Different types of dementia, their symptoms and causes. And what you can do to reduce your risk.
We’ve listed the most common types of dementia here, along a short description of their symptoms and causes, and resources where you can go for more information.
Mild Cognitive Impairment (MCI) - This is often the first diagnosis people receive. It is a precursor to Alzheimer’s disease, but not everyone who has MCI will go on to develop Alzheimer’s.
- Symptoms: Memory loss – Slight but noticeable decline in memory and thinking skills.
- Cause: The cause of the MCI is not usually apparent.
Alzheimer’s Disease (AD) - This is the most well-known dementia and the most commonly diagnosed. AD usually becomes apparent when people are in their mid-60s, although early-onset AD has been diagnosed in people whose ages have ranged from the mid-30’s to mid-60’s. However, early-onset AD is rare. AD is progressive, meaning that symptoms become worse over time. Most people live five to ten years after diagnosis.
- Symptoms: Memory loss, confusion, difficulty communicating, paranoia, anxiousness. People can become irritable or aggressive as confusion increases.
- Cause: AD is caused by amyloid plaque deposits and by tangled fibers from another protein (tau). These proteins cause neurons to lose their connections and they can no longer communicate with one another. As the disease progresses, the brain shrinks and loses mass.
Vascular Contributions to Cognitive Impairment and Dementia (VCID) - This is the second most common type of dementia, caused by damage to the blood vessels supplying oxygen to the brain. VCID can occur anywhere in the brain, and can be brought on either gradually or suddenly. People may possibly improve somewhat during recovery and rehabilitation after a stroke, if they are able to generate new brain cells and blood vessels.
- Symptoms: People have problems with language, attention and the ability to focus, think and reason. The symptoms will vary according to the part of the brain that is affected.
- Causes: VCID can begin gradually, brought on by many small strokes, or be brought on suddenly when the flow of blood to the brain is interrupted such as in a transient ischemic attack or large stroke. It can also be caused by the same underlying conditions that would cause a stroke, such as high blood pressure, high cholesterol or atrial fibrillation, causing damage to blood vessels and reducing the delivery of oxygen to the brain. This type of damage would be more gradual. The diagnosis is often confirmed when vascular damage is revealed by an MRI scan of the brain.
Lewy Body Dementia (LBD) - LBD is the third most common type of dementia. LBD is thought to be linked to Parkinson’s Disease, and Parkinson’s Dementia, as they all have Lewy Bodies, a type of abnormal protein deposit, that are present in the brain.
- Symptoms: Sleep disturbance and sleep loss, visual hallucinations and difficulty paying attention or focusing on tasks. Other symptoms include slowness of movement, stiffness or tremor. Memory loss is not always apparent in the early stages of LBD.
- Cause: LBD is caused by abnormal protein deposits in the brain, called Lewy Bodies, composed of alpha-synuclein protein. These deposits affect chemical interactions in the brain, which in turn affect how brain cells interact with each other.
Frontal-Temporal Dementia (FTD) - FTD initially impacts the frontal and temporal lobes of the brain. The basic cause for FTD is the damage to neurons, and/or loss of connections in those lobes, but there are many underlying causes for that damage. The initial symptoms of this type of dementia tend to be changes to personality and behavior, rather than memory loss. This is believed to be the fourth most common type of dementia. FTD can appear anytime between the ages of 20 and 80 years, but most commonly is diagnosed in people aged 45-60 years old. People live an average of 10 years after being diagnosed with FTD.
- Symptoms: Decreased inhibition, sometimes leading to inappropriate behavior. Compulsive, repetitive behaviors may also appear. Other emotions may be affected, people may become apathetic and lose their motivation, or may become less empathetic. Language and communication may be affected as well. Memory is not always affected in the earlier phases of FTD.
- Causes: As noted above, the primary cause of FTD is loss of nerve cells in the frontal and temporal lobes of the brain. Two proteins are the main causes of FTD – Tau proteins and TDP43, but it has not yet been determined why these two proteins are drawn to attack those areas of the brain. Injury and degenerative diseases such as ALS also may cause FTD.
Other forms of dementia that are less common -
- Prion diseases such as Cruetzfeld-Jacob disease where proteins begin abnormally folding. This type of dementia usually progresses very fast once it begins. The condition may be inherited or a person may acquire it by being exposed to damaged prions in nerve tissue such as in a corneal transplant or by eating brain and spinal tissue that has folded prions (mad cow disease).
- Downs Syndrome – as more people with Downs are living longer lives, they are developing a dementia very similar to Alzheimer’s.
- Chronic traumatic encephalopathy (CTE) caused by repeated traumatic brain injury. This type of dementia affects athletes who play high-contact sports like football.
- HIV-related dementia.
- Huntington’s disease – an inherited disease.
- Alzheimer’s Association
- National Institute on Aging
- National Institute on Aging Cognitive Health
- National Institute on Aging Alzheimer’s and Related Dementias
How Can Dementia be Prevented?
Now you’re probably thinking about how to prevent dementia. There is no known way to prevent dementia at this time, but the good news is that there is a lot you can do right now that will help to preserve your health as you grow older. Bonus point – these activities are not just good for brain health, they are good for your health overall. For example, regular exercise will help you to maintain your balance, strength, stamina and flexibility, making it easier to do everyday tasks such as unloading groceries or even just getting up out of a chair:
- Don’t smoke, or quit now.
- Maintain blood pressure, cholesterol and blood sugar within accepted limits.
- Eat a healthy, balanced diet. Physicians recommend a Mediterranean diet (link) as being good for health (and it’s delicious).
- Exercise regularly. Even just 30 minutes per week or walking 10 minutes every day will have a positive impact.
- Maintain a healthy weight.
- Limit alcohol consumption.
While there is no way to improve cognitive ability or reverse dementia, there are some activities that may have some positive effect on cognitive ability. The key is to use a mixture of diet, exercise and activities like the ones listed here:
- Maintain social contacts with family and friends.
- Learn to play a musical instrument.
- Learn a new language.
- Pick up a new hobby.
- Play games on a Wii, where physical activity is required.
- Do Sudoku puzzles.
Is There a Cure or Treatment that can Help?
Currently, there is no cure for dementia, and there are few treatments. There is a lot of research happening in this field, and you can help by volunteering to participate in a study. The Mesulam Center for Cognitive Neurology and Alzheimer’s Disease at Northwestern Hospital in downtown Chicago, is looking for people for ongoing or new studies. To volunteer, just visit their website and fill out the questionnaire.
Or look on the NIA Clinical Trial Finder for a trial near you.
If you, or someone you know has received a diagnosis of dementia, Argentium Home Care Aides have received specialized training in caring for people living with dementia. Learn more about our Caregivers.