1. Department of Neurology, University of Kansas Medical Center, Kansas City, KS, USA
2. Department of Neurology, Ann Arbor Veterans Affairs Medical Center, University of Michigan, Ann Arbor, MI, USA
3. Department of Neurology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
4. College of Physicians and Surgeons, Columbia University, New York, NY, USA
5. Department of Neurology, University of California at San Francisco, San Francisco, CA, USA
6. Nuffield Department of Neurosciences, University of Oxford, Oxford, UK
7. Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA