1. Department of Neurology Johns Hopkins University School of Medicine Baltimore Maryland 21205 USA
2. Institute of Organic Chemistry and Macromolecular Chemistry Friedrich Schiller University Jena Jena 07743 Germany
3. Centre for Biomolecular Magnetic Resonance Goethe‐University Frankfurt 60438 Germany
4. Departments of Otolaryngology – Head & Neck Surgery & Pediatrics, Eastern Virginia Medical School, and Department of Pediatric Otolaryngology Children's Hospital of the King's Daughters Norfolk Virginia 23508 USA
5. Department of Neurosurgery Virginia Commonwealth University Health System Richmond Virginia 23298 USA
6. Department of Neurology Virginia Commonwealth University Health System Richmond Virginia 23298 USA
7. The Solomon H. Snyder Department of Neuroscience Johns Hopkins University School of Medicine Baltimore Maryland 21205 USA