[1] Charite Univ Med Berlin, Ctr Stroke Res Berlin, Campus Charite Mitte, Charitepl 1, D-10117 Berlin, Germany
[2] Charite Univ Med Berlin, Dept Neurol, D-10117 Berlin, Germany
[3] Charite Univ Med Berlin, Dept Expt Neurol, D-10117 Berlin, Germany
[4] Charite Univ Med Berlin, Dept Neurosurg, D-10117 Berlin, Germany
[5] Charite Univ Med Berlin, Dept Anesthesiol, D-10117 Berlin, Germany
[6] Kings Coll London, Dept Clin Neurosci, London, England
[7] Univ Cincinnati, Dept Neurosurg, Cincinnati, OH USA