1
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Aabedi AA, Young JS, Chang EF, Berger MS, Hervey-Jumper SL. Involvement of White Matter Language Tracts in Glioma: Clinical Implications, Operative Management, and Functional Recovery After Injury. Front Neurosci 2022; 16:932478. [PMID: 35898410 PMCID: PMC9309688 DOI: 10.3389/fnins.2022.932478] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 06/14/2022] [Indexed: 11/13/2022] Open
Abstract
To achieve optimal survival and quality of life outcomes in patients with glioma, the extent of tumor resection must be maximized without causing injury to eloquent structures. Preservation of language function is of particular importance to patients and requires careful mapping to reveal the locations of cortical language hubs and their structural and functional connections. Within this language network, accurate mapping of eloquent white matter tracts is critical, given the high risk of permanent neurological impairment if they are injured during surgery. In this review, we start by describing the clinical implications of gliomas involving white matter language tracts. Next, we highlight the advantages and limitations of methods commonly used to identify these tracts during surgery including structural imaging techniques, functional imaging, non-invasive stimulation, and finally, awake craniotomy. We provide a rationale for combining these complementary techniques as part of a multimodal mapping paradigm to optimize postoperative language outcomes. Next, we review local and long-range adaptations that take place as the language network undergoes remodeling after tumor growth and surgical resection. We discuss the probable cellular mechanisms underlying this plasticity with emphasis on the white matter, which until recently was thought to have a limited role in adults. Finally, we provide an overview of emerging developments in targeting the glioma-neuronal network interface to achieve better disease control and promote recovery after injury.
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Affiliation(s)
| | | | | | | | - Shawn L. Hervey-Jumper
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, United States
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2
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de Tommaso M, Betti V, Bocci T, Bolognini N, Di Russo F, Fattapposta F, Ferri R, Invitto S, Koch G, Miniussi C, Piccione F, Ragazzoni A, Sartucci F, Rossi S, Valeriani M. Pearl and pitfalls in brain functional analysis by event-related potentials: a narrative review by the Italian Psychophysiology and Cognitive Neuroscience Society on methodological limits and clinical reliability-part II. Neurol Sci 2020; 41:3503-3515. [PMID: 32683566 DOI: 10.1007/s10072-020-04527-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Accepted: 06/21/2020] [Indexed: 12/13/2022]
Abstract
This review focuses on new and/or less standardized event-related potentials methods, in order to improve their knowledge for future clinical applications. The olfactory event-related potentials (OERPs) assess the olfactory functions in time domain, with potential utility in anosmia and degenerative diseases. The transcranial magnetic stimulation-electroencephalography (TMS-EEG) could support the investigation of the intracerebral connections with very high temporal discrimination. Its application in the diagnosis of disorders of consciousness has achieved recent confirmation. Magnetoencephalography (MEG) and event-related fields (ERF) could improve spatial accuracy of scalp signals, with potential large application in pre-surgical study of epileptic patients. Although these techniques have methodological limits, such as high inter- and intraindividual variability and high costs, their diffusion among researchers and clinicians is hopeful, pending their standardization.
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Affiliation(s)
- Marina de Tommaso
- Applied Neurophysiology and Pain Unit-AnpLab-University of Bari Aldo Moro, Bari, Italy
| | - Viviana Betti
- Department of Psychology, Sapienza University of Rome, Rome, Italy.,Fondazione Santa Lucia, Istituto Di Ricovero e Cura a Carattere Scientifico, Rome, Italy
| | - Tommaso Bocci
- Dipartimento di Scienze della Salute, University of Milano, Milan, Italy
| | - Nadia Bolognini
- Department of Psychology & NeuroMi, University of Milano Bicocca, Milan, Italy.,Laboratory of Neuropsychology, IRCCS Istituto Auxologico, Milan, Italy
| | - Francesco Di Russo
- Dept. of Movement, Human and Health Sciences, University of Rome "Foro Italico", Rome, Italy
| | | | | | - Sara Invitto
- INSPIRE - Laboratory of Cognitive and Psychophysiological Olfactory Processes, University of Salento, Lecce, Italy
| | - Giacomo Koch
- Fondazione Santa Lucia, Istituto Di Ricovero e Cura a Carattere Scientifico, Rome, Italy.,Neuroscience Department, Policlinico Tor Vergata, Rome, Italy
| | - Carlo Miniussi
- Center for Mind/Brain Sciences - CIMeC, University of Trento, Rovereto, Italy.,Cognitive Neuroscience Section, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Francesco Piccione
- Brain Imaging and Neural Dynamics Research Group, IRCCS San Camillo Hospital, Venice, Italy
| | - Aldo Ragazzoni
- Unit of Neurology and Clinical Neurophysiology, Fondazione PAS, Scandicci, Florence, Italy
| | - Ferdinando Sartucci
- Section of Neurophysiopathology, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.,CNR Institute of Neuroscience, Pisa, Italy
| | - Simone Rossi
- Department of Medicine, Surgery and Neuroscience Siena Brain Investigation and Neuromodulation LAb (SI-BIN Lab), University of Siena, Siena, Italy
| | - Massimiliano Valeriani
- Neurology Unit, Bambino Gesù Hospital, Rome, Italy. .,Center for Sensory-Motor Interaction, Aalborg University, Aalborg, Denmark.
