DOI: 10.1080/02688697.2022.2123893] [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: 03/18/2022] [Accepted: 09/07/2022] [Indexed: 11/02/2022]
Abstract
PURPOSE Functional MRI (fMRI) has well-established uses to inform risks and plan maximally safe approaches in neurosurgery. In the field of brain tumour surgery, however, fMRI is currently in a state of clinical equipoise due to debate around both its sensitivity and specificity. MATERIALS AND METHODS In this review, we summarise the role and our experience of fMRI in neurosurgery for gliomas and metastases. We discuss nuances in the conduct and interpretation of fMRI that, based on our practise, most directly impact fMRI's usefulness in the neurosurgical setting. RESULTS Illustrated examples in which fMRI in our hands directly influences the neurosurgical treatment of brain tumours include evaluating the probability and nature of functional risks, especially for language functions. These presurgical risk assessments, in turn, help to predict the resectability of tumours, select or deselect patients for awake surgery, indicate the need for neurophysiological monitoring and guide the optimal use of intra-operative stimulation mapping. A further emerging application of fMRI is in measuring functional adaptation of functional networks after (partial) surgery, of potential use in the timing of further surgery. CONCLUSIONS In appropriately selected patients with a clearly defined surgical question, fMRI offers a valuable complementary tool in the pre-surgical evaluation of brain tumours. However, there is a great need for standards in the administration and analysis of fMRI as much as in the techniques that it is commonly evaluated against. Surprisingly little data exists that evaluates the accuracy of fMRI not just against complementary methods, but in terms of its ultimate clinical aim of minimising post-surgical morbidity.
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Affiliation(s)
- Natalie L Voets
- Department of Neurosurgery, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
- GenesisCare Ltd, Oxford, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Andreas J Bartsch
- Department of Neuroradiology, University of Heidelberg, Heidelberg, Germany
| | - Puneet Plaha
- Department of Neurosurgery, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
- Nuffield Department of Neurosurgery, University of Oxford, Oxford, UK
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Multimodal Presurgical Evaluation of Medically Refractory Focal Epilepsy in Adults: An Update for Radiologists. AJR Am J Roentgenol 2022; 219:488-500. [PMID: 35441531 DOI: 10.2214/ajr.22.27588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Surgery is a potentially curative treatment option for patients with medically refractory focal epilepsy. Advanced neuroimaging modalities often improve surgical outcomes by contributing key information during the highly individualized surgical planning process and intraoperative localization. Hence, neuroradiologists play an integral role as part of the multidisciplinary management team. In this review, we initially present the conceptual background and practical framework of the presurgical evaluation process, including a description of the surgical treatment approaches in medically refractory focal epilepsy in adults. This background is followed by an overview of the advanced modalities commonly used during the presurgical workup at level IV epilepsy centers including diffusion imaging techniques, blood oxygen level dependent (BOLD) functional MRI (fMRI), PET, SPECT, and subtraction ictal SPECT, as well as by introductions to 7-T MRI and electrophysiologic techniques including electroencephalography (EEG) and magnetoencephalography (MEG). We also provide illustrative case examples of multimodal neuroimaging including PET/MRI, PET/MRI-DTI, subtraction ictal SPECT, and image-guided stereotactic planning with fMRI-DTI.
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Braden AA, Weatherspoon SE, Boardman T, Williard T, Adkins A, Gibbs SK, Wheless JW, Narayana S. Image-guided TMS is safe in a predominately pediatric clinical population. Clin Neurophysiol 2022; 137:193-206. [DOI: 10.1016/j.clinph.2022.01.133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 01/18/2022] [Accepted: 01/21/2022] [Indexed: 11/28/2022]
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Chowdhury T, Zeiler FA, Singh N, Gray KDR, Qadri A, Beiko J, Cappellani RB, West M. Awake Craniotomy Under 3-Tesla Intraoperative Magnetic Resonance Imaging: A Retrospective Descriptive Report and Canadian Institutional Experience. J Neurosurg Anesthesiol 2022; 34:e46-e51. [PMID: 32482989 DOI: 10.1097/ana.0000000000000699] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Accepted: 04/23/2020] [Indexed: 11/27/2022]
Abstract
BACKGROUND The role of high-field 3-Tesla intraoperative magnetic resonance imaging (I-MRI) during awake craniotomy (AC) has not been extensively studied. We report the feasibility and safety of AC during 3-Tesla I-MRI. METHODS This retrospective descriptive report compared 3 groups: AC with minimal sedation and I-MRI; I-MRI-guided craniotomy under general anesthesia (GA), and; AC without I-MRI. Perioperative factors, surgical, anesthetic and radiologic complications, and postoperative morbidity and mortality were recorded. RESULTS Overall, 85 patients are included in this report. Five of 23 patients (22%) who underwent AC with I-MRI had anesthetic complications (nausea/vomiting and conversion to GA) compared with 3 of 40 (8%) who underwent I-MRI-guided craniotomy under GA (nausea/vomiting during extubation, and arrhythmia). Intraoperative surgical complications (seizures and speech deficits) occurred in 5 patients (22%) who underwent AC and I-MRI, excessive intraoperative bleeding occurred in 2 patients (5%) who had I-MRI-guided craniotomy under GA, and 4 of 22 (18%) patients who underwent AC without I-MRI experienced neurological complications (seizures, motor deficits, and transient loss of consciousness). Eight patients (20%) who had I-MRI with GA had postoperative complications, largely neurological. The duration of surgery and anesthesia were shortest in the group of patients receiving AC without I-MRI. Seventy-three percent of the patients in this group had residual tumor postoperatively compared with 44% and 38% in those having I-MRI with AC or GA, respectively. Patients who underwent I-MRI-guided craniotomy with GA had the highest morbidity (8%) at hospital discharge. CONCLUSIONS Our institutional experience suggests that AC under 3-Tesla I-MRI could be an option for glioma resection, although firm conclusions cannot be drawn given the limited and heterogenous nature of our data. Future multicenter trials comparing anesthetic and imaging modalities for glioma resection are recommended.
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Affiliation(s)
- Tumul Chowdhury
- Department of Anesthesiology, Perioperative and Pain Medicine, Max Rady College of Medicine, Rady Faculty of Health Sciences
| | - Frederick A Zeiler
- Department of Surgery, Section-Neurosurgery, Clincian Investigator Program, Max Rady College of Medicine, Rady Faculty of Health Sciences
- Department of Medicine, Division of Anesthesia, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK
| | | | - Kristen D R Gray
- Max Rady College of Medicine, University of Manitoba, Winnipeg, MB, Canada
| | - Ali Qadri
- Max Rady College of Medicine, University of Manitoba, Winnipeg, MB, Canada
| | - Jason Beiko
- Department of Surgery, Section-Neurosurgery, Clincian Investigator Program, Max Rady College of Medicine, Rady Faculty of Health Sciences
| | - Ronald B Cappellani
- Department of Anesthesiology, Perioperative and Pain Medicine, Max Rady College of Medicine, Rady Faculty of Health Sciences
| | - Michael West
- Department of Surgery, Section-Neurosurgery, Clincian Investigator Program, Max Rady College of Medicine, Rady Faculty of Health Sciences
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Narayana S, Gibbs SK, Fulton SP, McGregor AL, Mudigoudar B, Weatherspoon SE, Boop FA, Wheless JW. Clinical Utility of Transcranial Magnetic Stimulation (TMS) in the Presurgical Evaluation of Motor, Speech, and Language Functions in Young Children With Refractory Epilepsy or Brain Tumor: Preliminary Evidence. Front Neurol 2021; 12:650830. [PMID: 34093397 PMCID: PMC8170483 DOI: 10.3389/fneur.2021.650830] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 03/25/2021] [Indexed: 11/25/2022] Open
Abstract
Accurate presurgical mapping of motor, speech, and language cortices, while crucial for neurosurgical planning and minimizing post-operative functional deficits, is challenging in young children with neurological disease. In such children, both invasive (cortical stimulation mapping) and non-invasive functional mapping imaging methods (MEG, fMRI) have limited success, often leading to delayed surgery or adverse post-surgical outcomes. We therefore examined the clinical utility of transcranial magnetic stimulation (TMS) in young children who require functional mapping. In a retrospective chart review of TMS studies performed on children with refractory epilepsy or a brain tumor, at our institution, we identified 47 mapping sessions in 36 children 3 years of age or younger, in whom upper and lower extremity motor mapping was attempted; and 13 children 5–6 years old in whom language mapping, using a naming paradigm, was attempted. The primary hand motor cortex was identified in at least one hemisphere in 33 of 36 patients, and in both hemispheres in 27 children. In 17 children, primary leg motor cortex was also successfully identified. The language cortices in temporal regions were successfully mapped in 11 of 13 patients, and in six of them language cortices in frontal regions were also mapped, with most children (n = 5) showing right hemisphere dominance for expressive language. Ten children had a seizure that was consistent with their clinical semiology during or immediately following TMS, none of which required intervention or impeded completion of mapping. Using TMS, both normal motor, speech, and language developmental patterns and apparent disease induced reorganization were demonstrated in this young cohort. The successful localization of motor, speech, and language cortices in young children improved the understanding of the risk-benefit ratio prior to surgery and facilitated surgical planning aimed at preserving motor, speech, and language functions. Post-operatively, motor function was preserved or improved in nine out of 11 children who underwent surgery, as was language function in all seven children who had surgery for lesions near eloquent cortices. We provide feasibility data that TMS is a safe, reliable, and effective tool to map eloquent cortices in young children.
