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Bajracharya A, Peelle JE. A systematic review of neuroimaging approaches to mapping language in individuals. JOURNAL OF NEUROLINGUISTICS 2023; 68:101163. [PMID: 37637379 PMCID: PMC10449384 DOI: 10.1016/j.jneuroling.2023.101163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/29/2023]
Abstract
Although researchers often rely on group-level fMRI results to draw conclusions about the neurobiology of language, doing so without accounting for the complexities of individual brains may reduce the validity of our findings. Furthermore, understanding brain organization in individuals is critically important for both basic science and clinical translation. To assess the state of single-subject language localization in the functional neuroimaging literature, we carried out a systematic review of studies published through April 2020. Out of 977 papers identified through our search, 121 met our inclusion criteria for reporting single-subject fMRI results (fMRI studies of language in adults that report task-based single-subject statistics). Of these, 20 papers reported using a single-subject test-retest analysis to assess reliability. Thus, we found that a relatively modest number of papers reporting single-subject results quantified single-subject reliability. These varied substantially in acquisition parameters, task design, and reliability measures, creating significant challenges for making comparisons across studies. Future endeavors to optimize the localization of language networks in individuals will benefit from the standardization and broader reporting of reliability metrics for different tasks and acquisition parameters.
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Affiliation(s)
| | - Jonathan E Peelle
- Center for Cognitive and Brain Health, Department of Communication Sciences and Disorders, and Department of Psychology, Northeastern University
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2
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Abarrategui B, Mariani V, Rizzi M, Berta L, Scarpa P, Zauli FM, Squarza S, Banfi P, d’Orio P, Cardinale F, Del Vecchio M, Caruana F, Avanzini P, Sartori I. Language lateralization mapping (reversibly) masked by non-dominant focal epilepsy: a case report. Front Hum Neurosci 2023; 17:1254779. [PMID: 37900727 PMCID: PMC10600519 DOI: 10.3389/fnhum.2023.1254779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 09/15/2023] [Indexed: 10/31/2023] Open
Abstract
Language lateralization in patients with focal epilepsy frequently diverges from the left-lateralized pattern that prevails in healthy right-handed people, but the mechanistic explanations are still a matter of debate. Here, we debate the complex interaction between focal epilepsy, language lateralization, and functional neuroimaging techniques by introducing the case of a right-handed patient with unaware focal seizures preceded by aphasia, in whom video-EEG and PET examination suggested the presence of focal cortical dysplasia in the right superior temporal gyrus, despite a normal structural MRI. The functional MRI for language was inconclusive, and the neuropsychological evaluation showed mild deficits in language functions. A bilateral stereo-EEG was proposed confirming the right superior temporal gyrus origin of seizures, revealing how ictal aphasia emerged only once seizures propagated to the left superior temporal gyrus and confirming, by cortical mapping, the left lateralization of the posterior language region. Stereo-EEG-guided radiofrequency thermocoagulations of the (right) focal cortical dysplasia not only reduced seizure frequency but led to the normalization of the neuropsychological assessment and the "restoring" of a classical left-lateralized functional MRI pattern of language. This representative case demonstrates that epileptiform activity in the superior temporal gyrus can interfere with the functioning of the contralateral homologous cortex and its associated network. In the case of presurgical evaluation in patients with epilepsy, this interference effect must be carefully taken into consideration. The multimodal language lateralization assessment reported for this patient further suggests the sensitivity of different explorations to this interference effect. Finally, the neuropsychological and functional MRI changes after thermocoagulations provide unique cues on the network pathophysiology of focal cortical dysplasia and the role of diverse techniques in indexing language lateralization in complex scenarios.
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Affiliation(s)
- Belén Abarrategui
- “Claudio Munari” Epilepsy Surgery Center, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy
- Department of Neurology, Hospital Universitario Puerta de Hierro, Majadahonda, Spain
| | - Valeria Mariani
- “Claudio Munari” Epilepsy Surgery Center, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy
- Neurology and Stroke Unit, ASST Santi Paolo e Carlo, Presidio San Carlo Borromeo, Milan, Italy
| | - Michele Rizzi
- “Claudio Munari” Epilepsy Surgery Center, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy
- Department of Neurosurgery, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Luca Berta
- Department of Medical Physics, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy
| | - Pina Scarpa
- Cognitive Neuropsychology Centre, Department of Neuroscience, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy
| | - Flavia Maria Zauli
- “Claudio Munari” Epilepsy Surgery Center, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy
- Department of Biomedical and Clinical Sciences, Università degli Studi di Milano, Milan, Italy
- Department of Philosophy “P. Martinetti”, Università degli Studi di Milano, Milan, Italy
| | - Silvia Squarza
- Department of Neuroradiology, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy
| | - Paola Banfi
- Neurology and Stroke Unit, ASST Sette Laghi Ospedale di Circolo, Varese, Italy
| | - Piergiorgio d’Orio
- “Claudio Munari” Epilepsy Surgery Center, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy
- Unit of Neuroscience, Department of Medicine and Surgery, Università degli Studi di Parma, Parma, Italy
- Institute of Neuroscience, Consiglio Nazionale delle Ricerche, Parma, Italy
| | - Francesco Cardinale
- “Claudio Munari” Epilepsy Surgery Center, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy
- Unit of Neuroscience, Department of Medicine and Surgery, Università degli Studi di Parma, Parma, Italy
- Institute of Neuroscience, Consiglio Nazionale delle Ricerche, Parma, Italy
| | - Maria Del Vecchio
- Institute of Neuroscience, Consiglio Nazionale delle Ricerche, Parma, Italy
| | - Fausto Caruana
- Institute of Neuroscience, Consiglio Nazionale delle Ricerche, Parma, Italy
| | - Pietro Avanzini
- Institute of Neuroscience, Consiglio Nazionale delle Ricerche, Parma, Italy
| | - Ivana Sartori
- “Claudio Munari” Epilepsy Surgery Center, ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy
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Zahnert F, Kräling G, Melms L, Belke M, Kleinholdermann U, Timmermann L, Hirsch M, Jansen A, Mross P, Menzler K, Habermehl L, Knake S. Diffusion magnetic resonance imaging connectome features are predictive of functional lateralization of semantic processing in the anterior temporal lobes. Hum Brain Mapp 2022; 44:496-508. [PMID: 36098483 PMCID: PMC9842893 DOI: 10.1002/hbm.26074] [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: 03/16/2022] [Revised: 07/22/2022] [Accepted: 08/18/2022] [Indexed: 01/25/2023] Open
Abstract
Assessment of regional language lateralization is crucial in many scenarios, but not all populations are suited for its evaluation via task-functional magnetic resonance imaging (fMRI). In this study, the utility of structural connectome features for the classification of language lateralization in the anterior temporal lobes (ATLs) was investigated. Laterality indices for semantic processing in the ATL were computed from task-fMRI in 1038 subjects from the Human Connectome Project who were labeled as stronger rightward lateralized (RL) or stronger leftward to bilaterally lateralized (LL) in a data-driven approach. Data of unrelated subjects (n = 432) were used for further analyses. Structural connectomes were generated from diffusion-MRI tractography, and graph theoretical metrics (node degree, betweenness centrality) were computed. A neural network (NN) and a random forest (RF) classifier were trained on these metrics to classify subjects as RL or LL. After classification, comparisons of network measures were conducted via permutation testing. Degree-based classifiers produced significant above-chance predictions both during cross-validation (NN: AUC-ROC[CI] = 0.68[0.64-0.73], accuracy[CI] = 68.34%[63-73.2%]; RF: AUC-ROC[CI] = 0.7[0.66-0.73], accuracy[CI] = 64.81%[60.9-68.5]) and testing (NN: AUC-ROC[CI] = 0.69[0.53-0.84], accuracy[CI] = 68.09[53.2-80.9]; RF: AUC-ROC[CI] = 0.68[0.53-0.84], accuracy[CI] = 68.09[55.3-80.9]). Comparison of network metrics revealed small effects of increased node degree within the right posterior middle temporal gyrus (pMTG) in subjects with RL, while degree was decreased in the right posterior cingulate cortex (PCC). Above-chance predictions of functional language lateralization in the ATL are possible based on diffusion-MRI connectomes alone. Increased degree within the right pMTG as a right-sided homologue of a known semantic hub, and decreased hubness of the right PCC may form a structural basis for rightward-lateralized semantic processing.
