[1] Harvard Med Sch, Brigham & Womens Hosp, Dept Neurol, Boston, MA USA
[2] Harvard Med Sch, Brigham & Womens Hosp, Dept Med, Boston, MA USA
[3] Harvard Med Sch, Brigham & Womens Hosp, Dept Radiol, Boston, MA USA
[4] Harvard Med Sch, Brigham & Womens Hosp, Lab Neuroimaging Res, Boston, MA USA
[5] Harvard Med Sch, Brigham & Womens Hosp, Partners MS Ctr, Boston, MA USA