The neuropsychology of preclinical Alzheimer's disease and mild cognitive impairment

Subjects in the preclinical stages of Alzheimer's disease (AD) typically re cord neuropsychological performance between that of healthy older individua ls and demented patients. More specifically, deficits on measures of verbal episodic memory are commonly reported in these patients, while other cogni tive functions (e.g. language, praxis and executive function) seem to be sp ared. A similar neuropsychological profile is observed in elderly subjects with mild cognitive impairment (MCI), a disorder that is attracting increas ing research interest. Evidence from lesion and functional imaging studies, as well as volumetric imaging in probable AD and MCI patients, suggests th at the cognitive deficits observed in these disorders may be related to med ial temporal lobe dysfunction. An issue currently under investigation is wh ether MCI represents the preclinical stages of AD or a distinct and static cognitive aetiology. In an attempt to address this issue, present investiga tions are adopting a convergent approach to the detection of preclinical AD , where multiple risk factors are considered when making a diagnosis. (C) 2 000 Elsevier Science Ltd. All rights reserved.