Comparative analysis of regional gray and white matter atrophy between limb- and bulbar-onset ALS patients.

<p>(A, B) The limb-onset subtype was characterized by decreased gray matter volume around motor areas (pre- and post-central and medial superior frontal areas) relative to the bulbar-onset subtype. (C, D) The bulbar-onset subtype exhibited atrophy in both gray and white matter in extra-motor areas—i.e., bilateral frontal, temporal, and cerebellar areas as compared to the limb type (displayed at P < 0.001, uncorrected, extended threshold = 100 voxels). The colored bar represents the T score.