Pneumocephalus as uncommon presentation of pneumococcal meningitis

Sir, Pneumocephalus is an uncommon, often forgotten complication of meningitis caused by gas-producing organisms.[1] An 80-year-old woman, without any significant medical history, was admitted in a comatose state with fever. The brain and skull base computed tomography (CT) scan revealed multiple hypodense areas of air densities in the basilar cistern and along the cerebellar tentorium [Figure 1], without any bone defect. Magnetic Resonance Imaging (MRI) revealed right mastoiditis and left ethmoid sinusitis. Lumbar cerbrospinal fluid examination was positive for Streptococcus Pneumoniae (antigens and cultures). The patient was successfully treated with ceftriaxone/metronidazole and discharged a month later. The follow-up brain CT scan was unremarkable. Pneumocephalus mostly arises as a complication of trauma, surgery and less frequently, of neoplasm, otitis media, post-radiation necrosis or sinusitis. Rarely have there been case reports of pneumocephalus associated with pneumococcal meningitis in immunocompetent patients with concomitant sinusitis or mastoiditis.[2,3] The presence of bone dehiscence in the lateral sphenoid or temporal bones was detected in such cases and it was supposed to have been the cause of pneumocephalus.[4] In our patient, neuroimaging revealed mastoiditis and left ethmoid sinusitis, in the absence of any apparent osseous breach due to the inflammatory process. Spontaneous, non-traumatic pneumocephalus should raise the suspicion of meningitis and prompt adequate treatment, especially in the presence of suggestive clinical signs.