[1] WASHINGTON UNIV, SCH MED, DIV BIOSTAT, ST LOUIS, MO 63110 USA
[2] WASHINGTON UNIV, SCH MED, DEPT NEUROL, ST LOUIS, MO 63110 USA
[3] OHIO STATE UNIV, COLL MED, DEPT NEUROL, COLUMBUS, OH 43210 USA
[4] UNIV ROCHESTER, STRONG MEM HOSP, DEPT NEUROL, ROCHESTER, NY 14642 USA
[5] WALTEM MCKENZIE CTR HLTH SCI, DEPT NEUROL, EDMONTON, NB, CANADA