1. Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
2. Department of Ophthalmology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
3. Department of Otorhinolaryngology, Head and Neck Surgery, lnselspital, Bern University Hospital, University of Bern, Bern, Switzerland
4. Department of Neurology, Ophthalmology, Otolaryngology-Head and Neck Surgery, Johns Hopkins Hospital, Baltimore, USA, MD