[1] Heidelberg Univ, Dept Neurol, D-69120 Heidelberg, Germany
[2] Heidelberg Univ, Dept Neuroradiol, D-69120 Heidelberg, Germany
[3] Heidelberg Univ, Inst Med Biometry & Informat, D-69120 Heidelberg, Germany
[4] Heidelberg Univ, Dept Internal Med 1, D-69120 Heidelberg, Germany
[5] Univ London Imperial Coll Sci Technol & Med, Dept Stroke Med, London, England