- Email: [email protected]
The usefulness of using electrophysiology in children to better understand the neurotoxic effects associated with exposure to environmental chemicals
IOP 2016
factors and co-morbidities. In particular, four invited speakers will discuss how endogenous (ie., genetic, brain lesions) and exogenous (ie, premature, neurotoxic agents) risk factors are associated with neurodevelopmental disorders onset and how these risk factors may contribute to shared symptomatology. doi:10.1016/j.ijpsycho.2016.07.156
456 Language function development and establishment of language brain networks in healthy infants and children and in children with neurodevelopmental conditions Anne Gallagher Psychology Department Université de Montréal, Canada Language development can be modulated by multiple environmental and clinical factors. Using near Infrared Spectroscopy (NIRS) and electrophysiology (EEG), which are non invasive neuroimaging techniques that are highly suitable for pediatric populations, we investigated typical and altered language acquisition in infants. First studying the receptive language development, we found in healthy babies distinct hemispheric cerebral representations associated with maternal and foreign language processing already established on the first day of life. In a series of subsequent studies, we investigated language development and establishment of language brain networks in infants born prematurely and in 4-month-old babies with congenital heart disease. Results suggested that these babies are more likely to be affected by language processing alterations than their fullterm contemporaries or than healthy children. Ultimately, these studies could lead to the identification of early cerebral markers for delayed language development, which could facilitate early interventions in various clinical populations. Finally, we used NIRS-EEG for the characterization of epileptic seizures, for epileptogenic zone localization as well as for presurgical language mapping. In addition to other conventional and neuroimaging tools, NIRS-EEG has been found to be a critical source of information in the presurgical management of some children with epilepsy. Although further research and developments are still needed for NIRS-EEG to be included in the standard clinical care, multiple applications have now been developed and are used in some pediatric epilepsy clinics. doi:10.1016/j.ijpsycho.2016.07.157
420 Learning mechanisms in intellectual disability Sarah Lippé University of Montreal, CHU Sainte-Justine, Canada Background: Repetition suppression (RS) and repetition enhancement (RE) are brain responses to a repeated stimulus (Sawamura, Orban, & Vogels, 2006). RS has been related to familiar stimulus recognition whereas RE has been related to repetition of unfamiliar stimuli (Henson, 2016). They are considered to be among the most primitive or elementary forms of perceptual learning, which occur as early as the foetal stage (Leader, Baillie, Martin, & Vermeulen, 1982). Fragile X Syndrome (FXS) is a neurodevelopmental genetic disorder causing cognitive and behavioural deficits. FXS is caused by a trinucleotide repeat expansion of more than 200 repetitions in the 5’ UTR of the FMR1 (‘Fragile X Mental Retardation 1’) gene, which
47
is located on the X-chromosome (Penagarikano, Mulle, & Warren, 2007). This mutation prevents expression of the Fragile X Mental Retardation Protein (FMRP), which is known to repress the translation of specific mRNAs in response to the activation of metabotropic Glutamate Receptors (mGluRs) (Bear, Huber, & Warren, 2004). The emerging view is that defects in synaptic plasticity and morphogenesis of dendritic spines are common features at the root of many neurodevelopmental disorders, including FXS. Objectives: Here we discuss how repetition effects can predict intellectual disability severity. Methods: Visual and auditory repetition effects have been studied in a Fragile X Syndrome population, using high density EEG. Energy and time-frequency analyses were used. Machine learning algorithms (support vector machine) have been used to verify the strength of the group prediction accuracy levels. Results: Results show significant reduction in repetition suppression effects in FXS patients in both the visual and the auditory modality. Results were shown by absence of repetition effects in energy or low frequency bands synchronisation in FXS patients. However, support vector machine algorithm could predict with 85% accuracy IQ levels (50NIQb50) of FXS based on 1-10 repetitions energy values. Conclusion: Repetition effects potentially reflect a core deficit in FXS patients, which could be a marker of cognitive functions. Further studies are needed to verify whether these findings can be generalized to other intellectual disability syndromes.
