Mignano confirmed Thursday that the singer had suffered a serious medical setback. Michaels had a Transient Ischemic Attack, otherwise known as a "warning stroke."
Doctors also found a hole in his heart after running tests, which his physician said was probably unrelated to last month's brain hemorrhage.
The 47-year-old rocker-TV reality star was hospitalized after experiencing numbness on the left side of his body, particularly in his face and hands.
The Associated Press contributed to this report.
