[1] Columbia Univ, Dept Neurol, 650 168th St,Room 305, New York, NY 10032 USA
[2] New York Presbyterian Hosp, New York, NY USA
[3] Columbia Univ, Irving Med Ctr, Initiat Columbia Ataxia & Tremor, New York, NY USA
[4] Columbia Univ, Teachers Coll, New York, NY USA
[5] Univ Irving Med Ctr, New York, NY USA
[6] SUNY Downstate, Dept Neurol, Brooklyn, NY USA