1. Department of Neurology, Allegheny General Hospital, Pittsburgh, PA, USA
2. Department of Neurology, Drexel University College of Medicine, Pittsburgh, PA, USA
3. Department of Neurology, Heinrich-Heine University, Düsseldorf, Germany
4. Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD, USA
5. Montreal Neurological Institute, McGill University, Montreal, Canada