Formula One: Agonising wait for Schumachers and Bianchis

And the race track accident suffered by 25-year-old Jules Bianchi three months ago has only added to anxiety surrounding the motor racing circus.

Retired seven time world driving champion Schumacher made global headlines again on December 29 last year with a ski accident that caused critical brain injuries and left him in a coma lasting several months.

Schumacher, now 45, hit a rock while skiing off piste in the French Alps resort of Meribel.

From a hospital in Grenoble, Schumacher was moved to a Swiss clinic in June once safely out of an artificial coma. He was moved back to his home at Gland on the shores of Lake Leman in Switzerland in September.

His wife, Corinna, has imposed a news blackout on the star's condition.

Family spokeswoman, Sabine Kehm, says only that Schumacher faces a "long" struggle.

Jean-Francois Payen, a French doctor who has treated Schumacher, said there has been "progress" but that it would take years to see a real improvement.

Most experts are talking about a three year recovery.

The family said in a statement posted on the Schumacher website last month that they remain "optimistic". Kehm told the German daily Bild on Sunday that there is "a little calm" around Schumacher now that the worst months are over.

Schumacher's army of fans keep the faith on social media. But the German racing ace has missed seeing his 15-year-old son Mick come second in the world junior kart championships in October.

He is also probably unaware of the terrible fate of Jules Bianchi, who in October crashed off the rain drenched Suzuka circuit during the Japanese Grand Prix and smashed into a recovery truck.

The 25-year-old Frenchman also suffered life-threatening brain injuries, probably unaware that an International Automobile Federation inquiry found that he was driving too fast when he crashed.

Bianchi's condition now is also a closely guarded family secret. But he was well enough to be brought to a hospital near the family in Nice. Like the Schumachers, the Bianchis face an agonising wait.

"A prognosis could be made six months after the accident," said Denis Safran, head of the intensive care and anaesthetic at the Georges Pompidou Hospital in Paris.

"But improvements can of course still be made after this date," he added.