The following is an excerpt from the Mayo Clinic Press book Mayo Clinic on Alzheimer’s Disease and other Dementias byJonathan Graff-Radford, M.D. and Angela M. Lunde, M.A.
Frontotemporal degeneration is one of the most common neurodegenerative dementia. It refers to a group of disorders that mostly affect the frontal and temporal lobes of the brain. These parts of the brain are used for language. They’re also linked to personality and behavior.
Major changes in personality and behavior are often seen in frontotemporal degeneration. Inappropriate actions, lack of empathy and lack of judgment are all examples.
Frontotemporal degeneration can also cause problems with language use, as well as issues with movement, like tremors.
Symptoms worsen over time. People with frontotemporal degeneration may have just one symptom in the beginning, but have many symptoms in later stages as more parts of the brain are affected.
Frontotemporal degeneration often affects adults at a younger age than Alzheimer’s disease does and can progress more quickly.
It’s also less common than Alzheimer’s disease. These are just two of many differences between Alzheimer’s disease and frontotemporal degeneration.
This type of dementia affects men as often as it does women, and nearly half of the people with it have a family history of some type of brain disease in a parent or sibling, including dementia, parkinsonism or amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease.
How quickly frontotemporal degeneration develops varies. Some people decline in two or three years, while others live with it for more than 20 years.
Signs and Symptoms of Frontotemporal Dementia
Signs and symptoms of frontotemporal degeneration affect people in different ways from those of other types of dementia.
First, they tend to change a person’s personality or language abilities. Second, these signs and symptoms often affect adults in the most active time of life, when they’re working and raising families.
Not everyone has all the signs and symptoms of frontotemporal degeneration or has them in the same way. In addition, the combinations of signs and symptoms in frontotemporal degeneration are many. However, there’s enough in common to allow for a general picture of what frontotemporal degeneration looks like.
Changes usually occur a little at a time, although some forms progress more quickly.
Early symptoms generally develop in one of three areas: personality and behavior, language and communication, or movement and motor skills. Behavioral and emotional changes usually take place before thinking skills decline.
Memory may not be affected for a long time. The same can be said for visuospatial skills, like moving about or judging the height of a step or navigating familiar places. Language issues can happen with any type of frontotemporal degeneration, but they tend to be a main symptom in primary progressive aphasia types of the disorder.
What causes frontotemporal degeneration
In most cases, what causes frontotemporal degeneration isn’t known. But as with Alzheimer’s, it’s linked to abnormal protein deposits in the brain. Instead of the amyloid protein, as in Alzheimer’s, many cases of frontotemporal degeneration show changes in the tau protein, which causes nerve cells to collapse and die.
The type of tau associated with frontotemporal degeneration is different from tau seen in Alzheimer’s disease. Researchers have found that a protein called TDP-43 is also linked to frontotemporal degeneration.
About half of the cases of behavioral variant frontotemporal degeneration are caused by TDP-43, and half are caused by tau. In rare cases, it’s caused by a protein known as fused in sarcoma.
Similar to the tau protein in Alzheimer’s disease, TDP-43 proteins cause nerve cells in the brain to stop communicating with each other and die. At this point, there’s no way of testing someone who’s living with frontotemporal degeneration to find which protein is causing it. This is a very active area of research.
Treating the Disorder
No treatment can cure frontotemporal degeneration or keep it from progressing. Therapies for these disorders are focused on symptoms and quality of life.
As with other types of dementia, researchers continue to study frontotemporal disorders to find medications that may help treat or prevent them in the future.
In particular, researchers are looking into how the disease develops so that when treatments are available, they can be directed to people when they can be most helpful.
What’s know about the gene and proteins involved in frontotemporal degeneration is evolving rapidly. This is leading to the development of new therapies. Most of these therapies are still in the early stages of development, which means it will take time before they can be tested in humans. But some are being tested in humans at specialized research centers.
Visit www.clinicaltrials.gov to learn more about what clinical trials are underway in frontotemporal degeneration.
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