[1] Univ Western Ontario, RRI, Stroke Prevent & Atherosclerosis Res Ctr, London, ON, Canada
[2] Univ Western Ontario, Dept Epidemiol & Biostat, London, ON, Canada
[3] Univ Florida, Dept Neurol, Jacksonville, FL USA
[4] Henry Ford Hosp, Dept Neurol, Detroit, MI 48202 USA
[5] Wellington Hosp, Dept Neurol, Wellington, New Zealand
[6] London Hlth Sci Ctr, London, ON, Canada
[7] Mayo Clin, Dept Neurol, Scottsdale, AZ USA
[8] London Hlth Sci Ctr, London, ON, Canada