International Work Group criteria for the diagnosis of Alzheimer disease.

Alzheimer-type biomarker changes are identifiable in asymptomatic and mildly symptomatic predementia phases of Alzheimer disease (AD) and AD dementia. The International Work Group (IWG) guidelines for diagnosis identify a unified spectrum of 3 phases. The classic clinical feature that indicates AD is an episodic memory defect of the amnestic type. IWG criteria require biomarker support for the diagnoses of AD at any clinical stage. Pathophysiologic and topographic biomarkers are recognized. These criteria are proposed to allow highly specific diagnosis of AD and assist in identifying patients for clinical trials of AD-related treatments and other types of AD research.