Inclusion Criteria:  Admitted to the Rothschild Foundation within the first 24 hours of an acute neurological symptomatology related to : ischemic stroke eligible for a mechanical thrombectomy procedure subarachnoid haemorrhage due to aneurysmal rupture: patient with at least a modified Fisher scale 3 or 4 (Appendix 4) and a World Federation of Neurological Surgeons (WFNS) score of 2 or more intra-parenchymal haematoma with a Glasgow Coma Scale (GCS) strictly below 15. tissue-based transient ischaemic attack - no lesion found on imaging - with ABCD2≥ 2 (control group). Hospitalisation to the Fondation Adolphe de Rothschild Hospital at least 72 hours is planned  Exclusion Criteria:  Pre-existing functional and/or cognitive disability Patient under legal protection Pregnant or breastfeeding woman