doi:10.1016/j.ijpsycho.2016.07.158
470 The usefulness of using electrophysiology in children to better understand the neurotoxic effects associated with exposure to environmental chemicals Dave Saint-Amour Université du Québec à Montréal, Calibri The Inuit from Northern Quebec (Nunavik, Canada) are highly exposed to environmental contaminants (EC) due to their marine diet and the bioaccumulation of EC in the fish they consume. Prenatal and postnatal exposures to these chemicals have been associated with impairments of neurobehavioral functions (e.g., vision, IQ, attention, memory). To better investigate the nature of EC exposure on human brain development, we investigated the neurophysiological correlates of some of these deficits using visual evoked potentials (VEP) for sensory evaluation, and event related potentials (ERP) for cognitive evaluation, in 11 year-old Inuit children. Blood concentrations of several chemicals were measured at birth from umbilical cord blood samples, and again at the time of testing, to estimate prenatal and postnatal exposures respectively. The relationships between EC (methylmercury, lead, and polychlorinated biphenyls, PCBs), and outcomes (brain responses) were assessed by multivariate regression analyses, taking into account several confounding factors including socio-demographic characteristics and nutrients contained in the fish. Results from three electrophysiological studies are presented: 1) VEP (n = 150), auditory oddball (n = 118) and response inhibition under a Continuous Performance Task (n = 196). Overall, data showed that prenatal methylmercury exposure alters early processing of sensory information, while exposure to lead and PCBs (pre- and postnatal) appears to affect information processing at later stages, when the information is being consciously evaluated. These effects were mainly observed on amplitude measurements.
48
IOP 2016
An interaction between methylmercury and selenium exposures was revealed in such a way that selenium partially mitigated deleterious effects of methylmercury on VEP. By contrast to behavioural assessments, our electrophysiological findings suggest that recording of electrical brain activity is a powerful tool to dissect the effects of specific chemicals on brain function. Furthermore, this approach is particularly relevant in relation to children since evoked potential protocols requiring minimal verbal or motor responses can be used. doi:10.1016/j.ijpsycho.2016.07.159
536 The establishment of multimodal biomarkers to define and predict the neurodevelopmental outcome of very premature infants, a population of high risk of cognitive impairments Fabrice Wallois, Mahdi Mahmoudzadeh University of Picardie, Amiens, France Brain development is based on the consistent implementation of neural networks at the fetal stage. All interactions with the mechanisms of (1) neuronal proliferation and migration, (2) selection and synaptic reorganization and (3) myelination may cause neurodevelopmental pathologies such as cognitive disorders and epilepsy. The development of neural networks is based on structural and functional genetic endowments that combine anatomical asymmetries specific genes localization, endogenous generators, innate and acquired capacity of the networks to encode for vital information. HR EEG and HR NIRS used in premature newborns as early as 26-32s allow to better characterizing the establishment of these networks, including language and communication networks. We show that even before the cortical structures receive auditory sensory information’s, the immature network is the loci of endogenous non-sensory driven activities that prepares neural networks to encode this information. From 28sAG on, when thalamic afferents connect the cortical plate, the immature brain is capable of encoding phonetic and voice information’s without prior learning. Moreover, in situations of intraventricular hemorrhage, the coding speed and the magnitude of electrical responses to sensory stimulation are diminished and neurovascular coupling is absent. This last is a good indicator of the development of the fine interactions between neural and vascular anatomical systems that constitute a unique functional system. The availability of such neurobiomraquers to study the brain plasticity at such an early stage of development opens new perspectives on the prevention of cognitive risks of prematurity and of perinatal anoxo-hypoxia.
