Bruce Willis doesn't always recognise his daughter when she visits him, amid his battle with frontotemporal dementia (FTD)

She said in an Instagram Stories video: "I'm so happy and grateful that I still get to go and hug him.

"I'm so grateful that when I go over there, and I give him a hug, whether he recognises me or not, that he can feel the love I've given him, and I can feel it back from him.

"That I still see a spark of him, and he can feel the love that I'm giving.

"So that feels really nice.

"I just feel grateful that I get to go over there with Louetta and we get to spend time with him, and I get to feel the love that he has for me, and that I can love him and be with him."

Rumer - who has two-year-old daughter Louetta - admitted Bruce is "doing OK" amid his battle with the progressive neurodegenerative disease - a group of brain disorders affecting personality, behaviour, and language - but insisted anyone battling FTD is "not doing great".

When asked how her dad is doing, she replied: "People always ask me this question, and I think it's kind of a hard one to answer, because the truth is that anybody with FTD is not doing great.

"He's doing OK, in terms of somebody who is dealing with frontotemporal dementia.

"The only way that I feel like I could answer that in a way that was like, 'He's doing great!' ... You know, it's like, those parameters don't really work anymore I guess, in my mind, so this is always an interesting question."

Last month, Bruce's wife Emma Heming Willis admitted she and the Armageddon actor were left with "no hope, no direction [and] no support" when he was diagnosed with frontotemporal dementia.

She told Yahoo!: "The day we received the diagnosis, we walked out of that appointment with nothing - no hope, no direction, no support. I wasn't really given any information other than just the nuts and bolts of FTD.

"In looking back, I just think that's so crazy. It was such a traumatic experience, like your whole life is being ripped from you in a moment.

"After that appointment, I started digging into research online to really understand: What was this diagnosis? How does it impact my husband? How does it impact our family? With FTD, those early years are so hard because you're trying to figure it all out in real time and learning things on the fly. It's a progressive disease.

"So, in the beginning, your person can still manage some things, and then slowly the needs start changing and the things that they used to be able to do they can't do anymore. You have to rev up the support."