New-Onset Status Epilepticus in Pediatric Patients: Causes, Characteristics, and Outcomes

BACKGROUND: Many pediatric patients presenting with status epilepticus have no history of seizures. METHODS: We retrospectively analyzed the clinical characteristics of patients aged one month to 21 years who presented during six consecutive years with convulsive status epilepticus and without a history of seizures. New-onset refractory status epilepticus was defined as status epilepticus refractory to two lines of treatment, without an identified cause in the first 48 hours. RESULTS: Of 460 patients with status epilepticus, 79 (17.2%) presented with new-onset status epilepticus, including four (0.9%) with new-onset refractory status epilepticus. Of those patients, 54.4% were female, and the median age was 3.5 years (IQR: 1.08 to 6.75). The median seizure duration was 20 minutes (IQR: 10 to 40 minutes). Etiology was unknown in 36.7%, symptomatic in 303%, provoked in 16.5%, and provoked with an existing symptomatic etiology in 16.5%. Patients were followed for a median duration of 63 months (IQR: 21 to 97). The mortality rate was 3.8%. Of 55 patients who were developmentally normal at baseline, 29.1% had a significant cognitive impairment at the last follow-up, and 20% had academic difficulties or behavioral problems. Patients with symptomatic etiology had greater odds of having cognitive and behavioral problems compared with patients with unknown etiology (odds ratio = 3.83, P = 0.012). CONCLUSIONS: Patients with new-onset status epilepticus are at risk for recurrent seizures, recurrent status epilepticus, death, and subsequent cognitive-behavioral impairment. Specific monitoring and care interventions might be required in this high-risk population.