[1] Univ Toledo, Coll Med, Dept Neurol, Toledo, OH 43606 USA
[2] Ctr Dis Control & Prevent, Carter Consulting Inc, Atlanta, GA USA
[3] Lankenau Hosp, Wynnewood, PA USA
[4] Kaiser Permanente, San Diego, CA USA
[5] Ctr Dis Control & Prevent, CDC, Natl Ctr Chron Dis Prevent & Hlth Promot, Atlanta, GA USA