1. Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA
2. Olmsted Medical Center, Rochester, MN, USA
3. Department of Neurology, Mayo Clinic, Rochester, MN, USA
4. Department of Neurology, University of Pittsburgh Medical Center, Pittsburg, PA, USA
5. Department of Neuropsychiatry, Minia University, Minia, Egypt
6. Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905-0002, USA