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Affiliation(s)
- Felix Zahnert
- Epilepsy Center Hesse, Department for NeurologyUniversity Hospital Marburg, Philipps University MarburgMarburgGermany
| | - Gunter Kräling
- Department of Medical TechnologyUniversity Hospital MarburgMarburgGermany
| | - Leander Melms
- Institute for Artificial IntelligenceUniversity Hospital Marburg, Philipps University MarburgMarburgGermany
| | - Marcus Belke
- Epilepsy Center Hesse, Department for NeurologyUniversity Hospital Marburg, Philipps University MarburgMarburgGermany,LOEWE Center for Personalized Translational Epilepsy Research (CePTER)Goethe‐University FrankfurtFrankfurt Am MainGermany
| | - Urs Kleinholdermann
- Department for NeurologyUniversity Hospital Marburg, Philipps University MarburgMarburgGermany
| | - Lars Timmermann
- Department for NeurologyUniversity Hospital Marburg, Philipps University MarburgMarburgGermany,Center for Mind, Brain and Behavior (CMBB)Philipps‐University MarburgMarburgGermany,Core Facility Brainimaging, Faculty of MedicineUniversity of MarburgMarburgGermany
| | - Martin Hirsch
- Institute for Artificial IntelligenceUniversity Hospital Marburg, Philipps University MarburgMarburgGermany
| | - Andreas Jansen
- Center for Mind, Brain and Behavior (CMBB)Philipps‐University MarburgMarburgGermany,Core Facility Brainimaging, Faculty of MedicineUniversity of MarburgMarburgGermany,Department for Psychiatry and PsychotherapyUniversity Hospital Marburg, Philipps University MarburgMarburgGermany
| | - Peter Mross
- Epilepsy Center Hesse, Department for NeurologyUniversity Hospital Marburg, Philipps University MarburgMarburgGermany
| | - Katja Menzler
- Epilepsy Center Hesse, Department for NeurologyUniversity Hospital Marburg, Philipps University MarburgMarburgGermany,Center for Mind, Brain and Behavior (CMBB)Philipps‐University MarburgMarburgGermany,Core Facility Brainimaging, Faculty of MedicineUniversity of MarburgMarburgGermany
| | - Lena Habermehl
- Epilepsy Center Hesse, Department for NeurologyUniversity Hospital Marburg, Philipps University MarburgMarburgGermany
| | - Susanne Knake
- Epilepsy Center Hesse, Department for NeurologyUniversity Hospital Marburg, Philipps University MarburgMarburgGermany,LOEWE Center for Personalized Translational Epilepsy Research (CePTER)Goethe‐University FrankfurtFrankfurt Am MainGermany,Center for Mind, Brain and Behavior (CMBB)Philipps‐University MarburgMarburgGermany,Core Facility Brainimaging, Faculty of MedicineUniversity of MarburgMarburgGermany
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4
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Chen Y, Xing X, Dai W, Tian L, Dong Z, Yu S. Brain regions involved in fractional amplitude of low-frequency fluctuation in cluster headache patients: a resting-state functional MRI study. BMC Neurol 2022; 22:336. [PMID: 36071405 PMCID: PMC9450424 DOI: 10.1186/s12883-022-02863-3] [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: 05/04/2022] [Accepted: 08/29/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND We used resting-state functional magnetic resonance imaging (RS-fMRI) to assess the possible pathogenic role of fALFF in CH. A limited number of studies have reported on fractional amplitude of low-frequency fluctuation (fALFF) in cluster headache (CH). METHODS RS-fMRI scans of 23 patients with CH were obtained (11with left-sided headache and 12 with right-sided headache), along with scans of 23 age- and sex-matched normal controls. The RS-fMRI data were analyzed to explore abnormal brain activity in the left CH and right CH patients during the non-painful state in one cluster period. fALFF was compared between patients and controls, and correlation analysis between the regional mean fALFF values and clinical characteristics was performed. RESULTS A decrease in fALFF was detected in the left cerebellum, left lentiform nucleus, left frontal lobe, left anterior cingulate, and right postcentral gyrus in the left CH group compared to the controls, while a decrease of fALFF was detected in the right cerebellum, right cingulate gyrus, right superior parietal lobule, right inferior parietal lobule, right postcentral gyrus, and left precuneus in the right CH group. No patient had a region with increased fALFF. A moderate correlation was observed between some regional mean fALFF values and the clinical characteristics. CONCLUSIONS We deduced that dysfunction in multiple brain areas is involved in the non-painful state of CH during a cluster period.
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Affiliation(s)
- Yun Chen
- Department of Neurology, Chinese PLA General Hospital; International headache center, Chinese PLA General Hospital, Beijing, China.,Chinese PLA Medical School, Beijing, 100853, China.,Department of Neurology, Peking University Shougang Hospital, Beijing, 100144, China
| | - Xinbo Xing
- Department of Radiology, Fourth Medical Center of Chinese PLA General Hospital, Beijing, 100048, China
| | - Wei Dai
- Department of Neurology, Chinese PLA General Hospital; International headache center, Chinese PLA General Hospital, Beijing, China.,Chinese PLA Medical School, Beijing, 100853, China
| | - Lixia Tian
- School of Computer and Information Technology, Beijing Jiaotong University, Beijing, 100044, China
| | - Zhao Dong
- Department of Neurology, Chinese PLA General Hospital; International headache center, Chinese PLA General Hospital, Beijing, China.
| | - Shengyuan Yu
- Department of Neurology, Chinese PLA General Hospital; International headache center, Chinese PLA General Hospital, Beijing, China.
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5
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Matsuo K, Kono K, Yasui-Furukori N, Shimoda K, Kaji Y, Akiyama K. HomotopicLI: Rationale, characteristics, and implications of a new threshold-free lateralization index of functional magnetic resonance imaging. Laterality 2022; 27:513-543. [PMID: 35948519 DOI: 10.1080/1357650x.2022.2109655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The reliable preoperative estimation of brain hemispheric asymmetry may be achieved through multiple lateralization indices using functional magnetic resonance imaging. Adding to our previously developed AveLI, we devised a novel threshold-free lateralization index, HomotopicLI, which computes a basic formula, (Left - Right) / (Left + Right), using voxel values of pairs located symmetrically in relation to the midsagittal line as the terms Left and Right, and averages them within the regions-of-interest. The study aimed to evaluate HomotopicLI before clinical applications. Data were collected from 56 healthy participants who performed four language tasks. We compared seven index types, including HomotopicLI, AveLI, and BaseLI; BaseLI was calculated using the sums of voxel values as the terms. Contrary to our expectations, HomotopicLI performed similarly to AveLI but better than BaseLI in detecting right dominance. A detailed analysis of unilaterally activated voxels of the homotopic pairs revealed that unilateral activation occurred more frequently on the right than on the left when HomotopicLI indicated right dominance. The voxel values during right unilateral activation were smaller than those in the left, causing right dominances in the homotopic pairs by HomotopicLI. These unique features provide an advantage in detecting residual, compensative functions spreading weakly in the non-dominant hemisphere.
