Isolated Central Nervous System Vasculitides in COVID-19: A Systematic Review of Case Reports and Series

Cerebral vasculitides, both isolated or in systemic disorders, could be triggered by infections, and few cases have been associated to coronavirus disease 2019 (COVID-19). This study searched for publications in Pubmed, EMBASE, and Cochrane library databases for case reports and series of isolated central nervous system (CNS) vasculitides triggered by severe acute respiratory syndrome coronavirus-2. We included 12 studies (published from June 2020 to July 2022) and collected 39 adult patients (5/39 pathologically or radiologically proven, 34/39 suggestive for primary CNS vasculitis or PCNSV). All cases had a positive real-time polymerase chain reaction on a nasopharyngeal swab or a respiratory tract specimen. About the 85% of the included cases were males, and disease onset occurred later than 50 years old in all but three subjects. In total, 33/39 patients presented severe COVID-19 pneumonia, frequently requiring intensive care unit care. The most common neurological features were headache, obnubilation, and coma. PCNSV was suspected mainly on radiological findings, whereas the cerebrospinal fluid analysis was minimally altered. Magnetic resonance imaging showed vessel wall enhancement in 32/39 cases, generally with the concomitant presence of microbleeds, subarachnoid haemorrhages, and/or multiple ischemic lesions. Despite the severe respiratory and neurological disease course, most cases (93%) improved spontaneously or after a course of high-dose intravenous steroids with no need for immunosuppression. In conclusion, PCNSV could rarely relate to COVID-19 and independently from pulmonary disease severity. Adults with COVID-19-related PCNSV could have a favourable prognosis.