[1] Charite, Neurol Klin & Poliklin, D-13353 Berlin, Germany
[2] Charite, Ctr Stroke Res Berlin, D-13353 Berlin, Germany
[3] Massachusetts Gen Hosp, Dept Radiol, Neurovasc Res Lab, Charlestown, MA 02129 USA
[4] Harvard Univ, Sch Med, Charlestown, MA 02129 USA