doi:10.1016/j.ijpsycho.2016.07.160
59 Symposium A6 Behavioural and electrophysiological outcomes in neurological restoration Organizer: María L. Bringas (Cuba), Anai Guerra-Labrada (Cuba), Elizabeth Fernández-Martínez (Cuba), Xia Jang (China)
How to evaluate objectively the neurological restoration becomes today a very important question. Results obtained using different methodologies (i.e., scales and behavioural questionnaires, EEG, ERP data) and intervention techniques (motor and sensory stimulation, cognitive computerized software, music therapy and neurofeedback) will be reviewed in populations of patients with risk or neurological damage. A. Guerra will present different results of an intensive neurodevelopmental intervention based in global gymnastic and multiple sensorial stimulation in two groups of children with Very Low Birth Weight (MBP) and hypoxic ischemic (EHI). E. Fernandez will examine how the training of specific cognitive abilities using computerized software contributes to recovery of cognitive funtions in a sample of patient with acquired brain damage. A. Castillo will present EEG changes after Neurofeedback training in a sample of brain traumatic injury patients. ML Bringas will show differential changes at the ERPs related with music therapy in children with neurological disorders. The last speaker X. Yang will report how Mozart music may help to promote the recovery of cognitive damage due to seizure activities in rats, providing a novel intervention strategy to diminish cognitive deficits in TLE patients. Finally, ML Bringas will summarised the different methods of treatment and assessment, comparing and discussing the advantages and disvantages of each one, in adults and children, and the limitations of the pre-clinical models to translation to clinical settings. doi:10.1016/j.ijpsycho.2016.07.161
19 Effectiveness of Music Therapy in Children with Neurological Disorders María L. Bringas Joint China Cuba Lab for Translational Research in Neurotechnology Key Lab for Neuroinformation UESTC, Chengdu, China Cuban Neurosciences Center, Havana, Cuba Introduction: The rehabilitation of children with severe neurological disorders is an area of great current interest (Katona, 1989). Different therapies have been designed to enhance neural plasticity and thus promote recovery of function. Objective: To test real world effectiveness of a music therapy (MT) intervention for children with severe neurological disorders. Material and methods: This study was a two-armed parallel group design aimed where the control group received only the standard neurorestoration program and the experimental group received an additional MT “Auditory Attention plus Communication (ACC) protocol” just before the usual occupational and speech therapy. Results: Multivariate Item Response Theory (MIRT) identified a neuropsychological status-latent variable manifested in all children and which exhibited highly significant changes only in the experimental group. Changes in brain plasticity also occurred in the experimental group, as evidenced using a Mismatch Event Related paradigm which revealed significant post intervention positive responses in the latency range between 308 and 400 ms in frontal regions. LORETA EEG source analysis identified prefrontal and midcingulate regions as differentially activated by the MT in the experimental group. Conclusions: We confirmed the effectiveness MT in addition to standard neurorestoration therapy as reflected in non-music performance outcome measures. The therapeutic effects of MT were demonstrated by improved attention and communication across
factors and co-morbidities. In particular, four invited speakers will discuss how endogenous (ie., genetic, brain lesions) and exogenous (ie, premature, neurotoxic agents) risk factors are associated with neurodevelopmental disorders onset and how these risk factors may contribute to shared symptomatology. doi:10.1016/j.ijpsycho.2016.07.156
456 Language function development and establishment of language brain networks in healthy infants and children and in children with neurodevelopmental conditions Anne Gallagher Psychology Department Université de Montréal, Canada Language development can be modulated by multiple environmental and clinical factors. Using near Infrared Spectroscopy (NIRS) and electrophysiology (EEG), which are non invasive neuroimaging techniques that are highly suitable for pediatric populations, we investigated typical and altered language acquisition in infants. First studying the receptive language development, we found in healthy babies distinct hemispheric cerebral representations associated with maternal and foreign language processing already established on the first day of life. In a series of subsequent studies, we investigated language development and establishment of language brain networks in infants born prematurely and in 4-month-old babies with congenital heart disease. Results suggested that these babies are more likely to be affected by language processing alterations than their fullterm contemporaries or