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Affiliation(s)
- Shalini Narayana
- Division of Pediatric Neurology, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States.,Le Bonheur Children's Hospital, The Neuroscience Institute, Memphis, TN, United States.,Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Savannah K Gibbs
- Le Bonheur Children's Hospital, The Neuroscience Institute, Memphis, TN, United States
| | - Stephen P Fulton
- Division of Pediatric Neurology, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States.,Le Bonheur Children's Hospital, The Neuroscience Institute, Memphis, TN, United States
| | - Amy Lee McGregor
- Division of Pediatric Neurology, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States.,Le Bonheur Children's Hospital, The Neuroscience Institute, Memphis, TN, United States
| | - Basanagoud Mudigoudar
- Division of Pediatric Neurology, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States.,Le Bonheur Children's Hospital, The Neuroscience Institute, Memphis, TN, United States
| | - Sarah E Weatherspoon
- Division of Pediatric Neurology, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States.,Le Bonheur Children's Hospital, The Neuroscience Institute, Memphis, TN, United States
| | - Frederick A Boop
- Le Bonheur Children's Hospital, The Neuroscience Institute, Memphis, TN, United States.,Semmes Murphey Neurologic and Spine Institute, Memphis, TN, United States.,Department of Neurosurgery, University of Tennessee Health Science Center, Memphis, TN, United States
| | - James W Wheless
- Division of Pediatric Neurology, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States.,Le Bonheur Children's Hospital, The Neuroscience Institute, Memphis, TN, United States
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Han Y, Tong X, Wang X, Teng F, Deng Q, Zhou J, Guan Y, Yan Z, Chen L, Luan G, Wang M. A concordance study determining language dominance between navigated transcranial magnetic stimulation and the Wada test in patients with drug-resistant epilepsy. Epilepsy Behav 2021; 117:107711. [PMID: 33636527 DOI: 10.1016/j.yebeh.2020.107711] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 11/18/2020] [Accepted: 12/13/2020] [Indexed: 11/25/2022]
Abstract
OBJECTIVE It remains unclear whether transcranial magnetic stimulation (TMS) can replace the Wada test to determine language hemisphere dominance (HD). Using the Wada test as the gold standard, this study aimed to investigate the accuracy of navigated TMS (nTMS) in determining language HD. METHODS This study enrolled nine right-handed patients with drug-resistant epilepsy. We hypothesized that application of nTMS to language-related areas of the language-dominant hemisphere would induce positive manifestation of language dysfunction (LD). To test our hypothesis, the patients were instructed to perform a visual object-naming task while nTMS was applied to the anterior (e.g., Broca's area) and posterior (e.g., Wernicke's area) regions, which are closely related to language processing. The Wada test result was used as the gold standard, and the diagnostic value of nTMS was assessed using the Kappa consistency test. RESULTS The nTMS-induced LD positive rate for the bilateral anterior language areas (85.7%) was higher than that for the posterior language areas (57.1%). There was high consistency between nTMS stimulation of the left anterior and posterior language areas and the Wada test results for determining language HD. In contrast, the consistency of stimulation of the right anterior and posterior transfer sites was moderate (Kappa value = 0.545, P = 0.171) and low, respectively. For the latter, no statistical calculation was performed because stimulation of the right posterior speech area was negative in all patients compared with the Wada test results. CONCLUSIONS Our findings revealed that using nTMS to stimulate language-related left anterior and posterior areas could predict language HD with high accuracy. When the stimulation performance of these areas is positive, nTMS and the Wada test are equally accurate. Observing only negative performance may indicate that language HD has been transferred to the right side.
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Affiliation(s)
- Yixian Han
- Department of Neurology, SanBo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Xuezhi Tong
- Department of Neurosurgery, SanBo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Xiongfei Wang
- Department of Neurosurgery, SanBo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Fei Teng
- Department of Neurology, SanBo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Qinqin Deng
- Department of Neurology, SanBo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Jian Zhou
- Department of Neurosurgery, SanBo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Yuguang Guan
- Department of Neurosurgery, SanBo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Zhaofen Yan
- Department of Neurology, SanBo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Lingling Chen
- Department of Neurology, SanBo Brain Hospital, Capital Medical University, Beijing 100093, China
| | - Guoming Luan
- Department of Neurosurgery, SanBo Brain Hospital, Capital Medical University, Beijing 100093, China; Beijing Key Laboratory of Epilepsy, Beijing 100093, China; Center of Epilepsy, Beijing Institute for Brain Disorders, Beijing 100093, China.
| | - Mengyang Wang
- Department of Neurology, SanBo Brain Hospital, Capital Medical University, Beijing 100093, China.
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Kim JA, Davis KD. Magnetoencephalography: physics, techniques, and applications in the basic and clinical neurosciences. J Neurophysiol 2021; 125:938-956. [PMID: 33567968 DOI: 10.1152/jn.00530.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Magnetoencephalography (MEG) is a technique used to measure the magnetic fields generated from neuronal activity in the brain. MEG has a high temporal resolution on the order of milliseconds and provides a more direct measure of brain activity when compared with hemodynamic-based neuroimaging methods such as magnetic resonance imaging and positron emission tomography. The current review focuses on basic features of MEG such as the instrumentation and the physics that are integral to the signals that can be measured, and the principles of source localization techniques, particularly the physics of beamforming and the techniques that are used to localize the signal of interest. In addition, we review several metrics that can be used to assess functional coupling in MEG and describe the advantages and disadvantages of each approach. Lastly, we discuss the current and future applications of MEG.
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Affiliation(s)
- Junseok A Kim
- Division of Brain, Imaging and Behaviour, Krembil Brain Institute, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Karen D Davis
- Division of Brain, Imaging and Behaviour, Krembil Brain Institute, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Department of Surgery, University of Toronto, Toronto, Ontario, Canada
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Abstract
Concise history of fascinating magnetoencephalography (MEG) technology and catalog of very selected milestone preclinical and clinical MEG studies are provided as the background. The focus is the societal context defining a journey of MEG to and through clinical practice and formation of the American Clinical MEG Society (ACMEGS). We aspired to provide an objective historic perspective and document contributions of many professionals while focusing on the role of ACMEGS in the growth and maturation of clinical MEG field. The ACMEGS was born (2006) out of inevitability to address two vital issues-fair reimbursement and proper clinical acceptance. A beacon of accountable MEG practice and utilization is now an expanding professional organization with the highest level of competence in practice of clinical MEG and clinical credibility. The ACMEGS facilitated a favorable disposition of insurances toward MEG in the United States by combining the national replication of the grassroots efforts and teaming up with the strategic partners-particularly the American Academy of Neurology (AAN), published two Position Statements (2009 and 2017), the world's only set of MEG Clinical Practice Guidelines (CPGs; 2011) and surveys of clinical MEG practice (2011 and 2020) and use (2020). In addition to the annual ACMEGS Course (2012), we directly engaged MEG practitioners through an Invitational Summit (2019). The Society remains focused on the improvements and expansion of clinical practice, education, clinical training, and constructive engagement of vendors in these issues and pivotal studies toward additional MEG indications. The ACMEGS not only had the critical role in the progress of Clinical MEG in the United States and beyond since 2006 but positioned itself as the field leader in the future.
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The Clinical Utility of Transcranial Magnetic Stimulation in Determining Hemispheric Dominance for Language: A Magnetoencephalography Comparison Study. J Clin Neurophysiol 2020; 37:90-103. [PMID: 32142020 DOI: 10.1097/wnp.0000000000000499] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
PURPOSE Transcranial magnetic stimulation (TMS) has recently emerged as a noninvasive alternative to the intracarotid sodium amytal (Wada) procedure for establishing hemispheric dominance (HD) for language. The accuracy of HD determined by TMS was examined by comparing against the HD derived by magnetoencephalography (MEG), a prominent clinical technique with excellent concordance with the Wada procedure. METHODS Sixty-seven patients (54 patients ≤18 years) underwent language mapping with TMS and MEG as part of clinical epilepsy and tumor presurgical assessment. Language was mapped in MEG during an auditory word recognition paradigm, and a laterality index was calculated using the number of dipoles and their spatial extent in the two hemispheres. Transcranial magnetic stimulation language mapping was performed as patients performed a naming task, and TMS-induced speech disruptions were recorded during 5-Hz TMS applied to anterior and posterior language cortices. Transcranial magnetic stimulation laterality index was estimated using the number and type of speech disruption in the language regions of each hemisphere. RESULTS Transcranial magnetic stimulation and MEG estimates of HD were concordant in 42 (63%) patients, resulting in a sensitivity of 74% and a specificity of 72%. The overall accuracy of TMS was 73%, equivalent to an odds ratio of 7.35. CONCLUSIONS In this first large-scale comparative study in a clinical population, we demonstrate that TMS is a safe and reliable noninvasive tool in determining HD for language. Improving the accuracy of TMS by optimizing TMS parameters and improving task choice will further facilitate the use of TMS to characterize language function, especially in pediatrics.
