1. Department of Neurology, School of Medicine, University of Ioannina, Ioannina, Greece
2. 1st Division of Internal Medicine, School of Medicine, University of Ioannina, Ioannina, Greece
3. Second Department of Neurology, Medical School, University of Athens, Athens, Greece
4. International Clinical Research Center, Department of Neurology, St. Anne's University Hospital in Brno, Brno, Czech Republic