Anterior and posterior commissures in agenesis of the corpus callosum: alternative pathways for attention processes?


Developmental absence (agenesis) of the corpus callosum (AgCC) is a congenital brain malformation resulting from disruption of corpus callosum formation, a structure that is crucial for the transfer and integration of information, including attention processes, across the brain. This study aimed to investigate previously proposed candidates for alternative inter-hemispheric pathways in AgCC by examining (1) white matter volume and microstructure of the anterior and posterior commissures in children with AgCC compared to typically developing controls (TDC), and (2) in children with AgCC, examine the associations of white matter volume and microstructure of the anterior and posterior commissures and any remaining corpus callosum with attention processes. Participants were 21 children with AgCC (13 complete, 8 partial) recruited from The Royal Children's Hospital, Melbourne, and 30 TDC aged 8–17 years. T1-and diffusion-weighted MR sequences were used to calculate volume and microstructural parameters. Neuropsychological testing assessed attention processes. We found the anterior commissure was significantly larger in volume in children with AgCC than TDC (p = .027), with reduced mean FA (p = .001) associated with increased mean RD (p < .001). In children with AgCC, we found microstructural properties of the anterior commissure associated with attentional processes, specifically, mean FA of the anterior commissure was associated with better divided attention (p = .03), and the association between alerting attention and mean AD and RD was found to be moderated by age (p = .027, p = .008) and the degree of corpus callosum agenesis (p = .025, p = .016). Furthermore, in partial AgCC, larger posterior commissure volume was associated with better orienting attention (p = .035). In conclusion, we provide evidence that the volume and microstructure of the anterior commissure are altered in children with AgCC, and this neuroplastic response might have an influence on attention processes.

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Divisions: Life & Health Sciences > Psychology
Life & Health Sciences
Additional Information: © 2019, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Funding: Victorian Government’s Operational Infrastructure Support Program, and the Murdoch Children’s Research Institute and the Alain Patry Grant from the Geneva Academic Society. Swiss National Science Foundation Doc.CH scholarship. European Research Council Consolidator Fellowship [682734]. Melbourne Children’s Clinician Scientist Fellowship. Australian National Health and Medical Research Council Senior Practitioner Fellowship.
Uncontrolled Keywords: Agenesis of the corpus callosum,Alternative inter-hemispheric pathway,Anterior and posterior commissures,Attention processes,Development,Neuropsychology and Physiological Psychology,Experimental and Cognitive Psychology,Cognitive Neuroscience
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Related URLs: https://linking ... 010945219303363 (Publisher URL)
http://www.scop ... tnerID=8YFLogxK (Scopus URL)
Published Online Date: 2019-12-01
Published Date: 2019-12-01
Authors: Siffredi, Vanessa
Wood, Amanda G. ( 0000-0002-1537-6858)
Leventer, Richard
Vaessen, Maarten
Mcilroy, Alissandra
Anderson, Vicki
Vuilleumier, Patrik
Spencer-smith, Megan M.



Version: Accepted Version

Access Restriction: Restricted to Repository staff only until 23 October 2020.

License: Creative Commons Attribution Non-commercial No Derivatives

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