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Affiliation(s)
- Kayako Matsuo
- Center for Research Collaboration and Support, Dokkyo Medical University School of Medicine, Tochigi, Japan.,Graduate School of Informatics and Engineering, The University of Electro-Communications, Chofu, Japan
| | - Kenta Kono
- Dokkyo Medical University School of Medicine, Tochigi, Japan
| | - Norio Yasui-Furukori
- Department of Psychiatry, Dokkyo Medical University School of Medicine, Tochigi, Japan
| | - Kazutaka Shimoda
- Department of Psychiatry, Dokkyo Medical University School of Medicine, Tochigi, Japan
| | - Yasushi Kaji
- Department of Radiology, Dokkyo Medical University School of Medicine, Tochigi, Japan
| | - Kazufumi Akiyama
- Department of Biological Psychiatry and Neuroscience, Dokkyo Medical University School of Medicine, Tochigi, Japan.,Kawada Hospital, Okayama, Japan
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6
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Elin K, Malyutina S, Bronov O, Stupina E, Marinets A, Zhuravleva A, Dragoy O. A New Functional Magnetic Resonance Imaging Localizer for Preoperative Language Mapping Using a Sentence Completion Task: Validity, Choice of Baseline Condition, and Test–Retest Reliability. Front Hum Neurosci 2022; 16:791577. [PMID: 35431846 PMCID: PMC9006995 DOI: 10.3389/fnhum.2022.791577] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 03/04/2022] [Indexed: 11/24/2022] Open
Abstract
To avoid post-neurosurgical language deficits, intraoperative mapping of the language function in the brain can be complemented with preoperative mapping with functional magnetic resonance imaging (fMRI). The validity of an fMRI “language localizer” paradigm crucially depends on the choice of an optimal language task and baseline condition. This study presents a new fMRI “language localizer” in Russian using overt sentence completion, a task that comprehensively engages the language function by involving both production and comprehension at the word and sentence level. The paradigm was validated in 18 neurologically healthy volunteers who participated in two scanning sessions, for estimating test–retest reliability. For the first time, two baseline conditions for the sentence completion task were compared. At the group level, the paradigm significantly activated both anterior and posterior language-related regions. Individual-level analysis showed that activation was elicited most consistently in the inferior frontal regions, followed by posterior temporal regions and the angular gyrus. Test–retest reliability of activation location, as measured by Dice coefficients, was moderate and thus comparable to previous studies. Test–retest reliability was higher in the frontal than temporo-parietal region and with the most liberal statistical thresholding compared to two more conservative thresholding methods. Lateralization indices were expectedly left-hemispheric, with greater lateralization in the frontal than temporo-parietal region, and showed moderate test-retest reliability. Finally, the pseudoword baseline elicited more extensive and more reliable activation, although the syllable baseline appears more feasible for future clinical use. Overall, the study demonstrated the validity and reliability of the sentence completion task for mapping the language function in the brain. The paradigm needs further validation in a clinical sample of neurosurgical patients. Additionally, the study contributes to general evidence on test–retest reliability of fMRI.
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Affiliation(s)
- Kirill Elin
- Center for Language and Brain, HSE University, Moscow, Russia
| | - Svetlana Malyutina
- Center for Language and Brain, HSE University, Moscow, Russia
- *Correspondence: Svetlana Malyutina,
| | - Oleg Bronov
- Department of Radiology, National Medical and Surgical Center Named After N.I. Pirogov, Moscow, Russia
| | | | - Aleksei Marinets
- Department of Radiology, National Medical and Surgical Center Named After N.I. Pirogov, Moscow, Russia
| | - Anna Zhuravleva
- Center for Language and Brain, HSE University, Moscow, Russia
| | - Olga Dragoy
- Center for Language and Brain, HSE University, Moscow, Russia
- Institute of Linguistics, Russian Academy of Sciences, Moscow, Russia
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7
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Benjamin CFA. Cognitive Biomarkers in the Clinic: Lessons From Presurgical fMRI. J Clin Neurophysiol 2022; 39:121-128. [PMID: 34366397 DOI: 10.1097/wnp.0000000000000834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SUMMARY Cognitive biomarkers are vital and uniquely challenging clinical tools. There has been marked growth in neuroimaging-based cognitive biomarkers across the past 40 years with more in development (e.g., clinical cognitive EEG). The challenges involved in developing cognitive biomarkers and key milestones in their development are reviewed here using clinical functional MRI's evolution as a case study. It is argued that indexing cognition is uniquely challenging because it requires patients to consistently use specific cognitive processes, and it is difficult or impossible to independently verify this occurred. This limitation can be successfully managed through careful analysis of standardized protocols for acquisition and interpretation, and ensuring the clinical application of biomarkers integrates disciplines with complementary expertise. Factors beneficial to the adoption of a novel cognitive biomarker include a clinical need and inadequate alternatives. Key milestones in the development of functional MRI included (1) demonstration that its performance was equivalent to its predecessor; (2) demonstration it predicted a clinically meaningful outcome; and (3) the establishment of infrastructure for both its execution and billing. Review of functional MRI and its predecessors suggest a cycle whereby successful cognitive biomarkers are validated, experience widespread adoption and customization/fragmentation, go through a period of review, and finally are refined and standardized. Those applying future cognitive biomarkers in the clinic can avoid some of the failures of clinical functional MRI by defining the skills and disciplines the method requires and routinely evaluating patient outcomes.
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8
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Koop JI, Credille K, Wang Y, Loman M, Marashly A, Kim I, Lew SM, Maheshwari M. Determination of language dominance in pediatric patients with epilepsy for clinical decision-making: Correspondence of intracarotid amobarbitol procedure and fMRI modalities. Epilepsy Behav 2021; 121:108041. [PMID: 34082317 DOI: 10.1016/j.yebeh.2021.108041] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 05/04/2021] [Accepted: 05/04/2021] [Indexed: 11/29/2022]
Abstract
Identification of the language dominant hemisphere is an essential part of the evaluation of potential pediatric epilepsy surgery patients. Historically, language dominance has been determined using the intracarotid amobarbitol procedure (IAP), but use of functional Magnetic Resonance Imaging (fMRI) scanning is becoming more common. Few studies examine the correspondence between fMRI and IAP in pediatric samples. The current study examined the agreement of hemispheric lateralization as determined by fMRI and IAP in a consecutive sample of 10 pediatric patients with epilepsy evaluated for epilepsy surgery. Data showed a strong correlation between IAP and fMRI lateralilty indices (r=.91) and 70% agreement in determination of hemispheric dominance, despite increased demonstration of bilateral or atypical language representation in this pediatric sample. Clinical implications and interpretation challenges are discussed.
