Michael bowled out of turn multiple times, which immediately concerned his family. “That was when we were like, ‘Something’s wrong with his brain,'” Taryn said.
Michael Bolton’s Very Rare Diagnosis Revealed — What We Know

Michael Bolton attends the Build Series at Build Studio in New York City on February 8, 2017 | Source: Getty Images
Earlier that evening, he had fallen from a chair — something uncharacteristic for the athletic and sober performer — and later developed a severe headache.
Despite remaining active with concerts, a new album, and a movie cameo, Michael had also experienced nausea and balance issues at a charity event weeks earlier. His daughters initially attributed the symptoms to stress and exhaustion.
When he underwent an MRI the following Monday, doctors found a brain tumor. Surgeons removed it entirely, and a week later, pathology confirmed it was glioblastoma. Dr. Ingo Mellinghoff of Memorial Sloan Kettering explained that symptoms such