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Clinical presentation of new onset refractory status epilepticus in children (the pSERG cohort)
Claudine Sculier1,2, Cristina Barcia Aguilar1,3, Nicolas Gaspard2,4
1Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
Insights
New onset refractory status epilepticus (NORSE) in children is often of unknown cause and associated with fever. Fever preceding seizures indicates prolonged episodes and poorer outcomes in pediatric patients.
Area of Science:
- Pediatric Neurology
- Epileptology
- Critical Care Medicine
Background:
- New Onset Refractory Status Epilepticus (NORSE) is a rare but severe neurological emergency in children.
- Understanding the clinical profile and outcomes of pediatric NORSE is crucial for effective management.
- The role of fever in the etiology and prognosis of NORSE requires further investigation.
Purpose of the Study:
- To characterize the clinical presentation and outcomes of pediatric NORSE.
- To investigate the association between fever onset and the characteristics of status epilepticus (SE).
- To differentiate subgroups within NORSE based on fever timing and its impact on outcomes.
Main Methods:
- Prospective enrollment of pediatric patients with refractory SE (RSE) into the pSERG cohort.
- Classification of NORSE cases into "known etiology" and "unknown etiology."
- Subgroup analysis of NORSE of unknown etiology based on fever occurrence relative to RSE onset (at onset, previous, or no fever).
Main Results:
- 46 out of 279 RSE patients met NORSE criteria (16%); 87% were of unknown etiology.
- Fever at SE onset (48%) was associated with younger age, shorter SE duration, and better recovery (89% baseline function).
- Preceding fever (40%) correlated with prolonged SE, worse outcomes, and lower recovery rates (25% baseline function).
Conclusions:
- Pediatric NORSE, particularly of unknown etiology, is frequently associated with fever.
- Fever timing is a significant factor influencing SE duration and neurological outcomes in pediatric NORSE.
- Fever occurring >24 hours before seizures may identify a subgroup with distinct clinical features and poorer prognosis, potentially overlapping with FIRES.
Objective:
We aimed to characterize the clinical profile and outcomes of new onset refractory status epilepticus (NORSE) in children, and investigated the relationship between fever onset and status epilepticus (SE).
Methods:
Patients with refractory SE (RSE) between June 1, 2011 and October 1, 2016 were prospectively enrolled in the pSERG (Pediatric Status Epilepticus Research Group) cohort. Cases meeting the definition of NORSE were classified as "NORSE of known etiology" or "NORSE of unknown etiology." Subgroup analysis of NORSE of unknown etiology was completed based on the presence and time of fever occurrence relative to RSE onset: fever at onset (≤24 h), previous fever (2 weeks-24 h), and without fever.
Results:
Of 279 patients with RSE, 46 patients met the criteria for NORSE. The median age was 2.4 years, and 25 (54%) were female. Forty (87%) patients had NORSE of unknown etiology. Nineteen (48%) presented with fever at SE onset, 16 (40%) had a previous fever, and five (12%) had no fever. The patients with preceding fever had more prolonged SE and worse outcomes, and 25% recovered baseline neurological function. The patients with fever at onset were younger and had shorter SE episodes, and 89% recovered baseline function.
Significance:
Among pediatric patients with RSE, 16% met diagnostic criteria for NORSE, including the subcategory of febrile infection-related epilepsy syndrome (FIRES). Pediatric NORSE cases may also overlap with refractory febrile SE (FSE). FIRES occurs more frequently in older children, the course is usually prolonged, and outcomes are worse, as compared to refractory FSE. Fever occurring more than 24 h before the onset of seizures differentiates a subgroup of NORSE patients with distinctive clinical characteristics and worse outcomes.
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