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Affiliation(s)
- Jennifer I Koop
- Department of Neurology (Neuropsychology), Medical College of Wisconsin, Milwaukee, WI, United States.
| | - Kevin Credille
- Medical College of Wisconsin, Milwaukee, WI, United States
| | - Yang Wang
- Department of Radiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Michelle Loman
- Department of Neurology (Neuropsychology), Medical College of Wisconsin, Milwaukee, WI, United States
| | - Ahmad Marashly
- Division of Pediatric Neurology, University of Washington/Seattle Children's Hospital, Seattle, WA, United States
| | - Irene Kim
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Sean M Lew
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Mohit Maheshwari
- Department of Radiology, Medical College of Wisconsin, Milwaukee, WI, United States
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9
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Whitten A, Jacobs ML, Englot DJ, Rogers BP, Levine KK, González HFJ, Morgan VL. Resting-state hippocampal networks related to language processing reveal unique patterns in temporal lobe epilepsy. Epilepsy Behav 2021; 117:107834. [PMID: 33610102 PMCID: PMC8035309 DOI: 10.1016/j.yebeh.2021.107834] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/22/2021] [Accepted: 01/26/2021] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Patients with temporal lobe epilepsy (TLE) commonly experience a broad range of language impairments. These deficits are thought to arise from repeated seizure activity that damages language regions. However, connectivity between the seizure onset region in the hippocampus and regions related to language processing has rarely been studied, and could also have a strong impact on language function. The purpose of this study was to use resting-state functional connectivity (FC) measures to assess hippocampal network patterns and their relation to language abilities in patients with right TLE (RLTE), left TLE (LTLE), and healthy controls. METHODS Presurgical resting-state 3T functional MRI data were acquired from 40 patients with mesial TLE (27 RTLE, 13 LTLE) and 54 controls. The regions of interest were the anterior and posterior bilateral hippocampi and eleven regions grouped by frontal or temporo-parietal locations, including large areas of language-related cortex. FC values were computed with the right/left anterior and posterior hippocampi as the seeds and frontal and temporo-parietal regions as targets. Resting-state lateralization indices were also calculated (LI-Rest), and all FC measures were correlated to neuropsychological language scores and measures related to manifestation of epilepsy including age of onset, duration of disease, monthly seizure frequency, and hippocampal volume. RESULTS We found significant group differences between the anterior hippocampi and temporo-parietal regions closest to the seizure focus, in which RTLE and LTLE showed stronger connectivity to their contralateral hippocampus, while controls showed similar connectivity to both hippocampi. In addition, LI-Rest demonstrated significantly more right lateralization in LTLE compared to RTLE for temporo-parietal regions only. In LTLE, we found significant associations between stronger hippocampal network resting-state FC and later age of onset and decreased left anterior hippocampal volume. SIGNIFICANCE The results of our study indicate that the presence of TLE impacts hippocampal-temporo-parietal networks relevant to language processing.
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Affiliation(s)
- Allison Whitten
- Institute of Imaging Science, Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, USA
| | - Monica L Jacobs
- Department of Neurological Surgery, Vanderbilt University Medical Center, USA
| | - Dario J Englot
- Institute of Imaging Science, Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, USA; Department of Neurological Surgery, Vanderbilt University Medical Center, USA; Department of Biomedical Engineering, Vanderbilt University, USA
| | - Baxter P Rogers
- Institute of Imaging Science, Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, USA; Department of Biomedical Engineering, Vanderbilt University, USA
| | - Kaela K Levine
- Institute of Imaging Science, Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, USA
| | - Hernán F J González
- Institute of Imaging Science, Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, USA; Department of Biomedical Engineering, Vanderbilt University, USA
| | - Victoria L Morgan
- Institute of Imaging Science, Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, USA; Department of Neurological Surgery, Vanderbilt University Medical Center, USA; Department of Biomedical Engineering, Vanderbilt University, USA.
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10
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Olaru M, Nillo RM, Mukherjee P, Sugrue LP. A quantitative approach for measuring laterality in clinical fMRI for preoperative language mapping. Neuroradiology 2021; 63:1489-1500. [PMID: 33772347 PMCID: PMC8376727 DOI: 10.1007/s00234-021-02685-z] [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: 09/15/2020] [Accepted: 03/01/2021] [Indexed: 11/16/2022]
Abstract
Purpose fMRI is increasingly used for presurgical language mapping, but lack of standard methodology has made it difficult to combine/compare data across institutions or determine the relative efficacy of different approaches. Here, we describe a quantitative analytic framework for determining language laterality in clinical fMRI that addresses these concerns. Methods We retrospectively analyzed fMRI data from 59 patients who underwent presurgical language mapping at our institution with identical imaging and behavioral protocols. First, we compared the efficacy of different regional masks in capturing language activations. Then, we systematically explored how laterality indices (LIs) computed from these masks vary as a function of task and activation threshold. Finally, we determined the percentile threshold that maximized the correlation between the results of our LI approach and the laterality assessments from the original clinical radiology reports. Results First, we found that a regional mask derived from a meta-analysis of the fMRI literature better captured language task activations than masks based on anatomically defined language areas. Then, we showed that an LI approach based on this functional mask and percentile thresholding of subject activation can quantify the relative ability of different language tasks to lateralize language function at the population level. Finally, we determined that the 92nd percentile of subject-level activation provides the optimal LI threshold with which to reproduce the original clinical reports. Conclusion A quantitative framework for determining language laterality that uses a functionally-derived language mask and percentile thresholding of subject activation can combine/compare results across tasks and patients and reproduce clinical assessments of language laterality. Supplementary Information The online version contains supplementary material available at 10.1007/s00234-021-02685-z.
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Affiliation(s)
- Maria Olaru
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA
| | - Ryan M Nillo
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA
| | - Pratik Mukherjee
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA
| | - Leo P Sugrue
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA.
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11
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Bruckert L, Thompson PA, Watkins KE, Bishop DVM, Woodhead ZVJ. Investigating the effects of handedness on the consistency of lateralization for speech production and semantic processing tasks using functional transcranial Doppler sonography. Laterality 2021; 26:680-705. [PMID: 33715589 DOI: 10.1080/1357650x.2021.1898416] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The left hemisphere is dominant for language in most people, but lateralization strength varies between different tasks and individuals. A large body of literature has shown that handedness is associated with lateralization: left handers have weaker language lateralization on average, and a greater incidence of atypical (right hemisphere) lateralization; but typically, these studies have relied on a single measure of language lateralization. Here we consider the relationships between lateralization for two different language tasks. We investigated the influence of handedness on lateralization using functional transcranial Doppler sonography (fTCD), using an existing dataset (N = 151 adults, 21 left handed). We compared a speech production task (word generation) and a semantic association task. We demonstrated stronger left-lateralization for word generation than semantic association; and a moderate correlation between laterality indices for the two tasks (r = 0.59). Laterality indices were stronger for right than left handers, and left handers were more likely than right handers to have atypical (right hemisphere) lateralization or inconsistent lateralization between the two tasks. These results add to our knowledge of individual differences in lateralization and support the view that language lateralization is multifactorial rather than unitary.
