Dementia is a group of symptoms that affect your memory, cognitive abilities, and reasoning skills. What is mixed dementia, then? Mixed dementia is a combination of more than one form of dementia. When there is more than one form of dementia present in a patient, care is certainly complicated but there are some changes in caretaking that can make a big difference. How common is mixed dementia, though?
About one out of every 10 people who have a major neurocognitive disorder are diagnosed with mixed dementia. This condition is a combination of the disease processes of two different forms of dementia. Doctors sometimes also refer to this state as multifactorial dementia. Most common in people who are aged over 75, mixed dementia requires some changes from the usual standards of care to maximize the quality of life and longevity of the patient.
What exactly do you need to know about this unique type of dementia, how it can affect patients, and what you can do to help them? Keep reading to find out more about mixed dementia!
Common symptoms of mixed dementia
The most common form of mixed dementia is Alzheimer's disease with vascular dementia. Alzheimer's disease is accompanied by accumulation of tangled proteins that "strangle" neurons, primarily in the back of the brain. Vascular dementia is a complication of high blood pressure and bad cholesterol that causes transient ischemic attacks (mini-strokes) that damage vessels that carry blood to the front of the brain.
Mixed dementia presents the symptoms of both Alzheimer's and vascular dementia. Alzheimer's causes memory problems, loss of language, and confusion. Vascular dementia causes attention deficits, difficulty planning, and sluggish thinking. One set of symptoms may predominate at first, but all of them can occur at the same time.
Another relatively common form of mixed dementia is Alzheimer's disease with Lewy body dementia. Lewy bodies are abnormal proteins that form inside neurons. These changes produce symptoms similar to Parkinson's, while Alzheimer's follows a predictable progression of symptoms and disability. Lewy body dementia adds visual hallucinations and very disturbed sleep to the usual symptoms of Alzheimer's. Symptoms may fluctuate greatly from day to day in this combination of dementias.
The diagnostic dilemma in mixed dementia
How common is mixed dementia? Researchers don't really know, because precise diagnosis requires taking a sample of tissue from the brain of the person who has the disease. In a study involving autopsies of patients who willed their brains for study after death, however, 54 percent of people who had been diagnosed with Alzheimer's were found also to have brain changes from other forms of dementia, usually vascular dementia or Lewy body disease.
Treatments for mixed dementia
There is no cure for any kind of dementia. Some people do better longer, however, with good care and appropriate medications. So does a diagnosis of mixed dementia make any difference in care? It turns out that knowing that dementia is "mixed" can lead to appropriate steps to slow down the progression of the disease and increase quality of life.
- When there is vascular dementia, it is critically important to avoid new transient ischemic attacks and new vascular damage in the brain. That requires careful attention to managing cholesterol, keeping blood pressure within healthy limits, and using anticoagulant medications correctly to prevent new blood clots. These are not tasks dementia patients can achieve on their own. Healthy LDL and HDL levels are determined with reference to the presence or absence of diabetes. Studies show reduction in the rate of progression of vascular dementia when systolic blood pressure is kept below 130 mg/dl. Aspirin can be helpful in preventing Alzheimer's, but usually aspirin plus an anticoagulant (for example, clopidogrel, marketed as Plavix) is needed to see measurable, positive changes.
- Along with managing cholesterol, it is important to keep homocysteine levels normal. Homocysteine in excess produces hot spots of inflammation in the brain. To keep homocysteine down, it is necessary to get vitamins B6, B12, and folate. And to get B12, sometimes it is necessary to give the vitamin by injection, particularly in people who have digestive problems.
- In diabetic patients, good blood sugar regulation is critical. That means avoiding both chronically high blood sugar levels (the guideline is keeping HbA1C under 7.0 percent, although many diabetics have trouble meeting that goal) and especially avoiding hypoglycemia, blood sugar levels that fall so low as to cause loss of consciousness. Diabetes can cause "thinning" of the frontal cortex that precedes vascular dementia by up to 10 years. Blood sugar control today can prevent dementia progression years from now.
- Two studies show that diets providing vegetables, fruits, nuts, soy proteins, grains and fish slow the progression of Alzheimer's disease. Good diet won't reverse Alzheimer's, but it may slow it down.
- One study shows that getting at least 30 minutes of exercise at least three times a week slows the progression of both Alzheimer's disease and vascular dementia. It improves independence and makes daily activities easier.
Sources & Links
- Bogolepova AN. [A modern concept of mixed dementia]. Zh Nevrol Psikhiatr Im S S Korsakova. 2015.115(5):120-126. doi: 10.17116/jnevro201511551120-126. Review. Russian.PMID: 26356171.
- Zekry D, Duyckaerts C, Hauw JJ. [Vascular dementia and mixed dementia]. Presse Med. 2007 Oct
- 36.10 Pt 2):1469-76. Epub 2007 Jun 5. Review. French. PMID: 17553655.
- Zekry D, Hauw JJ, Gold G. Mixed dementia: epidemiology, diagnosis, and treatment. J Am Geriatr Soc. 2002 Aug.50(8):1431-8. Review. PMID: 12165002.
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