Cerebral vasculitis (CV) is a severe complication of pneumococcal meningitis (PM); whether dexamethasone use can reduce its occurrence remains to be determined.

This is a retrospective observational bicentric study analyzing all adults with proven PM hospitalized between January 2002 and December 2020 in two tertiary hospitals. Extrapolating from a standardized definition of primary angiitis of the central nervous system, we defined CV as worsened neurological symptoms associated with compatible imaging. All images were analyzed by a radiologist, and two neurologists reviewed all inconclusive cases of suspected CV for adjudication. Factors associated with CV were analyzed, including dexamethasone use. A subgroup analysis was limited to patients with a lumbar puncture at PM diagnosis.

Among 168 patients with PM, 49 (29.2%) had CV, occurring after a median of 8 days (IQR 5–13) of PM diagnosis. In multivariate analysis (N = 151), initial CRP was associated with CV (OR 1.28 per 50-unit increase, p = 0.003), which was marginally linked with delayed hospital admission more than 48 hours after first symptoms (OR 2.39, p = 0.06) and prior NSAID intake (OR 2.94, p = 0.05). Dexamethasone administration did not impact CV occurrence. In 133 patients having undergone lumbar puncture, CSF protein level > 4.4 g/L (OR 4.50, p = 0.006) was associated with CV.

In our cohort, CV was a frequent and severe complication of PM, often occurring in association with unduly delayed medical care, high CRP at admission, and high levels of protein in CSF.