Abstract
Objective: To report the distinctive clinical features of cryptogenic new-onset refractory status epilepticus (C-NORSE) and the C-NORSE score based on initial clinical assessments.
Methods: A retrospective study was conducted for 136 patients with clinically suspected autoimmune encephalitis who underwent testing for autoantibodies to neuronal surface antigens between January 1, 2007, and August 31, 2016. Eleven patients with C-NORSE were identified. Their clinical features were compared with those of 32 patients with anti-NMDA receptor encephalitis (NMDARE).
Results: The clinical outcome of 11 patients (median age, 27 years; 7 [64%] women) with C-NORSE was evaluated after a median follow-up of 11 months (range, 6–111 months). Status epilepticus was frequently preceded by fever (10/11 [91%]). Brain MRIs showed symmetric T2/fluid-attenuated inversion recovery hyperintensities (8/11 [73%]) and brain atrophy (9/11 [82%]). Only 2 of the 10 treated patients responded to the first-line immunotherapy, and 4 of the 5 patients treated with IV cyclophosphamide responded to the therapy. The long-term outcome was poor in 8 patients (73%). Compared with 32 patients with NMDARE (median age, 27 years; 24 [75%] women), those with C-NORSE had more frequent prodromal fever, status epilepticus, ventilatory support, and symmetric brain MRI abnormalities, had less frequent involuntary movements, absent psychobehavioral symptoms, CSF oligoclonal bands, or tumor association, and had a worse outcome. The C-NORSE score was higher in patients with C-NORSE than those with NMDARE.
Conclusions: Patients with C-NORSE have a spectrum of clinical-immunological features different from those with NMDARE. The C-NORSE score may be useful for discrimination between them. Some patients could respond to immunotherapy.
GLOSSARY
- AE=
- autoimmune encephalitis;
- AED=
- antiepileptic drug;
- AERRPS=
- acute encephalitis with refractory repetitive partial seizures;
- AMPAR=
- α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor;
- C-NORSE=
- cryptogenic new-onset refractory status epilepticus;
- DESC=
- devastating epileptic encephalopathy in school-age children;
- FIRES=
- febrile infection-related epilepsy syndrome;
- GABAaR=
- γ-aminobutyric acid A receptor;
- GABAbR=
- γ-aminobutyric acid B receptor;
- GCSE=
- generalized convulsive status epilepticus;
- HSV=
- herpes simplex virus;
- IL=
- interleukin;
- IVCPA=
- IV cyclophosphamide;
- IVIg=
- IV immunoglobulin;
- IVMP=
- IV high-dose methylprednisolone;
- LGI1=
- leucine-rich glioma-inactivated 1;
- mRS=
- modified Rankin Scale;
- NMDARE=
- anti-NMDA receptor encephalitis;
- NSA=
- neuronal cell-surface antigen;
- OCB=
- oligoclonal band;
- PLEX=
- plasma exchange;
- RSE=
- refractory status epilepticus;
- SE=
- status epilepticus;
- STESS=
- Status Epilepticus Severity Score
Footnotes
Funding information and disclosures are provided at the end of the article. Go to Neurology.org/nn for full disclosure forms. The Article Processing Charge was funded by the authors.
Supplemental data at Neurology.org/nn
- Received June 26, 2017.
- Accepted in final form August 2, 2017.
- Copyright © 2017 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.
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