Toto's Bobby Kimball Documentary Delves Into His Dementia, Life After Diagnosis

Toto's Bobby Kimball's quality of life after his frontotemporal dementia diagnosis is the subject of a forthcoming film ... documenting his journey years after his diagnosis.

John Zaika -- Bobby's longtime friend and the director of the documentary "Kite on a String: The Bobby Kimball Story" -- tells TMZ ... there were signs something was wrong when he was working with the "Africa" hitmaker more than a decade ago, indications like severe hearing loss and some "off behaviors."

The Toto singer noticed something might be wrong with his memory in 2019, so he confided in his wife, Jasmin. They sought help at UCLA's Memory Clinic and he was diagnosed with frontotemporal dementia that same year -- BTW, the same form of dementia Bruce Willis was diagnosed with in 2023.

Jasmin tells TMZ her husband learned he had aphasia at the same time as his dementia. Bruce himself was originally diagnosed with aphasia in 2022.

Bobby -- a 6-time Grammy winner -- still lives in his Los Angeles home with his wife, with the help of 2 caretakers ... one during the week and one on the weekends.

While John notes frontotemporal dementia is "hard and complicated to deal with," Bobby is still able to live a fulfilled -- albeit more subdued -- life.

He stays inside his home mostly, but he went to Malibu to film for 'Kite on a String' and frequents L.A. restaurants and parks with his wife and other trusted individuals. And get this -- he's still playing his piano!

'Kite on a String' documents Bobby's incredibly successful musical journey with Toto and as a solo artist and dives into his personal life .... including his day-to-day with dementia.

John tells TMZ there will be interviews with doctors giving insight into Bobby's diagnosis as well ... the film does not yet have a release date.