[1] Oregon Hlth Sci Univ, Dept Neurol, Portland, OR 97201 USA
[2] Oregon Hlth Sci Univ, Sch Nursing, Portland, OR 97201 USA
[3] Rush Presbyterian St Lukes Med Ctr, Chicago, IL 60612 USA
[4] Brown Univ, Providence, RI 02912 USA
[5] Univ Virginia, Charlottesville, VA USA
[6] Massachusetts Gen Hosp, Boston, MA 02114 USA
[7] Univ Rochester, Rochester, NY USA
[8] McGill Univ, Montreal, PQ, Canada
[9] Univ Kansas, Lawrence, KS 66045 USA
[10] Univ Calgary, Med Clin, Calgary, AB, Canada
[11] Univ Iowa, Iowa City, IA USA
[12] Toronto Western Hosp, Toronto, ON M5T 2S8, Canada
[13] Univ Nebraska, Med Ctr, Omaha, NE USA
[14] Ottawa Civic Hosp, Ottawa, ON K1Y 4E9, Canada
[15] Univ Saskatchewan, Saskatoon, SK, Canada
[16] St Lukes Hosp, Denver, CO USA
[17] Calif Parkinsons Fdn, Sunnyvale, CA USA
[18] Sinai Hosp, Detroit, MI 48235 USA
[19] Univ S Florida, Tampa, FL USA
[20] Univ Calif San Diego, San Diego, CA 92103 USA
[21] Univ Miami, Miami, FL 33152 USA
[22] Columbia Univ, New York, NY USA
[23] Univ Penn, Philadelphia, PA 19104 USA
[24] Ohio State Univ, Columbus, OH 43210 USA