Accepted for Publication: August 16, 2010.
Author Contributions: All authors had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Sharma, Hicks, Berna, Kennard, Talbot, and Turner. Acquisition of data: Sharma and Turner. Analysis and interpretation of data: Sharma, Kennard, and Turner. Drafting of the manuscript: Sharma, Hicks, Kennard, and Turner. Critical revision of the manuscript for important intellectual content: Hicks, Berna, Kennard, Talbot, and Turner. Administrative, technical, and material support: Sharma, Berna, Kennard, and Turner. Study supervision: Berna, Kennard, Talbot, and Turner.
Financial Disclosure: None reported.
Funding/Support: This study was supported by a Rhodes Trust Scholarship (Dr Sharma) and by the Medical Research Council/Motor Neurone Disease Association Lady Edith Wolfson Fellowship (Dr Turner).