Doctors planned to perform brain function tests Wednesday on rapper DMX, who is in a coma after a heart attack reportedly brought on by a drug overdose. The star has struggled with addiction throughout his life. DMX, who is 50 and whose legal name is Earl Simmons, is on life support, and the tests will determine the next steps in his treatments. His manager Steve Rifkind said in a statement late Tuesday, “He will undergo further tests on his brain function and his family will determine what’s best from there. We appreciate your prayers and support.” Supporters gathered at the New York hospital where he is being treated to say their well-wishes.