Autoimmune Encephalitis Presenting with Malignant Catatonia in a 40-Year-Old Male Patient with Covid-19

Acute malignant catatonia with autonomic instability developed in a previously healthy man with PCR-verified SARS-CoV-2. CT and MRI were normal, EEG showed slowing and cerebrospinal fluid showed a subtle indication of inflammation. There were no signs of pathology in other organs.¹⁸F-FDG-PET conveyed high bilateral uptake in the striatum. While commercial tests were negative, immunohistochemical staining of mouse brain revealed anti-neuronal IgG antibodies against neuronal targets in the hippocampus, thalamus, striatum and cortex. Early treatment with plasmapheresis and corticosteroid reversed disease progression and may have prevented large-scale neurological damage. We are not aware of other types of encephalitis with such distinct pyramidal tract symptoms and raise the possibility that this may be a novel form of autoimmune encephalitis induced by infection with SARS-CoV-2.