Abstracts

Rationale: Previous studies of status epilepticus (SE) in patients without a history of seizures mostly investigated adult populations. The aim of this study was to describe clinical characteristics of a pediatric cohort with new-onset SE. Methods: We retrospectively studied patients aged 1 month to 21 years presented to our center during 6 consecutive years with at least one episode of convulsive SE and without prior history of seizures. SE was defined as continuous convulsive seizure activity of ?- 5minutes duration or series of convulsive seizures each lasting less than 5 minutes but recurring without return to baseline between episodes. New-Onset Refractory Status Epilepticus (NORSE) was defined as SE which is refractory to two lines of treatment, without an identified cause in the first 48 hours of evaluation. We also reviewed follow-up information. Results: 460 patients with SE were identified, and 79 (17.2%) presented with new-onset SE, including 4 patients (0.9%) with NORSE. Of those, 54.4% were female, and the median age was 3.5 years (IQR: 1.08-6.75). Median seizure duration was 20 minutes (IQR: 10-40). Etiology was unknown in 36.7%, symptomatic in 30.3%, provoked in 16.5%, and provoked in the setting of an existing symptomatic etiology in 16.5%. EEG was abnormal in 70.9% of the patients, while MRI was abnormal in 54.7%. Patients were followed for a median duration of 63 months (IQR: 21-97). Overall, the mortality rate was 3/79 (3.8%). Of 55 patients who were developmentally normal at baseline, 16 (29.1%) had developmental regression or significant cognitive impairment at last follow-up, and 11 (20%) had academic difficulties or behavioral problems. Patients with symptomatic etiology had greater odds of having cognitive and behavioral problems at last follow-up compared to those with unknown etiology. There was no difference between patients with provoked SE and SE of unknown etiology (symptomatic vs. unknown, OR=3.83, p=0.012; provoked vs. unknown, OR=0.62, p=0.50). A logistic regression analysis using age, etiology, duration of SE, development at baseline, and duration of follow-up revealed follow-up duration as a predictor of neurocognitive outcome (OR=1.02, p=0.015). Most patients (92.3%, 95% CI: 84-97%) experienced recurrent seizures, and 70.5% (95% CI: 59.1-80.3%) experienced recurrence of SE during the follow-up period. There was no difference in the recurrence of seizures or SE among different etiologies (p=0.118 and 1.00, respectively). Conclusions: Presentation of status epilepticus without previous seizure history is common in pediatric patients. Patients are at risk of recurrent seizures, recurrent SE, death, as well as subsequent cognitive or behavioral impairment. Next steps may include specific monitoring and care interventions in this high-risk population. Funding: None