Doctors at the French hospital where Michael Schumacher remains in a critical condition say they can't predict his chances of recovery. The retired seven-time Formula One world champion suffered a serious head injury in a ski-ing accident on Sunday. (Reuters)

Michael Schumacher, the legendary former Formula One driver, remained in a medically-induced coma Monday morning with the prognosis for recovery from a brain injury he suffered in a skiing accident Sunday uncertain.

“Unfortunately, he had some lesions to his brain when he came in, he had some diffuse injuries to his brain, but we can’t really say what the outcome will be,” Jean-Francois Payen, an anesthesiologist who is leading Schumacher’s medical team, said in a news conference at the Grenoble University Hospital Center in France. “He’s in a critical situation and we can say he’s fighting for his life. We judge him to be in a very serious condition.”

Payen said that doctors are working “hour by hour,” but added that “it’s too early to say what’s going to happen, and to give a prognosis.”

Schumacher, whose 45th birthday is Friday, was injured Sunday when he fell while skiing with his 14-year-old son, Mick, at Meribel in the French Alps and struck his head on a rock. He was taken to a nearby hospital by helicopter, then transferred to Grenoble. Schumacher, who was wearing a helmet when he fell, was conscious when the first emergency workers arrived on the scene, but was “agitated” and in shock, according to Payen. Schumacher arrived at Grenoble about 90 minutes after his fall and “we had to operate urgently to relieve the pressure on his brain,” Payen said.

“Someone who had suffered this accident without a helmet would not have made it this far,” Payen said. As is commonly the case with traumatic brain injuries, Schumacher is in a medically induced coma to prevent further damage that can occur when a patient is conscious.

Schumacher, a seven-time world champion and the most successful driver in F1 history with 91 victories, retired from racing for the second time in October 2012. He has had numerous injuries over the years, breaking his leg in a crash at Silverstone in 1999 and suffering neck and spine injuries in a 2009 motorcycle accident. A native of Germany, he retired from racing in 2006, then returned in 2010.

“Like millions of Germans, the chancellor and members of the government were extremely dismayed when they heard about Michael Schumacher’s serious skiing accident,” German Chancellor Angela Merkel’s spokesman, Steffen Seibert, said (via the Associated Press) in Berlin.

Felipe Massa, Schumacher’s former teammate with Ferrari, wrote on Instagram: “I am praying for you my brother!! I hope you have a quick recovery!! God bless you Michael.”