1. Duke Neurological Disorders Clinic Duke University Medical Center Durham North Carolina USA
2. Faculty of Medicine and University Clinical Center of Serbia, Neurology Clinic University of Belgrade Belgrade Serbia
3. Neurology Clinic University Clinical Center of Serbia Belgrade Serbia
4. Neurology Clinic University Clinical Center of Kragujevac Kragujevac Serbia
5. Neurology Clinic University Clinical Center of Nis Nis Serbia
6. Department of Neurology University of Minnesota Minneapolis Minnesota USA