Good Outcomes in Bacterial Meningitis and CSF Leakage

Bacterial meningitis in patients with cerebrospinal fluid (CSF) leakage has a high recurrence rate but a generally favorable outcome, according to a study published in Clinical Infectious Diseases.

CSF leakage is a risk factor for bacterial meningitis. Anatomic defects of the skull caused by congenital abnormalities that allow contiguous spread of infection from ear and sinus infections, neurosurgery, ear-nose-throat surgery, or neurotrauma can all lead to CSF leakage. Although CSF leakage can go unnoticed, symptoms such as rhinorrhea and otorrhea may be associated with it. Previously, CSF leakage was been reported in 3% to 8% of patients with community-acquired bacterial meningitis and in 38% of patients with recurrent meningitis. CSF leakage from head trauma that results in skull base fracture usually resolves spontaneously within 24 hours, but once persistent, meningitis occurs in 7% to 30% of patients. Therefore, this study analyzed episodes of community-acquired bacterial meningitis associated with CSF leakage from a prospective nationwide cohort study.

A nationwide, observational, cohort study in The Netherlands, called the MeninGene Study, prospectively included 2022 episodes of community-acquired bacterial meningitis over a 12-year period. Excluded from this study were patients with hospital-acquired meningitis, patients with a recent (within 1 month) neurosurgery or head injury, and patients with neurosurgical devices. Patient characteristics, symptoms and signs on admission, laboratory results, radiologic examination, treatment, and outcome data were collected. If CSF leakage was reported, additional information was collected retrospectively. All discharge letters were screened for cause, duration, and presence of liquorrhea, number of recurrent episodes, vaccination, and treatment. To determine outcome, a neurologic examination was performed at discharge and the outcome was graded according to the Glasgow Outcome Scale, with outcome scores ranging from 1 (death) to 5 (good recovery). A favorable outcome was scored as a 5, while unfavorable outcomes were scored 1 through 4. The Mann-Whitney U test for continuous data was used to identify differences between episodes in patients with and without CSF leak associated with bacterial meningitis.

Results showed that despite surgical repair or vaccination, bacterial meningitis in patients with CSF leakage has a high recurrence rate, but the outcome is generally favorable. Among 53 patients, CSF leakage was identified in 65 of 2022 episodes (3%). The cause of CSF leakage was identified in 75% of these episodes, which most commonly consisted of ear-nose-throat surgery (29%) and remote head trauma (23%). Of the 65 episodes identified, 59% were recurrent meningitis episodes; in 71% of these, there was known CSF leakage and in 53%, previous surgery had been performed to close the leak. Of the patients who had known CSF leakage, 38% had been vaccinated: all 9 patients were vaccinated with 23-valent pneumococcal vaccine, 2 patients were vaccinated with meningococcal serogroup C vaccine, and 1 patient was vaccinated with meningococcal serogroup A and Haemophilus influenzae type b vaccine. In 51% of the episodes, Streptococcus pneumoniae was cultured and in 17% of the episodes, H influenzae was cultured. Although no patients died, the outcome was unfavorable in 12% of episodes.

Overall, the study authors concluded that, “CSF leakage should be suspected in patients with bacterial meningitis presenting with liquorrhoea, recurrent meningitis or with disease caused by H influenzae.”

Reference

Ter Horst L, Brouwer MC, van der Ende A, van de Beek D. Community-acquired bacterial meningitis in adults with cerebrospinal fluid leakage [published online July 12, 2019]. Clin Infect Dis. doi:10.1093/cid/ciz649