"It's been a great quarter of a century, and I had hoped to be able to finish out this year with the band, but I must now do what's best for all concerned."
The Parkinson's Foundation defines Parkinsonism as "a set of movement symptoms associated with Parkinson's disease and other disorders." Symptoms include "slow movements along with stiffness, walking and balance issues, and/or tremor."
Don Henley, a founding member of the Eagles, also announced Smith's retirement while praising the guitarist for his contributions to the band.