Abstracts

Rationale: New-onset refractory status epilepticus (NORSE) is a rare entity with a high mortality rate and significant long-term neurological sequelae. Despite extensive workup, more than half of children with NORSE have an unknown etiology. In addition, various treatments showed modest and variable effects, including antiseizure medications (ASMs), anesthetics agents, immunotherapy, and dietary therapy. To our knowledge, no randomized trials have been published about pediatric NORSE in Saudi Arabia. The current study was conducted to determine the most common etiologies, treatments, and outcomes of pediatric NORSE in a tertiary center.

Methods: This is a single-center retrospective cohort study, in which data were retrieved from the medical records of children aged 0-14 years diagnosed with NORSE at King Faisal Specialist Hospital and Research Centre (KFSHRC) between 2009 through 2022.

Results: A total of 423 pediatric patients presented with status epilepticus of which 20 had NORSE. Demographic data included 17 males and 3 females, with a median age of 5.5 years. All patients had no previous significant medical history and were developmentally appropriate for their age. A total of 12 patients had super refractory status epilepticus (SRSE), and 8 patients had refractory status epilepticus (RSE). An extensive workup was conducted, including CSF analysis, autoimmune panel, genetic testing, brain imaging, and continuous EEG monitoring. The most common etiology remained cryptogenic in 10/20, while the most common identifiable etiologies were neurometabolic in 3 patients, autoimmune encephalitis in 3 patients, genetic mutation in 2 patients, and brain tumor in 2 patients. Treatment modalities included multiple ASMs in all 20 patients, anesthetics infusion in 12/20, immunotherapy in 8/20, and one patient was enrolled in the ketogenic diet protocol. All 20 patients developed epilepsy, most of which are controlled on multiple ASMs. Two patients were able to achieve seizure remission and are off ASM. Lastly, neurocognitive and functional deficits were documented in 16/20 patients.

Conclusions: In this single tertiary center experience, an extensive workup yielded an identifiable etiology in half the patients with NORSE, while the remaining half had a cryptogenic etiology. The neurocognitive and functional outcomes were poor regardless of whether an identifiable cause was found. However, patients with SRSE had a worse outcome in this study.

Funding: None.