Impairment of verb processing in frontal variant-frontotemporal dementia: a dysexecutive symptom.

Object and action naming and comprehension were tested in frontotemporal dementia (frontal variant, FTD), in Alzheimer's disease (AD) and in controls. Although lower scores were obtained by all groups, we can confirm that actions were proportionally more impaired in FTD. The correlation between action naming deficit and severity of dementia was stronger in this group than in AD. The correlation analysis also suggested that the naming disorder was different in nature in FTD (mostly a dysexecutive deficit) and in AD (mostly a linguistic disorder). Our explanation is that since verbs are supposed to be more demanding of executive resources than nouns, a higher sensitivity to verbs should be expected in any brain pathology, but mostly in FTD in which executive resources are typically reduced.