20. Visuospatial recall in cortical and subcortical dementias

Cortical and subcortical dementias differentially affect cognition with visuospatial sequencing particularly susceptible to damage in subcortical dementias. This study examined visuospatial memory and sequencing in cortical vs subcortical dementias. Recall of temporal presentation of visuospatial material was examined in Parkinson's disease (PD), Alzheimer's disease (AD), healthy elderly (HE), and healthy young subjects. Predictable pattern vs random sequences assessed ability to utilize pattern information to decrease the memory load of the task. Young subjects performed consistently better than the other groups on random trials. PD performance was consistent with the healthy older subjects. AD subjects were worse than the other groups on some trials. These results indicate that while AD subjects have a deficit in temporal ordering of visuospatial information relative to HE, PD subjects do not.