Accepted for Publication: June 26, 2013.
Published Online: November 4, 2013. doi:10.1001/jamaneurol.2013.4221.
Study concept and design: Li, Arbuthnott, Ke, Yung.
Acquisition of data: Li.
Analysis and interpretation of data: All authors.
Drafting of the manuscript: Ke, Yung.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Li, Ke, Yung.
Obtained funding: Qian, Ke, Yung.
Administrative, technical, or material support: Qian, Ke, Yung.
Study supervision: Ke, Yung.
Conflict of Interest Disclosures: None reported.
Funding/Support: This work was supported by the Hong Kong RGC Theme–based Research Scheme (grant T13-607/12R) and the National 973 Program (grant 2011CB510004).
Role of the Sponsor: The funding agencies had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Correction: This article was corrected on November 20, 2013, for an error in the Figure.