The diagnostic evaluation of a patient with dementia

This review outlines a practical approach to the history, mental state, neurologic examination, and laboratory tests in the diagnosis of dementia.

Proposed new diagnostic criteria for Alzheimer disease recognize that nonamnestic presentations with symptoms that predominantly affect language, visuospatial abilities, or executive function may occur, particularly with onset before the age of 65. New criteria assign greater likelihood to diagnosis if progressive cognitive decline is documented through serial assessment, or if biomarkers are supportive. In patients aged 80 or older, more than one cause of dementia is often present, for example, Alzheimer disease plus vascular dementia. Clinical diagnostic criteria for non-Alzheimer dementias are evolving, particularly in areas such as frontotemporal dementia. Imaging and CSF biomarkers have been proposed in recent diagnostic criteria for Alzheimer disease. Although biomarkers can provide a higher level of certainty that Alzheimer pathology may or may not be present, biomarkers for non-Alzheimer dementias are lacking.

The availability of biomarkers does not replace or diminish the need for a thorough clinical evaluation. A structured clinical approach helps to define the diagnosis and collects information essential for establishing a comprehensive care plan for patients with dementia and their families.