The current issue of Aging Well (January/February 2013) has an article titled "Can You Recognize Lewy Body Dementia?" It is written by a doctor for other doctors (geriatric professionals) and it points out that LBD is often misdiagnosed and that has consequences for the treatment plan.
It is written for professionals but I don't think it is too technical for us lay people.
It is available online. Copy this in the search box (Google or other) and you should be able to find it easily: Can You Recognize Lewy Body Dementia? By Charles E. Driscoll, MD, with Jean Driscoll
If you suspect your loved one might have this version of dementia, you might find it helpful to bring the article to the doctor's attention. (Getting a good diagnosis for someone with LBD can be a frustrating experience!)