The Genesis of Graphic Perseverations in Alzheimers Disease and Vascular Dementia

Objective: Perseveration is the involuntary production of iterative responses. This study explored graphic perseverative errors in Alzheimers disease and vascular dementia, to comprehend the neuropsychological correlates of this behavior. Method: We performed a retrospective analysis of graphic productions in 114 individuals with clinical diagnosis of Alzheimers disease and in 63 individuals with clinical diagnosis of vascular dementia, who completed frontal-executive, visuo-spatial, visuo-constructional, and verbal memory tests. For assessing perseverative behavior, we considered recurrent perseverations (inappropriate re-drawing of a figure drawn in a previous trial) and continuous perseverations (inappropriate replication of the same figure or of its element within one trial) produced in a standard copying task. Results: Two or more graphic perseverative errors occurred in 66/114 individuals with Alzheimers disease (57.9%) and in 31/63 individuals with vascular dementia (49.2%). Participants with moderate-to-severe dementia produced a significantly higher number of perseverations than individuals with mild dementia. Logistic regression revealed a significant relationship of graphic perseverations with frontal and visuo-constructive impairments, in both Alzheimers disease and vascular dementia. Conclusions: Graphic perseverations are frequent in both Alzheimers disease and vascular dementia. Frontal-executive defects can hamper inhibition of iterative graphic productions. Identification of graphic perseverations can be useful for detection and monitoring of frontal-executive impairments throughout the disease course in individuals with dementia.