Inside Celine Dion's battle with illness that turns people into 'human statues': Widowed singer, 55, vanished from the spotlight after stiff-person syndrome diagnosis - but Grammy's appearance marks step in her return to public life

The Montreal-born singer, 55, has largely kept a low profile since announcing her neurological disorder in 2022 but delighted fans when she made a surprise appearance onstage at the Grammy Awards last night.