From the *Department of Neurology, Mayo Clinic, Rochester, MN; †Department of biomedical Statistics, May Clinic, Rochester, MN;
‡Department of Neurology, Boston University, Boston, MA, §Department of Neurology, National University of Singapore, Singapore, Singapore; ||Department of Neurology, Cleveland Clinic, Cleveland, OH; ¶Department of Radiology, Mayo Clinic, Rochester, MN