Objective
To examine visuospatial impairment in a task that minimizes episodic memory demands in individuals with very mild or mild dementia of the Alzheimer type compared with a healthy control group.
Design
Initial scores on the Visual Form Discrimination Test enrolled in longitudinal studies of dementia of the Alzheimer type and healthy aging.
Setting
Alzheimer's Disease Research Center at Washington University, St Louis, Mo.
Participants
Volunteer samples of 59 people (35 women and 24 men) with mild dementia of the Alzheimer type, 66 (39 women and 27 men) with mild dementia of the Alzheimer type, and 146 healthy nondemented individuals (90 women and 56 men) were recruited between 1988 and 1992. Ages ranged from 51 to 96 years. Persons with confounding medical, neurologic, or psychiatric disorders were excluded. Dementia severity was staged by means of the Clinical Dementia Rating.
Main Outcome Measures
Total number correct on the Visual Form Discrimination Test as well as the numbers of three types of errors: peripheral figure movement or rotation, major figure distortion, and major figure rotation.
Results
Visuospatial deficit was apparent in very mild dementia of the Alzheimer type. Individuals with both very mild and mild dementia of the Alzheimer type made more errors involving peripheral figures and rotation of a major figure than did healthy, nondemented individuals.
Conclusion
The initial effects of Alzheimer's disease on cognitive function are more pervasive than just episodic memory failure.
