1. Department of Neurology Kiel University Kiel Germany
2. Department of Neuroradiology Kiel University Kiel Germany
3. Movement Disorders Section Department of Neurology Hannover Medical School Hannover Germany
4. Department of Neurology University of Düsseldorf Düsseldorf Germany
5. Human Motor Control Section Medical Neurology Branch National Institute of Neurological Disorders and Stroke National Institutes of Health Bethesda Maryland