Spontaneous subdural effusion in a hospitalized Covid-19 patient: Case report.

Subdural effusions (SE) have already been associated with several viruses, but there are few associations with Covid-19 reported to date, and all of them had one thing in common: the presence of superimposed bacterial rhinosinusitis. Here we describe the case of a 76-year-old male patient that was transferred to our center due to severe SARS-CoV-2 infection and developed a SE during hospital stay. He presented sensory level impairment during hospitalization, but an initial Head CT scan showed no alterations. A new CT scan performed six days later evidentiated a bilateral SE. The patient had a cardiorespiratory arrest during the night of the same day, resulting in death. Covid-19 as a direct cause of subdural effusion (positive Covid-19 PCR in subdural fluid) has never before been reported in the literature, and, unfortunately, it was not possible to rule out or confirm this phenomenon in our case due to the rapid evolution of the clinical picture. However, our case clearly differs from the literature as the patient did not show any signs of sinus disease or intracranial hypotension, and the possible causes of the effusion boil down to spontaneity and the direct action of Covid-19 in the CNS and subdural space.