It is often difficult for physicians to diagnose Lewy body dementia because it is similar to Alzheimer’s and Parkinson’s diseases and because a patient may actually have a combination of these diseases. A person with Lewy body dementia may be diagnosed as having Alzheimer’s disease or vascular dementia when symptoms first appear.
Although there are no specific tests for Lewy body dementia, doctors can make a diagnosis based on symptoms and behaviors. For diagnosis, patients must have experienced a progressive or continuing decline in the way they are able to function in daily life. If this requirement is met, then a person may either be diagnosed as having "probable" Lewy body dementia or "possible" Lewy body dementia. A diagnosis of probable Lewy body dementia requires that 2 of the 3 following characteristics be present. A diagnosis of possible Lewy body dementia only requires that 1 of the 3 are present (Merck, 2007).
Merck and Company. Dementia: Delirium and Dementia. 2007. Available at: http://www.merckmanuals.com/professional/sec16/ch213/ch213c.html. Retrieved March 30, 2009.
Description: This web page on diagnosing Lewy body dementia discusses the different tests that should be performed before making a diagnosis of Lewy body dementia; however, a definitive diagnosis of Lewy body dementia is only possible after death.
Source: Family Caregiver Alliance (FCA)
Description: This web page provides a thorough and easy-to-read discussion of dementia with Lewy bodies that includes basic facts about the disease, information on symptoms, diagnosis, and treatment, and comparisons to other forms of dementia.