Cerebrospinal Fluid Anti-Neuronal Autoantibodies in COVID-19-Associated Limbic Encephalitis with Acute Cerebellar Ataxia and Myoclonus Syndrome: Case Report and Literature Review

Abstract

Since the outbreak of coronavirus (COVID-19) in 2019, various rare movement disorders and cognitive changes have been recognized as potential neurological complications. The early treatment of some of these allows rapid recovery; therefore, we must diagnose these manifestations in a timely way. We describe the case of a 76-year-old man infected with severe acute respiratory syndrome coronavirus-2 who presented with confusion and hallucinations and was admitted to our hospital 14 days after the onset of symptoms. One day later, he developed generalized myoclonus, dysarthria and ataxia, and tonic clonic seizures and was admitted to the intensive care unit. A diagnosis of COVID-19-associated autoimmune encephalitis with characteristics of limbic encephalitis and immune-mediated acute cerebellar ataxia and myoclonus syndrome was supported by alterations in the limbic system shown in magnetic resonance imaging, lateralized discharges shown in electroencephalography, a slightly elevated protein level in the cerebrospinal fluid (CSF), and indirect immunofluorescence in the CSF with autoantibody binding to anatomical structures of the cerebellum and hippocampus. The patient improved with 2 weeks of corticosteroid treatment and four sessions of plasmapheresis. Our current case study describes a rare case of COVID-19-related limbic encephalitis with immune-mediated acute cerebellar ataxia and myoclonus syndrome (ACAM syndrome) and strengthens the need for tissue-based assays (TBAs) to screen the serum and/or CSF of patients highly suspected to have autoimmune encephalitis. We believe that the timely diagnosis and targeted aggressive immunotherapy were mainly responsible for the patient’s total recovery.

COVID-19: Unveiling the Neuropsychiatric Maze—From Acute to Long-Term Manifestations

“…Similarly, cases of auto-antibody-mediated encephalitis have been reported in patients with COVID-19 [ 68 , 69 , 70 ] or following vaccination [ 71 , 72 ], as well as myelopathy with antibodies against oligodendrocytic glycoprotein (MOG) after SARS-CoV-2 infection [ 73 ]. Implicated antibodies include anti-N-methyl-D-aspartate receptor (NMDAR) antibodies, MOG antibodies, anti-amphiphysin antibodies, and antibodies against contactin-associated protein-like 2 (Caspr2) [ 74 ].…”

“…There is also increasing evidence of post-COVID-19 autoimmune antibody-mediated encephalitis, with elevated levels of these antibodies [ 68 , 69 , 70 ], which may also apparently be induced by anti-COVID vaccines as an infrequent complication. Therefore, there is no doubt that the benefits of COVID-19 vaccination outweigh the risks of neurological complications [ 72 , 91 ].…”