Meningitis incidence in cranial base fracture: a systematic review and meta-analysis

Background: Cranial base fractures are primary brain injuries with high importance in neurotrauma. They occur in 3.5-24% of head injuries and are often related to brain injury. Based on location, cranial base fractures occur 70% in the anterior fossa, 20% in the middle central cranial base and 5% in the middle and posterior fossa. The dura mater at the cranial base is significantly thinner than the dome area and easier to cause meningitis when torn due to CSF (Cerebrospinal Fluid) leak. Post-traumatic meningitis refers to the meningeal infection caused by craniocerebral trauma. Therefore, we decided to analyze meningitis as a complication of CSF leakage in cranial base fracture. Methods: This systematic review and meta-analysis were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. A thorough literature search was conducted on PubMed, Cochrane and Google scholar. Articles were systematically selected based on the PRISMA protocol and reviewed completely. The articles that met the criteria were summarized and analyzed. The primary outcome measured was CSF, leakage event and Cranial Base Fractures, while the secondary outcome was a meningitis event. This study hasn’t been registered to PROSPERO. Result: There were 15 literatures included in this research. From quantitative analysis, we found that the Risk Ratio (RR) for meningitis incidence in the CSF leakage group was 16.18 (95% CI 1.31 to 199.85). RR for meningitis incidence in the anterior cranial base fracture group was 2.59 (95% CI 1.64 to 4.09). In the antibiotic prophylaxis group, the RR for meningitis incidence was 0.67 (95% CI 0.49 to 0.90). CSF leakage incidence had an RR of 1.39 (95% CI 0.90 to 2.16) in the anterior cranial base fracture group. While RR for meningitis incidence in the surgical management of the CSF leakage group was 1.77 (95% CI 0.87 to 3.61). Conclusion: There was a significant risk of post-traumatic meningitis in patients with cranial base fractures with CSF leakage compared to those without CSF leakage. Patients with anterior fossa cranial base fractures had a significantly higher risk of post-traumatic meningitis than the posterior fossa. There is a significant risk reduction of developing post-traumatic meningitis in patients with cranial base fractures who were given prophylactic antibiotics compared to those without prophylactic antibiotics. In contrast, CSF leak risk was higher in patients with anterior fossa cranial base fractures compared to the posterior fossa, but not statistically significant. The risk of post-traumatic meningitis in patients with cranial base fractures who underwent surgical treatment was higher than in the conservative group.