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3
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Balter S, Lin G, Leyden KM, Paul BM, McDonald CR. Neuroimaging correlates of language network impairment and reorganization in temporal lobe epilepsy. BRAIN AND LANGUAGE 2019; 193:31-44. [PMID: 27393391 PMCID: PMC5215985 DOI: 10.1016/j.bandl.2016.06.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 02/27/2016] [Accepted: 06/15/2016] [Indexed: 06/02/2023]
Abstract
Advanced, noninvasive imaging has revolutionized our understanding of language networks in the brain and is reshaping our approach to the presurgical evaluation of patients with epilepsy. Functional magnetic resonance imaging (fMRI) has had the greatest impact, unveiling the complexity of language organization and reorganization in patients with epilepsy both pre- and postoperatively, while volumetric MRI and diffusion tensor imaging have led to a greater appreciation of structural and microstructural correlates of language dysfunction in different epilepsy syndromes. In this article, we review recent literature describing how unimodal and multimodal imaging has advanced our knowledge of language networks and their plasticity in epilepsy, with a focus on the most frequently studied epilepsy syndrome in adults, temporal lobe epilepsy (TLE). We also describe how new analytic techniques (i.e., graph theory) are leading to a refined characterization of abnormal brain connectivity, and how subject-specific imaging profiles combined with clinical data may enhance the prediction of both seizure and language outcomes following surgical interventions.
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Affiliation(s)
- S Balter
- Department of Neurology, University of California, San Francisco, CA, United States; UCSF Comprehensive Epilepsy Center, United States
| | - G Lin
- Palo Alto University, Palo Alto, CA, United States
| | - K M Leyden
- Multimodal Imaging Laboratory, University of California, San Diego, CA, United States
| | - B M Paul
- Department of Neurology, University of California, San Francisco, CA, United States; UCSF Comprehensive Epilepsy Center, United States
| | - C R McDonald
- Multimodal Imaging Laboratory, University of California, San Diego, CA, United States; Department of Psychiatry, University of California, San Diego, CA, United States.
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4
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Traut T, Sardesh N, Bulubas L, Findlay A, Honma SM, Mizuiri D, Berger MS, Hinkley LB, Nagarajan SS, Tarapore PE. MEG imaging of recurrent gliomas reveals functional plasticity of hemispheric language specialization. Hum Brain Mapp 2018; 40:1082-1092. [PMID: 30549134 DOI: 10.1002/hbm.24430] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 10/04/2018] [Accepted: 10/05/2018] [Indexed: 11/09/2022] Open
Abstract
In patients with gliomas, changes in hemispheric specialization for language determined by magnetoencephalography (MEG) were analyzed to elucidate the impact of treatment and tumor recurrence on language networks. Demonstration of reorganization of language networks in these patients has significant implications on the prevention of postoperative functional loss and recovery. Whole-brain activity during an auditory verb generation task was estimated from MEG recordings in a group of 73 patients with recurrent gliomas. Hemisphere of language dominance was estimated using the language laterality index (LI), a measure derived from the task. The initial scan was performed prior to resection; patients subsequently underwent surgery and adjuvant treatment. A second scan was performed upon recurrence prior to repeat resection. The relationship between the shift in LI between scans and demographics, anatomic location, pathology, and adjuvant treatment was analyzed. Laterality shifts were observed between scans; the median percent change was 29.1% across all patients. Laterality shift magnitude and relative direction were associated with the initial position of language dominance; patients with increased lateralization experienced greater shifts than those presenting more bilateral representation. A change in LI from left or right to bilateral (or vice versa) occurred in 23.3% of patients; complete switch occurred in 5.5% of patients. Patients with tumors within the language-dominant hemisphere experienced significantly greater shifts than those with contralateral tumors. The majority of patients with glioma experience shifts in language network organization over time which correlate with the relative position of language lateralization and tumor location.
