Understanding Different Types of Dementia
By Julie Hayes | 02/15/2021
When most people hear the word “dementia,” one of the first things that comes to mind is “Alzheimer’s.” In common speech, the two terms are often used interchangeably, and when a person’s loved one shows signs of memory loss, it’s not uncommon for them to say, “I hope it’s not Alzheimer’s.”
However, Alzheimer’s is just one cause of dementia, which is the umbrella term for decline in memory, thinking and reasoning skills that significantly impacts daily life. If a loved one is experiencing memory issues, Alzheimer’s could be a potential diagnosis, but there are four other common types of dementia that should also be considered: Lewy body, frontotemporal, vascular and mixed.
Each variety of dementia has different characteristics, and for caregivers, knowing the difference can help in monitoring a loved one’s symptoms and accessing the right resources. Here is a breakdown of the five most common varieties:
Alzheimer’s Disease is the most common type of dementia, and according to the Alzheimer’s Association, it accounts for 60 to 80 percent of dementia cases. Alzheimer’s is a progressive brain disease that leads to broken connections between nerve cells and tissue shrinkage in parts of the brain necessary to memory functions.
Early signs and symptoms of Alzheimer’s vary from person to person, but can include difficulty finding words, confusion with time and place, trouble with judging distance and challenges in planning and decision-making.
2. Lewy body
Also known as dementia with Lewy bodies (DLB), this variety of dementia accounts for five to ten percent of dementia cases, according to the Alzheimer’s Association. It is marked by the presence of Lewy bodies—tiny deposits of protein—in the nerve cells in the brain. Lewy bodies are linked to the loss of connection between these nerve cells, as well as low levels of chemical messengers in the brain.
Because Lewy bodies are also present in Parkinson’s Disease, those with DLB may experience similar symptoms, such as tremors and other difficulties with movement, according to Family Caregiver Alliance. Those with Parkinson’s are also at high risk to develop DLB as their disease progresses.
Other common signs of DLB include sleep problems, hallucinations and difficultly maintaining attention.
Frontotemporal dementia (FTD) is a type of dementia that affects the frontal and temporal lobes of the brain, which are key to maintaining skills related to memory, language, judgment, problem-solving and behavioral and emotional regulation, according to Verywell Health. FTD was once thought to be the rarest form of dementia, but the Alzheimer’s Association now estimates that it makes up to 10 to 15 percent of dementia cases.
Because the frontal lobe plays an essential role in regulating emotion and self-control and guides us to behave in socially acceptable ways, early signs of FTD include changes in behavior, loss of emotional control and obsessive habits. Damage to the temporal lobe can cause language difficulties, so changes to speech patterns are also common to FTD.
Vascular dementia is the second most common variety of dementia, accounting for 20 to 40 percent of dementia cases, according to Verywell Health. Vascular dementia is caused by reduced blood supply to the brain due to blood vessels that are diseased, blocked, leaky or otherwise damaged. Without the necessary blood supply, brain cells die, resulting in decreased memory, thinking and reasoning skills.
Common early signs of vascular dementia include difficulty concentrating, slower speed of thinking, challenges following steps and problems with planning and decision-making.
Mixed dementia occurs when a person has more than one type of dementia. The most common type of mixed dementia is Alzheimer’s/vascular, with the next being Alzheimer’s/Lewy body. According to the Alzheimer’s Association, one in ten of people diagnosed with dementia has evidence of more than one type of dementia present. However, the exact number of cases of mixed dementia is unknown because it is not often diagnosed or identified until an autopsy is performed. Research suggests that it may in fact be quite common, but studies on the subject are still ongoing.
These five causes of dementia are the most common, but there are several additional diseases and conditions that can cause dementia as well. These include:
- Creutzfeldt-Jakob Disease: A rare and rapidly progressing brain disorder.
- Huntington’s Disease: A genetic disorder that breaks down nerve cells.
- Normal Pressure Hydrocephalus: A brain disorder caused by fluid buildup.
- Posterior Cortical Atrophy: A rare condition considered to be a variation of Alzheimer’s that causes decline in vision.
- Parkinson’s Disease Dementia: A result of brain changes caused by Parkinson’s Disease leading to the development of dementia.
- Korsakoff Syndrome: A chronic memory disorder caused by lack of Vitamin B1.
If you are caring for a loved one with dementia, it is important to familiarize yourself with which type of dementia your loved one has so you can be prepared for differences in symptoms and progression, while also knowing which disease-specific resources to access. If you’re not sure where to turn for guidance, here is a short-list of places to start:
- The Alzheimer’s Association
- Alzheimer’s Foundation of America
- Lewy Body Dementia Resource Center
- Lewy Body Dementia Association
- The Association for Frontotemporal Degeneration
- National Institute on Aging
- Family Caregiver Alliance
- U.S Department of Veterans Affairs
- Dementia Friends USA
- Benjamin Rose Institute on Aging
This article was written for the Expansion of Dementia-Capable Communities within Urban and Rural Settings in Ohio using Evidence-Based and Informed Programming project, a grant funded by the Administration for Community Living (ACL) . Learn more here.