[1] Mayo Clin, Dept Neurol, Rochester, MN USA
[2] Harvard Univ, Brigham & Womens Hosp, Dept Neurol, Sch Med, Boston, MA 02115 USA
[3] Johns Hopkins Univ Hosp, Dept Neurol, Baltimore, MD 21287 USA
[4] NINDS, Sect Infect Nervous Syst, NIH, Bethesda, MD 20892 USA
[5] Harvard Univ, Massachusetts Gen Hosp, Sch Med, Dept Pathol, Boston, MA USA
[6] Harvard Univ, Massachusetts Gen Hosp, Sch Med, Dept Neurol, Boston, MA USA