Executive function: The core feature of dementia?

Links between Alzheimer's disease (AD) and vascular dementia (VaD) have been examined, and this paper investigates the role of executive control function (ECF) within the dementia syndrome. 307 AD patients, 168 VaD patients and 208 controls were compared on tests of cognitive function. Results indicated that controls outperformed both patient groups (p<0.001) on all tests. AD patients performed more poorly than VaD patients on 11 of the 18 cognitive tests (p<0.05). Factor analysis of patient data indicated the existence of 3 factors generated from the battery of tests, relating to episodic memory, ECF and face recognition. It was primarily on tests of ECF that the AD and VaD groups did not differ significantly. It is concluded that ECF is a feature of cognition shared by the two pathologies, giving rise to an obligation to reconsider the current understanding of the core cognitive feature of dementia.