Peri-Ictal MRI Abnormalities and Risk of Unprovoked Seizures After De Novo Status Epilepticus

Status epilepticus (SE) is a neurologic emergency with possible long-term sequelae, including the development of epilepsy. We aimed to determine whether peri-ictal MRI abnormalities (PMA) are associated with unprovoked seizures after de novo SE.

Adults without epilepsy and a first nonhypoxic SE were included from a prospective database of the Christian Doppler University Hospital, Salzburg, Austria. MRI scans performed within 48 hours of SE diagnosis were evaluated for PMA on diffusion-weighted imaging (DWI), T2-weighted fluid-attenuated inversion recovery (FLAIR), and arterial spin labeling (ASL). The outcome was unprovoked seizures, assessed by retrospective review of hospital records and telephone interviews. Cumulative risk of seizures stratified by PMA occurrence (PMA on DWI/FLAIR, hyperperfusion on ASL, no PMA) was evaluated through survival analysis. Multivariable analysis using logistic regression was conducted to assess the influence of PMA, etiology, semiology, and ictal EEG patterns on seizure occurrence.

Among 135 patients included (median age 70 [interquartile range (IQR) 58-80] years and 55% female), 43 (32%) experienced seizures during a median follow-up of 23 (IQR 9-39) months. The cumulative seizure probability at 1 and 4 years was 34% (95% CI 17-47) and 61% (95% CI 37-75) in patients with PMA on DWI/FLAIR; 0% and 13% (95% CI 0-29) in patients with hyperperfusion on ASL; and 25% (95% CI 14-34) and 36% (95% CI 19-49) in those without PMA. Other SE features associated with higher seizure risk were treatment refractoriness (odds ratio [OR] 2.93, 95% CI 1.23-6.98, p = 0.02), longer SE duration (OR 1.003, 95% CI 1.001-1.004, p = 0.02), and lateralized periodic discharges on ictal EEG (OR 3.59, 95% CI 1.37-9.83, p = 0.005). In multivariable analysis, PMA on DWI/FLAIR (log-odds 1.23, 95% CI 0.13-2.33, p = 0.03) and remote etiology (log-odds 1.85, 95% CI 0.45-3.25, p = 0.009) were independently associated with increased seizure probability.

PMA on DWI or FLAIR were independently linked to a cumulative seizure risk exceeding 60% after de novo SE, consistent with a diagnosis of epilepsy. The findings of our study may help guide long-term treatment decisions in patients with de novo SE.