Dementia is categorized into four types that include mixed dementia, synucleinopathy, tauopathy, and vascular dementia and vascular cognitive impairment, according to the National Institute on Aging. Alzheimer's disease is the most common form of dementia, accounting for 60 to 80 percent of dementia cases.
Alzheimer's is in the tauopathy classification, and it occurs when protein deposits block nerve cells. Vascular dementia represents the second most frequent form of dementia and results when vessels are damaged, blocking adequate blood flow to the brain, explains the NIA. Lewy body dementia and Parkinson's disease dementia are forms of synucleinopathy. Mixed dementia is the presence of symptoms from multiple forms of dementia simultaneously.