[1] Natl Multiple Sclerosis Ctr, Vanheylenstr 16, B-1820 Melsbroek, Belgium
[2] Vrije Univ Brussel, Ctr Neurosci, Brussels, Belgium
[3] Vrije Univ Brussel, Lab Expt Surg, UZ Brussel, Brussels, Belgium
[4] Vrije Univ Brussel, Ctr Outcomes Res, UZ Brussel, Brussels, Belgium
[5] Univ Groningen, Univ Med Ctr Groningen, Dept Neurol, Groningen, Netherlands