Assessing and predicting functional impairment in Alzheimer's disease: the emerging role of frontal system dysfunction.

Alzheimer's disease (AD) is associated with neuropsychologic and neuropsychiatric dysfunction and is a leading cause of disability among the elderly. Impairments in activities of daily living (ADL) contribute significantly to the disability reported among patients with AD and diminish quality of life for patients and their families. ADL assessment represents an important component of the diagnosis, tracking, and management of AD. Further, an understanding of the determinants of ADL dysfunction is critical for the early identification of individuals at risk for functional disability and for improved patient care. This manuscript reviews methods for assessing ADL in patients with AD and summarizes the available literature on the neuropsychologic and neuropsychiatric correlates of functional impairment in AD. The emerging role of frontal system dysfunction as an important determinant of ADL impairment is discussed, and recommendations for clinical practice and future research are provided.