Meningitis

A 43-year-old African American female came to the emergency department of our institution with 1-week history of headache and fever. On review of systems, she reported that she had been experiencing nasal obstruction and sinusitis-like symptoms for more than 3 months. She had no history of any other significant medical problem.

Physical examination. The patient had a fever of 102ºF and tachycardia. She had signs of meningitis, including altered mental status and photophobia. 

Laboratory tests. Initial laboratory tests showed increased white blood cell (WBC) count and bandemia. The CT scan of the head showed signs of brain swelling and total opacification of the left nasal cavity and left maxillary sinus suggesting sinusitis versus paranasal polyps (Figure 1). A lumbar puncture was performed and the cerebrospinal fluid (CSF) was grossly cloudy with a WBC count of 11,400 (89% neutrophils), low glucose, and high protein. 

Figure 1. A CT scan of the head showed near total opacification of the left nasal cavity (***) and left maxillary sinus (arrow).

Treatment. She was presribed ceftriaxone 2 gms twice a day and rapidly improved. The CSF culture revealed Streptococcus pneumoniae and the treatment with ceftriaxone was continued for 14 days. 

During the antibiotic course, a careful review of the MRI of the sinus and of the head taken during admission suggested a defect in the ethmoid bones, decreased CSF in the anterior fossa, and a possible meningoencephalocele (Figure 2). To confirm the diagnosis, 1.6 mCi of indium DTPA was administered into the thecal sac by lumbar puncture. Scintigraphy and single photon emission CT images confirmed a large left nasal cavity and left maxillary sinus meningocele (Figures 3 and 4). 

The patient underwent bilateral craniotomy and skull and dura mater reparation with thigh muscular and fascia graft without complications. After a 1-year follow-up in the outpatient setting, the patient is completely asymptomatic. 

Figure 2. Magnetic resonance imaging of the brain and sinus showed an abnormal echolucid area in the left nasal cavity (***) with a canal from the anterior cerebral fossa (between arrows).

Figure 3. Brain cisternogram single photon emission CT images showed contrast outside of the brain (arrow). Abnormal area of tracer activity extending anterior and inferiorly (also left to the midline, but not showed in this image) consistent with a large left meningocele extending from the left frontal region into the left nasal cavity.

Discussion. S pneumoniae is a common cause of bacterial meningitis in adults and is associated in more than 25% of cases with upper respiratory tract infections, such as otitis and sinusitis. Though our patient presented with a common illness and a radiologic abnormality that seemed to confirm a common etiology, a high index of suspicion coupled with confirmatory testing in nuclear medicine was required to make the correct diagnosis. 

Figure 4. Brain cisternogram scintigraphy (anterior) 19 hours after the injection of the contrast showed 2 abnormal areas of tracer activity extending anterior and inferiorly to the left, consistent with a large left meningocele extending from the left frontal region into the left nasal cavity (bold arrow) with a smaller component extending from the main left nasal cavity component into the left maxillary sinus (filled arrow). 

Meningocele and encephalocele are rare conditions that are more common in childhood. Patients usually present with perinasal mass(es); its pressure affects facial structures resulting in conditions that can lead to severe outcomes if not correctly identified and treated.^1,2 Meningocele and encephalocele are decidedly uncommon in adults; they are nearly always secondary to trauma and in few described patients, the presentation is with meningitis.^3,4 

Our patient had a very unusual cause of a common disease, reminding us that patients often have not “read the textbook,” and can present in ways that resemble the typical clinical situation, yet turn in unexpected directions.

References:

1.Hamidu AU, Musa A, Tahir MC. Poland's syn1.David DJ, Sheffield L, Simpson D, et al. Frontoethmoidal meningoencephaloceles: morphology and treatment. Br J Plast Surg. 1984;
37(3):271-284. 

2.Holm C, Thu M, Hans A, et al. Extracranial correction of frontoethmoidal meningoencephaloceles: feasibility and outcome in 52 consecutive cases. Plast Reconstr Surg. 2008;121(6):386-395.

3.Hasegawa T, Sugeno N, Shiga Y, et al. Transethmoidal intranasal meningocele in an adult with recurrent meningitis. J Clin Neurosci. 2005;
12(6):702-704. 

4.Kishikawa K, Nagao T, Ibayashi S, et al. An adult case of basal encephalomeningocele with recurrent meningitis. Rinsho Shinkeigaku. 1994;34(9):908-910.