Mystery case: frontal meningoencephalocele causing recurrent bacterial meningitis.

A 34-year-old woman presented initially with meningococcal meningitis and with Streptococcus mitis meningitis 6 months later. A right cribriform plate area meningoencephalocele was discovered on MRI at the second episode. In retrospect, this abnormality was present on initial MRI (figure). The patient recalled intermittent watery rhinorrhea for 1 year preceding the first meningitis episode, but without head trauma. The anterior cranial fossa defect was repaired, without recurrence of rhinorrhea or meningitis in 2-year follow-up. Meningoencephalocele may be congenital (incidence 1:5,000 live births) or posttraumatic. It should be sought in recurrent bacterial meningitis by scrutiny of coronal sections of brain MRI.