[1] Univ Florida, Dept Neurol, Natl Parkinson Fdn,Ctr Excellence, Movement Disorders Ctr,McKnight Brain Inst, Gainesville, FL 32611 USA
[2] Univ Penn, Dept Neurol, Natl Parkinson Fdn,Ctr Excellence, Educ & Clin Ctr,NIH Udall Ctr,VA Parkinson Dis Re, Philadelphia, PA 19104 USA
[3] Oregon Hlth & Sci Univ, VA Parkinson Dis Res, Natl Parkinson Fdn,Ctr Excellence, Educ & Clin Ctr, Portland Va, OR USA
[4] Dartmouth Hitchcock Med Ctr, Lebanon, NH 03766 USA
[5] Radboud Univ Nijmegen, Med Ctr, Natl Parkinson Fdn,Ctr Excellence, Donders Inst Brain Cognit & Behav,Dept Neurol, Nijmegen, Netherlands
[6] Univ Toronto, Dept Med, Div Neurol, Natl Parkinson Fdn,Ctr Excellence, Toronto, ON, Canada
[7] Northwestern Univ, Dept Neurol, Natl Parkinson Fdn,Ctr Excellence, Parkinsons Dis & Movement Disorders Ctr, Chicago, IL USA
[8] VA Greater Los Angeles Healthcare Syst, VA Parkinsons Dis Res Educ & Clin Ctr, Los Angeles, CA USA
[9] NY Univ, New York Univ Pk, Natl Parkinson Fdn,Ctr Excellence, Dept Neurol, New York, NY USA
[10] NY Univ, Movement Disorder Ctr, New York, NY USA
[11] Struthers Parkinsons Ctr, Natl Parkinson Fdn,Ctr Excellence, Minneapolis, MN USA
[12] Menninger Dept Psychiat & Behav Sci, Houston, TX USA
[13] Tel Aviv Univ, Sackler Sch Med, Tel Aviv Sourasky Med Ctr, Movement Disorders Unit,Natl Parkinson Fdn,Ctr Ex, IL-69978 Tel Aviv, Israel
[14] Natl Parkinson Fdn, Miami, FL USA