Mixed Dementia

Mixed dementia is a condition in which abnormalities characteristic of more than one type of dementia occur simultaneously. Physicians may also call mixed dementia "Dementia – multifactorial."

About mixed dementia

In the most common form of mixed dementia, the abnormal protein deposits associated with Alzheimer's disease coexist with blood vessel problems linked to vascular dementia. Alzheimer's brain changes also often coexist with Lewy bodies. In some cases, a person may have brain changes linked to all three conditions  — Alzheimer's disease, vascular dementia and dementia with Lewy bodies.

Researchers don't know exactly how many older adults currently diagnosed with a specific type of dementia actually have mixed dementia, but autopsies show that the condition may be significantly more common than previously realized.

Symptoms

Mixed dementia symptoms may vary, depending on the types of brain changes involved and the brain regions affected. In many cases, symptoms may be similar to or even indistinguishable from those of Alzheimer's or another type of dementia. In other cases, a person's symptoms may suggest that more than one type of dementia is present.

Causes and risks

Although mixed dementia is infrequently diagnosed during life, many researchers believe it deserves more attention because the combination of two or more types of dementia-related brain changes may have a greater impact on the brain than one type alone. Evidence suggests that the presence of more than one type of dementia-related change may increase the chances a person will develop symptoms.

Many researchers are convinced that growing understanding of mixed dementia, coupled with recognition that vascular changes are the most common coexisting brain change, may create an opportunity to reduce the number of people who develop dementia. Controlling overall risk factors for diseases of the heart and blood vessels may also protect the brain from vascular changes.