Article / Updated 08-21-2016
Dementia can be broken down into the "big four:" Alzheimer's disease, vascular dementia, Lewy body disease, and frontotemporal dementia. Here is a quick guide to each. Alzheimer's disease Alzheimer's disease is the most common cause of dementia worldwide. In the United States, it's the cause of dementia in 62 to 80 percent of cases, accounting for the symptoms of more than 5.