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12
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Clinical Magnetoencephalography Practice in the United States Ten Years Later: A Survey-Based Reappraisal. J Clin Neurophysiol 2020; 37:592-598. [DOI: 10.1097/wnp.0000000000000693] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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McDowell MM, Ortega Peraza D, Abel TJ. Development and implementation of a novel child life protocol to enhance psychosocial support for pediatric awake craniotomies: technical note. Neurosurg Focus 2020; 48:E5. [PMID: 32006942 DOI: 10.3171/2019.11.focus19774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 11/13/2019] [Indexed: 11/06/2022]
Abstract
Awake craniotomies are a crucial tool for identifying eloquent cortex, but significant limitations frequently related to patient tolerance have limited their applicability in pediatric cases. The authors describe a comprehensive, longitudinal protocol developed in collaboration with a certified child life specialist (CCLS) in order to enhance patient experiences and develop resiliency related to the intraoperative portion of cases. This protocol includes preoperative conditioning, intraoperative support, and postoperative positive reinforcement and debriefing. A unique coping plan is developed for each prospective patient. With appropriate support, awake craniotomy may be applicable in a wider array of preadolescent and adolescent patients than has previously been possible. Future prospective studies are needed to validate this approach.
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Affiliation(s)
- Michael M McDowell
- 1Division of Neurological Surgery, UPMC Children's Hospital of Pittsburgh.,2Department of Neurological Surgery, University of Pittsburgh
| | | | - Taylor J Abel
- 1Division of Neurological Surgery, UPMC Children's Hospital of Pittsburgh.,2Department of Neurological Surgery, University of Pittsburgh.,4Department of Bioengineering, University of Pittsburgh, Pennsylvania
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14
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Structural Imaging and Target Visualization. Stereotact Funct Neurosurg 2020. [DOI: 10.1007/978-3-030-34906-6_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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15
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Lohkamp LN, Mottolese C, Szathmari A, Huguet L, Beuriat PA, Christofori I, Desmurget M, Di Rocco F. Awake brain surgery in children-review of the literature and state-of-the-art. Childs Nerv Syst 2019; 35:2071-2077. [PMID: 31377911 DOI: 10.1007/s00381-019-04279-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 06/25/2019] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Awake brain surgery (ABS) is poorly reported in children as it is considered having limited indications due to age and neuropsychological aspects interfering with its feasibility and psychological outcome. The aim of this article is to review the current state-of-the-art of ABS in children and to offer an objective summary of the published literature on diversified outcome aspects of pediatric awake procedures. METHODS A literature review was performed using the MEDLINE (PubMed) electronic database applying the following MeSH terms to the keyword search within titles and abstracts: "awake brain surgery children," "awake brain surgery pediatric," "awake craniotomy children," "awake craniotomy pediatric," and "awake surgery children." Of the initial 753 results obtained from these keyword searches, a full text screening of 51 publications was performed, ultimately resulting in 18 eligible articles for this review. RESULTS A total of 18 full text articles reporting the results of 50 patients were included in the analysis. Sixteen of the 18 studies were retrospective studies, comprising 7 case series, 9 case reports, and 2 reviews. Eleven studies were conducted from anesthesiological (25 patients) and 7 from neurosurgical (25 patients) departments. Most of the patients underwent ABS for supratentorial lesions (26 patients), followed by epilepsy surgery (16 patients) and deep brain stimulation (DBS) (8 patients). The median age was 15 years (range 8-17 years). Persistent deficits occurred in 6 patients, (12%), corresponding to minor motor palsies (4%) and neuropsychological concerns (8%). An awake procedure was aborted in 2 patients (4%) due to cooperation failure and anxiety, respectively. CONCLUSIONS Despite well-documented beneficial aspects, ABS remains mainly limited to adults. This review confirms a reliable tolerability of ABS in selected children; however, recommendations and guidelines for its standardized implementation in this patient group are pending. Recommendations and guidelines may address diagnostic workup and intra-operative handling besides criteria of eligibility, psychological preparation, and coordinated neuropsychological testing in order to routinely offer ABS to children.
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Affiliation(s)
- Laura-Nanna Lohkamp
- Department of Pediatric Neurosurgery, Hôpital Femme Mère Enfant, Université Claude Bernard Lyon 1, Lyon, France.
| | - Carmine Mottolese
- Department of Pediatric Neurosurgery, Hôpital Femme Mère Enfant, Université Claude Bernard Lyon 1, Lyon, France
| | - Alexandru Szathmari
- Department of Pediatric Neurosurgery, Hôpital Femme Mère Enfant, Université Claude Bernard Lyon 1, Lyon, France
| | - Ludivine Huguet
- Department of Pediatric Neurosurgery, Hôpital Femme Mère Enfant, Université Claude Bernard Lyon 1, Lyon, France
| | - Pierre-Aurelien Beuriat
- Department of Pediatric Neurosurgery, Hôpital Femme Mère Enfant, Université Claude Bernard Lyon 1, Lyon, France.,Center for Cognitive Neuroscience, Lyon, France
| | | | | | - Federico Di Rocco
- Department of Pediatric Neurosurgery, Hôpital Femme Mère Enfant, Université Claude Bernard Lyon 1, Lyon, France.
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16
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Gulati P, Jain P, Lou Smith M, Kerr E, Muthusami P, Shroff M, Whitney R, Carter Snead O, Go C. Reliability and safety of Etomidate speech test in children with drug resistant focal epilepsy. Epilepsy Res 2019; 156:106150. [PMID: 31239182 DOI: 10.1016/j.eplepsyres.2019.106150] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 05/18/2019] [Accepted: 06/09/2019] [Indexed: 11/25/2022]
Abstract
PURPOSE To review our experience with the Etomidate speech test (EST) for lateralizing language in children undergoing epilepsy surgery evaluation METHODS: This retrospective study included children (<18 years) with drug refractory focal epilepsy undergoing EST for bilateral or poorly reliable language representation on functional MRI. Data for consecutive children who underwent EST between January 2013 to June 2017 were reviewed. RESULTS Twenty-one children (mean age at EST, 13.1 ± 4.4 years) were studied, with 19-right hemispheric and 20 left hemispheric injections. Six patients had neurological co-morbidities. Duration of ipsilateral EEG slowing was sufficient for speech testing in all children with a single bolus of Etomidate per carotid artery. Language was lateralized to one hemisphere in 17 (80.9%) and bilateral in two cases. EST was unsuccessful in two patients because of diffuse EEG slowing. Contralateral transient frontal EEG slowing was seen in 14 (73.7%) cases. EST was well tolerated in all the patients. CONCLUSIONS The EST was found to be successful and safe in lateralizing language in most of our drug refractory pediatric epilepsy cohort.
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Affiliation(s)
- Pratima Gulati
- Pratima Gulati, Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, Toronto, Ontario, M5G1X8, Canada.
| | - Puneet Jain
- Pratima Gulati, Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, Toronto, Ontario, M5G1X8, Canada; Division of Pediatric Neurology, Department of Pediatrics, BL Kapur (BLK) Super Speciality Hospital, Pusa Road, New Delhi 110005 India.
| | - Mary Lou Smith
- Mary Lou Smith, Division of Neurology, The Hospital for Sick Children, Department of Psychology, University of Toronto, Ontario, M5G1X8, Canada.
| | - Elizabeth Kerr
- Division of Neurology, Department of Psychology, University of Toronto, M5G1X8, Ontario, Canada.
| | - Prakash Muthusami
- Neuroradiology, Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, M5G1X8, Canada.
| | - Manohar Shroff
- Neuroradiology, Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, Ontario, M5G1X8, Canada.
| | - Robyn Whitney
- Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, Toronto, Ontario, M5G1X8, Canada.
| | - O Carter Snead
- Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, Toronto, Ontario, M5G1X8, Canada.
| | - Cristina Go
- Division of Neurology, Department of Pediatrics, The Hospital for Sick Children, Toronto, Ontario, M5G1X8, Canada.
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17
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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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18
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Language lateralisation measured across linguistic and national boundaries. Cortex 2019; 111:134-147. [DOI: 10.1016/j.cortex.2018.10.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 07/25/2018] [Accepted: 10/22/2018] [Indexed: 11/19/2022]
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19
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Tierney TM, Holmes N, Meyer SS, Boto E, Roberts G, Leggett J, Buck S, Duque-Muñoz L, Litvak V, Bestmann S, Baldeweg T, Bowtell R, Brookes MJ, Barnes GR. Cognitive neuroscience using wearable magnetometer arrays: Non-invasive assessment of language function. Neuroimage 2018; 181:513-520. [PMID: 30016678 PMCID: PMC6150946 DOI: 10.1016/j.neuroimage.2018.07.035] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 06/10/2018] [Accepted: 07/13/2018] [Indexed: 11/30/2022] Open
Abstract
Recent work has demonstrated that Optically Pumped Magnetometers (OPMs) can be utilised to create a wearable Magnetoencephalography (MEG) system that is motion robust. In this study, we use this system to map eloquent cortex using a clinically validated language lateralisation paradigm (covert verb generation: 120 trials, ∼10 min total duration) in healthy adults (n = 3). We show that it is possible to lateralise and localise language function on a case by case basis using this system. Specifically, we show that at a sensor and source level we can reliably detect a lateralising beta band (15-30 Hz) desynchronization in all subjects. This is the first study of human cognition using OPMs and not only highlights this technology's utility as tool for (developmental) cognitive neuroscience but also its potential to contribute to surgical planning via mapping of eloquent cortex, especially in young children.
