1. Department of Neuroscience, Neurosurgery, Uppsala University, Uppsala University Hospital, Uppsala;
2. Department of Clinical Sciences Lund, Neurosurgery, Lund University, Skane University Hospital, Lund;
3. Department of Neuroscience, Karolinska Institutet;
4. Department of Medicine and Clinical Neuroscience, Neurosurgery, Karolinska Institutet, Karolinska University Hospital, Stockholm;
5. Department of Neurosurgery, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
6. Department of Clinical Neuroscience, Neurosurgery, University of Gothenburg, Sahlgrenska Academy, Sahlgrenska University Hospital, Gothenburg;
7. Department of Clinical and Experimental Medicine, Neurosurgery, Linköping University, Linköping University Hospital, Linköping;
8. Department of Clinical Neuroscience, Neurosurgery, Umeå University, Umeå University Hospital, Umeå, Sweden; and