Table 4.

Comparisons of topological properties in structural brain networks of Alzheimer's disease versus multiple sclerosis

Study	Small-world network efficiency	Regional nodal efficiency
Alzheimer's disease (He et al., 2008)	An increase in local network efficiency but a decrease in global efficiency as compared to controls, suggesting a more regular configuration.	A decrease in regional efficiency of temporal and parietal association cortex areas with an increase for more primary occipital areas as compared to controls.
Multiple sclerosis (the current study)	A decrease in local network efficiency but a non-significant change in global efficiency with increasing white matter lesion load, suggesting a more random configuration.	A decrease in regional efficiency of insula and precentral gyrus as well as prefrontal and temporal association cortex areas, and an increase in the parahippocampal gyrus and angular gyrus with increasing white matter lesion load.

Note that, in the previous Alzheimer's disease study, we characterized the small-world properties and regional nodal characteristics of the structural brain networks by using clustering coefficient/shortest path length, and nodal betweenness centrality, respectively (He et al., 2008). For comparative purpose, here the Alzheimer's disease results are described from an efficiency perspective.