CSL Behring, King of Prussia, PA, USA. Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA. Ellen and Martin Prosserman Centre for Neuromuscular Diseases, Division of Neurology, Department of Medicine, University Health Network, University of Toronto, Toronto, Canada. Institute for Research and Medical Consultations, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia. Department of Neurology, UKD and Center for Neurology and Neuropsychiatry, LVR Klinikum, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany. Brain and Mind Centre, University of Sydney, Sydney, Australia. Medical University of Vienna, Vienna, Austria. Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan. Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, USA. Department of Neurology, Maastricht University Medical Center, Maastricht, the Netherlands. Curaçao Medical Center, Willemstad, Curaçao. CSL Behring, Marburg. Princeton, NJ, USA. University of Basel, Basel, Switzerland. Department of Neurology, Amsterdam University Medical Centres, University of Amsterdam, Amsterdam and Spaarne Gasthuis, Haarlem, the Netherlands.