Accepted for Publication: January 18, 2012.
Published Online: April 9, 2012. doi:10.1001/archneurol.2012.70
Author Contributions:Study concept and design: Wetzel and Baron. Acquisition of data: Gitchel and Baron. Analysis and interpretation of data: Gitchel, Wetzel, and Baron. Drafting of the manuscript: Gitchel. Critical revision of the manuscript for important intellectual content: Gitchel, Wetzel, and Baron. Statistical analysis: Gitchel and Wetzel. Obtained funding: Wetzel and Baron. Administrative, technical, and material support: Gitchel. Study supervision: Wetzel and Baron.
Financial Disclosure: None reported.
Funding/Support: This research was supported by the Department of Veterans Affairs.
Additional Contributions: We thank Abu Qutubuddin, MD (physiatrist, Southeast Parkinson's Disease Research, Education, and Clinical Center, Hunter Holmes McGuire Veterans Affairs Medical Center), and Peggy Roberge, RN (clinical nurse coordinator, Southeast Parkinson's Disease Research, Education, and Clinical Center), for their assistance in recruiting study subjects.