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Affiliation(s)
- Tavish Traut
- Biomagnetic Imaging Lab, Department of Radiology and Biomedical Imaging, University of California, San Francisco (UCSF), San Francisco, California
| | - Nina Sardesh
- Biomagnetic Imaging Lab, Department of Radiology and Biomedical Imaging, University of California, San Francisco (UCSF), San Francisco, California
| | - Lucia Bulubas
- Biomagnetic Imaging Lab, Department of Radiology and Biomedical Imaging, University of California, San Francisco (UCSF), San Francisco, California.,Department of Neurosurgery, Klinikum Rechts der Isar, TU München, Munich, Germany.,TUM-Neuroimaging Center, Klinikum Rechts der Isar, TU München, Munich, Germany
| | - Anne Findlay
- Biomagnetic Imaging Lab, Department of Radiology and Biomedical Imaging, University of California, San Francisco (UCSF), San Francisco, California
| | - Susanne M Honma
- Biomagnetic Imaging Lab, Department of Radiology and Biomedical Imaging, University of California, San Francisco (UCSF), San Francisco, California
| | - Danielle Mizuiri
- Biomagnetic Imaging Lab, Department of Radiology and Biomedical Imaging, University of California, San Francisco (UCSF), San Francisco, California
| | - Mitchel S Berger
- Department of Neurological Surgery, University of California, San Francisco (UCSF), San Francisco, California
| | - Leighton B Hinkley
- Biomagnetic Imaging Lab, Department of Radiology and Biomedical Imaging, University of California, San Francisco (UCSF), San Francisco, California
| | - Srikantan S Nagarajan
- Biomagnetic Imaging Lab, Department of Radiology and Biomedical Imaging, University of California, San Francisco (UCSF), San Francisco, California
| | - Phiroz E Tarapore
- Biomagnetic Imaging Lab, Department of Radiology and Biomedical Imaging, University of California, San Francisco (UCSF), San Francisco, California.,Department of Neurological Surgery, University of California, San Francisco (UCSF), San Francisco, California
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5
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Seedorff M, Oleson J, McMurray B. Detecting when timeseries differ: Using the Bootstrapped Differences of Timeseries (BDOTS) to analyze Visual World Paradigm data (and more). JOURNAL OF MEMORY AND LANGUAGE 2018; 102:55-67. [PMID: 32863563 PMCID: PMC7450631 DOI: 10.1016/j.jml.2018.05.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In the last decades, major advances in the language sciences have been built on real-time measures of language and cognitive processing, measures like mouse-tracking, event related potentials and eye-tracking in the visual world paradigm. These measures yield densely sampled timeseries that can be highly revealing of the dynamics of cognitive processing. However, despite these methodological advances, existing statistical approaches for timeseries analyses have often lagged behind. Here, we present a new statistical approach, the Bootstrapped Differences of Timeseries (BDOTS), that can estimate the precise timewindow at which two timeseries differ. BDOTS makes minimal assumptions about the error distribution, uses a custom family-wise error correction, and can flexibly be adapted to a variety of applications. This manuscript presents the theoretical basis of this approach, describes implementational issues (in the associated R package), and illustrates this technique with an analysis of an existing dataset. Pitfalls and hazards are also discussed, along with suggestions for reporting in the literature.
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Affiliation(s)
| | | | - Bob McMurray
- Dept. of Psychological and Brain Sciences, Dept. of Communication Sciences and Disorders, Dept. of Linguistics, University of Iowa
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6
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Magnetoencephalography: Clinical and Research Practices. Brain Sci 2018; 8:brainsci8080157. [PMID: 30126121 PMCID: PMC6120049 DOI: 10.3390/brainsci8080157] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 08/07/2018] [Accepted: 08/11/2018] [Indexed: 11/25/2022] Open
Abstract
Magnetoencephalography (MEG) is a neurophysiological technique that detects the magnetic fields associated with brain activity. Synthetic aperture magnetometry (SAM), a MEG magnetic source imaging technique, can be used to construct both detailed maps of global brain activity as well as virtual electrode signals, which provide information that is similar to invasive electrode recordings. This innovative approach has demonstrated utility in both clinical and research settings. For individuals with epilepsy, MEG provides valuable, nonredundant information. MEG accurately localizes the irritative zone associated with interictal spikes, often detecting epileptiform activity other methods cannot, and may give localizing information when other methods fail. These capabilities potentially greatly increase the population eligible for epilepsy surgery and improve planning for those undergoing surgery. MEG methods can be readily adapted to research settings, allowing noninvasive assessment of whole brain neurophysiological activity, with a theoretical spatial range down to submillimeter voxels, and in both humans and nonhuman primates. The combination of clinical and research activities with MEG offers a unique opportunity to advance translational research from bench to bedside and back.
