Clinical examination: Patients will be examined clinically by a neurologist at the screening visit, at the randomization visit, 14 +/- 7 days after randomization, at 3 months and at 6 months after randomization. At each visit, clinical outcome events will be assessed, focal neurological deficit measured using the National Institutes of Health (NIH) Stroke Scale,12 and functional level of independence using the modified Rankin Scale13. Clinical outcome events will be independently adjudicated in the coordinating center Basel, blinded to the type of treatment.