Yahoo News How Bruce Willis' Diagnosis of Frontotemporal Dementia Differs from Alzheimer's Disease
Frank Micelotta/Picturegroup/Shutterstock
Bruce Willis has been diagnosed with frontotemporal dementia, wife Emma Heming Willis, announced on Thursday, revealing that his condition has worsened since his family first shared news of his aphasia diagnosis last 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 the frontal 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.
Alzheimer's is a degenerative brain disease that is caused by complex brain changes following cell damage. It progressively affects memory, thinking and behavior serious enough to interfere with daily tasks.
Never miss a story — sign up for PEOPLE's free daily newsletter to 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."
RELATED: What Is Frontotemporal Dementia? Everything to Know About Bruce Willis' Diagnosis
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 know what they want to say, but with progression, they lose the meanings of words."
The causes of FTD are largely unknown, but some genetic mutations have 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 dementia for 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 to The Association for Frontotemporal Degeneration.
There are currently no treatments or a cure for FTD, but medications may aid with the symptoms.
Following the Die Hard star's diagnosis, his family thanked fans for their support during the difficult time, vowing to raise awareness about the "cruel disease" FTD.
"Bruce always believed in using his voice in the world to help others, and to raise awareness about important issues both publicly and privately," Emma said. "We know in our hearts that – if he could today — he would want to respond by bringing global attention and a connectedness with those who are also dealing with this debilitating disease and how it impacts so many individuals and their families."
