Emma Heming Willis is peeling back the curtain on life with Bruce Willis amid his frontotemporal dementia battle. In a clip from Emma and Bruce Willis: The Unexpected Journey - A Diane Sawyer Special shared on Good Morning America on Tuesday, August 26, Emma, 47, explained the first signs she recognized that her husband's behavior was changing. "For someone who is very talkative and very engaged, he was just a little more quiet," she said in the video. "And when the family would get together, he would kind of just melt a little bit." Host Diane Sawyer noted Bruce, 70, began "losing words" and a "childhood stutter reappeared," while his family members noticed he was becoming "less engaged in their lives." Bruce Willis' Daughters Praise Stepmom Emma Heming Willis' 'Bravery' "It felt a little removed, very cold, not like Bruce, who was very warm and affectionate," Emma continued. "To go in the complete opposite of that was alarming and scary." She further explained that not a lot of doctors know about frontotemporal dementia (FTD) or it is often misdiagnosed. Bruce's family first announced he was diagnosed with aphasia, a language disorder, in March 2022. Nearly one year later, they confirmed his condition progressed to frontotemporal dementia, which can affect a person's personality, behavior and language. "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," his family shared in a statement in February 2023. Bruce Willis and Emma Heming Willis Theo Wargo/Getty Images for Film at Lincoln Center Sawyer, 79, said that a brain scan confirmed Bruce had the brain disorder. "To leave there with no ... nothing, just nothing. With a diagnosis I couldn't pronounce. I didn't understand what it was," Emma said after hearing Bruce's diagnosis. "I was so panicked. I just remember hearing it and just not hearing anything else. It was like I was free-falling." When asked how Bruce reacted to his diagnosis, Emma said, "I don't think Bruce ever connected the dots." As for how Bruce is doing today, Emma said that her husband is "still very mobile" and "is in really great health overall." "It's just his brain that is failing him ... The language is going, and we've learned to adapt, and we have a way of communicating with him, which is just a different way," she said. Emma Heming Willis Says Bruce Willis Anniversary Brings 'Heaviness' Sawyer asked if there are days where Bruce acts like himself again around her and their daughters, Mabel, 13, and Evelyn, 11. (He also shares daughters Rumer, 37, Scout, 34, and Tallulah, 31, with ex-wife Demi Moore.) "Not days, but we get moments," Emma told Sawyer while choking back tears. "It's his laugh, right? Like, he has such a hearty laugh. And, you know, sometimes you'll see that twinkle in his eye, or that smirk, and, you know, I just get transported. And it's just hard to see, because as quickly as those moments appear, then it goes. It's hard, but I'm grateful. I'm grateful that my husband is still very much here." Emma and Bruce Willis: The Unexpected Journey - A Diane Sawyer Special airs Tuesday, August 26, at 8 p.m. ET on ABC.