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Affiliation(s)
- Tim M Tierney
- Wellcome Centre for Human Neuroimaging, UCL Institute of Neurology, London, WC1N 3BG, UK.
| | - Niall Holmes
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Sofie S Meyer
- Wellcome Centre for Human Neuroimaging, UCL Institute of Neurology, London, WC1N 3BG, UK; UCL Institute of Cognitive Neuroscience, University College London, London, WC1N 3AZ, UK
| | - Elena Boto
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Gillian Roberts
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - James Leggett
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Sarah Buck
- Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, WC1N 1EH, UK
| | - Leonardo Duque-Muñoz
- Departamento de Ingeniería Electrónica, Universidad de Antioquia, Medellín, Colombia; AE&C Research Group, Insituto Tecnológico Metropolitano, Medellín, Colombia
| | - Vladimir Litvak
- Wellcome Centre for Human Neuroimaging, UCL Institute of Neurology, London, WC1N 3BG, UK
| | - Sven Bestmann
- Wellcome Centre for Human Neuroimaging, UCL Institute of Neurology, London, WC1N 3BG, UK
| | - Torsten Baldeweg
- Developmental Neurosciences Programme, UCL Great Ormond Street Institute of Child Health, London, WC1N 1EH, UK
| | - Richard Bowtell
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Matthew J Brookes
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Gareth R Barnes
- Wellcome Centre for Human Neuroimaging, UCL Institute of Neurology, London, WC1N 3BG, UK
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20
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Abstract
Focal epilepsy originating from the insular cortex is rare. One reason is the small amount of cortical tissue compared with other lobes of the brain. However, the incidence of insular epilepsy might be underestimated because of diagnostic difficulties. The semiology and the surface EEG are often not meaningful or even misleading, and elaborated imaging might be necessary. The close connections of the insular cortex with other potentially epileptogenic areas, such as the temporal lobe or frontal/central cortex, is increasingly recognized as possible reason for failure of epilepsy surgery for temporal or extratemporal seizures. Therefore, some centers consider invasive EEG recording of the insular cortex not only in case of insular epilepsy but also in other focal epilepsies with nonconclusive results from the presurgical work-up. The surgical approach to and resection of insular cortex is challenging because of its deep location and proximity to highly eloquent brain structures. Over the last decades, technical adjuncts like navigation tools, electrophysiological monitoring and intraoperative imaging have improved the outcome after surgery. Nevertheless, there is still a considerable rate of postoperative transient or permanent deficits, in some cases as unavoidable and calculated deficits. In most of the recent series, seizure outcome was favorable and comparable with extratemporal epilepsy surgery or even better. Up to now, the data volume concerning long-term follow-up is limited. This review focusses on the surgical challenges of resections to treat insular epilepsy, on prognostic factors concerning seizure outcome, on postoperative deficits and complications. Moreover, less invasive surgical techniques to treat epilepsy in this highly eloquent area are summarized.
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21
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Hari R, Baillet S, Barnes G, Burgess R, Forss N, Gross J, Hämäläinen M, Jensen O, Kakigi R, Mauguière F, Nakasato N, Puce A, Romani GL, Schnitzler A, Taulu S. IFCN-endorsed practical guidelines for clinical magnetoencephalography (MEG). Clin Neurophysiol 2018; 129:1720-1747. [PMID: 29724661 PMCID: PMC6045462 DOI: 10.1016/j.clinph.2018.03.042] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 03/18/2018] [Accepted: 03/24/2018] [Indexed: 12/22/2022]
Abstract
Magnetoencephalography (MEG) records weak magnetic fields outside the human head and thereby provides millisecond-accurate information about neuronal currents supporting human brain function. MEG and electroencephalography (EEG) are closely related complementary methods and should be interpreted together whenever possible. This manuscript covers the basic physical and physiological principles of MEG and discusses the main aspects of state-of-the-art MEG data analysis. We provide guidelines for best practices of patient preparation, stimulus presentation, MEG data collection and analysis, as well as for MEG interpretation in routine clinical examinations. In 2017, about 200 whole-scalp MEG devices were in operation worldwide, many of them located in clinical environments. Yet, the established clinical indications for MEG examinations remain few, mainly restricted to the diagnostics of epilepsy and to preoperative functional evaluation of neurosurgical patients. We are confident that the extensive ongoing basic MEG research indicates potential for the evaluation of neurological and psychiatric syndromes, developmental disorders, and the integrity of cortical brain networks after stroke. Basic and clinical research is, thus, paving way for new clinical applications to be identified by an increasing number of practitioners of MEG.
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Affiliation(s)
- Riitta Hari
- Department of Art, Aalto University, Helsinki, Finland.
| | - Sylvain Baillet
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Gareth Barnes
- Wellcome Centre for Human Neuroimaging, University College of London, London, UK
| | - Richard Burgess
- Epilepsy Center, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Nina Forss
- Clinical Neuroscience, Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Joachim Gross
- Centre for Cognitive Neuroimaging, University of Glasgow, Glasgow, UK; Institute for Biomagnetism and Biosignalanalysis, University of Muenster, Germany
| | - Matti Hämäläinen
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA; Harvard Medical School, Boston, MA, USA; NatMEG, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Ole Jensen
- Centre for Human Brain Health, University of Birmingham, Birmingham, UK
| | - Ryusuke Kakigi
- Department of Integrative Physiology, National Institute of Physiological Sciences, Okazaki, Japan
| | - François Mauguière
- Department of Functional Neurology and Epileptology, Neurological Hospital & University of Lyon, Lyon, France
| | | | - Aina Puce
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA
| | - Gian-Luca Romani
- Department of Neuroscience, Imaging and Clinical Sciences, Università degli Studi G. D'Annunzio, Chieti, Italy
| | - Alfons Schnitzler
- Institute of Clinical Neuroscience and Medical Psychology, and Department of Neurology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Samu Taulu
- Institute for Learning & Brain Sciences, University of Washington, Seattle, WA, USA; Department of Physics, University of Washington, Seattle, WA, USA
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22
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Functional brain mapping: overview of techniques and their application to neurosurgery. Neurosurg Rev 2018; 42:639-647. [DOI: 10.1007/s10143-018-1007-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 06/25/2018] [Accepted: 07/06/2018] [Indexed: 10/28/2022]
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23
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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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Cabrera OS, Lehéricy S, Masson V, Samson S, Dupont S. Adapting a memory fMRI research protocol in clinical routine: Feasibility and results. Epilepsy Behav 2018; 81:49-54. [PMID: 29477011 DOI: 10.1016/j.yebeh.2017.11.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 11/10/2017] [Accepted: 11/19/2017] [Indexed: 10/18/2022]
Abstract
OBJECTIVE The objective of this study was to test the reliability of functional magnetic resonance imaging (fMRI) evaluation of memory function in clinical practice to predict postoperative memory decline in patients with refractory medial temporal lobe epilepsy (MTLE) candidate to surgery. METHODS Twenty-six consecutive patients with MTLE who underwent a complete presurgical evaluation were included. All patients underwent fMRI memory study and complete neuropsychological assessment. Lesions consisted in hippocampal sclerosis in 18 patients (12 right and 6 left), dysembryoplastic neuroepithelial tumor (DNET) in 5 cases (4 right, 1 left), epidermoid cyst in one patient (right). Two patients had no lesion (2 left). RESULTS Nineteen patients (73%) underwent surgery. The other seven patients (27%) declined surgery, mainly because of the risk of memory deficit. The fMRI procedure correctly predicted both verbal and nonverbal memory postoperative outcome in 13 of the patients (72%), failed to predict a postoperative memory worsening in only two patients (12%), and predicted worsening in three patients (17%) that remained stable (versus 44%, 39%, and 17% with the sole neuropsychological testing). The reliability of the fMRI procedure was not influenced by the type of lesion, the side of the epileptic focus, or the type of preoperative memory profile (typical or atypical). SIGNIFICANCE Appearing as a valuable clinical tool to predict postoperative memory outcome, fMRI may add information over and above other available tests.
