Differences between Alzheimer's disease and vascular dementia on information processing measures.

This study evaluated information processing differences between 30 vascular dementia (VaD) patients, 30 Alzheimer's disease (AD) patients, and 30 normal elderly (NE) controls. They were administered a complex reaction time test, a continuous performance test (CPT), and a neuropsychological battery. Compared to NE, both dementia groups had significantly slower motor reaction times and made more errors on the CPT. Compared to AD patients, the VaD patients were slower in stimulus categorization time and had increasing omission errors and persistent commission errors throughout the CPT trial, VaD, which usually includes frontal-subcortical circuit injury, can impair mental speed and stimulus response initiation.