[1] JOHNS HOPKINS UNIV, SCH MED, DEPT NEUROL, BALTIMORE, MD 21205 USA
[2] JOHNS HOPKINS UNIV, SCH MED, DEPT NEUROSCI, BALTIMORE, MD 21205 USA
[3] MASSACHUSETTS GEN HOSP, DEPT NEUROL, BOSTON, MA 02114 USA
[4] MASSACHUSETTS GEN HOSP, DEPT NEUROSURG, BOSTON, MA 02114 USA
[5] HARVARD UNIV, SCH MED, BOSTON, MA 02115 USA