1. Second Department of Neurology, “Attikon” University Hospital, National and Kapodistrian University of Athens, Athens, Greece
2. Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
3. Second Department of Internal Medicine, Research Institute and Diabetes Center, Athens University Medical School, “Attikon” University Hospital, Haidari, Greece
4. Cognitive and Movement Disorders Unit and Unit of Neurochemistry and Biological Markers, First Department of Neurology, “Eginition” University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
5. Department of Neurology, University of Tennessee Health Science Center, Memphis, TN, USA