Inclusion Criteria:  Symptomatic severe aortic stenosis (>60 years old) being scheduled for either transfemoral TAVR or isolated SAVR  Exclusion Criteria:  Patients who have been diagnosed with brain cancer, brain haemorrhage, brain abscess, aneurysm, cerebral palsy, encephalitis, nervous system infection, head or neurological injury, or trauma, stroke Contraindications for a magnetic resonance imaging (MRI) scan (i.e. metallic implants, claustrophobia, MR-incompatible pacemakers or prosthetic heart valves) Unremovable dental prostheses that are deemed to affect MRI quality Severe coronary artery disease that is unrevascularized Prior stroke within the last 12 months Expected non-compliance concerning follow-up examinations Have participated in other clinical trials