Brain Damage During New-Onset Refractory Status Epilepticus

Status epilepticus (SE) has long been linked to neuronal damage in experimental and animal studies, yet direct human evidence remains scarce. The risk of seizure-induced brain injury is central to the definition, urgency, treatment, and prognosis of SE. We studied 2,055 longitudinal MRI scans from 559 individuals, including 33 patients with new-onset refractory SE (NORSE) across multiple centres, to quantify grey matter volume changes during and after SE. We demonstrate a rapid, widespread, and irreversible decline in grey matter volume during NORSE, exceeding normal aging by 80-fold and Alzheimer’s disease by 20-fold. Fluid biomarkers confirmed marked neurodegeneration during NORSE, correlated with grey matter volume reduction, and returned to low levels after SE. Accelerated atrophy was linked to longer SE duration, poorer long-term outcome, and cryptogenic aetiology. These findings underscore the urgency of treating SE to limit brain damage and provide a framework for evaluating potentially neuroprotective interventions in humans.