title: Electrophysiological Correlates of Morphological Neuroplasticity in Human Callosal Dysgenesis.
abstract: In search for the functional counterpart of the alternative Probst and sigmoid bundles, considered as morphological evidence of neuroplasticity in callosal dysgenesis, electroencephalographic (EEG) coherence analysis was combined with high resolution and diffusion tensor magnetic resonance imaging. Data of two patients with callosal agenesis, plus two with typical partial dysgenesis with a remnant genu, and one atypical patient with a substantially reduced genu were compared to those of fifteen neurotypic controls. The interhemispheric EEG coherence between homologous nontemporal brain regions corresponded to absence or partial presence of callosal connections. A generalized coherence reduction was observed in complete acallosal patients, as well as coherence preservation in the anterior areas of the two patients with a remnant genu. jThe sigmoid bundles found in three patients with partial dysgenesis correlated with augmented EEG coherence between anterior regions of one hemisphere and posterior regions of the other. These heterologous (crossed) interhemispheric connections were asymmetric in both imaging and EEG patterns, with predominance of the right-anterior-to-left-posterior connections over the mirror ones. The Probst bundles correlated with higher intrahemispheric long-distance coherence in all patients. The significant correlations observed for the delta, theta and alpha bands indicate that these alternative pathways are functional, although the neuropsychological nature of this function is still unknown.
authors.affiliation: National Institute of Women, Children and Adolescents Health Fernandes Figueira, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Lazarev
authors.affiliation: National Institute of Women, Children and Adolescents Health Fernandes Figueira, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.|Institute for Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.|D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil.
authors.forename: Myriam
authors.initials: M
authors.lastname: de Carvalho Monteiro
authors.affiliation: Institute for Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.|D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Vianna-Barbosa
authors.affiliation: National Institute of Women, Children and Adolescents Health Fernandes Figueira, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
authors.forename: Leonardo C
authors.initials: LC
authors.lastname: deAzevedo
authors.affiliation: Institute for Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Roberto
authors.initials: R
authors.lastname: Lent
authors.affiliation: Institute for Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.|D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Tovar-Moll
mesh_terms: D000293:Adolescent; D000328:Adult; D061085:Agenesis of Corpus Callosum / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D058256:Brain Waves; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D008297:Male; D009473:Neuronal Plasticity; D011859:Radiography