A case of probable SARS-CoV-2-related post-infectious autoimmune encephalitis with a rise in serum antibodies title

ABSTRACT

Background and aims: Recent reports have linked SARSCoV- 2 infection with para- and post-infectious autoimmune encephalitis, suggesting cytokine storm as a possible pathogenesis. Methods: We describe a patient who developed acute encephalitis three weeks after resolution of SARS-CoV-2 infection symptoms, coincident with a rise in serum anti- SARS-CoV-2 antibodies. Results: A 29 year-old man presented with fluent aphasia and ideo-motor apraxia since awakening in the morning, mimicking a stroke. His brain CT, angio-CT and perfusion CT were all negative;an urgent brain MRI revealed nonspecific FLAIR hyperintensities. After a lumbar puncture, showing 150 lymphocytes and elevated proteins, his symptoms suddenly started improving, with complete resolution two hours later. An urgent EEG showed left temporal slow waves. A SARS-CoV-2 swab turned negative, and he was admitted to the Neurology department with antiviral and antibiotic treatment. His wife had PCRconfirmed Covid-19 infection a month before, and he experienced fever and hyposmia the following week. Over the course of a month he experienced another aphasic episode, resolved with diazepam. Serum SARS-CoV-2 antibodies title increased and decreased over three weeks;notably, serial EEG showed worsening of epileptic activity along with the rise in SARS-CoV-2 antibodies title, despite anti-epileptic treatment. A brain PET was non-significant, and his CSF parameters slowly improved only after a five days cycle of methylprednisolone. Serum anti-surface antigens antibodies and CSF SARS-CoV-2 IgG were negative. Conclusion: The patient was discharged with double antiepileptic therapy after exclusion of known causes of encephalitis (infectious, paraneoplastic, autoimmune);therefore, in our opinion, the most probable diagnosis was SARS-CoV-2-related post-infectious encephalitis. (Figure Presented).