Miller, 58, has appeared on TV's "Curb Your Enthusiasm" and "Seinfeld." He also frequently has roles in director Garry Marshall's films, such as "Pretty Woman," "The Princess Diaries," "Runaway Bride," "Valentine's Day" and "New Year's Eve."
People.com said Miller lost his footing, fell and hit his head on the pavement after finishing a podcast with comedian Adam Carolla last spring. He slipped into a coma and was put on life support at UCLA Medical Center for a month.
"He was hovering between life and death," his representative Michael Hansen told People.com.
"It's a miracle he woke up. ... He's lucky to be alive," Hansen said. "He had to work on some issues regarding brain connectivity."
"I'm very thankful to have recovered from a traumatic brain injury so quickly," Miller told People.com.