Introduction
Dementia is a general term for impaired ability to think, reason, and remember to the extent that it interferes with daily life and activities. Several factors and disorders contribute to the development of dementia. There are different types of dementia. One of them is mixed dementia. Mixed dementia, vascular dementia, and Alzheimer’s dementia are the most frequent types of dementia that can be related to each other.
What Is Mixed Dementia?
Mixed dementia is the coexistence of two or more types of dementia in the same demented patient. The most common combination of mixed dementia is Alzheimer’s disease and vascular disease. Approximately one in every ten individuals with dementia is diagnosed with more than one type. Mixed dementia is more common in the aged population over 75 years of age. Currently, diagnosing and treating mixed dementia is challenging for practitioners. Practitioners tend to use the term mixed dementia when an individual has clear signs of two types of disease that directly contribute to dementia symptoms. Although many aged people have both Alzheimer's disease and vascular disease, very few are diagnosed with mixed dementia.
What Are the Symptoms of Mixed Dementia?
The symptoms of mixed dementia vary depending on the part of the brain affected, the type of brain changes, and the type of dementia. Many cases have symptoms similar to Alzheimer’s disease or other types of dementia. In other cases, a person may experience symptoms suggestive of more than one type of dementia. In a person with two types of dementia, the symptoms are more noticeable and appear to progress rapidly.
What Are the Common Types of Mixed Dementia?
Rarely, mixed dementia is a combination of three types of dementia-causing diseases. Most cases tend to be a combination of two types. The most common types of mixed dementia include:
1. Alzheimer’s Disease and Vascular Disease
Alzheimer’s and vascular disease combination type of mixed dementia is the most common type. The affected people have two different conditions in the brain contributing to symptoms of dementia. Alzheimer’s disease is caused due to build-up of faulty proteins in and around brain cells, especially brain cells that contribute to forming memories. The initial stages of Alzheimer’s disease are associated with language difficulties, memory problems, and becoming confused more easily.
The vascular disease in mixed dementia is caused by obstructive blood supply throughout the brain. It can be caused due to stroke or a series of mini-strokes, or it can be due to the gradual deterioration of small blood vessels over the years. The vascular disease causes a lack of oxygen and nutrients in the brain cells necessary for proper functioning. The signs and symptoms of vascular disease depend on what part of the brain is affected. It results in slower processing of thoughts and information, trouble concentrating for more than a short period, and difficulties with problem-solving and planning.
2. Alzheimer’s Disease and Lewy Body Disease
Alzheimer’s disease and Lewy body disease combination type of mixed dementia are seen less often. Lewy bodies are faulty protein clumps that build up in the brain cells in people suffering from Parkinson's disease or dementia with Lewy bodies. Lewy body disease has distinct symptoms not seen in other dementias. It affects various parts of the brain, controlling body movement and processing sensory information. Affected people often experience very disturbed sleep and visual hallucinations. They also experience fluctuations in the ability to function properly and feel disoriented or confused suddenly. Memory is less affected in such people when compared to people with Alzheimer’s disease.
How to Diagnose Mixed Dementia?
In several cases where autopsy results showed the presence of mixed dementia, people in those cases were originally diagnosed with one type of dementia during their life, especially Alzheimer’s disease. The most common coexisting condition was previously undiagnosed blood clots or other signs of vascular disease. Lewy body disease was the second most common coexisting brain problem. Research shows that mixed dementia is often not diagnosed and recognized properly, with people diagnosed with one type of dementia. Also, an inaccurate diagnosis can lead to the diagnosed person not getting proper interventions that could be helpful for unrecognized diseases.
What Are the Treatment Options for Mixed Dementia?
As of now, there is no cure for any dementia, including mixed dementia. Medications and other treatment options help to maintain a better level of cognitive function. But it does not stop the underlying damage to the brain.
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Medications - Cholinesterase inhibitors are the most common type of medication used in the treatment of mixed dementia. Donepezil, Galantamine, or Rivastigmine are cholinesterase inhibitors that can be prescribed. They boost the levels of a chemical present in the brain that helps brain cells to communicate with each other. Sadly there is currently no medicine available that alleviates or improves the symptoms of vascular dementia. People with vascular disease can prevent strokes or other events by taking medications for high blood pressure.
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Therapies for Mixed Dementia - Along with medications, there are other therapies that can help improve the quality of life and function of the affected people. It includes cognitive stimulation therapy, cognitive behavioral therapy, and reminiscence therapy. There are different approaches that can help in coping with memory loss, such as exercise, yoga, meditation, socializing, getting organized, eating a healthy diet, sleeping properly, and staying mentally active by solving puzzles, etc. Physiotherapy can help with movement problems in people having mixed dementia involving Lewy body disease.
Conclusion
Mixed dementia is less often diagnosed during life, and many researchers believe that it needs more attention. Proper diagnosis is required because a combination of two or more types of diseases causing dementia-related brain changes have a huge impact on the brain than one type alone. Controlling the risk factors for conditions of the heart and blood vessels, such as blood pressure, body weight, cholesterol levels, and diabetes, can protect the brain from vascular changes.