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Affiliation(s)
- Ovidio Solano Cabrera
- Epilepsy unit, AP-HP Groupe hospitalier Pitié-Salpêtrière-Charles Foix, F-75013 Paris, France; Epilepsy Clinic, Neurology department, Social Security Salvadoran Institute, San Salvador, El Salvador
| | - Stéphane Lehéricy
- Neuroradiology unit, AP-HP Groupe hospitalier Pitié-Salpêtrière-Charles Foix, F-75013 Paris, France; Inserm U 1127, CNRS UMR 7225, UMR S 1127, Institut du Cerveau et de la Moelle épinière - ICM, Centre de Neuroimagerie de Recherche - CENIR, F-75013 Paris, France; Sorbonne University, UPMC Univ. Paris 06, F-75005 Paris, France
| | - Véronique Masson
- Epilepsy unit, AP-HP Groupe hospitalier Pitié-Salpêtrière-Charles Foix, F-75013 Paris, France
| | - Séverine Samson
- Laboratoire PSITEC (EA 4072), Université de Lille, F-59000 Lille, France
| | - Sophie Dupont
- Epilepsy unit, AP-HP Groupe hospitalier Pitié-Salpêtrière-Charles Foix, F-75013 Paris, France; Inserm U 1127, CNRS UMR 7225, UMR S 1127, Institut du Cerveau et de la Moelle épinière - ICM, Centre de Neuroimagerie de Recherche - CENIR, F-75013 Paris, France; Sorbonne University, UPMC Univ. Paris 06, F-75005 Paris, France; Rehabilitation unit, AP-HP Groupe hospitalier Pitié-Salpêtrière-Charles Foix, F-75013 Paris, France.
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25
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Dinga S, Wu D, Huang S, Wu C, Wang X, Shi J, Hu Y, Liang C, Zhang F, Lu M, Leiken K, Xiang J. Neuromagnetic correlates of audiovisual word processing in the developing brain. Int J Psychophysiol 2018; 128:7-21. [PMID: 29580903 DOI: 10.1016/j.ijpsycho.2018.03.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 03/01/2018] [Accepted: 03/21/2018] [Indexed: 11/25/2022]
Abstract
The brain undergoes enormous changes during childhood. Little is known about how the brain develops to serve word processing. The objective of the present study was to investigate the maturational changes of word processing in children and adolescents using magnetoencephalography (MEG). Responses to a word processing task were investigated in sixty healthy participants. Each participant was presented with simultaneous visual and auditory word pairs in "match" and "mismatch" conditions. The patterns of neuromagnetic activation from MEG recordings were analyzed at both sensor and source levels. Topography and source imaging revealed that word processing transitioned from bilateral connections to unilateral connections as age increased from 6 to 17 years old. Correlation analyses of language networks revealed that the path length of word processing networks negatively correlated with age (r = -0.833, p < 0.0001), while the connection strength (r = 0.541, p < 0.01) and the clustering coefficient (r = 0.705, p < 0.001) of word processing networks were positively correlated with age. In addition, males had more visual connections, whereas females had more auditory connections. The correlations between gender and path length, gender and connection strength, and gender and clustering coefficient demonstrated a developmental trend without reaching statistical significance. The results indicate that the developmental trajectory of word processing is gender specific. Since the neuromagnetic signatures of these gender-specific paths to adult word processing were determined using non-invasive, objective, and quantitative methods, the results may play a key role in understanding language impairments in pediatric patients in the future.
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Affiliation(s)
- Samantha Dinga
- Psychology Department, University of Rochester, 500 Joseph C Wilson Blvd, Rochester, NY 14627, USA; MEG Center, Department of Neurology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45220, USA
| | - Di Wu
- Department of Neurology, Nanjing Brain Hospital, Nanjing Medical University, Jiangsu, China
| | - Shuyang Huang
- Department of Neurology, Nanjing Brain Hospital, Nanjing Medical University, Jiangsu, China
| | - Caiyun Wu
- Department of Neurology, Nanjing Brain Hospital, Nanjing Medical University, Jiangsu, China
| | - Xiaoshan Wang
- Department of Neurology, Nanjing Brain Hospital, Nanjing Medical University, Jiangsu, China
| | - Jingping Shi
- Department of Neurology, Nanjing Brain Hospital, Nanjing Medical University, Jiangsu, China
| | - Yue Hu
- Department of Neurology, Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Chun Liang
- Department of Communication Sciences and Disorders, University of Cincinnati, Cincinnati, OH, USA
| | - Fawen Zhang
- Department of Communication Sciences and Disorders, University of Cincinnati, Cincinnati, OH, USA
| | - Meng Lu
- College of Information Science and Engineering, Northeastern University, Shenyang, China
| | - Kimberly Leiken
- MEG Center, Department of Neurology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45220, USA
| | - Jing Xiang
- MEG Center, Department of Neurology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45220, USA.
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Babajani-Feremi A, Holder CM, Narayana S, Fulton SP, Choudhri AF, Boop FA, Wheless JW. Predicting postoperative language outcome using presurgical fMRI, MEG, TMS, and high gamma ECoG. Clin Neurophysiol 2018; 129:560-571. [PMID: 29414401 DOI: 10.1016/j.clinph.2017.12.031] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 11/17/2017] [Accepted: 12/05/2017] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To predict the postoperative language outcome using the support vector regression (SVR) and results of multimodal presurgical language mapping. METHODS Eleven patients with epilepsy received presurgical language mapping using functional MRI (fMRI), magnetoencephalography (MEG), transcranial magnetic stimulation (TMS), and high-gamma electrocorticography (hgECoG), as well as pre- and postoperative neuropsychological evaluation of language. We constructed 15 (24-1) SVR models by considering the extent of resected language areas identified by all subsets of four modalities as input feature vector and the postoperative language outcome as output. We trained and cross-validated SVR models, and compared the cross-validation (CV) errors of all models for prediction of language outcome. RESULTS Seven patients had some level of postoperative language decline and two of them had significant postoperative decline in naming. Some parts of language areas identified by four modalities were resected in these patients. We found that an SVR model consisting of fMRI, MEG, and hgECoG provided minimum CV error, although an SVR model consisting of fMRI and MEG was the optimal model that facilitated the best trade-off between model complexity and prediction accuracy. CONCLUSIONS A multimodal SVR can be used to predict the language outcome. SIGNIFICANCE The developed multimodal SVR models in this study can be utilized to calculate the language outcomes of different resection plans prior to surgery and select the optimal surgical plan.
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Affiliation(s)
- Abbas Babajani-Feremi
- University of Tennessee Health Science Center, Department of Pediatrics and Department of Anatomy and Neurobiology, Le Bonheur Children's Hospital, Neuroscience Institute, Memphis, TN, USA.
| | - Christen M Holder
- University of Tennessee Health Science Center, Department of Pediatrics, Le Bonheur Children's Hospital, Neuroscience Institute, Memphis, TN, USA
| | - Shalini Narayana
- University of Tennessee Health Science Center, Department of Pediatrics and Department of Anatomy and Neurobiology, Le Bonheur Children's Hospital, Neuroscience Institute, Memphis, TN, USA
| | - Stephen P Fulton
- University of Tennessee Health Science Center, Department of Pediatrics, Le Bonheur Children's Hospital, Neuroscience Institute, Memphis, TN, USA
| | - Asim F Choudhri
- University of Tennessee Health Science Center, Department of Pediatrics, Le Bonheur Children's Hospital, Neuroscience Institute, Memphis, TN, USA
| | - Frederick A Boop
- University of Tennessee Health Science Center, Department of Pediatrics, Le Bonheur Children's Hospital, Neuroscience Institute, Memphis, TN, USA
| | - James W Wheless
- University of Tennessee Health Science Center, Department of Pediatrics, Le Bonheur Children's Hospital, Neuroscience Institute, Memphis, TN, USA
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Kemp S, Prendergast G, Karapanagiotidis T, Baker G, Kelly TP, Patankar T, Keller SS. Concordance between the Wada test and neuroimaging lateralization: Influence of imaging modality (fMRI and MEG) and patient experience. Epilepsy Behav 2018; 78:155-160. [PMID: 29245083 DOI: 10.1016/j.yebeh.2017.09.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 09/26/2017] [Accepted: 09/28/2017] [Indexed: 11/24/2022]
Abstract
The Wada test remains the traditional test for lateralizing language and memory function prior to epilepsy surgery. Functional imaging, particularly functional MRI (fMRI), has made progress in the language domain, but less so in the memory domain. Magnetoencephalography (MEG) has received less research attention, but shows promise, particularly for language lateralization. We recruited a consecutive sample of 19 patients with epilepsy who had completed presurgical work-up, including the Wada test, and compared fMRI (memory) and MEG (language and memory) with Wada test results. The main research question was the concordance between Wada and these two imaging techniques as preepilepsy surgery investigations. We were also interested in the acceptability of the three techniques to patients. Concordance rates (N=16) were nonsignificant (Cohen's Kappa) between fMRI and Wada test (memory) and between MEG and Wada test (memory and language). The Wada test was a well-established protocol used at several epilepsy surgery centers in the UK. Patients generally found the Wada test an odd, but not aversive procedure. Sixteen (84%) patients who were scanned reported some level of obtundation in MEG. We present these discordant findings in support of the position that functional imaging and the Wada test are distinctive procedures, with little in the way of overlapping mechanisms, and that patient's experience should be taken into account when procedures are selected and offered to them.
