Tension pneumoventricle in a patient with a ventriculoperitoneal shunt and an ethmoidal meningoencephalocele

Abstract

Background: Tension pneumoventricle is a rare, life-threatening complication. It has been rarely described in patients with ventriculoperitoneal (VP) shunts.

Case description: A 28-year-old male patient with a VP shunt became progressively lethargic after falling from his wheelchair. Skull X-rays and head CT scan showed abundant air inside the ventricles. He was taken to the operating room, and the shunt was revised without improvement. Two days later, a frontal external ventricular drain was placed to remove the air. In the investigation toward the etiology of the pneumoventricle, a review of previous head CT scans and brain MRIs showed that the patient had a small left frontonasal meningoencephalocele extending into the ethmoid, which had been unnoticed. He underwent repair of the defect with adequate sealing of the frontal skull base.

Conclusion: In a shunted patient with moderate or severe symptoms from a tension pneumoventricle, external ventricular drainage is required to remove the air as the shunt is inadequate.

Keywords: Ethmoid; Meningoencephalocele; Pneumoventricle; Tension; Ventriculoperitoneal shunt.

Figure 1:

Axial T1-weighted brain MRI with contrast shows a large left cerebellar arteriovenous malformation.

Figure 2:

Skull X-rays films (a) anteroposterior view and (b) lateral view showing abundant air inside the ventricles (black arrow).

Figure 3:

Head CT scan reconstruction images (a) coronal brain window view, (b) coronal bone window view, and (c) sagittal bone window view showing the left ethmoidal meningoencephalocele (yellow arrow) and the fistulous air tract extending into the ventricle (red arrow).

Figure 4:

Coronal T2-weighted brain MRI (left and right) shows a small left frontobasal meningoencephalocele herniating into the ethmoid (yellow arrow).