Mapping Cortico-Striatal Connectivity onto the Cortical Surface: A New Tractography-Based Approach to Study Huntington Disease

Centre Hospitalier Universitaire Vaudois Lausanne – CHUV, UNIL, Switzerland
PLoS ONE (Impact Factor: 3.53). 02/2013; 8(2):e53135. DOI: 10.1371/journal.pone.0053135
Source: PubMed

ABSTRACT Huntington disease (HD) is associated with early and severe damage to the basal ganglia and particularly the striatum. We investigated cortico-striatal connectivity modifications occurring in HD patients using a novel approach which focuses on the projection of the connectivity profile of the basal ganglia onto the cortex. This approach consists in computing, for each subcortical structure, surface connectivity measures representing its strength of connections to the cortex and comparing these measures across groups. In this study, we focused on Huntington disease as an application of this new approach. First, surface cortico-striatal connectivity measures of a group of healthy subjects were averaged in order to infer the "normal" connectivity profile of the striatum to the cortex. Second, a statistical analysis was performed from the surface connectivity measures of healthy subjects and HD patients in order to detect the cortical gyri presenting altered cortico-striatal connectivity in HD. Lastly, percentage differences of connectivity between healthy subjects and patients were inferred, for each nucleus of the striatum, from the connectivity measures of the cortical gyri presenting a significant connectivity difference between the two groups. These percentage differences characterize the axonal disruptions between the striatum and the cortex occurring in HD. We found selective region-specific degeneration of cortical connections predominating for associative and primary sensorimotor connections and with relative preservation of limbic connections. Our method can be used to infer novel connectivity-based markers of HD pathological process.

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Available from: Linda Marrakchi-Kacem, Aug 18, 2015
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    • "To our knowledge, reductions in subcortical–cortical structural connections have been shown in Huntington's disease subjects in comparison with healthy controls in four studies to date [Bohanna et al., 2011a,b; Kloppel et al., 2008; Marrakchi-Kacem et al., 2010; Marrakchi-Kacem et al., 2013] . Connections to associative [Marrakchi-Kacem et al., 2013] and sensorimotor [Bohanna et al., 2011a, 2011b; Marrakchi-Kacem et al., 2013] cortex appear particularly affected. Altered diffusion metrics within tractographygenerated white matter pathways have also been shown [Douaud et al., 2009; Dumas et al., 2012]. "
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