Bruce Willis' wife revealed this week how the first subtle sign her husband had dementia was problems with his speech - which his family wrote off as part of his lifelong stutter.
Emma Heming Willis, 46, said while the action movie star had always had the stutter, he largely kept it under control thanks to techniques he learned from acting.
But in the months before he was diagnosed with frontotemporal dementia, he became not as 'good at covering it up.'
Known as aphasia, the loss of ability to understand or express speech is often one of the first signs of dementia, striking years before an official diagnosis.
Now, Dr Stuart Fischer, a New York City internal medicine specialist, told DailyMail.com President Joe Biden's speech patterns are consistent with aphasia.
Dr Fischer said: 'Since his recent presidency, he's had many other neurological problems.'
Similar to Willis, President Biden also had a stutter growing up but rarely showed during his 36-year career in the senate and eight years in the office as Vice President.
However, in recent years, Biden has shown signs of deterioration, confusing words, taking long pauses in his speeches and stuttering more dramatically.
Dr Stuart Fischer met Bruce Willis backstage after the actor performed in the Broadway adaptation of Stephen King's Misery
Willis starred in blockbusters like Die Hard, Pulp Fiction and the Sixth Sense. He was diagnosed with frontotemporal dementia in 2023, but his family said he had been declining privately before then
Concerns about Pres Biden's speech have not subsided since he dropped out of the presidential debate. The 81 year old insists he is in perfect health, and white house doctors said his neurological exams showed that Pres Biden, 'demonstrates excellent fine motor dexterity'
Most recently, while attempting to call out racist remarks made by a comedian at a Trump rally, Pres Biden stuttered, and then called Trump supporters garbage.
He said: 'The only garbage I see floating out there is his supporters, his, his demonization of Latinos is unconscionable, and it's un-American. It's totally contrary to everything we've done, everything we've been.' His campaign has since said the President Trump himself.
Heming Willis told Town & Country that she had seen little changes in his behavior for a long time before he was diagnosed with aphasia in 2022, but it was so subtle and slow that it's difficult to pinpoint when the disease became severe.
'Bruce has always had a stutter, but he has been good at covering it up. As his language started changing, it [seemed like it] was just a part of a stutter, it was just Bruce.
'Never in a million years would I think it would be a form of dementia for someone so young.'
The British-American model added: 'I say that FTD whispers, it doesn’t shout. It’s hard for me to say, "This is where Bruce ended, and this is where his disease started to take over."'
In the spring of 2022, Willis was diagnosed with aphasia.
There are many different causes for aphasia, including stroke, head injury and brain tumor.
It can also be the first signs of different types of neurodegenerative diseases, from Alzheimer's to ALS, or in Willis' case, frontotemporal dementia.
Dr Fischer said that it does appear Biden seems to be dealing with aphasia, but that it's likely not from the dementia that Willis is suffering with.
He said it could either be associated with normal memory loss during old age or another kind of dementia, but it's impossible to diagnose without seeing him in person.
Fischer added: 'Usually when people become as people age, they develop what's called vascular dementia.
'And that is definitely a cognitive problem. Memory gets lost. Memory might be very bad, people struggle for words... these are things we associate with the normal aging process.'
Frontotemporal dementia is a relatively rare form of the disease - thought to only affect an estimated 60,000 Americans.
Heming Willis frequently appears at advocacy events for the disease, and said: 'it’s this underdog of a disease, and I don’t know why. Now I am raising my voice and trying to have legislators hear the definition of what FTD is and realize there is so much work to do.
It tends to be diagnosed in younger people than in other dementias. According to the NIH, 60 percent of people with the condition are between 45 and 64 years old.
Other early symptoms of the disease include apathy, behavior changes, like an increase in impulsivity and issues with decision making.
As the disease progresses, it can rob people of their speech, cause seizures, limit their mobility and stop them from controlling bodily functions - essentially confining them to bedrest, according to Athena Healthcare Group.
Because the disease is rare, it's understudied, and there are no treatments for it.
Once someone is diagnosed, they may live more than 10 years with the disease, or in some cases, less than two years, passing away from other conditions like pneumonia, infection or a fall.
Pres Biden has not been diagnosed with any neurodegenerative disease, yet critics have long levied concerns that he is mentally fit enough to hold the executive office.
These concerns exploded into the public in June when Pres Biden debated former President Donald Trump.
In the course of the 90 minute debate, Pres Biden appeared to lose his train of thought and have difficulty finding the correct words multiple times.
He also spoke in long, disjointed sentences that made little sense a number of times.
This led to a maelstrom of criticism about his fitness, that likely contributed to his decision to drop out of the presidential race in July.
In recent appearances, Pres Biden has had similar issues with his speeches. At an October 25th speaking event on the Gila River Indian Community Arizona, he struggled to pronounce the name of the community.
The Delaware native has refused to take cognitive tests publicly and has refuted all suggestions of mental decline.
White House representatives said the President has seen a neurologist three times tied to an annual physical exam for someone of his age, and that his results indicated he was in good cognitive health.
However, authorities like the Alzheimer's Society caution that only a clinical assessment from qualified doctor can diagnose someone with dementia.
The organization said: 'it’s right that voters should be able to discuss a candidate’s perceived mental and physical fitness for such an important role, it’s not right to speculate that someone specifically has dementia or a mental health condition.'