New-Onset Refractory Status Epilepticus After Pfizer-BioNTech COVID-19 Vaccination

ABSTRACT

Objective: NA Background: Previous case reports have described 3 cases of autoimmune encephalitis and 1 case of new-onset refractory status epilepticus (NORSE) following COVID-19 viral vector vaccinations. However, no cases have been documented in association with COVID-19 mRNA vaccinations. We describe a case of NORSE after vaccination with Pfizer-BioNTech COVID-19 vaccine. Design/Methods: Case report. Results: A 56 year old healthy man presented with three days of fever, fatigue, and aphasia beginning 2 weeks after he received his first dose of the Pfizer-BioNTech COVID-19 vaccine. Video EEG showed temporally predominant seizures occurring independently bilaterally (right greater than left). Clinical seizures were characterized by head turn to the left and right hand movements. He then developed sustained right frontotemporal spike and slow wave activity consistent with non-convulsive status epilepticus. CSF demonstrated mild lymphocytic pleocytosis with WBC 16 cells/mm3, protein 24, glucose 76, and an opening pressure of 47. CSF bacterial and viral encephalitis panels, HSV, lyme, West Nile virus, and VDRL were all negative. Oligoclonal bands, paraneoplastic panel, and encephalopathy panel were negative. Systemic malignancy workup was negative. Initial MRI brain was unremarkable, but 1 week after symptom onset he developed bilateral hippocampal edema. The patient was empirically treated with broad spectrum antibiotics and antivirals which were later discontinued. Due to presumed diagnosis of autoimmune encephalitis, he was treated with high dose steroids, plasmapheresis, IVIG, and rituximab. He was treated with progressively escalating anti-seizure medications including midazolam, propofol, and ketamine continuous infusions and eventually stabilized on levetiracetam, lacosamide, phenobarbital, clobazam, zonisamide, oxcarbazepine, and perampanel. At the time of discharge, mental status had improved and aphasia resolved. Conclusions: To our knowledge, this is the first case of NORSE reported after Pfizer COVID-19 vaccination. While no test exists to definitively establish causality, these findings warrant further investigation of the possible association between COVID-19 vaccination and autoimmune encephalitis.