Decreased beta-amyloid1-42 and increased tau levels in cerebrospinal fluid of patients with Alzheimer disease.

Context: Alzheimer disease (AD) is characterized by pathological results at autopsy of amyloid plaques and tau-associated neurofibrillary tangles, but the clinical diagnosis of AD is determined on the basis of medical history, cognitive symptoms, and exclusionary criteria. The search for antemortem biomarkers is intense and has focused on cerebrospinal fluid (CSF) beta-amyloid1-42 and tau proteins.

Objectives: To compare CSF beta-amyloid and tau levels in a new population of AD patients and controls.