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7
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Pastori C, Francione S, Pelle F, de Curtis M, Gnatkovsky V. Fluency tasks generate beta-gamma activity in language-related cortical areas of patients during stereo-EEG monitoring. BRAIN AND LANGUAGE 2016; 163:50-56. [PMID: 27684988 DOI: 10.1016/j.bandl.2016.09.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 09/07/2016] [Accepted: 09/12/2016] [Indexed: 06/06/2023]
Abstract
A quantitative method was developed to map cortical areas responsive to cognitive tasks during intracerebral stereo-EEG recording sessions in drug-resistant patients candidate for epilepsy surgery. Frequency power changes were evaluated with a computer-assisted analysis in 7 patients during phonemic fluency tasks. All patients were right-handed and were explored with depth electrodes in the dominant frontal lobe. We demonstrate that fluency tasks enhance beta-gamma frequencies and reduce background activities in language network regions of the dominant hemisphere. Non-reproducible changes were observed in other explored brain areas during cognitive tests execution.
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Affiliation(s)
- Chiara Pastori
- Unit of Epileptology and Experimental Neurophysiology, Fondazione Istituto Neurologico Carlo Besta, Milano, Italy
| | - Stefano Francione
- Claudio Munari Epilepsy Surgery Center, Ospedale Niguarda, Milano, Italy
| | - Federica Pelle
- Claudio Munari Epilepsy Surgery Center, Ospedale Niguarda, Milano, Italy
| | - Marco de Curtis
- Unit of Epileptology and Experimental Neurophysiology, Fondazione Istituto Neurologico Carlo Besta, Milano, Italy
| | - Vadym Gnatkovsky
- Unit of Epileptology and Experimental Neurophysiology, Fondazione Istituto Neurologico Carlo Besta, Milano, Italy.
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8
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Sollmann N, Hauck T, Tussis L, Ille S, Maurer S, Boeckh-Behrens T, Ringel F, Meyer B, Krieg SM. Results on the spatial resolution of repetitive transcranial magnetic stimulation for cortical language mapping during object naming in healthy subjects. BMC Neurosci 2016; 17:67. [PMID: 27776478 PMCID: PMC5078936 DOI: 10.1186/s12868-016-0305-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 10/19/2016] [Indexed: 11/20/2022] Open
Abstract
Background The spatial resolution of repetitive navigated transcranial magnetic stimulation (rTMS) for language mapping is largely unknown. Thus, to determine a minimum spatial resolution of rTMS for language mapping, we evaluated the mapping sessions derived from 19 healthy volunteers for cortical hotspots of no-response errors. Then, the distances between hotspots (stimulation points with a high error rate) and adjacent mapping points (stimulation points with low error rates) were evaluated. Results Mean distance values of 13.8 ± 6.4 mm (from hotspots to ventral points, range 0.7–30.7 mm), 10.8 ± 4.8 mm (from hotspots to dorsal points, range 2.0–26.5 mm), 16.6 ± 4.8 mm (from hotspots to apical points, range 0.9–27.5 mm), and 13.8 ± 4.3 mm (from hotspots to caudal points, range 2.0–24.2 mm) were measured. Conclusions According to the results, the minimum spatial resolution of rTMS should principally allow for the identification of a particular gyrus, and according to the literature, it is in good accordance with the spatial resolution of direct cortical stimulation (DCS). Since measurement was performed between hotspots and adjacent mapping points and not on a finer-grained basis, we only refer to a minimum spatial resolution. Furthermore, refinement of our results within the scope of a prospective study combining rTMS and DCS for resolution measurement during language mapping should be the next step.
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Affiliation(s)
- Nico Sollmann
- Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany.,TUM-Neuroimaging Center, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany
| | - Theresa Hauck
- Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany.,TUM-Neuroimaging Center, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany
| | - Lorena Tussis
- Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany
| | - Sebastian Ille
- Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany.,TUM-Neuroimaging Center, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany
| | - Stefanie Maurer
- Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany.,TUM-Neuroimaging Center, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany
| | - Tobias Boeckh-Behrens
- Section of Neuroradiology, Department of Radiology, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany
| | - Florian Ringel
- Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany
| | - Bernhard Meyer
- Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany
| | - Sandro M Krieg
- Department of Neurosurgery, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany. .,TUM-Neuroimaging Center, Klinikum rechts der Isar, Technische Universität München, Ismaninger Str. 22, 81675, Munich, Germany.
