Clinical and pathological examples of Alzheimer's disease, dementia with Lewy bodies, and frontotemporal dementia.

Dementia syndromes usually consist of distinct clinical and pathological phenotypes. A careful history is required to document the onset and progression of symptoms to generate the differential diagnosis. New biomarker tests can provide evidence to increase diagnostic certainty. Disease-specific interventions, based on advances in genetic and molecular biomarkers, are likely to have the greatest impact when given in preclinical and early symptomatic phases.