13 Action naming impairment in Corticobasal Syndrome

Abstract

Background Action naming is the capacity to correctly identify and name an action. Although action naming has been found to be impaired in a host of neurodegenerative conditions, its neural substrates have been rarely explored. Methods Twenty-six subjects affected with Corticobasal Syndrome (CBS) were included in the study. Action naming was assessed with Druks and Masterson Action Naming Battery; moreover all subjects underwent an extensive neuropsychological evaluation and a structural 3D MRI brain scan. Action naming data were then correlated with local gray matter densities using a voxel-wise approach. Results CBS patients showed action naming impairments compared to age-matched healthy subjects. Moreover, a linear stepwise regression analysis showed a significant association between action naming and object naming as well as non-dominant hand Finger Tapping performance. These predictors were then included in our voxel-wise correlation between gray matter densities and action naming error rates as confounding variables. Voxel-wise analysis local maxima were localized in the bilateral inferior parietal lobule, in the right insula, in the right lateral globus pallidus, in the left middle temporal gyrus, and in the left cuneus. Discussion Our data highlight the relationship between motor and non-motor deficits in movement disorders suggesting a specific role of right hemisphere and in particular of the inferior parietal lobule in verbal labeling of actions in neurodegenerative conditions.