than healthy children. Ultimately, these studies could lead to the identification of early cerebral markers for delayed language development, which could facilitate early interventions in various clinical populations. Finally, we used NIRS-EEG for the characterization of epileptic seizures, for epileptogenic zone localization as well as for presurgical language mapping. In addition to other conventional and neuroimaging tools, NIRS-EEG has been found to be a critical source of information in the presurgical management of some children with epilepsy. Although further research and developments are still needed for NIRS-EEG to be included in the standard clinical care, multiple applications have now been developed and are used in some pediatric epilepsy clinics. doi:10.1016/j.ijpsycho.2016.07.157
420 Learning mechanisms in intellectual disability Sarah Lippé University of Montreal, CHU Sainte-Justine, Canada Background: Repetition suppression (RS) and repetition enhancement (RE) are brain responses to a repeated stimulus (Sawamura, Orban, & Vogels, 2006). RS has been related to familiar stimulus recognition whereas RE has been related to repetition of unfamiliar stimuli (Henson, 2016). They are considered to be among the most primitive or elementary forms of perceptual learning, which occur as early as the foetal stage (Leader, Baillie, Martin, & Vermeulen, 1982). Fragile X Syndrome (FXS) is a neurodevelopmental genetic disorder causing cognitive and behavioural deficits. FXS is caused by a trinucleotide repeat expansion of more than 200 repetitions in the 5’ UTR of the FMR1 (‘Fragile X Mental Retardation 1’) gene, which
47
is located on the X-chromosome (Penagarikano, Mulle, & Warren, 2007). This mutation prevents expression of the Fragile X Mental Retardation Protein (FMRP), which is known to repress the translation of specific mRNAs in response to the activation of metabotropic Glutamate Receptors (mGluRs) (Bear, Huber, & Warren, 2004). The emerging view is that defects in synaptic plasticity and morphogenesis of dendritic spines are common features at the root of many neurodevelopmental disorders, including FXS. Objectives: Here we discuss how repetition effects can predict intellectual disability severity. Methods: Visual and auditory repetition effects have been studied in a Fragile X Syndrome population, using high density EEG. Energy and time-frequency analyses were used. Machine learning algorithms (support vector machine) have been used to verify the strength of the group prediction accuracy levels. Results: Results show significant reduction in repetition suppression effects in FXS patients in both the visual and the auditory modality. Results were shown by absence of repetition effects in energy or low frequency bands synchronisation in FXS patients. However, support vector machine algorithm could predict with 85% accuracy IQ levels (50NIQb50) of FXS based on 1-10 repetitions energy values. Conclusion: Repetition effects potentially reflect a core deficit in FXS patients, which could be a marker of cognitive functions. Further studies are needed to verify whether these findings can be generalized to other intellectual disability syndromes.
doi:10.1016/j.ijpsycho.2016.07.158
470 The usefulness of using electrophysiology in children to better understand the neurotoxic effects associated with exposure to environmental chemicals Dave Saint-Amour Université du Québec à Montréal, Calibri The Inuit from Northern Quebec (Nunavik, Canada) are highly exposed to environmental contaminants (EC) due to their marine diet and the bioaccumulation of EC in the fish they consume. Prenatal and postnatal exposures to these chemicals have been associated with impairments of neurobehavioral functions (e.g., vision, IQ, attention, memory). To better investigate the nature of EC exposure on human brain development, we investigated the neurophysiological correlates of some of these deficits using visual evoked potentials (VEP) for sensory evaluation, and event related potentials (ERP) for cognitive evaluation, in 11 year-old Inuit children. Blood concentrations of several chemicals were measured at birth from umbilical cord blood samples, and again at the time of testing, to estimate prenatal and postnatal exposures respectively. The relationships between EC (methylmercury, lead, and polychlorinated biphenyls, PCBs), and outcomes (brain responses) were assessed by multivariate regression analyses, taking into account several confounding factors including socio-demographic characteristics and nutrients contained in the fish. Results from three electrophysiological studies are presented: 1) VEP (n = 150), auditory oddball (n = 118) and response inhibition under a Continuous Performance Task (n = 196). Overall, data showed that prenatal methylmercury exposure alters early processing of sensory information, while exposure to lead and PCBs (pre- and postnatal) appears to affect information processing at later stages, when the information is being consciously evaluated. These effects were mainly observed on amplitude measurements.
