What does 'mixed dementia' mean?

Mixed dementia is a term used when someone has more than one type of dementia. Most commonly, mixed dementia is the terminology used when someone has been diagnosed with both Alzheimer’s disease and vascular dementia. However, it can also refer to a combination of Alzheimer’s disease and any other type of dementia. Physicians sometimes call this condition dementia-multifactorial.

The determination of mixed dementia is often hard to validate and is infrequently diagnosed. Traditionally, physicians identify the type of dementia — Alzheimer’s or vascular dementia.

However, researchers are increasingly discovering that people who have been diagnosed with one type of dementia may also have another kind. Alzheimer’s disease, vascular dementia and even Lewy body dementia have all been discovered in combinations through autopsies by researchers. In fact, one study by the National Institute on Aging revealed that of 94 percent of study participants who had been diagnosed with Alzheimer’s, 54 percent had another type of dementia.

Someone with mixed dementia usually exhibits the same symptoms of Alzheimer’s disease. These symptoms may progress faster or be manifested earlier because the brain is affected by more than one type of dementia or the brain is damaged in more than one area. The confirmation of mixed dementia is made after the person's death. The autopsy would reveal that the brain shows more than one type of abnormality such as a buildup of tau protein and blockages in brain vessels.

Oftentimes, when someone has a diagnosis of Alzheimer's disease with other issues, such as cardiovascular health problems, that would suggest vascular dementia, and the physician would make a diagnosis of mixed dementia. Advances in research and imaging techniques might provide better diagnostic tools so mixed dementia can be diagnosed long before an autopsy.

There are no approved drugs to treat mixed dementia, yet individuals with mixed dementia tend to respond favorably to most medications prescribed for Alzheimer's disease.

Questions about Alzheimer's disease or a related disorder can be sent to Dana Territo, the Memory Whisperer, director of services at Alzheimer's Services of the Capital Area at advice@alzbr.org or visit the organization at 3772 North Blvd., Baton Rouge.