One of the greatest boxers of all time, Muhammad Ali also suffered from early onset Parkinson's disease. Some specialists even say that Ali could have suffered the symptoms way before he was diagnosed with the disease. The boxer retired from boxing in 1981, when he first started to cope with shaky hands and issues with mobility. After he was diagnosed, he, Jimmy Walker, and Dr. Abraham Lieberman founded the Muhammad Ali Parkinson Center, where patients can go to as a resource for Parkinson's disease and other movement disease. 

Muhammad Ali was also a part of the Celebrity Fight Night as a featured guest. His daugher, Rasheda Ali, also wrote a children's book about Parkinson's disease entitled, I'll Hold Your Hand So You Won't Fall: A Child's Guide to Parkinson's Disease. 

Muhammad Ali passed away in June 2016.

Photo source: Muhammed Ali vs Trevor Berbick by Staf De Prince