Diagnosing Alzheimer Disease

ABSTRACT OBJECTIVE This article reviews the current understanding of Alzheimer disease (AD), including the natural history, common risk factors, and expected progression of AD neuropathologic change so that neurologists can apply this knowledge to identify patients with symptoms, signs, and findings on common diagnostic tests consistent with AD. LATEST DEVELOPMENTS The advent of potential disease-modifying therapies emphasizes the need to develop and deploy a practical and efficient approach to diagnose patients with cognitive impairment due to AD. ESSENTIAL POINTS The accumulation and spread of cerebral amyloid plaques and tau tangles in patients with AD leads to synaptic dysfunction, neuronal loss, and the eventual emergence and progression of cognitive impairment. A pragmatic and organized approach is needed to recognize patients with symptomatic AD in clinical practice, stage the level of impairment, confirm the clinical diagnosis, and apply this information to advance therapeutic decision making.