Target symptoms and outcome measures: Cognition

The Cognitive section of the Alzheimer's Disease Assessment Scale (ADAS-Cog) remains the most widely used cognitive measure in dementia trials although it does not assess attention, executive function, or agnosia. Designed for use in Alzheimer's disease (AD), it may not be ideal in assessing patients with other diagnoses. The ADAS-Cog differentiates between AD patients, patients with Mild Cognitive Impairment, and normal controls. It has been used in trials of drugs for vascular and mixed dementia and dementia with Lewy bodies. It is not clear that the ADAS-Cog is adequate for assessing cognition in frontotemporal dementia. Well-validated aphasia batteries, such as the Western Aphasia Battery, can be used to assess language. Brief tests of frontal function such as the Frontal Assessment Battery or the Executive Interview might be useful additions in frontotemporal dementia trials. The most widely used assessment tool for patients with advanced dementia is the Severe Impairment Battery. The domains tested are analogous to those assessed by the ADAS-Cog. The Mini-Mental State Exam and the Modified Mini-Mental State Examination are useful in stratifying patients for trial entry. Cognitive measures better tailored to the diseases in question are needed for non-Alzheimer dementias.