1. Department of Voice, Speech and Hearing Disorders, Center for Clinical Neurosciences University Medical Center Hamburg‐Eppendorf Hamburg Germany
2. Department of Neurology, Center for Clinical Neurosciences University Medical Center Hamburg‐Eppendorf Hamburg Germany
3. Clinic for Neurology and Neurophysiology Medical Center Augsburg Augsburg Germany
4. Institute of Medical Biometry and Epidemiology University Medical Center Hamburg‐Eppendorf Hamburg Germany