Organization of language networks in children: Functional magnetic resonance imaging studies

Sachs, Bonnie C.; Gaillard, William D.

doi:10.1007/s11910-003-0068-z

Cited by 25 publications

(14 citation statements)

References 36 publications

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“…In this series, seven of the eight children showed clear left dominance. These children had little reorganization despite early left perisylvian epilepsy, as it was found in other studies (Duchowny et al, 1996; Liegeois et al, 2004), unlike some reported cases, which showed more reorganization with early seizure onset (Gaillard et al, 2000; Sachs & Gaillard, 2003; Wood et al, 2004; Wilke et al, 2006).…”

Section: Discussionsupporting

confidence: 52%

Presurgical language mapping in children with epilepsy: Clinical usefulness of functional magnetic resonance imaging for the planning of cortical stimulation

et al. 2011

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SUMMARYPurpose: Presurgical language mapping in dominant hemisphere epilepsy to evaluate the risk of postoperative deficit is particularly difficult in children. Extraoperative invasive cortical stimulation can show some areas critical to language, but not all of them, due to scarce sampling, poor cooperation, cortical immaturity, or network reorganization, whereas functional magnetic resonance imaging (fMRI) displays entire networks involved in, but not necessarily critical to, language. In a homogeneous series of children with epilepsy, we compared the contributions of language fMRI and depth electrode stimulations to optimize language mapping. Methods: Eight children (7.5-15.5 years) with left frontal or temporal epilepsy underwent language fMRI and language stimulation with depth electrodes as part of their comprehensive presurgical workup. fMRI data collected during sentence generation were analyzed using statistical parametric mapping (SPM2) (false discovery rate [FDR] p < 0.05). Bipolar stimulations were performed during language production tasks. By coregistering fMRI and postimplantation computed tomography (CT) images, we were able to directly compare the cortical areas identified by both investigations.Key Findings: fMRI during sentence generation robustly showed activation in the whole perisylvian regions with little reorganization (left hemisphere dominant in 7). Of the 184 electrode contacts tested for language, only 8 were positive (language disruption) in three of the seven patients with periictal language impairment and left language dominance. All of the positive contacts colocalized with an fMRI activated cluster, that is, fMRI did not miss any region critical to language (sensitivity = 100%). However, 54 of the 176 negative contacts were within activated clusters (low specificity). Significance: In children with epilepsy, the sensitivity of fMRI during sentence generation allows for the detection of all critical regions displayed by cortical stimulation within the large perisylvian language network, but with a low specificity. It is, therefore, useful to optimize the placement of intracranial electrodes when language mapping is necessary. Systematic planning of the electrode placement according to language fMRI maps should increase the yield of extraoperative cortical stimulation, which appears rather low in children when compared to adults.

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Section: Discussionsupporting

confidence: 52%

Presurgical language mapping in children with epilepsy: Clinical usefulness of functional magnetic resonance imaging for the planning of cortical stimulation

et al. 2011

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“…In line with studies showing the utility of presurgical fMRI language mapping in adults (Binder et al, 1996;Gaillard et al, 2002;Roux et al, 2003;Rutten et al, 2002;Tie et al, 2008Tie et al, , 2009, studies have reported the potential utility of this procedure in the even more crucial context of childhood (Anderson et al, 2006;Gaillard et al, 2000Gaillard et al, , 2001bHertz-Pannier et al, 1997;Holland et al, 2001;Wilke et al, 2005Wilke et al, , 2006. For research purposes, fMRI allows to specify the normal functional development of the brain (Durston and Casey, 2006) and, particularly, the functional development of language during childhood (Holland et al, 2007;Sachs and Gaillard, 2003;Gaillard et al, 2006). One promising perspective is the investigation of the neural bases of developmental disorders, whose aetiology remains largely unknown Frith, 2006;O'Shaughnessy et al, 2008;Wilke et al, 2003a), including childhood developmental language disorders, (Dick et al, 2008;Friederici, 2006;Rapin et al, 2003).…”

