A post-operative scan had also shown "diffuse haemorrhagic lesions" on both sides of Schumacher's brain but the doctors were unable to comment on a prognosis.
He is under the care of physician Gérard Saillant who is a brain and spinal injury expert and a personal friend of Schumacher.
Saillant had previously overseen Schumacher's medical care when the driver broke his leg in the 1999 British Grand Prix.