Bruce Willis' wife says it is "hard to know" if the award-winning actor is aware of the frontotemporal dementia he was diagnosed with earlier this year.

Emma Heming Willis sat down with "Today" show co-anchor Hoda Kotb Monday to provide an update on the "Die Hard" star, share her journey as a "care partner" and elevate awareness of the disease at the start of World Frontotemporal Dementia Awareness Week.

"It was a blessing and a curse to finally understand what was happening to him so I can be into the acceptance of what it is," Heming Willis, 45, said. "It doesn't make it any less painful, but just being in the know of what is happening to Bruce makes it a little bit easier."

There is no treatment or cure for the disease, which Association for Frontotemporal Degeneration CEO Susan Dickinson said during the segment could be passed on genetically in about 20-25% of people, but is also "sporadic," meaning medical professionals don’t know what causes the condition.

In 2022, Willis, 68, was diagnosed in 2022 with aphasia, which affects how a person communicates, especially using speech. In February, Willis' family announced that the condition had progressed to frontotemporal dementia.

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How is frontotemporal dementia diagnosed?

The diagnosis is tricky, Dickinson explained, because the disease often presents as depression, bipolar disorder, Alzheimer's Disease or ALS (amyotrophic lateral sclerosis), commonly known as ALS. It can take almost four years for someone to be properly diagnosed, she said.

"We're talking unexplained changes in how a person is in the world,” Dickinson said. "Someone who speaks fine has trouble putting thoughts into a sentence or may lose the meaning of a word or has problems at work, either making poor decisions or not completing tasks."

No 'stigma or shame' in Bruce Willis' diagnosis

Heming Willis, who married the superstar of more than 100 movies including "Armageddon," "The Sixth Sense" and more recently, "Paradise City" and "Motherless Brooklyn," in 2009, shares two daughters with him: Mabel Ray, 11, and Evelyn Penn, 9.

Willis also shares three adult daughters with ex-wife Demi Moore – Rumer, Scout and Tallulah Willis.

Heming Willis said theirs is "a very honest and open" household – "I wouldn’t want there to be any stigma or shame for their dad's diagnosis or any form of dementia" – and noted how her husband’s condition has impacted their daughters.

"He is the gift that keeps on giving. Love, patience, resilience. So much that he's teaching me," she said. "And it's teaching (our kids) so much. How to care, how to love. It’s a beautiful thing amongst the sadness."

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