Determinants for Control of Status Epilepticus in Patients with Anti-N-Methyl-D-Aspartate Receptor Encephalitis

Treatment guideline for status epilepticus (SE) specifically in patients with anti-N-methyl- D-aspartate receptor (anti-NMDAR) encephalitis is insufficient. This study aimed to clarify the determinants for the control of SE in adult patients with anti-NMDAR encephalitis.

Medical records of all patients with anti-NMDAR encephalitis hospitalized between Jan. 2010 and Sep. 2019 were analyzed for the time sequence of seizures and treatments, and antiepileptic drug (AED) regimens related to SE. The outcomes were control of SE and seizures, and the discharge score of modified Rankin Scale (mRS).

All eight patients had seizures and seven (87.5%) suffered from SE which lasted for 3.6 ± 3.9 days. Five patients (71.4%) had SE earlier than using IT, whose SE was controlled by AEDs alone (n = 4) or combined with teratomas resection (n = 1). Another two patients suffered from SE after receiving IT, and one of them had SE only for 1 hour. Moreover, all SE patients received increased types and dosages of AEDs at SE end. A shorter duration of refractory SE was associated with its later occurrence after seizure onset (p = 0.005) and longer duration of AEDs use before SE (p = 0.026). All cases achieved seizure freedom after receiving AEDs and IT.

In these patients with anti-NMDAR encephalitis, all the SE which occurred before initiating IT was successfully controlled by AEDs alone or combined with teratoma resection, and later onset of refractory SE was associated with a shorter SE duration.