Anti N-Methyl-D-Aspartate receptor antibody associated Acute Demyelinating Encephalomyelitis in a patient with COVID-19: a case report

BACKGROUND: Anti N-Methyl-D-Aspartate (NMDA) receptor antibody associated ADEM is a diagnosis that was first described relatively recently in 2007 by Dalmau et al. The recent COVID-19 pandemic has resulted in multiple neurological complications being reported. However, there is limited data on Anti-NMDA receptor antibody associated ADEM in COVID-19 patients. Furthermore, the MRI findings in these patients have not been fully elucidated. This case report adds to the growing body of knowledge of neurological complications in COVID-19 patients. CASE PRESENTATION: A 50 year old Caucasian female with no previous medical co-morbidities presented with symptoms of COVID-19 and subsequently developed neurological symptoms which included confusion, limb weakness and seizures. The patient developed marked behavioural abnormalities which required attention. She was found to have anti NMDA receptor antibodies present in a significant titres, an elevated total protein on lumbar puncture and cytotoxic magnetic resonance imaging (MRI) changes in the brain and spinal cord and was subsequently diagnosed with an anti-NMDA Receptor Antibody associated ADEM. The bilateral symmetric involvement of the corticospinal tract on MRI was considered unusual in our case. She was treated with a combination of corticosteroids and plasmapheresis which halted disease progression. Thereafter she was commenced on intravenous immunoglobulin as maintenance therapy and she has shown continuous improvement with ongoing physiotherapy. CONCLUSION: The recognition of COVID 19 neurological complications may be difficult in the initial disease as early symptoms of lethargy, weakness and confusion may be very nondescript. However, it is imperative that these complications are sought for as they are imminently treatable. Early institution of therapy is imperative in decreasing long term neurological consequences.