Acute Demyelinating Encephalomyelitis Post-COVID-19 Vaccination: A Case Report and Literature Review.

New advancements in the medical community have rapidly occurred with the development of medical information across the globe during the COVID-19 pandemic. Several vaccine manufacturers were able to obtain clearance to administer vaccines in selected age groups and for those at high risk for COVID-19 complications. As vaccines became more readily available, there was a significant effort supported by scientific information to get people vaccinated to boost herd immunity. Acute demyelinating encephalomyelitis (ADEM) is a rare autoimmune disease, causing demyelination in the brain and spinal cord, presenting as monophasic, acute-onset, and rapidly progressive multifocal neurological deficits. A wide variety of precipitating factors can trigger ADEM, and it has long been known to be a rare adverse event following some types of vaccinations including rabies, diphtheria-tetanus-polio, smallpox, measles, mumps, rubella, pertussis, influenza, and hepatitis B vaccines. Recently, ADEM has also been associated with COVID-19 infection and (very rarely) with COVID-19 vaccination. We have a 56-year-old female who was not known to have any medical issues. She voluntarily received her first COVID-19 vaccination (AstraZeneca) ten days after immunization; she developed weakness of the lower limbs and slurred speech. She tested negative for COVID-19, and a brain MRI showed T2-weighted white-matter hyperintense lesions suggesting acute demyelinating encephalomyelitis. She was managed with pulse-dose steroids, which resulted in a marked improvement in her symptoms, and discharged in a stable condition. Physicians should be aware of this neurological disorder and the management options for better patient care and outcomes.