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9
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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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10
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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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11
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Magnetoencephalography in the Preoperative Evaluation for Epilepsy Surgery. Curr Neurol Neurosci Rep 2014; 14:446. [DOI: 10.1007/s11910-014-0446-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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12
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Choudhri AF, Narayana S, Rezaie R, Whitehead MT, McAfee SS, Wheless JW, Boop FA, Papanicolaou AC. Same day tri-modality functional brain mapping prior to resection of a lesion involving eloquent cortex: technical feasibility. Neuroradiol J 2013; 26:548-54. [PMID: 24199815 DOI: 10.1177/197140091302600508] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 10/09/2013] [Indexed: 11/15/2022] Open
Abstract
Non-invasive functional evaluation of the brain complements structural MRI imaging and has largely supplanted invasive techniques such as awake craniotomy. Techniques used for functional mapping of the brain include BOLD-functional MRI (fMRI), magnetoencephalography (MEG), and transcranial magnetic stimulation (TMS). We describe the case of a right-handed patient with a lesion centered in the left inferior perirolandic cortex who underwent fMRI, MEG, and TMS on a single day to facilitate maximal lesion resection while preserving eloquent cortex and eloquent white matter tracts.
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Affiliation(s)
- Asim F Choudhri
- Department of Radiology, Department of Pediatrics, Division of Clinical Neurosciences, Department of Neurosurgery, Department of Ophthalmology, Division of Neurology University of Tennessee, Health Science Center; Memphis, TN, USA - Le Bonheur Neuroscience Institute, Le Bonheur Children's Hospital; Memphis, TN, USA -
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13
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Reconstructing spatially extended brain sources via enforcing multiple transform sparseness. Neuroimage 2013; 86:280-93. [PMID: 24103850 DOI: 10.1016/j.neuroimage.2013.09.070] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 09/24/2013] [Accepted: 09/28/2013] [Indexed: 11/22/2022] Open
Abstract
Accurate estimation of location and extent of neuronal sources from EEG/MEG remain challenging. In the present study, a new source imaging method, i.e. variation and wavelet based sparse source imaging (VW-SSI), is proposed to better estimate cortical source locations and extents. VW-SSI utilizes the L1-norm regularization method with the enforcement of transform sparseness in both variation and wavelet domains. The performance of the proposed method is assessed by both simulated and experimental MEG data, obtained from a language task and a motor task. Compared to L2-norm regularizations, VW-SSI demonstrates significantly improved capability in reconstructing multiple extended cortical sources with less spatial blurredness and less localization error. With the use of transform sparseness, VW-SSI overcomes the over-focused problem in classic SSI methods. With the use of two transformations, VW-SSI further indicates significantly better performance in estimating MEG source locations and extents than other SSI methods with single transformations. The present experimental results indicate that VW-SSI can successfully estimate neural sources (and their spatial coverage) located in close areas while responsible for different functions, i.e. temporal cortical sources for auditory and language processing, and sources on the pre-bank and post-bank of the central sulcus. Meantime, all other methods investigated in the present study fail to recover these phenomena. Precise estimation of cortical source locations and extents from EEG/MEG is of significance for applications in neuroscience and neurology.
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14
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Braeutigam S. Magnetoencephalography: fundamentals and established and emerging clinical applications in radiology. ISRN RADIOLOGY 2013; 2013:529463. [PMID: 24967282 PMCID: PMC4045536 DOI: 10.5402/2013/529463] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 07/03/2013] [Indexed: 12/17/2022]
Abstract
Magnetoencephalography is a noninvasive, fast, and patient friendly technique for recording brain activity. It is increasingly available and is regarded as one of the most modern imaging tools available to radiologists. The dominant clinical use of this technology currently centers on two, partly overlapping areas, namely, localizing the regions from which epileptic seizures originate, and identifying regions of normal brain function in patients preparing to undergo brain surgery. As a consequence, many radiologists may not yet be familiar with this technique. This review provides an introduction to magnetoencephalography, discusses relevant analytical techniques, and presents recent developments in established and emerging clinical applications such as pervasive developmental disorders. Although the role of magnetoencephalography in diagnosis, prognosis, and patient treatment is still limited, it is argued that this technology is exquisitely capable of contributing indispensable information about brain dynamics not easily obtained with other modalities. This, it is believed, will make this technology an important clinical tool for a wide range of disorders in the future.
