New-onset refractory status epilepticus (NORSE) in paediatric patients: causes, characteristics and outcomes.

Background: New-onset refractory status epilepticus (NORSE) refers to patients without a previous history of seizures who have refractory status epilepticus for at least 72 hours without an identified aetiology. Despite the severe neurological sequelae of NORSE, little is known about this condition in paediatric patients.

Objective: To describe the profile of paediatric patients with NORSE, the profile of seizures, possible causes attributed to this condition, treatments offered to patients and the outcomes at discharge from the paediatric intensive care unit (PICU).

Methods: This retrospective, multicentre, descriptive study (case series) was conducted in the PICUs of three tertiary hospitals. We reviewed the medical records of all patients aged 0-16 years admitted to the participating PICUs between December 2013 and December 2017 with refractory status epilepticus, without a previous history of seizures or neurological disease.

Results: Fifteen patients (2.4%) had NORSE. The median age of patients was 62.3 (IQR 26.2-75.4) months. All patients experienced prodromes before progressing to refractory status epilepticus. Twelve patients (80%) had fever up to 24 hours before seizures. NORSE was classified as cryptogenic in 66% of patients. Twelve patients were treated with complementary therapies, in addition to anticonvulsants. There was no standardisation in the treatment of patients. The overall mortality rate was 20%.

Conclusions: NORSE is associated with high morbidity and mortality, without an identified aetiology in most cases and with a wide range of proposed therapies.