48
IOP 2016
An interaction between methylmercury and selenium exposures was revealed in such a way that selenium partially mitigated deleterious effects of methylmercury on VEP. By contrast to behavioural assessments, our electrophysiological findings suggest that recording of electrical brain activity is a powerful tool to dissect the effects of specific chemicals on brain function. Furthermore, this approach is particularly relevant in relation to children since evoked potential protocols requiring minimal verbal or motor responses can be used. doi:10.1016/j.ijpsycho.2016.07.159
536 The establishment of multimodal biomarkers to define and predict the neurodevelopmental outcome of very premature infants, a population of high risk of cognitive impairments Fabrice Wallois, Mahdi Mahmoudzadeh University of Picardie, Amiens, France Brain development is based on the consistent implementation of neural networks at the fetal stage. All interactions with the mechanisms of (1) neuronal proliferation and migration, (2) selection and synaptic reorganization and (3) myelination may cause neurodevelopmental pathologies such as cognitive disorders and epilepsy. The development of neural networks is based on structural and functional genetic endowments that combine anatomical asymmetries specific genes localization, endogenous generators, innate and acquired capacity of the networks to encode for vital information. HR EEG and HR NIRS used in premature newborns as early as 26-32s allow to better characterizing the establishment of these networks, including language and communication networks. We show that even before the cortical structures receive auditory sensory information’s, the immature network is the loci of endogenous non-sensory driven activities that prepares neural networks to encode this information. From 28sAG on, when thalamic afferents connect the cortical plate, the immature brain is capable of encoding phonetic and voice information’s without prior learning. Moreover, in situations of intraventricular hemorrhage, the coding speed and the magnitude of electrical responses to sensory stimulation are diminished and neurovascular coupling is absent. This last is a good indicator of the development of the fine interactions between neural and vascular anatomical systems that constitute a unique functional system. The availability of such neurobiomraquers to study the brain plasticity at such an early stage of development opens new perspectives on the prevention of cognitive risks of prematurity and of perinatal anoxo-hypoxia.
doi:10.1016/j.ijpsycho.2016.07.160
59 Symposium A6 Behavioural and electrophysiological outcomes in neurological restoration Organizer: María L. Bringas (Cuba), Anai Guerra-Labrada (Cuba), Elizabeth Fernández-Martínez (Cuba), Xia Jang (China)
How to evaluate objectively the neurological restoration becomes today a very important question. Results obtained using different methodologies (i.e., scales and behavioural questionnaires, EEG, ERP data) and intervention techniques (motor and sensory stimulation, cognitive computerized software, music therapy and neurofeedback) will be reviewed in populations of patients with risk or neurological damage. A. Guerra will present different results of an intensive neurodevelopmental intervention based in global gymnastic and multiple sensorial stimulation in two groups of children with Very Low Birth Weight (MBP) and hypoxic ischemic (EHI). E. Fernandez will examine how the training of specific cognitive abilities using computerized software contributes to recovery of cognitive funtions in a sample of patient with acquired brain damage. A. Castillo will present EEG changes after Neurofeedback training in a sample of brain traumatic injury patients. ML Bringas will show differential changes at the ERPs related with music therapy in children with neurological disorders. The last speaker X. Yang will report how Mozart music may help to promote the recovery of cognitive damage due to seizure activities in rats, providing a novel intervention strategy to diminish cognitive deficits in TLE patients. Finally, ML Bringas will summarised the different methods of treatment and assessment, comparing and discussing the advantages and disvantages of each one, in adults and children, and the limitations of the pre-clinical models to translation to clinical settings. doi:10.1016/j.ijpsycho.2016.07.161
19 Effectiveness of Music Therapy in Children with Neurological Disorders María L. Bringas Joint China Cuba Lab for Translational Research in Neurotechnology Key Lab for Neuroinformation UESTC, Chengdu, China Cuban Neurosciences Center, Havana, Cuba Introduction: The rehabilitation of children with severe neurological disorders is an area of great current interest (Katona, 1989). Different therapies have been designed to enhance neural plasticity and thus promote recovery of function. Objective: To test real world effectiveness of a music therapy (MT) intervention for children with severe neurological disorders. Material and methods: This study was a two-armed parallel group design aimed where the control group received only the standard neurorestoration program and the experimental group received an additional MT “Auditory Attention plus Communication (ACC) protocol” just before the usual occupational and speech therapy. Results: Multivariate Item Response Theory (MIRT) identified a neuropsychological status-latent variable manifested in all children and which exhibited highly significant changes only in the experimental group. Changes in brain plasticity also occurred in the experimental group, as evidenced using a Mismatch Event Related paradigm which revealed significant post intervention positive responses in the latency range between 308 and 400 ms in frontal regions. LORETA EEG source analysis identified prefrontal and midcingulate regions as differentially activated by the MT in the experimental group. Conclusions: We confirmed the effectiveness MT in addition to standard neurorestoration therapy as reflected in non-music performance outcome measures. The therapeutic effects of MT were demonstrated by improved attention and communication across