[1] Brigham & Womens Hosp, Dept Neurol, 75 Francis St, Boston, MA 02115 USA
[2] Massachusetts Gen Hosp, Dept Radiol, Boston, MA USA
[3] Massachusetts Gen Hosp, Dept Neurol, Boston, MA 02114 USA
[4] Massachusetts Gen Hosp, Dept Pathol, Boston, MA 02114 USA
[5] Harvard Med Sch, Dept Neurol, Boston, MA 02115 USA
[6] Harvard Med Sch, Dept Radiol, Boston, MA 02115 USA
[7] Harvard Med Sch, Dept Pathol, Boston, MA 02115 USA