Secondary endpoints: (1) dementia (DSMIV and NINDS-AIREN criteria ;National Institute of Neurological Disorders and Stroke and the Association Internationale pour la Recherche et l'Enseignement en Neurosciences ); (2) screening tests (MiniMental Status Examination, Montreal Cognitive Assessment);(3) MRI abnormalities (cerebral atrophy, white matter abnormalities, stroke type, stroke volume and location) using 3D T1-weighted (axial bicommissural plane), T2-weighted (coronal plan), FLAIR, gradient-echo, diffusion-weighted (with calculation of the apparent diffusion coefficient) performed at 6 months post-stroke at the same time than the cognitive assessment; (4) disability in activities of daily living (Rankin scale, Barthel index, Instrumental Activities of Daily Living).