1 Department of Neurology (SN, RNH, MT-L), University of Texas Southwestern Medical Center, Dallas, Texas; University of Texas Southwestern Medical School (JD, PK), Dallas, Texas; Department of Ophthalmology (MS, RNH, MT-L), University of Texas Southwestern Medical Center, Dallas, Texas; and Department of Pathology (RNH), University of Texas Southwestern Medical Center, Dallas, Texas.