[1] Univ Washington, Harborview Med Ctr, Dept Neurol & Med, Sch Med, Seattle, WA 98104 USA
[2] Harvard Univ, Sch Publ Hlth, Ctr Biostat AIDS Res, Boston, MA 02115 USA
[3] Rush Med Coll, Cook Cty Hosp, CORE Ctr, Chicago, IL 60612 USA
[4] Northwestern Univ, Sch Med, Dept Neurol, Chicago, IL 60611 USA
[5] Washington Univ, Sch Med, Dept Neurol, St Louis, MO 63110 USA
[6] Univ Miami, Sch Med, Dept Radiol, Miami, FL USA
[7] Univ Washington, Fred Hutchinson Canc Res Ctr, Program Infect Dis, Div Virol, Seattle, WA 98195 USA
[8] Social & Sci Syst Inc, Adult AIDS Clin Trials Grp, Bethesda, MD 20814 USA