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Affiliation(s)
- L Bruckert
- Department of Experimental Psychology, University of Oxford, Oxford, UK.,Division of Developmental-BehavioralPediatrics, Stanford University School of Medicine, Stanford, CA, USA
| | - P A Thompson
- Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - K E Watkins
- Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - D V M Bishop
- Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - Z V J Woodhead
- Department of Experimental Psychology, University of Oxford, Oxford, UK
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12
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Jansma JM, Rutten GJ, Ramsey LE, Snijders TJ, Bizzi A, Rosengarth K, Dodoo-Schittko F, Hattingen E, de la Peña MJ, von Campe G, Jehna M, Ramsey NF. Automatic identification of atypical clinical fMRI results. Neuroradiology 2020; 62:1677-1688. [PMID: 32812070 PMCID: PMC7666675 DOI: 10.1007/s00234-020-02510-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 07/30/2020] [Indexed: 01/03/2023]
Abstract
Purpose Functional MRI is not routinely used for neurosurgical planning despite potential important advantages, due to difficulty of determining quality. We introduce a novel method for objective evaluation of fMRI scan quality, based on activation maps. A template matching analysis (TMA) is presented and tested on data from two clinical fMRI protocols, performed by healthy controls in seven clinical centers. Preliminary clinical utility is tested with data from low-grade glioma patients. Methods Data were collected from 42 healthy subjects from seven centers, with standardized finger tapping (FT) and verb generation (VG) tasks. Copies of these “typical” data were deliberately analyzed incorrectly to assess feasibility of identifying them as “atypical.” Analyses of the VG task administered to 32 tumor patients assessed sensitivity of the TMA method to anatomical abnormalities. Results TMA identified all atypical activity maps for both tasks, at the cost of incorrectly classifying 3.6 (VG)–6.5% (FT) of typical maps as atypical. For patients, the average TMA was significantly higher than atypical healthy scans, despite localized anatomical abnormalities caused by a tumor. Conclusion This study supports feasibility of TMA for objective identification of atypical activation patterns for motor and verb generation fMRI protocols. TMA can facilitate the use and evaluation of clinical fMRI in hospital settings that have limited access to fMRI experts. In a clinical setting, this method could be applied to automatically flag fMRI scans showing atypical activation patterns for further investigation to determine whether atypicality is caused by poor scan data quality or abnormal functional topography.
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Affiliation(s)
- J Martijn Jansma
- Brain Center, Department of Neurology & Neurosurgery, University Medical Center Utrecht, Utrecht, The Netherlands.,Department of Neurosurgery, Elisabeth-TweeSteden Hospital, Tilburg, The Netherlands
| | - Geert-Jan Rutten
- Department of Neurosurgery, Elisabeth-TweeSteden Hospital, Tilburg, The Netherlands
| | - Lenny E Ramsey
- Department of Neurosurgery, McGovern Medical School, University of Texas Health Science Center, Houston, TX, USA
| | - T J Snijders
- Brain Center, Department of Neurology & Neurosurgery, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Alberto Bizzi
- Neuroradiology Unit, Istituto Clinico Humanitas IRCCS, Rozzano, Milan, Italy
| | - Katharina Rosengarth
- Institute for Experimental Psychology, University of Regensburg, Regensburg, Germany
| | - Frank Dodoo-Schittko
- Medical Sociology, Institute for Epidemiology and Preventive Medicine, University of Regensburg, Regensburg, Germany
| | - Elke Hattingen
- Institute of Neuroradiology, Goethe University, Frankfurt, Germany
| | | | - Gord von Campe
- Department of Neurosurgery, Medical University of Graz, Graz, Austria
| | - Margit Jehna
- Division of Neuroradiology, Vascular and Interventional Radiology, Medical University of Graz, Graz, Austria
| | - Nick F Ramsey
- Brain Center, Department of Neurology & Neurosurgery, University Medical Center Utrecht, Utrecht, The Netherlands. .,Braincarta BV, Utrecht, The Netherlands.
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13
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Brumer I, De Vita E, Ashmore J, Jarosz J, Borri M. Implementation of clinically relevant and robust fMRI-based language lateralization: Choosing the laterality index calculation method. PLoS One 2020; 15:e0230129. [PMID: 32163517 PMCID: PMC7067428 DOI: 10.1371/journal.pone.0230129] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 02/23/2020] [Indexed: 11/19/2022] Open
Abstract
The assessment of language lateralization has become widely used when planning neurosurgery close to language areas, due to individual specificities and potential influence of brain pathology. Functional magnetic resonance imaging (fMRI) allows non-invasive and quantitative assessment of language lateralization for presurgical planning using a laterality index (LI). However, the conventional method is limited by the dependence of the LI on the chosen activation threshold. To overcome this limitation, different threshold-independent LI calculations have been reported. The purpose of this study was to propose a simplified approach to threshold-independent LI calculation and compare it with three previously reported methods on the same cohort of subjects. Fifteen healthy subjects, who performed picture naming, verb generation, and word fluency tasks, were scanned. LI values were calculated for all subjects using four methods, and considering either the whole hemisphere or an atlas-defined language area. For each method, the subjects were ranked according to the calculated LI values, and the obtained rankings were compared. All LI calculation methods agreed in differentiating strong from weak lateralization on both hemispheric and regional scales (Spearman's correlation coefficients 0.59-1.00). In general, a more lateralized activation was found in the language area than in the whole hemisphere. The new method is well suited for application in the clinical practice as it is simple to implement, fast, and robust. The good agreement between LI calculation methods suggests that the choice of method is not key. Nevertheless, it should be consistent to allow a relative comparison of language lateralization between subjects.
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Affiliation(s)
- Irène Brumer
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
- Department of Neuroradiology, King’s College Hospital, London, United Kingdom
| | - Enrico De Vita
- Department of Biomedical Engineering, School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
| | - Jonathan Ashmore
- Department of Neuroradiology, King’s College Hospital, London, United Kingdom
- Department of Medical Physics and Bioengineering, NHS Highland, Inverness, United Kingdom
| | - Jozef Jarosz
- Department of Neuroradiology, King’s College Hospital, London, United Kingdom
| | - Marco Borri
- Department of Neuroradiology, King’s College Hospital, London, United Kingdom
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14
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Woodhead ZV, Rutherford HA, Bishop DV. Measurement of language laterality using functional transcranial Doppler ultrasound: a comparison of different tasks. Wellcome Open Res 2020; 3:104. [PMID: 30345386 PMCID: PMC6171558 DOI: 10.12688/wellcomeopenres.14720.3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/05/2020] [Indexed: 12/31/2022] Open
Abstract
Background: Relative blood flow in the two middle cerebral arteries can be measured using functional transcranial Doppler sonography (fTCD) to give an index of lateralisation as participants perform a specific task. Language laterality has mostly been studied with fTCD using a word generation task, but it is not clear whether this is optimal. Methods: Using fTCD, we evaluated a sentence generation task that has shown good reliability and strong left lateralisation in fMRI. We interleaved trials of word generation, sentence generation and list generation and assessed agreement of these tasks in 31 participants (29 right-handers). Results: Although word generation and sentence generation both gave robust left-lateralisation, lateralisation was significantly stronger for sentence generation. Bland-Altman analysis showed that these two methods were not equivalent. The comparison list generation task was not systematically lateralised, but nevertheless laterality indices (LIs) from this task were significantly correlated with the other two tasks. Subtracting list generation LI from sentence generation LI did not affect the strength of the laterality index. Conclusions: This was a pre-registered methodological study designed to explore novel approaches to optimising measurement of language lateralisation using fTCD. It confirmed that sentence generation gives robust left lateralisation in most people, but is not equivalent to the classic word generation task. Although list generation does not show left-lateralisation at the group level, the LI on this task was correlated with left-lateralised tasks. This suggests that word and sentence generation involve adding a constant directional bias to an underlying continuum of laterality that is reliable in individuals but not biased in either direction. In future research we suggest that consistency of laterality across tasks might have more functional significance than strength or direction of laterality on any one task.
