[1] Massachusetts Gen Hosp, Dept Neurol, Boston, MA 02114 USA
[2] Massachusetts Gen Hosp, Dept Radiol, Boston, MA 02114 USA
[3] Massachusetts Gen Hosp, Dept Pathol, Boston, MA 02114 USA
[4] Foothills Prov Gen Hosp, Dept Neurol, Calgary, AB T2N 2T9, Canada
[5] Univ Calgary, Dept Clin Neurosci, Calgary, AB, Canada
[6] Harvard Univ, Sch Med, Dept Neurol, Boston, MA 02115 USA
[7] Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA USA
[8] Harvard Univ, Sch Med, Dept Radiol, Boston, MA 02115 USA
[9] Harvard Univ, Sch Med, Dept Pathol, Boston, MA 02115 USA