Michael Schumacher leaving coma

— -- LONDON -- Michael Schumacher's doctors have started trying to wake up the former Formula Champion from the medically induced coma he's been in since a skiing accident last month, his manager said Thursday.

The 45-year-old Schumacher suffered serious head injuries when he fell and hit the right side of his head on a rock in the French resort of Meribel on Dec. 29. The seven-time F1 champion has been in an induced coma in Grenoble University Hospital since then, although his condition stabilized following surgery after initially being described as critical.

"Michael's sedation is being reduced in order to allow the start of the waking up process which may take a long time," Schumacher's manager, Sabine Kehm, said in a statement. Schumacher was being kept artificially sedated and his body temperature was lowered to between 34 and 35 degrees Celsius (93.2 and 95 degrees Fahrenheit), to reduce swelling in the brain, reduce its energy consumption and allow it to rest.

Kehm said she was only providing an update now on Schumacher's condition to clarify media leaks, and that no further details would be provided. French newspaper l'Equipe first reported on Wednesday that doctors had started trying to wake up Schumacher.

Experts said it was a good sign that Schumacher's doctors were trying to bring him out of the coma and that the first 24 hours would be critical.

"It means they have probably seen the pressure in his skull reduced," said Dr. Clemens Pahl, a brain trauma expert at King's College Hospital in London.

Pahl warned that if Schumacher hasn't recovered enough to wake up on his own, doctors might need to put him back in the coma.

"It could be that swelling in his brain hasn't come to an end yet so they might need to increase the medications again," he said. Pahl said that wasn't uncommon in patients with brain injuries and that sometimes it took several attempts to bring someone out of an induced coma.

Brain experts said it will be fundamental to determine whether Schumacher was aware of his surroundings and could respond to basic commands from doctors, like raising his hand.

"This is a test to see what his function is like," said Dr. Anthony Strong, an emeritus chair in neurosurgery at King's College London. He said that once the sedatives wear off, Schumacher's doctors would see if he can breathe on his own and if he responds to mild pain stimulus, like gentle pressing on his eyebrows.

"Doctors will want to see if he can say 'hello,' if he probe his recollection of events and to see if he can recognize family members and remember his own identity," Strong said. If Schumacher doesn't respond to their voice, they will also look to see if he tries to pull out any of the tubes in him or rip the dressing off his wounds -- which would be a sign that he is aware of where he is.

Still, experts said it would likely be months before Schumacher's prognosis becomes clear -- and that lasting brain damage was a possibility.

"If he pulls through, he may not be the man he was," said Dr. Tipu Aziz, head of neurosurgery at Oxford University. "Given the length of time he's been in (intensive care), he has clearly had a very severe head injury," he said. "It's too early to know how intact he will be, but I would guess there is going to be some kind of lasting damage."

Schumacher earned universal acclaim for his uncommon and sometimes ruthless driving talent, which led to a record 91 race wins. He retired from Formula One in 2012 after garnering an unmatched seven world titles. His accident happened on a family vacation in the Alps as Schumacher was skiing with his 14-year-old son.