1. Department of Neurology, University Hospital of Larissa, School of Medicine, University of Thessaly, Larissa, Greece;
2. Department of Neurosurgery, University Hospital of Larissa, School of Medicine, University of Thessaly, Larissa, Greece;
3. Department of Biomathematics, School of Medicine, University of Thessaly, Larissa, Greece;
4. Center for Clinical Evidence Synthesis, the Institute for Clinical Research and Health Policy Studies, Tufts Medical Center, Tufts University School of Medicine, Boston, Massachusetts, USA;
5. Department of Nephrology, University Hospital of Larissa, School of Medicine, University of Thessaly, Larissa, Greece