Prediction of long-term unprovoked seizures after status epilepticus

Objective: Possible long-term consequences of status epilepticus (SE) include cognitive and behavioral impairment and the development of chronic epilepsy. However, these aspects have not been systematically studied in clinical practice. We aimed to evaluate long-term seizure recurrence after SE and the potential risk factors for their development.Methods: Data were obtained from a prospective registry of all SE episodes occurring in adult patients who attended our center from February 2011 to April 2022. Clinical data, electroencephalographic findings, treatment, and long-term data were prospectively recorded. We performed a cross-sectional study of consecutive SE patients without previous epilepsy diagnosis, and analyzed the development of unprovoked remote seizures.Results: A total of 849 patients were registered in the database. After excluding in-hospital mortality (198/849, 23.3%) and patients with prior epilepsy history (291/849, 44.7%), 360 patients (42.4%) with a first SE episode were included. The median age was 68 years (interquartile range [IQR] = 56-79), and 176 patients (48.9%) were women. The median time to first-line treatment initiation was 2 h (IQR = .7-7.4), and it was correlated with SE duration (R = .375, p < .001). One hundred nine patients (30.3%) presented unprovoked seizures during a median follow-up of 1.8 years (IQR = .5-4.3). After adjusting for identifiable confounders in a multivariable Cox regression analysis, progressive symptomatic etiology (hazard ratio [HR] = 1.97, 95% confidence interval [CI] = 1.17-3.33, p = .011), time to first-line treatment initiation > 1.5 h (HR = 1.89, 95% CI = 1.25-2.87, p = .003), and superrefractory SE (HR = 2.34, 95% CI = 1.26-4.33, p = .007) were independently associated with a greater risk of unprovoked seizure recurrence. In contrast, older patients (HR = .99, 95% CI = .97-.99, p = .021) and an acute symptomatic etiology (HR = .44, 95% CI .28-.68, p < .001) were at lower risk of unprovoked seizure recurrence.Significance: The etiology of SE, the delay in initiating SE treatment, and the presence of superrefractoriness have been identified as potentials factors associated with unprovoked remote seizures following a new onset SE. Therefore, prompt and appropriate management should be applied to avoid seizure recurrence.