Section: Introductionmentioning

confidence: 83%

FMRI language mapping in children: A panel of language tasks using visual and auditory stimulation without reading or metalinguistic requirements

et al. 2010

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In the context of presurgical mapping or investigation of neurological and developmental disorders in children, language fMRI raises the issue of the design of a tasks panel achievable by young disordered children. Most language tasks shown to be efficient with healthy children require metalinguistic or reading abilities, therefore adding attentional, cognitive and academic constraints that may be problematic in this context. This study experimented a panel of four language tasks that did not require high attentional skills, reading, or metalinguistic abilities. Two reference tasks involving auditory stimulation (words generation from category, "category"; auditory responsive naming, "definition") were compared with two new tasks involving visual stimulation. These later were designed to tap spontaneous phonological production, in which the names of pictures to be named involve a phonological difference (e.g. in French poule/boule/moule; "phon-diff") or change of segmentation (e.g. in French car/car-te/car-t-on; "phon-seg"). Eighteen healthy children participated (mean age: 12.7+/-3 years). Data processing involved normalizing the data via a matched pairs pediatric template, and inter-task and region of interest analyses with laterality assessment. The reference tasks predominantly activated the left frontal and temporal core language regions, respectively. The new tasks activated these two regions simultaneously, more strongly for the phon-seg task. The union and intersection of all tasks provided more sensitive or specific maps. The study demonstrates that both reference and new tasks highlight core language regions in children, and that the latter are useful for the mapping of spontaneous phonological processing. The use of several different tasks may improve the sensitivity and specificity of fMRI.

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“…Language acquisition, for instance, appears to rely on prosodic cues to a much greater extent than does adult language processing (Gerken, 1996; Hirsh‐Pasek, Kemler Nelson, Jusczyk, Cassidy, Druss & Kennedy, 1987), and so on the interactions between the hemispheres. Studies of language processing show more bi‐lateral activation in infants than in adults (Dehaene‐Lambertz, 2000; Dehaene‐Lambertz & Dehaene, 1994; Dehaene‐Lambertz, Dehaene & Hertz‐Pannier, 2002; Sachs & Gaillard, 2003). Moreover, disruptions in the networks responsible for processing any of the linguistic, and supra‐linguistic, input – e.g.…”

Section: Discussionmentioning

confidence: 99%

Growth‐related neural reorganization and the autism phenotype: a test of the hypothesis that altered brain growth leads to altered connectivity

Lewis

Elman

2007

Developmental Science

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Theoretical considerations, and findings from computational modeling, comparative neuroanatomy and developmental neuroscience, motivate the hypothesis that a deviant brain growth trajectory will lead to deviant patterns of change in cortico-cortical connectivity. Differences in brain size during development will alter the relative cost and effectiveness of short-and long-distance connections, and should thus impact the growth and retention of connections. Reduced brain size should favor long-distance connectivity; brain overgrowth should favor short-distance connectivity; and inconsistent deviations from the normal growth trajectory -as occurs in autism -should result in potentially disruptive changes to established patterns of functional and physical connectivity during development. To explore this hypothesis, neural networks which modeled inter-hemispheric interaction were grown at the rate of either typically developing children or children with autism. The influence of the length of the inter-hemispheric connections was analyzed at multiple developmental time-points. The networks that modeled autistic growth were less affected by removal of the inter-hemispheric connections than those that modeled normal growth -indicating a reduced reliance on long-distance connections -for short response times, and this difference increased substantially at approximately 24 simulated months of age. The performance of the networks showed a corresponding decline during development. And direct analysis of the connection weights showed a parallel reduction in connectivity. These modeling results support the hypothesis that the deviant growth trajectory in autism spectrum disorders may lead to a disruption of established patterns of functional connectivity during development, with potentially negative behavioral consequences, and a subsequent reduction in physical connectivity. The results are discussed in relation to the growing body of evidence of reduced functional and structural connectivity in autism, and in relation to the behavioral phenotype, particularly the developmental aspects.

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Organization of language networks in children: Functional magnetic resonance imaging studies

Cited by 25 publications

References 36 publications

Presurgical language mapping in children with epilepsy: Clinical usefulness of functional magnetic resonance imaging for the planning of cortical stimulation

Presurgical language mapping in children with epilepsy: Clinical usefulness of functional magnetic resonance imaging for the planning of cortical stimulation

FMRI language mapping in children: A panel of language tasks using visual and auditory stimulation without reading or metalinguistic requirements

Growth‐related neural reorganization and the autism phenotype: a test of the hypothesis that altered brain growth leads to altered connectivity

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