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Affiliation(s)
- Zoe V.J. Woodhead
- Department of Experimental Psychology, University of Oxford, Oxford, UK
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15
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Woodhead ZVJ, Rutherford HA, Bishop DVM. Measurement of language laterality using functional transcranial Doppler ultrasound: a comparison of different tasks. Wellcome Open Res 2020. [PMID: 30345386 DOI: 10.12688/wellcomeopenres.14720.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: Relative blood flow in the two middle cerebral arteries can be measured using functional transcranial Doppler sonography (fTCD) to give an index of lateralisation as participants perform a specific task. Language laterality has mostly been studied with fTCD using a word generation task, but it is not clear whether this is optimal. Methods: Using fTCD, we evaluated a sentence generation task that has shown good reliability and strong left lateralisation in fMRI. We interleaved trials of word generation, sentence generation and list generation and assessed agreement of these tasks in 31 participants (29 right-handers). Results: Although word generation and sentence generation both gave robust left-lateralisation, lateralisation was significantly stronger for sentence generation. Bland-Altman analysis showed that these two methods were not equivalent. The comparison list generation task was not systematically lateralised, but nevertheless laterality indices (LIs) from this task were significantly correlated with the other two tasks. Subtracting list generation LI from sentence generation LI did not affect the strength of the laterality index. Conclusions: This was a pre-registered methodological study designed to explore novel approaches to optimising measurement of language lateralisation using fTCD. It confirmed that sentence generation gives robust left lateralisation in most people, but is not equivalent to the classic word generation task. Although list generation does not show left-lateralisation at the group level, the LI on this task was correlated with left-lateralised tasks. This suggests that word and sentence generation involve adding a constant directional bias to an underlying continuum of laterality that is reliable in individuals but not biased in either direction. In future research we suggest that consistency of laterality across tasks might have more functional significance than strength or direction of laterality on any one task.
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Affiliation(s)
- Zoe V J Woodhead
- Department of Experimental Psychology, University of Oxford, Oxford, UK
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16
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Johnstone LT, Karlsson EM, Carey DP. The validity and reliability of quantifying hemispheric specialisation using fMRI: Evidence from left and right handers on three different cerebral asymmetries. Neuropsychologia 2020; 138:107331. [DOI: 10.1016/j.neuropsychologia.2020.107331] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 12/16/2019] [Accepted: 01/05/2020] [Indexed: 12/21/2022]
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17
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Vingerhoets G. Toward a multidimensional description of individual variation in hemispheric functional segregation: Reply to comments on "Phenotypes in hemispheric functional segregation? Perspectives and challenges". Phys Life Rev 2019; 30:41-46. [PMID: 31818393 DOI: 10.1016/j.plrev.2019.10.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 10/22/2019] [Indexed: 01/25/2023]
Affiliation(s)
- Guy Vingerhoets
- Department of Experimental Psychology, Ghent University, Henri Dunantlaan 2, 9000 Ghent, Belgium.
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18
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Bradshaw AR, Woodhead ZVJ, Thompson PA, Bishop DVM. Investigation into inconsistent lateralisation of language functions as a potential risk factor for language impairment. Eur J Neurosci 2019; 51:1106-1121. [PMID: 31738452 PMCID: PMC7078955 DOI: 10.1111/ejn.14623] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 10/18/2019] [Accepted: 11/12/2019] [Indexed: 01/07/2023]
Abstract
Disruption to language lateralisation has been proposed as a cause of developmental language impairments. In this study, we tested the idea that consistency of lateralisation across different language functions is associated with language ability. A large sample of adults with variable language abilities (N = 67 with a developmental disorder affecting language and N = 37 controls) were recruited. Lateralisation was measured using functional transcranial Doppler sonography (fTCD) for three language tasks that engage different language subprocesses (phonological decision, semantic decision and sentence generation). The whole sample was divided into those with consistent versus inconsistent lateralisation across the three tasks. Language ability (using a battery of standardised tests) was compared between the consistent and inconsistent groups. The results did not show a significant effect of lateralisation consistency on language skills. However, of the 31 individuals showing inconsistent lateralisation, the vast majority (84%) were in the disorder group with only five controls showing such a pattern, a difference that was higher than would be expected by chance. The developmental disorder group also demonstrated weaker correlations between laterality indices across pairs of tasks. In summary, although the data did not support the hypothesis that inconsistent language lateralisation is a major cause of poor language skills, the results suggested that some subtypes of language disorder are associated with inefficient distribution of language functions between hemispheres. Inconsistent lateralisation could be a causal factor in the aetiology of language disorder or may arise in some cases as the consequence of developmental disorder, possibly reflective of compensatory reorganisation.
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Affiliation(s)
- Abigail R Bradshaw
- Department of Experimental Psychology, Radcliffe Observatory Quarter, University of Oxford, Oxford, UK
| | - Zoe V J Woodhead
- Department of Experimental Psychology, Radcliffe Observatory Quarter, University of Oxford, Oxford, UK
| | - Paul A Thompson
- Department of Experimental Psychology, Radcliffe Observatory Quarter, University of Oxford, Oxford, UK
| | - Dorothy V M Bishop
- Department of Experimental Psychology, Radcliffe Observatory Quarter, University of Oxford, Oxford, UK
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19
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Toraman S, Tuncer SA, Balgetir F. Is it possible to detect cerebral dominance via EEG signals by using deep learning? Med Hypotheses 2019; 131:109315. [PMID: 31443748 DOI: 10.1016/j.mehy.2019.109315] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 07/13/2019] [Accepted: 07/19/2019] [Indexed: 11/29/2022]
Abstract
Each brain hemisphere is dominant for certain functions such as speech. The determination of speech laterality prior to surgery is of paramount importance for accurate risk prediction. In this study, we aimed to determine speech laterality via EEG signals by using noninvasive machine learning techniques. The retrospective study included 67 subjects aged 18-65 years who had no chronic diseases and were diagnosed as healthy based on EEG examination. The subjects comprised 35 right-hand dominant (speech center located in the left hemisphere) and 32 left-hand dominant individuals (speech center located in the right hemisphere). A spectrogram was created for each of the 18 EEG channels by using various Convolutional Neural Networks (CNN) architectures including VGG16, VGG19, ResNet, MobileNet, NasNet, and DenseNet. These architectures were used to extract features from the spectrograms. The extracted features were classified using Support Vector Machines (SVM) and the classification performances of the CNN models were evaluated using Area Under the Curve (AUC). Of all the CNN models used in the study, VGG16 had a higher AUC value (0.83 ± 0.05) in the determination of speech laterality compared to all other models. The present study is a pioneer investigation into the determination of speech laterality via EEG signals with machine learning techniques, which, to our knowledge, has never been reported in the literature. Moreover, the classification results obtained in the study are promising and lead the way for subsequent studies though not practically feasible.
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Affiliation(s)
- Suat Toraman
- Firat University, Department of Informatics, 23119 Elazig, Turkey.
| | - Seda Arslan Tuncer
- Firat University, Department of Software Engineering, 23119 Elazig, Turkey.
| | - Ferhat Balgetir
- Firat University, Faculty of Medicine, 23119 Elazig, Turkey.
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20
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Wegrzyn M, Mertens M, Bien CG, Woermann FG, Labudda K. Quantifying the Confidence in fMRI-Based Language Lateralisation Through Laterality Index Deconstruction. Front Neurol 2019; 10:655. [PMID: 31275236 PMCID: PMC6594217 DOI: 10.3389/fneur.2019.00655] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 06/04/2019] [Indexed: 11/13/2022] Open
Abstract
In epilepsy patients, language lateralisation is an important part of the presurgical diagnostic process. Using task-based fMRI, language lateralisation can be determined by visual inspection of activity patterns or by quantifying the difference in left- and right-hemisphere activity using variations of a basic formula [(L-R)/(L+R)]. However, the values of this laterality index (LI) depend on the choice of activity thresholds and regions of interest. The diagnostic utility of the LI also depends on how its continuous values are translated into categorical decisions about a patient's language lateralisation. Here, we analysed fMRI data from 712 epilepsy patients who performed a verbal fluency task. Each fMRI data set was evaluated by a trained human rater as depicting left-sided, right-sided, or bilateral lateralisation or as being inconclusive. We used data-driven methods to define the activity thresholds and regions of interest used for LI computation and to define a classification scheme that allowed us to translate the LI values into categorical decisions. By deconstructing the LI into measures of laterality (L-R) and strength (L+R), we also modelled the relationship between activation strength and conclusiveness of a data set. In a held-out data set, predictions reached 91% correct when using only conclusive data and 82% when inconclusive data were included. Although only trained on human evaluations of fMRIs, the approach generalised to the prediction of language Wada test results, allowing for significant above-chance accuracies. Compared against different existing methods of LI-computation, our approach improved the identification and exclusion of inconclusive cases and ensured that decisions for the remaining data could be made with consistently high accuracies. We discuss how this approach can support clinicians in assessing fMRI data on a single-case level, deciding whether lateralisation can be determined with sufficient certainty or whether additional information is needed.
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Affiliation(s)
- Martin Wegrzyn
- Department of Psychology, Bielefeld University, Bielefeld, Germany
| | - Markus Mertens
- Bethel Epilepsy Center, Mara Hospital, Bielefeld, Germany
| | | | | | - Kirsten Labudda
- Department of Psychology, Bielefeld University, Bielefeld, Germany
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21
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Woodhead ZVJ, Bradshaw AR, Wilson AC, Thompson PA, Bishop DVM. Testing the unitary theory of language lateralization using functional transcranial Doppler sonography in adults. ROYAL SOCIETY OPEN SCIENCE 2019; 6:181801. [PMID: 31032035 PMCID: PMC6458414 DOI: 10.1098/rsos.181801] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 02/12/2019] [Indexed: 05/08/2023]
Abstract
Hemispheric dominance for language can vary from task to task, but it is unclear if this reflects error of measurement or independent lateralization of different language systems. We used functional transcranial Doppler sonography to assess language lateralization within the middle cerebral artery territory in 37 adults (seven left-handers) on six tasks, each given on two occasions. Tasks taxed different aspects of language function. A pre-registered structural equation analysis was used to compare models of means and covariances. For most people, a single lateralized factor explained most of the covariance between tasks. A minority, however, showed dissociation of asymmetry, giving a second factor. This was mostly derived from a receptive task, which was highly reliable but not lateralized. The results suggest that variation in the strength of language lateralization reflects true individual differences and not just error of measurement. The inclusion of several tasks in a laterality battery makes it easier to detect cases of atypical asymmetry.
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22
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You X, Zachery AN, Fanto E, Norato G, Germeyan SC, Emery EJ, Sepeta LN, Berl MM, Black CL, Wiggs E, Zaghloul K, Inati SK, Gaillard WD, Theodore WH. fMRI prediction of naming change after adult temporal lobe epilepsy surgery: Activation matters. Epilepsia 2019; 60:527-538. [PMID: 30740666 PMCID: PMC6401285 DOI: 10.1111/epi.14656] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 01/04/2019] [Accepted: 01/07/2019] [Indexed: 11/27/2022]
Abstract
OBJECTIVE We aimed to predict language deficits after epilepsy surgery. In addition to evaluating surgical factors examined previously, we determined the impact of the extent of functional magnetic resonance imaging (fMRI) activation that was resected on naming ability. METHOD Thirty-five adults (mean age 37.5 ± 10.9 years, 13 male) with temporal lobe epilepsy completed a preoperative fMRI auditory description decision task, which reliably activates frontal and temporal language networks. Patients underwent temporal lobe resections (20 left resection). The Boston Naming Test (BNT) was used to determine language functioning before and after surgery. Language dominance was determined for Broca and Wernicke area (WA) by calculating a laterality index following statistical parametric mapping processing. We used an innovative method to generate anatomic resection masks automatically from pre- and postoperative MRI tissue map comparison. This mask provided the following: (a) resection volume; (b) overlap between resection and preoperative activation; and (c) overlap between resection and WA. We examined postoperative language change predictors using stepwise linear regression. Predictors included parameters described above as well as age at seizure onset (ASO), preoperative BNT score, and resection side and its relationship to language dominance. RESULTS Seven of 35 adults had significant naming decline (6 dominant-side resections). The final regression model predicted 38% of the naming score change variance (adjusted r2 = 0.28, P = 0.012). The percentage of top 10% fMRI activation resected (P = 0.017) was the most significant contributor. Other factors in the model included WA LI, ASO, volume of WA resected, and WA LI absolute value (extent of laterality). SIGNIFICANCE Resection of fMRI activation during a word-definition decision task is an important factor for postoperative change in naming ability, along with other previously reported predictors. Currently, many centers establish language dominance using fMRI. Our results suggest that the amount of the top 10% of language fMRI activation in the intended resection area provides additional predictive power and should be considered when planning surgical resection.
