1. Department of NeurologySafarik UniversityKosice Slovakia
2. Department of NeurologyUniversity Hospital of L. PasteurKosice Slovakia
3. Rush University Medical Center, Department of Neurological Sciences, Section of Parkinson Disease and Movement DisordersChicago Illinois USA
4. Sobell Department of Motor Neuroscience & Movement Disorders and the National Hospital for Neurology & NeurosurgeryLondon UK
5. Morton and Gloria Shulman Movement Disorders Centre and the Edmond J. Safra Program in Parkinson's DiseaseToronto Western HospitalToronto Ontario Canada
6. Applied Neuroscience Research Group, Central European Institute of Technology, CEITECMasaryk UniversityBrno Czech Republic
7. Department of PsychologyUniversity of AmsterdamAmsterdam The Netherlands
8. Department of PsychiatryLeiden University Medical Centre, Leiden, and Centre of Mental Health Care DelflandDelft Netherlands
9. Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania and Parkinson's Disease and Mental Health Research, Education and Clinical Centers (PADRECC and MIRECC)Philadelphia Veterans Affairs Medical CenterPhiladelphia Pennsylvania USA
10. National Centre of Epidemiology and CIBERNEDCarlos III Institute of HealthMadrid Spain