Bruce Willis' mother, Marlene Willis, has been experiencing how the movie star's illness has impacted on his life and the way he relates to the world around him.

Watch Bruce Willis' friend express concern about his diminished 'zest for life'

"She is not sure if her son still recognizes her," explained Wilfried Gliem, Willis' mother's cousin, in an interview with BILD.

"His behavior is very slow, there is always a slight aggressiveness and it is no longer possible to have a normal conversation with him.

"Although this behavior is usual in his clinical condition."

Gliem also said that Marlene is suffering a lot for her granddaughters, but she is confident that the family will be able to get through this difficult time together.

Bruce Willis' disease didn't come as a huge shock in Hollywood

Last Thursday, through a statement, it was reported that the health of Bruce Willis, who had to retire from acting after suffering from aphasia, had worsened in the last year.

After further tests, the actor was diagnosed with frontotemporal dementia.

Willis' current wife Emma Heming, his former wife Demi Moore, and the actor's five daughters, Rumer, Scout and Tallulah detailed the tough time he is going through at the age of 67.

"Since we announced Bruce had aphasia in 2022, his condition has progressed and we now have a more specific diagnosis: frontotemporal dementia (FTD)," the family statement read.

"Sadly, difficulty communicating is one of the symptoms of this disease he is facing. Although this is very painful, it is a relief to have a clear diagnosis.

"It is a cruel disease that many of us never hear about and it can strike anyone."