[1] Merz Pharmaceut, Frankfurt, Germany
[2] Columbia Univ Coll Phys & Surg, Dept Otolaryngol Head & Neck Surg, 630 W 168th St, New York, NY 10032 USA
[3] Icahn Sch Med Mt Sinai, Dept Neurol, New York, NY 10029 USA
[4] Med Univ Warsaw, Dept Neurol, Fac Hlth Sci, Warsaw, Poland
[5] Univ Hosp Brussels, Otorhinolaryngol, Brussels, Belgium
[6] Parkinson Klin Wolfach, Wolfach, Germany