1. Rudolf Magnus Institute of Neuroscience, Department of Oto-Rhino-Laryngology, Department of Pharmacology and Anatomy, and Department of Physical Medicine and Rehabilitation, Utrecht, The Netherlands.
2. Department of Psychiatry and Neuropsychology, Division Neuroscience, University of Maastricht, and Department of Anesthesiology, Academic Hospital Maastricht, Maastricht, The Netherlands.
3. Department of Anesthesiology, Academic Hospital Maastricht, Maastricht, The Netherlands.