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Affiliation(s)
- Steven Kemp
- Department of Clinical and Health Psychology, St James's University Hospital, Leeds, UK.
| | | | | | - Gus Baker
- University of Liverpool, UK/The Walton Centre NHS Foundation Trust, Liverpool, UK
| | | | | | - Simon S Keller
- University of Liverpool, UK/The Walton Centre NHS Foundation Trust, Liverpool, UK; Department of Neuroradiology, The Walton Centre NHS Foundation Trust, Liverpool, UK
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Chou N, Serafini S, Muh CR. Cortical Language Areas and Plasticity in Pediatric Patients With Epilepsy: A Review. Pediatr Neurol 2018; 78:3-12. [PMID: 29191650 DOI: 10.1016/j.pediatrneurol.2017.10.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 08/28/2017] [Accepted: 10/02/2017] [Indexed: 12/12/2022]
Abstract
Chronic injury to the brain from seizure activity is associated with decreased language skills in pediatric patients, as measured on neuropsychological tests for language function and academic achievement. This makes the study of language in patients with epilepsy clinically necessary. Functional magnetic resonance imaging and direct electrical cortical stimulation have been used to evaluate aspects of cortical language processing in healthy adults and in adults with epilepsy or other neurological insults. Results of these studies help to locate cortical language areas that are involved with modality-specific language processing (visual naming, auditory naming, sentence-completion, and repetition) and the neuroplasticity of language areas in the setting of neurological injury and reorganization. A better understanding of language processing contributes to a more efficient and efficacious electrical cortical stimulation mapping of language areas for patients with intractable epilepsy who are undergoing preresection evaluation. Most of the current literature on localization and reorganization of cortical language areas in the setting of epilepsy concerns the adult patient population, whereas the literature on pediatric patients is substantially lacking in comparison. This article reviews the conclusions drawn thus far from Wada, magnetoencephalography, functional magnetic resonance imaging, and electrical cortical stimulation language studies on types of language reorganization seen in pediatric patients with intractable temporal lobe epilepsy and the clinical factors associated with reorganization, and proposes future directions of research to further the academic and clinical understanding of language processing in pediatric patients.
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Affiliation(s)
- Naomi Chou
- Duke University School of Medicine, Durham, North Carolina
| | - Sandra Serafini
- Department of Neurosurgery, Duke University Medical Center, Durham, North Carolina
| | - Carrie R Muh
- Department of Neurosurgery, Duke University Medical Center, Durham, North Carolina.
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Ogawa H, Hiroshima S, Kamada K. Left hippocampectomy in an epilepsy patient with right hemisphere language dominance. COGENT MEDICINE 2017. [DOI: 10.1080/2331205x.2017.1364029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Affiliation(s)
- Hiroshi Ogawa
- Department of Neurosurgery, Asahikawa Medical University, 2-1, Midorigaoka-Higashi, Asahikawa, Hokkaido, 078-8510, Japan
| | - Satoru Hiroshima
- Department of Neurosurgery, Asahikawa Medical University, 2-1, Midorigaoka-Higashi, Asahikawa, Hokkaido, 078-8510, Japan
| | - Kyousuke Kamada
- Department of Neurosurgery, Asahikawa Medical University, 2-1, Midorigaoka-Higashi, Asahikawa, Hokkaido, 078-8510, Japan
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Abstract
Intracranial EEG (iEEG) recordings are widely used for the work up of pharmacoresistant epilepsy. Different iEEG recording techniques namely subdural grids, strips, depth electrodes and stereoencephalography (SEEG) are available with distinct limitations and advantages. Epilepsy centres mastering multiple techniques apply them in an individualised patient approach. These tools are used to map the seizure onset zone which is pivotal in approximating the epileptogenic zone, i.e. the zone which is indispensable for the generation of seizures and when resected will render the patient seizure free. Besides, the implanted electrodes can be used to define eloquent cortex through direct cortical stimulation. Different clinical scenarios exist which favour one iEEG recording technique over the other. Proximity of the presumed epileptogenic zone to eloquent cortex, for example, is a clinical scenario which may favour grid electrodes over SEEG. We here review the indication for iEEG for the work-up of patients suffering from pharmacoresistant epilepsy. In addition, we provide a description of the recording techniques focussing on the main techniques used: grid electrodes, depth electrodes and stereoencephalography. We then outline different clinical scenarios and the preferred technical approach for intracranial recordings in these scenarios. Finally, we highlight which advances have been made in the field of iEEG and which advances are in the pipeline waiting to be established for clinical use. This review provides the clinician with an update on the diagnostic use of intracranial EEG for epilepsy surgery and thus aids in understanding patient selection for this technique which may ultimately improve referral patterns.
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Alonso F, Sweet J, Miller J. Speech mapping using depth electrodes: The “electric Wada”. Clin Neurol Neurosurg 2016; 144:88-90. [DOI: 10.1016/j.clineuro.2016.03.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 03/13/2016] [Accepted: 03/18/2016] [Indexed: 10/22/2022]
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Pirmoradi M, Jemel B, Gallagher A, Tremblay J, D’Hondt F, Nguyen DK, Béland R, Lassonde M. Verbal memory and verbal fluency tasks used for language localization and lateralization during magnetoencephalography. Epilepsy Res 2016; 119:1-9. [DOI: 10.1016/j.eplepsyres.2015.11.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 10/02/2015] [Accepted: 11/13/2015] [Indexed: 11/27/2022]
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Babajani-Feremi A, Narayana S, Rezaie R, Choudhri AF, Fulton SP, Boop FA, Wheless JW, Papanicolaou AC. Language mapping using high gamma electrocorticography, fMRI, and TMS versus electrocortical stimulation. Clin Neurophysiol 2015; 127:1822-36. [PMID: 26679420 DOI: 10.1016/j.clinph.2015.11.017] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 10/30/2015] [Accepted: 11/19/2015] [Indexed: 11/27/2022]
Abstract
OBJECTIVE The aim of the present study was to compare localization of the language cortex using cortical stimulation mapping (CSM), high gamma electrocorticography (hgECoG), functional magnetic resonance imaging (fMRI), and transcranial magnetic stimulation (TMS). METHODS Language mapping using CSM, hgECoG, fMRI, and TMS were compared in nine patients with epilepsy. Considering CSM as reference, we compared language mapping approaches based on hgECoG, fMRI, and TMS using their sensitivity, specificity, and the results of receiver operating characteristic (ROC) analyses. RESULTS Our results show that areas involved in language processing can be identified by hgECoG, fMRI, and TMS. The average sensitivity/specificity of hgECoG, fMRI, and TMS across all patients was 100%/85%, 50%/80%, and 67%/66%, respectively. The average area under the ROC curve of hgECoG, fMRI, and TMS across CSM-positive patients was 0.98, 0.76, and 0.68, respectively. CONCLUSIONS There is considerable concordance between CSM, hgECoG, fMRI, and TMS language mapping. Our results reveal that hgECoG, fMRI, and TMS are valuable tools for presurgical language mapping. SIGNIFICANCE Language mapping on the basis of hgECoG, fMRI, and TMS can provide important additional information, therefore, these methods can be used in conjunction with CSM or as an alternative, when the latter is deemed impractical.
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Affiliation(s)
- Abbas Babajani-Feremi
- Department of Pediatrics, Division of Clinical Neurosciences, University of Tennessee Health Science Center, Memphis, TN, USA; Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, TN, USA; Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA.
| | - Shalini Narayana
- Department of Pediatrics, Division of Clinical Neurosciences, University of Tennessee Health Science Center, Memphis, TN, USA; Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, TN, USA; Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Roozbeh Rezaie
- Department of Pediatrics, Division of Clinical Neurosciences, University of Tennessee Health Science Center, Memphis, TN, USA; Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, TN, USA
| | - Asim F Choudhri
- Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, TN, USA; Department of Radiology, University of Tennessee Health Science Center, Memphis, TN, USA; Department of Neurosurgery, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Stephen P Fulton
- Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, TN, USA; Department of Pediatrics, Division of Pediatric Neurology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Frederick A Boop
- Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, TN, USA; Department of Neurosurgery, University of Tennessee Health Science Center, Memphis, TN, USA
| | - James W Wheless
- Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, TN, USA; Department of Pediatrics, Division of Pediatric Neurology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Andrew C Papanicolaou
- Department of Pediatrics, Division of Clinical Neurosciences, University of Tennessee Health Science Center, Memphis, TN, USA; Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, TN, USA; Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
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Variation in the topography of the speech production cortex verified by cortical stimulation and high gamma activity. Neuroreport 2015; 25:1411-7. [PMID: 25371284 PMCID: PMC4232293 DOI: 10.1097/wnr.0000000000000276] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Supplemental Digital Content is available in the text. In this study, we have addressed the question of functional brain reorganization for language in the presence and absence of anatomical lesions in two patients with epilepsy using cortical stimulation mapping and high gamma (HG) activity in subdural grid recordings. In both, the expressive language cortex was defined as the cortical patch below the electrode(s) that when stimulated resulted in speech arrest, and during speech expression tasks generated HG activity. This patch fell within the borders of Broca’s area, as defined anatomically, in the case of the patient with a lesion, but outside that area in the other, lesion-free patient. Such results highlight the necessity for presurgical language mapping in all cases of surgery involving the language-dominant hemisphere and suggest that HG activity during expressive language tasks can be informative and helpful in conjunction with cortical stimulation mapping for expressive language mapping.
