Background: To describe the prevalence, clinical characteristics, impact of systemic steroids exposure and outcomes of delayed cerebral vasculopathy (DCV) in a cohort of adult patients with pneumococcal meningitis (PM). Methods: Observational retrospective multicenter study including all episodes of PM from January 2002 to December 2015. DCV was defined as proven/probable/possible based upon clinical criteria and pathological-radiological findings. DCV-patients and non-DCV-patients were compared by univariate analysis. Results: 162 PM episodes were included. Seventeen (10.5%) DCV-patients were identified (15 possible, 2 probable). At admission, DCV-patients had a longer duration of symptoms (>2 days in 58% vs. 25.5% (p 0.04)), more coma (52.9% vs. 21.4% (p 0.03)), lower median CSF WBC-count (243 cells/uL vs. 2673 cells/uL (p 0.001)) and a higher proportion of positive CSF Gram stain (94.1% vs. 71% (p 0.07)). Median length of stay was 49 vs. 15 days (p 0.001), ICU admission was 85.7% vs. 49.5% (p 0.01) and unfavorable outcome was found in 70.6% vs. 23.8% (p 0.001). DCV appeared 1-8 days after having completed adjunctive dexamethasone treatment (median 2,5, IQR = 1.5-5). Conclusions: One tenth of the PM developed DCV. DCV-patients had a longer duration of illness, were more severely ill, had a higher bacterial load at admission and had a more complicated course. Less than one third of cases recovered without disabilities. The role of corticosteroids in DCV remains to be established.

Changes in aircraft cabin pressure may result in bacterial meningitis in passengers with particular risk factors. The participation of multiple factors stands out, such as barotrauma, ear nose throat bacteria and cerebrospinal fluid (CSF) leakage. As this is a neglected topic in aviation medicine, a synopsis of cases observed and previously published is presented.