1. Department of Neurology; University of Rostock; Rostock Germany
2. New York Center for Voice and Swallowing Disorders; St Luke's/Roosevelt Hospital Center; Department of Otolaryngology; Columbia University College of Physicians and Surgeons; New York NY USA
3. Institute for Diagnostic and Interventional Radiology; University of Rostock; Rostock Germany
4. Movement Disorders Section; Department of Neurology; Hannover Medical School; Hannover Germany