Differential diagnosis of dementia: clinical examination and laboratory assessment.

Recent breakthroughs in putative disease-modifying interventions for Alzheimer's disease (AD) underscore the urgency of making the earliest possible diagnosis. In the absence of a convenient and reliable laboratory test for AD, the clinical assessment is still the cornerstone of the diagnostic approach. This article provides a basis for conducting an assessment within the realities of a busy clinical practice for patients complaining of cognitive decline. The assessment will enable the clinician to diagnose the earliest manifestation of AD.