[1] Univ Pittsburgh, Sch Med, Dept Neurol, S514 BST,200 Lothrop St, Pittsburgh, PA 15213 USA
[2] Vet Affairs Pittsburgh Healthcare Syst, Geriatr Res Educ & Clin Ctr, Pittsburgh, PA 15261 USA
[3] Brown Univ, Warren Alpert Med Sch, 222 Richmond St, Providence, RI 02903 USA
[4] Univ Calif Riverside, Sch Med, Div Biomed Sci, 1212 Webber Hall, 900 Univ Ave, Riverside, CA 92521 USA