Bruce Willis.Photo: Frank Micelotta/Picturegroup/Shutterstock

Bruce Willishas beendiagnosed with frontotemporal dementia, wifeEmma Heming Willis, announced on Thursday, revealing that his condition has worsened since his family first shared news of hisaphasia diagnosislast year.
“Since we announced Bruce’s diagnosis of aphasia in spring 2022, Bruce’s condition has progressed and we now have a more specific diagnosis: frontotemporal dementia (known as FTD),” Emma wrote. “Unfortunately, challenges with communication are just one symptom of the disease Bruce faces. While this is painful, it is a relief to finally have a clear diagnosis.”
While FTD is often confused with Alzheimer’s Disease, Dr. Allison Reiss, an expert on dementia-related illnesses who is a member of the Alzheimer’s Foundation of America’s Medical, Scientific and Memory Screening Advisory Board, tells PEOPLE about the major differences between the two diseases.
Frontotemporal dementia (FTD) is an all-encompassing term for a group of brain disorders that threatens thefrontal and temporal lobes of the brain. This means that parts of these lobes atrophy, and the shrinking of these areas can cause speech issues, emotional problems and changes in personality.
Never miss a story — sign up forPEOPLE’s free daily newsletterto stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.
The key difference between Alzheimer’s and FTD is that there are no amyloid plaques with FTD.
“Amyloid plaque is a protein that is normal to have, but what happens in Alzheimer’s is it kind of clumps and gathers, and you can see it on positron emission tomography (PET) scans,” Reiss explains. “Amyloid sits in the brain, in the spaces between nerve cells, you can see it, and it seems to be part of the destructive process. You don’t see that with FTD.”
“Unfortunately, though, the end result is the same,” Reiss adds of FTD and Alzheimer’s. “You end up losing so much of your brain that you end up in a vegetative state. This is a very sad reality, it only goes downhill. Everyone wants to know what the cure is; what the treatment is: Nothing. We can’t really do anything to stop the progress.”
Reiss described some of the symptoms of primary progressive aphasia, the category of FTD she believes Willis is experiencing.
“These are people who don’t understand words anymore. They lose the ability to name things, or they can’t come up with the right name for things. As it progresses they don’t know what words mean anymore,” she explained.
“They forget the name of familiar objects — they’ll call a bowl a plate, or a fork a knife; they just aren’t able to get the right word. At first, they knowwhatthey want to say, but with progression, they lose the meanings of words.”
The causes of FTD are largely unknown, but somegenetic mutationshave been linked to the disease. However, more than half of people with the condition have no family history of dementia. Patients typically begin to notice symptoms between 40 - 65 years of age, but it can affect people who are younger. It is the most common form of dementiafor people under 60.
There is no single test to diagnose the disease, so doctors must evaluate patients' reflexes, memory and problem solving skills among other health factors to come to a diagnosis. An estimated 50,000 to 60,000 people in the U.S. have been diagnosed with an FTD disorder, according toThe Association for Frontotemporal Degeneration.
There are currently no treatments or a cure for FTD, but medications may aid with the symptoms.
source: people.com