Because biomarkers to detect Alzheimer’s disease (AD) have not yet been validated, physicians must rely on clinical assessments. The Research Committee of the American Neuropsychiatric Association recommended that the ideal cognitive screening instrument have the following characteristics: First, it should take <15 minutes to administer by a clinician at any level of training. Second, it should sample all major cognitive domains, including memory, attention/concentration, executive function, visual-spatial skills, language, and orientation. Third, it should be reliable, having adequate test-retest and inter-rater validity. Finally, it should be able to detect cognitive disorders commonly encountered by neuropsychiatrists.
The American Academy of Neurology Practice Parameters from 1994 and 2001 and the Canadian Consensus Guidelines on Dementia from 2007 recommend that physicians screen subjects with suspected dementia or mild cognitive impairment (MCI), since these patients are at increased risk for AD. Currently, there are no data on the utility of screening subjects who are asymptomatic.
The most commonly used brief cognitive tests are the Mini-Mental State Examination (MMSE), according to a survey conducted by the International Psychogeriatric Association (IPA) in 2006, followed by the clock-drawing test, the delayed-word recall, the verbal fluency test, the similarities test, and the trail-making test. Clinicians appraised these assessments as the most effective and easiest to administer (Slide 1).