Topological Data Analysis reveals robust alterations in the whole-brain and frontal lobe functional connectomes in Attention-Deficit/Hyperactivity Disorder

Abstract

The functional organization of the brain network (connectome) has been widely studied as a graph; however, methodological issues may affect the results, such as the brain parcellation scheme or the selection of a proper threshold value. Instead of exploring the brain in terms of a static connectivity threshold, this work explores its algebraic topology as a function of the filtration value (i.e., the connectivity threshold), a process termed the Rips filtration in Topological Data Analysis. Specifically, we characterized the transition from all nodes being isolated to being connected into a single component as a function of the filtration value, in a public dataset of children with attention-deficit/hyperactivity disorder (ADHD) and typically developing children. Results were highly congruent when using four different brain segmentations (atlases), and exhibited significant differences for the brain topology of children with ADHD, both at the whole brain network and at the functional sub-network levels, particularly involving the frontal lobe and the default mode network. Therefore, this approach may contribute to identify the neurophysio-pathology of ADHD, reducing the bias of connectomics-related methods.\n\nHighlightsO_LITopological Data Analysis was implemented in functional connectomes.\nC_LIO_LIBetti curves were assessed based on the area under the curve, slope and kurtosis.\nC_LIO_LIThe explored variables were robust along four different brain atlases.\nC_LIO_LIADHD showed lower areas, suggesting decreased functional segregation.\nC_LIO_LIFrontal and default mode networks showed the greatest differences between groups.\nC_LI\n\nGraphical Abstract\n\nO_FIG O_LINKSMALLFIG WIDTH=168 HEIGHT=200 SRC=\"FIGDIR/small/751008v1_ufig1.gif\" ALT=\"Figure 1\">\nView larger version (51K):\norg.highwire.dtl.DTLVardef@50e91corg.highwire.dtl.DTLVardef@1f837aforg.highwire.dtl.DTLVardef@10fe920org.highwire.dtl.DTLVardef@1923ead_HPS_FORMAT_FIGEXP M_FIG C_FIG