1. Department of Neurology Mayo Clinic Rochester Minnesota USA
2. Department of Neurology University of Toronto Toronto Ontario Canada
3. Department of Neurology Columbia University New York New York USA
4. Department of Neurology University Medical Center Utrecht Utrecht the Netherlands
5. Chicago Illinois USA
6. Department of Pediatrics University of Colorado Aurora Colorado USA
7. Boston Massachusetts USA
8. Department of Neurology University of Chicago Chicago Illinois USA
9. Istituto di Ricovero e Cura a Carattere Scientifico Istituto Giannina Gaslini and Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health University of Genoa Genoa Italy
10. Department of Neurology University of California, Los Angeles Los Angeles California USA
11. Department of Neurology Massachusetts General Hospital Boston Massachusetts USA
12. Department of Neurology University of Virginia Charlottesville Virginia USA