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Affiliation(s)
- Sven Braeutigam
- Oxford Centre for Human Brain Activity, Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford OX3 7JX, UK
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15
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Liao K, Zhu M, Ding L. A new wavelet transform to sparsely represent cortical current densities for EEG/MEG inverse problems. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2013; 111:376-388. [PMID: 23706527 DOI: 10.1016/j.cmpb.2013.04.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 02/05/2013] [Accepted: 04/22/2013] [Indexed: 06/02/2023]
Abstract
The present study investigated the use of transform sparseness of cortical current density on human brain surface to improve electroencephalography/magnetoencephalography (EEG/MEG) inverse solutions. Transform sparseness was assessed by evaluating compressibility of cortical current densities in transform domains. To do that, a structure compression method from computer graphics was first adopted to compress cortical surface structure, either regular or irregular, into hierarchical multi-resolution meshes. Then, a new face-based wavelet method based on generated multi-resolution meshes was proposed to compress current density functions defined on cortical surfaces. Twelve cortical surface models were built by three EEG/MEG softwares and their structural compressibility was evaluated and compared by the proposed method. Monte Carlo simulations were implemented to evaluate the performance of the proposed wavelet method in compressing various cortical current density distributions as compared to other two available vertex-based wavelet methods. The present results indicate that the face-based wavelet method can achieve higher transform sparseness than vertex-based wavelet methods. Furthermore, basis functions from the face-based wavelet method have lower coherence against typical EEG and MEG measurement systems than vertex-based wavelet methods. Both high transform sparseness and low coherent measurements suggest that the proposed face-based wavelet method can improve the performance of L1-norm regularized EEG/MEG inverse solutions, which was further demonstrated in simulations and experimental setups using MEG data. Thus, this new transform on complicated cortical structure is promising to significantly advance EEG/MEG inverse source imaging technologies.
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Affiliation(s)
- Ke Liao
- School of Electrical and Computer Engineering, University of Oklahoma, Norman, OK, USA
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16
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Rethinking clinical language mapping approaches: discordant receptive and expressive hemispheric language dominance in epilepsy surgery candidates. J Clin Neurophysiol 2011; 28:278-88. [PMID: 21633253 DOI: 10.1097/wnp.0b013e31821c321d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Neuroimaging studies have shed light on cortical language organization, with findings implicating the left and right temporal lobes in speech processing converging to a left-dominant pattern. Findings highlight the fact that the state of theoretical language knowledge is ahead of current clinical language mapping methods, motivating a rethinking of these approaches. The authors used magnetoencephalography and multiple tasks in seven candidates for resective epilepsy surgery to investigate language organization. The authors scanned 12 control subjects to investigate the time course of bilateral receptive speech processes. Laterality indices were calculated for left and right hemisphere late fields ∼150 to 400 milliseconds. The authors report that (1) in healthy adults, speech processes activated superior temporal regions bilaterally converging to a left-dominant pattern, (2) in four of six patients, this was reversed, with bilateral processing converging to a right-dominant pattern, and (3) in three of four of these patients, receptive and expressive language processes were laterally discordant. Results provide evidence that receptive and expressive language may have divergent hemispheric dominance. Right-sided receptive language dominance in epilepsy patients emphasizes the need to assess both receptive and expressive language. Findings indicate that it is critical to use multiple tasks tapping separable aspects of language function to provide sensitive and specific estimates of language localization in surgical patients.
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Frye RE, Liederman J, Hasan KM, Lincoln A, Malmberg B, McLean J, Papanicolaou A. Diffusion tensor quantification of the relations between microstructural and macrostructural indices of white matter and reading. Hum Brain Mapp 2011; 32:1220-1235. [PMID: 20665719 PMCID: PMC6869925 DOI: 10.1002/hbm.21103++++] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Revised: 04/18/2010] [Accepted: 05/05/2010] [Indexed: 05/21/2023] Open
Abstract
Few researchers agree about the relationship between fronto-temporo-parietal white matter microstructure and reading skills. Unlike many previous reports, which only measured fractional anisotropy, we have also measured macroscopic volume (regional white matter tract volume) and three microstructural indices (axial, radial, and mean diffusivity) to increase interpretability of our findings. We examined the reading-related skills and white matter structure in 10 adolescents and adults with a history of poor reading and 20 age-matched typical readers. We applied a diffusion tensor imaging atlas-based algorithm to major white matter pathways. The relation of white matter structural indices to reading group, hemisphere, and reading-related skill was analyzed using linear models. White matter microstructural indices were related to performance on a sublexical decoding task, but the relations between particular microstructural indices and sublexical decoding ability and reading group were different for association (i.e., cortical-cortical) and projection (i.e., subcortical-cortical) white matter pathways. Changes in projection pathways were consistent with alterations in white matter organization and axonal size, whereas changes in association pathways were consistent with alternations in pathway complexity. Changes in macrostructure paralleled changes in microstructure. We conclude that the relations between several microstructural indices and factors related to reading ability are different for association and projection pathways.
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Affiliation(s)
- Richard E Frye
- Division of Child and Adolescent Neurology, Department of Pediatrics, University of Texas Health Science Center, 7000 Fannin, Houston, TX 77030, USA.
