Seeking reversibility and treatability in dementia.

The search for "reversible causes" in the patient presenting with dementia has become a routine part of medical care. This article reviews evidence as to the prevalence of reversibility and concludes that actual reversal of dementia by treatment is rare. In this context, the utility of specific laboratory investigations is discussed, and commonly sought conditions, such as normal-pressure hydrocephalus and B12 deficiency, are reviewed. Overemphasis on reversibility risks neglect of the assistance physicians can provide to patients suffering from irreversible conditions and their families.