A case of neuromyelitis optica spectrum disorder (NMOSD) and acute myositis following SARS-CoV-2 infection

ABSTRACT

Background and aims: Neurological manifestations of COVID-19 have been described. We report a case of seropositive NMOSD and acute myositis following SARS-CoV-2 infection. Methods: A previous healthy 35-years old man was admitted for NORB, a month after paucisymptomatic SARS-CoV-2 infection. Nasopharyngeal tests for SARS-CoV-2 was negative and serological IgG and IgM were positive. The neurological examination showed left eye blindness and myalgia. Blood examination showed elevated CK (>1000 UI/l), positive ANA (1640) and anti-TPO (>1300 U/ml). Brain MRI showed T2/FLAIR left optic nerve hyperintensity with contrast enhancement. The EMG revealed signs of acute myogenic damage. He received intravenous methylprednisolone with poor recovery on vison but full recovery on muscle symptoms. Four months later he present NORB in contralateral eye;MRI showed optic chiasm hyperintensity, serum anti-AQP-4-antibodies were positive, EMG and CK were normalized. The patient received intravenous steroids and Immunoglobulins and started rituximab. Nevertheless, three months later he developed the area postrema syndrome, he was retreated with intravenous steroids and immunoglobulins and achieved a complete recovery. In March 2021, he underwent the second course of rituximab with clinical and radiological stability. Results: The patient was diagnosed with seropositive NMOSD, presented with recurrent NORB and area postrema syndrome, associated to acute myositis and autoimmune tiroiditis after SARS-CoV-2 infection. Conclusions: We supposed that SARS-CoV-2 may cause a post-infectious autoimmune response directed against AQP4 and other target (the muscle, the tiroid gland). Post-infectious autoimmunity is a potential mechanism in a subset of patients with COVID-19-related neurologic disease. Further research is needed to clarify this association.