Acute disseminated encephalomyelitis (ADEM) is an inflammatory disease of the central nervous system thought to be caused by environmental factors to genetic susceptible individuals, where there is autoimmunity towards myelin components. Given the wide variety of symptoms, etiology and mimickers, ADEM is a diagnosis of exclusion, making difficult a prompt diagnosis. The pathogenesis associated between COVID-19 and ADEM is unknown, however, it could be secondary to immune-mediated mechanisms or molecular mimicry, creating a neuro-inflammatory response.

A previously healthy 22-year-old Puerto Rican male presented to the ED with altered mental status, incoherent speech, imbalance, and dizziness of 2 months progression. Neurological examination was remarkable for slow mentation, positive right Hoffman, left leg weakness and bilateral sustained clonus. Brain MRI showed innumerable foci of increased T2/FLAIR signal intensity throughout supra and infratentorial gray and white matter, none showing contrast enhancement. CSF with evidence of high protein levels, WBC of 7 (100% mononuclear) and normal glucose levels. Extensive workup for evaluation of infectious, demyelinating, inflammatory and vascular etiologies came back negative. Patient with recent history of gastrointestinal symptoms, reason why COVID-19 IgG/IgM Rapid Test was performed with positive IgG results 2 months prior to our evaluation. Patient was treated with intravenous steroids and intravenous immunoglobulin, with marked clinical improvement. 

Here we present a case of atypical coronavirus disease 2019 (COVID-19) manifestation of a Puerto Rican male patient that 2 weeks after detecting SARS-COV-2 on his blood neurological symptoms started to develop. This is the first case of a young Puerto Rican patient without any other comorbidities where an association of COVID-19 infection and ADEM was found. Since ADEM if a diagnosis exclusion, it is vital to being able to distinguish this syndrome when it comes to a patient with history of COVID-19 infection and vaccine for prompt management.