1. Wolfson Centre for Prevention of Stroke and Dementia, Nuffield Department of Clinical Neurosciences, University of Oxford, United Kingdom (I.J.M., P.M.R.).
2. Neurovascular Clinical Science Unit, Stroke Service and Department of Neurology, Mater University Hospital, Dublin, Ireland (P.J.K.).
3. Department of Neurology, Medical University of South Carolina, Charleston (T.N.T.).