The diagnosis of reversible dementia in the elderly. A critical review.

Evaluation of the elderly demented patient includes a search for treatable diseases; recommendations for this approach have been based on reports of a high prevalence of "reversible" dementia in several series of patients in the medical literature. A critical review of the methodology of these reports was undertaken to determine their validity as sources for the protocols often recommended. Several methodologic flaws were found in many studies that recommended extensive "screening" of the demented elderly, limiting their usefulness as resources. More carefully designed studies are needed to understand better the frequency and etiology of reversible causes of dementia.