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Choudhri AF, Patel RM, Siddiqui A, Whitehead MT, Wheless JW. Cortical Activation Through Passive-Motion Functional MRI. AJNR Am J Neuroradiol 2015; 36:1675-81. [PMID: 26228890 DOI: 10.3174/ajnr.a4345] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 02/13/2015] [Indexed: 12/24/2022]
Abstract
BACKGROUND AND PURPOSE Functional brain mapping is an important technique for neurosurgical planning, particularly for patients with tumors or epilepsy; however, mapping has traditionally involved invasive techniques. Existing noninvasive techniques require patient compliance and may not be suitable for young children. We performed a retrospective review of our experience with passive-motion functional MR imaging in anesthetized patients to determine the diagnostic yield of this technique. MATERIALS AND METHODS A retrospective review of patients undergoing passive-motion fMRI under general anesthesia at a single institution over a 2.5-year period was performed. Clinical records were evaluated to determine the indication for fMRI, the ability to detect cortical activation, and, if present, the location of cortical activation. RESULTS We identified 62 studies in 56 patients in this time period. The most common indication for fMRI was epilepsy/seizures. Passive-motion fMRI identified upper-extremity cortical activation in 105 of 119 (88%) limbs evaluated, of which 90 (86%) activations were in an orthotopic location. Lower-extremity cortical activation was identified in 86 of 118 (73%) limbs evaluated, of which 73 (85%) activations were in an orthotopic location. CONCLUSIONS Passive-motion fMRI was successful in identifying cortical activation in most of the patients. This tool can be implemented easily and can aid in surgical planning for children with tumors or candidates for epilepsy surgery, particularly those who may be too young to comply with existing noninvasive functional measures.
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Affiliation(s)
- A F Choudhri
- From the Departments of Radiology (A.F.C., A.S., M.T.W.) Neurosurgery (A.F.C.) Le Bonheur Neuroscience Institute (A.F.C., A.S., M.T.W., J.W.W.), Le Bonheur Children's Hospital, Memphis, Tennessee
| | - R M Patel
- College of Medicine (R.M.P.), University of Tennessee Health Science Center, Memphis, Tennessee
| | - A Siddiqui
- From the Departments of Radiology (A.F.C., A.S., M.T.W.) Le Bonheur Neuroscience Institute (A.F.C., A.S., M.T.W., J.W.W.), Le Bonheur Children's Hospital, Memphis, Tennessee
| | - M T Whitehead
- From the Departments of Radiology (A.F.C., A.S., M.T.W.) Le Bonheur Neuroscience Institute (A.F.C., A.S., M.T.W., J.W.W.), Le Bonheur Children's Hospital, Memphis, Tennessee Department of Radiology (M.T.W.), Children's National Medical Center, Washington, DC
| | - J W Wheless
- Pediatrics (J.W.W.) Le Bonheur Neuroscience Institute (A.F.C., A.S., M.T.W., J.W.W.), Le Bonheur Children's Hospital, Memphis, Tennessee
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Beimer NJ, Buchtel HA, Glynn SM. One center's experience with complications during the Wada test. Epilepsia 2015; 56:e110-3. [DOI: 10.1111/epi.13046] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/30/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Nicholas J. Beimer
- Department of Neurology; University of Michigan; Ann Arbor Michigan U.S.A
| | - Henry A. Buchtel
- Department of Psychiatry; University of Michigan; Ann Arbor Michigan U.S.A
- Neuropsychology Section; VA Ann Arbor; Ann Arbor Michigan U.S.A
| | - Simon M. Glynn
- Department of Neurology; University of Michigan; Ann Arbor Michigan U.S.A
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Bagić A. Look back to leap forward: The emerging new role of magnetoencephalography (MEG) in nonlesional epilepsy. Clin Neurophysiol 2015; 127:60-66. [PMID: 26055337 DOI: 10.1016/j.clinph.2015.05.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 05/02/2015] [Accepted: 05/08/2015] [Indexed: 11/25/2022]
Abstract
This review considers accumulating evidence for a new role of MEG/MSI in increasing the diagnostic yield of supposedly negative MRIs, and suggests changes in the use of MEG/MSI in presurgical epilepsy evaluations. Specific alterations in practice protocols for both the MEG practitioner (i.e. physician magnetoencephalographer) and MEG user (i.e. referring physician) are proposed that should further enhance the overall value of MEG/MSI. Although advances in MEG analysis methods will likely become increasingly assisted by computers, interpretive competency and prudent clinical judgment remain irreplaceable.
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Affiliation(s)
- Anto Bagić
- University of Pittsburgh Comprehensive Epilepsy Center (UPCEC), UPMC MEG Epilepsy Program, Department of Neurology, University of Pittsburgh Medical School, Suite 811, Kaufmann Medical Building, 3471 Fifth Ave, Pittsburgh, PA 15213, USA.
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Abstract
Awake craniotomy is the only established way to assess patients' language functions intraoperatively and to contribute to their preservation, if necessary. Recent guidelines have enabled the approach to be used widely, effectively, and safely. Non-invasive brain functional imaging techniques, including functional magnetic resonance imaging and diffusion tensor imaging, have been used preoperatively to identify brain functional regions corresponding to language, and their accuracy has increased year by year. In addition, the use of neuronavigation that incorporates this preoperative information has made it possible to identify the positional relationships between the lesion and functional regions involved in language, conduct functional brain mapping in the awake state with electrical stimulation, and intraoperatively assess nerve function in real time when resecting the lesion. This article outlines the history of awake craniotomy, the current state of pre- and intraoperative evaluation of language function, and the clinical usefulness of such functional evaluation. When evaluating patients' language functions during awake craniotomy, given the various intraoperative stresses involved, it is necessary to carefully select the tasks to be undertaken, quickly perform all examinations, and promptly evaluate the results. As language functions involve both input and output, they are strongly affected by patients' preoperative cognitive function, degree of intraoperative wakefulness and fatigue, the ability to produce verbal articulations and utterances, as well as perform synergic movement. Therefore, it is essential to appropriately assess the reproducibility of language function evaluation using awake craniotomy techniques.
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Affiliation(s)
- Aya Kanno
- Department of Neurosurgery, Sapporo Medical University School of Medicine
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Narayana S, Rezaie R, McAfee SS, Choudhri AF, Babajani-Feremi A, Fulton S, Boop FA, Wheless JW, Papanicolaou AC. Assessing motor function in young children with transcranial magnetic stimulation. Pediatr Neurol 2015; 52:94-103. [PMID: 25439485 DOI: 10.1016/j.pediatrneurol.2014.08.031] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 08/28/2014] [Accepted: 08/31/2014] [Indexed: 11/18/2022]
Abstract
OBJECTIVE Accurate noninvasive assessment of motor function using functional MRI (fMRI) and magnetoencephalography (MEG) is a challenge in patients who are very young or who are developmentally delayed. In such cases, passive mapping of the sensorimotor cortex is performed under sedation. We examined the feasibility of using transcranial magnetic stimulation (TMS) as a motor mapping tool in awake children younger than 3 years of age. METHODS Six children underwent motor mapping with TMS while awake as well as passive sensorimotor mapping under conscious sedation with MEG during tactile stimulation (n = 5) and fMRI during passive hand movements (n = 4). RESULTS Stimulation of the motor cortex via TMS successfully elicited evoked responses in contralateral hand muscles in 5 patients. The location of primary motor cortex in the precentral gyrus identified by TMS corresponded with the postcentral location of the primary sensory cortex identified by MEG in 2 patients and to the sensorimotor cortex identified by fMRI in 3 children. In this cohort, we demonstrate that TMS can illuminate abnormalities in motor physiology including motor reorganization. We also demonstrate the feasibility of using TMS-derived contralateral silent periods to approximate the location of motor cortex in the absence of an evoked response. When compared to chronological age, performance functioning level appears to be better in predicting successful mapping outcome with TMS. CONCLUSIONS Our findings indicate that awake TMS is a safe alternative to MEG and fMRI performed under sedation to localize the motor cortex and provides additional insight into the underlying pathophysiology and motor plasticity in toddlers.
