In GRN carriers, we observed greater microstructural alterations on the left side and a stronger association of left cortical microstructural alterations with longitudinal cognitive decline; these observations provide first data using cortical microstructure, consistent with previous reports of greater proportion of GRN carriers with left-dominant over right-dominant neurodegenerative changes, where left-dominant GRN carriers also have a faster rate of disease progression [34]. This evidence concerns the gene GRN and Mental deterioration.