THE CLINICAL EVALUATION used to diagnose Alzheimer disease (AD) and other forms of dementia is often perceived as cumbersome because it places high demands on expertise and time. This perception has spurred research into biomarkers for AD, with 2 main areas of focus: (1) imaging of brain structure, metabolism, and activation and (2) measurement of proteins in the cerebrospinal fluid (CSF). In many studies, these techniques have attained high sensitivity to distinguish patients with AD from controls. However, the clinical diagnosis of dementia, made by a physician armed with little more than a pencil and paper, remains the gold standard. Dementia specialists can diagnose AD with great accuracy, predicting AD lesions at autopsy in about 90% of cases.1 Nonspecialist physicians are often cited as having lower diagnostic accuracy for AD, but this includes failure to screen for dementia or to carry out a systematic clinical evaluation because of factors such as lack of time. Can expert physicians or nonspecialists be persuaded to use biomarkers as tools to help diagnose AD? This depends on their clinical abilities and available time, the perceived importance of accurate diagnosis, and practical issues surrounding the biomarker including ease of acquisition and interpretation, speed, and cost.
Galasko D. Cerebrospinal Fluid Biomarkers in Alzheimer DiseaseA Fractional Improvement?. Arch Neurol. 2003;60(9):1195-1196. doi:10.1001/archneur.60.9.1195