Influence of age, lesion volume, and damage to dorsal versus ventral streams to viewer- and stimulus-centered hemispatial neglect in acute right hemisphere stroke.

We studied 156 individuals with acute, right hemisphere ischemic stroke on a battery of hemispatial neglect tests to distinguish between viewer-centered and stimulus-centered neglect and MRI diffusion weighted imaging. We identified the relative contributions of age, total lesion volume, and damage to subcortical and cortical grey matter regions as well as white matter tracts to both the severity and presence of significant viewer-centered and stimulus-centered neglect, using multivariable regression tests. We found that age, volume of lesion, and percent damage to the regions of interest were each independently associated with the severity of viewer-centered neglect (r2 = .31; p < .0001). However, only age (t = 3.20; p = .002) and percent damage to the angular gyrus (t = 2.63, p = .010), a dorsal stream area, predicted severity of viewer-centered neglect independently of the other variables. The same variables predicted the presence of significant viewer-centered neglect. In contrast, these variables did not significantly predict the severity of stimulus-centered neglect. However, we found that percent damage to ventral stream regions of interest (middle temporal gyrus, inferior temporal gyrus, fusiform gyrus, inferior frontal occipital gyrus, sagittal stratum, along with total infarct volume were associated with the presence of significant stimulus-centered neglect (pseudo r2 = .70, p < .0004). Only percent damage to right inferior temporal gyrus predicted stimulus-centered neglect independently of the other variables (p = .018).