[1] Cleveland Clin, Neurol Inst, Dept Neurol, Cleveland, OH USA
[2] Mayo Clin, Coll Med, Ctr Multiple Sclerosis & Autoimmune Neurol, Dept Neurol, Rochester, MN USA
[3] Cleveland Clin Fdn, Mellen Ctr Multiple Sclerosis, Cleveland, OH USA
[4] Univ Montreal, Ctr Hosp Univ Montreal, Fac Med, Dept Neurosci,Dept Neurol, Montreal, PQ, Canada