A study led by a pair of Arizona State University speech scientists revealed legendary boxer Muhammad Ali, who passed away in Scottsdale earlier this year, showed signs of slowed and slurred speech years before he was diagnosed with Parkinson's disease, ESPN reported Wednesday.
Ali was diagnosed with Parkinson's, a disorder of the nervous system that affects the body's motor skills, in 1984 when he was 42 years old. But a study conducted by ASU's Visar Berisha and Julie Liss showed Ali's speech slowed by 26 percent from the time he was 26 years old to the time he was 39.
"He was slurring his words by 1978 -- three years before his retirement from boxing and six years before his Parkinson's diagnosis," ESPN's William Weinbaum wrote. "The study asserts that such changes have been shown to be among the first symptoms for many who develop the condition."
The complete study is set to be released at Interspeech 2017, a conference that began in Stockholm, Sweden on Sunday and will conclude Thursday. ESPN obtained an advanced copy of the study.
Ali passed away in June 2016 at the age of 74. He had lived in Arizona for over a decade, deciding that the dry, hot climate was best for his health.
Berisha and Liss conducted a similar study among NFL players and released their findings in May. According to a New York Times story, the authors found "a steeper decline in vocabulary size and other verbal skills in 10 players who spoke at news conferences over an eight-year period, compared with 18 coaches and executives who had never played professional football and who also spoke at news conferences during the same period."
Berisha and Liss are planning to conduct a larger speech study among ASU football, hockey and soccer players, the New York Times reported.