1. Department of Neurology, Mayo Clinic College of Medicine and Science, Rochester, Minnesota
2. Department of Medical, Surgical and Experimental Sciences, University of Sassari, Sassari, Italy
3. Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine and Science, Rochester, Minnesota
4. Department of Ophthalmology, Mayo Clinic College of Medicine and Science, Rochester, Minnesota
5. Department of Health Sciences Research, Mayo Clinic College of Medicine and Science, Rochester, Minnesota
6. Department of Clinical Neurological Sciences, London Health Sciences Centre, Western University, London, Ontario, Canada
7. Department of Neurology, Mayo Clinic, Jacksonville, Florida