1. Department of Neurosurgery, Charité, Universitaetsmedizin Berlin, CVK, Berlin, Germany
2. Center for Stroke Research, Charité, Universitaetsmedizin Berlin, CCM, Berlin, Germany
3. Department of Neurology, Charité, Universitaetsmedizin Berlin, CCM, Berlin, Germany
4. Department of Neurosurgery, Technical University of Munich, Munich, Germany
5. Department of Neurosurgery, Universitaetsmedizin Goettingen, Goettingen, Germany
6. Department of Neuroradiology, Klinikum Hirslanden, Zurich, Switzerland