From epidemiological studies, we know that SAH survivors are at higher risk for dementia compared with the general population.13 On a molecular basis, axonal injury may cause up-regulation of kinases promoting post-translational tau modifications and therefore may prime neurons for neurodegeneration.45 A prospective multi-centre cohort study, namely the DISCOVERY trial,46 is currently underway investigating long-term cognitive outcomes after ischaemic and haemorrhagic stroke including SAH patients. The gene discussed is MAPT; the disease is hemorrhagic stroke.