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Affiliation(s)
- Xiaozhen You
- Clinical Epilepsy Section, National Institute of
Neurological Disorders and Stroke
- Children’s Research Institute, Children’s
National Hospital System
- Psychology, Georgetown University
| | - Ashley N. Zachery
- Clinical Epilepsy Section, National Institute of
Neurological Disorders and Stroke
- Children’s Research Institute, Children’s
National Hospital System
| | - Eleanor Fanto
- Clinical Epilepsy Section, National Institute of
Neurological Disorders and Stroke
- Children’s Research Institute, Children’s
National Hospital System
| | - Gina Norato
- Office of the Clinical Director, National Institute of
Neurological Disorders and Stroke
| | - Sierra C. Germeyan
- Clinical Epilepsy Section, National Institute of
Neurological Disorders and Stroke
| | - Eric J. Emery
- Clinical Epilepsy Section, National Institute of
Neurological Disorders and Stroke
- Children’s Research Institute, Children’s
National Hospital System
| | - Leigh N. Sepeta
- Clinical Epilepsy Section, National Institute of
Neurological Disorders and Stroke
- Children’s Research Institute, Children’s
National Hospital System
| | - Madison M. Berl
- Clinical Epilepsy Section, National Institute of
Neurological Disorders and Stroke
- Children’s Research Institute, Children’s
National Hospital System
| | - Chelsea L. Black
- Children’s Research Institute, Children’s
National Hospital System
| | - Edythe Wiggs
- Clinical Epilepsy Section, National Institute of
Neurological Disorders and Stroke
| | - Kareem Zaghloul
- Surgical Neurology Branch, National Institute of
Neurological Disorders and Stroke
| | - Sara K. Inati
- Office of the Clinical Director, National Institute of
Neurological Disorders and Stroke
| | - William D. Gaillard
- Clinical Epilepsy Section, National Institute of
Neurological Disorders and Stroke
- Children’s Research Institute, Children’s
National Hospital System
| | - William H. Theodore
- Clinical Epilepsy Section, National Institute of
Neurological Disorders and Stroke
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23
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Woodhead ZV, Rutherford HA, Bishop DV. Measurement of language laterality using functional transcranial Doppler ultrasound: a comparison of different tasks. Wellcome Open Res 2018; 3:104. [PMID: 30345386 PMCID: PMC6171558 DOI: 10.12688/wellcomeopenres.14720.2] [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] [Accepted: 10/11/2018] [Indexed: 11/14/2023] Open
Abstract
Background: Relative blood flow in the two middle cerebral arteries can be measured using functional transcranial Doppler sonography (fTCD) to give an index of lateralisation as participants perform a specific task. Language laterality has mostly been studied with fTCD using a word generation task, but it is not clear whether this is optimal. Methods: Using fTCD, we evaluated a sentence generation task that has shown good reliability and strong left lateralisation in fMRI. We interleaved trials of word generation, sentence generation and list generation and assessed agreement of these tasks in 31 participants (29 right-handers). Results: Although word generation and sentence generation both gave robust left-lateralisation, Bland-Altman analysis showed that these two methods were not equivalent. The comparison list generation task was not systematically lateralised, but nevertheless laterality indices (LIs) from this task were significantly correlated with the other two tasks. Subtracting list generation LI from sentence generation LI did not affect the strength of the laterality index. Conclusions: This was a pre-registered methodological study designed to explore novel approaches to optimising measurement of language lateralisation using fTCD. It confirmed that sentence generation gives robust left lateralisation in most people, but is not equivalent to the classic word generation task. Although list generation does not show left-lateralisation at the group level, the LI on this task was correlated with left-lateralised tasks. This suggests that word and sentence generation involve adding a constant directional bias to an underlying continuum of laterality that is reliable in individuals but not biased in either direction. In future research we suggest that consistency of laterality across tasks might have more functional significance than strength or direction of laterality on any one task.
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Affiliation(s)
- Zoe V.J. Woodhead
- Department of Experimental Psychology, University of Oxford, Oxford, UK
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24
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Audrain S, Barnett AJ, McAndrews MP. Language network measures at rest indicate individual differences in naming decline after anterior temporal lobe resection. Hum Brain Mapp 2018; 39:4404-4419. [PMID: 29956405 DOI: 10.1002/hbm.24281] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 06/03/2018] [Accepted: 06/06/2018] [Indexed: 02/03/2023] Open
Abstract
While anterior temporal lobe (ATL) resection is an effective treatment for temporal lobe epilepsy, surgery on the dominant hemisphere is associated with variable decline in confrontation naming. Accurate prediction of naming impairment is critical to inform clinical decision making, and while there has been some degree of success using task-based functional MRI (fMRI) paradigms, there remains a growing interest in the predictive utility of resting-state connectivity as it allows for relatively shorter scans with low task demands. Our objective was to assess the relationship between measures of preoperative resting-state connectivity and postoperative naming change in patients following left ATL resection. We compared the resting language network connectivity of each patient to a normative healthy control template using a novel measure called "matrix similarity," and found that patients with more abnormal global language-network connectivity-particularly of regions spared from surgery-showed greater postoperative naming decline than those with normative patterns of connectivity. When we interrogated the degree centrality of to-be-resected regions in a more targeted approach of the pathological temporal lobe, we found that greater functional integration of those regions with the rest of the language network at rest was related to greater decline in naming following surgery. Finally, we found that matrix similarity was a better predictor of postoperative outcome than degree within to-be-resected regions, network clustering, modularity, and language task fMRI laterality. We provide some of the first evidence that using this novel measure, a relatively short preoperative resting scan can be exploited to inform naming ability following ATL resection.
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Affiliation(s)
- Samantha Audrain
- Brain Imaging and Behavior: Systems Neuroscience, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Department of Psychology, University of Toronto, Toronto, Ontario, Canada
| | - Alexander J Barnett
- Brain Imaging and Behavior: Systems Neuroscience, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Department of Psychology, University of Toronto, Toronto, Ontario, Canada
| | - Mary P McAndrews
- Brain Imaging and Behavior: Systems Neuroscience, Krembil Research Institute, University Health Network, Toronto, Ontario, Canada.,Department of Psychology, University of Toronto, Toronto, Ontario, Canada
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Bradshaw AR, Bishop DVM, Woodhead ZVJ. Methodological considerations in assessment of language lateralisation with fMRI: a systematic review. PeerJ 2017; 5:e3557. [PMID: 28713656 PMCID: PMC5508809 DOI: 10.7717/peerj.3557] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 06/18/2017] [Indexed: 11/20/2022] Open
Abstract
The involvement of the right and left hemispheres in mediating language functions has been measured in a variety of ways over the centuries since the relative dominance of the left hemisphere was first known. Functional magnetic resonance imaging (fMRI) presents a useful non-invasive method of assessing lateralisation that is being increasingly used in clinical practice and research. However, the methods used in the fMRI laterality literature currently are highly variable, making systematic comparisons across studies difficult. Here we consider the different methods of quantifying and classifying laterality that have been used in fMRI studies since 2000, with the aim of determining which give the most robust and reliable measurement. Recommendations are made with a view to informing future research to increase standardisation in fMRI laterality protocols. In particular, the findings reinforce the importance of threshold-independent methods for calculating laterality indices, and the benefits of assessing heterogeneity of language laterality across multiple regions of interest and tasks. This systematic review was registered as a protocol on Open Science Framework: https://osf.io/hyvc4/.
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Affiliation(s)
- Abigail R Bradshaw
- Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | - Dorothy V M Bishop
- Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | - Zoe V J Woodhead
- Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
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Corballis MC. The Evolution of Lateralized Brain Circuits. Front Psychol 2017; 8:1021. [PMID: 28670296 PMCID: PMC5472687 DOI: 10.3389/fpsyg.2017.01021] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 06/02/2017] [Indexed: 01/06/2023] Open
Abstract
In the vast clade of animals known as the bilateria, cerebral and behavioral asymmetries emerge against the backdrop of bilateral symmetry, with a functional trade-off between the two. Asymmetries can lead to more efficient processing and packaging of internal structures, but at the expense of efficient adaptation to a natural world without systematic left-right bias. Asymmetries may arise through the fissioning of ancestral structures that are largely symmetrical, creating new circuits. In humans these may include asymmetrical adaptations to language and manufacture, and as one or other hemisphere gains dominance for functions that were previously represented bilaterally. This is best illustrated in the evolution of such functions as language and tool manufacture in humans, which may derive from the mirror-neuron system in primates, but similar principles probably apply to the many other asymmetries now evident in a wide range of animals. Asymmetries arise in largely independent manner with multi-genetic sources, rather than as a single over-riding principle.
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