[1] Univ Calif San Francisco, Dept Neurol Surg, Moffitt Hosp M779, San Francisco, CA 94143 USA
[2] Helen Hayes Hosp, Ctr Neurol Recovery & Rehabil Res, W Haverstraw, NY USA
[3] Columbia Univ, Dept Pharmacol, New York, NY USA
[4] Columbia Univ, Dept Neurol, New York, NY USA