[1] Univ Colorado, Dept Neurol, Sch Med, 12700 E 19th Ave,Campus Mailstop B-182, Aurora, CO 80045 USA
[2] Univ Colorado, Dept Med, Sch Med, Aurora, CO 80045 USA
[3] Univ Colorado, Dept Immunol Microbiol, Sch Med, Aurora, CO 80045 USA
[4] Indiana Univ Sch Med, Dept Neurol, Indianapolis, IN 46202 USA