The intervention group receives an early and intensive mobilization programme with head-up tilt, during their stay in the intensive care unit and throughout the early stages of rehabilitation. Mobilization will be conducted using a tilt-table with integrated stepping (The ERIGO® from HOCOMA company in Switzerland). The programme will be conducted as a supplement to the patient's usual care.The tilt-table intervention is applied five times per week for a maximum of four weeks during the stay in the neurointensive care unit. Each session consists of 20 min. mobilization. Within each session the patient will be moved to the tilt-table and secured with straps and harness. The patient is then mobilized step wise to 30°, 50° and 70° head-up tilt in one min. intervals while blood pressure, heart rate, and respiratory rate are closely monitored. Cerebral perfusion pressure and intracranial pressure are monitored if relevant. If at any time the predetermined safety limits for blood pressure, cerebral perfusion pressure, intracranial pressure or heart rate are violated, the patient is lowered to 0° tilt (supine position). This procedure is continued until the patient has been tilted upright for a maximum of 20 min. or until a total duration of 40 min. for the head-up tilt procedure has been reached.