US singer-songwriter Bobby Womack said he is beginning to show early symptoms of Alzheimer's disease, including trouble remembering names and song lyrics.
He added: "How can I not remember songs that I wrote? That's frustrating."
The 2009 Rock and Roll Hall of Fame inductee, whose hits include "Woman's Gotta Have It" and "If You Think You're Lonely Now," suffered a number of health problems in the past year.
Other recent health issues included prostate cancer, pneumonia and collapsed lungs.
The soul veteran in October won the best album award from the British magazine Q for his 2012 release, "The Bravest Man in the Universe," beating out much younger competition.
Womack got his start in the music business as the lead singer in the soul group The Valentinos, which he formed with his brothers, and played guitar for Sam Cooke.
He also wrote The Rolling Stones' first chart topper in the UK, 1964's "It's All Over Now."