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Alarcón G, Agirre-Arrizubieta Z. Magnetoencephalography in epilepsy: Is it time for EMEG? Clin Neurophysiol 2011; 122:1282-3. [DOI: 10.1016/j.clinph.2010.12.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Accepted: 12/23/2010] [Indexed: 10/18/2022]
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19
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Stefan H, Rampp S, Knowlton RC. Magnetoencephalography adds to the surgical evaluation process. Epilepsy Behav 2011; 20:172-7. [PMID: 20934391 DOI: 10.1016/j.yebeh.2010.09.011] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Accepted: 09/08/2010] [Indexed: 11/25/2022]
Abstract
Summarizing the podium discussion at the AES 2009, strengths and limitations of magnetoencephalography (MEG) are discussed with regard to basic methodological and clinical aspects in routine screening and presurgical evaluation of patients with epilepsies. Current literature and example cases are used to illustrate MEG contribution to clinical decision making, specifically whether a patient with pharmacoresistant epilepsy can move forward to epilepsy surgery. The main conclusion is that the largest role of MEG, as presently performed in the clinical environment, is to increase the number of patients who can go on to surgery, while it should not be used to deny surgery to any patient.
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Affiliation(s)
- H Stefan
- Epilepsy Center, Neurological Clinic, University Hospital Erlangen-Nuremberg at Erlangen, Erlangen, Germany.
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Abstract
Medically refractory focal epilepsy is potentially curable by surgery. This Review considers the application of recent advances in structural and functional brain imaging to increase the number of patients with epilepsy who are treated surgically, and to reduce the risk of complications arising from such intervention. Current optimal MRI of brain structure can identify previously undetectable lesions, with voxel-based and quantitative analyses further increasing the diagnostic yield. If MRI proves unremarkable, PET (with (18)F-fluorodeoxyglucose) and single-photon emission CT of ictal-interictal cerebral blood flow might identify the brain region that contains the epileptic focus. Magnetoencephalography plus simultaneous EEG and functional MRI can map the location of interictal epileptic discharges, thereby facilitating placement of intracranial recording electrodes to define the site of seizure onset. Functional MRI can also lateralize language and localize primary motor, somatosensory and language areas, and shows promise for predicting the effects of temporal lobe resection on memory. Tractography can visualize the main cerebral white matter tracts, thereby predicting and reducing surgery risk. Currently, displays of the optic radiation and pyramidal tracts are the most relevant for epilepsy surgery. Reliable integration of structural and functional data into surgical image-guidance systems is being pursued, and promises safer neurosurgery for epilepsy in the future.
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Affiliation(s)
- John S Duncan
- National Society for Epilepsy, Department of Clinical and Experimental Epilepsy, University College London Institute of Neurology, Queen Square, London, UK.
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Frye RE, Liederman J, Hasan KM, Lincoln A, Malmberg B, McLean J, Papanicolaou A. Diffusion tensor quantification of the relations between microstructural and macrostructural indices of white matter and reading. Hum Brain Mapp 2010; 32:1220-35. [PMID: 20665719 DOI: 10.1002/hbm.21103] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Revised: 04/18/2010] [Accepted: 05/05/2010] [Indexed: 11/12/2022] Open
Abstract
Few researchers agree about the relationship between fronto-temporo-parietal white matter microstructure and reading skills. Unlike many previous reports, which only measured fractional anisotropy, we have also measured macroscopic volume (regional white matter tract volume) and three microstructural indices (axial, radial, and mean diffusivity) to increase interpretability of our findings. We examined the reading-related skills and white matter structure in 10 adolescents and adults with a history of poor reading and 20 age-matched typical readers. We applied a diffusion tensor imaging atlas-based algorithm to major white matter pathways. The relation of white matter structural indices to reading group, hemisphere, and reading-related skill was analyzed using linear models. White matter microstructural indices were related to performance on a sublexical decoding task, but the relations between particular microstructural indices and sublexical decoding ability and reading group were different for association (i.e., cortical-cortical) and projection (i.e., subcortical-cortical) white matter pathways. Changes in projection pathways were consistent with alterations in white matter organization and axonal size, whereas changes in association pathways were consistent with alternations in pathway complexity. Changes in macrostructure paralleled changes in microstructure. We conclude that the relations between several microstructural indices and factors related to reading ability are different for association and projection pathways.
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Affiliation(s)
- Richard E Frye
- Division of Child and Adolescent Neurology, Department of Pediatrics, University of Texas Health Science Center, 7000 Fannin, Houston, TX 77030, USA.