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Affiliation(s)
- Shalini Narayana
- Division of Clinical Neurosciences, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee; Le Bonheur Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, Tennessee; Department of Neurobiology and Anatomy, University of Tennessee Health Science Center, Memphis, Tennessee.
| | - Roozbeh Rezaie
- Division of Clinical Neurosciences, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee; Le Bonheur Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, Tennessee
| | - Samuel S McAfee
- Le Bonheur Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, Tennessee
| | - Asim F Choudhri
- Le Bonheur Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, Tennessee; Department of Radiology, University of Tennessee Health Science Center, Memphis, Tennessee; Department of Neurosurgery, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Abbas Babajani-Feremi
- Division of Clinical Neurosciences, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee; Le Bonheur Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, Tennessee
| | - Stephen Fulton
- Le Bonheur Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, Tennessee; Division of Pediatric Neurology, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Frederick A Boop
- Le Bonheur Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, Tennessee; Department of Neurosurgery, University of Tennessee Health Science Center, Memphis, Tennessee
| | - James W Wheless
- Le Bonheur Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, Tennessee; Division of Pediatric Neurology, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Andrew C Papanicolaou
- Division of Clinical Neurosciences, Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee; Le Bonheur Neuroscience Institute, Le Bonheur Children's Hospital, Memphis, Tennessee; Department of Neurobiology and Anatomy, University of Tennessee Health Science Center, Memphis, Tennessee
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Mathern GW, Beninsig L, Nehlig A. From the editors: Epilepsia's survey on the necessity of the Wada test and intracranial electrodes for cortical mapping. Epilepsia 2014; 55:1887-9. [PMID: 25358628 DOI: 10.1111/epi.12815] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/27/2014] [Indexed: 11/26/2022]
Abstract
OBJECTIVE From April 4 to August 1, 2014, Epilepsia conducted an online survey seeking opinions related to the use of the Wada test and intracranial electrodes in localizing cortical functions for epilepsy surgery patients. This study reports the findings of that poll. METHODS The survey consisted of six questions. Two questions addressed: (1) If a Wada test was always necessary for patients with temporal lobe epilepsy; and (2) if magnetoencephalography (MEG) and functional magnetic resonance imaging (fMRI) data could replace intracranial electrodes in localizing cortical motor-sensory and language functions. Four questions addressed the type of medical personnel, geographic region of residence based on International League Against Epilepsy (ILAE) regions, if responders had read the paper, and if they were ILAE/International Bureau for Epilepsy (IBE) members. RESULTS Of 115 that started the survey, 92 (80%) completed it, and most were epilepsy specialists (87%) from North America (49%) and Europe (28%). Of responders, 85% indicated that Wada tests were unnecessary for temporal lobe epilepsy surgery patients. There were differences based on residency, with 100% of those from Europe indicating that the Wada test was unnecessary compared with 75% of those from North America (p = 0.01). Of responders, 56% indicated that intracranial electrodes were necessary to localize functional cortex. SIGNIFICANCE This survey found that the majority considered the Wada test unnecessary for temporal lobe epilepsy surgery patients, with more of those from Europe saying it is not needed compared with North America. In addition, just over half indicated that intracranial electrodes are still needed to localize motor-sensory and language functions. These findings, although based on opinions, support that there are divergent views on the use of these procedures in epilepsy surgery patients that require additional study.
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Affiliation(s)
- Gary W Mathern
- Departments of Neurosurgery and Psychiatry & BioBehavioral Medicine, David Geffen School of Medicine, The Mattel Children's Hospital, University of California, Los Angeles, California, U.S.A
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Frye RE, Liederman J. Cortical organization of language pathways in children with non-localized cryptogenic epilepsy. Front Hum Neurosci 2014; 8:808. [PMID: 25346681 PMCID: PMC4191195 DOI: 10.3389/fnhum.2014.00808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 09/22/2014] [Indexed: 11/20/2022] Open
Abstract
Children with a history of epilepsy are almost six times more likely than their unaffected siblings to be referred for speech or language therapy. However, the abnormalities in neural pathway that cause these delays are poorly understood. We recorded evoked fields using whole-head magnetoencephalography during real and non-word visual and auditory rhyme tasks in 15 children with non-localized cryptogenic epilepsy. Basic phonological and orthographic language skills were assessed using Woodcock–Johnson Test of Achievement subtests. Dynamic statistical parameter mapping was used with individual participant magnetic resonance images. Significant cortical activity was visualized on average and performance weighted maps. For the auditory rhyme tasks, bilateral primary and secondary auditory cortices, the superior temporal sulcus, and insular cortex were activated early with later increases in left hemisphere activity. Visual rhyme tasks evoked early bilateral primary and secondary occipital cortical and angular gyri activity followed by later activation of the planum temporale and supramarginal gyri and the left ventral occipitotemporal area. For the auditory rhyme tasks, performance weighted maps demonstrated that early right hemisphere activation was associated with poorer reading skills while later activity was associated with better reading skills; for the left hemisphere, greater early activation of the secondary auditory cortex, including the planum temporale, was related to better reading skills while relatively later activation of these areas was associated with poorer reading skills. For the visual rhyme tasks, greater activity in the bilateral ventral occipitotemporal and insular areas and angular and supramarginal gyri were associated with better performance. These data suggest that spatiotemporal cortical activation patterns are associated with variations in language performance in non-localized cryptogenic epilepsy.
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Affiliation(s)
- Richard Eugene Frye
- Department of Pediatrics, University of Arkansas for Medical Sciences , Little Rock, AR , USA ; Arkansas Children's Hospital Research Institute , Little Rock, AR , USA
| | - Jacqueline Liederman
- Department of Psychological and Brain Sciences, Boston University , Boston, MA , USA
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Rezaie R, Narayana S, Schiller K, Birg L, Wheless JW, Boop FA, Papanicolaou AC. Assessment of hemispheric dominance for receptive language in pediatric patients under sedation using magnetoencephalography. Front Hum Neurosci 2014; 8:657. [PMID: 25191260 PMCID: PMC4140211 DOI: 10.3389/fnhum.2014.00657] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 08/06/2014] [Indexed: 12/11/2022] Open
Abstract
Non-invasive assessment of hemispheric dominance for receptive language using magnetoencephalography (MEG) is now a well-established procedure used across several epilepsy centers in the context of pre-surgical evaluation of children and adults while awake, alert and attentive. However, the utility of MEG for the same purpose, in cases of sedated patients, is contested. Establishment of the efficiency of MEG is especially important in the case of children who, for a number of reasons, must be assessed under sedation. Here we explored the efficacy of MEG language mapping under sedation through retrospective review of 95 consecutive pediatric patients, who underwent our receptive language test as part of routine clinical evaluation. Localization of receptive language cortex and subsequent determination of laterality was successfully completed in 78% (n = 36) and 55% (n = 27) of non-sedated and sedated patients, respectively. Moreover, the proportion of patients deemed left hemisphere dominant for receptive language did not differ between non-sedated and sedated patients, exceeding 90% in both groups. Considering the challenges associated with assessing brain function in pediatric patients, the success of passive MEG in the context of the cases reviewed in this study support the utility of this method in pre-surgical receptive language mapping.
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Affiliation(s)
- Roozbeh Rezaie
- Department of Pediatrics, Division of Clinical Neurosciences, University of Tennessee Health Science Center Memphis, TN, USA ; Neuroscience Institute, Le Bonheur Children's Hospital Memphis, TN, USA
| | - Shalini Narayana
- Department of Pediatrics, Division of Clinical Neurosciences, University of Tennessee Health Science Center Memphis, TN, USA ; Neuroscience Institute, Le Bonheur Children's Hospital Memphis, TN, USA
| | | | - Liliya Birg
- Neuroscience Institute, Le Bonheur Children's Hospital Memphis, TN, USA
| | - James W Wheless
- Neuroscience Institute, Le Bonheur Children's Hospital Memphis, TN, USA ; Division of Pediatric Neurology, Department of Pediatrics, University of Tennessee Health Science Center Memphis, TN, USA
| | - Frederick A Boop
- Neuroscience Institute, Le Bonheur Children's Hospital Memphis, TN, USA ; Department of Neurosurgery, University of Tennessee Health Science Center Memphis, TN, USA
| | - Andrew C Papanicolaou
- Department of Pediatrics, Division of Clinical Neurosciences, University of Tennessee Health Science Center Memphis, TN, USA ; Neuroscience Institute, Le Bonheur Children's Hospital Memphis, TN, USA
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Mathern G, Nehlig A. From the editors : IntroducingEpilepsia'sControversy in Epilepsy series. Epilepsia 2014; 55:627-628. [DOI: 10.1111/epi.12590] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Loring DW, Gaillard WD, Bookheimer SY, Meador KJ, Ojemann JG. Cortical cartography reveals political and physical maps. Epilepsia 2014; 55:633-637. [PMID: 24815217 PMCID: PMC4197796 DOI: 10.1111/epi.12553] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/03/2014] [Indexed: 11/28/2022]
Abstract
Advances in functional imaging have provided noninvasive techniques to probe brain organization of multiple constructs including language and memory. Because of high overall rates of agreements with older techniques, including Wada testing and cortical stimulation mapping (CSM), some have proposed that those approaches should be largely abandoned because of their invasiveness, and replaced with noninvasive functional imaging methods. High overall agreement, however, is based largely on concordant language lateralization in series dominated by cases of typical cerebral dominance. Advocating a universal switch from Wada testing and cortical stimulation mapping to functional magnetic resonance imaging (fMRI) or magnetoencephalography (MEG) ignores the differences in specific expertise across epilepsy centers, many of which often have greater skill with one approach rather than the other, and that Wada, CSM, fMRI, and MEG protocols vary across institutions resulting in different outcomes and reliability. Specific patient characteristics also affect whether Wada or CSM might influence surgical management, making it difficult to accept broad recommendations against currently useful clinical tools. Although the development of noninvasive techniques has diminished the frequency of more invasive approaches, advocating their use to replace Wada testing and CSM across all epilepsy surgery programs without consideration of the different skills, protocols, and expertise at any given center site is ill-advised.
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Affiliation(s)
- David W. Loring
- Departments of Neurology and Pediatrics, Emory University, Atlanta, GA
| | | | | | - Kimford J. Meador
- Department of Neurology & Neurological Sciences, Stanford University, Stanford, CA
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