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22
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Monahan PJ, Idsardi WJ. Auditory Sensitivity to Formant Ratios:Toward an Account of Vowel Normalization. LANGUAGE AND COGNITIVE PROCESSES 2010; 25:808-839. [PMID: 20606713 PMCID: PMC2893733 DOI: 10.1080/01690965.2010.490047] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
A long-standing question in speech perception research is how do listeners extract linguistic content from a highly variable acoustic input. In the domain of vowel perception, formant ratios, or the calculation of relative bark differences between vowel formants, have been a sporadically proposed solution. We propose a novel formant ratio algorithm in which the first (F1) and second (F2) formants are compared against the third formant (F3). Results from two magnetoencephelographic (MEG) experiments are presented that suggest auditory cortex is sensitive to formant ratios. Our findings also demonstrate that the perceptual system shows heightened sensitivity to formant ratios for tokens located in more crowded regions of the vowel space. Additionally, we present statistical evidence that this algorithm eliminates speaker-dependent variation based on age and gender from vowel productions. We conclude that these results present an impetus to reconsider formant ratios as a legitimate mechanistic component in the solution to the problem of speaker normalization.
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Affiliation(s)
- Philip J. Monahan
- Basque Center on Cognition, Brain and Language, Donostia-San Sebastián, Spain
| | - William J. Idsardi
- Department of Linguistics, University of Maryland, USA
- Neuroscience and Cognitive Science Program University of Maryland, USA
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Frye RE, Malmberg B, McLean J, Swank P, Smith K, Papanicolaou A, Landry S. Increased left prefrontal activation during an auditory language task in adolescents born preterm at high risk. Brain Res 2010; 1336:89-97. [PMID: 20381475 DOI: 10.1016/j.brainres.2010.03.093] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2009] [Revised: 03/09/2010] [Accepted: 03/26/2010] [Indexed: 11/28/2022]
Abstract
Although individuals born preterm are at risk for cognitive dysfunction, few studies have examined functional brain reorganization in these individuals. We used magnetoencephalography (MEG) to examine cortical reorganization related to preterm birth. Thirty-one adolescents systemically selected from a longitudinal study on child development based on gestational age, birth weight and medical complications (full term, low risk preterm, high-risk preterm) performed real-word and non-word auditory rhyme tasks during MEG recording. Equivalent current dipoles were localized every 4ms during the 50- to 250-ms period following the onset of the auditory stimulus. The association between the number of dipoles (NODs) and birth group, language task, latency and phonological skills was examined. Adolescents born preterm at high risk demonstrated a greater NODs in the left Broca's and prefrontal areas combined, left cingulate gyrus and left superior temporal gyrus and a fewer NODs in the right superior temporal gyrus as compared to those born preterm at low risk and term. A greater NODs in the left Broca's and prefrontal areas combined and fewer NODs in the left cingulate gyrus was associated with better phonological skills only in adolescents born preterm at high risk. These results suggest that the language networks are reorganized in adolescents born preterm at high risk. Increased prefrontal activity has also been seen in adolescents born preterm during a reading task and in young adults with a history of dyslexia who are well compensated for their disorder. We suggest that this increased prefrontal activation may represent increased top-down control of weak posterior language networks.
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Affiliation(s)
- Richard E Frye
- Division of Child and Adolescent Neurology, Department of Pediatrics, University of Texas Health Science Center, Houston, TX, USA.
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Frye RE, Malmberg B, Desouza L, Swank P, Smith K, Landry S. Increased prefrontal activation in adolescents born prematurely at high risk during a reading task. Brain Res 2009; 1303:111-9. [PMID: 19796631 DOI: 10.1016/j.brainres.2009.09.091] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2009] [Revised: 09/20/2009] [Accepted: 09/23/2009] [Indexed: 11/18/2022]
Abstract
Although individuals born prematurely have subtle white matter abnormalities and are at risk for cognitive dysfunction, few studies have examined functional reorganization in these individuals. In this study we use magnetoencephalography (MEG) to examine cortical reorganization related to prematurity. Thirty-one adolescents systemically selected from a longitudinal study on child development based on gestational age, birth weight and neonatal complications (full term, low-risk premature, high-risk premature) and reading ability (good, average or poor) performed two reading-based rhyme tasks during MEG recording. Equivalent current dipoles were localized every 4 ms during the 150 ms to 550 ms period following the onset of the word presentation. The association of the mean number of dipole (NOD) with birth risk, reading ability and latency was examined. During the real-word rhyme task, adolescents born at high-risk demonstrated a greater NOD in the left prefrontal area than those born at low-risk and term. During the non-word rhyme task, good and average readers born at high-risk demonstrated a greater NOD in the left prefrontal area than good and average readers born at low-risk and term. Time course analysis confirmed increased activation in the left prefrontal regions of those born at high-risk. This study suggests that adolescents born prematurely at high-risk, as compared to those born at low-risk and term, demonstrate increased prefrontal cortical activation during a reading task. These results suggest a reorganization of the prefrontal cortex in adolescents born prematurely at high-risk.
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Affiliation(s)
- Richard E Frye
- Division of Child and Adolescent Neurology, University of Texas Health Science Center, Houston, TX 77030, USA.
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